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Sample records for eyeblink conditioning emg

  1. Recruitment in Retractor Bulbi Muscle During Eyeblink Conditioning: EMG Analysis and Common-Drive Model

    PubMed Central

    Lepora, N. F.; Porrill, J.; Yeo, C. H.; Evinger, C.

    2009-01-01

    To analyze properly the role of the cerebellum in classical conditioning of the eyeblink and nictitating membrane (NM) response, the control of conditioned response dynamics must be better understood. Previous studies have suggested that the control signal is linearly related to the CR as a result of recruitment within the accessory abducens motoneuron pool, which acts to linearize retractor bulbi muscle and NM response mechanics. Here we investigate possible recruitment mechanisms. Data came from simultaneous recordings of NM position and multiunit electromyographic (EMG) activity from the retractor bulbi muscle of rabbits during eyeblink conditioning, in which tone and periocular shock act as conditional and unconditional stimuli, respectively. Action potentials (spikes) were extracted and classified by amplitude. Firing rates of spikes with different amplitudes were analyzed with respect to NM response temporal profiles and total EMG spike firing rate. Four main regularities were revealed and quantified: 1) spike amplitude increased with response amplitude; 2) smaller spikes always appeared before larger spikes; 3) subsequent firing rates covaried for spikes of different amplitude, with smaller spikes always firing at higher rates than larger ones; and 4) firing-rate profiles were approximately Gaussian for all amplitudes. These regularities suggest that recruitment does take place in the retractor bulbi muscle during conditioned NM responses and that all motoneurons receive the same command signal (common-drive hypothesis). To test this hypothesis, a model of the motoneuron pool was constructed in which motoneurons had a range of intrinsic thresholds distributed exponentially, with threshold linearly related to EMG spike amplitude. Each neuron received the same input signal as required by the common-drive assumption. This simple model reproduced the main features of the data, suggesting that conditioned NM responses are controlled by a common-drive mechanism

  2. Eyeblink conditioning in the developing rabbit

    PubMed Central

    Brown, Kevin L.; Woodruff-Pak, Diana S.

    2011-01-01

    Eyeblink classical conditioning in pre-weanling rabbits was examined in the present study. Using a custom lightweight headpiece and restrainer, New Zealand white littermates were trained once daily in 400 ms delay eyeblink classical conditioning from postnatal days (PD) 17–21 or PD 24–28. These ages were chosen because eyeblink conditioning emerges gradually over PD 17–24 in rats (Stanton, Freeman, & Skelton, 1992), another altricial species with neurodevelopmental features similar to those of rabbits. Consistent with well-established findings in rats, rabbits trained from PD 24–28 showed greater conditioning relative to littermates trained from PD 17–21. Both age groups displayed poor retention of eyeblink conditioning at retraining one month after acquisition. These findings are the first to demonstrate eyeblink conditioning in the developing rabbit. With further characterization of optimal conditioning parameters, this preparation may have applications to neurodevelopmental disease models as well as research exploring the ontogeny of memory. PMID:21953433

  3. Cerebellar Secretin Modulates Eyeblink Classical Conditioning

    ERIC Educational Resources Information Center

    Fuchs, Jason R.; Robinson, Gain M.; Dean, Aaron M.; Schoenberg, Heidi E.; Williams, Michael R.; Morielli, Anthony D.; Green, John T.

    2014-01-01

    We have previously shown that intracerebellar infusion of the neuropeptide secretin enhances the acquisition phase of eyeblink conditioning (EBC). Here, we sought to test whether endogenous secretin also regulates EBC and to test whether the effect of exogenous and endogenous secretin is specific to acquisition. In Experiment 1, rats received…

  4. Cerebellar Secretin Modulates Eyeblink Classical Conditioning

    ERIC Educational Resources Information Center

    Fuchs, Jason R.; Robinson, Gain M.; Dean, Aaron M.; Schoenberg, Heidi E.; Williams, Michael R.; Morielli, Anthony D.; Green, John T.

    2014-01-01

    We have previously shown that intracerebellar infusion of the neuropeptide secretin enhances the acquisition phase of eyeblink conditioning (EBC). Here, we sought to test whether endogenous secretin also regulates EBC and to test whether the effect of exogenous and endogenous secretin is specific to acquisition. In Experiment 1, rats received…

  5. Ontogeny of eyeblink conditioning using a visual conditional stimulus.

    PubMed

    Paczkowski, C; Ivkovich, D; Stanton, M E

    1999-12-01

    The developmental emergence of associative learning in rodents is determined by interactions among sensory, motor, and associative systems that are engaged in a particular experimental preparation (Carter & Stanton, 1996; Hunt & Campbell, 1997; Rudy, 1992). In fear conditioning, chemosensory, auditory, and visual cues emerge successively as effective conditional stimuli (CS) during postnatal ontogeny. In the present study, we begin to examine the generality of this principle of sensory system development for eyeblink conditioning, a form of associative learning that develops substantially later than conditioned fear (Carter & Stanton, 1996). We asked whether the developmental emergence of eyeblink conditioning to a visual CS occurs at an age that is the same or different from conditioning to an auditory CS. In Experiment 1, rat pups were trained on postnatal Day 17 or 24 with experimental parameters (and design) that were identical to our previous studies of eyeblink conditioning except that presentation of a light rather than a tone served as the CS. The outcome was also identical: no eyeblink conditioning on Day 17 and strong conditioning on Day 24. In Experiment 2, conditioning to tone versus light was directly compared by means of a discrimination learning design on postnatal Days 19, 21, 23, and 31. There was no evidence for differential development of auditory versus visual eyeblink conditioning. The difference between this outcome and previous ones involving conditioned fear (Hunt & Campbell, 1997; Rudy, 1992) suggests that principles concerning sensory maturation and learning may be different for early- versus late-developing associative systems.

  6. Neural Circuitry and Plasticity Mechanisms Underlying Delay Eyeblink Conditioning

    ERIC Educational Resources Information Center

    Freeman, John H.; Steinmetz, Adam B.

    2011-01-01

    Pavlovian eyeblink conditioning has been used extensively as a model system for examining the neural mechanisms underlying associative learning. Delay eyeblink conditioning depends on the intermediate cerebellum ipsilateral to the conditioned eye. Evidence favors a two-site plasticity model within the cerebellum with long-term depression of…

  7. Parallel Acquisition of Awareness and Differential Delay Eyeblink Conditioning

    ERIC Educational Resources Information Center

    Weidemann, Gabrielle; Antees, Cassandra

    2012-01-01

    There is considerable debate about whether differential delay eyeblink conditioning can be acquired without awareness of the stimulus contingencies. Previous investigations of the relationship between differential-delay eyeblink conditioning and awareness of the stimulus contingencies have assessed awareness after the conditioning session was…

  8. Neural Circuitry and Plasticity Mechanisms Underlying Delay Eyeblink Conditioning

    ERIC Educational Resources Information Center

    Freeman, John H.; Steinmetz, Adam B.

    2011-01-01

    Pavlovian eyeblink conditioning has been used extensively as a model system for examining the neural mechanisms underlying associative learning. Delay eyeblink conditioning depends on the intermediate cerebellum ipsilateral to the conditioned eye. Evidence favors a two-site plasticity model within the cerebellum with long-term depression of…

  9. Parallel Acquisition of Awareness and Differential Delay Eyeblink Conditioning

    ERIC Educational Resources Information Center

    Weidemann, Gabrielle; Antees, Cassandra

    2012-01-01

    There is considerable debate about whether differential delay eyeblink conditioning can be acquired without awareness of the stimulus contingencies. Previous investigations of the relationship between differential-delay eyeblink conditioning and awareness of the stimulus contingencies have assessed awareness after the conditioning session was…

  10. Ontogeny of septohippocampal modulation of delay eyeblink conditioning.

    PubMed

    Harmon, Thomas C; Freeman, John H

    2015-03-01

    The current study investigated the effects of disrupting the septohippocampal theta system on the developmental emergence of delay eyeblink conditioning. Theta oscillations are defined as electroencephalographic (EEG) waveforms with a frequency between 3-8 Hz. Hippocampal theta oscillations are generated by inputs from the entorhinal cortex and the medial septum. Theta activity has been shown to facilitate learning in a variety of paradigms, including delay eyeblink conditioning. Lesions of the medial septum disrupt theta activity and slow the rate at which delay eyeblink conditioning is learned (Berry & Thompson, [1979] Science 200:1298-1300). The role of the septohippocampal theta system in the ontogeny of eyeblink conditioning has not been examined. In the current study, infant rats received an electrolytic lesion of the medial septum on postnatal day (P) 12. Rats were later given eyeblink conditioning for 6 sessions with an auditory conditioned stimulus on P17-19, P21-23, or P24-26. Lesions impaired eyeblink conditioning on P21-23 and P24-26 but not on P17-19. The results suggest that the septohippocampal system comes online to facilitate acquisition of eyeblink conditioning between P19 and P21. Developmental changes in septohippocampal modulation of the cerebellum may play a significant role in the ontogeny of eyeblink conditioning.

  11. Parallel acquisition of awareness and trace eyeblink classical conditioning.

    PubMed

    Manns, J R; Clark, R E; Squire, L R

    2000-01-01

    Trace eyeblink conditioning (with a trace interval >/=500 msec) depends on the integrity of the hippocampus and requires that participants develop awareness of the stimulus contingencies (i.e., awareness that the conditioned stimulus [CS] predicts the unconditioned stimulus [US]). Previous investigations of the relationship between trace eyeblink conditioning and awareness of the stimulus contingencies have manipulated awareness or have assessed awareness at fixed intervals during and after the conditioning session. In this study, we tracked the development of knowledge about the stimulus contingencies trial by trial by asking participants to try to predict either the onset of the US or the onset of their eyeblinks during differential trace eyeblink conditioning. Asking participants to predict their eyeblinks inhibited both the acquisition of awareness and eyeblink conditioning. In contrast, asking participants to predict the onset of the US promoted awareness and facilitated conditioning. Acquisition of knowledge about the stimulus contingencies and acquisition of differential trace eyeblink conditioning developed approximately in parallel (i.e., concurrently).

  12. Eyeblink Conditioning in Schizophrenia: A Critical Review

    PubMed Central

    Kent, Jerillyn S.; Bolbecker, Amanda R.; O’Donnell, Brian F.; Hetrick, William P.

    2015-01-01

    There is accruing evidence of cerebellar abnormalities in schizophrenia. The theory of cognitive dysmetria considers cerebellar dysfunction a key component of schizophrenia. Delay eyeblink conditioning (EBC), a cerebellar-dependent translational probe, is a behavioral index of cerebellar integrity. The circuitry underlying EBC has been well characterized by non-human animal research, revealing the cerebellum as the essential circuitry for the associative learning instantiated by this task. However, there have been persistent inconsistencies in EBC findings in schizophrenia. This article thoroughly reviews published studies investigating EBC in schizophrenia, with an emphasis on possible effects of antipsychotic medication and stimulus and analysis parameters on reports of EBC performance in schizophrenia. Results indicate a consistent finding of impaired EBC performance in schizophrenia, as measured by decreased rates of conditioning, and that medication or study design confounds do not account for this impairment. Results are discussed within the context of theoretical and neurochemical models of schizophrenia. PMID:26733890

  13. Cerebellar secretin modulates eyeblink classical conditioning

    PubMed Central

    Fuchs, Jason R.; Robinson, Gain M.; Dean, Aaron M.; Schoenberg, Heidi E.; Williams, Michael R.; Morielli, Anthony D.

    2014-01-01

    We have previously shown that intracerebellar infusion of the neuropeptide secretin enhances the acquisition phase of eyeblink conditioning (EBC). Here, we sought to test whether endogenous secretin also regulates EBC and to test whether the effect of exogenous and endogenous secretin is specific to acquisition. In Experiment 1, rats received intracerebellar infusions of the secretin receptor antagonist 5-27 secretin or vehicle into the lobulus simplex of cerebellar cortex immediately prior to sessions 1–3 of acquisition. Antagonist-infused rats showed a reduction in the percentage of eyeblink CRs compared with vehicle-infused rats. In Experiment 2, rats received intracerebellar infusions of secretin or vehicle immediately prior to sessions 1–2 of extinction. Secretin did not significantly affect extinction performance. In Experiment 3, rats received intracerebellar infusions of 5-27 secretin or vehicle immediately prior to sessions 1–2 of extinction. The secretin antagonist did not significantly affect extinction performance. Together, our current and previous results indicate that both exogenous and endogenous cerebellar secretin modulate acquisition, but not extinction, of EBC. We have previously shown that (1) secretin reduces surface expression of the voltage-gated potassium channel α-subunit Kv1.2 in cerebellar cortex and (2) intracerebellar infusions of a Kv1.2 blocker enhance EBC acquisition, much like secretin. Kv1.2 is almost exclusively expressed in cerebellar cortex at basket cell–Purkinje cell pinceaus and Purkinje cell dendrites; we propose that EBC-induced secretin release from PCs modulates EBC acquisition by reducing surface expression of Kv1.2 at one or both of these sites. PMID:25403455

  14. Neural circuitry and plasticity mechanisms underlying delay eyeblink conditioning

    PubMed Central

    Freeman, John H.; Steinmetz, Adam B.

    2011-01-01

    Pavlovian eyeblink conditioning has been used extensively as a model system for examining the neural mechanisms underlying associative learning. Delay eyeblink conditioning depends on the intermediate cerebellum ipsilateral to the conditioned eye. Evidence favors a two-site plasticity model within the cerebellum with long-term depression of parallel fiber synapses on Purkinje cells and long-term potentiation of mossy fiber synapses on neurons in the anterior interpositus nucleus. Conditioned stimulus and unconditioned stimulus inputs arise from the pontine nuclei and inferior olive, respectively, converging in the cerebellar cortex and deep nuclei. Projections from subcortical sensory nuclei to the pontine nuclei that are necessary for eyeblink conditioning are beginning to be identified, and recent studies indicate that there are dynamic interactions between sensory thalamic nuclei and the cerebellum during eyeblink conditioning. Cerebellar output is projected to the magnocellular red nucleus and then to the motor nuclei that generate the blink response(s). Tremendous progress has been made toward determining the neural mechanisms of delay eyeblink conditioning but there are still significant gaps in our understanding of the necessary neural circuitry and plasticity mechanisms underlying cerebellar learning. PMID:21969489

  15. Caffeine has no effect on eyeblink conditioning in mice.

    PubMed

    Rasmussen, Anders; Ijpelaar, Anna C H G; De Zeeuw, Chris I; Boele, Henk-Jan

    2017-09-08

    Caffeine is one of the most widely used drugs in the world. In the brain, caffeine acts as an antagonist for the adenosine A1 and A2B receptors. Since A1 receptors are highly concentrated in the cortex of the cerebellum, we hypothesized that caffeine could potentially affect learning tasks that require the cerebellar cortex, such as eyeblink conditioning. To test this hypothesis, we examined the effect of low (5mg/kg) and high (50mg/kg) doses of caffeine, injected intraperitoneally before training, on eyeblink conditioning in mice. The results show that, at the dosages we used, caffeine affects neither the rate of acquisition, nor the timing of the onset or peak of the conditioned blink responses. Therefore, we conclude that caffeine neither improves nor worsens performance on eyeblink conditioning. Copyright © 2017 Elsevier B.V. All rights reserved.

  16. Central Cannabinoid Receptors Modulate Acquisition of Eyeblink Conditioning

    ERIC Educational Resources Information Center

    Steinmetz, Adam B.; Freeman, John H.

    2010-01-01

    Delay eyeblink conditioning is established by paired presentations of a conditioned stimulus (CS) such as a tone or light, and an unconditioned stimulus (US) that elicits the blink reflex. Conditioned stimulus information is projected from the basilar pontine nuclei to the cerebellar interpositus nucleus and cortex. The cerebellar cortex,…

  17. Central Cannabinoid Receptors Modulate Acquisition of Eyeblink Conditioning

    ERIC Educational Resources Information Center

    Steinmetz, Adam B.; Freeman, John H.

    2010-01-01

    Delay eyeblink conditioning is established by paired presentations of a conditioned stimulus (CS) such as a tone or light, and an unconditioned stimulus (US) that elicits the blink reflex. Conditioned stimulus information is projected from the basilar pontine nuclei to the cerebellar interpositus nucleus and cortex. The cerebellar cortex,…

  18. Eyeblink Conditioning: A Non-Invasive Biomarker for Neurodevelopmental Disorders

    ERIC Educational Resources Information Center

    Reeb-Sutherland, Bethany C.; Fox, Nathan A.

    2015-01-01

    Eyeblink conditioning (EBC) is a classical conditioning paradigm typically used to study the underlying neural processes of learning and memory. EBC has a well-defined neural circuitry, is non-invasive, and can be employed in human infants shortly after birth making it an ideal tool to use in both developing and special populations. In addition,…

  19. Eyeblink Conditioning: A Non-Invasive Biomarker for Neurodevelopmental Disorders

    ERIC Educational Resources Information Center

    Reeb-Sutherland, Bethany C.; Fox, Nathan A.

    2015-01-01

    Eyeblink conditioning (EBC) is a classical conditioning paradigm typically used to study the underlying neural processes of learning and memory. EBC has a well-defined neural circuitry, is non-invasive, and can be employed in human infants shortly after birth making it an ideal tool to use in both developing and special populations. In addition,…

  20. Accelerated trace eyeblink conditioning after cortisol IV-infusion.

    PubMed

    Kuehl, Linn K; Lass-Hennemann, Johanna; Richter, Steffen; Blumenthal, Terry D; Oitzl, Melly; Schachinger, Hartmut

    2010-11-01

    Impairing effects of cortisol on learning performance have been shown in human trace eyeblink conditioning. As the effect is observed from 30 min to hours after administration, a genomic action of cortisol is assumed. Here we report rapid cortisol effects that were observed during the first 10 min after cortisol administration in humans. Young healthy males (n=24) received the cortisol synthesis inhibitor metyrapone (1.5 g per os) to avoid interference of the endogenous pulsatile secretion of cortisol. Next, 2mg cortisol or placebo was infused intravenously, immediately before the trace conditioning task. The probability of the conditioned eyeblink responses was assessed electromyographically during the trace eyeblink conditioning task (unconditioned stimulus: corneal air puff, 10 psi, 50 ms; conditioned stimulus: binaural pure tone, 7 dB, 1000 Hz, 400 ms; empty interval between CS and US: 550 ms). Cortisol resulted in a faster increase of conditioning (p=.02), reaching a comparable level to placebo later on. This result extends the well-known effects of stress on the quality and amount of learning by showing that cortisol also affects the speed of learning. We propose that cortisol accelerates trace eyeblink conditioning via a fast, non-genomic mechanism. This fast action of cortisol is part of the adaptive strategy during the early stress response.

  1. Ontogenetic Change in the Auditory Conditioned Stimulus Pathway for Eyeblink Conditioning

    ERIC Educational Resources Information Center

    Freeman, John H.; Campolattaro, Matthew M.

    2008-01-01

    Two experiments examined the neural mechanisms underlying the ontogenetic emergence of auditory eyeblink conditioning. Previous studies found that the medial auditory thalamus is necessary for eyeblink conditioning with an auditory conditioned stimulus (CS) in adult rats. In experiment 1, stimulation of the medial auditory thalamus was used as a…

  2. Blocking the BK Channel Impedes Acquisition of Trace Eyeblink Conditioning

    ERIC Educational Resources Information Center

    Matthews, Elizabeth A.; Disterhoft, John F.

    2009-01-01

    Big-K[superscript +] conductance (BK)-channel mediated fast afterhyperpolarizations (AHPs) following action potentials are reduced after eyeblink conditioning. Blocking BK channels with paxilline increases evoked firing frequency in vitro and spontaneous pyramidal activity in vivo. To examine how increased excitability after BK-channel blockade…

  3. Eyeblink Conditioning Deficits Indicate Timing and Cerebellar Abnormalities in Schizophrenia

    ERIC Educational Resources Information Center

    Brown, S.M.; Kieffaber, P.D.; Carroll, C.A.; Vohs, J.L.; Tracy, J.A.; Shekhar, A.; O'Donnell, B.F.; Steinmetz, J.E.; Hetrick, W.P.

    2005-01-01

    Accumulating evidence indicates that individuals with schizophrenia manifest abnormalities in structures (cerebellum and basal ganglia) and neurotransmitter systems (dopamine) linked to internal-timing processes. A single-cue tone delay eyeblink conditioning paradigm comprised of 100 learning and 50 extinction trials was used to examine cerebellar…

  4. Eyeblink Conditioning Deficits Indicate Timing and Cerebellar Abnormalities in Schizophrenia

    ERIC Educational Resources Information Center

    Brown, S.M.; Kieffaber, P.D.; Carroll, C.A.; Vohs, J.L.; Tracy, J.A.; Shekhar, A.; O'Donnell, B.F.; Steinmetz, J.E.; Hetrick, W.P.

    2005-01-01

    Accumulating evidence indicates that individuals with schizophrenia manifest abnormalities in structures (cerebellum and basal ganglia) and neurotransmitter systems (dopamine) linked to internal-timing processes. A single-cue tone delay eyeblink conditioning paradigm comprised of 100 learning and 50 extinction trials was used to examine cerebellar…

  5. Inferior Colliculus Lesions Impair Eyeblink Conditioning in Rats

    ERIC Educational Resources Information Center

    Freeman, John H.; Halverson, Hunter E.; Hubbard, Erin M.

    2007-01-01

    The neural plasticity necessary for acquisition and retention of eyeblink conditioning has been localized to the cerebellum. However, the sources of sensory input to the cerebellum that are necessary for establishing learning-related plasticity have not been identified completely. The inferior colliculus may be a source of sensory input to the…

  6. Blocking the BK Channel Impedes Acquisition of Trace Eyeblink Conditioning

    ERIC Educational Resources Information Center

    Matthews, Elizabeth A.; Disterhoft, John F.

    2009-01-01

    Big-K[superscript +] conductance (BK)-channel mediated fast afterhyperpolarizations (AHPs) following action potentials are reduced after eyeblink conditioning. Blocking BK channels with paxilline increases evoked firing frequency in vitro and spontaneous pyramidal activity in vivo. To examine how increased excitability after BK-channel blockade…

  7. Inferior Colliculus Lesions Impair Eyeblink Conditioning in Rats

    ERIC Educational Resources Information Center

    Freeman, John H.; Halverson, Hunter E.; Hubbard, Erin M.

    2007-01-01

    The neural plasticity necessary for acquisition and retention of eyeblink conditioning has been localized to the cerebellum. However, the sources of sensory input to the cerebellum that are necessary for establishing learning-related plasticity have not been identified completely. The inferior colliculus may be a source of sensory input to the…

  8. Inhibition of classically conditioned eyeblink responses by stimulation of the cerebellar cortex in the decerebrate cat.

    PubMed

    Hesslow, G

    1994-04-15

    The purpose of the present study was to test the hypothesis that neurones in the anterior interpositus nucleus, under the control of Purkinje cells in the c1 and c3 zones of the cerebellar cortex, exert some control over classically conditioned responses. In particular, the experiments were designed to determine whether the cerebellar control of conditioned and unconditioned responses is different. The experiments were performed on cats decerebrated rostral to the red nucleus under halothane anaesthesia. The cats were conditioned using either a 1000 Hz tone or trains of stimuli through the skin of the proximal forelimb as the conditioned stimulus, and periorbital electrical stimulation as the unconditioned stimulus. A large proportion of the animals acquired conditioned responses at normal rates. It could be shown that these were true conditioned responses and did not result from sensitization or pseudoconditioning. For instance, unpaired presentations of conditioned and unconditioned stimuli caused rapid extinction. Cerebellar areas controlling eyeblink were identified by recording climbing fibre responses in the cerebellar cortex and recording EMG activity in the eyelid evoked by stimulation of the cerebellar cortex. When single shocks of 40-70 microA were applied to these areas during the emission of conditioned eyeblink responses, the latter were strongly inhibited. The inhibition had a latency of about 10 ms and a duration of 25-75 ms. It was shown that this inhibition of the conditioned responses was topographically specific and could only be evoked from cortical sites identified as controlling eyeblink. Stimulation of the periphery of an eyeblink area caused little or no inhibition. The effect of cortical stimulation on unconditioned reflex responses in the orbicularis oculi muscle was also tested. Some inhibition of unconditioned responses was observed, but quantitative analysis showed that this inhibition was considerably weaker than the corresponding

  9. Inhibition of classically conditioned eyeblink responses by stimulation of the cerebellar cortex in the decerebrate cat.

    PubMed Central

    Hesslow, G

    1994-01-01

    The purpose of the present study was to test the hypothesis that neurones in the anterior interpositus nucleus, under the control of Purkinje cells in the c1 and c3 zones of the cerebellar cortex, exert some control over classically conditioned responses. In particular, the experiments were designed to determine whether the cerebellar control of conditioned and unconditioned responses is different. The experiments were performed on cats decerebrated rostral to the red nucleus under halothane anaesthesia. The cats were conditioned using either a 1000 Hz tone or trains of stimuli through the skin of the proximal forelimb as the conditioned stimulus, and periorbital electrical stimulation as the unconditioned stimulus. A large proportion of the animals acquired conditioned responses at normal rates. It could be shown that these were true conditioned responses and did not result from sensitization or pseudoconditioning. For instance, unpaired presentations of conditioned and unconditioned stimuli caused rapid extinction. Cerebellar areas controlling eyeblink were identified by recording climbing fibre responses in the cerebellar cortex and recording EMG activity in the eyelid evoked by stimulation of the cerebellar cortex. When single shocks of 40-70 microA were applied to these areas during the emission of conditioned eyeblink responses, the latter were strongly inhibited. The inhibition had a latency of about 10 ms and a duration of 25-75 ms. It was shown that this inhibition of the conditioned responses was topographically specific and could only be evoked from cortical sites identified as controlling eyeblink. Stimulation of the periphery of an eyeblink area caused little or no inhibition. The effect of cortical stimulation on unconditioned reflex responses in the orbicularis oculi muscle was also tested. Some inhibition of unconditioned responses was observed, but quantitative analysis showed that this inhibition was considerably weaker than the corresponding

  10. Implicit Memory in Monkeys: Development of a Delay Eyeblink Conditioning System with Parallel Electromyographic and High-Speed Video Measurements.

    PubMed

    Kishimoto, Yasushi; Yamamoto, Shigeyuki; Suzuki, Kazutaka; Toyoda, Haruyoshi; Kano, Masanobu; Tsukada, Hideo; Kirino, Yutaka

    2015-01-01

    Delay eyeblink conditioning, a cerebellum-dependent learning paradigm, has been applied to various mammalian species but not yet to monkeys. We therefore developed an accurate measuring system that we believe is the first system suitable for delay eyeblink conditioning in a monkey species (Macaca mulatta). Monkey eyeblinking was simultaneously monitored by orbicularis oculi electromyographic (OO-EMG) measurements and a high-speed camera-based tracking system built around a 1-kHz CMOS image sensor. A 1-kHz tone was the conditioned stimulus (CS), while an air puff (0.02 MPa) was the unconditioned stimulus. EMG analysis showed that the monkeys exhibited a conditioned response (CR) incidence of more than 60% of trials during the 5-day acquisition phase and an extinguished CR during the 2-day extinction phase. The camera system yielded similar results. Hence, we conclude that both methods are effective in evaluating monkey eyeblink conditioning. This system incorporating two different measuring principles enabled us to elucidate the relationship between the actual presence of eyelid closure and OO-EMG activity. An interesting finding permitted by the new system was that the monkeys frequently exhibited obvious CRs even when they produced visible facial signs of drowsiness or microsleep. Indeed, the probability of observing a CR in a given trial was not influenced by whether the monkeys closed their eyelids just before CS onset, suggesting that this memory could be expressed independently of wakefulness. This work presents a novel system for cognitive assessment in monkeys that will be useful for elucidating the neural mechanisms of implicit learning in nonhuman primates.

  11. Localization of the Cerebellar Cortical Zone Mediating Acquisition of Eyeblink Conditioning in Rats

    PubMed Central

    Steinmetz, Adam B.; Freeman, John H.

    2014-01-01

    Delay eyeblink conditioning is established by paired presentations of a conditioned stimulus (CS) such as a tone or light and an unconditioned stimulus (US) that elicits eyelid closure before training. The CS and US inputs converge on Purkinje cells in the cerebellar cortex. The cerebellar cortex plays a substantial role in acquisition of delay eyeblink conditioning in rabbits and rodents, but the specific area of the cortex that is necessary for acquisition in rodents has not been identified. A recent study identified an eyeblink microzone in the mouse cerebellar cortex at the base of the primary fissure (Heiney, Kim, Augustine, & Medina, 2014). There is no evidence that the cortex in this eyeblink microzone plays a role in rodent eyeblink conditioning but it is a good candidate region. Experiment 1 examined the effects of unilateral (ipsilateral to the US) lesions of lobule HVI, the lateral anterior lobe, or the base of the primary fissure on eyeblink conditioning in rats. Lesions of either the anterior lobe or lobule HVI impaired acquisition, but lesions of the base of the primary fissure produced the largest deficit. Experiment 2 used reversible inactivation with muscimol to demonstrate that inactivation of the putative eyeblink microzone severely impaired acquisition and had only a modest effect on retention of eyeblink conditioning. The findings indicate that the base of the primary fissure is the critical zone of the cerebellar cortex for acquisition of eyeblink conditioning in rats. PMID:24931828

  12. Ventral Lateral Geniculate Input to the Medial Pons Is Necessary for Visual Eyeblink Conditioning in Rats

    ERIC Educational Resources Information Center

    Halverson, Hunter E.; Freeman, John H.

    2010-01-01

    The conditioned stimulus (CS) pathway that is necessary for visual delay eyeblink conditioning was investigated in the current study. Rats were initially given eyeblink conditioning with stimulation of the ventral nucleus of the lateral geniculate (LGNv) as the CS followed by conditioning with light and tone CSs in separate training phases.…

  13. Ventral Lateral Geniculate Input to the Medial Pons Is Necessary for Visual Eyeblink Conditioning in Rats

    ERIC Educational Resources Information Center

    Halverson, Hunter E.; Freeman, John H.

    2010-01-01

    The conditioned stimulus (CS) pathway that is necessary for visual delay eyeblink conditioning was investigated in the current study. Rats were initially given eyeblink conditioning with stimulation of the ventral nucleus of the lateral geniculate (LGNv) as the CS followed by conditioning with light and tone CSs in separate training phases.…

  14. Contextual Specificity of Extinction of Delay but Not Trace Eyeblink Conditioning in Humans

    ERIC Educational Resources Information Center

    Grillon, Christian; Alvarez, Ruben P.; Johnson, Linda; Chavis, Chanen

    2008-01-01

    Renewal of an extinguished conditioned response has been demonstrated in humans and in animals using various types of procedures, except renewal of motor learning such as eyeblink conditioning. We tested renewal of delay and trace eyeblink conditioning in a virtual environment in an ABA design. Following acquisition in one context (A, e.g., an…

  15. Contextual Specificity of Extinction of Delay but Not Trace Eyeblink Conditioning in Humans

    ERIC Educational Resources Information Center

    Grillon, Christian; Alvarez, Ruben P.; Johnson, Linda; Chavis, Chanen

    2008-01-01

    Renewal of an extinguished conditioned response has been demonstrated in humans and in animals using various types of procedures, except renewal of motor learning such as eyeblink conditioning. We tested renewal of delay and trace eyeblink conditioning in a virtual environment in an ABA design. Following acquisition in one context (A, e.g., an…

  16. Extinction, Reacquisition, and Rapid Forgetting of Eyeblink Conditioning in Developing Rats

    ERIC Educational Resources Information Center

    Brown, Kevin L.; Freeman, John H.

    2014-01-01

    Eyeblink conditioning is a well-established model for studying the developmental neurobiology of associative learning and memory. However, age differences in extinction and subsequent reacquisition have yet to be studied using this model. The present study examined extinction and reacquisition of eyeblink conditioning in developing rats. In…

  17. Retention and Extinction of Delay Eyeblink Conditioning Are Modulated by Central Cannabinoids

    ERIC Educational Resources Information Center

    Steinmetz, Adam B.; Freeman, John H.

    2011-01-01

    Rats administered the cannabinoid agonist WIN55,212-2 or the antagonist SR141716A exhibit marked deficits during acquisition of delay eyeblink conditioning, as noted by Steinmetz and Freeman in an earlier study. However, the effects of these drugs on retention and extinction of eyeblink conditioning have not been assessed. The present study…

  18. Extinction, Reacquisition, and Rapid Forgetting of Eyeblink Conditioning in Developing Rats

    ERIC Educational Resources Information Center

    Brown, Kevin L.; Freeman, John H.

    2014-01-01

    Eyeblink conditioning is a well-established model for studying the developmental neurobiology of associative learning and memory. However, age differences in extinction and subsequent reacquisition have yet to be studied using this model. The present study examined extinction and reacquisition of eyeblink conditioning in developing rats. In…

  19. Retention and Extinction of Delay Eyeblink Conditioning Are Modulated by Central Cannabinoids

    ERIC Educational Resources Information Center

    Steinmetz, Adam B.; Freeman, John H.

    2011-01-01

    Rats administered the cannabinoid agonist WIN55,212-2 or the antagonist SR141716A exhibit marked deficits during acquisition of delay eyeblink conditioning, as noted by Steinmetz and Freeman in an earlier study. However, the effects of these drugs on retention and extinction of eyeblink conditioning have not been assessed. The present study…

  20. Medial Auditory Thalamic Stimulation as a Conditioned Stimulus for Eyeblink Conditioning in Rats

    ERIC Educational Resources Information Center

    Campolattaro, Matthew M.; Halverson, Hunter E.; Freeman, John H.

    2007-01-01

    The neural pathways that convey conditioned stimulus (CS) information to the cerebellum during eyeblink conditioning have not been fully delineated. It is well established that pontine mossy fiber inputs to the cerebellum convey CS-related stimulation for different sensory modalities (e.g., auditory, visual, tactile). Less is known about the…

  1. Medial Auditory Thalamic Stimulation as a Conditioned Stimulus for Eyeblink Conditioning in Rats

    ERIC Educational Resources Information Center

    Campolattaro, Matthew M.; Halverson, Hunter E.; Freeman, John H.

    2007-01-01

    The neural pathways that convey conditioned stimulus (CS) information to the cerebellum during eyeblink conditioning have not been fully delineated. It is well established that pontine mossy fiber inputs to the cerebellum convey CS-related stimulation for different sensory modalities (e.g., auditory, visual, tactile). Less is known about the…

  2. Sensory system development influences the ontogeny of eyeblink conditioning.

    PubMed

    Goldsberry, Mary E; Elkin, Magdalyn E; Freeman, John H

    2014-09-01

    A rate-limiting factor in the ontogeny of auditory eyeblink conditioning (EBC) is the development of sensory inputs to the pontine nucleus. One possible way to facilitate the emergence of EBC would be to use a conditioned stimulus (CS) that activates an earlier-developing sensory system. The goal of the current study was to investigate whether using a vibration CS would facilitate the ontogeny of delay EBC relative to an auditory CS. Rat pups received six sessions of delay EBC or unpaired training using either a tone or vibration CS on postnatal day (P)14-15, 17-18, 21-22, or 24-25. Conditioning with a vibration CS resulted in rapid learning as early as P17-18, whereas conditioning with a tone CS did not result in rapid conditioning until after P17-18. Control experiments verified that the differences in EBC were due to CS-specific sensory properties. The results suggest that the ontogeny of EBC depends on sensory system development.

  3. Subject expectancy effects in frontal EMG conditioning.

    PubMed

    Kotses, H; Segreto-Bures, J

    1983-01-01

    The influence of subject expectancies on performance has been examined extensively within the framework of behavior therapy but has received little attention within the context of EMG training. This study assessed the effects of subject expectancy on acquisition during frontal EMG conditioning. Prior to conditioning, subjects were either given no expectancy or instructed that learning to control the feedback stimulus would be either easy (high expectancy) or difficult (low expectancy). Subjects in the three expectancy conditions then underwent 20 min of contingent reinforcement for frontal EMG decreases. Three similar groups of no, low, or high expectancy subjects received noncontingent reinforcement. Differential EMG behavior was exhibited between the two no-expectancy groups, with the contingent group reliably lower in EMG activity than that noncontingent. However, differences were not observed between contingent and noncontingent subjects given either low or high expectancy sets. None of the groups could be differentiated on the basis of subjective variables such as anxiety, relaxation, or frustration. These findings suggest that subject expectancies, either positive or negative, interfere with the acquisition of conditioned EMG behavior.

  4. Cerebellar-Dependent Eyeblink Conditioning Deficits in Schizophrenia Spectrum Disorders

    PubMed Central

    Forsyth, Jennifer K.; Bolbecker, Amanda R.; Mehta, Crystal S.; Klaunig, Mallory J.; Steinmetz, Joseph E.; O'Donnell, Brian F.; Hetrick, William P.

    2012-01-01

    Accumulating evidence suggests that abnormalities in neural circuitry and timing associated with the cerebellum may play a role in the pathophysiology of schizophrenia. Schizotypal personality disorder (SPD) may be genetically linked to schizophrenia, but individuals with SPD are freer from potential research confounds and may therefore offer insight into psychophysiological correlates of schizophrenia. The present study employed a delay eyeblink conditioning (EBC) procedure to examine cerebellar-dependent learning in schizophrenia, SPD, and healthy control subjects (n = 18 per group) who were matched for age and gender. The conditioned stimulus was a 400-ms tone that coterminated with a 50 ms unconditioned stimulus air puff. Cognitive performance on the Picture Completion, Digit Symbol Coding, Similarities, and Digit Span subscales of the Wechsler Adult Intelligence Scale—Third Edition was also investigated. The schizophrenia and SPD groups demonstrated robust EBC impairment relative to the control subjects; they had significantly fewer conditioned responses (CRs), as well as smaller CR amplitudes. Schizophrenia subjects showed cognitive impairment across subscales compared with SPD and control subjects; SPD subjects showed intermediate performance to schizophrenia and control subjects and performed significantly worse than controls on Picture Completion. Impaired EBC was significantly related to decreased processing speed in schizophrenia spectrum subjects. These findings support the role of altered cortico-cerebellar-thalamic-cortical circuitry in the pathophysiology of schizophrenia spectrum disorders. PMID:21148238

  5. Eyeblink Classical Conditioning in Alcoholism and Fetal Alcohol Spectrum Disorders

    PubMed Central

    Cheng, Dominic T.; Jacobson, Sandra W.; Jacobson, Joseph L.; Molteno, Christopher D.; Stanton, Mark E.; Desmond, John E.

    2015-01-01

    Alcoholism is a debilitating disorder that can take a significant toll on health and professional and personal relationships. Excessive alcohol consumption can have a serious impact on both drinkers and developing fetuses, leading to long-term learning impairments. Decades of research in laboratory animals and humans have demonstrated the value of eyeblink classical conditioning (EBC) as a well-characterized model system to study the neural mechanisms underlying associative learning. Behavioral EBC studies in adults with alcohol use disorders and in children with fetal alcohol spectrum disorders report a clear learning deficit in these two patient populations, suggesting alcohol-related damage to the cerebellum and associated structures. Insight into the neural mechanisms underlying these learning impairments has largely stemmed from laboratory animal studies. In this mini-review, we present and discuss exemplary animal findings and data from patient and neuroimaging studies. An improved understanding of the neural mechanisms underlying learning deficits in EBC related to alcoholism and prenatal alcohol exposure has the potential to advance the diagnoses, treatment, and prevention of these and other pediatric and adult disorders. PMID:26578987

  6. Discrimination Learning and Reversal of the Conditioned Eyeblink Reflex in a Rodent Model of Autism

    PubMed Central

    Stanton, Mark E.; Peloso, Elizabeth; Brown, Kevin L.; Rodier, Patricia

    2007-01-01

    Offspring of rats exposed to valproic acid (VPA) on Gestational Day (GD) 12 have been advocated as a rodent model of autism because they show neuron loss in brainstem nuclei and the cerebellum resembling that seen in human autistic cases [20, 37]. Studies of autistic children have reported alterations in acquisition of classical eyeblink conditioning [40] and in reversal of instrumental discrimination learning [9]. Acquisition of discriminative eyeblink conditioning depends on known brainstem-cerebellar circuitry whereas reversal depends on interactions of this circuitry with the hippocampus and prefrontal cortex. In order to explore behavioral parallels of the VPA rodent model with human autism, the present study exposed pregnant Long-Evans rats to 600 mg/kg VPA on GD12 [cf. 37] and tested their offspring from PND26-31 on discriminative eyeblink conditioning and reversal. VPA rats showed faster eyeblink conditioning, consistent with studies in autistic children [40]. This suggests that previously reported parallels between human autism and the VPA rodent model with respect to injury to brainstem-cerebellar circuitry [37] are accompanied by behavioral parallels when a conditioning task engaging this circuitry is used. VPA rats also showed impaired reversal learning, but this likely reflected “carry-over” of enhanced conditioning during acquisition rather than a reversal learning deficit like that seen in human autism. Further studies of eyeblink conditioning in human autism and in various animal models may help to identify the etiology of this developmental disorder. PMID:17137645

  7. Cerebellar-Dependent Expression of Motor Learning during Eyeblink Conditioning in Head-Fixed Mice

    PubMed Central

    Heiney, Shane A.; Wohl, Margot P.; Chettih, Selmaan N.; Ruffolo, Luis I.

    2014-01-01

    Eyeblink conditioning in restrained rabbits has served as an excellent model of cerebellar-dependent motor learning for many decades. In mice, the role of the cerebellum in eyeblink conditioning is less clear and remains controversial, partly because learning appears to engage fear-related circuits and lesions of the cerebellum do not abolish the learned behavior completely. Furthermore, experiments in mice are performed using freely moving systems, which lack the stability necessary for mapping out the essential neural circuitry with electrophysiological approaches. We have developed a novel apparatus for eyeblink conditioning in head-fixed mice. Here, we show that the performance of mice in our apparatus is excellent and that the learned behavior displays two hallmark features of cerebellar-dependent eyeblink conditioning in rabbits: (1) gradual acquisition; and (2) adaptive timing of conditioned movements. Furthermore, we use a combination of pharmacological inactivation, electrical stimulation, single-unit recordings, and targeted microlesions to demonstrate that the learned behavior is completely dependent on the cerebellum and to pinpoint the exact location in the deep cerebellar nuclei that is necessary. Our results pave the way for using eyeblink conditioning in head-fixed mice as a platform for applying next-generation genetic tools to address molecular and circuit-level questions about cerebellar function in health and disease. PMID:25378152

  8. Acquisition of Differential Delay Eyeblink Classical Conditioning Is Independent of Awareness

    PubMed Central

    Smith, Christine N.; Clark, Robert E.; Manns, Joseph R.; Squire, Larry R.

    2009-01-01

    There has been debate about whether differential delay eyeblink conditioning can be acquired without awareness of the stimulus contingencies. In 4 experiments, the authors reexamined this question. Older participants were tested with a tone and white noise (Experiment 1) or with 2 tones (Experiment 2). In addition, younger participants were tested with 2 tones (Experiment 3) or with 2 tones plus the parameters from an earlier study that had reported a relationship between conditioning and awareness (Experiment 4). Participants who were designated aware of the stimulus contingencies and participants who were designated unaware exhibited equivalent levels of differential eyeblink conditioning. Awareness of stimulus contingencies is not required for differential delay eyeblink conditioning when simple conditioned stimuli are used. PMID:15727514

  9. Is Perruchet's dissociation between eyeblink conditioned responding and outcome expectancy evidence for two learning systems?

    PubMed

    Weidemann, Gabrielle; Tangen, Jason M; Lovibond, Peter F; Mitchell, Christopher J

    2009-04-01

    P. Perruchet (1985b) showed a double dissociation of conditioned responses (CRs) and expectancy for an airpuff unconditioned stimulus (US) in a 50% partial reinforcement schedule in human eyeblink conditioning. In the Perruchet effect, participants show an increase in CRs and a concurrent decrease in expectancy for the airpuff across runs of reinforced trials; conversely, participants show a decrease in CRs and a concurrent increase in expectancy for the airpuff across runs of nonreinforced trials. Three eyeblink conditioning experiments investigated whether the linear trend in eyeblink CRs in the Perruchet effect is a result of changes in associative strength of the conditioned stimulus (CS), US sensitization, or learning the precise timing of the US. Experiments 1 and 2 demonstrated that the linear trend in eyeblink CRs is not the result of US sensitization. Experiment 3 showed that the linear trend in eyeblink CRs is present with both a fixed and a variable CS-US interval and so is not the result of learning the precise timing of the US. The results are difficult to reconcile with a single learning process model of associative learning in which expectancy mediates CRs. Copyright (c) 2009 APA, all rights reserved.

  10. The Effects of Two Forms of Physical Activity on Eyeblink Classical Conditioning

    PubMed Central

    Green, John T.; Chess, Amy C.; Burns, Montana; Schachinger, Kira M.; Thanellou, Alexandra

    2011-01-01

    Voluntary exercise, in the form of free access to a running wheel in the home cage, has been shown to improve several forms of learning and memory. Acrobatic training, in the form of learning to traverse an elevated obstacle course, has been shown to induce markers of neural plasticity in the cerebellar cortex in rodents. In three experiments, we examined the effects of these two forms of physical activity on delay eyeblink conditioning in rats. In Experiment 1, exercising rats were given 17 days of free access to a running wheel in their home cage prior to 10 days of delay eyeblink conditioning. Rats that exercised conditioned significantly better and showed a larger reflexive eyeblink unconditioned response to the periocular stimulation unconditioned stimulus than rats that did not exercise. In Experiment 2, exercising rats were given 17 days of free access to a running wheel in their home cage prior to 10 days of explicitly unpaired stimulus presentations. Rats that exercised responded the same to tone, light, and periocular stimulation as rats that did not exercise. In Experiment 3, acrobatic training rats were given 15 days of daily training on an elevated obstacle course prior to 10 days of eyeblink conditioning. Activity control rats underwent 15 days of yoked daily running in an open field. Rats that underwent acrobatic training did not differ in eyeblink conditioning from activity control rats. The ability to measure the learned response precisely, and the well-mapped neural circuitry of eyeblink conditioning offer some advantages for the study of exercise effects on learning and memory. PMID:21238502

  11. Eye-Blink Conditioning Is Associated with Changes in Synaptic Ultrastructure in the Rabbit Interpositus Nuclei

    ERIC Educational Resources Information Center

    Weeks, Andrew C. W.; Connor, Steve; Hinchcliff, Richard; LeBoutillier, Janelle C.; Thompson, Richard F.; Petit, Ted L.

    2007-01-01

    Eye-blink conditioning involves the pairing of a conditioned stimulus (usually a tone) to an unconditioned stimulus (air puff), and it is well established that an intact cerebellum and interpositus nucleus, in particular, are required for this form of classical conditioning. Changes in synaptic number or structure have long been proposed as a…

  12. Eye-Blink Conditioning Is Associated with Changes in Synaptic Ultrastructure in the Rabbit Interpositus Nuclei

    ERIC Educational Resources Information Center

    Weeks, Andrew C. W.; Connor, Steve; Hinchcliff, Richard; LeBoutillier, Janelle C.; Thompson, Richard F.; Petit, Ted L.

    2007-01-01

    Eye-blink conditioning involves the pairing of a conditioned stimulus (usually a tone) to an unconditioned stimulus (air puff), and it is well established that an intact cerebellum and interpositus nucleus, in particular, are required for this form of classical conditioning. Changes in synaptic number or structure have long been proposed as a…

  13. Pontine Stimulation Overcomes Developmental Limitations in the Neural Mechanisms of Eyeblink Conditioning

    ERIC Educational Resources Information Center

    Freeman, John H., Jr; Rabinak, Christine A.; Campolattaro, Matthew M.

    2005-01-01

    Pontine neuronal activation during auditory stimuli increases ontogenetically between postnatal days (P) P17 and P24 in rats. Pontine neurons are an essential component of the conditioned stimulus (CS) pathway for eyeblink conditioning, providing mossy fiber input to the cerebellum. Here we examined whether the developmental limitation in pontine…

  14. The Role of Contingency Awareness in Single-Cue Human Eyeblink Conditioning

    ERIC Educational Resources Information Center

    Weidemann, Gabrielle; Best, Erin; Lee, Jessica C; Lovibond, Peter F.

    2013-01-01

    Single-cue delay eyeblink conditioning is presented as a prototypical example of automatic, nonsymbolic learning that is carried out by subcortical circuits. However, it has been difficult to assess the role of cognition in single-cue conditioning because participants become aware of the simple stimulus contingency so quickly. In this experiment…

  15. Both trace and delay conditioned eyeblink responding can be dissociated from outcome expectancy.

    PubMed

    Weidemann, Gabrielle; Broderick, Joshua; Lovibond, Peter F; Mitchell, Christopher J

    2012-01-01

    Squire and colleagues have proposed that trace and delay eyeblink conditioning are fundamentally different kinds of learning: trace conditioning requires acquisition of a conscious declarative memory for the stimulus contingencies whereas delay conditioning does not. Declarative memory in trace conditioning is thought to generate conditioned responding through the activation of a conscious expectancy for when the unconditioned stimulus (US) is going to occur. Perruchet (1985) has previously shown that in a 50% partial reinforcement design it is possible to dissociate single cue delay eyeblink conditioning from conscious expectancy for the US by examining performance over runs of reinforced and nonreinforced trials. Clark, Manns, and Squire (2001) claim that this dissociation does not occur in trace eyeblink conditioning. In the present experiment we examined the Perruchet effect for short, moderate, and long trace intervals (600, 1000, and 1400 ms) and for the equivalent interstimulus intervals (ISIs) in a delay conditioning procedure. We found evidence for a dissociation of eyeblink CRs and US expectancy over runs regardless of whether there was a delay or a trace arrangement of cues. The reasons for the Perruchet effect are still unclear, but the present data suggest that it does not depend on a separate nondeclarative system of the type proposed by Squire and colleagues. (c) 2012 APA, all rights reserved.

  16. The Role of Contingency Awareness in Single-Cue Human Eyeblink Conditioning

    ERIC Educational Resources Information Center

    Weidemann, Gabrielle; Best, Erin; Lee, Jessica C; Lovibond, Peter F.

    2013-01-01

    Single-cue delay eyeblink conditioning is presented as a prototypical example of automatic, nonsymbolic learning that is carried out by subcortical circuits. However, it has been difficult to assess the role of cognition in single-cue conditioning because participants become aware of the simple stimulus contingency so quickly. In this experiment…

  17. Pretrial Hippocampal ?-State Differentiates Single-Unit Response Profiles during Rabbit Trace Eyeblink Conditioning

    ERIC Educational Resources Information Center

    Cicchese, Joseph J.; Darling, Ryan D.; Berry, Stephen D.

    2015-01-01

    Eyeblink conditioning given in the explicit presence of hippocampal ? results in accelerated learning and enhanced multiple-unit responses, with slower learning and suppression of unit activity under non-? conditions. Recordings from putative pyramidal cells during ?-contingent training show that pretrial ?-state is linked to the probability of…

  18. Medial Auditory Thalamus Inactivation Prevents Acquisition and Retention of Eyeblink Conditioning

    ERIC Educational Resources Information Center

    Halverson, Hunter E.; Poremba, Amy; Freeman, John H.

    2008-01-01

    The auditory conditioned stimulus (CS) pathway that is necessary for delay eyeblink conditioning was investigated using reversible inactivation of the medial auditory thalamic nuclei (MATN) consisting of the medial division of the medial geniculate (MGm), suprageniculate (SG), and posterior intralaminar nucleus (PIN). Rats were given saline or…

  19. Pretrial Hippocampal ?-State Differentiates Single-Unit Response Profiles during Rabbit Trace Eyeblink Conditioning

    ERIC Educational Resources Information Center

    Cicchese, Joseph J.; Darling, Ryan D.; Berry, Stephen D.

    2015-01-01

    Eyeblink conditioning given in the explicit presence of hippocampal ? results in accelerated learning and enhanced multiple-unit responses, with slower learning and suppression of unit activity under non-? conditions. Recordings from putative pyramidal cells during ?-contingent training show that pretrial ?-state is linked to the probability of…

  20. Associative Plasticity in the Medial Auditory Thalamus and Cerebellar Interpositus Nucleus During Eyeblink Conditioning

    PubMed Central

    Halverson, Hunter E.; Lee, Inah; Freeman, John H.

    2010-01-01

    Eyeblink conditioning, a type of associative motor learning, requires the cerebellum. The medial auditory thalamus is a necessary source of stimulus input to the cerebellum during auditory eyeblink conditioning. Nothing is currently known about interactions between the thalamus and cerebellum during associative learning. In the current study, neuronal activity was recorded in the cerebellar interpositus nucleus and medial auditory thalamus simultaneously from multiple tetrodes during auditory eyeblink conditioning to examine the relative timing of learning-related plasticity within these interconnected areas. Learning-related changes in neuronal activity correlated with the eyeblink conditioned response were evident in the cerebellum before the medial auditory thalamus over the course of training and within conditioning trials, suggesting that thalamic plasticity may be driven by cerebellar feedback. Short-latency plasticity developed in the thalamus during the first conditioning session and may reflect attention to the conditioned stimulus. Extinction training resulted in a decrease in learning-related activity in both structures and an increase in inhibition within the cerebellum. A feedback projection from the cerebellar nuclei to the medial auditory thalamus was identified, which may play a role in learning by facilitating stimulus input to the cerebellum via the thalamo-pontine projection. PMID:20592200

  1. Trace Eyeblink Conditioning Requires the Hippocampus but Not Autophosphorylation of [alpha]CaMKII in Mice

    ERIC Educational Resources Information Center

    Ohno, Masuo; Tseng, Wilbur; Silva, Alcino J.; Disterhoft, John F.

    2005-01-01

    Little is known about signaling mechanisms underlying temporal associative learning. Here, we show that mice with a targeted point mutation that prevents autophosphorylation of [alpha]CaMKII ([alpha]CaMKII[superscript T286A]) learn trace eyeblink conditioning normally. This forms a sharp contrast to the severely impaired spatial learning in the…

  2. Pretrial Functional Connectivity Differentiates Behavioral Outcomes during Trace Eyeblink Conditioning in the Rabbit

    ERIC Educational Resources Information Center

    Schroeder, Matthew P.; Weiss, Craig; Procissi, Daniel; Wang, Lei; Disterhoft, John F.

    2016-01-01

    Fluctuations in neural activity can produce states that facilitate and accelerate task-related performance. Acquisition of trace eyeblink conditioning (tEBC) in the rabbit is enhanced when trials are contingent on optimal pretrial activity in the hippocampus. Other regions which are essential for whisker-signaled tEBC, such as the cerebellar…

  3. Perirhinal and Postrhinal, but Not Lateral Entorhinal, Cortices Are Essential for Acquisition of Trace Eyeblink Conditioning

    ERIC Educational Resources Information Center

    Suter, Eugenie E.; Weiss, Craig; Disterhoft, John F.

    2013-01-01

    The acquisition of temporal associative tasks such as trace eyeblink conditioning is hippocampus-dependent, while consolidated performance is not. The parahippocampal region mediates much of the input and output of the hippocampus, and perirhinal (PER) and entorhinal (EC) cortices support persistent spiking, a possible mediator of temporal…

  4. Purkinje Cell Activity in the Cerebellar Anterior Lobe after Rabbit Eyeblink Conditioning

    ERIC Educational Resources Information Center

    Green, John T.; Steinmetz, Joseph E.

    2005-01-01

    The cerebellar anterior lobe may play a critical role in the execution and proper timing of learned responses. The current study was designed to monitor Purkinje cell activity in the rabbit cerebellar anterior lobe after eyeblink conditioning, and to assess whether Purkinje cells in recording locations may project to the interpositus nucleus.…

  5. Pretrial Functional Connectivity Differentiates Behavioral Outcomes during Trace Eyeblink Conditioning in the Rabbit

    ERIC Educational Resources Information Center

    Schroeder, Matthew P.; Weiss, Craig; Procissi, Daniel; Wang, Lei; Disterhoft, John F.

    2016-01-01

    Fluctuations in neural activity can produce states that facilitate and accelerate task-related performance. Acquisition of trace eyeblink conditioning (tEBC) in the rabbit is enhanced when trials are contingent on optimal pretrial activity in the hippocampus. Other regions which are essential for whisker-signaled tEBC, such as the cerebellar…

  6. Cholinergic Septo-Hippocampal Innervation Is Required for Trace Eyeblink Classical Conditioning

    ERIC Educational Resources Information Center

    Fontan-Lozano, Angela; Troncoso, Julieta; Munera, Alejandro; Carrion, Angel Manuel; Delgado-Garcia, Jose Maria

    2005-01-01

    We studied the effects of a selective lesion in rats, with 192-IgG-saporin, of the cholinergic neurons located in the medial septum/diagonal band (MSDB) complex on the acquisition of classical and instrumental conditioning paradigms. The MSDB lesion induced a marked deficit in the acquisition, but not in the retrieval, of eyeblink classical…

  7. Purkinje Cell Activity in the Cerebellar Anterior Lobe after Rabbit Eyeblink Conditioning

    ERIC Educational Resources Information Center

    Green, John T.; Steinmetz, Joseph E.

    2005-01-01

    The cerebellar anterior lobe may play a critical role in the execution and proper timing of learned responses. The current study was designed to monitor Purkinje cell activity in the rabbit cerebellar anterior lobe after eyeblink conditioning, and to assess whether Purkinje cells in recording locations may project to the interpositus nucleus.…

  8. Simultaneous Training on Two Hippocampus-Dependent Tasks Facilitates Acquisition of Trace Eyeblink Conditioning

    ERIC Educational Resources Information Center

    Lee, Grace; Disterhoft, John F.; Kuo, Amy G.

    2006-01-01

    A common cellular alteration, reduced post-burst afterhyperpolarization (AHP) in CA1 neurons, is associated with acquisition of the hippocampus-dependent tasks trace eyeblink conditioning and the Morris water maze. As a similar increase in excitability is correlated with these two learning paradigms, we sought to determine the interactive…

  9. Medial Auditory Thalamus Is Necessary for Acquisition and Retention of Eyeblink Conditioning to Cochlear Nucleus Stimulation

    ERIC Educational Resources Information Center

    Halverson, Hunter E.; Poremba, Amy; Freeman, John H.

    2015-01-01

    Associative learning tasks commonly involve an auditory stimulus, which must be projected through the auditory system to the sites of memory induction for learning to occur. The cochlear nucleus (CN) projection to the pontine nuclei has been posited as the necessary auditory pathway for cerebellar learning, including eyeblink conditioning.…

  10. Perirhinal and Postrhinal, but Not Lateral Entorhinal, Cortices Are Essential for Acquisition of Trace Eyeblink Conditioning

    ERIC Educational Resources Information Center

    Suter, Eugenie E.; Weiss, Craig; Disterhoft, John F.

    2013-01-01

    The acquisition of temporal associative tasks such as trace eyeblink conditioning is hippocampus-dependent, while consolidated performance is not. The parahippocampal region mediates much of the input and output of the hippocampus, and perirhinal (PER) and entorhinal (EC) cortices support persistent spiking, a possible mediator of temporal…

  11. Cholinergic Septo-Hippocampal Innervation Is Required for Trace Eyeblink Classical Conditioning

    ERIC Educational Resources Information Center

    Fontan-Lozano, Angela; Troncoso, Julieta; Munera, Alejandro; Carrion, Angel Manuel; Delgado-Garcia, Jose Maria

    2005-01-01

    We studied the effects of a selective lesion in rats, with 192-IgG-saporin, of the cholinergic neurons located in the medial septum/diagonal band (MSDB) complex on the acquisition of classical and instrumental conditioning paradigms. The MSDB lesion induced a marked deficit in the acquisition, but not in the retrieval, of eyeblink classical…

  12. Simultaneous Training on Two Hippocampus-Dependent Tasks Facilitates Acquisition of Trace Eyeblink Conditioning

    ERIC Educational Resources Information Center

    Lee, Grace; Disterhoft, John F.; Kuo, Amy G.

    2006-01-01

    A common cellular alteration, reduced post-burst afterhyperpolarization (AHP) in CA1 neurons, is associated with acquisition of the hippocampus-dependent tasks trace eyeblink conditioning and the Morris water maze. As a similar increase in excitability is correlated with these two learning paradigms, we sought to determine the interactive…

  13. Medial Auditory Thalamus Is Necessary for Acquisition and Retention of Eyeblink Conditioning to Cochlear Nucleus Stimulation

    ERIC Educational Resources Information Center

    Halverson, Hunter E.; Poremba, Amy; Freeman, John H.

    2015-01-01

    Associative learning tasks commonly involve an auditory stimulus, which must be projected through the auditory system to the sites of memory induction for learning to occur. The cochlear nucleus (CN) projection to the pontine nuclei has been posited as the necessary auditory pathway for cerebellar learning, including eyeblink conditioning.…

  14. Spontaneous Recovery But Not Reinstatement of the Extinguished Conditioned Eyeblink Response in the Rat

    PubMed Central

    Thanellou, Alexandra; Green, John T.

    2011-01-01

    Reinstatement, the return of an extinguished conditioned response (CR) after reexposure to the unconditioned stimulus (US), and spontaneous recovery, the return of an extinguished CR with the passage of time, are two of four well-established phenomena which demonstrate that extinction does not erase the conditioned stimulus (CS)-US association. However, reinstatement of extinguished eyeblink CRs has never been demonstrated and spontaneous recovery of extinguished eyeblink CRs has not been systematically demonstrated in rodent eyeblink conditioning. In Experiment 1, US reexposure was administered 24 hours prior to a reinstatement test. In Experiment 2, US reexposure was administered 5 min prior to a reinstatement test. In Experiment 3, a long, discrete cue (a houselight), present in all phases of training and testing, served as a context within which each trial occurred to maximize context processing, which in other preparations has been shown to be required for reinstatement. In Experiment 4, an additional group was included that received footshock exposure, rather than US reexposure, between extinction and test, and contextual freezing was measured prior to test. Spontaneous recovery was robust in Experiments 3 and 4. In Experiment 4, context freezing was strong in a group given footshock exposure but not in a group given eyeshock US reexposure. There was no reinstatement observed in any experiment. With stimulus conditions that produce eyeblink conditioning and research designs that produce reinstatement in other forms of classical conditioning, we observed spontaneous recovery but not reinstatement of extinguished eyeblink CRs. This suggests that reinstatement, but not spontaneous recovery, is a preparation- or substrate-dependent phenomenon. PMID:21517145

  15. Hippocampal and Cerebellar Single-Unit Activity During Delay and Trace Eyeblink Conditioning in the Rat

    PubMed Central

    Green, John T.; Arenos, Jeremy D.

    2007-01-01

    In delay eyeblink conditioning, the CS overlaps with the US and only a brainstem-cerebellar circuit is necessary for learning. In trace eyeblink conditioning, the CS ends before the US is delivered and several forebrain structures, including the hippocampus, are required for learning, in addition to a brainstem-cerebellar circuit. The interstimulus interval (ISI) between CS onset and US onset is perhaps the most important factor in classical conditioning, but studies comparing delay and trace conditioning have typically not matched these procedures in this crucial factor, so it is often difficult to determine whether results are due to differences between delay and trace or to differences in ISI. In the current study, we employed a 580-ms CS-US interval for both delay and trace conditioning and compared hippocampal CA1 activity and cerebellar interpositus nucleus activity in order to determine whether a unique signature of trace conditioning exists in patterns of single-unit activity in either structure. Long-Evans rats were chronically implanted in either CA1 or interpositus with microwire electrodes and underwent either delay eyeblink conditioning, or trace eyeblink conditioning with a 300-ms trace period between CS offset and US onset. On trials with a CR in delay conditioning, CA1 pyramidal cells showed increases in activation (relative to a pre-CS baseline) during the CS-US period in sessions 1-4 that was attenuated by sessions 5-6. In contrast, on trials with a CR in trace conditioning, CA1 pyramidal cells did not show increases in activation during the CS-US period until sessions 5-6. In sessions 5-6, increases in activation were present only to the CS and not during the trace period. For rats with interpositus electrodes, activation of interpositus neurons on CR trials was present in all sessions in both delay and trace conditioning. However, activation was greater in trace compared to delay conditioning in the first half of the CS-US interval (during the

  16. Amygdalar unit activity during three learning tasks: eyeblink classical conditioning, Pavlovian fear conditioning, and signaled avoidance conditioning.

    PubMed

    Rorick-Kehn, Linda M; Steinmetz, Joseph E

    2005-10-01

    Neural activity in central and basolateral amygdala nuclei (CeA and BLA, respectively) was recorded during delay eyeblink conditioning, Pavlovian fear conditioning, and signaled barpress avoidance. During paired training, the CeA exhibited robust learning-related excitatory activity during all 3 tasks. By contrast, the BLA exhibited minimal activity during eyeblink conditioning, while demonstrating pronounced increases in learning-related excitatory responsiveness during fear conditioning and barpress avoidance. In addition, the relative amount of amygdalar activation observed appeared to be related to the relative intensity of the unconditioned stimulus and somatic requirements of the task. Results suggest the CeA mediates the Pavlovian association between sensory stimuli and the BLA mediates the modulation of instrumental responding through the assignment of motivational value to the unconditioned stimulus.

  17. Hippocampal theta phase-contingent memory retrieval in delay and trace eyeblink conditioning.

    PubMed

    Waselius, Tomi; Pöllänen, Eveliina; Wikgren, Jan; Penttonen, Markku; Nokia, Miriam S

    2017-09-04

    Hippocampal theta oscillations (3-12Hz) play a prominent role in learning. It has been suggested that encoding and retrieval of memories are supported by different phases of the theta cycle. Our previous study on trace eyeblink conditioning in rabbits suggests that the timing of the conditioned stimulus (CS) in relation to theta phase affects encoding but not retrieval of the memory trace. Here, we directly tested the effects of hippocampal theta phase on memory retrieval in two experiments conducted on adult female New Zealand White rabbits. In Experiment 1, animals were trained in trace eyeblink conditioning followed by extinction, and memory retrieval was tested by presenting the CS at troughs and peaks of the theta cycle during different stages of learning. In Experiment 2, animals were trained in delay conditioning either contingent on a high level of theta or at a random neural state. Conditioning was then followed by extinction conducted either at a random state, contingent on theta trough or contingent on theta peak. Our current results indicate that the phase of theta at CS onset has no effect on the performance of the behavioral learned response at any stage of classical eyeblink conditioning or extinction. In addition, theta-contingent trial presentation does not improve learning during delay eyeblink conditioning. The results are consistent with our earlier findings and suggest that the theta phase alone is not sufficient to affect learning at the behavioral level. It seems that the retrieval of recently acquired memories and consequently performing a learned response is moderated by neural mechanisms other than hippocampal theta. Copyright © 2017 Elsevier B.V. All rights reserved.

  18. Eye-blink conditioning is associated with changes in synaptic ultrastructure in the rabbit interpositus nuclei

    PubMed Central

    Weeks, Andrew C.W.; Connor, Steve; Hinchcliff, Richard; LeBoutillier, Janelle C.; Thompson, Richard F.; Petit, Ted L.

    2007-01-01

    Eye-blink conditioning involves the pairing of a conditioned stimulus (usually a tone) to an unconditioned stimulus (air puff), and it is well established that an intact cerebellum and interpositus nucleus, in particular, are required for this form of classical conditioning. Changes in synaptic number or structure have long been proposed as a mechanism that may underlie learning and memory, but localizing these changes has been difficult. Thus, the current experiment took advantage of the large amount of research conducted on the neural circuitry that supports eye-blink conditioning by examining synaptic changes in the rabbit interpositus nucleus. Synaptic quantifications included total number of synapses per neuron, numbers of excitatory versus inhibitory synapses, synaptic curvature, synaptic perforations, and the maximum length of the synapses. No overall changes in synaptic number, shape, or perforations were observed. There was, however, a significant increase in the length of excitatory synapses in the conditioned animals. This increase in synaptic length was particularly evident in the concave-shaped synapses. These results, together with previous findings, begin to describe a sequence of synaptic change in the interpositus nuclei following eye-blink conditioning that would appear to begin with structural change and end with an increase in synaptic number. PMID:17551096

  19. Prefrontal Single-Neuron Responses after Changes in Task Contingencies during Trace Eyeblink Conditioning in Rabbits

    PubMed Central

    2016-01-01

    Abstract A number of studies indicate that the medial prefrontal cortex (mPFC) plays a role in mediating the expression of behavioral responses during tasks that require flexible changes in behavior. During trace eyeblink conditioning, evidence suggests that the mPFC provides the cerebellum with a persistent input to bridge the temporal gap between conditioned and unconditioned stimuli. Therefore, the mPFC is in a position to directly mediate the expression of trace conditioned responses. However, it is unknown whether persistent neural responses are associated with the flexible expression of behavior when task contingencies are changed during trace eyeblink conditioning. To investigate this, single-unit activity was recorded in the mPFC of rabbits during extinction and reacquisition of trace eyeblink conditioning, and during training to a different conditional stimulus. Persistent responses remained unchanged after full extinction, and also did not change during reacquisition training. During training to a different tone, however, the generalization of persistent responses to the new stimulus was associated with an animal’s performance—when persistent responses generalized to the new tone, performance was high (>50% response rate). When persistent responses decreased to baseline rates, performance was poor (<50% response rate). The data suggest that persistent mPFC responses do not appear to mediate flexible changes in the expression of the original learning, but do appear to play a role in the generalization of that learning when the task is modified. PMID:27517083

  20. Eye-blink conditioning is associated with changes in synaptic ultrastructure in the rabbit interpositus nuclei.

    PubMed

    Weeks, Andrew C W; Connor, Steve; Hinchcliff, Richard; LeBoutillier, Janelle C; Thompson, Richard F; Petit, Ted L

    2007-06-01

    Eye-blink conditioning involves the pairing of a conditioned stimulus (usually a tone) to an unconditioned stimulus (air puff), and it is well established that an intact cerebellum and interpositus nucleus, in particular, are required for this form of classical conditioning. Changes in synaptic number or structure have long been proposed as a mechanism that may underlie learning and memory, but localizing these changes has been difficult. Thus, the current experiment took advantage of the large amount of research conducted on the neural circuitry that supports eye-blink conditioning by examining synaptic changes in the rabbit interpositus nucleus. Synaptic quantifications included total number of synapses per neuron, numbers of excitatory versus inhibitory synapses, synaptic curvature, synaptic perforations, and the maximum length of the synapses. No overall changes in synaptic number, shape, or perforations were observed. There was, however, a significant increase in the length of excitatory synapses in the conditioned animals. This increase in synaptic length was particularly evident in the concave-shaped synapses. These results, together with previous findings, begin to describe a sequence of synaptic change in the interpositus nuclei following eye-blink conditioning that would appear to begin with structural change and end with an increase in synaptic number.

  1. Prefrontal Single-Neuron Responses after Changes in Task Contingencies during Trace Eyeblink Conditioning in Rabbits.

    PubMed

    Siegel, Jennifer J

    2016-01-01

    A number of studies indicate that the medial prefrontal cortex (mPFC) plays a role in mediating the expression of behavioral responses during tasks that require flexible changes in behavior. During trace eyeblink conditioning, evidence suggests that the mPFC provides the cerebellum with a persistent input to bridge the temporal gap between conditioned and unconditioned stimuli. Therefore, the mPFC is in a position to directly mediate the expression of trace conditioned responses. However, it is unknown whether persistent neural responses are associated with the flexible expression of behavior when task contingencies are changed during trace eyeblink conditioning. To investigate this, single-unit activity was recorded in the mPFC of rabbits during extinction and reacquisition of trace eyeblink conditioning, and during training to a different conditional stimulus. Persistent responses remained unchanged after full extinction, and also did not change during reacquisition training. During training to a different tone, however, the generalization of persistent responses to the new stimulus was associated with an animal's performance-when persistent responses generalized to the new tone, performance was high (>50% response rate). When persistent responses decreased to baseline rates, performance was poor (<50% response rate). The data suggest that persistent mPFC responses do not appear to mediate flexible changes in the expression of the original learning, but do appear to play a role in the generalization of that learning when the task is modified.

  2. Shortened Conditioned Eyeblink Response Latency in Male but not Female Wistar-Kyoto Hyperactive Rats

    PubMed Central

    Thanellou, Alexandra; Schachinger, Kira M.; Green, John T.

    2014-01-01

    Reductions in the volume of the cerebellum and impairments in cerebellar-dependent eyeblink conditioning have been observed in attention-deficit/hyperactivity disorder (ADHD). Recently, it was reported that subjects with ADHD as well as male spontaneously hypertensive rats (SHR), a strain that is frequently employed as an animal model in the study of ADHD, exhibit a parallel pattern of timing deficits in eyeblink conditioning. One criticism that has been posed regarding the validity of the SHR strain as an animal model for the study of ADHD is that SHRs are not only hyperactive but also hypertensive. It is conceivable that many of the behavioral characteristics seen in SHRs that seem to parallel the behavioral symptoms of ADHD are not solely due to hyperactivity but instead are the net outcome of the interaction between hyperactivity and hypertension. We used Wistar-Kyoto Hyperactive (WKHA) and Wistar-Kyoto Hypertensive (WKHT) rats (males and females), strains generated from recombinant inbreeding of SHRs and their progenitor strain, Wistar-Kyoto (WKY) rats, to compare eyeblink conditioning in strains that are exclusively hyperactive or hypertensive. We used a long-delay eyeblink conditioning task in which a tone conditioned stimulus was paired with a periorbital stimulation unconditioned stimulus (750-ms delay paradigm). Our results showed that WKHA and WKHT rats exhibited similar rates of conditioned response (CR) acquisition. However, WKHA males displayed shortened CR latencies (early onset and peak latency) in comparison to WKHT males. In contrast, female WKHAs and WKHTs did not differ. In subsequent extinction training, WKHA rats extinguished at similar rates in comparison to WKHT rats. The current results support the hypothesis of a relationship between cerebellar abnormalities and ADHD in an animal model of ADHD-like symptoms that does not also exhibit hypertension, and suggest that cerebellar-related timing deficits are specific to males. PMID:19485572

  3. Modeling possible effects of atypical cerebellar processing on eyeblink conditioning in autism.

    PubMed

    Radell, Milen L; Mercado, Eduardo

    2014-09-01

    Autism is unique among other disorders in that acquisition of conditioned eyeblink responses is enhanced in children, occurring in a fraction of the trials required for control participants. The timing of learned responses is, however, atypical. Two animal models of autism display a similar phenotype. Researchers have hypothesized that these differences in conditioning reflect cerebellar abnormalities. The present study used computer simulations of the cerebellar cortex, including inhibition by the molecular layer interneurons, to more closely examine whether atypical cerebellar processing can account for faster conditioning in individuals with autism. In particular, the effects of inhibitory levels on delay eyeblink conditioning were simulated, as were the effects of learning-related synaptic changes at either parallel fibers or ascending branch synapses from granule cells to Purkinje cells. Results from these simulations predict that whether molecular layer inhibition results in an enhancement or an impairment of acquisition, or changes in timing, may depend on (1) the sources of inhibition, (2) the levels of inhibition, and (3) the locations of learning-related changes (parallel vs. ascending branch synapses). Overall, the simulations predict that a disruption in the balance or an overall increase of inhibition within the cerebellar cortex may contribute to atypical eyeblink conditioning in children with autism and in animal models of autism.

  4. I Think, Therefore Eyeblink: The Importance of Contingency Awareness in Conditioning.

    PubMed

    Weidemann, Gabrielle; Satkunarajah, Michelle; Lovibond, Peter F

    2016-04-01

    Can conditioning occur without conscious awareness of the contingency between the stimuli? We trained participants on two separate reaction time tasks that ensured attention to the experimental stimuli. The tasks were then interleaved to create a differential Pavlovian contingency between visual stimuli from one task and an airpuff stimulus from the other. Many participants were unaware of the contingency and failed to show differential eyeblink conditioning, despite attending to a salient stimulus that was contingently and contiguously related to the airpuff stimulus over many trials. Manipulation of awareness by verbal instruction dramatically increased awareness and differential eyeblink responding. These findings cast doubt on dual-system theories, which propose an automatic associative system independent of cognition, and provide strong evidence that cognitive processes associated with awareness play a causal role in learning.

  5. Metabolic mapping of the rat cerebellum during delay and trace eyeblink conditioning

    PubMed Central

    Plakke, Bethany; Freeman, John H.; Poremba, Amy

    2008-01-01

    The essential neural circuitry for delay eyeblink conditioning has been largely identified, whereas much of the neural circuitry for trace conditioning has not been identified. The major difference between delay and trace conditioning is a time gap between the presentation of the conditioned stimulus (CS) and the unconditioned stimulus (US) during trace conditioning. It is this time gap or trace interval which accounts for an additional memory component in trace conditioning. Additional neural structures are also necessary for trace conditioning, including hippocampus and prefrontal cortex. This addition of forebrain structures necessary for trace but not delay conditioning suggests other brain areas become involved when a memory gap is added to the conditioning parameters. A metabolic marker of energy use, radioactively labeled glucose analog, was used to compare differences in glucose analog uptake between delay, trace, and unpaired experimental groups in order to identify new areas of involvement within the cerebellum. Known structures such as the interpositus nucleus and lobule HVI showed increased activation for both delay and trace conditioning compared to unpaired conditioning. However, there was a differential amount of activation between anterior and posterior portions of the interpositus nucleus between delay and trace, respectively. Cerebellar cortical areas including lobules IV and V of anterior lobe, Crus I, Crus II, and paramedian lobule also showed increases in activity for delay conditioning but not for trace conditioning. Delay and trace eyeblink conditioning both resulted in increased metabolic activity within the cerebellum but delay conditioning resulted in more widespread cerebellar cortical activation. PMID:17468019

  6. Purkinje cell activity in the cerebellar anterior lobe after rabbit eyeblink conditioning

    PubMed Central

    Green, John T.; Steinmetz, Joseph E.

    2005-01-01

    The cerebellar anterior lobe may play a critical role in the execution and proper timing of learned responses. The current study was designed to monitor Purkinje cell activity in the rabbit cerebellar anterior lobe after eyeblink conditioning, and to assess whether Purkinje cells in recording locations may project to the interpositus nucleus. Rabbits were trained in an interstimulus interval discrimination procedure in which one tone signaled a 250-msec conditioned stimulus-unconditioned stimulus (CS-US) interval and a second tone signaled a 750-msec CS-US interval. All rabbits showed conditioned responses to each CS with mean onset and peak latencies that coincided with the CS-US interval. Many anterior lobe Purkinje cells showed significant learning-related activity after eyeblink conditioning to one or both of the CSs. More Purkinje cells responded with inhibition than with excitation to CS presentation. In addition, when the firing patterns of all conditioning-related Purkinje cells were pooled, it appeared that the population showed a pattern of excitation followed by inhibition during the CS-US interval. Using cholera toxin-conjugated horseradish peroxidase, Purkinje cells in recording areas were found to project to the interpositus nucleus. These data support previous studies that have suggested a role for the anterior cerebellar cortex in eyeblink conditioning as well as models of cerebellar-mediated CR timing that postulate that Purkinje cell activity inhibits conditioned response (CR) generation during the early portion of a trial by inhibiting the deep cerebellar nuclei and permits CR generation during the later portion of a trial through disinhibition of the cerebellar nuclei. PMID:15897252

  7. Phase-locked hippocampal theta-band responses are related to discriminative eyeblink conditioned responding.

    PubMed

    Nokia, Miriam S; Wikgren, Jan

    2013-11-01

    Hippocampal electrophysiological oscillatory activity is undoubtedly related to learning and memory. The relative power of spontaneously occurring hippocampal theta (∼4-8 Hz) oscillations predicts how fast and how well an animal will learn: more theta predicts faster acquisition of the conditioned response in eyeblink conditioning in both rats and rabbits. Here, our aim was to study how hippocampal theta-band responses to conditioned stimuli elicited during very-long delay discrimination eyeblink conditioning relate to the accompanying conditioned behavior. We trained adult male New Zealand White rabbits using 1500-ms auditory stimuli as conditioned stimuli and a 100-ms airpuff as an unconditioned stimulus. The reinforced conditioned stimulus overlapped and co-terminated with the unconditioned stimulus whereas the non-reinforced conditioned stimulus was always presented alone. Consistent with previous results, hippocampal theta-band responses to the conditioned stimuli diminished in amplitude across training. Interestingly, hippocampal theta-band responses were most consistently time-locked when a well-trained animal failed to suppress behavioral learned responses to the non-reinforced conditioned stimulus. We suggest that phase-locking of hippocampal theta-band oscillations in response to external stimuli reflects retrieval of the dominant memory trace (adaptive or not) along with initiating the most prominent action scheme related to that memory trace.

  8. Central amygdala lesions inhibit pontine nuclei acoustic reactivity and retard delay eyeblink conditioning acquisition in adult rats.

    PubMed

    Pochiro, Joseph M; Lindquist, Derick H

    2016-06-01

    In delay eyeblink conditioning (EBC) a neutral conditioned stimulus (CS; tone) is repeatedly paired with a mildly aversive unconditioned stimulus (US; periorbital electrical shock). Over training, subjects learn to produce an anticipatory eyeblink conditioned response (CR) during the CS, prior to US onset. While cerebellar synaptic plasticity is necessary for successful EBC, the amygdala is proposed to enhance eyeblink CR acquisition. In the current study, adult Long-Evans rats received bilateral sham or neurotoxic lesions of the central nucleus of the amygdala (CEA) followed by 1 or 4 EBC sessions. Fear-evoked freezing behavior, CS-mediated enhancement of the unconditioned response (UR), and eyeblink CR acquisition were all impaired in the CEA lesion rats relative to sham controls. There were also significantly fewer c-Fos immunoreactive cells in the pontine nuclei (PN)-major relays of acoustic information to the cerebellum-following the first and fourth EBC session in lesion rats. In sham rats, freezing behavior decreased from session 1 to 4, commensurate with nucleus-specific reductions in amygdala Fos+ cell counts. Results suggest delay EBC proceeds through three stages: in stage one the amygdala rapidly excites diffuse fear responses and PN acoustic reactivity, facilitating cerebellar synaptic plasticity and the development of eyeblink CRs in stage two, leading, in stage three, to a diminution or stabilization of conditioned fear responding.

  9. Effect of transcranial direct current stimulation on semantic discrimination eyeblink conditioning.

    PubMed

    Kotilainen, Tuukka; Lehto, Soili M; Wikgren, Jan

    2015-10-01

    Transcranial direct current stimulation (tDCS) is a neuromodulation method that has been used to modulate learning. We tested whether anodal tDCS targeted at the left DLPFC could enhance learning in a semantic variant of discrimination eyeblink conditioning, i.e., whether the stimulation would have a specific effect on the discrimination ability, rate of acquisition, amplitude of the conditioned response (CR), or all of these. Immediately prior to the eyeblink conditioning, the participants received either active stimulation of 1 mA for 10 min or sham stimulation. The anode was placed over F3 and the cathode over the right supraorbital area. The conditioned stimuli (CSs) were common Finnish male and female names that were presented as text. Male names were reinforced with an unconditioned stimulus. Stimulation had no effect on the learning rate or discrimination ratio, but the stimulated participants showed steeper CR acquisition in the initial phase of the experiment. Nevertheless, the participants in the stimulation group showed greater eyeblink CRs to the non-reinforced CS. Contrary to our initial hypothesis, the magnitude and rate of CRs to non-reinforced CS was higher in the active stimulation group than in the sham stimulation group, which may suggest deterioration of discrimination and contingency awareness in the used task. Our observations may suggest a lack of effect on the participants' ability to discriminate between two different types of CS. Furthermore, cathodal modulation of the right prefrontal cortex may explain the change in magnitude and rate of CRs to non-reinforced CS. Copyright © 2015 Elsevier B.V. All rights reserved.

  10. MK-801 administration during neonatal ethanol withdrawal attenuates interpositus cell loss and juvenile eyeblink conditioning deficits.

    PubMed

    Young, Brandt W; Sengelaub, Dale R; Steinmetz, Joseph E

    2010-06-01

    Binge-level doses of ethanol have been demonstrated to severely disrupt the cerebellum and cerebellum-dependent tasks when administered to rodent subjects during the early postnatal period. N-methyl-d-aspartic acid (NMDA) receptor-mediated excitotoxicity associated with ethanol withdrawal has been implicated as a significant component contributing to neurotoxic effects resulting from early ethanol exposure, and studies using MK-801 (dizocilpine) have reported protection from ethanol-induced damage. The present study examined whether the administration of MK-801 during ethanol withdrawal would ameliorate ethanol-associated cell death in the interpositus nucleus of the cerebellum and behavioral deficits in a cerebellar dependent task. Long Evans rat pups were treated with ethanol (5.25 g/kg) in a binge-like manner on postnatal day 6 using intragastric intubation. Subjects then received an injection of MK-801 (0.5mg/kg) or vehicle during withdrawal, 30h after ethanol exposure. Rats were then trained on an eyeblink classical conditioning task as juveniles (40 days of age), and cerebellar interpositus nucleus numbers were assessed after conditioning. Ethanol-exposed subjects exhibited reductions in neuronal populations and behavioral deficits during eyeblink conditioning. However, MK-801 administration significantly attenuated observed deficiencies, suggesting a protective effect resulting from MK-801 treatment during ethanol withdrawal. These results support the role of NMDA receptor-mediated excitotoxicity as a component mechanism by which ethanol produces teratogenicity. Additionally, our findings support previous reports that have shown correlations between dependent measures of eyeblink classical-conditioning behavior and unbiased cell counts in the interpositus nucleus. 2010 Elsevier Inc. All rights reserved.

  11. Eyeblink conditioning leads to fewer synapses in the rabbit cerebellar cortex.

    PubMed

    Connor, S; Bloomfield, J; LeBoutillier, J C; Thompson, R F; Petit, T L; Weeks, A C W

    2009-08-01

    Eyeblink conditioning involves the pairing of a conditioned stimulus (tone) to an aversive unconditioned stimulus (air puff). Although the circuitry that underlies this form of learning is well defined, synaptic changes in these structures have not been fully investigated. This experiment examined synaptic structural plasticity in the cerebellar cortex, a structure that has been found to modulate the acquisition and timing of the conditioned response. Long-term depression of Purkinje cells (PCs) in the cerebellar cortex has been proposed as a mechanism for releasing inhibition of the interpositus nuclei, a structure critical for the formation of the CR. Adult albino rabbits were randomly allocated to either a paired, unpaired, or exposure-only condition. The results showed a significant decrease in the number of excitatory synapses in the outer layer of the cerebellar cortex in the conditioned rabbits compared with controls. This finding suggests that a reduction in the number of excitatory synapses may contribute to the lasting depression of PC activity that is associated with eyeblink conditioning. 2009 APA, all rights reserved

  12. Facilitated acquisition of standard but not long delay classical eyeblink conditioning in behaviorally inhibited adolescents.

    PubMed

    Caulfield, M D; VanMeenen, K M; Servatius, R J

    2015-02-01

    Adolescence is a key age in the development of anxiety disorders. The present study assessed the relationship between behavioral inhibition, a risk factor for anxiety typified by avoidance, and acquisition of the classically conditioned eyeblink response. 168 healthy high school students (mean age 15.7 years, 54% female) were given a battery of self-report measures including the Adult Measure of Behavioural Inhibition (AMBI). The study compared acquisition of three experimental training conditions. Two groups were given paired CS-US training: standard delay of 500-ms or long delay of 1000-ms with CS overlapping and co-terminating with a 50-ms airpuff US. A third group received unpaired training of 1000-ms CS and 50-ms airpuff US. Inhibited individuals showed greater acquisition of the conditioned eyeblink response in the 500-ms CS condition, but not in the paired 1000-ms condition. No differences in spontaneous blinks or reactivity to the stimulus were evident in the 1000-ms unpaired CS condition. Results support a relationship between associative learning and anxiety vulnerability that may be mediated by cerebellar functioning in inhibited individuals.

  13. Hippocampal theta (3-8Hz) activity during classical eyeblink conditioning in rabbits.

    PubMed

    Nokia, Miriam S; Penttonen, Markku; Korhonen, Tapani; Wikgren, Jan

    2008-07-01

    In 1978, Berry and Thompson showed that the amount of theta (3-8Hz) activity in the spontaneous hippocampal EEG predicted learning rate in subsequent eyeblink conditioning in rabbits. More recently, the absence of theta activity during the training trial has been shown to have a detrimental effect on learning rate. Here, we aimed to further explore the relationship between theta activity and classical eyeblink conditioning by determining how the relative power of hippocampal theta activity [theta/(theta+delta) ratio] changes during both unpaired control and paired training phases. We found that animals with a higher hippocampal theta ratio immediately before conditioning learned faster and also that in these animals the theta ratio was higher throughout both experimental phases. In fact, while the hippocampal theta ratio remained stable in the fast learners as a function of training, it decreased in the slow learners already during unpaired training. In addition, the presence of hippocampal theta activity enhanced the hippocampal model of the conditioned response (CR) and seemed to be beneficial for CR performance in terms of peak latency during conditioning, but did not have any effect when the animals showed asymptotic learning. Together with earlier findings, these results imply that the behavioral state in which hippocampal theta activity is absent is detrimental for learning, and that the behavioral state in which hippocampal theta activity dominates is beneficial for learning, at least before a well-learned state is achieved.

  14. Rabbit classical eyeblink conditioning is altered by brief cerebellar cortical stimulation.

    PubMed

    Katz, D B; Tracy, J A; Steinmetz, J E

    2001-03-01

    A pair of studies examined how cortical intracerebellar stimulation (ICS) affects eyeblink conditioning in the rabbit. Rabbits were implanted with chronic bipolar stimulating electrodes in the cell body layers of cerebellar lobule H-VI. Brief (40 ms) trains of intracranial stimulation (100 Hz, 250 microA) were delivered during training trials [forward pairings of a tone-conditioned stimulus (CS) with an air puff unconditioned stimulus (US)]. In Experiment 1, the onset of ICS varied randomly within sessions. US-onset-coincident ICS proved detrimental to the maintenance of conditioning [measured as the percentage of trials on which conditioned responses (CRs) were made] compared to ICS that ended 60 ms before US onset. Based on these findings, a second experiment compared a group trained with ICS consistently delivered at US onset to groups trained with ICS consistently delivered either at CS onset or between the two stimuli, as well as to unstimulated control subjects. Animals receiving CS- or US-coincident ICS learned slowest, whereas animals receiving middle stimulation learned more quickly than all other groups. In both Experiments 1 and 2, highly trained animals produced blinks in direct response to the stimulation. These data are discussed in terms of a new hypothesis concerning interactions between cerebellar cortex and the deep cerebellar nuclei during eyeblink conditioning--a rebound from inhibition hypothesis.

  15. Eye-blink conditioning deficits indicate temporal processing abnormalities in schizophrenia.

    PubMed

    Bolbecker, Amanda R; Mehta, Crystal S; Edwards, Chad R; Steinmetz, Joseph E; O'Donnell, Brian F; Hetrick, William P

    2009-06-01

    Theoretical models suggest that symptoms of schizophrenia may be due to a dysfunctional modulatory system associated with the cerebellum. Although it has long been known that the cerebellum plays a critical role in associative learning and motor timing, recent evidence suggests that it also plays a role in nonmotor psychological processes. Indeed, cerebellar anomalies in schizophrenia have been linked to cognitive dysfunction and poor long-term outcome. To test the hypothesis that schizophrenia is associated with cerebellar dysfunction, cerebellar-dependent, delay eye-blink conditioning was examined in 62 individuals with schizophrenia and 62 age-matched non-psychiatric comparison subjects. The conditioned stimulus was a 400 ms tone, which co-terminated with a 50 ms unconditioned stimulus air puff. A subset of participants (25 with schizophrenia and 29 controls) also completed the Wechsler Abbreviated Scale of Intelligence. Participants with schizophrenia exhibited lower rates of eye-blink conditioning, including earlier (less adaptively timed) conditioned response latencies. Cognitive functioning was correlated with the rate of conditioned responsing in the non-psychiatric comparison subjects but not among those with schizophrenia, and the magnitude of these correlations significantly differed between groups. These findings are consistent with models of schizophrenia in which disruptions within the cortico-cerebellar-thalamic-cortical (CCTC) brain circuit are postulated to underlie the cognitive fragmentation that characterizes the disorder.

  16. Hippocampal ripple-contingent training accelerates trace eyeblink conditioning and retards extinction in rabbits.

    PubMed

    Nokia, Miriam S; Penttonen, Markku; Wikgren, Jan

    2010-08-25

    There are at least two distinct oscillatory states of the hippocampus that are related to distinct behavioral patterns. Theta (4-12 Hz) oscillation has been suggested to indicate selective attention during which the animal concentrates on some features of the environment while suppressing reactivity to others. In contrast, sharp-wave ripples ( approximately 200 Hz) can be seen in a state in which the hippocampus is at its most responsive to any kind of afferent stimulation. In addition, external stimulation tends to evoke and reset theta oscillation, the phase of which has been shown to modulate synaptic plasticity in the hippocampus. Theoretically, training on a hippocampus-dependent learning task contingent upon ripples could enhance learning rate due to elevated responsiveness and enhanced phase locking of the theta oscillation. We used a brain-computer interface to detect hippocampal ripples in rabbits to deliver trace eyeblink conditioning and extinction trials selectively contingent upon them. A yoked control group was trained regardless of their ongoing neural state. Ripple-contingent training expedited acquisition of the conditioned response early in training and evoked stronger theta-band phase locking to the conditioned stimulus. Surprisingly, ripple-contingent training also resulted in slower extinction in well trained animals. We suggest that the ongoing oscillatory activity in the hippocampus determines the extent to which a stimulus can induce a phase reset of the theta oscillation, which in turn is the determining factor of learning rate in trace eyeblink conditioning.

  17. Extracellular amino acid levels in the interpositus nucleus during classical eyeblink conditioning in alert cats.

    PubMed

    Jiménez-Díaz, Lydia; Gruart, Agnès; Miñano, Francisco Javier; Delgado-García, José María

    2007-10-01

    The extracellular levels of selected amino acids in the cerebellar posterior interpositus nucleus (PIN) during classical eyeblink conditioning was analyzed in alert cats using a delay paradigm. Animals were prepared for the chronic recording of eyelid movements (with the magnetic search-coil technique) and the electromyographic activity of the orbicularis oculi muscle. With the help of a guide and push-pull cannulae, selected PIN sites were perfused daily during classical eyeblink conditioning. The perfusate was sampled at intervals of 5 min and analyzed with a high-pressure liquid chromatography- electrochemical detection (HPLC-EC) method. The analysis of push-pull perfusate revealed a significant increase in the release of glycine, taurine, and glutamate across the successive conditioning sessions, in parallel with the acquisition of eyelid conditioned responses (CRs). Both CRs and extracellular levels of these three amino acids returned to control values during extinction. Other amino acids (alanine, GABA, glutamine, serine, and threonine) did not undergo modifications in their extracellular concentrations across the training. Results are discussed with regard to the role of PIN in this type of associative learning.

  18. Medial auditory thalamus is necessary for acquisition and retention of eyeblink conditioning to cochlear nucleus stimulation.

    PubMed

    Halverson, Hunter E; Poremba, Amy; Freeman, John H

    2015-05-01

    Associative learning tasks commonly involve an auditory stimulus, which must be projected through the auditory system to the sites of memory induction for learning to occur. The cochlear nucleus (CN) projection to the pontine nuclei has been posited as the necessary auditory pathway for cerebellar learning, including eyeblink conditioning. However, the medial auditory thalamic nuclei (MATN), consisting of the medial division of the medial geniculate, suprageniculate, and posterior interlaminar nucleus have also been implicated as a critical auditory relay to the pontine nuclei for cerebellum-dependent motor learning. The MATN also conveys auditory information to the amygdala necessary for avoidance and fear conditioning. The current study used CN stimulation to increase activity in the pontine nuclei, relative to a tone stimulus, and possibly provide sufficient input to the cerebellum for acquisition or retention of eyeblink conditioning during MATN inactivation. Primary and secondary effects of CN stimulation and MATN inactivation were examined using 2-deoxy-glucose autoradiography. Stimulation of CN increased activity in the pontine nuclei, however, this increase was not sufficient for cerebellar learning during MATN inactivation. Results of the current experiment provide additional evidence indicating the MATN may be the critical auditory relay for many associative learning tasks.

  19. Relational and procedural memory systems in the goldfish brain revealed by trace and delay eyeblink-like conditioning.

    PubMed

    Gómez, A; Rodríguez-Expósito, B; Durán, E; Martín-Monzón, I; Broglio, C; Salas, C; Rodríguez, F

    2016-12-01

    The presence of multiple memory systems supported by different neural substrata has been demonstrated in animal and human studies. In mammals, two variants of eyeblink classical conditioning, differing only in the temporal relationships between the conditioned stimulus (CS) and the unconditioned stimulus (US), have been widely used to study the neural substrata of these different memory systems. Delay conditioning, in which both stimuli coincide in time, depends on a non-relational memory system supported by the cerebellum and associated brainstem circuits. In contrast, trace conditioning, in which a stimulus-free time gap separates the CS and the US, requires a declarative or relational memory system, thus depending on forebrain structures in addition to the cerebellum. The distinction between the explicit or relational and the implicit or procedural memory systems that support trace and delay classical conditioning has been extensively studied in mammals, but studies in other vertebrate groups are relatively scarce. In the present experiment we analyzed the differential involvement of the cerebellum and the telencephalon in delay and trace eyeblink-like classical conditioning in goldfish. The results show that whereas the cerebellum lesion prevented the eyeblink-like conditioning in both procedures, the telencephalon ablation impaired exclusively the acquisition of the trace conditioning. These data showing that comparable neural systems support delay and trace eyeblink conditioning in teleost fish and mammals suggest that these separate memory systems and their neural bases could be a shared ancestral brain feature of the vertebrate lineage. Copyright © 2016 Elsevier Inc. All rights reserved.

  20. Stimulation of the Lateral Geniculate, Superior Colliculus, or Visual Cortex is Sufficient for Eyeblink Conditioning in Rats

    ERIC Educational Resources Information Center

    Halverson, Hunter E.; Hubbard, Erin M.; Freeman, John H.

    2009-01-01

    The role of the cerebellum in eyeblink conditioning is well established. Less work has been done to identify the necessary conditioned stimulus (CS) pathways that project sensory information to the cerebellum. A possible visual CS pathway has been hypothesized that consists of parallel inputs to the pontine nuclei from the lateral geniculate…

  1. Stimulation of the Lateral Geniculate, Superior Colliculus, or Visual Cortex is Sufficient for Eyeblink Conditioning in Rats

    ERIC Educational Resources Information Center

    Halverson, Hunter E.; Hubbard, Erin M.; Freeman, John H.

    2009-01-01

    The role of the cerebellum in eyeblink conditioning is well established. Less work has been done to identify the necessary conditioned stimulus (CS) pathways that project sensory information to the cerebellum. A possible visual CS pathway has been hypothesized that consists of parallel inputs to the pontine nuclei from the lateral geniculate…

  2. Dimethoate accelerates the extinction of eyeblink conditioning in mice.

    PubMed

    Valenzuela-Harrington, Mauricio; Castillo, Irene; Díaz, Corín; Alés, Inés; Rodríguez-Moreno, Antonio

    2012-01-01

    In agriculture, organophosphates are frequently used as insecticides and pesticides. These compounds decrease acetylcholine esterase (AChE) activity, thereby provoking an accumulation of the neurotransmitter acetylcholine at synapses and resulting in the over-stimulation of acetylcholine receptors. Using trace paradigms, we investigated the effects of dimethoate, a widely used organophosphate insecticide, on the classical conditioning of eyelid responses, a hippocampal-dependent mouse model of associative learning. Mice were conditioned with a trace shock-SHOCK paradigm having first implanted stimulating electrodes in the supraorbitary nerve and recording electrodes in the ipsilateral orbicularis oculi muscle. When these mice were injected with dimethoate (5, 20, 50mg/kg/day) they were capable of acquiring associative learning, and the latency and amplitude of their unconditioned eyelid responses were unaffected by the administration of the pesticide. However, dimethoate administration led to the rapid extinction of conditioned responses, suggesting that this organophosphate accelerates the extinction of this form of associative learning. Analysis of the motor function of these mice using the rotarod performance test revealed that motor function and performance clearly deteriorated following dimethoate administration, with no improvements over the following 4 days. Together these findings indicate that dimethoate accelerates the extinction of acquired conditioned responses, affecting associative learning and memory, and it impairs motor function and performance in mice.

  3. The role of US recency in the Perruchet effect in eyeblink conditioning.

    PubMed

    Weidemann, Gabrielle; Lovibond, Peter F

    2016-09-01

    In the Perruchet effect, there is a concurrent dissociation between participants' conditioned responses (CRs) and their expectancy of the unconditioned stimulus (US) across runs of repeated trials. The effect has been taken as evidence for multiple learning processes, but this conclusion follows only if the CR trend is the result of learning. Two experiments examined the role of US recency in generating the observed CR trend. A standard Perruchet condition was compared with a control condition in which US recency was controlled by presenting the US on every trial. The associative contribution was maintained by varying the temporal relationship between the CS and the US. In both experiments the pattern of CRs seen in the Perruchet condition was absent in the control condition, suggesting that the eyeblink trend in the Perruchet effect may be due to a non-associative performance factor such as priming or sensitization arising from recent US presentations. Copyright © 2016 Elsevier B.V. All rights reserved.

  4. Prolonging the postcomplex spike pause speeds eyeblink conditioning.

    PubMed

    Maiz, Jaione; Karakossian, Movses H; Pakaprot, Narawut; Robleto, Karla; Thompson, Richard F; Otis, Thomas S

    2012-10-09

    Climbing fiber input to the cerebellum is believed to serve as a teaching signal during associative, cerebellum-dependent forms of motor learning. However, it is not understood how this neural pathway coordinates changes in cerebellar circuitry during learning. Here, we use pharmacological manipulations to prolong the postcomplex spike pause, a component of the climbing fiber signal in Purkinje neurons, and show that these manipulations enhance the rate of learning in classical eyelid conditioning. Our findings elucidate an unappreciated aspect of the climbing fiber teaching signal, and are consistent with a model in which convergent postcomplex spike pauses drive learning-related plasticity in the deep cerebellar nucleus. They also suggest a physiological mechanism that could modulate motor learning rates.

  5. Prolonging the postcomplex spike pause speeds eyeblink conditioning

    PubMed Central

    Maiz, Jaione; Karakossian, Movses H.; Pakaprot, Narawut; Robleto, Karla; Thompson, Richard F.; Otis, Thomas S.

    2012-01-01

    Climbing fiber input to the cerebellum is believed to serve as a teaching signal during associative, cerebellum-dependent forms of motor learning. However, it is not understood how this neural pathway coordinates changes in cerebellar circuitry during learning. Here, we use pharmacological manipulations to prolong the postcomplex spike pause, a component of the climbing fiber signal in Purkinje neurons, and show that these manipulations enhance the rate of learning in classical eyelid conditioning. Our findings elucidate an unappreciated aspect of the climbing fiber teaching signal, and are consistent with a model in which convergent postcomplex spike pauses drive learning-related plasticity in the deep cerebellar nucleus. They also suggest a physiological mechanism that could modulate motor learning rates. PMID:22988089

  6. Effects of Paradigm and Inter-Stimulus Interval on Age Differences in Eyeblink Classical Conditioning in Rabbits

    ERIC Educational Resources Information Center

    Woodruff-Pak, Diana S.; Seta, Susan E.; Roker, LaToya A.; Lehr, Melissa A.

    2007-01-01

    The aim of this study was to examine parameters affecting age differences in eyeblink classical conditioning in a large sample of young and middle-aged rabbits. A total of 122 rabbits of mean ages of 4 or 26 mo were tested at inter-stimulus intervals (ISIs) of 600 or 750 msec in the delay or trace paradigms. Paradigm affected both age groups…

  7. Age-Related Impairment in the 250-Millisecond Delay Eyeblink Classical Conditioning Procedure in C57BL/6 Mice

    PubMed Central

    Vogel, Richard W.; Ewers, Michael; Ross, Charlene; Gould, Thomas J.; Woodruff-Pak, Diana S.

    2002-01-01

    In this study we tested 4-, 9-, 12-, and 18-month-old C57BL/6 mice in the 250-msec delay eyeblink classical conditioning procedure to study age-related changes in a form of associative learning. The short life expectancy of mice, complete knowledge about the mouse genome, and the availability of transgenic and knock-out mouse models of age-related impairments make the mouse an excellent species for expanding knowledge on the neurobiologically and behaviorally well-characterized eyeblink classical conditioning paradigm. Based on previous research with delay eyeblink conditioning in rabbits and humans, we predicted that mice would be impaired on this cerebellar-dependent associative learning task in middle-age, at ∼9 months. To fully examine age differences in behavior in mice, we used a battery of additional behavioral measures with which to compare young and older mice. These behaviors included the acoustic startle response, prepulse inhibition, rotorod, and the Morris water maze. Mice began to show impairment in cerebellar-dependent tasks such as rotorod and eyeblink conditioning at 9 to 12 months of age. Performance in hippocampally dependent tasks was not impaired in any group, including 18-month-old mice. These results in mice support results in other species, indicating that cerebellar-dependent tasks show age-related deficits earlier in adulthood than do hippocampally dependent tasks. PMID:12359840

  8. Effects of Paradigm and Inter-Stimulus Interval on Age Differences in Eyeblink Classical Conditioning in Rabbits

    ERIC Educational Resources Information Center

    Woodruff-Pak, Diana S.; Seta, Susan E.; Roker, LaToya A.; Lehr, Melissa A.

    2007-01-01

    The aim of this study was to examine parameters affecting age differences in eyeblink classical conditioning in a large sample of young and middle-aged rabbits. A total of 122 rabbits of mean ages of 4 or 26 mo were tested at inter-stimulus intervals (ISIs) of 600 or 750 msec in the delay or trace paradigms. Paradigm affected both age groups…

  9. Choline supplementation mitigates trace, but not delay, eyeblink conditioning deficits in rats exposed to alcohol during development.

    PubMed

    Thomas, Jennifer D; Tran, Tuan D

    2012-03-01

    Children exposed to alcohol prenatally suffer from a range of physical, neuropathological, and behavioral alterations, referred to as fetal alcohol spectrum disorders (FASD). Both the cerebellum and hippocampus are affected by alcohol exposure during development, which may contribute to behavioral and cognitive deficits observed in children with FASD. Despite the known neuropathology associated with prenatal alcohol exposure, many pregnant women continue to drink (heavy drinkers, in particular), creating a need to identify effective treatments for their children who are adversely affected by alcohol. We previously reported that choline supplementation can mitigate alcohol's effects on cognitive development, specifically on tasks which depend on the functional integrity of the hippocampus. The present study examined whether choline supplementation could differentially mitigate alcohol's effects on trace eyeblink classical conditioning (ECC, a hippocampal-dependent task) and delay ECC (a cerebellar-dependent task). Long-Evans rats were exposed to 5.25 g/kg/day alcohol via gastric intubation from postnatal days (PD) 4-9, a period of brain development equivalent to late gestation in humans. A sham-intubated control group was included. From PD 10-30, subjects received subcutaneous injections of 100 mg/kg choline chloride or vehicle. Beginning on PD 32-34, subjects were trained on either delay or trace eyeblink conditioning. Performance of subjects exposed to alcohol was significantly impaired on both tasks, as indicated by significant reductions in percentage and amplitude of conditioned eyeblink responses, an effect that was attenuated by choline supplementation on the trace, but not delay conditioning task. Indeed, alcohol-exposed subjects treated with choline performed at control levels on the trace eyeblink conditioning task. There were no significant main or interactive effects of sex. These data indicate that choline supplementation can significantly reduce the

  10. Project DyAdd: classical eyeblink conditioning in adults with dyslexia and ADHD.

    PubMed

    Laasonen, Marja; Kauppinen, Jenni; Leppämäki, Sami; Tani, Pekka; Harno, Hanna; Hokkanen, Laura; Wikgren, Jan

    2012-11-01

    In this study of the project DyAdd (Adult Dyslexia and Attention Deficit Disorder in Finland), classical eyeblink conditioning (EBC) was investigated in both delay and trace paradigms in adults (18-55 years) with dyslexia (n = 37), attention deficit-hyperactivity disorder (ADHD; n = 21), their comorbid combination (n = 8), and healthy controls (n = 35). In addition, the profiles of three participants with a rare autosomal dominant cerebellar disease were assessed (episodic ataxia type 2, EA-2). We found that participants with dyslexia were overall slower learners than controls in eyeblink conditioning. Further, they were the only group that had a reduced number of CRs in mediotemporal-dependent trace paradigm compared to the more cerebellum-dependent delay paradigm. Second, ADHD was found to be related to larger CR amplitude. Third, those with a comorbid condition learned faster and manifested CRs that were not well timed. Fourth, the cerebellar patients showed nearly no conditioning at all. Correlations between EBC and various neuropsychological domains (phonological processing, reading, spelling, arithmetic, executive functions, attention, and fine motor control) over all participants resulted in significant relations only for the delay paradigm: Increased amount of reading errors related with later peak latency and increased amount of self-corrections in fine motor control related with larger response magnitude. Within those who conditioned, relations emerged only for the trace paradigm: better spelling was related to larger response magnitude. These results do not lend support to the cerebellar hypothesis of dyslexia. On the contrary, dyslexia in its pure form seems to be related to a relative dysfunction of a larger hippocampal-cerebellar network. Further, larger responses in the ADHD group are suggested to result from their lowered responding threshold.

  11. Lack of renewal effect in extinction of naturally acquired conditioned eyeblink responses, but possible dependency on physical context.

    PubMed

    Claassen, J; Mazilescu, L; Thieme, A; Bracha, V; Timmann, D

    2016-01-01

    Context dependency of extinction is well known and has extensively been studied in fear conditioning, but has rarely been assessed in eyeblink conditioning. One way to demonstrate context dependency of extinction is the renewal effect. ABA paradigms are most commonly used to show the renewal effect of extinguished learned fear: if acquisition takes place in context A, and extinction takes place in context B (extinction phase), learned responses will recover in subsequent extinction trials presented in context A (renewal phase). The renewal effect of the visual threat eyeblink response (VTER), a conditioned eyeblink response, which is naturally acquired in early infancy, was examined in a total of 48 young and healthy participants with two experiments using an ABA paradigm. Twenty paired trials were performed in context A (baseline trials), followed by 50 extinction trials in context B (extinction phase) and 50 extinction trials in context A (renewal phase). In 24 participants, contexts A and B were two different rooms, and in the other 24 participants, two different background colors (orange and blue) and noises were used. To rule out spontaneous recovery, an AAA design was used for comparison. There were significant effects of extinction in both experiments. No significant renewal effects were observed. In experiment 2, however, extinction was significantly less using orange background during extinction compared to the blue background. The present findings suggest that extinction of conditioned eyeblinks depends on the physical context. Findings add to the animal literature that context can play a role in the acquisition of classically conditioned eyeblink responses. Future studies, however, need to be performed to confirm the present findings. Lack of renewal effect may be explained by the highly overlearned character of the VTER.

  12. Examining the effects of former cannabis use on cerebellum-dependent eyeblink conditioning in humans

    PubMed Central

    Steinmetz, Adam B.; Edwards, Chad R.; Vollmer, Jennifer M.; Erickson, Molly A.; O’Donnell, Brian F.; Hetrick, William P.

    2012-01-01

    Rationale Previous work in humans has shown that chronic cannabis users exhibit disruptions in classical eyeblink conditioning (EBC), a form of associative learning that is known to be dependent on the cerebellum. Based upon previous work in animals, it was hypothesized that these learning deficits were related to cannabinoid receptor (CB1R) downregulation. However, it remains unclear whether there is a recovery of cerebellum-dependent learning after the cessation of cannabis use. Methods Therefore, former cannabis users (n=10), current cannabis users (n=10), and cannabis-naïve controls (n=10), all free of DSM-IV Axis-I or -II disorders, were evaluated. A standard delay EBC procedure was utilized in which paired presentations of a conditioned stimulus (CS; e.g., tone) and a co-terminating unconditioned stimulus (US; e.g., ocular air-puff) were administered, thus eliciting a conditioned eyeblink response (CR). The primary dependent measures were percentage of CRs and CR latency across conditioning blocks. Results Similar to prior studies, current cannabis users exhibited marked impairments in both the acquisition and timing of CRs compared to controls. Although former cannabis users showed intact CR acquisition compared to controls, they exhibited significantly impaired (shorter) CR latencies. In both cannabis groups, UR amplitude did not differ from controls, indicating normal US processing. Conclusions These data suggest that a recovery of function has occurred for the learning of the CS–US association, while the accurate timing of the CR shows lasting impairments. Taken together, these results suggest that heavy cannabis use can disrupt timing-related synaptic plasticity within the cerebellum, even after the cessation of cannabis use. PMID:22134474

  13. Extinction, reacquisition, and rapid forgetting of eyeblink conditioning in developing rats

    PubMed Central

    Freeman, John H.

    2014-01-01

    Eyeblink conditioning is a well-established model for studying the developmental neurobiology of associative learning and memory. However, age differences in extinction and subsequent reacquisition have yet to be studied using this model. The present study examined extinction and reacquisition of eyeblink conditioning in developing rats. In Experiment 1, post-natal day (P) 17 and 24 rats were trained to a criterion of 80% conditioned responses (CRs) using stimulation of the middle cerebellar peduncle (MCP) as a conditioned stimulus (CS). Stimulation CS-alone extinction training commenced 24 h later, followed by reacquisition training after the fourth extinction session. Contrary to expected results, rats trained starting on P17 showed significantly fewer CRs to stimulation CS-alone presentations relative to P24s, including fewer CRs as early as the first block of extinction session 1. Furthermore, the P17 group was slower to reacquire following extinction. Experiment 2 was run to determine the extent to which the low CR percentage observed in P17s early in extinction reflected rapid forgetting versus rapid extinction. Twenty-four hours after reaching criterion, subjects were trained in a session split into 50 stimulation CS-unconditioned stimulus paired trials followed immediately by 50 stimulation CS-alone trials. With this “immediate” extinction protocol, CR percentages during the first block of stimulation CS-alone presentations were equivalent to terminal acquisition levels at both ages but extinction was more rapid in the P17 group. These findings indicate that forgetting is observed in P17 relative to P24 rats 24 h following acquisition. The forgetting in P17 rats has important implications for the neurobiological mechanisms of memory in the developing cerebellum. PMID:25403458

  14. Cerebellar tDCS Effects on Conditioned Eyeblinks using Different Electrode Placements and Stimulation Protocols

    PubMed Central

    Beyer, Linda; Batsikadze, Giorgi; Timmann, Dagmar; Gerwig, Marcus

    2017-01-01

    There is good evidence that the human cerebellum is involved in the acquisition and timing of classically conditioned eyeblink responses (CRs). Animal studies suggest that the cerebellum is also important in CR extinction and savings. Cerebellar transcranial direct current stimulation (tDCS) was reported to modulate CR acquisition and timing in a polarity dependent manner. To extent previous findings three experiments were conducted using standard delay eyeblink conditioning. In a between-group design, effects of tDCS were assessed with stimulation over the right cerebellar hemisphere ipsilaterally to the unconditioned stimulus (US). An extracephalic reference electrode was used in Experiment 1 and a cephalic reference in Experiment 2. In both parts the influence on unconditioned eyeblink responses (UR) was investigated by starting stimulation in the second half of the pseudoconditioning phase lasting throughout the first half of paired trials. In a third experiment, effects of cerebellar tDCS during 40 extinction trials were assessed on extinction and reacquisition on the next day. In each experiment, 30 subjects received anodal, cathodal or sham stimulation in a double-blinded fashion. Using the extracephalic reference electrode, no significant effects on CR incidences comparing stimulation groups were observed. Using the cephalic reference anodal as well as cathodal cerebellar tDCS increased CR acquisition compared to sham only on a trend level. Analysis of timing parameters did not reveal significant effects on CR onset and peaktime latencies nor on UR timing. In the third experiment, cerebellar tDCS during extinction trials had no significant effect on extinction and savings on the next day. The present study did not reveal clear polarity dependent effects of cerebellar tDCS on CR acquisition and timing as previously described. Weaker effects may be explained by start of tDCS before the learning phase i.e., offline, individual thresholds and current flow based

  15. Cerebellar tDCS Effects on Conditioned Eyeblinks using Different Electrode Placements and Stimulation Protocols.

    PubMed

    Beyer, Linda; Batsikadze, Giorgi; Timmann, Dagmar; Gerwig, Marcus

    2017-01-01

    There is good evidence that the human cerebellum is involved in the acquisition and timing of classically conditioned eyeblink responses (CRs). Animal studies suggest that the cerebellum is also important in CR extinction and savings. Cerebellar transcranial direct current stimulation (tDCS) was reported to modulate CR acquisition and timing in a polarity dependent manner. To extent previous findings three experiments were conducted using standard delay eyeblink conditioning. In a between-group design, effects of tDCS were assessed with stimulation over the right cerebellar hemisphere ipsilaterally to the unconditioned stimulus (US). An extracephalic reference electrode was used in Experiment 1 and a cephalic reference in Experiment 2. In both parts the influence on unconditioned eyeblink responses (UR) was investigated by starting stimulation in the second half of the pseudoconditioning phase lasting throughout the first half of paired trials. In a third experiment, effects of cerebellar tDCS during 40 extinction trials were assessed on extinction and reacquisition on the next day. In each experiment, 30 subjects received anodal, cathodal or sham stimulation in a double-blinded fashion. Using the extracephalic reference electrode, no significant effects on CR incidences comparing stimulation groups were observed. Using the cephalic reference anodal as well as cathodal cerebellar tDCS increased CR acquisition compared to sham only on a trend level. Analysis of timing parameters did not reveal significant effects on CR onset and peaktime latencies nor on UR timing. In the third experiment, cerebellar tDCS during extinction trials had no significant effect on extinction and savings on the next day. The present study did not reveal clear polarity dependent effects of cerebellar tDCS on CR acquisition and timing as previously described. Weaker effects may be explained by start of tDCS before the learning phase i.e., offline, individual thresholds and current flow based

  16. Modification of persistent responses in medial prefrontal cortex during learning in trace eyeblink conditioning.

    PubMed

    Siegel, Jennifer J

    2014-11-01

    Persistent spiking in response to a discrete stimulus is considered to reflect the active maintenance of a memory for that stimulus until a behavioral response is made. This response pattern has been reported in learning paradigms that impose a temporal gap between stimulus presentation and behavioral response, including trace eyeblink conditioning. However, it is unknown whether persistent responses are acquired as a function of learning or simply represent an already existing category of response type. This fundamental question was addressed by recording single-unit activity in the medial prefrontal cortex (mPFC) of rabbits during the initial learning phase of trace eyeblink conditioning. Persistent responses to the tone conditioned stimulus were observed in the mPFC during the very first training sessions. Further analysis revealed that most cells with persistent responses showed this pattern during the very first training trial, before animals had experienced paired training. However, persistent cells showed reliable decreases in response magnitude over the first training session, which were not observed on the second day of training or for sessions in which learning criterion was met. This modification of response magnitude was specific to persistent responses and was not observed for cells showing phasic tone-evoked responses. The data suggest that persistent responses to discrete stimuli do not require learning but that the ongoing robustness of such responses over the course of training is modified as a result of experience. Putative mechanisms for this modification are discussed, including changes in cellular or network properties, neuromodulatory tone, and/or the synaptic efficacy of tone-associated inputs. Copyright © 2014 the American Physiological Society.

  17. Hippocampal Non-Theta-Contingent Eyeblink Classical Conditioning: A Model System for Neurobiological Dysfunction

    PubMed Central

    Cicchese, Joseph J.; Berry, Stephen D.

    2016-01-01

    Typical information processing is thought to depend on the integrity of neurobiological oscillations that may underlie coordination and timing of cells and assemblies within and between structures. The 3–7 Hz bandwidth of hippocampal theta rhythm is associated with cognitive processes essential to learning and depends on the integrity of cholinergic, GABAergic, and glutamatergic forebrain systems. Since several significant psychiatric disorders appear to result from dysfunction of medial temporal lobe (MTL) neurochemical systems, preclinical studies on animal models may be an important step in defining and treating such syndromes. Many studies have shown that the amount of hippocampal theta in the rabbit strongly predicts the acquisition rate of classical eyeblink conditioning and that impairment of this system substantially slows the rate of learning and attainment of asymptotic performance. Our lab has developed a brain–computer interface that makes eyeblink training trials contingent upon the explicit presence or absence of hippocampal theta. The behavioral benefit of theta-contingent training has been demonstrated in both delay and trace forms of the paradigm with a two- to fourfold increase in learning speed over non-theta states. The non-theta behavioral impairment is accompanied by disruption of the amplitude and synchrony of hippocampal local field potentials, multiple-unit excitation, and single-unit response patterns dependent on theta state. Our findings indicate a significant electrophysiological and behavioral impact of the pretrial state of the hippocampus that suggests an important role for this MTL system in associative learning and a significant deleterious impact in the absence of theta. Here, we focus on the impairments in the non-theta state, integrate them into current models of psychiatric disorders, and suggest how improvement in our understanding of neurobiological oscillations is critical for theories and treatment of psychiatric

  18. Choline Supplementation Mitigates Trace, but not Delay, Eyeblink Conditioning Deficits in Rats Exposed to Alcohol During Development

    PubMed Central

    Thomas, Jennifer D.; Tran, Tuan D.

    2013-01-01

    Children exposed to alcohol prenatally suffer from a range of physical, neuropathological and behavioral alterations, referred to as Fetal Alcohol Spectrum Disorders (FASD). Both the cerebellum and hippocampus are affected by alcohol exposure during development, which may contribute to behavioral and cognitive deficits observed in children with FASD. Despite the known neuropathology associated with prenatal alcohol exposure, many pregnant women continue to drink (heavy drinkers, in particular), creating a need to identify effective treatments for their children who are adversely affected by alcohol. We previously reported that choline supplementation can mitigate alcohol’s effects on cognitive development, specifically on tasks which depend on the functional integrity of the hippocampus. The present study examined whether choline supplementation could differentially mitigate ethanol’s effects on trace eyeblink classical conditioning (a hippocampal-dependent task) and delay eyeblink classical conditioning (a cerebellar-dependent task). Long-Evans rats were exposed to 5.25 g/kg/day alcohol via gastric intubation from postnatal days (PD) 4-9, a period of brain development equivalent to late gestation in humans. A sham-intubated control group was included. From PD 10-30, subjects received subcutaneous injections of 100 mg/kg choline chloride or vehicle. Beginning on PD 32-34, subjects were trained on either delay or trace eyeblink conditioning. Performance of subjects exposed to alcohol was significantly impaired on both tasks, as indicated by significant reductions in percentage and amplitude of conditioned eyeblink responses, an effect that was attenuated by choline supplementation on the trace, but not delay conditioning task. Indeed, ethanol-exposed subjects treated with choline performed at control levels on the trace eyeblink conditioning task. There were no significant main or interactive effects of sex. These data indicate that choline supplementation can

  19. Impaired delay and trace eyeblink conditioning in school-age children with fetal alcohol syndrome

    PubMed Central

    Jacobson, Sandra W.; Stanton, Mark E.; Dodge, Neil C.; Pienaar, Mariska; Fuller, Douglas S.; Molteno, Christopher D.; Meintjes, Ernesta M.; Hoyme, H. Eugene; Robinson, Luther K.; Khaole, Nathaniel; Jacobson, Joseph L.

    2013-01-01

    Background Classical eyeblink conditioning (EBC) involves contingent temporal pairing of a conditioned stimulus (e.g., tone) with an unconditioned stimulus (e.g., air puff). Impairment of EBC has been demonstrated in studies of alcohol-exposed animals and in children exposed prenatally at heavy levels. Methods Fetal alcohol syndrome (FAS) was diagnosed by expert dysmorphologists in a large sample of Cape Coloured, South African children. Delay EBC was examined in a new sample of 63 children at 11.3 years, and trace conditioning in 32 of the same children at 12.8 years. At each age, two sessions of 50 trials each were administered on the same day; two more sessions the next day, for children not meeting criterion for conditioning. Results 6 of 34 (17.6%) children born to heavy drinkers were diagnosed with FAS, 28 were heavily exposed nonsyndromal (HE), and 29 were non-exposed controls. Only 33.3% with FAS and 42.9% of HE met criterion for delay conditioning, compared with 79.3% of controls. The more difficult trace conditioning task was also highly sensitive to fetal alcohol exposure. Only 16.7% of the FAS and 21.4% of HE met criterion for trace conditioning, compared with 66.7% of controls. The magnitude of the effect of diagnostic group on trace conditioning was not greater than the effect on short delay conditioning, findings consistent with recent rat studies. Longer latency to onset and peak eyeblink CR in exposed children indicated poor timing and failure to blink in anticipation of the puff. Extended training resulted in some but not all of the children reaching criterion. Conclusions These data showing alcohol-related delay and trace conditioning deficits extend our earlier findings of impaired EBC in 5-year-olds to school-age. Alcohol-related impairment in the cerebellar circuitry required for both forms of conditioning may be sufficient to account for the deficit in both tasks. Extended training was beneficial for some exposed children. EBC provides a well

  20. The Impact of Hippocampal Lesions on Trace Eyeblink Conditioning and Forebrain-Cerebellar Interactions

    PubMed Central

    Weiss, Craig; Disterhoft, John F.

    2015-01-01

    Twenty-five years ago Behavioral Neuroscience published a pivotal paper by Moyer, Deyo and Disterhoft (1990) that described the impaired acquisition of trace eyeblink conditioning in rabbits with complete removal of the hippocampus. As part of the Behavioral Neuroscience celebration commemorating the 30th anniversary of the Journal, we reflect upon the impact of that study on understanding the role of the hippocampus, forebrain, and forebrain-cerebellar interactions that mediate acquisition and retention of trace conditioned responses, and of declarative memory more globally. We discuss the expansion of the conditioning paradigm to species other than the rabbit, the heterogeneity of responses among hippocampal neurons during trace conditioning, the responsivity of hippocampal neurons following consolidation of conditioning, the role of awareness in conditioning, how blink conditioning can be used as a translational tool by assaying potential therapeutics for cognitive enhancement, how trace and delay classical conditioning may be used to investigate neurological disorders including Alzheimer's Disease and schizophrenia, and how the two paradigms may be used to understand the relationship between declarative and nondeclarative memory systems. PMID:26214216

  1. Hippocampal theta-band activity and trace eyeblink conditioning in rabbits.

    PubMed

    Nokia, Miriam S; Penttonen, Markku; Korhonen, Tapani; Wikgren, Jan

    2009-06-01

    The authors examined the relationship between hippocampal theta activity and trace eyeblink conditioning. Hippocampal electrophysiological local field potentials were recorded before, during, and after conditioning or explicitly unpaired training sessions in adult male New Zealand White rabbits. As expected, a high relative power of theta activity (theta ratio) in the hippocampus predicted faster acquisition of the conditioned response during trace conditioning but, contrary to previous results obtained using the delay paradigm, only in the initial stage of learning. The presentation of the conditioned stimulus overall elicited an increase in the hippocampal theta ratio. The theta ratio decreased in the unpaired group as a function of training, remained high throughout conditioning in the fast learners, and rapidly increased in the slow learners initially showing a low theta ratio. Our results indicate a reciprocal connection between the hippocampal oscillatory activity and associative learning. The hippocampal theta ratio seems to reflect changes and differences in the subjects' alertness and responsiveness to external stimuli, which affect the rate of learning and are, in turn, affected by both conditioning and unpaired training.

  2. Cerebellar cortex and cerebellar nuclei are concomitantly activated during eyeblink conditioning: a 7T fMRI study in humans.

    PubMed

    Thürling, Markus; Kahl, Fabian; Maderwald, Stefan; Stefanescu, Roxana M; Schlamann, Marc; Boele, Henk-Jan; De Zeeuw, Chris I; Diedrichsen, Jörn; Ladd, Mark E; Koekkoek, Sebastiaan K E; Timmann, Dagmar

    2015-01-21

    There are controversies whether learning of conditioned eyeblink responses primarily takes place within the cerebellar cortex, the interposed nuclei, or both. It has also been suggested that the cerebellar cortex may be important during early stages of learning, and that there is a shift to the cerebellar nuclei during later stages. As yet, human studies have provided little to resolve this question. In the present study, we established a setup that allows ultra-high-field 7T functional magnetic resonance imaging (fMRI) of the cerebellar cortex and interposed cerebellar nuclei simultaneously during delay eyeblink conditioning in humans. Event-related fMRI signals increased concomitantly in the cerebellar cortex and nuclei during early acquisition of conditioned eyeblink responses in 20 healthy human subjects. ANOVAs with repeated-measures showed significant effects of time across five blocks of 20 conditioning trials in the cortex and nuclei (p < 0.05, permutation corrected). Activations were most pronounced in, but not limited to, lobules VI and interposed nuclei. Increased activations were most prominent at the first time the maximum number of conditioned responses was achieved. Our data are consistent with a simultaneous and synergistic two-site model of learning during acquisition of classically conditioned eyeblinks. Because increased MRI signal reflects synaptic activity, concomitantly increased signals in the cerebellar nuclei and cortex are consistent with findings of learning related potentiation at the mossy fiber to nuclear cell synapse and mossy fiber to granule cell synapse. Activity related to the expression of conditioned responses, however, cannot be excluded.

  3. Hippocampal theta activity is selectively associated with contingency detection but not discrimination in rabbit discrimination-reversal eyeblink conditioning.

    PubMed

    Nokia, Miriam S; Wikgren, Jan

    2010-04-01

    The relative power of the hippocampal theta-band ( approximately 6 Hz) activity (theta ratio) is thought to reflect a distinct neural state and has been shown to affect learning rate in classical eyeblink conditioning in rabbits. We sought to determine if the theta ratio is mostly related to the detection of the contingency between the stimuli used in conditioning or also to the learning of more complex inhibitory associations when a highly demanding delay discrimination-reversal eyeblink conditioning paradigm is used. A high hippocampal theta ratio was not only associated with a fast increase in conditioned responding in general but also correlated with slow emergence of discriminative responding due to sustained responding to the conditioned stimulus not paired with an unconditioned stimulus. The results indicate that the neural state reflected by the hippocampal theta ratio is specifically linked to forming associations between stimuli rather than to the learning of inhibitory associations needed for successful discrimination. This is in line with the view that the hippocampus is responsible for contingency detection in the early phase of learning in eyeblink conditioning.

  4. Metabolic Mapping of Rat Forebrain and Midbrain During Delay and Trace Eyeblink Conditioning

    PubMed Central

    Plakke, Bethany; Freeman, John H.; Poremba, Amy

    2012-01-01

    While the essential neural circuitry for delay eyeblink conditioning has been largely identified, much of the neural circuitry for trace conditioning has yet to be determined. The major difference between delay and trace conditioning is a time gap between the presentation of the conditioned stimulus (CS) and the unconditioned stimulus (US) during trace conditioning. It is this time gap, which accounts for the additional memory component and may require extra neural structures, including hippocampus and prefrontal cortex. A metabolic marker of energy use, radioactively labeled glucose analog, was used to compare differences in glucose analog uptake between delay, trace, and unpaired experimental groups (rats, Long-Evans), to identify possible new areas of involvement within forebrain and midbrain. Here, we identify increased 2-DG uptake for the delay group compared to the unpaired group in various areas including: the medial geniculate nuclei (MGN), the amygdala, cingulate cortex, auditory cortex, medial dorsal thalamus, and frontal cortices. For the trace group, compared to the unpaired group, there was an increase in 2-DG uptake for the medial orbital frontal cortex and the medial MGN. The trace group also exhibited more increases lateralized to the right hemisphere, opposite to the side of US delivery, in various areas including: CA1, subiculum, presubiculum, perirhinal cortex, ventral and dorsal MGN, and the basolateral and central amygdala. While some of these areas have been identified as important for delay or trace conditioning, some new structures have been identified such as the orbital frontal cortex for both delay and trace groups. PMID:19376256

  5. Classical and instrumental conditioning of eyeblink responses in Wistar-Kyoto and Sprague-Dawley rats.

    PubMed

    Ricart, Thomas M; Jiao, Xilu; Pang, Kevin C H; Beck, Kevin D; Servatius, Richard J

    2011-01-01

    Wistar-Kyoto (WKY) rats, an animal model of anxiety vulnerability, acquire lever-press avoidance faster than outbred Sprague-Dawley (SD) rats. Faster avoidance acquisition may reflect an inherent ability to acquire cue-outcome associations, response-outcome associations or both. To evaluate cue-outcome learning, acquisition of classically conditioned eyeblink response was compared in SD and WKY rats using a delay-type paradigm (500-ms conditioned stimulus (CS) coterminating with a 10-ms unconditional stimulus (US)). WKY rats demonstrated enhanced classical conditioning, with both faster acquisition and greater asymptotic performance in delay-type training than SD rats. To evaluate response-outcome learning, separate SD and WKY rats were given control over US delivery through imposition of an omission contingency into delay-type training (emitting a conditioned response (CR) prevented delivery of the US). The schedule of US delivery derived by these rats became the training regimen for a separate group of SD and WKY rats, yoked within strain. In SD rats, no differences in acquisition were detected between those given control over US delivery and those trained with the same partial reinforcement schedule. Acquisition rates of those WKY rats with control exceeded those trained with a yoked-schedule of US presentation. Collectively, WKY rats exhibit enhanced classical conditioning and sensitivity to schedules of reinforcement compared to outbred SD rats. Anxiety vulnerability, in particular inhibited temperament, may be traced to active processes in the prediction and control of aversive events.

  6. Neuroscience and Learning: Lessons from Studying the Involvement of a Region of Cerebellar Cortex in Eyeblink Classical Conditioning

    PubMed Central

    Villarreal, Ronald P; Steinmetz, Joseph E

    2005-01-01

    How the nervous system encodes learning and memory processes has interested researchers for 100 years. Over this span of time, a number of basic neuroscience methods has been developed to explore the relationship between learning and the brain, including brain lesion, stimulation, pharmacology, anatomy, imaging, and recording techniques. In this paper, we summarize how different research approaches can be employed to generate converging data that speak to how structures and systems in the brain are involved in simple associative learning. To accomplish this, we review data regarding the involvement of a particular region of cerebellar cortex (Larsell's lobule HVI) in the widely used paradigm of classical eyeblink conditioning. We also present new data on the role of lobule HVI in eyeblink conditioning generated by combining temporary brain inactivation and single-cell recording methods, an approach that looks promising for further advancing our understanding of relationships between brain and behavior. PMID:16596983

  7. Eyeblink Classical Conditioning and Post-Traumatic Stress Disorder – A Model Systems Approach

    PubMed Central

    Schreurs, Bernard G.; Burhans, Lauren B.

    2015-01-01

    Not everyone exposed to trauma suffers flashbacks, bad dreams, numbing, fear, anxiety, sleeplessness, hyper-vigilance, hyperarousal, or an inability to cope, but those who do may suffer from post-traumatic stress disorder (PTSD). PTSD is a major physical and mental health problem for military personnel and civilians exposed to trauma. There is still debate about the incidence and prevalence of PTSD especially among the military, but for those who are diagnosed, behavioral therapy and drug treatment strategies have proven to be less than effective. A number of these treatment strategies are based on rodent fear conditioning research and are capable of treating only some of the symptoms because the extinction of fear does not deal with the various forms of hyper-vigilance and hyperarousal experienced by people with PTSD. To help address this problem, we have developed a preclinical eyeblink classical conditioning model of PTSD in which conditioning and hyperarousal can both be extinguished. We review this model and discuss findings showing that unpaired stimulus presentations can be effective in reducing levels of conditioning and hyperarousal even when unconditioned stimulus intensity is reduced to the point where it is barely capable of eliciting a response. These procedures have direct implications for the treatment of PTSD and could be implemented in a virtual reality environment. PMID:25904874

  8. Eyeblink classical conditioning and post-traumatic stress disorder - a model systems approach.

    PubMed

    Schreurs, Bernard G; Burhans, Lauren B

    2015-01-01

    Not everyone exposed to trauma suffers flashbacks, bad dreams, numbing, fear, anxiety, sleeplessness, hyper-vigilance, hyperarousal, or an inability to cope, but those who do may suffer from post-traumatic stress disorder (PTSD). PTSD is a major physical and mental health problem for military personnel and civilians exposed to trauma. There is still debate about the incidence and prevalence of PTSD especially among the military, but for those who are diagnosed, behavioral therapy and drug treatment strategies have proven to be less than effective. A number of these treatment strategies are based on rodent fear conditioning research and are capable of treating only some of the symptoms because the extinction of fear does not deal with the various forms of hyper-vigilance and hyperarousal experienced by people with PTSD. To help address this problem, we have developed a preclinical eyeblink classical conditioning model of PTSD in which conditioning and hyperarousal can both be extinguished. We review this model and discuss findings showing that unpaired stimulus presentations can be effective in reducing levels of conditioning and hyperarousal even when unconditioned stimulus intensity is reduced to the point where it is barely capable of eliciting a response. These procedures have direct implications for the treatment of PTSD and could be implemented in a virtual reality environment.

  9. Cannabis Use Disrupts Eyeblink Conditioning: Evidence for Cannabinoid Modulation of Cerebellar-Dependent Learning

    PubMed Central

    Skosnik, Patrick D.; Edwards, Chad R.; O’Donnell, Brian F.; Steffen, Ashley; Steinmetz, Joseph E.; Hetrick, William P.

    2010-01-01

    While the cerebellum contains the highest density of cannabinoid receptor (CB1) in the brain, no studies have assessed the effect of exogenous cannabinoids on cerebellar-dependent learning in humans. The current study therefore examined the effect of chronic cannabis use on classical eyeblink conditioning (EBC), a cerebellar-mediated task which has been shown to be disrupted in CB1 knockout mice. Chronic cannabis users (24 hours abstinence prior to study; positive THC urine drug test) free of DSM-IV Axis I or Axis II disorders, were evaluated. A delay EBC task was utilized, in which a conditioned stimulus (CS; 400 ms tone) co-terminated with a corneal air puff unconditioned stimulus (US; 50 ms), thus eliciting a conditioned blink response (CR). The cannabis group exhibited markedly fewer, and more poorly timed CRs as compared to drug-nal̈ve controls. There were no differences between the groups in either the UR or an EEG measure of selective attention to the CS (N100 auditory ERP), indicating that the disruption observed in the cannabis group was specific to CR acquisition. These results suggest that cannabis use is associated with functional deficits in the cerebellar circuitry underlying EBC, a finding which corroborates recent work in CB1 knockout mice. PMID:17637608

  10. Hippocampal Response Patterns during Discriminative Eyeblink/Jaw Movement Conditioning in the Rabbit

    PubMed Central

    Mauldin, Kristin N.; Griffin, Amy L.; Oliver, Celia G.; Berry, Stephen D.

    2008-01-01

    Rabbits were given concurrent training in eyeblink (EB) and jaw movement (JM) conditioning in which one tone predicted an airpuff and another tone predicted water. After 10 days of discrimination training, the animals were given 10 days of reversal training. In the discrimination phase, acquisition of the two conditioned responses was not significantly different; however JM discrimination errors were much more frequent than EB errors. In the reversal phase, correct performance on EB trials increased gradually, as expected, whereas there was immediate behavioral reversal on JM trials. Differences in size and topography of dorsal CA1 multiple unit responses reflected the ability of the hippocampus to discriminate between stimuli in trained animals, corresponding to the performance of the behavioral discrimination. During jaw movement trials, the rhythmicity of the neural response was further modulated by the type of the prior trial, suggesting the coding of sequential events by the hippocampus. Thus, hippocampal conditioned activity can rapidly change its magnitude and pattern depending on the specific trial type during a concurrent EB/JM discrimination task and its reversal. PMID:18823166

  11. Cannabis use disrupts eyeblink conditioning: evidence for cannabinoid modulation of cerebellar-dependent learning.

    PubMed

    Skosnik, Patrick D; Edwards, Chad R; O'Donnell, Brian F; Steffen, Ashley; Steinmetz, Joseph E; Hetrick, William P

    2008-05-01

    While the cerebellum contains the highest density of cannabinoid receptor (CB1) in the brain, no studies have assessed the effect of exogenous cannabinoids on cerebellar-dependent learning in humans. The current study, therefore, examined the effect of chronic cannabis use on classical eyeblink conditioning (EBC), a cerebellar-mediated task which has been shown to be disrupted in CB1 knockout mice. Chronic cannabis users (24 h abstinence before study; positive THC urine drug test) free of DSM-IV Axis-I or -II disorders, were evaluated. A delay EBC task was utilized, in which a conditioned stimulus (CS; 400 ms tone) co-terminated with a corneal air puff unconditioned stimulus (US; 50 ms), thus eliciting a conditioned blink response (CR). The cannabis group exhibited markedly fewer, and more poorly timed CRs as compared to drug-naive controls. There were no differences between the groups in either the unconditioned response (UR) or an EEG measure of selective attention to the CS (N100 auditory ERP), indicating that the disruption observed in the cannabis group was specific to CR acquisition. These results suggest that cannabis use is associated with functional deficits in the cerebellar circuitry underlying EBC, a finding which corroborates the recent work in CB1 knockout mice.

  12. A Variable Oscillator Underlies the Measurement of Time Intervals in the Rostral Medial Prefrontal Cortex during Classical Eyeblink Conditioning in Rabbits.

    PubMed

    Caro-Martín, C Rocío; Leal-Campanario, Rocío; Sánchez-Campusano, Raudel; Delgado-García, José M; Gruart, Agnès

    2015-11-04

    We were interested in determining whether rostral medial prefrontal cortex (rmPFC) neurons participate in the measurement of conditioned stimulus-unconditioned stimulus (CS-US) time intervals during classical eyeblink conditioning. Rabbits were conditioned with a delay paradigm consisting of a tone as CS. The CS started 50, 250, 500, 1000, or 2000 ms before and coterminated with an air puff (100 ms) directed at the cornea as the US. Eyelid movements were recorded with the magnetic search coil technique and the EMG activity of the orbicularis oculi muscle. Firing activities of rmPFC neurons were recorded across conditioning sessions. Reflex and conditioned eyelid responses presented a dominant oscillatory frequency of ≈12 Hz. The firing rate of each recorded neuron presented a single peak of activity with a frequency dependent on the CS-US interval (i.e., ≈12 Hz for 250 ms, ≈6 Hz for 500 ms, and≈3 Hz for 1000 ms). Interestingly, rmPFC neurons presented their dominant firing peaks at three precise times evenly distributed with respect to CS start and also depending on the duration of the CS-US interval (only for intervals of 250, 500, and 1000 ms). No significant neural responses were recorded at very short (50 ms) or long (2000 ms) CS-US intervals. rmPFC neurons seem not to encode the oscillatory properties characterizing conditioned eyelid responses in rabbits, but are probably involved in the determination of CS-US intervals of an intermediate range (250-1000 ms). We propose that a variable oscillator underlies the generation of working memories in rabbits. The way in which brains generate working memories (those used for the transient processing and storage of newly acquired information) is still an intriguing question. Here, we report that the firing activities of neurons located in the rostromedial prefrontal cortex recorded in alert behaving rabbits are controlled by a dynamic oscillator. This oscillator generated firing frequencies in a variable band

  13. Intra-cerebellar infusion of the protein kinase Mzeta (PKMζ) inhibitor ZIP disrupts eyeblink classical conditioning

    PubMed Central

    Chihabi, Kutibh; Morielli, Anthony D.; Green, John T.

    2016-01-01

    PKM-ζ, a constitutively active N-terminal truncated form of PKC-ζ, has long been implicated in a cellular correlate of learning, long-term potentiation (LTP). Inhibition of PKM-ζ with Zeta-inhibitory peptide (ZIP) has been shown in many brain structures to disrupt maintenance of AMPA receptors, irreversibly disrupting numerous forms of learning and memory that have been maintained for weeks. Delay eyeblink conditioning (EBC) is an established model for the assessment of cerebellar learning; here, we show that PKC-ζ and PKM-ζ are highly expressed in the cerebellar cortex, with highest expression found in Purkinje cell (PC) nuclei. Despite being highly expressed in the cerebellar cortex, no studies have examined how regulation of cerebellar PKM-ζ may affect cerebellar-dependent learning and memory. Given its disruption of learning in other brain structures, we hypothesized that ZIP would also disrupt delay EBC. We have shown that infusion of ZIP into the lobulus simplex of the rat cerebellar cortex can indeed significantly disrupt delay EBC. PMID:26949968

  14. Eyeblink Conditioning and Novel Object Recognition in the Rabbit: Behavioral Paradigms for Assaying Psychiatric Diseases

    PubMed Central

    Weiss, Craig; Disterhoft, John F.

    2015-01-01

    Analysis of data collected from behavioral paradigms has provided important information for understanding the etiology and progression of diseases that involve neural regions mediating abnormal behavior. The trace eyeblink conditioning (EBC) paradigm is particularly suited to examine cerebro-cerebellar interactions since the paradigm requires the cerebellum, forebrain, and awareness of the stimulus contingencies. Impairments in acquiring EBC have been noted in several neuropsychiatric conditions, including schizophrenia, Alzheimer’s disease (AD), progressive supranuclear palsy, and post-traumatic stress disorder. Although several species have been used to examine EBC, the rabbit is unique in its tolerance for restraint, which facilitates imaging, its relatively large skull that facilitates chronic neuronal recordings, a genetic sequence for amyloid that is identical to humans which makes it a valuable model to study AD, and in contrast to rodents, it has a striatum that is differentiated into a caudate and a putamen that facilitates analysis of diseases involving the striatum. This review focuses on EBC during schizophrenia and AD since impairments in cerebro-cerebellar connections have been hypothesized to lead to a cognitive dysmetria. We also relate EBC to conditioned avoidance responses that are more often examined for effects of antipsychotic medications, and we propose that an analysis of novel object recognition (NOR) may add to our understanding of how the underlying neural circuitry has changed during disease states. We propose that the EBC and NOR paradigms will help to determine which therapeutics are effective for treating the cognitive aspects of schizophrenia and AD, and that neuroimaging may reveal biomarkers of the diseases and help to evaluate potential therapeutics. The rabbit, thus, provides an important translational system for studying neural mechanisms mediating maladaptive behaviors that underlie some psychiatric diseases, especially

  15. Enhanced Eyeblink Conditioning in Behaviorally Inhibited Individuals is Disrupted by Proactive Interference Following US Alone Pre-exposures.

    PubMed

    Allen, Michael Todd; Miller, Daniel P

    2016-01-01

    Anxiety vulnerable individuals exhibit enhanced acquisition of conditioned eyeblinks as well as enhanced proactive interference from conditioned stimulus (CS) or unconditioned stimulus (US) alone pre-exposures (Holloway et al., 2012). US alone pre-exposures disrupt subsequent conditioned response (CR) acquisition to CS-US paired trials as compared to context pre-exposure controls. While Holloway et al. (2012) reported enhanced acquisition in high trait anxiety individuals in the context condition, anxiety vulnerability effects were not reported for the US alone pre-exposure group. It appears from the published data that there were no differences between high and low anxiety individuals in the US alone condition. In the work reported here, we sought to extend the findings of enhanced proactive interference with US alone pre-exposures to determine if the enhanced conditioning was disrupted by proactive interference procedures. We also were interested in the spontaneous eyeblinks during the pre-exposure phase of training. We categorized individuals as anxiety vulnerability or non-vulnerable individuals based scores on the Adult Measure of Behavioral Inhibition (AMBI). Sixty-six participants received 60 trials consisting of 30 US alone or context alone pre-exposures followed by 30 CS-US trials. US alone pre-exposures not only disrupted CR acquisition overall, but behaviorally inhibited (BI) individuals exhibited enhanced proactive interference as compared to non-inhibited (NI) individuals. In addition, US alone pre-exposures disrupted the enhanced acquisition observed in BI individuals as compared to NI individuals following context alone pre-exposures. Differences were also found in rates of spontaneous eyeblinks between BI and NI individuals during context pre-exposure. Our findings will be discussed in the light of the neural substrates of eyeblink conditioning as well as possible factors such as hypervigilance in the amygdala and hippocampal systems, and possible

  16. Discriminative delay Pavlovian eyeblink conditioning in veterans with and without posttraumatic stress disorder.

    PubMed

    Ginsberg, J P; Ayers, Edwin; Burriss, Louisa; Powell, D A

    2008-06-01

    Impaired eyeblink (EB) classical conditioning using a delay paradigm has previously been shown in combat veterans, as well as in a group of depressed adults, compared to normal individuals. Significant deficits in immediate memory (IM) in combat PTSD+ veterans, compared to normal controls, have also been previously shown, but these differences became non-significant after controlling for level of self-reported depression. Furthermore, EB conditioning has been shown to be significantly correlated with heart rate variability (HRV) in normal adults. The present study examined how depression (self-reported), IM, and resting HRV are related to discriminative delay classical EB conditioning in veterans with and without PTSD. Three groups of subjects (combat PTSD+, combat PTSD-, and non-combat PTSD-) were assessed for self-report of depression and anxiety, as well as IM and HRV. Subjects received a single session of discriminative EB classical conditioning in which the conditioned stimulus (CS) was a light signal (either red or green) compounded with a tone. On CS+ trials, the light-tone compound stimulus co-terminated with a corneal airpuff (unconditioned stimulus, US), thus producing a delay paradigm. On CS- trials the appropriate light-tone stimulus was presented but not followed by the airpuff US. EB amplitude and frequency were recorded. PTSD+ subjects had greater self-reported depression and anxiety scores than the two control groups, as well as lower scores on a measure of IM. However, the IM difference was not significant after the effects of self-reported depression and anxiety were controlled. EB CR amplitude was significantly greater to CS+ than CS- for all three groups. EB amplitude to both the US (airpuff) and the CS+ declined over trials, but was significantly lower in the combat PTSD+ group compared to the combined PTSD- groups. Subjects who reached an EB CR acquisition criterion had significantly greater scores on IM than those who did not reach criterion

  17. Surface electromyography recording of spontaneous eyeblinks: applications in neuroprosthetics.

    PubMed

    Frigerio, Alice; Brenna, Stefano; Cavallari, Paolo

    2013-02-01

    We are designing an implantable neuroprosthesis for the treatment of unilateral facial paralysis. The envisioned biomimetic device paces artificial blinks in the paretic eyelid when activity in the healthy orbicularis oculi (orbicularis) muscle is detected. The present article focuses on electromyography (EMG)-based eyeblink detection. A pilot clinical study was performed in healthy volunteers who were intended to represent individuals with facial paralysis. Spontaneous eyeblinks were detected by a surface EMG recording. Blink detection accuracy was tested at rest and during voluntary smiling and chewing. Fifteen participants were asked to wear surface recording electrodes on the left side of their face, detecting the orbicularis oculi, the masseter, and the zygomatic muscle EMG activity. Participants were asked to look ahead, voluntarily smile, and chew according to an experimental protocol. Custom software was designed with the purpose of selectively filtering the multichannel EMG recordings and triggering a digital output. The software filter allowed elimination of spurious artificial eyeblinks and thus increased the accuracy of the EMG recording apparatus for the spontaneous blinking. Orbicularis oculi EMG recording worked as a real-time eyeblink-detecting system. Moreover, the multichannel EMG recording coupled to a proper digital signal processing was very effective in specifically detecting the spontaneous blinking during other facial muscle activities. With regard to closed-loop biomimetic devices for the pacing of the eyeblink, the EMG signal represents a valid option for the recording side.

  18. Behaviorally-inhibited temperament is associated with severity of PTSD symptoms and faster eyeblink conditioning in veterans

    PubMed Central

    Myers, Catherine E.; VanMeenen, Kirsten M.; McAuley, J. Devin; Beck, Kevin D.; Pang, Kevin C. H.; Servatius, Richard J.

    2012-01-01

    Prior studies have sometimes demonstrated facilitated acquisition of classically-conditioned responses and/or resistance to extinction in post-traumatic stress disorder (PTSD). However, it is unclear whether these behaviors are acquired as a result of PTSD or exposure to trauma, or reflect pre-existing risk factors that confer vulnerability for PTSD. Here, we examined classical eyeblink conditioning and extinction in veterans self-assessed for current PTSD symptoms, exposure to combat, and the personality trait of behavioral inhibition (BI), a risk factor for PTSD. 128 veterans were recruited (mean age 51.2 years; 13.3% female); 126 completed self-assessment, with 25.4% reporting a history of exposure to combat and 30.9% reporting severe, current PTSD symptoms (PTSS). PTSD symptom severity was correlated with current BI (R2=0.497) and PTSS status could be predicted based on current BI and combat history (80.2% correct classification). A subset of the veterans (n=87) also completed eyeblink conditioning. Among veterans without PTSS, childhood BI was associated with faster acquisition; veterans with PTSS showed delayed extinction, under some conditions. These data demonstrate a relationship between current BI and PTSS, and suggest that the facilitated conditioning sometimes observed in PTSD patients may partially reflect personality traits such as childhood BI that pre-date and contribute to vulnerability for PTSD. PMID:21790343

  19. Awareness is essential for differential delay eyeblink conditioning with soft-tone but not loud-tone conditioned stimuli.

    PubMed

    Huang, He; Wu, Bing; Li, Qiong; Yao, Juan; Li, Xuan; Yang, Yi; Wu, Guang-Yan; Sui, Jian-Feng

    2014-06-01

    The role of awareness in differential delay eyeblink conditioning (DEC) remains controversial. Here, we investigated the involvement of awareness in differential DEC with a soft or a loud tone as the conditioned stimulus (CS). In the experiment, 36 participants were trained in differential DEC with a soft tone (60 dB) or a loud tone (85 dB) as the CS, paired with a corneal air-puff as the unconditioned stimulus (US). After conditioning, awareness of the relationship between the CS and the US was assessed with a 17-item true/false questionnaire. Interestingly, during differential DEC with a soft-tone CS, a higher proportion of differential conditioned responses (CRs) was evident in participants who were aware than those who were unaware. In contrast, when a loud tone was used as the CS, the proportion of differential CRs of the aware participants did not differ significantly from those who were unaware over any of the blocks of 20 trials. In unaware participants, the percentage of differential CRs with a loud-tone CS was significantly higher than that with a soft-tone CS; however in participants classified as aware, the percentage of differential CRs with a loud-tone CS did not differ significantly from that with a soft-tone CS. The present findings suggest that awareness is critical for differential DEC when the delay task is rendered more difficult.

  20. Effects of paradigm and inter-stimulus interval on age differences in eyeblink classical conditioning in rabbits

    PubMed Central

    Woodruff-Pak, Diana S.; Seta, Susan E.; Roker, LaToya A.; Lehr, Melissa A.

    2007-01-01

    The aim of this study was to examine parameters affecting age differences in eyeblink classical conditioning in a large sample of young and middle-aged rabbits. A total of 122 rabbits of mean ages of 4 or 26 mo were tested at inter-stimulus intervals (ISIs) of 600 or 750 msec in the delay or trace paradigms. Paradigm affected both age groups dramatically, with superior performance in the delay paradigm. ISI was salient as middle-aged rabbits were significantly impaired in 750-msec compared with 600-msec delays, and young rabbits were significantly less impaired in 600-msec than in 750-msec trace. Young rabbits performed equally well at both delay ISIs, and consequently, there were significant age differences in 750-msec but not in 600-msec delays. Middle-aged rabbits performed poorly at both 600- and 750-msec trace, resulting in significant age differences in 600-msec but not in 750-msec trace. Timing of the conditioned response has been associated with cerebellar cortical function. Normal aging of the cerebellar cortex likely contributed to the magnitude of the effect of ISI in delay conditioning in middle-aged rabbits. Results demonstrate that the magnitude of age differences in eyeblink conditioning can be enlarged or eliminated by ISI and paradigm. PMID:17522017

  1. NMDA Receptor-Dependent Processes in the Medial Prefrontal Cortex Are Important for Acquisition and the Early Stage of Consolidation during Trace, but Not Delay Eyeblink Conditioning

    ERIC Educational Resources Information Center

    Takehara-Nishiuchi, Kaori; Kawahara, Shigenori; Kirino, Yutaka

    2005-01-01

    Permanent lesions in the medial prefrontal cortex (mPFC) affect acquisition of conditioned responses (CRs) during trace eyeblink conditioning and retention of remotely acquired CRs. To clarify further roles of the mPFC in this type of learning, we investigated the participation of the mPFC in mnemonic processes both during and after daily…

  2. Acute Stress Facilitates Trace Eyeblink Conditioning in C57BL/6 Male Mice and Increases the Excitability of Their CA1 Pyramidal Neurons

    ERIC Educational Resources Information Center

    Weiss, Craig; Sametsky, Evgeny; Sasse, Astrid; Spiess, Joachim; Disterhoft, John F.

    2005-01-01

    The effects of stress (restraint plus tail shock) on hippocampus-dependent trace eyeblink conditioning and hippocampal excitability were examined in C57BL/6 male mice. The results indicate that the stressor significantly increased the concentration of circulating corticosterone, the amount and rate of learning relative to nonstressed conditioned…

  3. Acute Stress Facilitates Trace Eyeblink Conditioning in C57BL/6 Male Mice and Increases the Excitability of Their CA1 Pyramidal Neurons

    ERIC Educational Resources Information Center

    Weiss, Craig; Sametsky, Evgeny; Sasse, Astrid; Spiess, Joachim; Disterhoft, John F.

    2005-01-01

    The effects of stress (restraint plus tail shock) on hippocampus-dependent trace eyeblink conditioning and hippocampal excitability were examined in C57BL/6 male mice. The results indicate that the stressor significantly increased the concentration of circulating corticosterone, the amount and rate of learning relative to nonstressed conditioned…

  4. I Think, Therefore Eyeblink

    PubMed Central

    Weidemann, Gabrielle; Satkunarajah, Michelle; Lovibond, Peter F.

    2016-01-01

    Can conditioning occur without conscious awareness of the contingency between the stimuli? We trained participants on two separate reaction time tasks that ensured attention to the experimental stimuli. The tasks were then interleaved to create a differential Pavlovian contingency between visual stimuli from one task and an airpuff stimulus from the other. Many participants were unaware of the contingency and failed to show differential eyeblink conditioning, despite attending to a salient stimulus that was contingently and contiguously related to the airpuff stimulus over many trials. Manipulation of awareness by verbal instruction dramatically increased awareness and differential eyeblink responding. These findings cast doubt on dual-system theories, which propose an automatic associative system independent of cognition, and provide strong evidence that cognitive processes associated with awareness play a causal role in learning. PMID:26905277

  5. Cooling of the cerebellar interpositus nucleus abolishes somatosensory cortical learning-related activity in eyeblink conditioned rabbits.

    PubMed

    Wikgren, Jan; Lavond, David G; Ruusuvirta, Timo; Korhonen, Tapani

    2006-06-03

    Nictitating membrane movement and multiple-unit activity in the somatosensory cortex were recorded from rabbits during paired (N=6) and unpaired (N=5) presentations of a tone conditioned stimulus (CS) and an airpuff unconditioned stimulus (US). A behavioural conditioned response (CR) to the CS and an accompanying neural response in the somatosensory cortex developed only in the paired group. Inactivation of the cerebellar interpositus nucleus abolished both the acquired CR and the accompanying neural response. However, the CS facilitated both behavioural and neural responses to the US during the inactivation. Thus, the absence of the CR could not be accounted for by the general inability of the CS to alter the behaviour constituting the CR or the activity of the somatosensory cortex. These findings suggest that the efferent copy of the signal related to the eyeblink CR is projected from the cerebellum to the cerebral cortical areas of the US modality.

  6. Eyeblink Classical Conditioning and Interpositus Nucleus Activity Are Disrupted in Adult Rats Exposed to Ethanol as Neonates

    PubMed Central

    Green, John T.; Johnson, Timothy B.; Goodlett, Charles R.; Steinmetz, Joseph E.

    2002-01-01

    Neonatal exposure to ethanol in rats, during the period of brain development comparable to that of the human third trimester, produces significant, dose-dependent cell loss in the cerebellum and deficits in coordinated motor performance. These rats are also impaired in eyeblink conditioning as weanlings and as adults. The current study examined single-unit neural activity in the interpositus nucleus of the cerebellum in adults following neonatal binge ethanol exposure. Group Ethanol received alcohol doses of 5.25 g/kg/day on postnatal days 4–9. Group Sham Intubated underwent acute intragastric intubation on postnatal days 4–9 but did not receive any infusions. Group Unintubated Control (from separate litters) did not receive any intubations. When rats were 3–7 mo old, pairs of extracellular microelectrodes were implanted in the region of the interpositus nucleus. Beginning 1 wk later, the rats were given either 100 paired or 190 unpaired trials per day for 10 d followed by 4 d of 100 conditioned stimulus (CS)-alone trials per day. As in our previous study, conditioned response acquisition in Group Ethanol rats was impaired. In addition, by session 5 of paired acquisition, Group Sham Intubated and Group Unintubated Control showed significant increases in interpositus nucleus activity, relative to baseline, in the CS–unconditioned stimulus interval. In contrast, Group Ethanol failed to show significant changes in interpositus nucleus activity until later in training. These results indicate that the disruption in eyeblink conditioning after early exposure to ethanol is reflected in alterations in interpositus nucleus activity. PMID:12359839

  7. Harnessing the power of theta: natural manipulations of cognitive performance during hippocampal theta-contingent eyeblink conditioning

    PubMed Central

    Hoffmann, Loren C.; Cicchese, Joseph J.; Berry, Stephen D.

    2015-01-01

    Neurobiological oscillations are regarded as essential to normal information processing, including coordination and timing of cells and assemblies within structures as well as in long feedback loops of distributed neural systems. The hippocampal theta rhythm is a 3–12 Hz oscillatory potential observed during cognitive processes ranging from spatial navigation to associative learning. The lower range, 3–7 Hz, can occur during immobility and depends upon the integrity of cholinergic forebrain systems. Several studies have shown that the amount of pre-training theta in the rabbit strongly predicts the acquisition rate of classical eyeblink conditioning and that impairment of this system substantially slows the rate of learning. Our lab has used a brain-computer interface (BCI) that delivers eyeblink conditioning trials contingent upon the explicit presence or absence of hippocampal theta. A behavioral benefit of theta-contingent training has been demonstrated in both delay and trace forms of the paradigm with a two- to four-fold increase in learning speed. This behavioral effect is accompanied by enhanced amplitude and synchrony of hippocampal local field potential (LFP)s, multi-unit excitation, and single-unit response patterns that depend on theta state. Additionally, training in the presence of hippocampal theta has led to increases in the salience of tone-induced unit firing patterns in the medial prefrontal cortex, followed by persistent multi-unit activity during the trace interval. In cerebellum, rhythmicity and precise synchrony of stimulus time-locked LFPs with those of hippocampus occur preferentially under the theta condition. Here we review these findings, integrate them into current models of hippocampal-dependent learning and suggest how improvement in our understanding of neurobiological oscillations is critical for theories of medial temporal lobe processes underlying intact and pathological learning. PMID:25918501

  8. Model-Driven Analysis of Eyeblink Classical Conditioning Reveals the Underlying Structure of Cerebellar Plasticity and Neuronal Activity.

    PubMed

    Antonietti, Alberto; Casellato, Claudia; D'Angelo, Egidio; Pedrocchi, Alessandra

    2016-09-01

    The cerebellum plays a critical role in sensorimotor control. However, how the specific circuits and plastic mechanisms of the cerebellum are engaged in closed-loop processing is still unclear. We developed an artificial sensorimotor control system embedding a detailed spiking cerebellar microcircuit with three bidirectional plasticity sites. This proved able to reproduce a cerebellar-driven associative paradigm, the eyeblink classical conditioning (EBCC), in which a precise time relationship between an unconditioned stimulus (US) and a conditioned stimulus (CS) is established. We challenged the spiking model to fit an experimental data set from human subjects. Two subsequent sessions of EBCC acquisition and extinction were recorded and transcranial magnetic stimulation (TMS) was applied on the cerebellum to alter circuit function and plasticity. Evolutionary algorithms were used to find the near-optimal model parameters to reproduce the behaviors of subjects in the different sessions of the protocol. The main finding is that the optimized cerebellar model was able to learn to anticipate (predict) conditioned responses with accurate timing and success rate, demonstrating fast acquisition, memory stabilization, rapid extinction, and faster reacquisition as in EBCC in humans. The firing of Purkinje cells (PCs) and deep cerebellar nuclei (DCN) changed during learning under the control of synaptic plasticity, which evolved at different rates, with a faster acquisition in the cerebellar cortex than in DCN synapses. Eventually, a reduced PC activity released DCN discharge just after the CS, precisely anticipating the US and causing the eyeblink. Moreover, a specific alteration in cortical plasticity explained the EBCC changes induced by cerebellar TMS in humans. In this paper, for the first time, it is shown how closed-loop simulations, using detailed cerebellar microcircuit models, can be successfully used to fit real experimental data sets. Thus, the changes of the

  9. Autism and Classical Eyeblink Conditioning: Performance Changes of the Conditioned Response Related to Autism Spectrum Disorder Diagnosis

    PubMed Central

    Welsh, John P.; Oristaglio, Jeffrey T.

    2016-01-01

    Changes in the timing performance of conditioned responses (CRs) acquired during trace and delay eyeblink conditioning (EBC) are presented for diagnostic subgroups of children having autism spectrum disorder (ASD) aged 6–15 years. Children diagnosed with autistic disorder (AD) were analyzed separately from children diagnosed with either Asperger’s syndrome or Pervasive developmental disorder (Asp/PDD) not otherwise specified and compared to an age- and IQ-matched group of children who were typically developing (TD). Within-subject and between-groups contrasts in CR performance on sequential exposure to trace and delay EBC were analyzed to determine whether any differences would expose underlying functional heterogeneities of the cerebral and cerebellar systems, in ASD subgroups. The EBC parameters measured were percentage CRs, CR onset latency, and CR peak latency. Neither AD nor Asp/PDD groups were impaired in CR acquisition during trace or delay EBC. Both AD and Asp/PDD altered CR timing, but not always in the same way. Although the AD group showed normal CR timing during trace EBC, the Asp/PDD group showed a significant 27 and 28 ms increase in CR onset and peak latency, respectively, during trace EBC. In contrast, the direction of the timing change was opposite during delay EBC, during which the Asp/PDD group showed a significant 29 ms decrease in CR onset latency and the AD group showed a larger 77 ms decrease in CR onset latency. Only the AD group showed a decrease in CR peak latency during delay EBC, demonstrating another difference between AD and Asp/PDD. The difference in CR onset latency during delay EBC for both AD and Asp/PDD was due to an abnormal prevalence of early onset CRs that were intermixed with CRs having normal timing, as observed both in CR onset histograms and mean CR waveforms. In conclusion, significant heterogeneity in EBC performance was apparent between diagnostic groups, and this may indicate that EBC performance can report

  10. Deep cerebellar nuclei play an important role in two-tone discrimination on delay eyeblink conditioning in C57BL/6 mice.

    PubMed

    Sakamoto, Toshiro; Endo, Shogo

    2013-01-01

    Previous studies have shown that deep cerebellar nuclei (DCN)-lesioned mice develop conditioned responses (CR) on delay eyeblink conditioning when a salient tone conditioned stimulus (CS) is used, which suggests that the cerebellum potentially plays a role in more complicated cognitive functions. In the present study, we examined the role of DCN in tone frequency discrimination in the delay eyeblink-conditioning paradigm. In the first experiment, DCN-lesioned and sham-operated mice were subjected to standard simple eyeblink conditioning under low-frequency tone CS (LCS: 1 kHz, 80 dB) or high-frequency tone CS (HCS: 10 kHz, 70 dB) conditions. DCN-lesioned mice developed CR in both CS conditions as well as sham-operated mice. In the second experiment, DCN-lesioned and sham-operated mice were subjected to two-tone discrimination tasks, with LCS+ (or HCS+) paired with unconditioned stimulus (US), and HCS- (or LCS-) without US. CR% in sham-operated mice increased in LCS+ (or HCS+) trials, regardless of tone frequency of CS, but not in HCS- (or LCS-) trials. The results indicate that sham-operated mice can discriminate between LCS+ and HCS- (or HCS+ and LCS-). In contrast, DCN-lesioned mice showed high CR% in not only LCS+ (or HCS+) trials but also HCS- (or LCS-) trials. The results indicate that DCN lesions impair the discrimination between tone frequency in eyeblink conditioning. Our results suggest that the cerebellum plays a pivotal role in the discrimination of tone frequency.

  11. Deep Cerebellar Nuclei Play an Important Role in Two-Tone Discrimination on Delay Eyeblink Conditioning in C57BL/6 Mice

    PubMed Central

    Sakamoto, Toshiro; Endo, Shogo

    2013-01-01

    Previous studies have shown that deep cerebellar nuclei (DCN)-lesioned mice develop conditioned responses (CR) on delay eyeblink conditioning when a salient tone conditioned stimulus (CS) is used, which suggests that the cerebellum potentially plays a role in more complicated cognitive functions. In the present study, we examined the role of DCN in tone frequency discrimination in the delay eyeblink-conditioning paradigm. In the first experiment, DCN-lesioned and sham-operated mice were subjected to standard simple eyeblink conditioning under low-frequency tone CS (LCS: 1 kHz, 80 dB) or high-frequency tone CS (HCS: 10 kHz, 70 dB) conditions. DCN-lesioned mice developed CR in both CS conditions as well as sham-operated mice. In the second experiment, DCN-lesioned and sham-operated mice were subjected to two-tone discrimination tasks, with LCS+ (or HCS+) paired with unconditioned stimulus (US), and HCS− (or LCS−) without US. CR% in sham-operated mice increased in LCS+ (or HCS+) trials, regardless of tone frequency of CS, but not in HCS− (or LCS−) trials. The results indicate that sham-operated mice can discriminate between LCS+ and HCS− (or HCS+ and LCS−). In contrast, DCN-lesioned mice showed high CR% in not only LCS+ (or HCS+) trials but also HCS− (or LCS−) trials. The results indicate that DCN lesions impair the discrimination between tone frequency in eyeblink conditioning. Our results suggest that the cerebellum plays a pivotal role in the discrimination of tone frequency. PMID:23555821

  12. Teager–Kaiser energy operator signal conditioning improves EMG onset detection

    PubMed Central

    Rider, Patrick; Steinweg, Ken; DeVita, Paul; Hortobágyi, Tibor

    2010-01-01

    Accurate identification of the onset of muscle activity is an important element in the biomechanical analysis of human movement. The purpose of this study was to determine if inclusion of the Teager–Kaiser energy operator (TKEO) in signal conditioning would increase the accuracy of popular electromyography (EMG) onset detection methods. Three methods, visual determination, threshold-based method, and approximated generalized likelihood ratio were used to estimate the onset of EMG burst with and without TKEO conditioning. Reference signals, with known onset times, were constructed from EMG signals collected during isometric contraction of the vastus lateralis (n = 17). Additionally, vastus lateralis EMG signals (n = 255) recorded during gait were used to evaluate a clinical application of the TKEO conditioning. Inclusion of TKEO in signal conditioning significantly reduced mean detection error of all three methods compared with signal conditioning without TKEO, using artificially generated reference data (13 vs. 98 ms, p < 0.001) and also compared with experimental data collected during gait (55 vs. 124 ms, p < 0.001). In conclusion, addition of TKEO as a step in conditioning surface EMG signals increases the detection accuracy of EMG burst boundaries. PMID:20526612

  13. Eyeblink classical conditioning and BOLD fMRI of anesthesia-induced changes in the developing brain.

    PubMed

    Aksenov, Daniil P; Miller, Michael J; Li, Limin; Wyrwicz, Alice M

    2016-12-01

    Millions of children undergo general anesthesia each year in the USA alone, and a growing body of literature from animals and humans suggests that exposure to anesthesia at an early age can impact neuronal development, leading to learning and memory impairments later in childhood. Although a number of studies have reported behavioral and structural effects of anesthesia exposure during infancy, the functional manifestation of these changes has not been previous examined. In this study we used BOLD fMRI to measure the functional response to stimulation in the whisker barrel cortex of awake rabbits before and after learning a trace eyeblink classical conditioning paradigm. The functional changes, in terms of activated volume and time course, in rabbits exposed to isoflurane anesthesia during infancy was compared to unanesthetized controls when both groups reached young adulthood. Our findings show that whereas both groups exhibited decreased BOLD response duration after learning, the anesthesia-exposed group also showed a decrease in BOLD response volume in the whisker barrel cortex, particularly in the deeper infragranular layer. These results suggest that anesthesia exposure during infancy may affect the intracortical processes that mediate learning-related plasticity.

  14. Reevaluation of the role of parallel fiber synapses in delay eyeblink conditioning in mice using Cbln1 as a tool.

    PubMed

    Emi, Kyoichi; Kakegawa, Wataru; Miura, Eriko; Ito-Ishida, Aya; Kohda, Kazuhisa; Yuzaki, Michisuke

    2013-01-01

    The delay eyeblink conditioning (EBC) is a cerebellum-dependent type of associative motor learning. However, the exact roles played by the various cerebellar synapses, as well as the underlying molecular mechanisms, remain to be determined. It is also unclear whether long-term potentiation (LTP) or long-term depression (LTD) at parallel fiber (PF)-Purkinje cell (PC) synapses is involved in EBC. In this study, to clarify the role of PF synapses in the delay EBC, we used mice in which a gene encoding Cbln1 was disrupted (cbln1(-/-) mice), which display severe reduction of PF-PC synapses. We showed that delay EBC was impaired in cbln1(-/-) mice. Although PF-LTD was impaired, PF-LTP was normally induced in cbln1(-/-) mice. A single recombinant Cbln1 injection to the cerebellar cortex in vivo completely, though transiently, restored the morphology and function of PF-PC synapses and delay EBC in cbln1(-/-) mice. Interestingly, the cbln1(-/-) mice retained the memory for at least 30 days, after the Cbln1 injection's effect on PF synapses had abated. Furthermore, delay EBC memory could be extinguished even after the Cbln1 injection's effect were lost. These results indicate that intact PF-PC synapses and PF-LTD, not PF-LTP, are necessary to acquire delay EBC in mice. In contrast, extracerebellar structures or remaining PF-PC synapses in cbln1(-/-) mice may be sufficient for the expression, maintenance, and extinction of its memory trace.

  15. Trace Eyeblink Conditioning in Mice Is Dependent upon the Dorsal Medial Prefrontal Cortex, Cerebellum, and Amygdala: Behavioral Characterization and Functional Circuitry1,2,3

    PubMed Central

    Taylor, William; Gray, Richard; Kalmbach, Brian; Zemelman, Boris V.; Desai, Niraj S.; Johnston, Daniel; Chitwood, Raymond A.

    2015-01-01

    Abstract Trace eyeblink conditioning is useful for studying the interaction of multiple brain areas in learning and memory. The goal of the current work was to determine whether trace eyeblink conditioning could be established in a mouse model in the absence of elicited startle responses and the brain circuitry that supports this learning. We show here that mice can acquire trace conditioned responses (tCRs) devoid of startle while head-restrained and permitted to freely run on a wheel. Most mice (75%) could learn with a trace interval of 250 ms. Because tCRs were not contaminated with startle-associated components, we were able to document the development and timing of tCRs in mice, as well as their long-term retention (at 7 and 14 d) and flexible expression (extinction and reacquisition). To identify the circuitry involved, we made restricted lesions of the medial prefrontal cortex (mPFC) and found that learning was prevented. Furthermore, inactivation of the cerebellum with muscimol completely abolished tCRs, demonstrating that learned responses were driven by the cerebellum. Finally, inactivation of the mPFC and amygdala in trained animals nearly abolished tCRs. Anatomical data from these critical regions showed that mPFC and amygdala both project to the rostral basilar pons and overlap with eyelid-associated pontocerebellar neurons. The data provide the first report of trace eyeblink conditioning in mice in which tCRs were driven by the cerebellum and required a localized region of mPFC for acquisition. The data further reveal a specific role for the amygdala as providing a conditioned stimulus-associated input to the cerebellum. PMID:26464998

  16. New Insights into the Nature of Cerebellar-Dependent Eyeblink Conditioning Deficits in Schizophrenia: A Hierarchical Linear Modeling Approach.

    PubMed

    Bolbecker, Amanda R; Petersen, Isaac T; Kent, Jerillyn S; Howell, Josselyn M; O'Donnell, Brian F; Hetrick, William P

    2016-01-01

    Evidence of cerebellar dysfunction in schizophrenia has mounted over the past several decades, emerging from neuroimaging, neuropathological, and behavioral studies. Consistent with these findings, cerebellar-dependent delay eyeblink conditioning (dEBC) deficits have been identified in schizophrenia. While repeated-measures analysis of variance is traditionally used to analyze dEBC data, hierarchical linear modeling (HLM) more reliably describes change over time by accounting for the dependence in repeated-measures data. This analysis approach is well suited to dEBC data analysis because it has less restrictive assumptions and allows unequal variances. The current study examined dEBC measured with electromyography in a single-cue tone paradigm in an age-matched sample of schizophrenia participants and healthy controls (N = 56 per group) using HLM. Subjects participated in 90 trials (10 blocks) of dEBC, during which a 400 ms tone co-terminated with a 50 ms air puff delivered to the left eye. Each block also contained 1 tone-alone trial. The resulting block averages of dEBC data were fitted to a three-parameter logistic model in HLM, revealing significant differences between schizophrenia and control groups on asymptote and inflection point, but not slope. These findings suggest that while the learning rate is not significantly different compared to controls, associative learning begins to level off later and a lower ultimate level of associative learning is achieved in schizophrenia. Given the large sample size in the present study, HLM may provide a more nuanced and definitive analysis of differences between schizophrenia and controls on dEBC.

  17. Classical conditioning of the eyeblink reflex in the decerebrate-decerebellate rabbit.

    PubMed

    Kelly, T M; Zuo, C C; Bloedel, J R

    1990-04-16

    The purpose of these experiments was to test the hypothesis that a conditioned nictitating membrane reflex can be acquired in decerebrate rabbits in the absence of the cerebellum. Experiments examining the effects of large cerebellar lesions on the acquisition and performance of the conditioned reflex were performed in acutely prepared decerebrate rabbits. Most lesions encompassed all of the cerebellar nuclear regions ipsilateral to the eye receiving the unconditioned stimulus. In all rabbits included in this study the continuity between the cerebellar nuclei and the brainstem was interrupted, even in those preparations in which small regions of the nuclei were present in the lateral hemisphere. The findings demonstrate that these animals could acquire the conditioned reflex independent of whether conditioning had occurred prior to the cerebellectomy. Strong associativity was found between the latency of the conditioned response and the interstimulus interval between the conditioned and unconditioned stimuli. The behavior of the conditioned reflex observed in the decerebrate-decerebellate animals differed from that reported for awake intact rabbits in two ways. Once the conditioned behavior had been acquired, the percent of trials showing conditioned responses was somewhat less in decerebrate-decerebellate rabbits and was also more variable in these animals. The data demonstrate that the nictitating membrane reflex can be classically conditioned in the absence of the cerebellum, indicating that this structure is neither necessary nor sufficient for the acquisition of this type of conditioned behavior. In addition, an hypothesis is presented which addresses the difference between the data reported here and those previously reported by other laboratories based on observations in awake intact animals.

  18. GABAergic neurons in the medial septum-diagonal band of Broca (MSDB) are important for acquisition of the classically conditioned eyeblink response.

    PubMed

    Roland, J J; Janke, K L; Servatius, R J; Pang, K C H

    2014-07-01

    The medial septum and diagonal band of Broca (MSDB) influence hippocampal function through cholinergic, GABAergic, and glutamatergic septohippocampal neurons. Non-selective damage of the MSDB or intraseptal scopolamine impairs classical conditioning of the eyeblink response (CCER). Scopolamine preferentially inhibits GABAergic MSDB neurons suggesting that these neurons may be an important modulator of delay CCER, a form of CCER not dependent on the hippocampus. The current study directly examined the importance of GABAergic MSDB neurons in acquisition of delay CCER. Adult male Sprague-Dawley rats received either a sham (PBS) or GABAergic MSDB lesion using GAT1-saporin (SAP). Rats were given two consecutive days of delay eyeblink conditioning with 100 conditioned stimulus-unconditioned stimulus paired trials. Intraseptal GAT1-SAP impaired acquisition of CCER. The impairment was observed on the first day with sham and lesion groups reaching similar performance by the end of the second day. Our results provide evidence that GABAergic MSDB neurons are an important modulator of delay CCER. The pathways by which MSDB neurons influence the neural circuits necessary for delay CCER are discussed.

  19. Children with Specific Language Impairment are not impaired in the acquisition and retention of Pavlovian delay and trace conditioning of the eyeblink response☆

    PubMed Central

    Hardiman, Mervyn J.; Hsu, Hsin-jen; Bishop, Dorothy V.M.

    2013-01-01

    Three converging lines of evidence have suggested that cerebellar abnormality is implicated in developmental language and literacy problems. First, some brain imaging studies have linked abnormalities in cerebellar grey matter to dyslexia and specific language impairment (SLI). Second, theoretical accounts of both dyslexia and SLI have postulated impairments of procedural learning and automatisation of skills, functions that are known to be mediated by the cerebellum. Third, motor learning has been shown to be abnormal in some studies of both disorders. We assessed the integrity of face related regions of the cerebellum using Pavlovian eyeblink conditioning in 7–11 year-old children with SLI. We found no relationship between oral language skills or literacy skills with either delay or trace conditioning in the children. We conclude that this elementary form of associative learning is intact in children with impaired language or literacy development. PMID:24139661

  20. Children with specific language impairment are not impaired in the acquisition and retention of Pavlovian delay and trace conditioning of the eyeblink response.

    PubMed

    Hardiman, Mervyn J; Hsu, Hsin-jen; Bishop, Dorothy V M

    2013-12-01

    Three converging lines of evidence have suggested that cerebellar abnormality is implicated in developmental language and literacy problems. First, some brain imaging studies have linked abnormalities in cerebellar grey matter to dyslexia and specific language impairment (SLI). Second, theoretical accounts of both dyslexia and SLI have postulated impairments of procedural learning and automatisation of skills, functions that are known to be mediated by the cerebellum. Third, motor learning has been shown to be abnormal in some studies of both disorders. We assessed the integrity of face related regions of the cerebellum using Pavlovian eyeblink conditioning in 7-11year-old children with SLI. We found no relationship between oral language skills or literacy skills with either delay or trace conditioning in the children. We conclude that this elementary form of associative learning is intact in children with impaired language or literacy development. Copyright © 2013 The Authors. Published by Elsevier Inc. All rights reserved.

  1. Effects of OEF/OIF-Related Physical and Emotional Co-Morbidities on Associative Learning: Concurrent Delay and Trace Eyeblink Classical Conditioning

    PubMed Central

    McGlinchey, Regina E.; Fortier, Catherine B.; Venne, Jonathan R.; Maksimovskiy, Arkadiy L.; Milberg, William P.

    2014-01-01

    This study examined the performance of veterans and active duty personnel who served in Operation Enduring Freedom and/or Operation Iraqi Freedom (OEF/OIF) on a basic associative learning task. Eighty-eight individuals participated in this study. All received a comprehensive clinical evaluation to determine the presence and severity of posttraumatic stress disorder (PTSD) and traumatic brain injury (TBI). The eyeblink conditioning task was composed of randomly intermixed delay and trace conditioned stimulus (CS) and unconditioned stimulus (US) pairs (acquisition) followed by a series of CS only trials (extinction). Results revealed that those with a clinical diagnosis of PTSD or a diagnosis of PTSD with comorbid mTBI acquired delay and trace conditioned responses (CRs) to levels and at rates similar to a deployed control group, thus suggesting intact basic associative learning. Differential extinction impairment was observed in the two clinical groups. Acquisition of CRs for both delay and trace conditioning, as well as extinction of trace CRs, was associated with alcoholic behavior across all participants. These findings help characterize the learning and memory function of individuals with PTSD and mTBI from OEF/OIF and raise the alarming possibility that the use of alcohol in this group may lead to more significant cognitive dysfunction. PMID:24625622

  2. Pronounced reduction of acquisition of conditioned eyeblink responses in young adults with focal cerebellar lesions impedes conclusions on the role of the cerebellum in extinction and savings.

    PubMed

    Ernst, T M; Beyer, L; Mueller, O M; Göricke, S; Ladd, M E; Gerwig, M; Timmann, D

    2016-05-01

    Human cerebellar lesion studies provide good evidence that the cerebellum contributes to the acquisition of classically conditioned eyeblink responses (CRs). As yet, only one study used more advanced methods of lesion-symptom (or lesion-behavior) mapping to investigate which cerebellar areas are involved in CR acquisition in humans. Likewise, comparatively few studies investigated the contribution of the human cerebellum to CR extinction and savings. In this present study, young adults with focal cerebellar disease were tested. A subset of participants was expected to acquire enough conditioned responses to allow the investigation of extinction and saving effects. 19 participants with chronic surgical lesions of the cerebellum and 19 matched control subjects were tested. In all cerebellar subjects benign tumors of the cerebellum had been surgically removed. Eyeblink conditioning was performed using a standard short delay protocol. An initial unpaired control phase was followed by an acquisition phase, an extinction phase and a subsequent reacquisition phase. Structural 3T magnetic resonance images of the brain were acquired on the day of testing. Cerebellar lesions were normalized using methods optimized for the cerebellum. Subtraction analysis and Liebermeister tests were used to perform lesion-symptom mapping. As expected, CR acquisition was significantly reduced in cerebellar subjects compared to controls. Reduced CR acquisition was significantly more likely in participants with lesions of lobule VI and Crus I extending into Crus II (p<0.05, Liebermeister test). Cerebellar subjects could be subdivided into two groups: a smaller group (n=5) which showed acquisition, extinction and savings within the normal range; and a larger group (n=14) which did not show acquisition. In the latter, no conclusions on extinction or savings could be drawn. Previous findings were confirmed that circumscribed areas in lobule VI and Crus I are of major importance in CR acquisition

  3. Dynamic Elbow Flexion Force Estimation Through a Muscle Twitch Model and sEMG in a Fatigue Condition.

    PubMed

    Na, Youngjin; Kim, Jung

    2016-11-14

    We propose a joint force estimation method to compute elbow flexion force using surface electromyogram (sEMG) considering time-varying effects in a fatigue condition. Muscle fatigue is a major cause inducing sEMG changes with respect to time over long periods and repetitive contractions. The proposed method composed the muscle-twitch model representing the force generated by a single spike and the spikes extracted from sEMG. In this study, isometric contractions at six different joint angles (ten subjects) and dynamic contractions with constant velocity (six subjects) were performed under non-fatigue and fatigue conditions. Performance of the proposed method was evaluated and compared with that of previous methods using mean absolute value (MAV). The proposed method achieved average 6.7±2.8 %RMSE for isometric contraction and 15.6±24.7 %RMSE for isokinetic contraction under fatigue condition with more accurate results than the previous methods.

  4. Characteristics of spontaneous eyeblink activity during video display terminal use in healthy volunteers.

    PubMed

    Freudenthaler, Nora; Neuf, Hartmut; Kadner, Gregor; Schlote, Torsten

    2003-11-01

    To analyse the spontaneous eyeblink rate (SEBR) and inter-eyeblink intervals (IEBI) of normal volunteers before and during video display terminal (VDT) use. The SEBR of 51 normal volunteers was measured by counting the absence of the corneal reflex using a computer-based video analysis system. Only complete eyeblinks were recorded within 10 min under three different conditions: during a conversation, during VDT use without corneal anaesthesia, and during VDT use with corneal anaesthesia. The IEBI (in seconds) were determined to study individual time-dependent changes of SEBR. In comparison with SEBR during conversation (mean 15.54 eyeblinks/min, standard deviation +/-13.74 eyeblinks/min) the SEBR decreased significantly during VDT use without corneal anaesthesia (5.34 +/- 4.53 eyeblinks/min). Corneal anaesthesia further significantly reduced SEBR (2.78 +/- 2.77 eyeblinks/min). The SEBR was characterized by marked interindividual variability, ranging between 11 and 664 eyeblinks/10 min during conversation, between 4 and 189 eyeblinks during VDT use without corneal anaesthesia and between 1 and 119 eyeblinks at VDT use with corneal anaesthesia. No significant correlation between SEBR (during conversation or during VDT use) and quality (break-up time) or quantity (Schirmer I test, Jones test) of the tear film could be detected. Evaluation of the IEBI revealed three different types of eyeblink pattern during VDT use without corneal anaesthesia. Type 1 was characterized by a very low SEBR (0-2 eyeblinks/min) and relatively homogeneous distribution of eyeblinks, type 2 showed a moderate SEBR (1.2-8.5 eyeblinks/min) including three further subtypes. Type 3 was characterized by a high SEBR (6.8-18.9 eyeblinks/min) of regular or irregular pattern. VDT use is associated with a profound decrease of the SEBR in healthy subjects. There are marked interindividual differences in SEBR and no correlation between the SEBR and ocular tear film parameters in normal eyes. The SEBR is

  5. Knee angle-specific MVIC for triceps surae EMG signal normalization in weight and non weight-bearing conditions.

    PubMed

    Hébert-Losier, Kim; Holmberg, Hans-Christer

    2013-08-01

    Varying the degree of weight-bearing (WB) and/or knee flexion (KF) angle during a plantar-flexion maximal voluntary isometric contraction (MVIC) has been proposed to alter soleus and/or gastrocnemius medialis and lateralis activation. This study compared the surface EMG signals from the triceps surae of 27 men and 27 women during WB and non weight bearing (NWB) plantar-flexion MVICs performed at 0° and 45° of KF. The aim was to determine which condition was most effective at eliciting the greatest EMG signals from soleus, gastrocnemius medialis, and gastrocnemius lateralis, respectively, for subsequent use for the normalization of EMG signals. WB was more effective than NWB at eliciting the greatest signals from soleus (p=0.0021), but there was no difference with respect to gastrocnemius medialis and lateralis (p⩾0.2482). Although the greatest EMG signals during MVICs were more frequently elicited at 0° of KF from gastrocnemius medialis and lateralis, and at 45° from soleus (p<0.001); neither angle consistently captured peak gastrocnemius medialis, gastrocnemius lateralis or soleus activity. The present findings encourage more consistent use of WB plantar flexion MVICs for soleus normalization; confirm that both WB and NWB procedures can elicit peak gastrocnemius activity; and emphasize the fact that no single KF angle consistently evokes selective maximal activity of any individual triceps surae muscle.

  6. Probing Prejudice with Startle Eyeblink Modification: A Marker of Attention, Emotion, or Both?

    PubMed Central

    Vanman, Eric J.; Ryan, John P.; Pedersen, William C.; Ito, Tiffany A.

    2015-01-01

    In social neuroscience research, startle eyeblink modification can serve as a marker of emotion, but it is less clear whether it can also serve as a marker of prejudice. In Experiment 1, 30 White students viewed photographs of White and Black targets while the startle eyeblink reflex and facial EMG from the brow and cheek regions were recorded. Prejudice was related to facial EMG activity, but not to startle modification, which instead appeared to index attention to race. To test further whether racial categorizations are associated with differential attention, a dual-task paradigm was used in Experiment 2. Fifty-four White and fifty-five Black participants responded more slowly to a tone presented when viewing a racial outgroup member or a negative stimulus, indicating that both draw more attention than ingroup members or positive stimuli. We conclude that startle modification is useful to index differential attention to groups when intergroup threat is low. PMID:26023325

  7. Conditioning and sampling issues of EMG signals in motion recognition of multifunctional myoelectric prostheses.

    PubMed

    Li, Guanglin; Li, Yaonan; Yu, Long; Geng, Yanjuan

    2011-06-01

    Historically, the investigations of electromyography (EMG) pattern recognition-based classification of intentional movements for control of multifunctional prostheses have adopted the filter cut-off frequency and sampling rate that are commonly used in EMG research fields. In practical implementation of a multifunctional prosthesis control, it is desired to have a higher high-pass cut-off frequency to reduce more motion artifacts and to use a lower sampling rate to save the data processing time and memory of the prosthesis controller. However, it remains unclear whether a high high-pass cut-off frequency and a low-sampling rate still preserve sufficient neural control information for accurate classification of movements. In this study, we investigated the effects of high-pass cut-off frequency and sampling rate on accuracy in identifying 11 classes of arm and hand movements in both able-bodied subjects and arm amputees. Compared to a 5-Hz high-pass cut-off frequency, excluding the EMG components below 60 Hz decreased the average accuracy of 0.1% in classifying the 11 movements across able-bodied subjects and increased the average accuracy of 0.1 and 0.4% among the transradial (TR) and shoulder disarticulation (SD) amputees, respectively. Using a 500 Hz instead of a 1-kHz sampling rate, the average classification accuracy only dropped about 2.0% in arm amputees. The combination of sampling rate and high-pass cut-off frequency of 500 and 60 Hz only resulted in about 2.3% decrease in average accuracy for TR amputees and 0.4% decrease for SD amputees in comparison to the generally used values of 1 kHz and 5 Hz. These results suggest that the combination of sampling rate of 500 Hz and high-pass cut-off frequency of 60 Hz should be an optimal selection in EMG recordings for recognition of different arm movements without sacrificing too much of classification accuracy which can also remove most of motion artifacts and power-line interferences for improving the

  8. Detecting deception via eyeblink frequency modulation

    PubMed Central

    2014-01-01

    To assess the efficacy of using eyeblink frequency modulation to detect deception about a third party, 32 participants were sent on a mission to deliver a package to an interviewer. 17 of the participants lied to the interviewer about the details of their mock mission and 15 responded truthfully. During the interview, eyeblink frequency data were collected via electromyography and recorded video. Liars displayed eyeblink frequency suppression while lying, while truth tellers exhibited an increase in eyeblink frequency during the mission relevant questioning period. The compensatory flurry of eyeblinks following deception observed in previous studies was absent in the present study. A discriminant function using eyeblink suppression to predict lying correctly classified 81.3% of cases, with a sensitivity of 88.2% and a specificity of 73.3%. This technique, yielding a reasonable sensitivity, shows promise for future testing as, unlike polygraph, it is compatible with distance technology. PMID:24688844

  9. An Investigative Redesign of the ECG and EMG Signal Conditioning Circuits for Two-fault Tolerance and Circuit Improvement

    NASA Technical Reports Server (NTRS)

    Obrien, Edward M.

    1991-01-01

    An investigation was undertaken to make the elctrocardiography (ECG) and the electromyography (EMG) signal conditioning circuits two-fault tolerant and to update the circuitry. The present signal conditioning circuits provide at least one level of subject protection against electrical shock hazard but at a level of 100 micro-A (for voltages of up to 200 V). However, it is necessary to provide catastrophic fault tolerance protection for the astronauts and to provide protection at a current level of less that 100 micro-A. For this study, protection at the 10 micro-A level was sought. This is the generally accepted value below which no possibility of microshock exists. Only the possibility of macroshock exists in the case of the signal conditioners. However, this extra amount of protection is desirable. The initial part deals with current limiter circuits followed by an investigation into the signal conditioner specifications and circuit design.

  10. Eyeblink entrainment at breakpoints of speech.

    PubMed

    Nakano, Tamami; Kitazawa, Shigeru

    2010-09-01

    The eyes play an essential role in social communication. Eyeblinks, however, have thus far received minor attention. We previously showed that subjects blink in synchrony while viewing the same video stories (Nakano et al. in Proc R Soc B 276:3635-3644, 2009). We therefore hypothesized that eyeblinks are synchronized between listener and speaker in face-to-face conversation. Here, we show that listeners blinked with a delay of 0.25-0.5 s after the speaker blinked when the listeners viewed close-up video clips (with sound) of the speaker's face. Furthermore, this entrainment was selectively triggered by speaker's eyeblinks occurring at the end and during pauses in speech. Eyeblink entrainment was not observed when viewing identical video clips without sound, indicating that blink entrainment was not an automatic imitation. We therefore suggest that eyeblink entrainment reflects smooth communication between interactants.

  11. Neonatal ethanol exposure results in dose-dependent impairments in the acquisition and timing of the conditioned eyeblink response and altered cerebellar interpositus nucleus and hippocampal CA1 unit activity in adult rats

    PubMed Central

    Lindquist, Derick H.; Sokoloff, Greta; Milner, Eric; Steinmetz, Joseph E.

    2013-01-01

    Exposure to ethanol in neonatal rats results in reduced neuronal numbers in the cerebellar cortex and deep nuclei of juvenile and adult animals. This reduction in cell numbers is correlated with impaired delay eyeblink conditioning (EBC), a simple motor learning task in which a neutral conditioned stimulus (CS; tone) is repeatedly paired with a co-terminating unconditioned stimulus (US; periorbital shock). Across training, cell populations in the interpositus (IP) nucleus model the temporal form of the eyeblink conditioned response (CR). The hippocampus, though not required for delay EBC, also shows learning-dependent increases in CA1 and CA3 unit activity. In the present study, rat pups were exposed to 0, 3, 4, or 5 mg/kg/day of ethanol during postnatal days (PD) 4–9. As adults, CR acquisition and timing were assessed during 6 training sessions of delay EBC with a short (280 msec) interstimulus interval (ISI; time from CS onset to US onset) followed by another 6 sessions with a long (880 msec) ISI. Neuronal activity was recorded in the IP and area CA1 during all 12 sessions. The high-dose rats learned the most slowly and, with the moderate-dose rats, produced the longest CR peak latencies over training to the short ISI. The low dose of alcohol impaired CR performance to the long ISI only. The 3E (3 mg/kg/day of ethanol) and 5E (5 mg/kg/day of ethanol) rats also showed slower-than-normal increases in learning-dependent excitatory unit activity in the IP and CA1. The 4E (4 mg/kg/day of ethanol) rats showed a higher rate of CR production to the long ISI and enhanced IP and CA1 activation when compared to the 3E and 5E rats. The results indicate that binge-like ethanol exposure in neonatal rats induces long-lasting, dose-dependent deficits in CR acquisition and timing and diminishes conditioning-related neuronal excitation in both the cerebellum and hippocampus. PMID:23871534

  12. Neonatal ethanol exposure results in dose-dependent impairments in the acquisition and timing of the conditioned eyeblink response and altered cerebellar interpositus nucleus and hippocampal CA1 unit activity in adult rats.

    PubMed

    Lindquist, Derick H; Sokoloff, Greta; Milner, Eric; Steinmetz, Joseph E

    2013-09-01

    Exposure to ethanol in neonatal rats results in reduced neuronal numbers in the cerebellar cortex and deep nuclei of juvenile and adult animals. This reduction in cell numbers is correlated with impaired delay eyeblink conditioning (EBC), a simple motor learning task in which a neutral conditioned stimulus (CS; tone) is repeatedly paired with a co-terminating unconditioned stimulus (US; periorbital shock). Across training, cell populations in the interpositus (IP) nucleus model the temporal form of the eyeblink-conditioned response (CR). The hippocampus, though not required for delay EBC, also shows learning-dependent increases in CA1 and CA3 unit activity. In the present study, rat pups were exposed to 0, 3, 4, or 5 mg/kg/day of ethanol during postnatal days (PD) 4-9. As adults, CR acquisition and timing were assessed during 6 training sessions of delay EBC with a short (280 ms) interstimulus interval (ISI; time from CS onset to US onset) followed by another 6 sessions with a long (880 ms) ISI. Neuronal activity was recorded in the IP and area CA1 during all 12 sessions. The high-dose rats learned the most slowly and, with the moderate-dose rats, produced the longest CR peak latencies over training to the short ISI. The low dose of alcohol impaired CR performance to the long ISI only. The 3E (3 mg/kg/day of ethanol) and 5E (5 mg/kg/day of ethanol) rats also showed slower-than-normal increases in learning-dependent excitatory unit activity in the IP and CA1. The 4E (4 mg/kg/day of ethanol) rats showed a higher rate of CR production to the long ISI and enhanced IP and CA1 activation when compared to the 3E and 5E rats. The results indicate that binge-like ethanol exposure in neonatal rats induces long-lasting, dose-dependent deficits in CR acquisition and timing and diminishes conditioning-related neuronal excitation in both the cerebellum and hippocampus.

  13. Fear-potentiated startle processing in humans: Parallel fMRI and orbicularis EMG assessment during cue conditioning and extinction.

    PubMed

    Lindner, Katja; Neubert, Jörg; Pfannmöller, Jörg; Lotze, Martin; Hamm, Alfons O; Wendt, Julia

    2015-12-01

    Studying neural networks and behavioral indices such as potentiated startle responses during fear conditioning has a long tradition in both animal and human research. However, most of the studies in humans do not link startle potentiation and neural activity during fear acquisition and extinction. Therefore, we examined startle blink responses measured with electromyography (EMG) and brain activity measured with functional MRI simultaneously during differential conditioning. Furthermore, we combined these behavioral fear indices with brain network activity by analyzing the brain activity evoked by the startle probe stimulus presented during conditioned visual threat and safety cues as well as in the absence of visual stimulation. In line with previous research, we found a fear-induced potentiation of the startle blink responses when elicited during a conditioned threat stimulus and a rapid decline of amygdala activity after an initial differentiation of threat and safety cues in early acquisition trials. Increased activation during processing of threat cues was also found in the anterior insula, the anterior cingulate cortex (ACC), and the periaqueductal gray (PAG). More importantly, our results depict an increase of brain activity to probes presented during threatening in comparison to safety cues indicating an involvement of the anterior insula, the ACC, the thalamus, and the PAG in fear-potentiated startle processing during early extinction trials. Our study underlines that parallel assessment of fear-potentiated startle in fMRI paradigms can provide a helpful method to investigate common and distinct processing pathways in humans and animals and, thus, contributes to translational research.

  14. A long-range, wide field-of-view infrared eyeblink detector.

    PubMed

    Ryan, Steven B; Detweiler, Krystal L; Holland, Kyle H; Hord, Michael A; Bracha, Vlastislav

    2006-04-15

    Classical conditioning of the eyeblink response in the rabbit is one of the most advanced models of learning and memory in the mammalian brain. Successful use of the eyeblink conditioning paradigm requires precise measurements of the eyeblink response. One common technique of eyelid movement detection utilizes measurements of infrared (IR) light reflected from the surface of the eye. The performance of current IR sensors, however, is limited by their sensitivity to ambient infrared noise, by their small field-of-view and by short working distances. To address these limitations, we developed an IR eyeblink detector consisting of a pulsing (62.5 kHz) IR light emitting diode (LED) paired with a silicon IR photodiode and circuit that synchronously demodulates the recorded signal and rejects background IR noise. The working distance of the sensor exceeds 20 mm, and the field-of-view is larger than the area of a rabbit's eye. Due to its superior characteristics, the new sensor is ideally suited for both standard eyeblink conditioning and for studies that utilize IR-containing visual stimuli and/or that are conducted in an environment contaminated with IR noise.

  15. Contributions of facial morphology, age, and gender to EMG activity under biting and resting conditions: a canonical correlation analysis.

    PubMed

    Fogle, L L; Glaros, A G

    1995-08-01

    Theoretical studies suggest that facial morphology may confer a mechanical advantage to particular individuals during force production, but not during rest. However, prior studies on the relationship between facial morphology and EMG suffer from various methodological limitations. We examined the hypothesis that facial morphology variables contribute significantly and meaningfully to the variance in masticatory muscle EMG when subjects produce specific levels of interocclusal force, but not when subjects are at rest. Measures of facial morphology included gonial angle, ramus height, and maxillary height, as determined from lateral cephalograms. EMG data were obtained from surface electrodes placed on masseter and temporalis sites. Subjects (N = 96) sat in a darkened, sound-attenuated room while they watched a seven-minute segment of a movie. EMG activity obtained during the last two minutes was used as a baseline period. Using the central incisors, subjects then provided five different force levels ranging from 6.5 to 48 lb in random order on a bite-force device while EMG data were collected. A canonical correlation analysis, performed on the set of predictor variables (age, gender, and facial morphology measurements) and the set of criterion variables (EMG data), showed a significant canonical correlation between the two variable sets while biting, but not at rest. Age, but not the facial morphology variables, was highly related to the canonical variate.(ABSTRACT TRUNCATED AT 250 WORDS)

  16. Sensitivity of EMG-EMG coherence to detect the common oscillatory drive to hand muscles in young and older adults.

    PubMed

    Keenan, Kevin G; Massey, William V; Walters, Tygh J; Collins, Joseph D

    2012-05-01

    Multichannel surface electromyograms (EMGs) were used to examine the sensitivity of EMG-EMG coherence to infer changes in common oscillatory drive to hand muscles in young and older adults. Previous research has shown that measures of coherence calculated from different neurophysiological signals are influenced by the age of the subject, the visual feedback provided to the subject, and the task being performed. The change in the magnitude of EMG-EMG coherence across experimental conditions is often interpreted as a change in the oscillatory drive to motoneuron pools of a pair of muscles. However, signal processing (e.g., full-wave rectification) and electrode location are also reported to influence EMG-EMG coherence, which could decrease the sensitivity of EMG-EMG coherence to infer a change in common oscillatory drive to motoneurons. In this study, multichannel EMGs were used to compare EMG-EMG coherence in young (n = 11) and older (n = 10) adults during index finger abduction and pinch grip tasks performed at 2 and 3.5 N with a low and a high visual feedback gain. We found that, across all conditions, EMG-EMG coherence was influenced by electrode location (P < 0.001) but not by subject age, visual feedback gain, task, or signal processing. These results suggest that EMG-EMG coherence is most sensitive to electrode location. The results are discussed in terms of the potential issues related to inferring a common oscillatory drive to hand muscles with surface EMGs.

  17. The search for the engram in eyeblink conditioning: A synopsis of past and present perspectives on the role of the cerebellum.

    PubMed

    Foy, Michael R; Foy, Judith G

    2016-12-01

    One of the most prolific behavioral neuroscientists of his generation, Richard F. Thompson published more than 450 research articles during his almost 60-year career before his death in 2014. The breadth and reach of his scholarship has extended to a large multidisciplinary audience of scientists. The focal point of this article is arguably his most influential paper on cerebellar classical conditioning entitled "The Neurobiology of Learning and Memory" that appeared in Science in 1986 and has been cited 700 times since its publication. Here, a summary of the initial Thompson laboratory research leading up to an understanding of the cerebellum and its critical role in memory traces will be discussed, along with conclusions from the Science article pertinent to cerebellar classical conditioning. The summary will also discuss how the original 1986 article continues to stimulate and influence new research and provide further insights into the role of the cerebellum in the neurobiology of learning and memory function relevant to studies of mammalian classical conditioning. (PsycINFO Database Record

  18. The rostral medial prefrontal cortex regulates the expression of conditioned eyelid responses in behaving rabbits.

    PubMed

    Leal-Campanario, Rocío; Delgado-García, José M; Gruart, Agnès

    2013-03-06

    We studied the contribution of the rostral mPFC (rmPFC) to the acquisition and performance of classical eyeblink conditioning in rabbits using a delay paradigm. The rmPFC was determined by its afferent projections from the medial half of the mediodorsal thalamic nucleus. The rmPFC neurons were identified by their antidromic activation from the mediodorsal nucleus and/or by their firing characteristics. The rmPFC neurons increased their firing during the first conditioning sessions, but decreased it when conditioned responses (CRs) reached asymptotic values. Therefore, no significant relationships could be established between neuronal firing rates and the percentage of CRs or the electromyographic (EMG) activity of the orbicularis oculi muscle during conditioning. Electrical train stimulation of the rmPFC produced a significant inhibition of air-puff-evoked blinks and reduced the generation of CRs compared with controls. Inhibition of the rmPFC by the local injection of lidocaine produced an increase in the amplitude of evoked reflex and conditioned eyeblinks and in the percentage of CRs. The rmPFC seems to be a potent inhibitor of reflex and conditioned eyeblinks, controlling the release of newly acquired eyelid responses until advanced stages of the acquisition process--i.e., until the need for the acquired response is fully confirmed. Therefore, the rmPFC seems to act as a "flip-flop" mechanism in controlling behavior.

  19. Lack of eyeblink entrainments in autism spectrum disorders.

    PubMed

    Nakano, Tamami; Kato, Nobumasa; Kitazawa, Shigeru

    2011-07-01

    Interpersonal synchrony is the temporal coordination of movements between individuals during social interactions. For example, it has been shown that listeners synchronize their eyeblinks to a speaker's eyeblinks, especially at breakpoints of speech, when viewing a close-up video clip of the speaker's face. We hypothesized that this interpersonal synchronous behavior would not be observed in individuals with autism spectrum disorders (ASD), which are characterized by impaired social communication. To test this hypothesis, we examined eyeblink entrainments in adults with ASD. As we reported previously, the eyeblinks of adults without ASD were significantly synchronized with the speaker's eyeblinks at pauses in his speech when they viewed the speaker's entire face. However, the significant eyeblink synchronization disappeared when adults without ASD viewed only the speaker's eyes or mouth, suggesting that information from the whole face, including information from both the eyes and the mouth, was necessary for eyeblink entrainment. By contrast, the ASD participants did not show any eyeblink synchronization with the speaker, even when viewing the speaker's eyes and mouth simultaneously. The lack of eyeblink entrainment to the speaker in individuals with ASD suggests that they are not able to temporally attune themselves to others' behaviors. The deficits in temporal coordination may impair effective social communication with others.

  20. Spontaneous Eyeblinks Are Correlated with Responses during the Stroop Task

    PubMed Central

    Oh, Jihoon; Han, Mookyung; Peterson, Bradley S.; Jeong, Jaeseung

    2012-01-01

    The timing and frequency of spontaneous eyeblinking is thought to be influenced by ongoing internal cognitive or neurophysiological processes, but how precisely these processes influence the dynamics of eyeblinking is still unclear. This study aimed to better understand the functional role of eyeblinking during cognitive processes by investigating the temporal pattern of eyeblinks during the performance of attentional tasks. The timing of spontaneous eyeblinks was recorded from 28 healthy subjects during the performance of both visual and auditory versions of the Stroop task, and the temporal distributions of eyeblinks were estimated in relation to the timing of stimulus presentation and vocal response during the tasks. We found that the spontaneous eyeblink rate increased during Stroop task performance compared with the resting rate. Importantly, the subjects (17/28 during the visual Stroop, 20/28 during the auditory Stroop) were more likely to blink before a vocal response in both tasks (150–250 msec) and the remaining subjects were more likely to blink soon after the vocal response (200–300 msec), regardless of the stimulus type (congruent or incongruent) or task difficulty. These findings show that spontaneous eyeblinks are closely associated with responses during the performance of the Stroop task on a short time scale and suggest that spontaneous eyeblinks likely signal a shift in the internal cognitive or attentional state of the subjects. PMID:22493720

  1. H-REFLEX UP-CONDITIONING ENCOURAGES RECOVERY OF EMG ACTIVITY AND H-REFLEXES AFTER SCIATIC NERVE TRANSECTION AND REPAIR IN RATS

    PubMed Central

    Chen, Yi; Wang, Yu; Chen, Lu; Sun, Chenyuo; English, Arthur W.; Wolpaw, Jonathan R.; Chen, Xiang Yang

    2010-01-01

    Operant conditioning of the spinal stretch reflex or its electrical analog, the H-reflex, produces spinal cord plasticity and can thereby affect motoneuron responses to primary afferent input. To explore whether this conditioning can affect the functional outcome after peripheral nerve injury, we assessed the effect of up-conditioning soleus (SOL) H-reflex on SOL and tibialis anterior (TA) function after sciatic nerve transection and repair. Sprague-Dawley rats were implanted with EMG electrodes in SOL and TA and stimulating cuffs on the posterior tibial nerve. After control data collection, the sciatic nerve was transected and repaired and the rat was exposed for 120 days to continued control data collection (TC rats) or SOL H-reflex up-conditioning (TU rats). At the end of data collection, motoneurons that had reinnervated SOL and TA were labeled retrogradely. Putative primary afferent terminals (i.e., terminals containing vesicular glutamate transporter-1 (VGLUT1)) on SOL motoneurons were studied immunohistochemically. SOL (and probably TA) background EMG activity recovered faster in TU rats than in TC rats, and the final recovered SOL H-reflex was significantly larger in TU than in TC rats. TU and TC rats had significantly fewer labeled motoneurons and higher proportions of double-labeled motoneurons than untransected rats. VGLUT1 terminals were significantly more numerous on SOL motoneurons of TU than TC rats. Combined with the larger H-reflexes in TU rats, this anatomical finding supports the hypothesis that SOL H-reflex up-conditioning strengthened primary afferent reinnervation of SOL motoneurons. These results suggest that H-reflex up-conditioning may improve functional recovery after nerve injury and repair. PMID:21123559

  2. H-reflex up-conditioning encourages recovery of EMG activity and H-reflexes after sciatic nerve transection and repair in rats.

    PubMed

    Chen, Yi; Wang, Yu; Chen, Lu; Sun, Chenyou; English, Arthur W; Wolpaw, Jonathan R; Chen, Xiang Yang

    2010-12-01

    Operant conditioning of the spinal stretch reflex or its electrical analog, the H-reflex, produces spinal cord plasticity and can thereby affect motoneuron responses to primary afferent input. To explore whether this conditioning can affect the functional outcome after peripheral nerve injury, we assessed the effect of up-conditioning soleus (SOL) H-reflex on SOL and tibialis anterior (TA) function after sciatic nerve transection and repair. Sprague Dawley rats were implanted with EMG electrodes in SOL and TA and stimulating cuffs on the posterior tibial nerve. After control data collection, the sciatic nerve was transected and repaired and the rat was exposed for 120 d to continued control data collection (TC rats) or SOL H-reflex up-conditioning (TU rats). At the end of data collection, motoneurons that had reinnervated SOL and TA were labeled retrogradely. Putative primary afferent terminals [i.e., terminals containing vesicular glutamate transporter-1 (VGLUT1)] on SOL motoneurons were studied immunohistochemically. SOL (and probably TA) background EMG activity recovered faster in TU rats than in TC rats, and the final recovered SOL H-reflex was significantly larger in TU than in TC rats. TU and TC rats had significantly fewer labeled motoneurons and higher proportions of double-labeled motoneurons than untransected rats. VGLUT1 terminals were significantly more numerous on SOL motoneurons of TU than TC rats. Combined with the larger H-reflexes in TU rats, this anatomical finding supports the hypothesis that SOL H-reflex up-conditioning strengthened primary afferent reinnervation of SOL motoneurons. These results suggest that H-reflex up-conditioning may improve functional recovery after nerve injury and repair.

  3. Eyeblink Synchrony in Multimodal Human-Android Interaction.

    PubMed

    Tatsukawa, Kyohei; Nakano, Tamami; Ishiguro, Hiroshi; Yoshikawa, Yuichiro

    2016-12-23

    As the result of recent progress in technology of communication robot, robots are becoming an important social partner for humans. Behavioral synchrony is understood as an important factor in establishing good human-robot relationships. In this study, we hypothesized that biasing a human's attitude toward a robot changes the degree of synchrony between human and robot. We first examined whether eyeblinks were synchronized between a human and an android in face-to-face interaction and found that human listeners' eyeblinks were entrained to android speakers' eyeblinks. This eyeblink synchrony disappeared when the android speaker spoke while looking away from the human listeners but was enhanced when the human participants listened to the speaking android while touching the android's hand. These results suggest that eyeblink synchrony reflects a qualitative state in human-robot interactions.

  4. Eyeblink Synchrony in Multimodal Human-Android Interaction

    PubMed Central

    Tatsukawa, Kyohei; Nakano, Tamami; Ishiguro, Hiroshi; Yoshikawa, Yuichiro

    2016-01-01

    As the result of recent progress in technology of communication robot, robots are becoming an important social partner for humans. Behavioral synchrony is understood as an important factor in establishing good human-robot relationships. In this study, we hypothesized that biasing a human’s attitude toward a robot changes the degree of synchrony between human and robot. We first examined whether eyeblinks were synchronized between a human and an android in face-to-face interaction and found that human listeners’ eyeblinks were entrained to android speakers’ eyeblinks. This eyeblink synchrony disappeared when the android speaker spoke while looking away from the human listeners but was enhanced when the human participants listened to the speaking android while touching the android’s hand. These results suggest that eyeblink synchrony reflects a qualitative state in human-robot interactions. PMID:28009014

  5. The effect of visual field condition on kinetic in upper extremities and e.m.g in lower extremities while performing reaching in normal adults

    PubMed Central

    Park, Hyekang; Kang, Youngeun; Yoo, Minah; Lee, Bomjin; Yang, Jeongok; Lee, Joongsook; Han, Dongwook; Oh, Taeyoung

    2017-01-01

    [Purpose] The aims of this study was to investigate mean velocity and angle of shoulder joint, activation of tibialis anterior and gastrocnemius according to both eyes, dominant eye and non-dominant eye condition during reaching task in normal adults. [Subjects and Methods] Our research recruited 24 participants (male 11, female 13) in Silla University. Participants were performed reaching out movement by conditions of both eye, dominants eye, non-dominants eye. The target was placed at 45 degree diagonal direction and distance far away 130% of their arm length. Kinetic analysis of the upper extremities was investigated by QUALISYS 3-dimensional motion analysis system. Muscle activation were measured by EMG during reaching tasks. The collected data were statistically processed using the SPSS for win version 20.0. [Results] There was a significant difference of shoulder joint velocity of flexion, abduction and internal rotation according to visual field condition during reaching tasks. There was no significant difference of shoulder joint angle and muscle activation according to visual field conditions during reaching tasks. [Conclusion] In conclusion, visual field has an influence on shoulder joint velocity. Therefore, the visual field may be to play an important role in reach performance. PMID:28210047

  6. Conditioned fear in adult rats is facilitated by the prior acquisition of a classically conditioned motor response

    PubMed Central

    Lindquist, Derick H.; Mahoney, Luke P.; Steinmetz, Joseph E.

    2010-01-01

    Early in eyeblink classical conditioning, amygdala-dependent fear responding is reported to facilitate acquisition of the cerebellar-dependent eyeblink conditioned response (CR), in accord with the two-process model of conditioning (Konorski, 1967). In the current study, we predicted that the conditioned fear (e.g., freezing) observed during eyeblink conditioning may become autonomous of the eyeblink CR and amenable to further associative modification. Conditioned freezing was assessed during and following Pavlovian fear conditioning in Long-Evans rats that had or had not undergone eight prior sessions of eyeblink conditioning. The amplitude and frequency of the tone conditioned stimulus (CS) was held constant across both forms of conditioning. Following fear conditioning in Experiment 1, freezing to the tone CS, but not the context, was facilitated in rats that previously experienced CS-unconditioned stimulus (US) paired eyeblink conditioning. In Experiment 2, freezing immediately following each fear conditioning trial was enhanced in rats subjected to the antecedent eyeblink conditioning, indicating a faster acquisition rate. Finally, in Experiment 3, faster acquisition was seen only in those rats fear conditioned in the same context used for the prior eyeblink conditioning. Taken together, the data indicate that the conditioned fear associated with the context and CS as a result of eyeblink conditioning can be built upon or strengthened during subsequent learning. PMID:20493273

  7. Wideband EMG telemetry system

    NASA Technical Reports Server (NTRS)

    Rosatino, S. A.; Westbrook, R. M.

    1979-01-01

    Miniature, individual crystal-controlled RF transmitters located in EMG pressure sensors simplifies multichannel EMG telemetry for electronic gait monitoring. Transmitters which are assigned operating frequencies within 174 - 216 MHz band have linear frequency response from 20 - 2000 Hz and operate over range of 15 m.

  8. Wideband EMG telemetry system

    NASA Technical Reports Server (NTRS)

    Rosatino, S. A.; Westbrook, R. M.

    1979-01-01

    Miniature, individual crystal-controlled RF transmitters located in EMG pressure sensors simplifies multichannel EMG telemetry for electronic gait monitoring. Transmitters which are assigned operating frequencies within 174 - 216 MHz band have linear frequency response from 20 - 2000 Hz and operate over range of 15 m.

  9. Modeling startle eyeblink electromyogram to assess fear learning

    PubMed Central

    Khemka, Saurabh; Tzovara, Athina; Gerster, Samuel; Quednow, Boris B.

    2016-01-01

    Abstract Pavlovian fear conditioning is widely used as a laboratory model of associative learning in human and nonhuman species. In this model, an organism is trained to predict an aversive unconditioned stimulus from initially neutral events (conditioned stimuli, CS). In humans, fear memory is typically measured via conditioned autonomic responses or fear‐potentiated startle. For the latter, various analysis approaches have been developed, but a systematic comparison of competing methodologies is lacking. Here, we investigate the suitability of a model‐based approach to startle eyeblink analysis for assessment of fear memory, and compare this to extant analysis strategies. First, we build a psychophysiological model (PsPM) on a generic startle response. Then, we optimize and validate this PsPM on three independent fear‐conditioning data sets. We demonstrate that our model can robustly distinguish aversive (CS+) from nonaversive stimuli (CS‐, i.e., has high predictive validity). Importantly, our model‐based approach captures fear‐potentiated startle during fear retention as well as fear acquisition. Our results establish a PsPM‐based approach to assessment of fear‐potentiated startle, and qualify previous peak‐scoring methods. Our proposed model represents a generic startle response and can potentially be used beyond fear conditioning, for example, to quantify affective startle modulation or prepulse inhibition of the acoustic startle response. PMID:27753123

  10. Modeling startle eyeblink electromyogram to assess fear learning.

    PubMed

    Khemka, Saurabh; Tzovara, Athina; Gerster, Samuel; Quednow, Boris B; Bach, Dominik R

    2017-02-01

    Pavlovian fear conditioning is widely used as a laboratory model of associative learning in human and nonhuman species. In this model, an organism is trained to predict an aversive unconditioned stimulus from initially neutral events (conditioned stimuli, CS). In humans, fear memory is typically measured via conditioned autonomic responses or fear-potentiated startle. For the latter, various analysis approaches have been developed, but a systematic comparison of competing methodologies is lacking. Here, we investigate the suitability of a model-based approach to startle eyeblink analysis for assessment of fear memory, and compare this to extant analysis strategies. First, we build a psychophysiological model (PsPM) on a generic startle response. Then, we optimize and validate this PsPM on three independent fear-conditioning data sets. We demonstrate that our model can robustly distinguish aversive (CS+) from nonaversive stimuli (CS-, i.e., has high predictive validity). Importantly, our model-based approach captures fear-potentiated startle during fear retention as well as fear acquisition. Our results establish a PsPM-based approach to assessment of fear-potentiated startle, and qualify previous peak-scoring methods. Our proposed model represents a generic startle response and can potentially be used beyond fear conditioning, for example, to quantify affective startle modulation or prepulse inhibition of the acoustic startle response. © 2016 The Authors. Psychophysiology published by Wiley Periodicals, Inc. on behalf of Society for Psychophysiological Research.

  11. Eye-Blink Behaviors in 71 Species of Primates

    PubMed Central

    Tada, Hideoki; Omori, Yasuko; Hirokawa, Kumi; Ohira, Hideki; Tomonaga, Masaki

    2013-01-01

    The present study was performed to investigate the associations between eye-blink behaviors and various other factors in primates. We video-recorded 141 individuals across 71 primate species and analyzed the blink rate, blink duration, and “isolated” blink ratio (i.e., blinks without eye or head movement) in relation to activity rhythms, habitat types, group size, and body size factors. The results showed close relationships between three types of eye-blink measures and body size factors. All of these measures increased as a function of body weight. In addition, diurnal primates showed more blinks than nocturnal species even after controlling for body size factors. The most important findings were the relationships between eye-blink behaviors and social factors, e.g., group size. Among diurnal primates, only the blink rate was significantly correlated even after controlling for body size factors. The blink rate increased as the group size increased. Enlargement of the neocortex is strongly correlated with group size in primate species and considered strong evidence for the social brain hypothesis. Our results suggest that spontaneous eye-blinks have acquired a role in social communication, similar to grooming, to adapt to complex social living during primate evolution. PMID:23741522

  12. Analysis of EMG measurements during bicycle pedalling.

    PubMed

    Jorge, M; Hull, M L

    1986-01-01

    Activity of eight leg muscles has been monitored for six test subjects while pedalling a bicycle on rollers in the laboratory. Each electromyogram (EMG) data channel was digitized at a sampling rate of 2 kHz by a minicomputer. Data analysis entailed generating plots of both EMG activity regions and integrated EMG (IEMG). For each test subject, data were recorded for five cases of pedalling conditions. The different pedalling conditions were defined to explore a variety of research hypotheses. This exploration has led to the following conclusions: Muscular activity levels of the quadriceps are influenced by the type of shoes worn and activity levels increase with soft sole shoes as opposed to cycling shoes with cleats and toeclips. EMG activity patterns are not strongly related to pedalling conditions (i.e. load, seat height and shoe type). The level of muscle activity, however, is significantly affected by pedalling conditions. Muscular activity bears a complex relationship with seat height and quadriceps activity level decreases with greater seat height. Agonist (i.e. hamstrings) and antagonist (i.e. quadriceps) muscles of the hip/knee are active simultaneously during leg extension. Regions of peak activity levels, however, do not overlap. The lack of significant cocontraction of agonist/antagonist muscles enables muscle forces during pedalling action to be computed by solving a series of equilibrium problems over different regions of the crank cycle. Regions are defined and a solution procedure is outlined.

  13. Change Mechanisms in EMG Biofeedback Training: Cognitive Changes Underlying Improvements in Tension Headache.

    ERIC Educational Resources Information Center

    Holroyd, Kenneth A.; And Others

    1984-01-01

    Subjects (N=43) suffering from tension headache were assigned to one of four electromyograph (EMG) biofeedback conditions and were led to believe they were achieving high or moderate success in decreasing EMG activity. Regardless of actual EMG changes, subjects receiving high-success feedback showed greater improvement for headaches than…

  14. Change Mechanisms in EMG Biofeedback Training: Cognitive Changes Underlying Improvements in Tension Headache.

    ERIC Educational Resources Information Center

    Holroyd, Kenneth A.; And Others

    1984-01-01

    Subjects (N=43) suffering from tension headache were assigned to one of four electromyograph (EMG) biofeedback conditions and were led to believe they were achieving high or moderate success in decreasing EMG activity. Regardless of actual EMG changes, subjects receiving high-success feedback showed greater improvement for headaches than…

  15. Reliability of EMG normalisation methods for upper-limb muscles.

    PubMed

    Rota, Samuel; Rogowski, Isabelle; Champely, Stéphane; Hautier, Christophe

    2013-01-01

    The study investigated different electromyographic (EMG) normalisation methods for upper-limb muscles. This assessment aimed at comparing the EMG amplitude and the reliability of EMG values obtained with each method. Eighteen male tennis players completed isometric maximal voluntary contractions and dynamic strength exercises (push-ups and chin-ups) on three separate test sessions over at least 7 days. Surface EMG activity of nine upper body muscles was recorded. For each muscle, an analysis of variance for repeated measures was used to compare maximal EMG amplitudes between test conditions. The intra-class correlation coefficient, the coefficient of variation and the standard error of measurement were calculated to determine the EMG reliability of each condition. On the basis of a compromise between maximal EMG amplitude and high reliability, the chin-ups appeared to be the optimal normalisation method for M. latissimus dorsi, M. posterior deltoid, M. biceps brachii, M. flexor carpi radialis and M. extensor carpi radialis. The push-ups seemed relevant to normalise M. anterior deltoid and M. triceps brachii activity, while isometric maximal voluntary contraction remained the most appropriate method for M. pectoralis major and M. middle deltoid. Thus, original methods are proposed to normalise EMG signal of upper-limb muscles.

  16. Toward an understanding of the emotion-modulated startle eyeblink reflex: the case of anger.

    PubMed

    Peterson, Carly K; Harmon-Jones, Eddie

    2012-11-01

    Three studies investigated the effect of angering pictures on the startle eyeblink response, based on anger's unique identity as an approach-oriented negative affect. In Study 1, eyeblinks to startling noise probes during angering and neutral pictures did not differ, despite angering pictures being rated higher on arousal and anger and more negative in valence. Study 2 replicated Study 1; also, dysphoric participants exhibited potentiated eyeblinks to probes during angering pictures much like those to probes during fear/disgust stimuli. A follow-up study revealed that dysphoric participants rated angering pictures higher in fear. Study 3 again found that eyeblinks to probes during angering and neutral pictures did not differ. Taken together, these results suggest that probes during angering stimuli elicit eyeblinks much like those during neutral stimuli, perhaps due to the competing influences of arousal, valence, and motivation on the startle eyeblink reflex.

  17. Knowledge of electromyography (EMG) in patients undergoing EMG examinations.

    PubMed

    Mondelli, Mauro; Aretini, Alessandro; Greco, Giuseppe

    2014-01-01

    The aim of this study was to evaluate knowledge of electromyography (EMG) in patients undergoing the procedure. In one year, 1,586 consecutive patients (mean age 56 years; 58.8% women) were admitted to two EMG labs to undergo EMG for the first time. The patients found to be "informed" about the how an EMG examination is performed and about the purpose of EMG numbered 448 (28.2%), while those found to be "informed" only about the manner of its execution or only about its purpose numbered 161 (10.2%) and 151 (9.5%), respectively. The remaining 826 (52.1%) patients had either no information, or the information they had was very poor or incorrect (this was particularly true if they had been consulting websites). Being "informed" was associated with level of education (high), type of referring physician (specialist) and with an appropriate referral diagnosis specified in the EMG request. The quality of patient information on EMG was found to be very poor and could be improved. Physicians referring patients for EMG examinations, especially general practitioners, should assume primary responsibility for patient education and counseling in this field.

  18. Effects of meditation practice on spontaneous eyeblink rate.

    PubMed

    Kruis, Ayla; Slagter, Heleen A; Bachhuber, David R W; Davidson, Richard J; Lutz, Antoine

    2016-05-01

    A rapidly growing body of research suggests that meditation can change brain and cognitive functioning. Yet little is known about the neurochemical mechanisms underlying meditation-related changes in cognition. Here, we investigated the effects of meditation on spontaneous eyeblink rates (sEBR), a noninvasive peripheral correlate of striatal dopamine activity. Previous studies have shown a relationship between sEBR and cognitive functions such as mind wandering, cognitive flexibility, and attention-functions that are also affected by meditation. We therefore expected that long-term meditation practice would alter eyeblink activity. To test this, we recorded baseline sEBR and intereyeblink intervals (IEBI) in long-term meditators (LTM) and meditation-naive participants (MNP). We found that LTM not only blinked less frequently, but also showed a different eyeblink pattern than MNP. This pattern had good to high degree of consistency over three time points. Moreover, we examined the effects of an 8-week course of mindfulness-based stress reduction on sEBR and IEBI, compared to an active control group and a waitlist control group. No effect of short-term meditation practice was found. Finally, we investigated whether different types of meditation differentially alter eyeblink activity by measuring sEBR and IEBI after a full day of two kinds of meditation practices in the LTM. No effect of meditation type was found. Taken together, these findings may suggest either that individual difference in dopaminergic neurotransmission is a self-selection factor for meditation practice, or that long-term, but not short-term meditation practice induces stable changes in baseline striatal dopaminergic functioning.

  19. Social determinants of eyeblinks in adult male macaques

    PubMed Central

    Ballesta, Sébastien; Mosher, Clayton P.; Szep, Jeno; Fischl, Kate D.; Gothard, Katalin M.

    2016-01-01

    Videos with rich social and emotional content elicit natural social behaviors in primates. Indeed, while watching videos of conspecifics, monkeys engage in eye contact, gaze follow, and reciprocate facial expressions. We hypothesized that the frequency and timing of eyeblinks also depends on the social signals contained in videos. We monitored the eyeblinks of four male adult macaques while they watched videos of conspecifics displaying facial expressions with direct or averted gaze. The instantaneous blink rate of all four animals decreased during videos. The temporal synchrony of blinking, however, increased in response to segments depicting appeasing or aggressive facial expressions directed at the viewer. Two of the four monkeys, who systematically reciprocated the direct gaze of the stimulus monkeys, also showed eyeblink entrainment, a temporal coordination of blinking between social partners engaged in dyadic interactions. Together, our results suggest that in macaques, as in humans, blinking depends not only on the physiological imperative to protect the eyes and spread a film of tears over the cornea, but also on several socio-emotional factors. PMID:27922101

  20. The role of EMG awareness in EMG biofeedback learning.

    PubMed

    Segreto, J

    1995-06-01

    Underlying most research on biofeedback learning is a theoretical model of the processes involved. The current study tested a prediction from the Awareness Model: High initial EMG awareness should facilitate response control during EMG biofeedback training. Seventy-two undergraduates were assessed for forehead EMG awareness by asking them to produce target responses from 1.0 to 5.0 microV every 15 s for 16 trials. Based on this assessment, two groups (high and low awareness) were trained for 64 trials to produce these target levels with either EMG biofeedback, practice (no feedback), or noncontingent EMG feedback. A transfer task was identical to the initial assessment. During training, the biofeedback group deviated less from target than the practice and noncontingent groups. The biofeedback group was the only group to improve from initial EMG awareness activity. During transfer, only the low awareness biofeedback group remained below initial EMG awareness level. These findings can be interpreted in terms of the Two-Process Model.

  1. Spontaneous Eye-Blinking and Stereotyped Behavior in Older Persons with Mental Retardation

    ERIC Educational Resources Information Center

    Roebel, Amanda M.; MacLean, William E., Jr.

    2007-01-01

    Previous research indicates that abnormal stereotyped movements are associated with central dopamine dysfunction and that eye-blink rate is a noninvasive, in vivo measure of dopamine function. We measured the spontaneous eye-blinking and stereotyped behavior of older adults with severe/profound mental retardation living in a state mental…

  2. Spontaneous Eye-Blinking and Stereotyped Behavior in Older Persons with Mental Retardation

    ERIC Educational Resources Information Center

    Roebel, Amanda M.; MacLean, William E., Jr.

    2007-01-01

    Previous research indicates that abnormal stereotyped movements are associated with central dopamine dysfunction and that eye-blink rate is a noninvasive, in vivo measure of dopamine function. We measured the spontaneous eye-blinking and stereotyped behavior of older adults with severe/profound mental retardation living in a state mental…

  3. Frequent spontaneous eyeblink activity associated with reduced conjunctival surface (trigeminal nerve) tactile sensitivity.

    PubMed

    Doughty, Michael J; Naase, Taher; Button, Norman F

    2009-07-01

    A number of recent studies have reported high spontaneous eyeblink rate (SEBR) values in apparently normal subjects, but the reasons for this are unclear. An assessment was made of SEBR, in 60 educated adult male subjects aged between 22 and 40 years, over a period of 5 min in silence. Half of the subjects were classified as having frequent eyeblink activity. All subjects also had their corneal and conjunctival touch (tactile) sensitivity assessed with a Cochet-Bonnet aesthesiometer immediately after the video recording of SEBR. SEBR ranged from 4.6 to 43.5 (mean 18.6) eyeblinks/min. The SEBR was 26.8 +/- 6.0 eyeblinks/min for those with frequent eyeblink activity as compared to just 10.3 +/- 3.5 eyeblinks/min for those with normal eyeblink activity (p < 0.001). There was no difference in palpebral aperture or exposed ocular surface area between the two groups. The average central corneal sensitivity was only marginally different between the two groups (56.8 +/- 2.8 mm vs 58.5 +/- 2.3 mm) but the conjunctival threshold sensitivity was substantially different (at 23.8 +/- 4.3 mm vs 28.5 +/- 3.5 mm; p < 0.001). SEBR was inversely correlated with the conjunctival sensitivity in those with frequent eyeblink activity (p < 0.001). Our study provides a clue as to the mechanism of inhibition of spontaneous eyeblink activity, namely that a certain level of ocular surface (conjunctival) sensitivity is required to keep SEBR low.

  4. Lumbar iEMG during isotonic exercise: chronic low back pain patients versus controls.

    PubMed

    Robinson, M E; Cassisi, J E; O'Connor, P D; MacMillan, M

    1992-03-01

    Two studies investigated the use of lumbar integrated electromyography (iEMG) during flexion-extension exercises of the lumbar spine. The first study compared the iEMG fatigue slopes of 12 pain-free controls during a standardized isotonic workout with a heavy weight and a light weight. Results indicated that the slopes of the iEMG across flexion-extension repetition was negative in both conditions, with the heavy weight producing significantly steeper fatigue slopes. In the second study, iEMG was compared from 16 chronic low back pain (CLBP) patients and 12 asymptomatic controls during isotonic exercise. Integrated EMG was recorded during 18 lumbar extension-flexion cycles (3 min) at a standard pace. Each subject exercised at a weight equal to 60% of his maximum isometric torque produced at the most extended position. Results indicated significantly less iEMG was produced by the CLBP group during both concentric and eccentric exertion. For both groups, eccentric exertion produced significantly less iEMG than concentric exertion. The groups showed significantly different iEMG fatigue slopes, with the control group showing declining iEMG by repetition, while the CLBP group showed flatter, slightly increasing iEMG. This occurred for both eccentric and concentric comparisons. A muscle deficiency model of CLBP is supported and results suggest the importance of endurance factors in addition to strength in rehabilitation efforts. Results also suggest the possibility of using this methodology for detecting insincere efforts in lumbar spine assessment.

  5. Zebrafish needle EMG: a new tool for high-throughput drug screens

    PubMed Central

    Cho, Sung-Joon; Nam, Tai-Seung; Byun, Donghak; Choi, Seok-Yong; Kim, Myeong-Kyu

    2015-01-01

    Zebrafish models have recently been highlighted as a valuable tool in studying the molecular basis of neuromuscular diseases and developing new pharmacological treatments. Needle electromyography (EMG) is needed not only for validating transgenic zebrafish models with muscular dystrophies (MD), but also for assessing the efficacy of therapeutics. However, performing needle EMG on larval zebrafish has not been feasible due to the lack of proper EMG sensors and systems for such small animals. We introduce a new type of EMG needle electrode to measure intramuscular activities of larval zebrafish, together with a method to hold the animal in position during EMG, without anesthetization. The silicon-based needle electrode was found to be sufficiently strong and sharp to penetrate the skin and muscles of zebrafish larvae, and its shape and performance did not change after multiple insertions. With the use of the proposed needle electrode and measurement system, EMG was successfully performed on zebrafish at 30 days postfertilization (dpf) and at 5 dpf. Burst patterns and spike morphology of the recorded EMG signals were analyzed. The measured single spikes were triphasic with an initial positive deflection, which is typical for motor unit action potentials, with durations of ∼10 ms, whereas the muscle activity was silent during the anesthetized condition. These findings confirmed the capability of this system of detecting EMG signals from very small animals such as 5 dpf zebrafish. The developed EMG sensor and system are expected to become a helpful tool in validating zebrafish MD models and further developing therapeutics. PMID:26180124

  6. Zebrafish needle EMG: a new tool for high-throughput drug screens.

    PubMed

    Cho, Sung-Joon; Nam, Tai-Seung; Byun, Donghak; Choi, Seok-Yong; Kim, Myeong-Kyu; Kim, Sohee

    2015-09-01

    Zebrafish models have recently been highlighted as a valuable tool in studying the molecular basis of neuromuscular diseases and developing new pharmacological treatments. Needle electromyography (EMG) is needed not only for validating transgenic zebrafish models with muscular dystrophies (MD), but also for assessing the efficacy of therapeutics. However, performing needle EMG on larval zebrafish has not been feasible due to the lack of proper EMG sensors and systems for such small animals. We introduce a new type of EMG needle electrode to measure intramuscular activities of larval zebrafish, together with a method to hold the animal in position during EMG, without anesthetization. The silicon-based needle electrode was found to be sufficiently strong and sharp to penetrate the skin and muscles of zebrafish larvae, and its shape and performance did not change after multiple insertions. With the use of the proposed needle electrode and measurement system, EMG was successfully performed on zebrafish at 30 days postfertilization (dpf) and at 5 dpf. Burst patterns and spike morphology of the recorded EMG signals were analyzed. The measured single spikes were triphasic with an initial positive deflection, which is typical for motor unit action potentials, with durations of ∼10 ms, whereas the muscle activity was silent during the anesthetized condition. These findings confirmed the capability of this system of detecting EMG signals from very small animals such as 5 dpf zebrafish. The developed EMG sensor and system are expected to become a helpful tool in validating zebrafish MD models and further developing therapeutics.

  7. Infrared photo-interrupter as an eyeblink detector

    NASA Astrophysics Data System (ADS)

    Utsuki, Narisuke; Takeuchi, Yoshinori

    1990-06-01

    An infrared light-emitting diode (IR-LED) and a phototransistor were paired to make an easy-to-use equipment to record eyeblinking. Since reflecting power is different between the eyelid and the cornea, the amount of reflected light cab indicate whether the eyelid is closed or opened. The IR-LED was driven by a 1,200 Hz electric pulse so that the detected infrared light could be amplified as an alternative current, filtered, and recorded on a regular cassette tape recorder. The devices were attached to eyeglasses. The estimated infrared radiation level was 0.5 mW/sq cm on the surface of the cornea. The safety limit of the IR exposure is discussed.

  8. Electrotactile EMG feedback improves the control of prosthesis grasping force

    NASA Astrophysics Data System (ADS)

    Schweisfurth, Meike A.; Markovic, Marko; Dosen, Strahinja; Teich, Florian; Graimann, Bernhard; Farina, Dario

    2016-10-01

    predictive control, as the subjects used the feedback to adjust the desired force even before the prosthesis contacted the object. In conclusion, the online emgFB was superior to the classic forceFB in realistic conditions that included electrotactile stimulation, limited feedback resolution (8 levels), cognitive processing delay, and time constraints (fast grasping).

  9. Measurement of EMG activity with textile electrodes embedded into clothing.

    PubMed

    Finni, T; Hu, M; Kettunen, P; Vilavuo, T; Cheng, S

    2007-11-01

    Novel textile electrodes that can be embedded into sports clothing to measure averaged rectified electromyography (EMG) have been developed for easy use in field tests and in clinical settings. The purpose of this study was to evaluate the validity, reliability and feasibility of this new product to measure averaged rectified EMG. The validity was tested by comparing the signals from bipolar textile electrodes (42 cm(2)) and traditional bipolar surface electrodes (1.32 cm(2)) during bilateral isometric knee extension exercise with two electrode locations (A: both electrodes located in the same place, B: traditional electrodes placed on the individual muscles according to SENIAM, n=10 persons for each). Within-session repeatability (the coefficient of variation CV%, n=10) was calculated from five repetitions of 60% maximum voluntary contraction (MVC). The day-to-day repeatability (n=8) was assessed by measuring three different isometric force levels on five consecutive days. The feasibility of the textile electrodes in field conditions was assessed during a maximal treadmill test (n=28). Bland-Altman plots showed a good agreement within 2SD between the textile and traditional electrodes, demonstrating that the textile electrodes provide similar information on the EMG signal amplitude to the traditional electrodes. The within-session CV ranged from 13% to 21% in both the textile and traditional electrodes. The day-to-day CV was smaller, ranging from 4% to 11% for the textile electrodes. A similar relationship (r(2)=0.5) was found between muscle strength and the EMG of traditional and textile electrodes. The feasibility study showed that the textile electrode technique can potentially make EMG measurements very easy in field conditions. This study indicates that textile electrodes embedded into shorts is a valid and feasible method for assessing the average rectified value of EMG.

  10. Characteristics of EMG frequency bands in temporomandibullar disorders patients.

    PubMed

    Politti, Fabiano; Casellato, Claudia; Kalytczak, Marcelo Martins; Garcia, Marilia Barbosa Santos; Biasotto-Gonzalez, Daniela Aparecida

    2016-12-01

    The aim of the present study was to determine whether any specific frequency bands of surface electromyographic (sEMG) signals are more susceptible to alterations in patients with temporomandibular disorders (TMD), when compared with healthy subjects. Twenty-seven healthy adults (19 women and eight men; mean age: 23±6.68years) and 27 TMD patients (20 women and seven men; mean age: 24±5.89years) voluntarily participated in the experiment. sEMG data were recorded from the right and left masseter muscles (RM and LM) and the right and left anterior temporalis muscles (RT and LT) as the participants performed tests of chewing (CHW) and maximal clenching effort (MCE). Frequency domain analysis of the sEMG signal was used to analyze differences between TMD patients and healthy subjects in relation to the Power Spectral Density Function (PSDF). The analysis focused on the median frequency (MDF) of the sEMG signal and PSDF frequency bands after the EMG spectrum was divided into twenty-five frequency band of 20Hz each. The Mann-Whitney test was used to compare MDF between TMD patients and healthy subjects and the frequency bands were analyzed using three-way ANOVA with three factors: frequency band, muscle and group. The results of the analysis confirmed that the median frequency values in TMD patients were significantly higher (p<0.05) than those recorded for healthy subjects in the two experimental conditions (MCE and CHW), for all of the muscles assessed (RM, LM, RT and LT). In addition, frequency content between 20 and 100Hz of the normalized PSDF range was significantly lower (p<0.05) in TMD patients than in healthy. This study contributes to quantitatively identify TMD dysfunctions, by non-invasive sEMGs; this assessment is clinically important and still lacking nowadays. Copyright © 2016 Elsevier Ltd. All rights reserved.

  11. Power spectrum of the rectified EMG: when and why is rectification beneficial for identifying neural connectivity?

    PubMed

    Negro, Francesco; Keenan, Kevin; Farina, Dario

    2015-06-01

    The identification of common oscillatory inputs to motor neurons in the electromyographic (EMG) signal power spectrum is often preceded by EMG rectification for enhancing the low-frequency oscillatory components. However, rectification is a nonlinear operator and its influence on the EMG signal spectrum is not fully understood. In this study, we aim at determining when EMG rectification is beneficial in the study of oscillatory inputs to motor neurons. We provide a full mathematical description of the power spectrum of the rectified EMG signal and the influence of the average shape of the motor unit action potentials on it. We also provide a validation of these theoretical results with both simulated and experimental EMG signals. Simulations using an advanced computational model and experimental results demonstrated the accuracy of the theoretical derivations on the effect of rectification on the EMG spectrum. These derivations proved that rectification is beneficial when assessing the strength of low-frequency (delta and alpha bands) common synaptic inputs to the motor neurons, when the duration of the action potentials is short, and when the level of cancellation is relatively low. On the other hand, rectification may distort the estimation of common synaptic inputs when studying higher frequencies (beta and gamma), in a way dependent on the duration of the action potentials, and may introduce peaks in the coherence function that do not correspond to physiological shared inputs. This study clarifies the conditions when rectifying the surface EMG is appropriate for studying neural connectivity.

  12. Power spectrum of the rectified EMG: when and why is rectification beneficial for identifying neural connectivity?

    NASA Astrophysics Data System (ADS)

    Negro, Francesco; Keenan, Kevin; Farina, Dario

    2015-06-01

    Objective. The identification of common oscillatory inputs to motor neurons in the electromyographic (EMG) signal power spectrum is often preceded by EMG rectification for enhancing the low-frequency oscillatory components. However, rectification is a nonlinear operator and its influence on the EMG signal spectrum is not fully understood. In this study, we aim at determining when EMG rectification is beneficial in the study of oscillatory inputs to motor neurons. Approach. We provide a full mathematical description of the power spectrum of the rectified EMG signal and the influence of the average shape of the motor unit action potentials on it. We also provide a validation of these theoretical results with both simulated and experimental EMG signals. Main results. Simulations using an advanced computational model and experimental results demonstrated the accuracy of the theoretical derivations on the effect of rectification on the EMG spectrum. These derivations proved that rectification is beneficial when assessing the strength of low-frequency (delta and alpha bands) common synaptic inputs to the motor neurons, when the duration of the action potentials is short, and when the level of cancellation is relatively low. On the other hand, rectification may distort the estimation of common synaptic inputs when studying higher frequencies (beta and gamma), in a way dependent on the duration of the action potentials, and may introduce peaks in the coherence function that do not correspond to physiological shared inputs. Significance. This study clarifies the conditions when rectifying the surface EMG is appropriate for studying neural connectivity.

  13. Analysis of the sEMG/force relationship using HD-sEMG technique and data fusion: A simulation study.

    PubMed

    Al Harrach, Mariam; Carriou, Vincent; Boudaoud, Sofiane; Laforet, Jeremy; Marin, Frederic

    2017-04-01

    The relationship between the surface Electromyogram (sEMG) signal and the force of an individual muscle is still ambiguous due to the complexity of experimental evaluation. However, understanding this relationship should be useful for the assessment of neuromuscular system in healthy and pathological contexts. In this study, we present a global investigation of the factors governing the shape of this relationship. Accordingly, we conducted a focused sensitivity analysis of the sEMG/force relationship form with respect to neural, functional and physiological parameters variation. For this purpose, we used a fast generation cylindrical model for the simulation of an 8×8 High Density-sEMG (HD-sEMG) grid and a twitch based force model for the muscle force generation. The HD-sEMG signals as well as the corresponding force signals were simulated in isometric non-fatiguing conditions and were based on the Biceps Brachii (BB) muscle properties. A total of 10 isometric constant contractions of 5s were simulated for each configuration of parameters. The Root Mean Squared (RMS) value was computed in order to quantify the sEMG amplitude. Then, an image segmentation method was used for data fusion of the 8×8 RMS maps. In addition, a comparative study between recent modeling propositions and the model proposed in this study is presented. The evaluation was made by computing the Normalized Root Mean Squared Error (NRMSE) of their fitting to the simulated relationship functions. Our results indicated that the relationship between the RMS (mV) and muscle force (N) can be modeled using a 3rd degree polynomial equation. Moreover, it appears that the obtained coefficients are patient-specific and dependent on physiological, anatomical and neural parameters. Copyright © 2017 Elsevier Ltd. All rights reserved.

  14. Evaluation of jaw and neck muscle activities while chewing using EMG-EMG transfer function and EMG-EMG coherence function analyses in healthy subjects.

    PubMed

    Ishii, Tomohiro; Narita, Noriyuki; Endo, Hiroshi

    2016-06-01

    This study aims to quantitatively clarify the physiological features in rhythmically coordinated jaw and neck muscle EMG activities while chewing gum using EMG-EMG transfer function and EMG-EMG coherence function analyses in 20 healthy subjects. The chewing side masseter muscle EMG signal was used as the reference signal, while the other jaw (non-chewing side masseter muscle, bilateral anterior temporal muscles, and bilateral anterior digastric muscles) and neck muscle (bilateral sternocleidomastoid muscles) EMG signals were used as the examined signals in EMG-EMG transfer function and EMG-EMG coherence function analyses. Chewing-related jaw and neck muscle activities were aggregated in the first peak of the power spectrum in rhythmic chewing. The gain in the peak frequency represented the power relationships between jaw and neck muscle activities during rhythmic chewing. The phase in the peak frequency represented the temporal relationships between the jaw and neck muscle activities, while the non-chewing side neck muscle presented a broad range of distributions across jaw closing and opening phases. Coherence in the peak frequency represented the synergistic features in bilateral jaw closing muscles and chewing side neck muscle activities. The coherence and phase in non-chewing side neck muscle activities exhibited a significant negative correlation. From above, the bilateral coordination between the jaw and neck muscle activities is estimated while chewing when the non-chewing side neck muscle is synchronously activated with the jaw closing muscles, while the unilateral coordination is estimated when the non-chewing side neck muscle is irregularly activated in the jaw opening phase. Thus, the occurrence of bilateral or unilateral coordinated features in the jaw and neck muscle activities may correspond to the phase characteristics in the non-chewing side neck muscle activities during rhythmical chewing. Considering these novel findings in healthy subjects, EMG-EMG

  15. Experimentally induced stress validated by EMG activity.

    PubMed

    Luijcks, Rosan; Hermens, Hermie J; Bodar, Lonneke; Vossen, Catherine J; Van Os, Jim; Lousberg, Richel

    2014-01-01

    Experience of stress may lead to increased electromyography (EMG) activity in specific muscles compared to a non-stressful situation. The main aim of this study was to develop and validate a stress-EMG paradigm in which a single uncontrollable and unpredictable nociceptive stimulus was presented. EMG activity of the trapezius muscles was the response of interest. In addition to linear time effects, non-linear EMG time courses were also examined. Taking into account the hierarchical structure of the dataset, a multilevel random regression model was applied. The stress paradigm, executed in N = 70 subjects, consisted of a 3-minute baseline measurement, a 3-minute pre-stimulus stress period and a 2-minute post-stimulus phase. Subjects were unaware of the precise moment of stimulus delivery and its intensity level. EMG activity during the entire experiment was conform a priori expectations: the pre-stimulus phase showed a significantly higher mean EMG activity level compared to the other two phases, and an immediate EMG response to the stimulus was demonstrated. In addition, the analyses revealed significant non-linear EMG time courses in all three phases. Linear and quadratic EMG time courses were significantly modified by subjective anticipatory stress level, measured just before the start of the stress task. Linking subjective anticipatory stress to EMG stress reactivity revealed that subjects with a high anticipatory stress level responded with more EMG activity during the pre-stimulus stress phase, whereas subjects with a low stress level showed an inverse effect. Results suggest that the stress paradigm presented here is a valid test to quantify individual differences in stress susceptibility. Further studies with this paradigm are required to demonstrate its potential use in mechanistic clinical studies.

  16. EMG Processing Based Measures of Fatigue Assessment during Manual Lifting

    PubMed Central

    Marhaban, M. H.; Abdullah, A. R.

    2017-01-01

    Manual lifting is one of the common practices used in the industries to transport or move objects to a desired place. Nowadays, even though mechanized equipment is widely available, manual lifting is still considered as an essential way to perform material handling task. Improper lifting strategies may contribute to musculoskeletal disorders (MSDs), where overexertion contributes as the highest factor. To overcome this problem, electromyography (EMG) signal is used to monitor the workers' muscle condition and to find maximum lifting load, lifting height and number of repetitions that the workers are able to handle before experiencing fatigue to avoid overexertion. Past researchers have introduced several EMG processing techniques and different EMG features that represent fatigue indices in time, frequency, and time-frequency domain. The impact of EMG processing based measures in fatigue assessment during manual lifting are reviewed in this paper. It is believed that this paper will greatly benefit researchers who need a bird's eye view of the biosignal processing which are currently available, thus determining the best possible techniques for lifting applications. PMID:28303251

  17. EMG Processing Based Measures of Fatigue Assessment during Manual Lifting.

    PubMed

    Shair, E F; Ahmad, S A; Marhaban, M H; Mohd Tamrin, S B; Abdullah, A R

    2017-01-01

    Manual lifting is one of the common practices used in the industries to transport or move objects to a desired place. Nowadays, even though mechanized equipment is widely available, manual lifting is still considered as an essential way to perform material handling task. Improper lifting strategies may contribute to musculoskeletal disorders (MSDs), where overexertion contributes as the highest factor. To overcome this problem, electromyography (EMG) signal is used to monitor the workers' muscle condition and to find maximum lifting load, lifting height and number of repetitions that the workers are able to handle before experiencing fatigue to avoid overexertion. Past researchers have introduced several EMG processing techniques and different EMG features that represent fatigue indices in time, frequency, and time-frequency domain. The impact of EMG processing based measures in fatigue assessment during manual lifting are reviewed in this paper. It is believed that this paper will greatly benefit researchers who need a bird's eye view of the biosignal processing which are currently available, thus determining the best possible techniques for lifting applications.

  18. Effects of load on good morning kinematics and EMG activity.

    PubMed

    Vigotsky, Andrew David; Harper, Erin Nicole; Ryan, David Russell; Contreras, Bret

    2015-01-01

    Many strength and conditioning coaches utilize the good morning (GM) to strengthen the hamstrings and spinal erectors. However, little research exists on its electromyography (EMG) activity and kinematics, and how these variables change as a function of load. The purpose of this investigation was to examine how estimated hamstring length, integrated EMG (IEMG) activity of the hamstrings and spinal erectors, and kinematics of the lumbar spine, hip, knee, and ankle are affected by changes in load. Fifteen trained male participants (age = 24.6 ± 5.3 years; body mass = 84.7 ± 11.3 kg; height = 180.9 ± 6.8 cm) were recruited for this study. Participants performed five sets of the GM, utilizing 50, 60, 70, 80, and 90% of one-repetition maximum (1RM) in a randomized fashion. IEMG activity of hamstrings and spinal erectors tended to increase with load. Knee flexion increased with load on all trials. Estimated hamstring length decreased with load. However, lumbar flexion, hip flexion, and plantar flexion experienced no remarkable changes between trials. These data provide insight as to how changing the load of the GM affects EMG activity, kinematic variables, and estimated hamstring length. Implications for hamstring injury prevention are discussed. More research is needed for further insight as to how load affects EMG activity and kinematics of other exercises.

  19. Effects of load on good morning kinematics and EMG activity

    PubMed Central

    Harper, Erin Nicole; Ryan, David Russell; Contreras, Bret

    2015-01-01

    Many strength and conditioning coaches utilize the good morning (GM) to strengthen the hamstrings and spinal erectors. However, little research exists on its electromyography (EMG) activity and kinematics, and how these variables change as a function of load. The purpose of this investigation was to examine how estimated hamstring length, integrated EMG (IEMG) activity of the hamstrings and spinal erectors, and kinematics of the lumbar spine, hip, knee, and ankle are affected by changes in load. Fifteen trained male participants (age = 24.6 ± 5.3 years; body mass = 84.7 ± 11.3 kg; height = 180.9 ± 6.8 cm) were recruited for this study. Participants performed five sets of the GM, utilizing 50, 60, 70, 80, and 90% of one-repetition maximum (1RM) in a randomized fashion. IEMG activity of hamstrings and spinal erectors tended to increase with load. Knee flexion increased with load on all trials. Estimated hamstring length decreased with load. However, lumbar flexion, hip flexion, and plantar flexion experienced no remarkable changes between trials. These data provide insight as to how changing the load of the GM affects EMG activity, kinematic variables, and estimated hamstring length. Implications for hamstring injury prevention are discussed. More research is needed for further insight as to how load affects EMG activity and kinematics of other exercises. PMID:25653899

  20. EMG patterns during assisted walking in the exoskeleton.

    PubMed

    Sylos-Labini, Francesca; La Scaleia, Valentina; d'Avella, Andrea; Pisotta, Iolanda; Tamburella, Federica; Scivoletto, Giorgio; Molinari, Marco; Wang, Shiqian; Wang, Letian; van Asseldonk, Edwin; van der Kooij, Herman; Hoellinger, Thomas; Cheron, Guy; Thorsteinsson, Freygardur; Ilzkovitz, Michel; Gancet, Jeremi; Hauffe, Ralf; Zanov, Frank; Lacquaniti, Francesco; Ivanenko, Yuri P

    2014-01-01

    Neuroprosthetic technology and robotic exoskeletons are being developed to facilitate stepping, reduce muscle efforts, and promote motor recovery. Nevertheless, the guidance forces of an exoskeleton may influence the sensory inputs, sensorimotor interactions and resulting muscle activity patterns during stepping. The aim of this study was to report the muscle activation patterns in a sample of intact and injured subjects while walking with a robotic exoskeleton and, in particular, to quantify the level of muscle activity during assisted gait. We recorded electromyographic (EMG) activity of different leg and arm muscles during overground walking in an exoskeleton in six healthy individuals and four spinal cord injury (SCI) participants. In SCI patients, EMG activity of the upper limb muscles was augmented while activation of leg muscles was typically small. Contrary to our expectations, however, in neurologically intact subjects, EMG activity of leg muscles was similar or even larger during exoskeleton-assisted walking compared to normal overground walking. In addition, significant variations in the EMG waveforms were found across different walking conditions. The most variable pattern was observed in the hamstring muscles. Overall, the results are consistent with a non-linear reorganization of the locomotor output when using the robotic stepping devices. The findings may contribute to our understanding of human-machine interactions and adaptation of locomotor activity patterns.

  1. EMG patterns during assisted walking in the exoskeleton

    PubMed Central

    Sylos-Labini, Francesca; La Scaleia, Valentina; d'Avella, Andrea; Pisotta, Iolanda; Tamburella, Federica; Scivoletto, Giorgio; Molinari, Marco; Wang, Shiqian; Wang, Letian; van Asseldonk, Edwin; van der Kooij, Herman; Hoellinger, Thomas; Cheron, Guy; Thorsteinsson, Freygardur; Ilzkovitz, Michel; Gancet, Jeremi; Hauffe, Ralf; Zanov, Frank; Lacquaniti, Francesco; Ivanenko, Yuri P.

    2014-01-01

    Neuroprosthetic technology and robotic exoskeletons are being developed to facilitate stepping, reduce muscle efforts, and promote motor recovery. Nevertheless, the guidance forces of an exoskeleton may influence the sensory inputs, sensorimotor interactions and resulting muscle activity patterns during stepping. The aim of this study was to report the muscle activation patterns in a sample of intact and injured subjects while walking with a robotic exoskeleton and, in particular, to quantify the level of muscle activity during assisted gait. We recorded electromyographic (EMG) activity of different leg and arm muscles during overground walking in an exoskeleton in six healthy individuals and four spinal cord injury (SCI) participants. In SCI patients, EMG activity of the upper limb muscles was augmented while activation of leg muscles was typically small. Contrary to our expectations, however, in neurologically intact subjects, EMG activity of leg muscles was similar or even larger during exoskeleton-assisted walking compared to normal overground walking. In addition, significant variations in the EMG waveforms were found across different walking conditions. The most variable pattern was observed in the hamstring muscles. Overall, the results are consistent with a non-linear reorganization of the locomotor output when using the robotic stepping devices. The findings may contribute to our understanding of human-machine interactions and adaptation of locomotor activity patterns. PMID:24982628

  2. Eliminating ultrasonic interference from respiratory muscle EMG.

    PubMed

    Platt, R S; Kieser, T M; Easton, P A

    1998-05-01

    Fine wire recordings of the respiratory muscle electromyogram are often employed to represent muscle activity, and recently ultrasound-sonomicrometry has become a common method of measuring length of respiratory muscles in both acute and chronic preparations. Although recording both EMG and sonomicrometry simultaneously has become standard practice, there has not been any consideration of the potential confounding influence of ultrasound noise upon the recorded EMG spectrum. Activation of the sonomicrometry-ultrasound tranducer introduces a high frequency, high amplitude voltage pulse plus harmonics, which can contaminate the EMG spectrum directly, as well as through aliasing when EMG is sampled directly digitally. We describe the use of a new, combined, wing stabilized sonomicrometry- and EMG measurement transducer to characterize exactly the influence of ultrasound upon the crural diaphragm EMG spectrum, and the development of digital filtering techniques which effectively eliminate the ultrasound interference. Two alternative methods of avoiding ultrasound-EMG interference are also considered. The isolation and elimination of ultrasound-sonomicrometry signal interference may be important in studies where EMG and length are measured together.

  3. Emotionally excited eyeblink-rate variability predicts an experience of transportation into the narrative world

    PubMed Central

    Nomura, Ryota; Hino, Kojun; Shimazu, Makoto; Liang, Yingzong; Okada, Takeshi

    2015-01-01

    Collective spectator communications such as oral presentations, movies, and storytelling performances are ubiquitous in human culture. This study investigated the effects of past viewing experiences and differences in expressive performance on an audience’s transportive experience into a created world of a storytelling performance. In the experiment, 60 participants (mean age = 34.12 years, SD = 13.18 years, range 18–63 years) were assigned to watch one of two videotaped performances that were played (1) in an orthodox way for frequent viewers and (2) in a modified way aimed at easier comprehension for first-time viewers. Eyeblink synchronization among participants was quantified by employing distance-based measurements of spike trains, Dspike and Dinterval (Victor and Purpura, 1997). The results indicated that even non-familiar participants’ eyeblinks were synchronized as the story progressed and that the effect of the viewing experience on transportation was weak. Rather, the results of a multiple regression analysis demonstrated that the degrees of transportation could be predicted by a retrospectively reported humor experience and higher real-time variability (i.e., logarithmic transformed SD) of inter blink intervals during a performance viewing. The results are discussed from the viewpoint in which the extent of eyeblink synchronization and eyeblink-rate variability acts as an index of the inner experience of audience members. PMID:26029123

  4. Affective Modulation of the Startle Eyeblink and Postauricular Reflexes in Autism Spectrum Disorder

    ERIC Educational Resources Information Center

    Dichter, Gabriel S.; Benning, Stephen D.; Holtzclaw, Tia N.; Bodfish, James W.

    2010-01-01

    Eyeblink and postauricular reflexes to standardized affective images were examined in individuals without (n = 37) and with (n = 20) autism spectrum disorders (ASDs). Affective reflex modulation in control participants replicated previous findings. The ASD group, however, showed anomalous reflex modulation patterns, despite similar self-report…

  5. Affective Modulation of the Startle Eyeblink and Postauricular Reflexes in Autism Spectrum Disorder

    ERIC Educational Resources Information Center

    Dichter, Gabriel S.; Benning, Stephen D.; Holtzclaw, Tia N.; Bodfish, James W.

    2010-01-01

    Eyeblink and postauricular reflexes to standardized affective images were examined in individuals without (n = 37) and with (n = 20) autism spectrum disorders (ASDs). Affective reflex modulation in control participants replicated previous findings. The ASD group, however, showed anomalous reflex modulation patterns, despite similar self-report…

  6. Reflex Augmentation of a Tap-Elicited Eyeblink: The Effects of Tone Frequency and Tap Intensity.

    ERIC Educational Resources Information Center

    Cohen, Michelle E.; And Others

    1986-01-01

    Describes two experiments that examined whether the amplitude of the human eyeblink by a mild tap between the eyebrows can be increased if a brief tone is presented simultaneously with the tap and how these effects change from newborn infants to adults. (HOD)

  7. Reflex Augmentation of a Tap-Elicited Eyeblink: The Effects of Tone Frequency and Tap Intensity.

    ERIC Educational Resources Information Center

    Cohen, Michelle E.; And Others

    1986-01-01

    Describes two experiments that examined whether the amplitude of the human eyeblink by a mild tap between the eyebrows can be increased if a brief tone is presented simultaneously with the tap and how these effects change from newborn infants to adults. (HOD)

  8. Clinical relevance of surface EMG of the masticatory muscles. (Part 1): Resting activity, maximal and submaximal voluntary contraction, symmetry of EMG activity.

    PubMed

    Hugger, S; Schindler, H J; Kordass, B; Hugger, A

    2012-01-01

    Based on a comprehensive computerized literature search supplemented by a specific manual search of the literature, the present review article focuses on concrete aspects of the application of surface electromyography (EMG) for evaluation of the masticatory muscles in general and of the masseter and anterior temporal muscles in particular, and presents the current base of knowledge on the clinical relevance of surface EMG in dental applications. In the first stage of the review, publications from the year 2000 or later reporting the results of controlled clinical trials (randomized as far as available) of patients with craniomandibular or temporomandibular disorders (TMD) were analyzed. Data from the selected publications were systematically compiled and divided into subject areas as follows: Resting activity, maximal and sub-maximal voluntary contraction, symmetry of EMG activity, and fatigue effects; EMG activity during mastication, factors (including pain) that affect EMG activity, and the impact of adjusting static and dynamic occlusal relationships; Effects of occlusal splints and other occlusal treatments. Surface electromyography is in principle a suitable tool for neuromuscular function analysis in the field of dentistry. If used according to the specific recommendations and in conjunction with a thorough and conscientious clinical history and physical examination, surface EMG measurements can provide objective, documentable, valid, and reproducible data on the functional condition of the masticatory muscles of an individual patient.

  9. Epoch length to accurately estimate the amplitude of interference EMG is likely the result of unavoidable amplitude cancellation

    PubMed Central

    Keenan, Kevin G.; Valero-Cuevas, Francisco J.

    2008-01-01

    Researchers and clinicians routinely rely on interference electromyograms (EMGs) to estimate muscle forces and command signals in the neuromuscular system (e.g., amplitude, timing, and frequency content). The amplitude cancellation intrinsic to interference EMG, however, raises important questions about how to optimize these estimates. For example, what should the length of the epoch (time window) be to average an EMG signal to reliably estimate muscle forces and command signals? Shorter epochs are most practical, and significant reductions in epoch have been reported with high-pass filtering and whitening. Given that this processing attenuates power at frequencies of interest (< 250 Hz), however, it is unclear how it improves the extraction of physiologically-relevant information. We examined the influence of amplitude cancellation and high-pass filtering on the epoch necessary to accurately estimate the “true” average EMG amplitude calculated from a 28 s EMG trace (EMGref) during simulated constant isometric conditions. Monte Carlo iterations of a motor-unit model simulating 28 s of surface EMG produced 245 simulations under 2 conditions: with and without amplitude cancellation. For each simulation, we calculated the epoch necessary to generate average full-wave rectified EMG amplitudes that settled within 5% of EMGref. For the no-cancellation EMG, the necessary epochs were short (e.g., < 100 ms). For the more realistic interference EMG (i.e., cancellation condition), epochs shortened dramatically after using high-pass filter cutoffs above 250 Hz, producing epochs short enough to be practical (i.e., < 500 ms). We conclude that the need to use long epochs to accurately estimate EMG amplitude is likely the result of unavoidable amplitude cancellation, which helps to clarify why high-pass filtering (> 250 Hz) improves EMG estimates. PMID:19081815

  10. Gesture recognition by instantaneous surface EMG images

    PubMed Central

    Geng, Weidong; Du, Yu; Jin, Wenguang; Wei, Wentao; Hu, Yu; Li, Jiajun

    2016-01-01

    Gesture recognition in non-intrusive muscle-computer interfaces is usually based on windowed descriptive and discriminatory surface electromyography (sEMG) features because the recorded amplitude of a myoelectric signal may rapidly fluctuate between voltages above and below zero. Here, we present that the patterns inside the instantaneous values of high-density sEMG enables gesture recognition to be performed merely with sEMG signals at a specific instant. We introduce the concept of an sEMG image spatially composed from high-density sEMG and verify our findings from a computational perspective with experiments on gesture recognition based on sEMG images with a classification scheme of a deep convolutional network. Without any windowed features, the resultant recognition accuracy of an 8-gesture within-subject test reached 89.3% on a single frame of sEMG image and reached 99.0% using simple majority voting over 40 frames with a 1,000 Hz sampling rate. Experiments on the recognition of 52 gestures of NinaPro database and 27 gestures of CSL-HDEMG database also validated that our approach outperforms state-of-the-arts methods. Our findings are a starting point for the development of more fluid and natural muscle-computer interfaces with very little observational latency. For example, active prostheses and exoskeletons based on high-density electrodes could be controlled with instantaneous responses. PMID:27845347

  11. Gesture recognition by instantaneous surface EMG images.

    PubMed

    Geng, Weidong; Du, Yu; Jin, Wenguang; Wei, Wentao; Hu, Yu; Li, Jiajun

    2016-11-15

    Gesture recognition in non-intrusive muscle-computer interfaces is usually based on windowed descriptive and discriminatory surface electromyography (sEMG) features because the recorded amplitude of a myoelectric signal may rapidly fluctuate between voltages above and below zero. Here, we present that the patterns inside the instantaneous values of high-density sEMG enables gesture recognition to be performed merely with sEMG signals at a specific instant. We introduce the concept of an sEMG image spatially composed from high-density sEMG and verify our findings from a computational perspective with experiments on gesture recognition based on sEMG images with a classification scheme of a deep convolutional network. Without any windowed features, the resultant recognition accuracy of an 8-gesture within-subject test reached 89.3% on a single frame of sEMG image and reached 99.0% using simple majority voting over 40 frames with a 1,000 Hz sampling rate. Experiments on the recognition of 52 gestures of NinaPro database and 27 gestures of CSL-HDEMG database also validated that our approach outperforms state-of-the-arts methods. Our findings are a starting point for the development of more fluid and natural muscle-computer interfaces with very little observational latency. For example, active prostheses and exoskeletons based on high-density electrodes could be controlled with instantaneous responses.

  12. Motor imagery modulation of postural sway is accompanied by changes in the EMG-COP association.

    PubMed

    Lemos, Thiago; Rodrigues, Erika C; Vargas, Claudia D

    2014-08-08

    Motor imagery (MI) performed in an upright stance promotes increases in postural sway without changes in usual amplitude measures of calf muscle EMG. However, postural muscle activity can also be determined from the temporal association between EMG and center of pressure (COP) displacements. In this study we investigated whether the MI modulation of postural sway is accompanied by changes in EMG-COP association. Surface EMG from the lateral gastrocnemius (LG) muscle and COP coordinates were collected from 12 subjects while they imagined themselves performing a rising on tiptoes movement via kinesthetic or visual imagery. As a control condition subjects were requested to imagine singing a song. The standard deviation of the forward-backward COP sway and the coefficient of variation of the EMG were calculated and compared across tasks. The degree of association between COP sways and LG activity was evaluated through a cross-correlation function. Kinesthetic imagery promoted a larger COP displacement than both visual and control imagery (p<0.02). No difference in EMG amplitude was observed across imagery tasks (p=0.08). Crucially, we found a stronger EMG-COP association during kinesthetic imagery compared to control imagery (p=0.02), whereas the EMG-COP association in visual imagery was not different from that observed during kinesthetic or control imagery (p>0.19). In conclusion, kinesthetic imagery resulted in a higher EMG-COP temporal association. Subliminal fringe mechanisms may account for the imagery effects on muscle activity and postural sway during upright stance. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  13. Eyeblink rate watching classical Hollywood and post-classical MTV editing styles, in media and non-media professionals.

    PubMed

    Andreu-Sánchez, Celia; Martín-Pascual, Miguel Ángel; Gruart, Agnès; Delgado-García, José María

    2017-02-21

    While movie edition creates a discontinuity in audio-visual works for narrative and economy-of-storytelling reasons, eyeblink creates a discontinuity in visual perception for protective and cognitive reasons. We were interested in analyzing eyeblink rate linked to cinematographic edition styles. We created three video stimuli with different editing styles and analyzed spontaneous blink rate in participants (N = 40). We were also interested in looking for different perceptive patterns in blink rate related to media professionalization. For that, of our participants, half (n = 20) were media professionals, and the other half were not. According to our results, MTV editing style inhibits eyeblinks more than Hollywood style and one-shot style. More interestingly, we obtained differences in visual perception related to media professionalization: we found that media professionals inhibit eyeblink rate substantially compared with non-media professionals, in any style of audio-visual edition.

  14. Eyeblink rate watching classical Hollywood and post-classical MTV editing styles, in media and non-media professionals

    PubMed Central

    Andreu-Sánchez, Celia; Martín-Pascual, Miguel Ángel; Gruart, Agnès; Delgado-García, José María

    2017-01-01

    While movie edition creates a discontinuity in audio-visual works for narrative and economy-of-storytelling reasons, eyeblink creates a discontinuity in visual perception for protective and cognitive reasons. We were interested in analyzing eyeblink rate linked to cinematographic edition styles. We created three video stimuli with different editing styles and analyzed spontaneous blink rate in participants (N = 40). We were also interested in looking for different perceptive patterns in blink rate related to media professionalization. For that, of our participants, half (n = 20) were media professionals, and the other half were not. According to our results, MTV editing style inhibits eyeblinks more than Hollywood style and one-shot style. More interestingly, we obtained differences in visual perception related to media professionalization: we found that media professionals inhibit eyeblink rate substantially compared with non-media professionals, in any style of audio-visual edition. PMID:28220882

  15. Specialized Nerve Tests: EMG, NCV and SSEP

    MedlinePlus

    ... Nerve Tests: EMG, NCV and SEEP Alternative Medicine Acupuncture Herbal Supplements Surgical Options Anterior Cervical Fusion Artifical ... are very thin, about the size of an acupuncture needle. The doctor will move the needle up ...

  16. [The effect of EMG level by EMG biofeedback with progressive muscle relaxation training on tension headache].

    PubMed

    Ro, U J; Kim, N C; Kim, H S

    1990-08-01

    The purpose of this study is to assess if EMG biofeedback training with progressive muscle relaxation training is effective in reducing the EMG level in patients with tension headaches. This study which lasted from 23 October to 30 December 1989, was conducted on 10 females who were diagnosed as patients with tension headaches and selected from among volunteers at C. University in Seoul. The process of the study was as follows: First, before the treatment, the baseline was measured for two weeks and the level of EMG was measured five times in five minutes. And then EMG biofeedback training was used for six weeks, 12 sessions in all, and progressive muscle relaxation was done at home by audio tape over eight weeks. Each session was composed of a 5-minute baseline, two 5-minute EMG biofeedback training periods and a 5-minute self-control stage. Each stage was followed by a five minute rest period. So each session took a total of 40 minutes. The EMG level was measured by EMG biofeedback (Autogenic-Cyborg: M 130 EMG module). The results were as follows: 1. The average age of the subjects was 44.1 years and the average history of headache was 10.6 years (range: 6 months-20 years). 2. The level of EMG was lowest between the third and the fourth week of the training except in Cases I and IV. 3. The patients began to show a nonconciliatory attitude at the first session of the fifth week of the training.

  17. Gesture Based Control and EMG Decomposition

    NASA Technical Reports Server (NTRS)

    Wheeler, Kevin R.; Chang, Mindy H.; Knuth, Kevin H.

    2005-01-01

    This paper presents two probabilistic developments for use with Electromyograms (EMG). First described is a new-electric interface for virtual device control based on gesture recognition. The second development is a Bayesian method for decomposing EMG into individual motor unit action potentials. This more complex technique will then allow for higher resolution in separating muscle groups for gesture recognition. All examples presented rely upon sampling EMG data from a subject's forearm. The gesture based recognition uses pattern recognition software that has been trained to identify gestures from among a given set of gestures. The pattern recognition software consists of hidden Markov models which are used to recognize the gestures as they are being performed in real-time from moving averages of EMG. Two experiments were conducted to examine the feasibility of this interface technology. The first replicated a virtual joystick interface, and the second replicated a keyboard. Moving averages of EMG do not provide easy distinction between fine muscle groups. To better distinguish between different fine motor skill muscle groups we present a Bayesian algorithm to separate surface EMG into representative motor unit action potentials. The algorithm is based upon differential Variable Component Analysis (dVCA) [l], [2] which was originally developed for Electroencephalograms. The algorithm uses a simple forward model representing a mixture of motor unit action potentials as seen across multiple channels. The parameters of this model are iteratively optimized for each component. Results are presented on both synthetic and experimental EMG data. The synthetic case has additive white noise and is compared with known components. The experimental EMG data was obtained using a custom linear electrode array designed for this study.

  18. Objective models of EMG signals for cyclic processes such as a human gait

    NASA Astrophysics Data System (ADS)

    Babska, Luiza; Selegrat, Monika; Dusza, Jacek J.

    2016-09-01

    EMG signals are small potentials appearing at the surface of human skin during muscle work. They arise due to changes in the physiological state of cell membranes in the muscle fibers. They are characterized by a relatively low frequency range (500 Hz) and a low amplitude signal (of the order of μV), making it difficult to record. Raw EMG signal is inherently random shape. However we can distinguish certain features related to the activation of the muscles of a deterministic or quasi-deterministic associated with the movement and its parametric description. Objective models of EMG signals were created on the base of actual data obtained from the VICON system installed at the University of Physical Education in Warsaw. The object of research (healthy woman) moved repeatedly after a fixed track. On her body 35 reflective markers to record the gait kinematics and 8 electrodes to record EMG signals were placed. We obtained research data included more than 1,000 EMG signals synchronized with the phases of gait. Test result of the work is an algorithm for obtaining the average EMG signal received from the multiple registration gait cycles carried out in the same reproducible conditions. The method described in the article is essentially a pre-finding measurement data from the two quasi-synchronous signals at different sampling frequencies for further processing. This signal is characterized by a significant reduction of high frequency noise and emphasis on the specific characteristics of individual records found in muscle activity.

  19. Surface EMG of jaw elevator muscles: effect of electrode location and inter-electrode distance.

    PubMed

    Castroflorio, T; Farina, D; Bottin, A; Piancino, M G; Bracco, P; Merletti, R

    2005-06-01

    This study addresses methodological issues on surface electromyographic (EMG) signal recording from jaw elevator muscles. The aims were (i) to investigate the sensitivity to electrode displacements of amplitude and spectral surface EMG variables, (ii) to analyse if this sensitivity is affected by the inter-electrode distance of the bipolar recording, and (iii) to investigate the effect of inter-electrode distance on the estimated amplitude and spectral EMG variables. The superficial masseter and anterior temporalis muscles of 13 subjects were investigated by means of a linear electrode array. The percentage difference in EMG variable estimates from signals detected at different locations over the muscle was larger than 100% of the estimated value. Increasing the inter-electrode distance resulted in a significant reduction of the estimation variability because of electrode displacement. A criterion for electrode placement selection is suggested, with which the sensitivity of EMG variables to small electrode displacements was of the order of 2% for spectral and 6% for amplitude variables. Finally, spectral and, in particular, amplitude EMG variables were very sensitive to inter-electrode distance, which thus should be fixed when subjects or muscles are compared in the same or different experimental conditions.

  20. Feature extraction of the first difference of EMG time series for EMG pattern recognition.

    PubMed

    Phinyomark, Angkoon; Quaine, Franck; Charbonnier, Sylvie; Serviere, Christine; Tarpin-Bernard, Franck; Laurillau, Yann

    2014-11-01

    This paper demonstrates the utility of a differencing technique to transform surface EMG signals measured during both static and dynamic contractions such that they become more stationary. The technique was evaluated by three stationarity tests consisting of the variation of two statistical properties, i.e., mean and standard deviation, and the reverse arrangements test. As a result of the proposed technique, the first difference of EMG time series became more stationary compared to the original measured signal. Based on this finding, the performance of time-domain features extracted from raw and transformed EMG was investigated via an EMG classification problem (i.e., eight dynamic motions and four EMG channels) on data from 18 subjects. The results show that the classification accuracies of all features extracted from the transformed signals were higher than features extracted from the original signals for six different classifiers including quadratic discriminant analysis. On average, the proposed differencing technique improved classification accuracies by 2-8%.

  1. Relationship between the MRI and EMG measurements.

    PubMed

    Kubota, J; Ono, T; Araki, M; Tawara, N; Torii, S; Okuwaki, T; Fukubayashi, T

    2009-07-01

    The purpose of this study was to investigate the effect of intensive eccentric exercise on hamstring muscles by using magnetic resonance imaging (MRI) and to elucidate the relationships between the changes in the electromyographic (EMG) parameters and in the transverse relaxation time (T2) of the hamstring muscles. Seven male volunteers performed eccentric knee flexion exercise, and the EMG activity of the hamstring muscles was simultaneously measured. Before and immediately after the exercise, the maximum isometric knee flexion torque was measured and MR images of the hamstring muscles were obtained. For all hamstring muscles, the EMG activity of the fifth set was significantly lower than that of the first set. For each subject, a significant correlation was detected between the percentage change in the value of the post-exercise T2 value and those of EMG signals during the exercise only for the semitendinosus (ST) muscle and not for the biceps femoris (BF) and the semimembranosus (SM) muscles. These results suggested that the EMG-activity reductions in the BF, ST, and SM muscles were due to neuromuscular fatigue, and moreover the reduction in the ST muscle was due to a failure in the E-C coupling, which was caused by excessive muscle-fiber damage.

  2. Variability of ICA decomposition may impact EEG signals when used to remove eyeblink artifacts.

    PubMed

    Pontifex, Matthew B; Gwizdala, Kathryn L; Parks, Andrew C; Billinger, Martin; Brunner, Clemens

    2017-03-01

    Despite the growing use of independent component analysis (ICA) algorithms for isolating and removing eyeblink-related activity from EEG data, we have limited understanding of how variability associated with ICA uncertainty may be influencing the reconstructed EEG signal after removing the eyeblink artifact components. To characterize the magnitude of this ICA uncertainty and to understand the extent to which it may influence findings within ERP and EEG investigations, ICA decompositions of EEG data from 32 college-aged young adults were repeated 30 times for three popular ICA algorithms. Following each decomposition, eyeblink components were identified and removed. The remaining components were back-projected, and the resulting clean EEG data were further used to analyze ERPs. Findings revealed that ICA uncertainty results in variation in P3 amplitude as well as variation across all EEG sampling points, but differs across ICA algorithms as a function of the spatial location of the EEG channel. This investigation highlights the potential of ICA uncertainty to introduce additional sources of variance when the data are back-projected without artifact components. Careful selection of ICA algorithms and parameters can reduce the extent to which ICA uncertainty may introduce an additional source of variance within ERP/EEG studies.

  3. Acoustic (loudspeaker) facial EMG monitoring: II. Use of evoked EMG activity during acoustic neuroma resection.

    PubMed

    Prass, R L; Kinney, S E; Hardy, R W; Hahn, J F; Lüders, H

    1987-12-01

    Facial electromyographic (EMG) activity was continuously monitored via loudspeaker during eleven translabyrinthine and nine suboccipital consecutive unselected acoustic neuroma resections. Ipsilateral facial EMG activity was synchronously recorded on the audio channels of operative videotapes, which were retrospectively reviewed in order to allow detailed evaluation of the potential benefit of various acoustic EMG patterns in the performance of specific aspects of acoustic neuroma resection. The use of evoked facial EMG activity was classified and described. Direct local mechanical (surgical) stimulation and direct electrical stimulation were of benefit in the localization and/or delineation of the facial nerve contour. Burst and train acoustic patterns of EMG activity appeared to indicate surgical trauma to the facial nerve that would not have been appreciated otherwise. Early results of postoperative facial function of monitored patients are presented, and the possible value of burst and train acoustic EMG activity patterns in the intraoperative assessment of facial nerve function is discussed. Acoustic facial EMG monitoring appears to provide a potentially powerful surgical tool for delineation of the facial nerve contour, the ongoing use of which may lead to continued improvement in facial nerve function preservation through modification of dissection strategy.

  4. An EMG study on TMJ disorders.

    PubMed

    Valentino, B; Aldi, B; Melito, F; Valentino, T

    2002-01-01

    The Authors have described a clinical case involving a patient with a classical TMJ syndrome and a full range of typical symptoms, both dental and non-dental. The patient underwent a set of EMG tests before his occlusal plane was restored using a special material, immediately following reconstruction and, lastly, three months following the application of a prosthesis. The findings of these EMG tests have shown that the complex symptoms reported by the patient could be traced back to his occlusal plane. Once it was reconstructed, all the typical dental and non-dental symptoms of TMJ disorders subsided.

  5. Syllable-based speech recognition using EMG.

    PubMed

    Lopez-Larraz, Eduardo; Mozos, Oscar M; Antelis, Javier M; Minguez, Javier

    2010-01-01

    This paper presents a silent-speech interface based on electromyographic (EMG) signals recorded in the facial muscles. The distinctive feature of this system is that it is based on the recognition of syllables instead of phonemes or words, which is a compromise between both approaches with advantages as (a) clear delimitation and identification inside a word, and (b) reduced set of classification groups. This system transforms the EMG signals into robust-in-time feature vectors and uses them to train a boosting classifier. Experimental results demonstrated the effectiveness of our approach in three subjects, providing a mean classification rate of almost 70% (among 30 syllables).

  6. Low-Amplitude Craniofacial EMG Power Spectral Density and 3D Muscle Reconstruction from MRI

    PubMed Central

    Wiedemann, Lukas; Chaberova, Jana; Edmunds, Kyle; Einarsdóttir, Guðrún; Ramon, Ceon

    2015-01-01

    Improving EEG signal interpretation, specificity, and sensitivity is a primary focus of many current investigations, and the successful application of EEG signal processing methods requires a detailed knowledge of both the topography and frequency spectra of low-amplitude, high-frequency craniofacial EMG. This information remains limited in clinical research, and as such, there is no known reliable technique for the removal of these artifacts from EEG data. The results presented herein outline a preliminary investigation of craniofacial EMG high-frequency spectra and 3D MRI segmentation that offers insight into the development of an anatomically-realistic model for characterizing these effects. The data presented highlights the potential for confounding signal contribution from around 60 to 200 Hz, when observed in frequency space, from both low and high-amplitude EMG signals. This range directly overlaps that of both low γ (30-50 Hz) and high γ (50-80 Hz) waves, as defined traditionally in standatrd EEG measurements, and mainly with waves presented in dense-array EEG recordings. Likewise, average EMG amplitude comparisons from each condition highlights the similarities in signal contribution of low-activity muscular movements and resting, control conditions. In addition to the FFT analysis performed, 3D segmentation and reconstruction of the craniofacial muscles whose EMG signals were measured was successful. This recapitulation of the relevant EMG morphology is a crucial first step in developing an anatomical model for the isolation and removal of confounding low-amplitude craniofacial EMG signals from EEG data. Such a model may be eventually applied in a clinical setting to ultimately help to extend the use of EEG in various clinical roles. PMID:26913150

  7. Motor unit size in muscular dystrophy, a macro EMG and scanning EMG study.

    PubMed Central

    Hilton-Brown, P; Stålberg, E

    1983-01-01

    Patients with muscular dystrophy were investigated with Macro EMG to study activity from whole individual motor units, and with Scanning EMG to study the distribution of activity within the motor unit. Macro motor unit potentials were normal or only slightly reduced in amplitude. In Scanning EMG the units had unchanged mean length compared with normal, but an uneven distribution of the activity. This was also seen in severely weak muscles. The findings are interpreted to be the result of degenerative and regenerative processes, giving rise to remodelling of the motor unit. Images PMID:6655485

  8. Influence of different attentional focus on EMG amplitude and contraction duration during the bench press at different speeds.

    PubMed

    Calatayud, Joaquin; Vinstrup, Jonas; Jakobsen, Markus D; Sundstrup, Emil; Colado, Juan Carlos; Andersen, Lars L

    2017-08-10

    The purpose of this study was to investigate whether using different focus affects electromyographic (EMG) amplitude and contraction duration during bench press performed at explosive and controlled speeds. Eighteen young male individuals were familiarized with the procedure and performed the one-maximum repetition (1RM) test in the first session. In the second session, participants performed the bench press exercise at 50% of the 1RM with 3 different attentional focuses (regular focus on moving the load vs contracting the pectoralis vs contracting the triceps) at 2 speed conditions (controlled vs maximal speed). During the controlled speed condition, focusing on using either the pectoralis or the triceps muscles increased pectoralis normalized EMG (nEMG) by 6% (95% CI 3-8%; p = 0.0001) and 4% nEMG (95% CI 1-7%; p = 0.0096), respectively, compared with the regular focus condition. Triceps activity was increased by 4% nEMG (95% CI 0-7%; p = 0.0308) at the controlled speed condition during the triceps focus. During the explosive speed condition, the use of different focuses had no effect. The different attentional focus resulted in comparable contraction duration for the measured muscles when the exercise was performed explosively. Using internal focus to increase EMG amplitude seems to function only during conditions of controlled speed.

  9. Comparison and reproducibility of sEMG during manual muscle testing on land and in water.

    PubMed

    Silvers, W Matthew; Dolny, Dennis G

    2011-02-01

    The objectives of this study were to: (1) compare the sEMG recordings from maximal voluntary contractions (MVC), and (2) examine the reproducibility of sEMG recordings from MVCs for selected lower extremity muscles derived from manual muscle testing (MMT) on dry land, and in water prior to and following aquatic treadmill running. Twelve healthy recreational male runners participated. The selected muscles were: M. quadriceps-vastus medialis (VM) and rectus femoris (RF), M. biceps femoris (BF), M. tibialis anterior (TA) and the M. gastrocnemius caput mediale (GAS) of the right leg. The MVC testing conditions were: dry land, underwater prior to (Water 1) and following an aquatic exercise trial (Water 2). For each muscle, a one-way analysis of variance with repeated measures was used to compare MVC scores between testing conditions, and the intra-class correlation coefficient (ICC) and typical error (CV%) were calculated to determine the reproducibility and precision of MVC scores, respectively, between conditions. For all muscles, no significant differences were observed between land and water MVC scores (p=0.88-0.97), and high reliability (ICC=0.96-0.98) and precision (CV%=7.4-12.6%) were observed between MVC conditions. Under MMT conditions it appears that comparable MVC sEMG values were achieved on land and in water and the integrity of the EMG recordings were maintained during water immersion. Future studies using sEMG waterproofing procedures should conduct MVC testing in water for data normalization and perform post-exercise verification of sEMG signal integrity.

  10. Cerebral potentials and leg muscle e.m.g. responses associated with stance perturbation.

    PubMed

    Dietz, V; Quintern, J; Berger, W; Schenck, E

    1985-01-01

    In order to investigate the neuronal mechanisms underlying the compensatory movements following stance disturbance, leg muscle e.m.g. responses and cerebral potentials evoked by a treadmill acceleration impulse were analysed. It was found that the displacement was followed by a cerebral potential of a latency of 40-45 ms and EMG responses in the calf muscles at a latency of 65-70 ms. The e.m.g. responses represented specific compensatory reactions to the mode of perturbation (with a gastrocnemius activation following positive acceleration but a tibialis ant. activation following negative acceleration). The cerebral potentials, however, showed a common pattern to both conditions. In addition, the leg muscle e.m.g. reactions were not altered by learning effects and by forewarning of displacement onset, while the amplitude of the cerebral potentials was significantly smaller in these conditions compared to those produced in response to randomly induced perturbations. It was therefore concluded that the leg muscle e.m.g. reactions are mediated by a polysynaptic spinal reflex pathway which depends on a supraspinal control. The cerebral potentials seem to represent afferent signals which can be supposed to be subjected to modification and processing by supraspinal motor centres, according to the actual requirements.

  11. Detection of the onset of gait initiation using kinematic sensors and EMG in transfemoral amputees.

    PubMed

    Wentink, E C; Schut, V G H; Prinsen, E C; Rietman, J S; Veltink, P H

    2014-01-01

    In this study we determined if detection of the onset of gait initiation in transfemoral amputees can be useful for voluntary control of upper leg prostheses. From six transfemoral amputees inertial sensor data and EMG were measured at the prosthetic leg during gait initiation. First, initial movement was detected from the inertial sensor data. Subsequently it was determined whether EMG could predict initial movement before detection based on the inertial sensors with comparable consistency as the inertial sensors. From the inertial sensors the initial movement can be determined. If the prosthetic leg leads, the upper leg accelerometer data was able to detect initial movement best. If the intact leg leads the upper leg gyroscope data performed best. Inertial sensors at the upper leg in general showed detections at the same time or earlier than those at the lower leg. EMG can predict initial movement up to a 138 ms in advance, when the prosthetic leg leads. One subject showed consistent EMG onset up to 248 ms before initial movement in the intact leg leading condition. A new method to detect initial movement from inertial sensors was presented and can be useful for additional prosthetic control. EMG measured at the prosthetic leg can be used for prediction of gait initiation when the prosthetic leg is leading, but for the intact leg leading condition this will not be of additional value.

  12. Effects of subthalamic nucleus stimulation on characteristics of EMG activity underlying reaction time in Parkinson's disease.

    PubMed

    Kumru, Hatice; Summerfield, Christopher; Valldeoriola, Francesc; Valls-Solé, Josep

    2004-01-01

    We examined the effects of high-frequency deep brain stimulation of the subthalamic nucleus (STN-DBS) on characteristics of electromyographic (EMG) activity of the agonist muscle in 8 patients with Parkinson's disease (PD). Patients were examined during STN-DBS (ON), and 30 minutes after switching off both stimulators (OFF). They were asked to make a ballistic movement in paradigms of simple reaction time (SRT) and choice reaction time (CRT) tasks. Onset of movement (MOVonset) was measured as the latency of the initial displacement from baseline of the signal from an accelerometer attached to the dorsum of the hand. In the associated EMG activity, recorded from wrist extensor muscles, we measured onset latency (EMGonset), size of the first EMG burst (EMGsize), and number of EMG bursts (EMGbursts) counted between EMGonset and task execution. MOVonset and EMGonset were significantly shorter in ON than in OFF conditions in CRT. EMGsize was larger, EMGbursts were reduced, and peak of the acceleration profile was larger in ON compared with OFF conditions in both SRT and CRT. Our results indicate that STN-DBS induces a significant improvement in motor performance of reaction time tasks in PD patients. Such improvement is associated with a change in features of the EMG activity suggesting an increase in the excitability of the motor pathways engaged in ballistic movements.

  13. Examination of extrinsic foot muscles during running using mfMRI and EMG.

    PubMed

    O'Connor, Kristian M; Price, Thomas B; Hamill, Joseph

    2006-10-01

    Over-pronation has been cited as a key contributor to many types of running injuries. However, the roles of the extrinsic foot muscles during running have not been adequately identified. The purpose of this study was to examine the muscle functional (mf) MRI and EMG responses to perturbations of the foot by running in varus, neutral and valgus wedged shoes. Ten males ran at 3.6 m/s in specially constructed shoes for 5 min with T2-weighted mfMRI collected before and after each run. The change in T2 from before to after each run characterized the level of metabolic activity in each of muscle. Kinematic and EMG data were also collected while subjects ran on a treadmill. There were no T2 differences across the three shoe conditions. In contrast, there was significantly less EMG activity in the tibialis anterior and soleus while wearing the neutral shoe. Overall, the results did not support the theory that muscle activity would increase as the degree of eversion increased. It also appears that surface EMG was more sensitive to differences between conditions than mfMRI. However, this study illustrated that mfMRI may be a useful tool for quantifying muscle activity in cases where surface EMG is inadequate.

  14. The Response of Hyperkinesis to EMG Biofeedback.

    ERIC Educational Resources Information Center

    Haight, Maryellen J.; And Others

    A study was conducted involving eight hyperkinetic males (11-15 years old) to determine if Ss receiving electromyography (EMG) biofeedback training would show a reduction in frontalis muscle tension, hyperactivity, and lability, and increases in self-esteem and visual and auditory attention span. Individual 45- and 30-minute relaxation exercises…

  15. Surface EMG of jaw-elevator muscles and chewing pattern in complete denture wearers.

    PubMed

    Piancino, M G; Farina, D; Talpone, F; Castroflorio, T; Gassino, G; Margarino, V; Bracco, P

    2005-12-01

    The aim of this study was to investigate the adaptation process of masticatory patterns to a new complete denture in edentulous subjects. For this purpose, muscle activity and kinematic parameters of the chewing pattern were simultaneously assessed in seven patients with complete maxillary and mandibular denture. The patients were analysed (i) with the old denture, (ii) with the new denture at the delivery, (iii) after 1 month and (iv) after 3 months from the delivery of the new denture. Surface electromyographic (EMG) signals were recorded from the masseter and temporalis anterior muscles of both sides and jaw movements were tracked measuring the motion of a tiny magnet attached at the lower inter-incisor point. The subjects were asked to chew a bolus on the right and left side. At the delivery of the new denture, peak EMG amplitude of the masseter of the side of the bolus was lower than with the old denture and the masseters of the two sides showed the same intensity of EMG activity, contrary to the case with the old denture. EMG amplitude and asymmetry of the two masseter activities returned as with the old denture in 3 months. The EMG activity in the temporalis anterior was larger with the old denture than in the other conditions. The chewing cycle width and lateral excursion decreased at the delivery of the new denture and recovered after 3 months.

  16. EMG and acceleration signal analysis for quantifying the effects of medication in Parkinson's disease.

    PubMed

    Rissanen, Saara M; Kankaanpaa, Markku; Tarvainen, Mika P; Nuutinen, Juho; Airaksinen, Olavi; Karjalainen, Pasi A

    2011-01-01

    Parkinson's disease (PD) is characterized by motor disabilities that can be alleviated reasonably with appropriate medication. However, there is a lack of objective methods for quantifying the efficacy of treatment in PD. We applied here an objective method for quantifying the effects of medication in PD using EMG and acceleration measurements and analysis. In the method, four signal features were calculated from the EMG and acceleration recordings of both sides of the body: the kurtosis and recurrence rate of EMG, and the amplitude and sample entropy of acceleration. Principal component approach was used for reducing the number of variables. EMG and acceleration data measured from nine PD patients were used for analysis. The patients were measured in four different medication conditions: with medication off, and two and three and four hours after taking the medication. The results showed that in eight patients the EMG recordings changed into less spiky and the acceleration recordings into more complex after taking the medication. A reverse phenomenon in the signal characteristics was observed in seven patients 3-4 hours after taking the medication. The results indicate that the presented method is potentially useful for quantifying objectively the effects of medication on the neuromuscular function in PD.

  17. Evaluation of Novel EMG Biofeedback for Postural Correction During Computer Use.

    PubMed

    Gaffney, Brecca M; Maluf, Katrina S; Davidson, Bradley S

    2016-06-01

    Postural correction is an effective rehabilitation technique used to treat chronic neck and shoulder pain, and is aimed toward reducing the load on the surrounding muscles by adopting a neutral posture. The objective of this investigation was to evaluate the effectiveness of real-time high-density surface EMG (HDsEMG) biofeedback for postural correction during typing. Twenty healthy participants performed a typing task with two forms of postural feedback: (1) verbal postural coaching and (2) verbal postural coaching plus HDsEMG biofeedback. The interface used activity from two HDsEMG arrays placed over the trapezius designed to shift trapezius muscle activity inferiorly. The center of gravity across both arrays was used to quantify the spatial distribution of trapezius activity. Planar angles taken from upper extremity reflective markers quantified cervicoscapular posture. During the biofeedback condition, trapezius muscle activity was located 12.74 ± 3.73 mm more inferior, the scapula was 2.58 ± 1.18° more adducted and 0.23 ± 0.24° more depressed in comparison to verbal postural coaching alone. The results demonstrate the short-term effectiveness of a real-time HDsEMG biofeedback intervention to achieve postural correction, and may be more effective at creating an inferior shift in trapezius muscle activity in comparison to verbal postural coaching alone.

  18. Variation in EMG activity: a hierarchical approach

    PubMed Central

    German, Rebecca Z.; Crompton, A. W.; Thexton, A. J.

    2008-01-01

    Recordings of naturally occurring Electromyographic (EMG) signals are variable. One of the first formal and successful attempts to quantify variation in EMG signals was Shaffer and Lauder's (1985) study examining several levels of variation but not within muscle. The goal of the current study was to quantify the variation that exists at different levels, using more detailed measures of EMG activity than did Shaffer and Lauder (1985). The importance of accounting for different levels of variation in an EMG study is both biological and statistical. Signal variation within the same muscle for a stereotyped action suggests that each recording represents a sample drawn from a pool of a large number of motor units that, while biologically functioning in an integrated fashion, showed statistical variation. Different levels of variation for different muscles could be related to different functions or different tasks of those muscles. The statistical impact of unaccounted or inappropriately analyzed variation can lead to false rejection (type I error) or false acceptance (type II error) of the null hypothesis. Type II errors occur because such variation will accrue to the error, reducing power, and producing an artificially low F-value. Type I errors are associated with pseudoreplication, in which the replicated units are not truly independent, thereby leading to inflated degrees of freedom, and an underestimate of the error mean square. To address these problems, we used a repeated measures, nested multifactor model to measure the relative contribution of different hierarchical levels of variation to the total variation in EMG signals during swallowing. We found that variation at all levels, among electrodes in the same muscle, in sequences of the same animal, and among individuals and between differently named muscles, was significant. These findings suggest that a single intramuscular electrode, recording from a limited sample of the motor units, cannot be relied upon to

  19. Do all neuropathy patients need an EMG at least once?

    PubMed

    Smith, A Gordon

    2014-10-01

    EMG, which consists of nerve conduction studies and needle electromyography, is an essential diagnostic tool in the evaluation of patients with suspected peripheral neuropathy. Many neurologists order an EMG for all patients with suspected peripheral neuropathy. Not surprisingly, evidence now exists that shows EMG is a major driver of health care costs associated with neuropathy diagnoses. As neurologic practice evolves from fee for service to value-based compensation, neurologists will need to justify the diagnostic utility of EMG (outcome) relative to its cost. While carefully performed studies of diagnostic utility in many patient populations are lacking, a robust literature provides guidance regarding the potential role and limitations of EMG in neuropathy diagnosis as well as the pitfalls referring providers and electrodiagnostic consultants must consider. Do all neuropathy patients need an EMG at least once? This article attempts to answer this question using an illustrative case to highlight critical factors every neurologist must consider before ordering an EMG for neuropathy diagnosis.

  20. Assessment of low back muscle fatigue by surface EMG signal analysis: methodological aspects.

    PubMed

    Farina, Dario; Gazzoni, Marco; Merletti, Roberto

    2003-08-01

    This paper focuses on methodological issues related to surface electromyographic (EMG) signal detection from the low back muscles. In particular, we analysed (1) the characteristics (in terms of propagating components) of the signals detected from these muscles; (2) the effect of electrode location on the variables extracted from surface EMG; (3) the effect of the inter-electrode distance (IED) on the same variables; (4) the possibility of assessing fatigue during high and very low force level contractions. To address these issues, we detected single differential surface EMG signals by arrays of eight electrodes from six locations on the two sides of the spine, at the levels of the first (L1), the second (L2), and the fifth (L5) lumbar vertebra. In total, 42 surface EMG channels were acquired at the same time during both high and low force, short and long duration contractions. The main results were: (1) signal quality is poor with predominance of non-travelling components; (2) as a consequence of point (1), in the majority of the cases it is not possible to reliably estimate muscle fiber conduction velocity; (3) despite the poor signal quality, it was possible to distinguish the fatigue properties of the investigated muscles and the fatigability at different contraction levels; (4) IED affects the sensitivity of surface EMG variables to electrode location and large IEDs are suggested when spectral and amplitude analysis is performed; (5) the sensitivity of surface EMG variables to changes in electrode location is on average larger than for other muscles with less complex architecture; (6) IED influences amplitude initial values and slopes, and spectral variable initial values; (7) normalized slopes for both amplitude and spectral variables are not affected by IED and, thus, are suggested for fatigue analysis at different postures or during movement, when IED may change in different conditions (in case of separated electrodes); (8) the surface EMG technique at the

  1. Error reduction in EMG signal decomposition.

    PubMed

    Kline, Joshua C; De Luca, Carlo J

    2014-12-01

    Decomposition of the electromyographic (EMG) signal into constituent action potentials and the identification of individual firing instances of each motor unit in the presence of ambient noise are inherently probabilistic processes, whether performed manually or with automated algorithms. Consequently, they are subject to errors. We set out to classify and reduce these errors by analyzing 1,061 motor-unit action-potential trains (MUAPTs), obtained by decomposing surface EMG (sEMG) signals recorded during human voluntary contractions. Decomposition errors were classified into two general categories: location errors representing variability in the temporal localization of each motor-unit firing instance and identification errors consisting of falsely detected or missed firing instances. To mitigate these errors, we developed an error-reduction algorithm that combines multiple decomposition estimates to determine a more probable estimate of motor-unit firing instances with fewer errors. The performance of the algorithm is governed by a trade-off between the yield of MUAPTs obtained above a given accuracy level and the time required to perform the decomposition. When applied to a set of sEMG signals synthesized from real MUAPTs, the identification error was reduced by an average of 1.78%, improving the accuracy to 97.0%, and the location error was reduced by an average of 1.66 ms. The error-reduction algorithm in this study is not limited to any specific decomposition strategy. Rather, we propose it be used for other decomposition methods, especially when analyzing precise motor-unit firing instances, as occurs when measuring synchronization.

  2. Error reduction in EMG signal decomposition

    PubMed Central

    Kline, Joshua C.

    2014-01-01

    Decomposition of the electromyographic (EMG) signal into constituent action potentials and the identification of individual firing instances of each motor unit in the presence of ambient noise are inherently probabilistic processes, whether performed manually or with automated algorithms. Consequently, they are subject to errors. We set out to classify and reduce these errors by analyzing 1,061 motor-unit action-potential trains (MUAPTs), obtained by decomposing surface EMG (sEMG) signals recorded during human voluntary contractions. Decomposition errors were classified into two general categories: location errors representing variability in the temporal localization of each motor-unit firing instance and identification errors consisting of falsely detected or missed firing instances. To mitigate these errors, we developed an error-reduction algorithm that combines multiple decomposition estimates to determine a more probable estimate of motor-unit firing instances with fewer errors. The performance of the algorithm is governed by a trade-off between the yield of MUAPTs obtained above a given accuracy level and the time required to perform the decomposition. When applied to a set of sEMG signals synthesized from real MUAPTs, the identification error was reduced by an average of 1.78%, improving the accuracy to 97.0%, and the location error was reduced by an average of 1.66 ms. The error-reduction algorithm in this study is not limited to any specific decomposition strategy. Rather, we propose it be used for other decomposition methods, especially when analyzing precise motor-unit firing instances, as occurs when measuring synchronization. PMID:25210159

  3. An EMG-based robot control scheme robust to time-varying EMG signal features.

    PubMed

    Artemiadis, Panagiotis K; Kyriakopoulos, Kostas J

    2010-05-01

    Human-robot control interfaces have received increased attention during the past decades. With the introduction of robots in everyday life, especially in providing services to people with special needs (i.e., elderly, people with impairments, or people with disabilities), there is a strong necessity for simple and natural control interfaces. In this paper, electromyographic (EMG) signals from muscles of the human upper limb are used as the control interface between the user and a robot arm. EMG signals are recorded using surface EMG electrodes placed on the user's skin, making the user's upper limb free of bulky interface sensors or machinery usually found in conventional human-controlled systems. The proposed interface allows the user to control in real time an anthropomorphic robot arm in 3-D space, using upper limb motion estimates based only on EMG recordings. Moreover, the proposed interface is robust to EMG changes with respect to time, mainly caused by muscle fatigue or adjustments of contraction level. The efficiency of the method is assessed through real-time experiments, including random arm motions in the 3-D space with variable hand speed profiles.

  4. Intention-based EMG control for powered exoskeletons.

    PubMed

    Lenzi, T; De Rossi, S M M; Vitiello, N; Carrozza, M C

    2012-08-01

    Electromyographical (EMG) signals have been frequently used to estimate human muscular torques. In the field of human-assistive robotics, these methods provide valuable information to provide effectively support to the user. However, their usability is strongly limited by the necessity of complex user-dependent and session-dependent calibration procedures, which confine their use to the laboratory environment. Nonetheless, an accurate estimate of muscle torque could be unnecessary to provide effective movement assistance to users. The natural ability of human central nervous system of adapting to external disturbances could compensate for a lower accuracy of the torque provided by the robot and maintain the movement accuracy unaltered, while the effort is reduced. In order to explore this possibility, in this paper we study the reaction of ten healthy subjects to the assistance provided through a proportional EMG control applied by an elbow powered exoskeleton. This system gives only a rough estimate of the user muscular torque but does not require any specific calibration. Experimental results clearly show that subjects adapt almost instantaneously to the assistance provided by the robot and can reduce their effort while keeping full control of the movement under different dynamic conditions (i.e., no alterations of movement accuracy are observed).

  5. Prefrontal oxygenation and the acoustic startle eyeblink response during exercise: A test of the dual-mode model.

    PubMed

    Tempest, Gavin D; Parfitt, Gaynor

    2017-03-30

    The interplay between the prefrontal cortex and amygdala is proposed to explain the regulation of affective responses (pleasure/displeasure) during exercise as outlined in the dual-mode model. However, due to methodological limitations the dual-mode model has not been fully tested. In this study, prefrontal oxygenation (using near-infrared spectroscopy) and amygdala activity (reflected by eyeblink amplitude using acoustic startle methodology) were recorded during exercise standardized to metabolic processes: 80% of ventilatory threshold (below VT), at the VT, and at the respiratory compensation point (RCP). Self-reported tolerance of the intensity of exercise was assessed prior to, and affective responses recorded during exercise. The results revealed that, as the intensity of exercise became more challenging (from below VT to RCP), prefrontal oxygenation was larger and eyeblink amplitude and affective responses were reduced. Below VT and at VT, larger prefrontal oxygenation was associated with larger eyeblink amplitude. At the RCP, prefrontal oxygenation was greater in the left than right hemisphere, and eyeblink amplitude explained significant variance in affective responses (with prefrontal oxygenation) and self-reported tolerance. These findings highlight the role of the prefrontal cortex and potentially the amygdala in the regulation of affective (particularly negative) responses during exercise at physiologically challenging intensities (above VT). In addition, a psychophysiological basis of self-reported tolerance is indicated. This study provides some support of the dual-mode model and insight into the neural basis of affective responses during exercise.

  6. Both Trace and Delay Conditioning of Evaluative Responses Depend on Contingency Awareness

    ERIC Educational Resources Information Center

    Kattner, Florian; Ellermeier, Wolfgang; Tavakoli, Paniz

    2012-01-01

    Whereas previous evaluative conditioning (EC) studies produced inconsistent results concerning the role of contingency knowledge, there are classical eye-blink conditioning studies suggesting that declarative processes are involved in trace conditioning but not in delay conditioning. In two EC experiments pairing neutral sounds (conditioned…

  7. [Electromyographic (EMG) electrode impedance and EMG activity from anterior temporal muscle and masseter muscle].

    PubMed

    Takarada, T; Alvarado Larrinaga, G; Nishida, F; Nishino, M

    1989-01-01

    The value and change with time of the impedance of surface EMG electrodes and the effects of their difference between the bipolar electrodes on the electromyographic activity from the anterior temporal muscle and the masseter muscle in six adult male subjects with normal occlusion were studied. The results were as follows: 1. In the anterior temporal muscle, if the impedance of the electrode was under 20 k omega it was stable from just after the electrode disc was applied to the skin. In the masseter muscle, if the impedance was under 30 k omega it became stable within two minutes after the electrode was applied. 2. The difference of impedance between the bipolar EMG electrodes did not correlate with EMG activity.

  8. Effect of toe extension on EMG of triceps surae muscles during isometric dorsiflexion.

    PubMed

    Siddiqi, Ariba; Arjunan, Sridhar P; Kumar, Dinesh

    2016-12-01

    The protocol for estimating force of contraction by triceps surae (TS) muscles requires the immobilization of the ankle during dorsiflexion and plantar flexion. However, large variability in the results has been observed. To identify the cause of this variability, experiments were conducted where ankle dorsiflexion force and electromyogram (EMG) of the TS were recorded under two conditions: (i) toes were strapped and (ii) toes were unstrapped, with all other conditions such as immobilization of the ankle remaining unchanged. The root mean square (RMS) of the EMG and the force were analyzed and one-tail Student's t-test was performed for significance between the two conditions. The RMS of the EMG from TS muscles was found to be significantly higher (~55%) during dorsiflexion with toes unstrapped compared with when the toes were strapped. The torque corresponding to dorsiflexion was also higher with toes unstrapped. Our study has shown that it is important to strap the toes when measuring the torque at the ankle and EMG of the TS muscles.

  9. Design of sEMG assembly to detect external anal sphincter activity: a proof of concept.

    PubMed

    Shiraz, Arsam; Leaker, Brian; Mosse, Charles Alexander; Solomon, Eskinder; Craggs, Michael; Demosthenous, Andreas

    2017-09-13

    Conditional trans-rectal stimulation of the pudendal nerve could provide a viable solution to treat hyperreflexive bladder in spinal cord injury. A set threshold of the amplitude estimate of the external anal sphincter surface electromyography (sEMG) may be used as the trigger signal. The efficacy of such a device should be tested in a large scale clinical trial. As such a probe should remain in situ for several hours while patients attend to their daily routine, the recording electrodes should be designed to be large enough to maintain good contact while observing design constraints. The objective of this study was to arrive at a design for intra-anal sEMG recording electrodes for the subsequent clinical trials while deriving the possible recording and processing parameters. Approach: Having in mind existing solutions and based on theoretical and anatomical considerations, a set of four multi-electrode probes were designed and developed. These were tested in a healthy subject and the measured sEMG traces were recorded and appropriately processed. Main results: It was shown that while comparatively large electrodes record sEMG traces that are not sufficiently correlated with the external anal sphincter contractions, smaller electrodes may not maintain a stable electrode tissue contact. It was shown that 3 mm wide and 1 cm long electrodes with 5 mm inter-electrode spacing, in agreement with Nyquist sampling, placed 1 cm from the orifice may intra-anally record a sEMG trace sufficiently correlated with external anal sphincter activity. Significance: The outcome of this study can be used in any biofeedback, treatment or diagnostic application where the activity of the external anal sphincter sEMG should be detected for an extended period of time. . © 2017 Institute of Physics and Engineering in Medicine.

  10. Evoked EMG-based torque prediction under muscle fatigue in implanted neural stimulation

    NASA Astrophysics Data System (ADS)

    Hayashibe, Mitsuhiro; Zhang, Qin; Guiraud, David; Fattal, Charles

    2011-10-01

    In patients with complete spinal cord injury, fatigue occurs rapidly and there is no proprioceptive feedback regarding the current muscle condition. Therefore, it is essential to monitor the muscle state and assess the expected muscle response to improve the current FES system toward adaptive force/torque control in the presence of muscle fatigue. Our team implanted neural and epimysial electrodes in a complete paraplegic patient in 1999. We carried out a case study, in the specific case of implanted stimulation, in order to verify the corresponding torque prediction based on stimulus evoked EMG (eEMG) when muscle fatigue is occurring during electrical stimulation. Indeed, in implanted stimulation, the relationship between stimulation parameters and output torques is more stable than external stimulation in which the electrode location strongly affects the quality of the recruitment. Thus, the assumption that changes in the stimulation-torque relationship would be mainly due to muscle fatigue can be made reasonably. The eEMG was proved to be correlated to the generated torque during the continuous stimulation while the frequency of eEMG also decreased during fatigue. The median frequency showed a similar variation trend to the mean absolute value of eEMG. Torque prediction during fatigue-inducing tests was performed based on eEMG in model cross-validation where the model was identified using recruitment test data. The torque prediction, apart from the potentiation period, showed acceptable tracking performances that would enable us to perform adaptive closed-loop control through implanted neural stimulation in the future.

  11. Muscle networks: Connectivity analysis of EMG activity during postural control

    NASA Astrophysics Data System (ADS)

    Boonstra, Tjeerd W.; Danna-Dos-Santos, Alessander; Xie, Hong-Bo; Roerdink, Melvyn; Stins, John F.; Breakspear, Michael

    2015-12-01

    Understanding the mechanisms that reduce the many degrees of freedom in the musculoskeletal system remains an outstanding challenge. Muscle synergies reduce the dimensionality and hence simplify the control problem. How this is achieved is not yet known. Here we use network theory to assess the coordination between multiple muscles and to elucidate the neural implementation of muscle synergies. We performed connectivity analysis of surface EMG from ten leg muscles to extract the muscle networks while human participants were standing upright in four different conditions. We observed widespread connectivity between muscles at multiple distinct frequency bands. The network topology differed significantly between frequencies and between conditions. These findings demonstrate how muscle networks can be used to investigate the neural circuitry of motor coordination. The presence of disparate muscle networks across frequencies suggests that the neuromuscular system is organized into a multiplex network allowing for parallel and hierarchical control structures.

  12. Design of microcontroller-based EMG and the analysis of EMG signals.

    PubMed

    Güler, Nihal Fatma; Hardalaç, Firat

    2002-04-01

    In this work, a microcontroller-based EMG designed and tested on 40 patients. When the patients are in rest, the fast Fourier transform (FFT) analysis was applied to EMG signals recorded from right leg peroneal region. The histograms are constructed from the results of the FFT analysis. The analysis results shows that the amplitude of fibrillation potential of the muscle fiber of 30 patients measured from peroneal region is low and the duration is short. This is the reason why the motor nerves degenerated and 10 patients were found to be healthy.

  13. Training-related changes in the EMG-moment relationship during isometric contractions: Further evidence of improved control of muscle activation in strength-trained men?

    PubMed

    Amarantini, David; Bru, Bertrand

    2015-08-01

    The possibility of using electromyography (EMG) to track muscle activity has raised the question of its relationship with the effort exerted by the muscles around the joints. However, the EMG-moment relationship is yet to be fully defined, and increasing knowledge of this topic could contribute to research in motor control and to the development of EMG-based algorithms and devices. With regards the training-related adaptations at the peripheral and central level, the present study investigated the effect of strength training on EMG-moment relationship. Our aim was to clarify its nature and gain further understanding of how morphological and neural factors may affect its form. The EMG-moment relationship was determined during knee flexion and extension isometric contractions performed by strength-trained male athletes and untrained male participants. The results showed that strength training induced linearity of the EMG-moment relationship concomitantly with enhanced maximum force production capacity and decreased co-activation of knee agonist-antagonist muscle pair. These results clarified discordant results regarding the linear or curved nature of the EMG-moment in isometric conditions and suggested that the remarkable linearity of the EMG-moment found in trained participants could indicate improved control of muscle activation.

  14. EMG patterns in abnormal involuntary movements induced by neuroleptics.

    PubMed

    Bathien, N; Koutlidis, R M; Rondot, P

    1984-09-01

    Electromyographic (EMG) activity of abnormal involuntary movements and their modifications after Piribedil, a dopaminergic agonist, were analysed in patients presenting with tremor or tardive dyskinesia induced by treatment with neuroleptics. Quantitative analysis of EMG bursts and of their phase relationships with bursts of antagonist muscles revealed differences between tremor and tardive dyskinesia; three separate EMG types of the latter were found. In tremor, EMG activity was coordinated between agonists and antagonists. Length and frequency of bursts are characteristic. In tardive dyskinesia, phase histograms of antagonist muscle bursts showed an absence of reciprocal organisation of EMG activity. This activity was made up of either rhythmical bursts (type I and II according to the frequency) or irregular discharges (type III). Piribedil decreased tremor but facilitated EMG activity in tardive dyskinesia. These results give an objective measurement or classification of tremor and tardive dyskinesia induced by neuroleptics.

  15. EMG patterns in abnormal involuntary movements induced by neuroleptics.

    PubMed Central

    Bathien, N; Koutlidis, R M; Rondot, P

    1984-01-01

    Electromyographic (EMG) activity of abnormal involuntary movements and their modifications after Piribedil, a dopaminergic agonist, were analysed in patients presenting with tremor or tardive dyskinesia induced by treatment with neuroleptics. Quantitative analysis of EMG bursts and of their phase relationships with bursts of antagonist muscles revealed differences between tremor and tardive dyskinesia; three separate EMG types of the latter were found. In tremor, EMG activity was coordinated between agonists and antagonists. Length and frequency of bursts are characteristic. In tardive dyskinesia, phase histograms of antagonist muscle bursts showed an absence of reciprocal organisation of EMG activity. This activity was made up of either rhythmical bursts (type I and II according to the frequency) or irregular discharges (type III). Piribedil decreased tremor but facilitated EMG activity in tardive dyskinesia. These results give an objective measurement or classification of tremor and tardive dyskinesia induced by neuroleptics. PMID:6148381

  16. Techniques of EMG signal analysis: detection, processing, classification and applications

    PubMed Central

    Hussain, M.S.; Mohd-Yasin, F.

    2006-01-01

    Electromyography (EMG) signals can be used for clinical/biomedical applications, Evolvable Hardware Chip (EHW) development, and modern human computer interaction. EMG signals acquired from muscles require advanced methods for detection, decomposition, processing, and classification. The purpose of this paper is to illustrate the various methodologies and algorithms for EMG signal analysis to provide efficient and effective ways of understanding the signal and its nature. We further point up some of the hardware implementations using EMG focusing on applications related to prosthetic hand control, grasp recognition, and human computer interaction. A comparison study is also given to show performance of various EMG signal analysis methods. This paper provides researchers a good understanding of EMG signal and its analysis procedures. This knowledge will help them develop more powerful, flexible, and efficient applications. PMID:16799694

  17. Young, Healthy Subjects Can Reduce the Activity of Calf Muscles When Provided with EMG Biofeedback in Upright Stance

    PubMed Central

    Vieira, Taian M.; Baudry, Stéphane; Botter, Alberto

    2016-01-01

    Recent evidence suggests the minimization of muscular effort rather than of the size of bodily sway may be the primary, nervous system goal when regulating the human, standing posture. Different programs have been proposed for balance training; none however has been focused on the activation of postural muscles during standing. In this study we investigated the possibility of minimizing the activation of the calf muscles during standing through biofeedback. By providing subjects with an audio signal that varied in amplitude and frequency with the amplitude of surface electromyograms (EMG) recorded from different regions of the gastrocnemius and soleus muscles, we expected them to be able to minimize the level of muscle activation during standing without increasing the excursion of the center of pressure (CoP). CoP data and surface EMG from gastrocnemii, soleus and tibialis anterior muscles were obtained from 10 healthy participants while standing at ease and while standing with EMG biofeedback. Four sensitivities were used to test subjects' responsiveness to the EMG biofeedback. Compared with standing at ease, the two most sensitive feedback conditions induced a decrease in plantar flexor activity (~15%; P < 0.05) and an increase in tibialis anterior EMG (~10%; P < 0.05). Furthermore, CoP mean position significantly shifted backward (~30 mm). In contrast, the use of less sensitive EMG biofeedback resulted in a significant decrease in EMG activity of ankle plantar flexors with a marginal increase in TA activity compared with standing at ease. These changes were not accompanied by greater CoP displacements or significant changes in mean CoP position. Key results revealed subjects were able to keep standing stability while reducing the activity of gastrocnemius and soleus without loading their tibialis anterior muscle when standing with EMG biofeedback. These results may therefore posit the basis for the development of training protocols aimed at assisting subjects in

  18. Repeatability of surface EMG during gait in children

    PubMed Central

    Granata, Kevin P.; Padua, Darin A.; Abel, Mark F.

    2006-01-01

    Although mean amplitude and ON–OFF timing of muscle recruitment and electromyography (EMG) activation during gait is achieved by an age of six to eight years in normally developing children, recruitment dynamics illustrated by the shape of the EMG waveform may require continued developmental practice to achieve a stable pattern. Previous analyses have quantified the repeatability of the EMG waveform in adult subjects, but EMG variability for a pediatric population may be significantly different. The goal of this study was to quantify intra-session and inter-session variability in the phasic EMG waveform patterns from the lower limb muscles during self-selected speeds of walking in healthy-normal children for comparison with adult variability in gait EMG. The variance ratio quantifies the repeatability of the integrated EMG waveform shape in a group of normally-developing children. Results reveal that between-session EMG waveform variability were similar in adult and pediatric populations, but within-session variability for the children was approximately twice the published value for adults. Clinical implications of this pediatric EMG variability suggest cautious interpretation of data from limited trial samples or inter-session changes in performance of gait data. PMID:16274917

  19. Motor unit size estimation: confrontation of surface EMG with macro EMG.

    PubMed

    Roeleveld, K; Stegeman, D F; Falck, B; Stålberg, E V

    1997-06-01

    Surface EMG (SEMG) is little used for diagnostic purposes in clinical neurophysiology, mainly because it provides little direct information on individual motor units (MUs). One of the techniques to estimate the MU size is intra-muscular Macro EMG. The present study compares SEMG with Macro EMG. Fifty-eight channel SEMG was recorded simultaneously with Macro EMG. Individual MUPs were obtained by single fiber triggered averaging. All recordings were made from the biceps brachii of healthy subjects during voluntary contraction at low force. High positive correlations were found between all Macro and Surface motor unit potential (MUP) parameters: area, peak-to-peak amplitude, negative peak amplitude and positive peak amplitude. The MUPs recorded with SEMG were dependent on the distance between the MU and the skin surface. Normalizing the SEMG parameters for MU location did not improve the correlation coefficient between the parameters of both techniques. The two measurement techniques had almost the same relative range in MUP parameters in any individual subject compared to the others, especially after normalizing the surface MUP parameters for MU location. MUPs recorded with this type of SEMG provide useful information about the MU size.

  20. EMG-torque Relation in Chronic Stroke: A Novel EMG Complexity Representation with A Linear Electrode Array.

    PubMed

    Zhang, Xu; Wang, Dongqing; Yu, Zaiyang; Chen, Xiang; Li, Sheng; Zhou, Ping

    2016-11-08

    This study examines the electromyogram (EMG) - torque relation for chronic stroke survivors using a novel EMG complexity representation. Ten stroke subjects performed a series of submaximal isometric elbow flexion tasks using their affected and contralateral arms, respectively, while a 20-channel linear electrode array was used to record surface EMG from the biceps brachii muscles. The sample entropy (SampEn) of surface EMG signals was calculated with both global and local tolerance schemes. A regression analysis was performed between SampEn of each channel's surface EMG and elbow flexion torque. It was found that a linear regression can be used to well describe the relation between surface EMG SampEn and the torque. Each channel's root mean square (RMS) amplitude of surface EMG signal in the different torque level was computed to determine the channel with the highest EMG amplitude. The slope of the regression (observed from the channel with the highest EMG amplitude) was smaller on the impaired side than on the non-impaired side in 8 of the 10 subjects, regardless of the tolerance scheme (global or local) and the range of torques (full or matched range) used for comparison. The surface EMG signals from the channels above the estimated muscle innervation zones demonstrated significantly lower levels of complexity compared with other channels between innervation zones and muscle tendons. The study provides a novel point of view of the EMG-torque relation in the complexity domain, and reveals its alterations post stroke, which are associated with complex neural and muscular changes post stroke. The slope difference between channels with regard to innervation zones also confirms the relevance of electrode position in surface EMG analysis.

  1. Surface EMG based muscle activity analysis for aerobic cyclist.

    PubMed

    Balasubramanian, Venkatesh; Jayaraman, Srinivasan

    2009-01-01

    In this study, we determined the muscle activity of aerobic cyclist on biceps brachii medial, trapezius medial, latissimus dorsi medial, and erector spinae muscles bilaterally during 30 min of cycling. Thirteen male volunteers were chosen and placed in two groups (with and without low back pain (LBP)). Surface electromyography (sEMG) was recorded bilaterally from selected muscle groups for 30 min of cycling for each subject. Statistical tests were performed to determine the difference in fatigue, using mean power frequency difference. LBP group showed a significantly higher fatigue (p<0.05) in left biceps brachii medial when compared to the control group. High fatigue in the back muscles in the LBP group was not found; however, when linear regression was performed for these individuals, the data showed a possibility of worsening in their condition due to 30 min of cycling.

  2. Rechargeable wireless EMG sensor for prosthetic control.

    PubMed

    Lichter, P A; Lange, E H; Riehle, T H; Anderson, S M; Hedin, D S

    2010-01-01

    Surface electrodes in modern myoelectric prosthetics are often embedded in the prosthesis socket and make contact with the skin. These electrodes detect and amplify muscle action potentials from voluntary contractions of the muscle in the residual limb and are used to control the prosthetic's movement and function. There are a number of performance-related deficiencies associated with external electrodes including the maintenance of sufficient electromyogram (EMG) signal amplitude, extraneous noise acquisition, and proper electrode interface maintenance that are expected to be improved or eliminated using the proposed implanted sensors. This research seeks to investigate the design components for replacing external electrodes with fully-implantable myoelectric sensors that include a wireless interface to the prosthetic limbs. This implanted technology will allow prosthetic limb manufacturers to provide products with increased performance, capability, and patient-comfort. The EMG signals from the intramuscular recording electrode are amplified and wirelessly transmitted to a receiver in the prosthetic limb. Power to the implant is maintained using a rechargeable battery and an inductive energy transfer link from the prosthetic. A full experimental system was developed to demonstrate that a wireless biopotential sensor can be designed that meets the requirements of size, power, and performance for implantation.

  3. Muscle fatigue evaluation of astronaut upper limb based on sEMG and subjective assessment

    NASA Astrophysics Data System (ADS)

    Zu, Xiaoqi; Zhou, Qianxiang; Li, Yun

    2012-07-01

    All movements are driven by muscle contraction, and it is easy to cause muscle fatigue. Evaluation of muscle fatigue is a hot topic in the area of astronaut life support training and rehabilitation. If muscle gets into fatigue condition, it may reduce work efficiency and has an impact on psychological performance. Therefore it is necessary to develop an accurate and usable method on muscle fatigue evaluation of astronaut upper limb. In this study, we developed a method based on surface electromyography (sEMG) and subjective assessment (Borg scale) to evaluate local muscle fatigue. Fifteen healthy young male subjects participated in the experiment. They performed isometric muscle contractions of the upper limb. sEMG of the biceps brachii were recorded during the entire process of isotonic muscle contraction and Borg scales of muscle fatigue were collected in certain times. sEMG were divided into several parts, and then mean energy of each parts were calculated by the one-twelfth band octave method. Equations were derived based on the relationship between the mean energy of sEMG and Borg scale. The results showed that cubic curve could describe the degree of local muscle fatigue, and could be used to evaluate and monitor local muscle fatigue during the entire process.

  4. EMG responses in leg muscles to postural perturbations in Huntington's disease.

    PubMed Central

    Huttunen, J; Hömberg, V

    1990-01-01

    This paper compares leg muscle electromyogram (EMG) responses to sudden toe-up tilts of a moveable platform in patients with Huntington's disease (HD), clinically normal offspring at risk of developing HD (HD risks) and healthy controls. The EMG pattern in standing subjects and patients consisted of short- and middle-latency responses (SL and ML) in the stretched triceps surae muscles and long-latency responses (LL) in the shortened tibialis anterior muscles. The SL response could be further divided into two distinct subcomponents termed SL1 and SL2. An ML response was identified in only 50% of normal subjects and patients. HD patients differed from normal subjects by showing delayed onset latencies and prolonged durations for the LL response, and smaller amplitudes for the ML response. The subjects at risk also showed diminished ML amplitudes and prolonged LL durations, but normal LL onset latencies. In the sitting condition, the EMG responses of the HD patients and of the HD risks did not differ from those of controls: in all groups SL1 was reduced and delayed, SL2 slightly enhanced, while ML and LL were absent. Because both afferent and efferent conduction times are normal in HD, the delayed LL onset reflects abnormal supraspinal organisation of postural control in HD, and indicates that basal ganglia may have a modulatory effect on the LL responses. The normal EMG responses in the sitting patients suggest appropriate regulation of these responses according to postural set in HD. PMID:2154557

  5. Muscle fluid shift does not alter EMG global variables during sustained isometric actions.

    PubMed

    von Walden, Ferdinand; Pozzo, Marco; Elman, Ted; Tesch, Per A

    2008-10-01

    Body fluid redistribution occurs in astronauts traveling in space, potentially altering interstitial water content and hence impedance. This in turn may impact the features of electromyographic (EMG) signals measured to compare in-flight muscle function with pre- and post-flight conditions. Thus, the current study aimed at investigating the influence of similar fluid shifts on EMG spectral variables during muscle contractile activity. Ten men performed sustained isometric actions (120 s) at 20% and 60% of maximum voluntary contraction (MVC) following 1-h rest in the vertical or supine position. From single differential EMG signals, recorded from the soleus (SOL), the medial (MG) and lateral (LG) gastrocnemius muscles, initial value and rate of change over time (slope) of mean power frequency (MNF) and average rectified value (ARV) were assessed. MNF initial value showed dependence on muscle (P<0.01), but was unaffected by body tilt. MNF rate of change increased (P<0.001) with increased force and differed across muscles (P<0.05), but was not influenced (P=0.85) by altered body position. Thus, fluid shift resulting from vertical to supine tilt had no impact on myoelectrical manifestations of muscle fatigue. Furthermore, since such alteration of body fluid distribution resembles that occurring in microgravity, our findings suggest this may not be a methodological limitation, when comparing EMG fatigue indices on Earth versus in space.

  6. Automatic identification and classification of muscle spasms in long-term EMG recordings.

    PubMed

    Winslow, Jeffrey; Martinez, Adriana; Thomas, Christine K

    2015-03-01

    Spinal cord injured (SCI) individuals may be afflicted by spasticity, a condition in which involuntary muscle spasms are common. EMG recordings can be analyzed to quantify this symptom of spasticity but manual identification and classification of spasms are time consuming. Here, an algorithm was created to find and classify spasm events automatically within 24-h recordings of EMG. The algorithm used expert rules and time-frequency techniques to classify spasm events as tonic, unit, or clonus spasms. A companion graphical user interface (GUI) program was also built to verify and correct the results of the automatic algorithm or manually defined events. Eight channel EMG recordings were made from seven different SCI subjects. The algorithm was able to correctly identify an average (±SD) of 94.5 ± 3.6% spasm events and correctly classify 91.6 ± 1.9% of spasm events, with an accuracy of 61.7 ± 16.2%. The accuracy improved to 85.5 ± 5.9% and the false positive rate decreased to 7.1 ± 7.3%, respectively, if noise events between spasms were removed. On average, the algorithm was more than 11 times faster than manual analysis. Use of both the algorithm and the GUI program provide a powerful tool for characterizing muscle spasms in 24-h EMG recordings, information which is important for clinical management of spasticity.

  7. Modulation of eyeblink and postauricular reflexes during the anticipation and viewing of food images.

    PubMed

    Hebert, Karen R; Valle-Inclán, Fernando; Hackley, Steven A

    2015-04-01

    One of the goals of neuroscience research on the reward system is to fractionate its functions into meaningful subcomponents. To this end, the present study examined emotional modulation of the eyeblink and postauricular components of startle in 60 young adults during anticipation and viewing of food images. Appetitive and disgusting photos served as rewards and punishments in a guessing game. Reflexes evoked during anticipation were not influenced by valence, consistent with the prevailing view that startle modulation indexes hedonic impact (liking) rather than incentive salience (wanting). During the slide-viewing period, postauricular reflexes were larger for correct than incorrect feedback, whereas the reverse was true for blink reflexes. Probes were delivered in brief trains, but only the first response exhibited this pattern. The specificity of affective startle modification makes it a valuable tool for studying the reward system.

  8. COMMUNALITIES AND DIFFERENCES IN FEAR POTENTIATION BETWEEN CARDIAC DEFENSE AND EYE-BLINK STARTLE

    PubMed Central

    Sánchez, María B.; Guerra, Pedro; Muñoz, Miguel A.; Mata, José Luís; Bradley, Margaret M.; Lang, Peter J.; Vila, Jaime

    2009-01-01

    This study examines similarities and differences in fear potentiation between two protective reflexes: cardiac defense and eye-blink startle. Women reporting intense fear of animals but low fear of blood or intense fear of blood but low fear of animals viewed pictures depicting blood or the feared animal for 6 s in 2 separate trials in counterbalanced order. An intense burst of white noise, able to elicit both a cardiac defense response and a reflexive startle blink, was presented 3.5 s after picture onset. Both cardiac and blink responses were potentiated when highly fearful individuals viewed fearful pictures. However, differences appeared concerning picture order. This pattern of results indicates communalities and differences among protective reflexes that are relevant for understanding the dynamics of emotional reflex modulation. PMID:19572906

  9. Communalities and differences in fear potentiation between cardiac defense and eyeblink startle.

    PubMed

    Sánchez, María B; Guerra, Pedro; Muñoz, Miguel A; Mata, José Luís; Bradley, Margaret M; Lang, Peter J; Vila, Jaime

    2009-11-01

    This study examines similarities and differences in fear potentiation between two protective reflexes: cardiac defense and eyeblink startle. Women reporting intense fear of animals but low fear of blood or intense fear of blood but low fear of animals viewed pictures depicting blood or the feared animal for 6 s in 2 separate trials in counterbalanced order. An intense burst of white noise, able to elicit both a cardiac defense response and a reflexive startle blink, was presented 3.5 s after picture onset. Both cardiac and blink responses were potentiated when highly fearful individuals viewed fearful pictures. However, differences appeared concerning picture order. This pattern of results indicates communalities and differences among protective reflexes that are relevant for understanding the dynamics of emotional reflex modulation.

  10. The time course of face processing: startle eyeblink response modulation by face gender and expression.

    PubMed

    Duval, Elizabeth R; Lovelace, Christopher T; Aarant, Justin; Filion, Diane L

    2013-12-01

    The purpose of this study was to investigate the effects of both facial expression and face gender on startle eyeblink response patterns at varying lead intervals (300, 800, and 3500ms) indicative of attentional and emotional processes. We aimed to determine whether responses to affective faces map onto the Defense Cascade Model (Lang et al., 1997) to better understand the stages of processing during affective face viewing. At 300ms, there was an interaction between face expression and face gender with female happy and neutral faces and male angry faces producing inhibited startle. At 3500ms, there was a trend for facilitated startle during angry compared to neutral faces. These findings suggest that affective expressions are perceived differently in male and female faces, especially at short lead intervals. Future studies investigating face processing should take both face gender and expression into account.

  11. Tourette Syndrome: Complementary Insights from Measures of Cognitive Control, Eyeblink Rate, and Pupil Diameter.

    PubMed

    Tharp, Jordan A; Wendelken, Carter; Mathews, Carol A; Marco, Elysa J; Schreier, Herbert; Bunge, Silvia A

    2015-01-01

    Some individuals with Tourette syndrome (TS) have severe motoric and vocal tics that interfere with all aspects of their lives, while others have mild tics that pose few problems. We hypothesize that observed tic severity reflects a combination of factors, including the degree to which dopaminergic (DA) and/or noradrenergic (NE) neurotransmitter systems have been affected by the disorder, and the degree to which the child can exert cognitive control to suppress unwanted tics. To explore these hypotheses, we collected behavioral and eyetracking data from 26 patients with TS and 26 controls between ages 7 and 14, both at rest and while they performed a test of cognitive control. To our knowledge, this is the first study to use eyetracking measures in patients with TS. We measured spontaneous eyeblink rate as well as pupil diameter, which have been linked, respectively, to DA and NE levels in the central nervous system. Here, we report a number of key findings that held when we restricted analyses to unmedicated patients. First, patients' accuracy on our test of cognitive control accounted for fully 50% of the variance in parentally reported tic severity. Second, patients exhibited elevated spontaneous eyeblink rates compared to controls, both during task performance and at rest, consistent with heightened DA transmission. Third, although neither task-evoked pupil dilation nor resting pupil diameter differed between TS patients and controls, pupil diameter was positively related to parentally reported anxiety levels in patients, suggesting heightened NE transmission in patients with comorbid anxiety. Thus, with the behavioral and eyetracking data gathered from a single task, we can gather objective data that are related both to tic severity and anxiety levels in pediatric patients with TS, and that likely reflect patients' underlying neurochemical disturbances.

  12. Treatment of Handwriting Problems Utilizing EMG Biofeedback Training.

    ERIC Educational Resources Information Center

    Hughes, Howard; And Others

    1979-01-01

    The effects of electromyogram (EMG) biofeedback training on cursive handwriting were investigated with nine fourth graders. A significant reduction in EMG between the first baseline session and last training session was obtained. Four of five characteristics of handwriting improved significantly. (Author/SBH)

  13. Galantamine Facilitates Acquisition of Hippocampus-Dependent Trace Eyeblink Conditioning in Aged Rabbits

    ERIC Educational Resources Information Center

    Weible, Aldis P.; Oh, M. Matthew; Lee, Grace; Disterhoft, John F.

    2004-01-01

    Cholinergic systems are critical to the neural mechanisms mediating learning. Reduced nicotinic cholinergic receptor (nAChR) binding is a hallmark of normal aging. These reductions are markedly more severe in some dementias, such as Alzheimer's disease. Pharmacological central nervous system therapies are a means to ameliorate the cognitive…

  14. Galantamine Facilitates Acquisition of a Trace-Conditioned Eyeblink Response in Healthy, Young Rabbits

    ERIC Educational Resources Information Center

    Simon, Barbara B.; Knuckley, Bryan; Powell, Donald A.

    2004-01-01

    Previous work has demonstrated that drugs increasing brain concentrations of acetylcholine can enhance cognition in aging and brain-damaged organisms. The present study assessed whether galantamine (GAL), an allosteric modulator of nicotinic cholinergic receptors and weak acetylcholinesterase inhibitor, could improve acquisition and retention of…

  15. Galantamine Facilitates Acquisition of Hippocampus-Dependent Trace Eyeblink Conditioning in Aged Rabbits

    ERIC Educational Resources Information Center

    Weible, Aldis P.; Oh, M. Matthew; Lee, Grace; Disterhoft, John F.

    2004-01-01

    Cholinergic systems are critical to the neural mechanisms mediating learning. Reduced nicotinic cholinergic receptor (nAChR) binding is a hallmark of normal aging. These reductions are markedly more severe in some dementias, such as Alzheimer's disease. Pharmacological central nervous system therapies are a means to ameliorate the cognitive…

  16. Galantamine Facilitates Acquisition of a Trace-Conditioned Eyeblink Response in Healthy, Young Rabbits

    ERIC Educational Resources Information Center

    Simon, Barbara B.; Knuckley, Bryan; Powell, Donald A.

    2004-01-01

    Previous work has demonstrated that drugs increasing brain concentrations of acetylcholine can enhance cognition in aging and brain-damaged organisms. The present study assessed whether galantamine (GAL), an allosteric modulator of nicotinic cholinergic receptors and weak acetylcholinesterase inhibitor, could improve acquisition and retention of…

  17. Differential EMG biofeedback for children with ADHD: a control method for neurofeedback training with a case illustration.

    PubMed

    Maurizio, S; Liechti, M D; Brandeis, D; Jäncke, L; Drechsler, R

    2013-06-01

    The objective of the present paper was to develop a differential electromyographic biofeedback (EMG-BF) training for children with attention-deficit/hyperactivity disorder (ADHD) matching multiple neurofeedback training protocols in order to serve as a valid control training. This differential EMG-BF training method feeds back activity from arm muscles involved in fine motor skills such as writing and grip force control. Tonic EMG-BF training (activation and deactivation blocks, involving bimanual motor tasks) matches the training of EEG frequency bands, while phasic EMG-BF training (short activation and deactivation trials) was developed as an equivalent to the training of slow cortical potentials. A case description of a child who learned to improve motor regulation in most task conditions and showed a clinically relevant reduction of behavioral ADHD symptoms illustrates the training course and outcome. Differential EMG-BF training is feasible and provides well-matched control conditions for neurofeedback training in ADHD research. Future studies should investigate its value as a specific intervention for children diagnosed with ADHD and comorbid sensorimotor problems.

  18. Surface EMG power spectrum and intramuscular pH in human vastus lateralis muscle during dynamic exercise.

    PubMed

    Bouissou, P; Estrade, P Y; Goubel, F; Guezennec, C Y; Serrurier, B

    1989-09-01

    The relationship between intramuscular pH and the frequency components of the surface electromyographic (EMG) power spectrum from the vastus lateralis muscle was studied in eight healthy male subjects during brief dynamic exercise. The studies were carried out in placebo control and metabolic alkalosis induced by oral administration of NaHCO3. At the onset of exercise, blood pH was 0.08 units higher in alkalosis compared with placebo. Muscle lactate accumulation during exercise was higher in alkalosis (32 +/- 5 mmol/kg wet wt) than in placebo (17 +/- 4 mmol/kg wet wt), but no difference in intramuscular pH was found between the two conditions. The EMG power spectrum was shifted toward lower frequencies during fatigue in the control condition (10.1 +/- 0.9%), and these spectral shifts, evaluated from changes in the mean power frequency (MPF) of the EMG power spectrum, were further accentuated in alkalosis (19 +/- 2%). Although the changes in frequency components of EMG correlated with muscle lactate accumulation (r = 0.68, P less than 0.01), no direct relationship with muscle pH was observed. We conclude that alkalosis results in a greater reduction in MPF associated with a higher muscle lactate accumulation. However, the good correlation observed between the two variables is not likely causative, and a dissociation between intramuscular pH and the increase in the low-frequency content of EMG power spectrum appears during muscle fatigue.

  19. Oxycodone and Dexamethasone for pain management after tonsillectomy: A placebo-controlled EMG assessed clinical trial

    PubMed Central

    Vaiman, Michael; Krakovski, Daniel; Haitov, Zoe

    2011-01-01

    Summary Background Surface electromyographic (sEMG) study of post-tonsillectomy swallow-evoked muscular reactions was performed in order to evaluate the efficacy and safety of oxycodone and dexamethasone in pain management after tonsillectomy. Material/Methods 90 randomly chosen operated adults were divided into three groups. Group 1 (n=30) was treated with OxyContin (Oxycodone) injections; Group 2 (n=30) was treated with Dexacort (Dexamethasone), and Group 3 (n=30) was a placebo group. Pain assessment included visual analogue scale (VAS) pain score and the EMG data like the timing, electric amplitude and graphic patterns of muscular activity during deglutition. We investigated masseter, infrahyoid and submental-submandibular muscles. Records from trapezius muscle were used for control. The results were compared with previously established normative database. The patients were tested 24 h after surgery. The sEMG data were compared with VAS pain score with regard to changes in clinical condition of the patients. Results Analgesia with oxycodone smoothed the recorded sEMG swallow peaks and increases time of deglutition. Dexamethasone normalized muscular activity in deglutition in cases with edema as detected by the EMG records. Statistically significant difference in muscle reactions was detected between the two Groups and the placebo group. Conclusions Application of oxycodone significantly reduces the postoperative pain. Application of dexamethasone after tonsillectomy is advisable because of the reduction of postoperative morbidity while the reduction of the postoperative pain is secondary to the reduction of edema. SEMG might be used as an adjunctive measure of pain behavior via assessment of muscular reactions to pain and to analgesia. PMID:21959624

  20. Oxycodone and dexamethasone for pain management after tonsillectomy: a placebo-controlled EMG assessed clinical trial.

    PubMed

    Vaiman, Michael; Krakovski, Daniel; Haitov, Zoe

    2011-10-01

    Surface electromyographic (sEMG) study of post-tonsillectomy swallow-evoked muscular reactions was performed in order to evaluate the efficacy and safety of oxycodone and dexamethasone in pain management after tonsillectomy. 90 randomly chosen operated adults were divided into three groups. Group 1 (n = 30) was treated with OxyContin (Oxycodone) injections; Group 2 (n = 30) was treated with Dexacort (Dexamethasone), and Group 3 (n = 30) was a placebo group. Pain assessment included visual analogue scale (VAS) pain score and the EMG data like the timing, electric amplitude and graphic patterns of muscular activity during deglutition. We investigated masseter, infrahyoid and submental-submandibular muscles. Records from trapezius muscle were used for control. The results were compared with previously established normative database. The patients were tested 24 h after surgery. The sEMG data were compared with VAS pain score with regard to changes in clinical condition of the patients. Analgesia with oxycodone smoothed the recorded sEMG swallow peaks and increases time of deglutition. Dexamethasone normalized muscular activity in deglutition in cases with edema as detected by the EMG records. Statistically significant difference in muscle reactions was detected between the two Groups and the placebo group. Application of oxycodone significantly reduces the postoperative pain. Application of dexamethasone after tonsillectomy is advisable because of the reduction of postoperative morbidity while the reduction of the postoperative pain is secondary to the reduction of edema. SEMG might be used as an adjunctive measure of pain behavior via assessment of muscular reactions to pain and to analgesia.

  1. Supplementing biomechanical modeling with EMG analysis

    NASA Technical Reports Server (NTRS)

    Lewandowski, Beth; Jagodnik, Kathleen; Crentsil, Lawton; Humphreys, Bradley; Funk, Justin; Gallo, Christopher; Thompson, William; DeWitt, John; Perusek, Gail

    2016-01-01

    It is well established that astronauts experience musculoskeletal deconditioning when exposed to microgravity environments for long periods of time. Spaceflight exercise is used to counteract these effects, and the Advanced Resistive Exercise Device (ARED) on the International Space Station (ISS) has been effective in minimizing musculoskeletal losses. However, the exercise devices of the new exploration vehicles will have requirements of limited mass, power and volume. Because of these limitations, there is a concern that the exercise devices will not be as effective as ARED in maintaining astronaut performance. Therefore, biomechanical modeling is being performed to provide insight on whether the small Multi-Purpose Crew Vehicle (MPCV) device, which utilizes a single-strap design, will provide sufficient physiological loading to maintain musculoskeletal performance. Electromyography (EMG) data are used to supplement the biomechanical model results and to explore differences in muscle activation patterns during exercises using different loading configurations.

  2. Effects of anxiety sensitivity and expectations on the modulation of the startle eyeblink response during a caffeine challenge.

    PubMed

    Benke, Christoph; Blumenthal, Terry D; Modeß, Christiane; Hamm, Alfons O; Pané-Farré, Christiane A

    2015-09-01

    The way in which the tendency to fear somatic arousal sensations (anxiety sensitivity), in interaction with the created expectations regarding arousal induction, might affect defensive responding to a symptom provocation challenge is not yet understood. The present study investigated the effect of anxiety sensitivity on autonomic arousal, startle eyeblink responses, and reported arousal and alertness to expected vs. unexpected caffeine consumption. To create a match/mismatch of expected and experienced arousal, high and low anxiety sensitive participants received caffeine vs. no drug either mixed in coffee (expectation of arousal induction) or in bitter lemon soda (no expectation of arousal induction) on four separate occasions. Autonomic arousal (heart rate, skin conductance level), respiration (end-tidal CO2, minute ventilation), defensive reflex responses (startle eyeblink), and reported arousal and alertness were recorded prior to, immediately and 30 min after beverage ingestion. Caffeine increased ventilation, autonomic arousal, and startle response magnitudes. Both groups showed comparable levels of autonomic and respiratory responses. The startle eyeblink responses were decreased when caffeine-induced arousal occurred unexpectedly, e.g., after administering caffeine in bitter lemon. This effect was more accentuated in high anxiety sensitive persons. Moreover, in high anxiety sensitive persons, the expectation of arousal (coffee consumption) led to higher subjective alertness when administering caffeine and increased arousal even if no drug was consumed. Unexpected symptom provocation leads to increased attention allocation toward feared arousal sensations in high anxiety sensitive persons. This finding broadens our understanding of modulatory mechanisms in defensive responding to bodily symptoms.

  3. Analysis of dynamic EMG and acceleration measurements in Parkinson's disease.

    PubMed

    Rissanen, Saara M; Kankaanpaa, Markku; Tarvainen, Mika P; Meigal, Alexander; Nuutinen, Juho; Tarkka, Ina M; Airaksinen, Olavi; Karjalainen, Pasi A

    2008-01-01

    In this paper, we bring out modern methods that are potential in analysing differences in the dynamic surface electromyographic (EMG) and acceleration measurements between patients with Parkinson's disease (PD) and healthy persons. These methods are the correlation dimension of EMG, the recurrence rate of EMG, the power of acceleration and the sample entropy of acceleration. In this study, these methods were used to extract features from surface EMG and acceleration recordings measured during elbow flexion and extension movements. The extracted features were used to form high-dimensional feature vectors and the dimensionality of these vectors was then reduced by using the principal component approach. Finally, the feature vectors were discriminated between subjects by using the principal components. The discrimination power of the presented approach was tested with EMG and acceleration data measured from 46 patients with PD (on-medication) and 59 healthy controls. Discrimination results showed that the present method was able to discriminate dynamic EMG and acceleration recordings between patients with PD and healthy controls. Therefore, dynamic surface EMG and acceleration measurements may have potential in the objective and quantitative assessment and diagnosis of PD.

  4. Electromyography (EMG) signal recognition using combined discrete wavelet transform based adaptive neuro-fuzzy inference systems (ANFIS)

    NASA Astrophysics Data System (ADS)

    Arozi, Moh; Putri, Farika T.; Ariyanto, Mochammad; Khusnul Ari, M.; Munadi, Setiawan, Joga D.

    2017-01-01

    People with disabilities are increasing from year to year either due to congenital factors, sickness, accident factors and war. One form of disability is the case of interruptions of hand function. The condition requires and encourages the search for solutions in the form of creating an artificial hand with the ability as a human hand. The development of science in the field of neuroscience currently allows the use of electromyography (EMG) to control the motion of artificial prosthetic hand into the necessary use of EMG as an input signal to control artificial prosthetic hand. This study is the beginning of a significant research planned in the development of artificial prosthetic hand with EMG signal input. This initial research focused on the study of EMG signal recognition. Preliminary results show that the EMG signal recognition using combined discrete wavelet transform and Adaptive Neuro-Fuzzy Inference System (ANFIS) produces accuracy 98.3 % for training and 98.51% for testing. Thus the results can be used as an input signal for Simulink block diagram of a prosthetic hand that will be developed on next study. The research will proceed with the construction of artificial prosthetic hand along with Simulink program controlling and integrating everything into one system.

  5. Characterizing EMG data using machine-learning tools.

    PubMed

    Yousefi, Jamileh; Hamilton-Wright, Andrew

    2014-08-01

    Effective electromyographic (EMG) signal characterization is critical in the diagnosis of neuromuscular disorders. Machine-learning based pattern classification algorithms are commonly used to produce such characterizations. Several classifiers have been investigated to develop accurate and computationally efficient strategies for EMG signal characterization. This paper provides a critical review of some of the classification methodologies used in EMG characterization, and presents the state-of-the-art accomplishments in this field, emphasizing neuromuscular pathology. The techniques studied are grouped by their methodology, and a summary of the salient findings associated with each method is presented.

  6. A Spiking Neural Network in sEMG Feature Extraction

    PubMed Central

    Lobov, Sergey; Mironov, Vasiliy; Kastalskiy, Innokentiy; Kazantsev, Victor

    2015-01-01

    We have developed a novel algorithm for sEMG feature extraction and classification. It is based on a hybrid network composed of spiking and artificial neurons. The spiking neuron layer with mutual inhibition was assigned as feature extractor. We demonstrate that the classification accuracy of the proposed model could reach high values comparable with existing sEMG interface systems. Moreover, the algorithm sensibility for different sEMG collecting systems characteristics was estimated. Results showed rather equal accuracy, despite a significant sampling rate difference. The proposed algorithm was successfully tested for mobile robot control. PMID:26540060

  7. EMG biofeedback of the abductor pollicis brevis in piano performance.

    PubMed

    Montes, R; Bedmar, M; Sol Martin, M

    1993-06-01

    The aim of the present study was to apply EMG biofeedback as an auxiliary to piano teaching techniques. We studied the changes in integrated electromyographic activity, using the abductor pollicis brevis functioning as an agonist during the teaching of identical selective movements of piano playing in two groups, one with EMG biofeedback and the other following traditional method of instruction. The analysis of variance revealed an increase in the peak amplitude and the relaxation rate values for the biofeedback group. These results have implications for the application of piano playing techniques and reveal EMG biofeedback as an aid in the teaching of thumb attack with the abductor pollicis brevis as agonist.

  8. Adaptive neuron-to-EMG decoder training for FES neuroprostheses

    NASA Astrophysics Data System (ADS)

    Ethier, Christian; Acuna, Daniel; Solla, Sara A.; Miller, Lee E.

    2016-08-01

    Objective. We have previously demonstrated a brain-machine interface neuroprosthetic system that provided continuous control of functional electrical stimulation (FES) and restoration of grasp in a primate model of spinal cord injury (SCI). Predicting intended EMG directly from cortical recordings provides a flexible high-dimensional control signal for FES. However, no peripheral signal such as force or EMG is available for training EMG decoders in paralyzed individuals. Approach. Here we present a method for training an EMG decoder in the absence of muscle activity recordings; the decoder relies on mapping behaviorally relevant cortical activity to the inferred EMG activity underlying an intended action. Monkeys were trained at a 2D isometric wrist force task to control a computer cursor by applying force in the flexion, extension, ulnar, and radial directions and execute a center-out task. We used a generic muscle force-to-endpoint force model based on muscle pulling directions to relate each target force to an optimal EMG pattern that attained the target force while minimizing overall muscle activity. We trained EMG decoders during the target hold periods using a gradient descent algorithm that compared EMG predictions to optimal EMG patterns. Main results. We tested this method both offline and online. We quantified both the accuracy of offline force predictions and the ability of a monkey to use these real-time force predictions for closed-loop cursor control. We compared both offline and online results to those obtained with several other direct force decoders, including an optimal decoder computed from concurrently measured neural and force signals. Significance. This novel approach to training an adaptive EMG decoder could make a brain-control FES neuroprosthesis an effective tool to restore the hand function of paralyzed individuals. Clinical implementation would make use of individualized EMG-to-force models. Broad generalization could be achieved by

  9. Towards optimal multi-channel EMG electrode configurations in muscle force estimation: a high density EMG study.

    PubMed

    Staudenmann, Didier; Kingma, Idsart; Stegeman, Dick F; van Dieën, Jaap H

    2005-02-01

    Surface EMG is an important tool in biomechanics, kinesiology and neurophysiology. In neurophysiology the concept of high-density EMG (HD-EMG), using two dimensional electrode grids, was developed for the measurement of spatiotemporal activation patterns of the underlying muscle and its motor units (MU). The aim of this paper was to determine, with the aid of a HD-EMG grid, the relative importance of a number of electrode sensor configurations for optimizing muscle force estimation. Sensor configurations are distinguished in two categories. The first category concerns dimensions: the size of a single electrode and the inter electrode distance (IED). The second category concerns the sensor's spatial distribution: the total area from which signals are obtained (collection surface) and the number of electrodes per cm(2) (collection density). Eleven subjects performed isometric arm extensions at three elbow angles and three contraction levels. Surface-EMG from the triceps brachii muscle and the external force at the wrist were measured. Compared to a single conventional bipolar electrode pair, the force estimation quality improved by about 30% when using HD-EMG. Among the sensor configurations, the collection surface alone appeared to be responsible for the major part of the EMG based force estimation quality by improving it with 25%.

  10. Influence of Fatigue on Hand Muscle Coordination and EMG-EMG Coherence During Three-Digit Grasping

    PubMed Central

    Danna-Dos Santos, Alessander; Poston, Brach; Jesunathadas, Mark; Bobich, Lisa R.; Hamm, Thomas M.

    2010-01-01

    Fingertip force control requires fine coordination of multiple hand muscles within and across the digits. While the modulation of neural drive to hand muscles as a function of force has been extensively studied, much less is known about the effects of fatigue on the coordination of simultaneously active hand muscles. We asked eight subjects to perform a fatiguing contraction by gripping a manipulandum with thumb, index, and middle fingers while matching an isometric target force (40% maximal voluntary force) for as long as possible. The coordination of 12 hand muscles was quantified as electromyographic (EMG) muscle activation pattern (MAP) vector and EMG-EMG coherence. We hypothesized that muscle fatigue would cause uniform changes in EMG amplitude across all muscles and an increase in EMG-EMG coherence in the higher frequency bands but with an invariant heterogeneous distribution across muscles. Muscle fatigue caused a 12.5% drop in the maximum voluntary contraction force (P < 0.05) at task failure and an increase in the SD of force (P < 0.01). Although EMG amplitude of all muscles increased during the fatiguing contraction (P < 0.001), the MAP vector orientation did not change, indicating that a similar muscle coordination pattern was used throughout the fatiguing contraction. Last, EMG-EMG coherence (0–35 Hz) was significantly greater at the end than at the beginning of the fatiguing contraction (P < 0.01) but was heterogeneously distributed across hand muscles. These findings suggest that similar mechanisms are involved for modulating and sustaining digit forces in nonfatiguing and fatiguing contractions, respectively. PMID:20926609

  11. Influence of fatigue on hand muscle coordination and EMG-EMG coherence during three-digit grasping.

    PubMed

    Danna-Dos Santos, Alessander; Poston, Brach; Jesunathadas, Mark; Bobich, Lisa R; Hamm, Thomas M; Santello, Marco

    2010-12-01

    Fingertip force control requires fine coordination of multiple hand muscles within and across the digits. While the modulation of neural drive to hand muscles as a function of force has been extensively studied, much less is known about the effects of fatigue on the coordination of simultaneously active hand muscles. We asked eight subjects to perform a fatiguing contraction by gripping a manipulandum with thumb, index, and middle fingers while matching an isometric target force (40% maximal voluntary force) for as long as possible. The coordination of 12 hand muscles was quantified as electromyographic (EMG) muscle activation pattern (MAP) vector and EMG-EMG coherence. We hypothesized that muscle fatigue would cause uniform changes in EMG amplitude across all muscles and an increase in EMG-EMG coherence in the higher frequency bands but with an invariant heterogeneous distribution across muscles. Muscle fatigue caused a 12.5% drop in the maximum voluntary contraction force (P < 0.05) at task failure and an increase in the SD of force (P < 0.01). Although EMG amplitude of all muscles increased during the fatiguing contraction (P < 0.001), the MAP vector orientation did not change, indicating that a similar muscle coordination pattern was used throughout the fatiguing contraction. Last, EMG-EMG coherence (0-35 Hz) was significantly greater at the end than at the beginning of the fatiguing contraction (P < 0.01) but was heterogeneously distributed across hand muscles. These findings suggest that similar mechanisms are involved for modulating and sustaining digit forces in nonfatiguing and fatiguing contractions, respectively.

  12. Muscle synergy control model-tuned EMG driven torque estimation system with a musculo-skeletal model.

    PubMed

    Min, Kyuengbo; Shin, Duk; Lee, Jongho; Kakei, Shinji

    2013-01-01

    Muscle activity is the final signal for motion control from the brain. Based on this biological characteristic, Electromyogram (EMG) signals have been applied to various systems that interface human with external environments such as external devices. In order to use EMG signals as input control signal for this kind of system, the current EMG driven torque estimation models generally employ the mathematical model that estimates the nonlinear transformation function between the input signal and the output torque. However, these models need to estimate too many parameters and this process cause its estimation versatility in various conditions to be poor. Moreover, as these models are designed to estimate the joint torque, the input EMG signals are tuned out of consideration for the physiological synergetic contributions of multiple muscles for motion control. To overcome these problems of the current models, we proposed a new tuning model based on the synergy control mechanism between multiple muscles in the cortico-spinal tract. With this synergetic tuning model, the estimated contribution of multiple muscles for the motion control is applied to tune the EMG signals. Thus, this cortico-spinal control mechanism-based process improves the precision of torque estimation. This system is basically a forward dynamics model that transforms EMG signals into the joint torque. It should be emphasized that this forward dynamics model uses a musculo-skeletal model as a constraint. The musculo-skeletal model is designed with precise musculo-skeletal data, such as origins and insertions of individual muscles or maximum muscle force. Compared with the mathematical model, the proposed model can be a versatile model for the torque estimation in the various conditions and estimates the torque with improved accuracy. In this paper, we also show some preliminary experimental results for the discussion about the proposed model.

  13. Identification of contaminant type in surface electromyography (EMG) signals.

    PubMed

    McCool, Paul; Fraser, Graham D; Chan, Adrian D C; Petropoulakis, Lykourgos; Soraghan, John J

    2014-07-01

    The ability to recognize various forms of contaminants in surface electromyography (EMG) signals and to ascertain the overall quality of such signals is important in many EMG-enabled rehabilitation systems. In this paper, new methods for the automatic identification of commonly occurring contaminant types in surface EMG signals are presented. Such methods are advantageous because the contaminant type is typically not known in advance. The presented approach uses support vector machines as the main classification system. Both simulated and real EMG signals are used to assess the performance of the methods. The contaminants considered include: 1) electrocardiogram interference; 2) motion artifact; 3) power line interference; 4) amplifier saturation; and 5) additive white Gaussian noise. Results show that the contaminants can readily be distinguished at lower signal to noise ratios, with a growing degree of confusion at higher signal to noise ratios, where their effects on signal quality are less significant.

  14. Daily behavior identification based on sEMG

    NASA Astrophysics Data System (ADS)

    Wang, Zhongwei; Shi, Yuliang

    2017-08-01

    This paper presents a daily behavior identification algorithm based on sEMG to improve the accuracy of behavior identification. In the preprocessing stage, the original sEMG signal is effectively denoised by the combination of EMD denoising and wavelet denoising. In the feature extraction stage, the characteristics of MAV and AR model are extracted by time-frequency domain to express the behavior patterns. In the behavior classification stage, 8 features from 4 sEMG channels of MAV and AR model are use an input neurons of the BP neural network to improve the accuracy of behavior classification identification. Through the learning of a large number of training samples, the accuracy of the behavioral identification on the test samples comes to 91.02% in the experiment, which indicates that the daily behavior identification based on sEMG is a valuable method.

  15. Homomorphic Deconvolution for MUAP Estimation From Surface EMG Signals.

    PubMed

    Biagetti, Giorgio; Crippa, Paolo; Orcioni, Simone; Turchetti, Claudio

    2017-03-01

    This paper presents a technique for parametric model estimation of the motor unit action potential (MUAP) from the surface electromyography (sEMG) signal by using homomorphic deconvolution. The cepstrum-based deconvolution removes the effect of the stochastic impulse train, which originates the sEMG signal, from the power spectrum of sEMG signal itself. In this way, only information on MUAP shape and amplitude were maintained, and then, used to estimate the parameters of a time-domain model of the MUAP itself. In order to validate the effectiveness of this technique, sEMG signals recorded during several biceps curl exercises have been used for MUAP amplitude and time scale estimation. The parameters so extracted as functions of time were used to evaluate muscle fatigue showing a good agreement with previously published results.

  16. Spherical classification of wavelet transformed EMG intensity patterns.

    PubMed

    von Tscharner, Vinzenz

    2009-10-01

    Electromyograms of different muscles can be submitted to a wavelet-transform and arranged in a Multi-Muscle Pattern (MMP). The MMP represents the intensity of the EMG signals of a number of muscles simultaneously in time/frequency space. As previously shown, the MMPs can be represented by points in an Euclidian vector space that was called pattern space. The variability of the MMPs is represented by the distribution of the scattered points in pattern space. The purpose of this study was to investigate the distribution of the points and use the properties of the distribution to classify MMPs. The first task was to test whether the points representing a group of MMPs were located between the inner and outer boundary of a sphere-like domain in whitened pattern space as theoretically predicted. The mean of these points and thus of the MMPs is represented by a point at the center of the sphere. The hypothesis was that the spheres representing points of the MMPs of barefoot and shod runners were sufficiently separated and distinguishable in pattern space to allow classification of the runners according to their shod condition. The results confirmed the hypothesis and revealed that the recognition rate was over 80%. One can conclude and generalize that the points representing MMPs recorded for a certain condition reside between the inner and outer boundary of the sphere. The classification based on the spherical feature represents a much better discrimination than one based on the distance from the mean.

  17. Temporalis function in anthropoids and strepsirrhines: an EMG study.

    PubMed

    Hylander, William L; Wall, Christine E; Vinyard, Christopher J; Ross, Callum; Ravosa, Mathew R; Williams, Susan H; Johnson, Kirk R

    2005-09-01

    The major purpose of this study is to analyze anterior and posterior temporalis muscle force recruitment and firing patterns in various anthropoid and strepsirrhine primates. There are two specific goals for this project. First, we test the hypothesis that in addition to transversely directed muscle force, the evolution of symphyseal fusion in primates may also be linked to vertically directed balancing-side muscle force during chewing (Hylander et al. [2000] Am. J. Phys. Anthropol. 112:469-492). Second, we test the hypothesis of whether strepsirrhines retain the hypothesized primitive mammalian condition for the firing of the anterior temporalis, whereas anthropoids have the derived condition (Weijs [1994] Biomechanics of Feeding in Vertebrates; Berlin: Springer-Verlag, p. 282-320). Electromyographic (EMG) activities of the left and right anterior and posterior temporalis muscles were recorded and analyzed in baboons, macaques, owl monkeys, thick-tailed galagos, and ring-tailed lemurs. In addition, as we used the working-side superficial masseter as a reference muscle, we also recorded and analyzed EMG activity of the left and right superficial masseter in these primates. The data for the anterior temporalis provided no support for the hypothesis that symphyseal fusion in primates is linked to vertically directed jaw muscle forces during mastication. Thus, symphyseal fusion in primates is most likely mainly linked to the timing and recruitment of transversely directed forces from the balancing-side deep masseter (Hylander et al. [2000] Am. J. Phys. Anthropol. 112:469-492). In addition, our data demonstrate that the firing patterns for the working- and balancing-side anterior temporalis muscles are near identical in both strepsirrhines and anthropoids. Their working- and balancing-side anterior temporalis muscles fire asynchronously and reach peak activity during the power stroke. Similarly, their working- and balancing-side posterior temporalis muscles also fire

  18. Time Course of the Rabbit's Conditioned Nictitating Membrane Movements during Acquisition, Extinction, and Reacquisition

    ERIC Educational Resources Information Center

    Kehoe, E. James; Ludvig, Elliot A.; Sutton, Richard S.

    2014-01-01

    The present experiment tested whether or not the time course of a conditioned eyeblink response, particularly its duration, would expand and contract, as the magnitude of the conditioned response (CR) changed massively during acquisition, extinction, and reacquisition. The CR duration remained largely constant throughout the experiment, while CR…

  19. Time Course of the Rabbit's Conditioned Nictitating Membrane Movements during Acquisition, Extinction, and Reacquisition

    ERIC Educational Resources Information Center

    Kehoe, E. James; Ludvig, Elliot A.; Sutton, Richard S.

    2014-01-01

    The present experiment tested whether or not the time course of a conditioned eyeblink response, particularly its duration, would expand and contract, as the magnitude of the conditioned response (CR) changed massively during acquisition, extinction, and reacquisition. The CR duration remained largely constant throughout the experiment, while CR…

  20. 24 DOF EMG controlled hybrid actuated prosthetic hand.

    PubMed

    Atasoy, A; Kaya, E; Toptas, E; Kuchimov, S; Kaplanoglu, E; Ozkan, M

    2016-08-01

    A complete mechanical design concept of an electromyogram (EMG) controlled hybrid prosthetic hand, with 24 degree of freedom (DOF) anthropomorphic structure is presented. Brushless DC motors along with Shape Memory Alloy (SMA) actuators are used to achieve dexterous functionality. An 8 channel EMG is used for detecting 7 basic hand gestures for control purposes. The prosthetic hand will be integrated with the Neural Network (NNE) based controller in the next phase of the study.

  1. Muscle motion and EMG activity in vibration treatment.

    PubMed

    Fratini, Antonio; La Gatta, Antonio; Bifulco, Paolo; Romano, Maria; Cesarelli, Mario

    2009-11-01

    The aim of this study is to highlight the relationship between muscle motion, generated by whole body vibration, and the correspondent electromyographic (EMG) activity and to suggest a new method to customize the stimulation frequency. Simultaneous recordings of EMG and tri-axial accelerations of quadriceps rectus femoris from fifteen subjects undergoing vibration treatments were collected. Vibrations were delivered via a sinusoidal oscillating platform at different frequencies (10-45 Hz). Muscle motion was estimated by processing the accelerometer data. Large EMG motion artifacts were removed using sharp notch filters centred at the vibration frequency and its superior harmonics. EMG-RMS values were computed and analyzed before and after artifact suppression to assess muscular activity. Muscles acceleration amplitude increased with frequency. Muscle displacements revealed a mechanical resonant-like behaviour of the muscle. Resonance frequencies and dumping factors depended on subject. Moreover, RMS of artifact-free EMG was found well correlated (R(2)=0.82) to the actual muscle displacement, while the maximum of the EMG response was found related to the mechanical resonance frequency of muscle. Results showed that maximum muscular activity was found in correspondence to the mechanical resonance of the muscle itself. Assuming the hypothesis that muscle activation is proportional to muscle displacement, treatment optimization (i.e. to choose the best stimulation frequency) could be obtained by simply monitoring local acceleration (resonance), leading to a more effective muscle stimulation. Motion artifact produced an overestimation of muscle activity, therefore its removal was essential.

  2. Kinematical and EMG-classifications of a fencing attack.

    PubMed

    Frère, J; Göpfert, B; Nüesch, C; Huber, C; Fischer, M; Wirz, D; Friederich, N F

    2011-01-01

    8 expert fencers were studied with a 3-dimensional motion analysis system. Each subject performed 10 flèche attacks toward a standardized target. Surface electromyography signals (EMG) were recorded of the deltoid pars clavicularis, infraspinatus and triceps brachii caput laterale muscles of the weapon arm. The recorded EMGs were averaged using EMG wavelet-transformation software. 4 phases were defined based on the arm kinematics and used to classify fencers into 2 groups. A first group of 4 fencers showed an early maximal elbow extension (Early MEE) whereas the second group presented a late maximal elbow extension (Late MEE). 2 EMG-classifications were based on this kinematical classification, one in the time-domain and the other in the frequency-domain by using the spherical classification. The time-domain EMG-classification showed a significantly ( P=0.03) higher normalized deltoid intensity for the Early MEE group (91 ± 18%) than the Late MEE group (36 ± 13%) in the attack phase. The spherical classification revealed that the activity of all the muscles was significantly classified (recognition rate 75%, P=0.04) between the 2 groups. This study of EMG and kinematics of the weapon upper limb in fencing proposes several classifications, which implies a relationship between kinematic strategies, muscular activations and fencing success.

  3. Analysis of surface EMG signal morphology in Parkinson's disease.

    PubMed

    Rissanen, Saara; Kankaanpää, Markku; Tarvainen, Mika P; Nuutinen, Juho; Tarkka, Ina M; Airaksinen, Olavi; Karjalainen, Pasi A

    2007-12-01

    A novel approach is presented for the analysis of surface electromyogram (EMG) morphology in Parkinson's disease (PD). The method is based on histogram and crossing rate (CR) analysis of the EMG signal. In the method, histograms and CR values are used as high-dimensional feature vectors. The dimensionality of them is then reduced using the Karhunen-Loève transform (KLT). Finally, the discriminant analysis of feature vectors is performed in low-dimensional eigenspace. Histograms and CR values were chosen for analysis, because Parkinsonian EMG signals typically involve patterns of EMG bursts. Traditional methods of EMG amplitude and spectral analysis are not effective in analyzing impulse-like signals. The method, which was tested with EMG signals measured from 25 patients with PD and 22 healthy controls, was promising for discriminating between these two groups of subjects. The ratio of correct discrimination by augmented KLT was 86% for the control group and 72% for the patient group. On the basis of these results, further studies are suggested in order to evaluate the usability of this method in early stage diagnostics of PD.

  4. Effect of experimental jaw-muscle pain on the spatial distribution of surface EMG activity of the human masseter muscle during tooth clenching.

    PubMed

    Castroflorio, T; Falla, D; Wang, K; Svensson, P; Farina, D

    2012-02-01

    This study tested the hypothesis that painful injections of glutamate into the human masseter muscle differentially affect the distribution of the electromyographic (EMG) activity in the masseter muscle at rest and during tooth clenching. Surface EMG signals were recorded bilaterally from the superficial masseter of nine healthy men with a grid of 32 electrodes, before and after intramuscular injection of glutamate or isotonic saline, during rest and isometric contractions at 20%, 40%, 60% and 80% of the maximal voluntary bite force. Intramuscular injection of glutamate evoked moderate pain (0-10 visual analogue scale: 6·4 ± 1·4), with sensory-discriminative characteristics of the perceived pain, evaluated with the use of the McGill Pain Questionnaire (MPQ), similar to those previously reported for patients with temporomandibular disorders. There was no effect of the glutamate injection on EMG amplitude during rest, whereas during tooth clenching, the spatial distribution of the masseter EMG activity on both sides was more uniform in the painful condition compared to the control condition. Moreover, the overall EMG amplitude decreased on both sides during the more forceful tooth clenching following glutamate injection. In conclusion, a unilateral painful stimulation was associated with a bilateral inhibition of the masseter muscles during tooth clenching which resulted in a more uniform distribution of EMG activity. © 2011 Blackwell Publishing Ltd.

  5. Startling Sweet Temptations: Hedonic Chocolate Deprivation Modulates Experience, Eating Behavior, and Eyeblink Startle

    PubMed Central

    Blechert, Jens; Naumann, Eva; Schmitz, Julian; Herbert, Beate M.; Tuschen-Caffier, Brunna

    2014-01-01

    Many individuals restrict their food intake to prevent weight gain. This restriction has both homeostatic and hedonic effects but their relative contribution is currently unclear. To isolate hedonic effects of food restriction, we exposed regular chocolate eaters to one week of chocolate deprivation but otherwise regular eating. Before and after this hedonic deprivation, participants viewed images of chocolate and images of high-calorie but non-chocolate containing foods, while experiential, behavioral and eyeblink startle responses were measured. Compared to satiety, hedonic deprivation triggered increased chocolate wanting, liking, and chocolate consumption but also feelings of frustration and startle potentiation during the intertrial intervals. Deprivation was further characterized by startle inhibition during both chocolate and food images relative to the intertrial intervals. Individuals who responded with frustration to the manipulation and those who scored high on a questionnaire of impulsivity showed more relative startle inhibition. The results reveal the profound effects of hedonic deprivation on experiential, behavioral and attentional/appetitive response systems and underscore the role of individual differences and state variables for startle modulation. Implications for dieting research and practice as well as for eating and weight disorders are discussed. PMID:24416437

  6. Eye-blinks in choice response tasks uncover hidden aspects of information processing

    PubMed Central

    Wascher, Edmund; Heppner, Holger; Möckel, Tina; Kobald, Sven Oliver; Getzmann, Stephan

    2015-01-01

    Spontaneous eye-blinks occur much more often than it would be necessary to maintain the tear film on the eyes. Various factors like cognitive demand, task engagement, or fatigue are influencing spontaneous blink rate. During cognitive information processing there is evidence that blinks occur preferably at moments that can be assigned to input stream segmentation. We investigated blinking behavior in three different visual choice response experiments (Experiment 1: spatial Stimulus-Response correspondence, Experiment 2: Change Detection, Experiment 3: Continuous performance Test - AX version). Blinks during the experimental tasks were suppressed when new information was expected, as well as during cognitive processing until the response was executed. Blinks in go trials occurred within a short and relatively constant interval after manual responses. However, blinks were not a side effect of manual behavior, as they occurred in a similar manner in no-go trials in which no manual response was executed. In these trials, blinks were delayed when a prepared response had to be inhibited, compared to trials in which no response was intended. Additionally, time on task effects for no-go blinks mirrored those obtained in go trials. Thus, blinks seem to provide a reliable measure for cognitive processing beyond (or rather additional to) manual responses. PMID:27152110

  7. Startling sweet temptations: hedonic chocolate deprivation modulates experience, eating behavior, and eyeblink startle.

    PubMed

    Blechert, Jens; Naumann, Eva; Schmitz, Julian; Herbert, Beate M; Tuschen-Caffier, Brunna

    2014-01-01

    Many individuals restrict their food intake to prevent weight gain. This restriction has both homeostatic and hedonic effects but their relative contribution is currently unclear. To isolate hedonic effects of food restriction, we exposed regular chocolate eaters to one week of chocolate deprivation but otherwise regular eating. Before and after this hedonic deprivation, participants viewed images of chocolate and images of high-calorie but non-chocolate containing foods, while experiential, behavioral and eyeblink startle responses were measured. Compared to satiety, hedonic deprivation triggered increased chocolate wanting, liking, and chocolate consumption but also feelings of frustration and startle potentiation during the intertrial intervals. Deprivation was further characterized by startle inhibition during both chocolate and food images relative to the intertrial intervals. Individuals who responded with frustration to the manipulation and those who scored high on a questionnaire of impulsivity showed more relative startle inhibition. The results reveal the profound effects of hedonic deprivation on experiential, behavioral and attentional/appetitive response systems and underscore the role of individual differences and state variables for startle modulation. Implications for dieting research and practice as well as for eating and weight disorders are discussed.

  8. EMG and peak force responses to PNF stretching and the relationship between stretching-induced force deficits and bilateral deficits

    PubMed Central

    Cengiz, Asim

    2015-01-01

    [Purpose] The aim of the present study was to investigate the possibility of an interaction between stretching induced deficit (SFD) and bilateral deficits (BLD) during maximal voluntary isometric hand flexion under PNF stretch and no-stretch conditions through measurement of EMG and force production. [Subjects and Methods] Ten physically active male Caucasian students (age, 24.1±2.38 years; body mass, 79.48±11.40 kg; height, 174.15±0.8 cm) volunteered to participate in this study. EMG and force measurements of the subjects were recorded during either unilateral or bilateral 3-second maximal voluntary isometric hand flexion (MVC) against a force transducer. The paired sample t-test was used to examine the significance of differences among several conditions. Pearson product-moment correlation was used to evaluate the associations between different parameters. [Results] Stretching-induced deficits correlated with bilateral deficits in both force (r=0.85) and iEMG (r=0.89). PNF stretching caused significant decrements in the bilateral and unilateral conditions for both the right and left sides. [Conclusion] Since both force and iEMG decreases were observed in most measurements; it suggests there is a neural mechanism behinnd both the BLD and the SFD. PMID:25931696

  9. Single fiber EMG Fiber density and its relationship to Macro EMG amplitude in reinnervation.

    PubMed

    Sandberg, Arne

    2014-12-01

    The objective was to elucidate the relation between the Macro EMG parameters fiber density (FD) and Macro amplitude in reinnervation in the purpose to use the FD parameter as a surrogate marker for reinnervation instead of the Macro amplitude. Macro EMG with FD was performed in 278 prior polio patients. The Biceps Brachii and the Tibialis anterior muscles were investigated. FD was more sensitive for detection of signs of reinnervation but showed lesser degree of abnormality than the Macro amplitude. FD and Macro MUP amplitude showed a non-linear relation with a great variation in FD for given Macro amplitude level. The relatively smaller increase in FD compared to Macro amplitude in addition to the non-linear relationship between the FD and the Macro amplitude regarding reinnervation in prior polio can be due to technical reasons and muscle fiber hypertrophy. The FD parameter has a relation to Macro MUP amplitude but cannot alone be used as a quantitative marker of the degree of reinnervation.

  10. Re-evaluation of EMG-torque relation in chronic stroke using linear electrode array EMG recordings.

    PubMed

    Bhadane, Minal; Liu, Jie; Rymer, W Zev; Zhou, Ping; Li, Sheng

    2016-06-28

    The objective was to re-evaluate the controversial reports of EMG-torque relation between impaired and non-impaired sides using linear electrode array EMG recordings. Ten subjects with chronic stroke performed a series of submaximal isometric elbow flexion tasks. A 20-channel linear array was used to record surface EMG of the biceps brachii muscles from both impaired and non-impaired sides. M-wave recordings for bilateral biceps brachii muscles were also made. Distribution of the slope of the EMG-torque relations for the individual channels showed a quasi-symmetrical "M" shaped pattern. The lowest value corresponded to the innervation zone (IZ) location. The highest value from the slope curve for each side was selected for comparison to minimize the effect of electrode placement and IZ asymmetry. The slope was greater on the impaired side in 4 of 10 subjects. There were a weak correlation between slope ratio and strength ratio and a moderate to high correlation between slope ratio and M-wave ratio between two sides. These findings suggest that the EMG-torque relations are likely mediated and influenced by multiple factors. Our findings emphasize the importance of electrode placement and suggest the primary role of peripheral adaptive changes in the EMG-torque relations in chronic stroke.

  11. Re-evaluation of EMG-torque relation in chronic stroke using linear electrode array EMG recordings

    PubMed Central

    Bhadane, Minal; Liu, Jie; Rymer, W. Zev; Zhou, Ping; Li, Sheng

    2016-01-01

    The objective was to re-evaluate the controversial reports of EMG-torque relation between impaired and non-impaired sides using linear electrode array EMG recordings. Ten subjects with chronic stroke performed a series of submaximal isometric elbow flexion tasks. A 20-channel linear array was used to record surface EMG of the biceps brachii muscles from both impaired and non-impaired sides. M-wave recordings for bilateral biceps brachii muscles were also made. Distribution of the slope of the EMG-torque relations for the individual channels showed a quasi-symmetrical “M” shaped pattern. The lowest value corresponded to the innervation zone (IZ) location. The highest value from the slope curve for each side was selected for comparison to minimize the effect of electrode placement and IZ asymmetry. The slope was greater on the impaired side in 4 of 10 subjects. There were a weak correlation between slope ratio and strength ratio and a moderate to high correlation between slope ratio and M-wave ratio between two sides. These findings suggest that the EMG-torque relations are likely mediated and influenced by multiple factors. Our findings emphasize the importance of electrode placement and suggest the primary role of peripheral adaptive changes in the EMG-torque relations in chronic stroke. PMID:27349938

  12. Electromyography (EMG) accuracy compared to muscle biopsy in childhood.

    PubMed

    Rabie, Malcolm; Jossiphov, Joseph; Nevo, Yoram

    2007-07-01

    Reports show wide variability of electromyography (EMG) in detecting pediatric neuromuscular disorders. The study's aim was to determine EMG/nerve conduction study accuracy compared to muscle biopsy and final clinical diagnosis, and sensitivity for myopathic motor unit potential detection in childhood. Of 550 EMG/nerve conduction studies performed by the same examiner from a pediatric neuromuscular service, 27 children (ages 6 days to 16 years [10 boys; M:F, 1:1.7]) with muscle biopsies and final clinical diagnoses were compared retrospectively. Final clinical diagnoses were congenital myopathies (5 of 27,18%), nonspecific myopathies (biopsy myopathic, final diagnosis uncertain; 6 of 27, 22%), congenital myasthenic syndrome (3 of 27, 11%), juvenile myasthenia gravis (1 of 27, 4%), arthrogryposis multiplex congenita (2 of 27, 7%), hereditary motor and sensory neuropathy (1 of 27, 4%), bilateral peroneal neuropathies (1 of 27, 4%), and normal (8 of 27, 30%). There were no muscular dystrophy or spinal muscular atrophy patients. EMG/nerve conduction studies had a 74% agreement with final clinical diagnoses and 100% agreement in neurogenic, neuromuscular junction, and normal categories. Muscle biopsies concurred with final diagnoses in 87%, and 100% in myopathic and normal categories. In congenital myasthenic syndrome, muscle biopsies showed mild variation in fiber size in 2 of 3 children and were normal in 1 of 3. EMG sensitivity for detecting myopathic motor unit potentials in myopathies was 4 of 11 (36%), greater over 2 years of age (3 of 4, 75%), compared to infants less than 2 years (1 of 7, 14%), not statistically significant (P = .0879). EMGs false-negative for myopathy in infants < 2 years of age were frequently neurogenic (3 of 6, 50%). In congenital myopathies EMG detected myopathic motor unit potentials in 40%, with false-negative results neurogenic (20%) or normal (40%). Because our study has no additional tests for active myopathies, for example Duchenne

  13. Relationship between EMG signals and force in human vastus lateralis muscle using multiple bipolar wire electrodes.

    PubMed

    Onishi, H; Yagi, R; Akasaka, K; Momose, K; Ihashi, K; Handa, Y

    2000-02-01

    This paper describes the relationship between knee extension force and EMG signals detected by multiple bipolar wire electrodes inserted into the human vastus lateralis muscle under isometric conditions. Six healthy male volunteers participated in this study. Eight pairs of bipolar wire electrodes were inserted into the right vastus lateralis muscle and the EMG data were simultaneously detected and analyzed. The EMG raw data and individual force-IEMG relations were influenced by the location of the electrode inserted into the muscle. The force and IEMG relationship averaged across subjects detected from the eight electrodes, however, showed almost the same linear correlation in spite of different electrode locations. No linear correlation was observed between MdF and the knee extension force. This result suggests that, if all of the muscle fibers participate in the same action at the same time, the averaged normalized IEMG from any places using wire electrodes could reflect the total activities of that muscle even if the muscle is large.

  14. Virtual biomechanics: a new method for online reconstruction of force from EMG recordings.

    PubMed

    de Rugy, Aymar; Loeb, Gerald E; Carroll, Timothy J

    2012-12-01

    Current methods to reconstruct muscle contributions to joint torque usually combine electromyograms (EMGs) with cadaver-based estimates of biomechanics, but both are imperfect representations of reality. Here, we describe a new method that enables online force reconstruction in which we optimize a "virtual" representation of muscle biomechanics. We first obtain tuning curves for the five major wrist muscles from the mean rectified EMG during the hold phase of an isometric aiming task when a cursor is driven by actual force recordings. We then apply a custom, gradient-descent algorithm to determine the set of "virtual pulling vectors" that best reach the target forces when combined with the observed muscle activity. When these pulling vectors are multiplied by the rectified and low-pass-filtered (1.3 Hz) EMG of the five muscles online, the reconstructed force provides a close spatiotemporal match to the true force exerted at the wrist. In three separate experiments, we demonstrate that the technique works equally well for surface and fine-wire recordings and is sensitive to biomechanical changes elicited by a modification of the forearm posture. In all conditions tested, muscle tuning curves obtained when the task was performed with feedback of reconstructed force were similar to those obtained when the task was performed with real force feedback. This online force reconstruction technique provides new avenues to study the relationship between neural control and limb biomechanics since the "virtual biomechanics" can be systematically altered at will.

  15. Facial EMG responses to odors in solitude and with an audience.

    PubMed

    Jäncke, L; Kaufmann, N

    1994-04-01

    Two experiments were undertaken to examine whether facial responses to odors correlate with the hedonic odor evaluation. Experiment 1 examined whether subjects (n = 20) spontaneously generated facial movements associated with odor evaluation when they are tested in private. To measure facial responses, EMG was recorded over six muscle regions (M. corrugator supercilii, M. procerus, M. nasalis, M. levator, M. orbicularis oculi and M. zygomaticus major) using surface electrodes. In experiment 2 the experimental group (n = 10) smelled the odors while they were visually inspected by the experimenter sitting in front of the test subjects. The control group (n = 10) performed the same experimental condition as those subjects participating in experiment 1. Facial EMG over four mimetic muscle regions (M. nasalis, M. levator, M. zygomaticus major, M. orbicularis oculi) was measured while subjects smelled different odors. The main findings of this study may be summarized as follows: (i) there was no correlation between valence rating and facial EMG responses; (ii) pleasant odors did not evoke smiles when subjects smelled the odors in private; (iii) in solitude, highly concentrated malodors evoked facial EMG reactions of those mimetic muscles which are mainly involved in generating a facial display of disgust; (iv) those subjects confronted with an audience showed stronger facial reactions over the periocular and cheek region (indicative of a smile) during the smelling of pleasant odors than those who smelled these odors in private; (v) those subjects confronted with an audience showed stronger facial reactions over the M. nasalis region (indicative of a display of disgust) during the smelling of malodors than those who smelled the malodors in private. These results were taken as evidence for a more social communicative function of facial displays and strongly mitigates the reflexive-hedonic interpretation of facial displays to odors as supposed by Steiner.

  16. Reflex-mediated dynamic neuromuscular stabilization in stroke patients: EMG processing and ultrasound imaging.

    PubMed

    Yoon, Hyun S; You, Joshua Sung H

    2017-07-20

    Postural core instability is associated with poor dynamic balance and a high risk of serious falls. Both neurodevelopmental treatment (NDT) and dynamic neuromuscular stabilization (DNS) core stabilization exercises have been used to improve core stability, but the outcomes of these treatments remain unclear. This study was undertaken to examine the therapeutic effects of NDT and DNS core stabilization exercises on muscular activity, core stability, and core muscle thickness. Ten participants (5 healthy adults; 5 hemiparetic stroke patients) were recruited. Surface electromyography (EMG) was used to determine core muscle activity of the transversus abdominis/internal oblique (TrA/IO), external oblique (EO), and rectus abdominis (RA) muscles. Ultrasound imaging was used to measure transversus abdominals/internal oblique (TrA/IO) thickness, and a pressure biofeedback unit (PBU) was used to measure core stability during the DNS and NDT core exercise conditions. Data are reported as median and range and were compared using nonparametric Mann - Whitney U test and Wilcoxon signed rank test at p< 0.05. Both healthy and hemiparetic stroke groups showed greater median EMG amplitude in the TrA/IO muscles, core stability, and muscle thickness values during the DNS exercise condition than during the NDT core exercise condition, respectively (p< 0.05). However, the relative changes in the EMG amplitude, core stability, and muscle thickness values were greater during the DNS exercise condition than during the NDT core exercise condition in the hemiparetic stroke patient group (p< 0.05). Our novel results provide the first clinical evidence that DNS is more effective than NDT in both healthy and hemiparetic stroke subjects to provide superior deep core muscle activation, core stabilization, and muscle thickness. Moreover, such advantageous therapeutic benefits of the DNS core stabilization exercise over the NDT exercise were more apparent in the hemiparetis stroke patients than

  17. Reliability of surface EMG during sustained contractions of the quadriceps.

    PubMed

    Mathur, S; Eng, J J; MacIntyre, D L

    2005-02-01

    The purpose of this study was to determine test-retest reliability for median frequency (MDF) and amplitude of surface EMG during sustained fatiguing contractions of the quadriceps. Twenty-two healthy subjects (11 males and 11 females) were tested on two days held one week apart. Surface EMG was recorded from rectus femoris (RF), vastus lateralis (VL) and vastus medialis (VM) during sustained isometric contractions at 80% and 20% of maximal voluntary contraction (MVC) held to exhaustion. Quadriceps fatigue was described using four measures for both MDF and amplitude of EMG: initial, final, normalized final and slope. For both MDF and amplitude, the initial, final and normalized EMG showed moderate to high reliability for all three muscle groups at both contraction levels (ICC=0.59-0.88 for MDF; ICC=0.58-0.99 for amplitude). Slope of MDF and amplitude was associated with a large degree of variability and low ICCs for the 80% but not the 20% MVC. MDF and amplitude of EMG during sustained contractions of the quadriceps are reproducible; normalized final values of MDF and amplitude show better reliability than slope.

  18. Simultaneous EEG and EMG biofeedback for peak performance in musicians.

    PubMed

    Markovska-Simoska, Silvana; Pop-Jordanova, Nada; Georgiev, Dejan

    2008-07-01

    The aim of this study was to determine the effects of alpha neurofeedback and EMG biofeedback protocols for improvement of musical performance in violinists. The sample consisted of 12 music students (10 violinists and 2 viola players) from the Faculty of Music, Skopje (3 males, mean age of 20 +/- 0 and 9 females, mean age = 20.89 +/- 2.98). Six of them had a low alpha peak frequency (APF) (< 10 Hz), and six a high APF (> 10 Hz). The sample was randomized in two groups. The students from the experimental group participated in 20 sessions of biofeedback (alpha/EMG), combined with music practice, while the students from the control group did only music practice. Average absolute power, interhemispheric coherence in the alpha band, alpha peak frequency (APF), individual alpha band width (IABW), amount of alpha suppression (AAS) and surface forehead integrated EMG power (IEMG), as well as a score on musical performance and inventories measuring anxiety, were assessed. Alpha-EEG/EMG-biofeedback was associated with a significant increase in average alpha power, APF and IABW in all the participants and with decreases in IEMG only in high-APF musicians. The biofeedback training success was positively correlated with the alpha power, IcoH, APF, IABW and baseline level of APF and IABW. Alpha-EEG/EMG biofeedback is capable of increasing voluntary self-regulation and the quality of musical performance. The efficiency of biofeedback training depends on the baseline EEG alpha activity status, in particular the APF.

  19. Excitatory Cerebellar Nucleocortical Circuit Provides Internal Amplification during Associative Conditioning

    PubMed Central

    Gao, Zhenyu; Proietti-Onori, Martina; Lin, Zhanmin; ten Brinke, Michiel M.; Boele, Henk-Jan; Potters, Jan-Willem; Ruigrok, Tom J.H.; Hoebeek, Freek E.; De Zeeuw, Chris I.

    2016-01-01

    Summary Closed-loop circuitries between cortical and subcortical regions can facilitate precision of output patterns, but the role of such networks in the cerebellum remains to be elucidated. Here, we characterize the role of internal feedback from the cerebellar nuclei to the cerebellar cortex in classical eyeblink conditioning. We find that excitatory output neurons in the interposed nucleus provide efference-copy signals via mossy fibers to the cerebellar cortical zones that belong to the same module, triggering monosynaptic responses in granule and Golgi cells and indirectly inhibiting Purkinje cells. Upon conditioning, the local density of nucleocortical mossy fiber terminals significantly increases. Optogenetic activation and inhibition of nucleocortical fibers in conditioned animals increases and decreases the amplitude of learned eyeblink responses, respectively. Our data show that the excitatory nucleocortical closed-loop circuitry of the cerebellum relays a corollary discharge of premotor signals and suggests an amplifying role of this circuitry in controlling associative motor learning. PMID:26844836

  20. Purkinje cell activity during classical conditioning with different conditional stimuli explains central tenet of Rescorla–Wagner model

    PubMed Central

    Rasmussen, Anders; Zucca, Riccardo; Johansson, Fredrik; Jirenhed, Dan-Anders; Hesslow, Germund

    2015-01-01

    A central tenet of Rescorla and Wagner’s model of associative learning is that the reinforcement value of a paired trial diminishes as the associative strength between the presented stimuli increases. Despite its fundamental importance to behavioral sciences, the neural mechanisms underlying the model have not been fully explored. Here, we present findings that, taken together, can explain why a stronger association leads to a reduced reinforcement value, within the context of eyeblink conditioning. Specifically, we show that learned pause responses in Purkinje cells, which trigger adaptively timed conditioned eyeblinks, suppress the unconditional stimulus (US) signal in a graded manner. Furthermore, by examining how Purkinje cells respond to two distinct conditional stimuli and to a compound stimulus, we provide evidence that could potentially help explain the somewhat counterintuitive overexpectation phenomenon, which was derived from the Rescorla–Wagner model. PMID:26504227

  1. Individual Differences in Cognitive-Flexibility: The Influence of Spontaneous Eyeblink Rate, Trait Psychoticism and Working Memory on Attentional Set-Shifting

    ERIC Educational Resources Information Center

    Tharp, Ian J.; Pickering, Alan D.

    2011-01-01

    Individual differences in psychophysiological function have been shown to influence the balance between flexibility and distractibility during attentional set-shifting [e.g., Dreisbach et al. (2005). Dopamine and cognitive control: The influence of spontaneous eyeblink rate and dopamine gene polymorphisms on perseveration and distractibility.…

  2. Frontal midline theta rhythm and eyeblinking activity during a VDT task and a video game: useful tools for psychophysiology in ergonomics.

    PubMed

    Yamada, F

    1998-05-01

    The necessity of psychophysiological research in ergonomics has gradually been recognized in Japan. In this paper, frontal midline theta rhythm (Fm-theta) and eyeblinking are recommended as tools in this field, especially for assessing workers' attention concentration, mental workload, fatigue, and interest during VDT work at the workplace and playing video games at home. In experiment 1, Fm-theta and eyeblink rates were measured in 10 Japanese abacus experts (Group E) and 10 normal students (Group C) during a visual search task with VDT. Memory load affected all measures. The amount of Fm-theta appeared more in Group E than Group C, but blink rate was lower in Group E than in Group C. As abacus experts have such highly developed skills in concentration, the result indicates that the amount of Fm-theta would be a good index of attention concentration in VDT workers. The second experiment was done with 10 school-aged children as subjects during three visual tasks: video game, mental test and animation. Amounts of Fm-theta and the degree of blink inhibition were maximum while playing the video game, which all subjects reported they most preferred, and minimum while watching animation, which eight subjects reported to be most boring. An interesting task would seem to provoke Fm-theta and inhibit eyeblink activity. From these two experiments, Fm-theta and eyeblink rate would appear to be good indices of attention concentration and task pleasantness of a mental task using VDT.

  3. Individual Differences in Cognitive-Flexibility: The Influence of Spontaneous Eyeblink Rate, Trait Psychoticism and Working Memory on Attentional Set-Shifting

    ERIC Educational Resources Information Center

    Tharp, Ian J.; Pickering, Alan D.

    2011-01-01

    Individual differences in psychophysiological function have been shown to influence the balance between flexibility and distractibility during attentional set-shifting [e.g., Dreisbach et al. (2005). Dopamine and cognitive control: The influence of spontaneous eyeblink rate and dopamine gene polymorphisms on perseveration and distractibility.…

  4. Archery performance level and repeatability of event-related EMG.

    PubMed

    Soylu, A R; Ertan, H; Korkusuz, F

    2006-12-01

    The purpose of the current study was to compare the repeatability of electromyographic linear envelopes (LE) of archery groups. Surface electromyography (EMG) signals of musculus flexor digitorum superficialis (MFDS) and extensor digitorum (MED) of 23 participants (seven skilled, six beginner archers and ten non-archers) were recorded during archery shooting. Two-second periods (clicker falls at first second) of 12 shots' EMG data were recorded, full-wave rectified and filtered (60 ms moving-average filter) for each participant's drawing arm. Repeatability was investigated by using a statistical criterion, variance ratio (VR). Archers' performances were evaluated in terms of FITA scores. The results showed that FITA scores were significantly correlated to the VRs of MFDS and MED. EMG LEs were more repeatable among archers than non-archers. Therefore, we inferred that VRs of MFDS and MED might be important variables for (a) assessing shooting techniques, (b) evaluation of archers' progress, and (c) selection of talented archers.

  5. Emg Signal Analysis of Healthy and Neuropathic Individuals

    NASA Astrophysics Data System (ADS)

    Gupta, Ashutosh; Sayed, Tabassum; Garg, Ridhi; Shreyam, Richa

    2017-08-01

    Electromyography is a method to evaluate levels of muscle activity. When a muscle contracts, an action potential is generated and this circulates along the muscular fibers. In electromyography, electrodes are connected to the skin and the electrical activity of muscles is measured and graph is plotted. The surface EMG signals picked up during the muscular activity are interfaced with a system. The EMG signals from individual suffering from Neuropathy and healthy individual, so obtained, are processed and analyzed using signal processing techniques. This project includes the investigation and interpretation of EMG signals of healthy and Neuropathic individuals using MATLAB. The prospective use of this study is in developing the prosthetic device for the people with Neuropathic disability.

  6. Driving Electric Vehicle by EMG Signal Considering Frequency Components

    NASA Astrophysics Data System (ADS)

    Aso, Shinichi; Sasaki, Akinori; Hashimoto, Hiroshi; Ishii, Chiharu

    This paper proposes a useful method driving the electric vehicle by EMG signals (Electromyographic signals) which are filtered on the basis of frequency components which change with muscle contraction. This method estimates strength of muscular tension by a single EMG signal. By our method, user is able to control speed of the electric vehicle by strength of muscular tension. The method of speed control may give user good or bad operation feeling in the meaning of SD (Semantic Differential) method and factor analysis. The operation feeling is evaluated by experiment on EMG interface in cases of using filters or not. As a result, it is shown that operation feeling is influenced by this method.

  7. Eyelid contour detection and tracking for startle research related eye-blink measurements from high-speed video records.

    PubMed

    Bernard, Florian; Deuter, Christian Eric; Gemmar, Peter; Schachinger, Hartmut

    2013-10-01

    Using the positions of the eyelids is an effective and contact-free way for the measurement of startle induced eye-blinks, which plays an important role in human psychophysiological research. To the best of our knowledge, no methods for an efficient detection and tracking of the exact eyelid contours in image sequences captured at high-speed exist that are conveniently usable by psychophysiological researchers. In this publication a semi-automatic model-based eyelid contour detection and tracking algorithm for the analysis of high-speed video recordings from an eye tracker is presented. As a large number of images have been acquired prior to method development it was important that our technique is able to deal with images that are recorded without any special parametrisation of the eye tracker. The method entails pupil detection, specular reflection removal and makes use of dynamic model adaption. In a proof-of-concept study we could achieve a correct detection rate of 90.6%. With this approach, we provide a feasible method to accurately assess eye-blinks from high-speed video recordings.

  8. Voluntary EMG-to-force estimation with a multi-scale physiological muscle model.

    PubMed

    Hayashibe, Mitsuhiro; Guiraud, David

    2013-09-04

    novel approach that allows EMG-force estimation based on a multi-scale physiology model integrating Hill approach for the passive elements and microscopic cross-bridge representations for the contractile element. The experimental evaluation highlights estimation improvements especially a larger range of contraction conditions with integration of the neural activation frequency property and force-velocity relationship through cross-bridge dynamics consideration.

  9. Computer algorithms to characterize individual subject EMG profiles during gait.

    PubMed

    Bogey, R A; Barnes, L A; Perry, J

    1992-09-01

    Three methods of precisely determining onset and cessation times of gait EMG were investigated. Subjects were 24 normal adults and 32 individuals with gait pathologies. Soleus muscle EMG during free speed level walking was obtained with fine wires, and was normalized by manual muscle test (%MMT). Linear envelopes were generated from the rectified, integrated EMG at each percent gait cycle (%GC) of each stride in individual gait trials. Three methods were used to generate EMG profiles for each tested subject. The ensemble average (EAV) was determined for each subject from the mean relative intensity of the linear envelopes. Low relative intensity or short duration EMG was removed from the ensemble average to create the intensity filtered average (IFA). The packet analysis method (PAC) created an EMG profile from the linear envelopes in successive strides whose respective centroid %GC locations were within +/- 15%GC of each other. Control values for onset and cessation times of individual gait trials were calculated after spurious outliers were removed. Mean onset and cessation times across subjects for control values and the experimental methods (EAV, IFA, and PAC) were calculated. Dunnett's test (p less than .05) was performed to compare control and experimental groups in patient and normal trials. EAV differed from control values for onsets (p less than .01), cessations (p less than .01), and durations (p less than .01) in both normal and patient trials. IFA and PAC had no significant differences from control value means. IFA was selected for clinical use as automatic analysis could be performed on all trials and a minimum number of decision rules were needed.

  10. EMG and MMG activities of agonist and antagonist muscles in Parkinson's disease patients during absolute submaximal load holding.

    PubMed

    Marusiak, Jaroslaw; Jaskólska, Anna; Kisiel-Sajewicz, Katarzyna; Yue, Guang H; Jaskólski, Artur

    2009-10-01

    The purpose of the study was (1) to assess changes in electromyographical (EMG) and mechanomyographical (MMG) signals of the biceps and triceps brachii muscles during absolute submaximal load holding in Parkinson's disease patients tested during their medication "ON-phase" and in age-matched controls, and (2) to check whether mechanomyography can be useful in evaluation of neuromuscular system activity in Parkinson's disease patients. The data analysis was performed on nine females with Parkinson's disease and six healthy, age-matched females. The EMG and MMG signals were recorded from the short head of the biceps brachii (BB) and the lateral head of the triceps brachii (TB) muscles. It was concluded that compared to the controls, the Parkinson's disease patients exhibited higher amplitude in the biceps brachii muscle and lower median frequency of the MMG signal in the both tested muscles. However, no differences in the EMG amplitude and an increase of the EMG median frequency in the triceps brachii muscle of the Parkinson's disease group were observed. The MMG was not affected by physiological postural tremor and can depict differences between parkinsonians and controls, which may suggest that it is valuable tool for neuromuscular assessment for this condition.

  11. Characterization of surface EMG signals using improved approximate entropy*

    PubMed Central

    Chen, Wei-ting; Wang, Zhi-zhong; Ren, Xiao-mei

    2006-01-01

    An improved approximate entropy (ApEn) is presented and applied to characterize surface electromyography (sEMG) signals. In most previous experiments using nonlinear dynamic analysis, this certain processing was often confronted with the problem of insufficient data points and noisy circumstances, which led to unsatisfactory results. Compared with fractal dimension as well as the standard ApEn, the improved ApEn can extract information underlying sEMG signals more efficiently and accurately. The method introduced here can also be applied to other medium-sized and noisy physiological signals. PMID:16972328

  12. Visual and graviceptive influences on lower leg EMG activity in humans during brief falls.

    PubMed

    Wicke, R W; Oman, C M

    1982-01-01

    Human subjects were suspended in a safety harness 28 cm above the floor by a steel cable connected to a computer controlled force generator (electromagnetic brake). After the subjects were unexpectedly released, various controlled patterns of downward acceleration (less than 1 g) could be produced. During the falls, EMG activity was recorded simultaneously from the gastrocnemius, soleus, tibialis anterior, rectus femoris, and biceps femoris, along with knee and ankle joint angle in one leg. Subjects were tested eyes closed and also eyes open, both in darkness and in light using a wide field visual display. The display scene could be moved downwards at exactly the same velocity as the moving subject, left fixed with respect to the laboratory ("normal" visual field), or moved upwards at a speed equal to the subject's falling speed (upward moving visual field). Ten vestibularly normal subjects each underwent a total of 45 drops, experiencing three replications of each vision/motion combination used. Under normal visual field conditions, both short and long latency postural responses were seen, which were dependent on the magnitude of the acceleration stimulus. Several of the visual conditions significantly altered both the short and the long latency responses in most of the muscles tested. Effects were particularly prominent in the gastrocnemius and soleus, and were also more pronounced during slow (0.5 g) falls. The upward moving visual field condition increased the short latency EMG reaction in gastrocnemius and soleus for 0.5 g falls. A preliminary scheme for visual-vestibular interaction in short latency EMG responses is presented. Long latency responses are more variable and not conducive to a simple interpretation.

  13. Storage of a naturally acquired conditioned response is impaired in patients with cerebellar degeneration.

    PubMed

    Thieme, Andreas; Thürling, Markus; Galuba, Julia; Burciu, Roxana G; Göricke, Sophia; Beck, Andreas; Aurich, Volker; Wondzinski, Elke; Siebler, Mario; Gerwig, Marcus; Bracha, Vlastislav; Timmann, Dagmar

    2013-07-01

    Previous findings suggested that the human cerebellum is involved in the acquisition but not the long-term storage of motor associations. The finding of preserved retention in cerebellar patients was fundamentally different from animal studies which show that both acquisition and retention depends on the integrity of the cerebellum. The present study investigated whether retention had been preserved because critical regions of the cerebellum were spared. Visual threat eye-blink responses, that is, the anticipatory closure of the eyes to visual threats, have previously been found to be naturally acquired conditioned responses. Because acquisition is known to take place in very early childhood, visual threat eye-blink responses can be used to test retention in patients with adult onset cerebellar disease. Visual threat eye-blink responses were tested in 19 adult patients with cerebellar degeneration, 27 adult patients with focal cerebellar lesions due to stroke, 24 age-matched control subjects, and 31 younger control subjects. High-resolution structural magnetic resonance images were acquired in patients to perform lesion-symptom mapping. Voxel-based morphometry was performed in patients with cerebellar degeneration, and voxel-based lesion-symptom mapping in patients with focal disease. Visual threat eye-blink responses were found to be significantly reduced in patients with cerebellar degeneration. Visual threat eye-blink responses were also reduced in patients with focal disease, but to a lesser extent. Visual threat eye-blink responses declined with age. In patients with cerebellar degeneration the degree of cerebellar atrophy was positively correlated with the reduction of conditioned responses. Voxel-based morphometry showed that two main regions within the superior and inferior parts of the posterior cerebellar cortex contributed to expression of visual threat eye-blink responses bilaterally. Involvement of the more inferior parts of the posterior lobe was

  14. Analysis of EMG Signals in Aggressive and Normal Activities by Using Higher-Order Spectra

    PubMed Central

    Sezgin, Necmettin

    2012-01-01

    The analysis and classification of electromyography (EMG) signals are very important in order to detect some symptoms of diseases, prosthetic arm/leg control, and so on. In this study, an EMG signal was analyzed using bispectrum, which belongs to a family of higher-order spectra. An EMG signal is the electrical potential difference of muscle cells. The EMG signals used in the present study are aggressive or normal actions. The EMG dataset was obtained from the machine learning repository. First, the aggressive and normal EMG activities were analyzed using bispectrum and the quadratic phase coupling of each EMG episode was determined. Next, the features of the analyzed EMG signals were fed into learning machines to separate the aggressive and normal actions. The best classification result was 99.75%, which is sufficient to significantly classify the aggressive and normal actions. PMID:23193379

  15. The EMG activity-acceleration relationship to quantify the optimal vibration load when applying synchronous whole-body vibration.

    PubMed

    Di Giminiani, Riccardo; Masedu, Francesco; Padulo, Johnny; Tihanyi, Jozsef; Valenti, Marco

    2015-12-01

    To date are lacking methodological approaches to individualizing whole-body vibration (WBV) intensity. The aim of this study was: (1) to determine the surface-electromyography-root-mean-square (sEMG(RMS))-acceleration load relationship in the vastus lateralis (VL), vastus medialis (VM), rectus femoris (RF), lateral gastrocnemius (LG) muscles during synchronous WBV, and (2) to assess the reliability of the acceleration corresponding to the maximal sEMG(RMS). Twenty-five sportsman voluntarily took part in this study with a single-group, repeated-measures design. All subjects postured themselves in an isometric half-squat during nine trials in the following conditions: no vibrations and random vibrations of different acceleration loads (from 0.12 to 5.72 g). The sEMG(RMS) were dependent on the acceleration loads in the VL (p = 0.0001), LG (p = 0.0001) and VM (p = 0.011) muscles; while RF was not affected by the acceleration loads (p = 0.508). The comparisons among the sEMG(RMS)-accelerations relationships revealed a significant difference between the LG and the others muscles (p = 0.001). No significant difference was found between the different thigh muscles (p > 0.05). The intra-class correlation coefficient ranged from 0.87 to 0.99 for the measurements performed on the LG, VL and VM. The sEMG(RMS)-acceleration relationship in the VL, VM and LG is a reliable test to individualize the WBV intervention. Copyright © 2015 Elsevier Ltd. All rights reserved.

  16. EOG-sEMG Human Interface for Communication.

    PubMed

    Tamura, Hiroki; Yan, Mingmin; Sakurai, Keiko; Tanno, Koichi

    2016-01-01

    The aim of this study is to present electrooculogram (EOG) and surface electromyogram (sEMG) signals that can be used as a human-computer interface. Establishing an efficient alternative channel for communication without overt speech and hand movements is important for increasing the quality of life for patients suffering from amyotrophic lateral sclerosis, muscular dystrophy, or other illnesses. In this paper, we propose an EOG-sEMG human-computer interface system for communication using both cross-channels and parallel lines channels on the face with the same electrodes. This system could record EOG and sEMG signals as "dual-modality" for pattern recognition simultaneously. Although as much as 4 patterns could be recognized, dealing with the state of the patients, we only choose two classes (left and right motion) of EOG and two classes (left blink and right blink) of sEMG which are easily to be realized for simulation and monitoring task. From the simulation results, our system achieved four-pattern classification with an accuracy of 95.1%.

  17. MVC techniques to normalize trunk muscle EMG in healthy women.

    PubMed

    Vera-Garcia, Francisco J; Moreside, Janice M; McGill, Stuart M

    2010-02-01

    Normalization of the surface electromyogram (EMG) addresses some of the inherent inter-subject and inter-muscular variability of this signal to enable comparison between muscles and people. The aim of this study was to evaluate the effectiveness of several maximal voluntary isometric contraction (MVC) strategies, and identify maximum electromyographic reference values used for normalizing trunk muscle activity. Eight healthy women performed 11 MVC techniques, including trials in which thorax motion was resisted, trials in which pelvis motion was resisted, shoulder rotation and adduction, and un-resisted MVC maneuvers (maximal abdominal hollowing and maximal abdominal bracing). EMG signals were bilaterally collected from upper and lower rectus abdominis, lateral and medial aspects of external oblique, internal oblique, latissimus dorsi, and erector spinae at T9 and L5. A 0.5s moving average window was used to calculate the maximum EMG amplitude of each muscle for each MVC technique. A great inter-subject variability between participants was observed as to which MVC strategy elicited the greatest muscular activity, especially for the oblique abdominals and latissimus dorsi. Since no single test was superior for obtaining maximum electrical activity, it appears that several upper and lower trunk MVC techniques should be performed for EMG normalization in healthy women.

  18. Preferred Sensor Sites for Surface EMG Signal Decomposition

    PubMed Central

    Zaheer, Farah; Roy, Serge H.; De Luca, Carlo J.

    2012-01-01

    Technologies for decomposing the electromyographic (EMG) signal into its constituent motor unit action potential trains have become more practical by the advent of a non-invasive methodology using surface EMG (sEMG) sensors placed on the skin above the muscle of interest (De Luca et al. 2006 and Nawab et al. 2010). This advancement has widespread appeal among researchers and clinicians because of the ease of use, reduced risk of infection, and the greater number of motor unit action potential trains obtained compared to needle sensor techniques. In this study we investigated the influence of the sensor site on the number of identified motor unit action potential trains in six lower limb and one upper limb muscle with the intent of locating preferred sensor sites that provided the greatest number of decomposed motor unit action potential trains, or motor unit yield. Sensor sites rendered varying motor unit yields throughout the surface of a muscle. The preferred sites were located between the center and the tendinous areas of the muscle. The motor unit yield was positively correlated to the signal to noise ratio of the detected sEMG. The signal to noise ratio was inversely related to the thickness of the tissue between the sensor and the muscle fibers. A signal to noise ratio of 3 was found to be the minimum required to obtain a reliable motor unit yield. PMID:22260842

  19. EMG-Based Neural Network Control of Transhumeral Prostheses

    PubMed Central

    Pulliam, Christopher L.; Lambrecht, Joris M.; Kirsch, Robert F.

    2013-01-01

    Upper-limb amputation can cause a great deal of functional impairment for patients, particularly for those with amputation at or above the elbow. Our long-term objective is to improve functional outcomes for patients with amputation by integrating a fully implanted electromyographic (EMG) recording system with a wireless telemetry system that communicates with the patient’s prosthesis. We believe that this should generate a scheme that will allow patients to robustly control multiple degrees of freedom simultaneously. The goal of this study is to evaluate the feasibility of predicting dynamic arm movements (both flexion/extension and pronation/supination) based on EMG signals from a set of muscles that would likely be intact in patients with transhumeral amputation. We recorded movement kinematics and EMG signals from seven muscles during a variety of movements with different complexities. Time-delayed artificial neural networks were then trained offline to predict the measured arm trajectories based on features extracted from the measured EMG signals. We evaluated the relative effectiveness of various muscle subsets. Predicted movement trajectories had average root-mean-square errors of approximately 15.7° and 24.9° and average R2 values of approximately 0.81 and 0.46 for elbow flexion/extension and forearm pronation/supination, respectively. PMID:21938659

  20. Design of a robust EMG sensing interface for pattern classification

    NASA Astrophysics Data System (ADS)

    Huang, He; Zhang, Fan; Sun, Yan L.; He, Haibo

    2010-10-01

    Electromyographic (EMG) pattern classification has been widely investigated for neural control of external devices in order to assist with movements of patients with motor deficits. Classification performance deteriorates due to inevitable disturbances to the sensor interface, which significantly challenges the clinical value of this technique. This study aimed to design a sensor fault detection (SFD) module in the sensor interface to provide reliable EMG pattern classification. This module monitored the recorded signals from individual EMG electrodes and performed a self-recovery strategy to recover the classification performance when one or more sensors were disturbed. To evaluate this design, we applied synthetic disturbances to EMG signals collected from leg muscles of able-bodied subjects and a subject with a transfemoral amputation and compared the accuracies for classifying transitions between different locomotion modes with and without the SFD module. The results showed that the SFD module maintained classification performance when one signal was distorted and recovered about 20% of classification accuracy when four signals were distorted simultaneously. The method was simple to implement. Additionally, these outcomes were observed for all subjects, including the leg amputee, which implies the promise of the designed sensor interface for providing a reliable neural-machine interface for artificial legs.

  1. High-Yield Decomposition of Surface EMG Signals

    PubMed Central

    Nawab, S. Hamid; Chang, Shey-Sheen; De Luca, Carlo J.

    2010-01-01

    Objective Automatic decomposition of surface Electromyographic (sEMG) signals into their constituent motor unit action potential trains (MUAPTs). Methods A small five-pin sensor provides four channels of sEMG signals that are in turn processed by an enhanced artificial intelligence algorithm evolved from a previous proof-of-principle. We tested the technology on sEMG signals from five muscles contracting isometrically at force levels ranging up to 100% of their maximal level, including those that were covered with more than 1.5 cm of adipose tissue. Decomposition accuracy was measured by a new method wherein a signal is first decomposed and then reconstructed and the accuracy is measured by comparison. Results were confirmed by the more established two-source method. Results The number of MUAPTs decomposed varied among muscles and force levels and mostly ranged from 20 to 30, with a maximum of 40. The accuracy of all the firings of the MUAPTs was on average 92.5%, at times reaching 97%. Conclusion Reported technology can reliably perform high-yield decomposition of sEMG signals for isometric contractions up to maximal force levels. Significance The small sensor size and the high yield and accuracy of the decomposition should render this technology useful for motor control studies and clinical investigations. PMID:20430694

  2. High-yield decomposition of surface EMG signals.

    PubMed

    Nawab, S Hamid; Chang, Shey-Sheen; De Luca, Carlo J

    2010-10-01

    Automatic decomposition of surface electromyographic (sEMG) signals into their constituent motor unit action potential trains (MUAPTs). A small five-pin sensor provides four channels of sEMG signals that are in turn processed by an enhanced artificial intelligence algorithm evolved from a previous proof-of-principle. We tested the technology on sEMG signals from five muscles contracting isometrically at force levels ranging up to 100% of their maximal level, including those that were covered with more than 1.5cm of adipose tissue. Decomposition accuracy was measured by a new method wherein a signal is first decomposed and then reconstructed and the accuracy is measured by comparison. Results were confirmed by the more established two-source method. The number of MUAPTs decomposed varied among muscles and force levels and mostly ranged from 20 to 30, and occasionally up to 40. The accuracy of all the firings of the MUAPTs was on average 92.5%, at times reaching 97%. Reported technology can reliably perform high-yield decomposition of sEMG signals for isometric contractions up to maximal force levels. The small sensor size and the high yield and accuracy of the decomposition should render this technology useful for motor control studies and clinical investigations. Copyright 2010 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.

  3. EMG Biofeedback Training Versus Systematic Desensitization for Test Anxiety Reduction

    ERIC Educational Resources Information Center

    Romano, John L.; Cabianca, William A.

    1978-01-01

    Biofeedback training to reduce test anxiety among university students was investigated. Biofeedback training with systematic desensitization was compared to an automated systematic desensitization program not using EMG feedback. Biofeedback training is a useful technique for reducing test anxiety, but not necessarily more effective than systematic…

  4. EOG-sEMG Human Interface for Communication

    PubMed Central

    Tamura, Hiroki; Yan, Mingmin; Sakurai, Keiko; Tanno, Koichi

    2016-01-01

    The aim of this study is to present electrooculogram (EOG) and surface electromyogram (sEMG) signals that can be used as a human-computer interface. Establishing an efficient alternative channel for communication without overt speech and hand movements is important for increasing the quality of life for patients suffering from amyotrophic lateral sclerosis, muscular dystrophy, or other illnesses. In this paper, we propose an EOG-sEMG human-computer interface system for communication using both cross-channels and parallel lines channels on the face with the same electrodes. This system could record EOG and sEMG signals as “dual-modality” for pattern recognition simultaneously. Although as much as 4 patterns could be recognized, dealing with the state of the patients, we only choose two classes (left and right motion) of EOG and two classes (left blink and right blink) of sEMG which are easily to be realized for simulation and monitoring task. From the simulation results, our system achieved four-pattern classification with an accuracy of 95.1%. PMID:27418924

  5. EMG Biofeedback Training Versus Systematic Desensitization for Test Anxiety Reduction

    ERIC Educational Resources Information Center

    Romano, John L.; Cabianca, William A.

    1978-01-01

    Biofeedback training to reduce test anxiety among university students was investigated. Biofeedback training with systematic desensitization was compared to an automated systematic desensitization program not using EMG feedback. Biofeedback training is a useful technique for reducing test anxiety, but not necessarily more effective than systematic…

  6. The Recognition System for the Voluntary Wink with EMG

    NASA Astrophysics Data System (ADS)

    Mizutani, Kengi

    There are many reports about the system controlled by the eye movement in the medical instruments and human technology. In this study, we report a new way of recognition for the voluntary wink with EMG, which can use for the controller about some systems with free hand.

  7. Design of a robust EMG sensing interface for pattern classification.

    PubMed

    Huang, He; Zhang, Fan; Sun, Yan L; He, Haibo

    2010-10-01

    Electromyographic (EMG) pattern classification has been widely investigated for neural control of external devices in order to assist with movements of patients with motor deficits. Classification performance deteriorates due to inevitable disturbances to the sensor interface, which significantly challenges the clinical value of this technique. This study aimed to design a sensor fault detection (SFD) module in the sensor interface to provide reliable EMG pattern classification. This module monitored the recorded signals from individual EMG electrodes and performed a self-recovery strategy to recover the classification performance when one or more sensors were disturbed. To evaluate this design, we applied synthetic disturbances to EMG signals collected from leg muscles of able-bodied subjects and a subject with a transfemoral amputation and compared the accuracies for classifying transitions between different locomotion modes with and without the SFD module. The results showed that the SFD module maintained classification performance when one signal was distorted and recovered about 20% of classification accuracy when four signals were distorted simultaneously. The method was simple to implement. Additionally, these outcomes were observed for all subjects, including the leg amputee, which implies the promise of the designed sensor interface for providing a reliable neural-machine interface for artificial legs.

  8. Effect of isometric horizontal abduction on pectoralis major and serratus anterior EMG activity during three exercises in subjects with scapular winging.

    PubMed

    Park, Kyung-Mi; Cynn, Heon-Seock; Yi, Chung-Hwi; Kwon, Oh-Yun

    2013-04-01

    The aim of this study was to determine the effect of isometric horizontal abduction using Thera-Band during three exercises (forward flexion, scaption, and wall push-up plus) in subjects with scapular winging by investigating the electromyographic (EMG) amplitude of the pectoralis major, serratus anterior and the pectoralis major/serratus anterior activity ratio. Twenty-four males with scapular winging participated in this study. The subjects performed the forward flexion, scaption, and wall push-up plus with and without isometric horizontal abduction using Thera-Band. Surface EMG was used to collect the EMG data of the pectoralis major and serratus anterior during the three exercises. Two-way repeated analyses of variance with two within-subject factors (isometric horizontal abduction condition and exercise type) were used to determine the statistical significance of pectoralis major and serratus anterior EMG activity and the pectoralis major/serratus anterior EMG activity ratio. Pectoralis major EMG activity was significantly lower during forward flexion and wall push-up plus with isometric horizontal abduction, and serratus anterior EMG activity was significantly greater with isometric horizontal abduction. Additionally, the pectoralis major/serratus anterior activity ratio was significantly lower during the forward flexion and wall push-up plus with isometric horizontal abduction. The results of this study suggest that isometric horizontal abduction using Thera-Band can be used as an effective method to facilitate the serratus anterior activity and to reduce excessive pectoralis major activity during exercises for activating serratus anterior. Copyright © 2012 Elsevier Ltd. All rights reserved.

  9. Consequences of prolonged total body immersion in cold water on muscle performance and EMG activity.

    PubMed

    Coulange, Mathieu; Hug, François; Kipson, Nathalie; Robinet, Claude; Desruelle, Anne Virginie; Melin, Bruno; Jimenez, Chantal; Galland, François; Jammes, Yves

    2006-04-01

    The consequences of a prolonged total body immersion in cold water on the muscle function have not been documented yet, and they are the object of this French Navy research program. Ten elite divers were totally immerged and stayed immobile during 6 h in cold (18 and 10 degrees C) water. We measured the maximal voluntary leg extension (maximal voluntary contraction, MVC) and evoked compound muscle potential (M wave) in vastus lateralis and soleus muscles at rest, after a submaximal (60% MVC) isometric extension allowing the measurement of the endurance time (Tlim). The power spectrum of surface electromyograms (EMG) was computed during 60% MVCs. MVCs and 60% MVC maneuvers were repeated four times during the immersion. Data were compared with those obtained in a control group studied in dry air condition during a 6-h session. Total body cooling did not affect MVC nor Tlim. The M wave duration increased in the coolest muscle (soleus), but only at 10 degrees C at rest. There were no further fatigue-induced M wave alterations in both muscles. During 60% the MVCs, a time-dependant increase in the leftward shift of the EMG spectrum occurred at the two temperatures. These EMG changes were absent in the control group of subjects studied in dry air. The plasma lactate concentration was elevated throughout the 18 and mostly the 10 degrees C immersion conditions. Throughout the 18 degrees C immersion study, the resting potassium level did not significantly vary, whereas at 10 degrees C, a significant potassium increase occurred soon and persisted throughout the study. Thus, total body immersion in cold water did not affect the global contractile properties of leg muscles during static efforts but elicited significant alterations in electromyographic events which may be related to the variations of interstitial fluid composition.

  10. EMG signal amplitude normalization technique in stretch-shortening cycle movements.

    PubMed

    Allison, G T; Marshall, R N; Singer, K P

    1993-01-01

    Analysis of functional movements using surface electromyography (EMG) often involves recording both eccentric and concentric muscle activity during a stretch-shorten cycle (SSC). The techniques used for amplitude normalization are varied and are independent of the type of muscle activity involved. The purpose of this study was: (i) to determine the effect of 11 amplitude normalization techniques on the coefficient of variation (CV) during the eccentric and concentric phases of the SSC; and (ii) to establish the effect of the normalization techniques on the EMG signal under variable load and velocity. The EMG signal of the biceps brachii of eight normal subjects was recorded under four SSC conditions and three levels of isometric contraction. The 11 derived normalization values were total rms, mean rms and peak rms (100 ms time constant) for the isometric contractions and the mean rms and peak rms values of the ensemble values for each set of isotonic contractions. Normalization using maximal voluntary isometric contractions (MVIC), irrespective of rms processing (total, mean or peak), demonstrated greater CV above the raw data for both muscle actions. Mean ensemble values and submaximal isometric recordings reduced the CV of concentric data. No amplitude normalization technique reduced the CV for eccentric data under loaded conditions. An ANOVA demonstrated significant (P < 0.01) main effects for load and velocity on concentric raw data and an interaction (P < 0.05) for raw eccentric data. No significant effects were demonstrated for changes in velocity when the data were normalized using mean rms values. The reduction of the CV should not be at the expense of true biological variance and current normalization techniques poorly serve the analysis of eccentric muscle activity during the SSC. Copyright © 1993. Published by Elsevier Ltd.

  11. The Assessment of Muscular Effort, Fatigue, and Physiological Adaptation Using EMG and Wavelet Analysis

    PubMed Central

    Graham, Ryan B.; Wachowiak, Mark P.; Gurd, Brendon J.

    2015-01-01

    Peroxisome proliferator-activated receptor gamma coactivator 1 alpha (PGC-1α) is a transcription factor co-activator that helps coordinate mitochondrial biogenesis within skeletal muscle following exercise. While evidence gleaned from submaximal exercise suggests that intracellular pathways associated with the activation of PGC-1α, as well as the expression of PGC-1α itself are activated to a greater extent following higher intensities of exercise, we have recently shown that this effect does not extend to supramaximal exercise, despite corresponding increases in muscle activation amplitude measured with electromyography (EMG). Spectral analyses of EMG data may provide a more in-depth assessment of changes in muscle electrophysiology occurring across different exercise intensities, and therefore the goal of the present study was to apply continuous wavelet transforms (CWTs) to our previous data to comprehensively evaluate: 1) differences in muscle electrophysiological properties at different exercise intensities (i.e. 73%, 100%, and 133% of peak aerobic power), and 2) muscular effort and fatigue across a single interval of exercise at each intensity, in an attempt to shed mechanistic insight into our previous observations that the increase in PGC-1α is dissociated from exercise intensity following supramaximal exercise. In general, the CWTs revealed that localized muscle fatigue was only greater than the 73% condition in the 133% exercise intensity condition, which directly matched the work rate results. Specifically, there were greater drop-offs in frequency, larger changes in burst power, as well as greater changes in burst area under this intensity, which were already observable during the first interval. As a whole, the results from the present study suggest that supramaximal exercise causes extreme localized muscular fatigue, and it is possible that the blunted PGC-1α effects observed in our previous study are the result of fatigue-associated increases in

  12. Generating Control Commands From Gestures Sensed by EMG

    NASA Technical Reports Server (NTRS)

    Wheeler, Kevin R.; Jorgensen, Charles

    2006-01-01

    An effort is under way to develop noninvasive neuro-electric interfaces through which human operators could control systems as diverse as simple mechanical devices, computers, aircraft, and even spacecraft. The basic idea is to use electrodes on the surface of the skin to acquire electromyographic (EMG) signals associated with gestures, digitize and process the EMG signals to recognize the gestures, and generate digital commands to perform the actions signified by the gestures. In an experimental prototype of such an interface, the EMG signals associated with hand gestures are acquired by use of several pairs of electrodes mounted in sleeves on a subject s forearm (see figure). The EMG signals are sampled and digitized. The resulting time-series data are fed as input to pattern-recognition software that has been trained to distinguish gestures from a given gesture set. The software implements, among other things, hidden Markov models, which are used to recognize the gestures as they are being performed in real time. Thus far, two experiments have been performed on the prototype interface to demonstrate feasibility: an experiment in synthesizing the output of a joystick and an experiment in synthesizing the output of a computer or typewriter keyboard. In the joystick experiment, the EMG signals were processed into joystick commands for a realistic flight simulator for an airplane. The acting pilot reached out into the air, grabbed an imaginary joystick, and pretended to manipulate the joystick to achieve left and right banks and up and down pitches of the simulated airplane. In the keyboard experiment, the subject pretended to type on a numerical keypad, and the EMG signals were processed into keystrokes. The results of the experiments demonstrate the basic feasibility of this method while indicating the need for further research to reduce the incidence of errors (including confusion among gestures). Topics that must be addressed include the numbers and arrangements

  13. Estimating mood variation from MPF of EMG during walking.

    PubMed

    Kinase, Yuta; Venture, Gentiane

    2013-01-01

    The information on the mood included in behavior is classified into nonverbal information, and is included in behavior without necessarily being based on the intention of an agent. Consequently, it is considered that we can estimate the mood from the measurement of the behavior. In this work, we estimate the mood from the surface electromyogram (EMG) information of the muscles of the upper limb during walking. Identification of emotion and mood using EMG information has been done with a variety of methods until now. In addition, it is known that human walking includes information that is specific to the individual and be affected by mood. Therefore, it is thought that the EMG analysis of walking is effective in the identification of human mood. In this work, we made a subject walk in the various mood states and answer psychological tests that measure the mood. We use two types of tasks (music listening and numerical calculation) for evoking different moods. Statistical features of EMG signals are calculated using Fast Fourier Transform (FFT) and Principal Component Analysis (PCA). These statistical features are related with psychological test scores, using regression analysis. In this paper, we have shown the statistical significance of the linear model to predict the variation of mood based on the information on the variation in MPF of EMG data of the muscles of the upper limb during walking with different moods. This shows the validity of such a mapping. However, since the interpretability of the model is still low, it cannot be said that the model is able to accurately represent the mood variation. Creating a model with high accuracy is a key issue in the future.

  14. A Versatile Embedded Platform for EMG Acquisition and Gesture Recognition.

    PubMed

    Benatti, Simone; Casamassima, Filippo; Milosevic, Bojan; Farella, Elisabetta; Schönle, Philipp; Fateh, Schekeb; Burger, Thomas; Huang, Qiuting; Benini, Luca

    2015-10-01

    Wearable devices offer interesting features, such as low cost and user friendliness, but their use for medical applications is an open research topic, given the limited hardware resources they provide. In this paper, we present an embedded solution for real-time EMG-based hand gesture recognition. The work focuses on the multi-level design of the system, integrating the hardware and software components to develop a wearable device capable of acquiring and processing EMG signals for real-time gesture recognition. The system combines the accuracy of a custom analog front end with the flexibility of a low power and high performance microcontroller for on-board processing. Our system achieves the same accuracy of high-end and more expensive active EMG sensors used in applications with strict requirements on signal quality. At the same time, due to its flexible configuration, it can be compared to the few wearable platforms designed for EMG gesture recognition available on market. We demonstrate that we reach similar or better performance while embedding the gesture recognition on board, with the benefit of cost reduction. To validate this approach, we collected a dataset of 7 gestures from 4 users, which were used to evaluate the impact of the number of EMG channels, the number of recognized gestures and the data rate on the recognition accuracy and on the computational demand of the classifier. As a result, we implemented a SVM recognition algorithm capable of real-time performance on the proposed wearable platform, achieving a classification rate of 90%, which is aligned with the state-of-the-art off-line results and a 29.7 mW power consumption, guaranteeing 44 hours of continuous operation with a 400 mAh battery.

  15. Extraction of the EPP Component from the Surface EMG

    PubMed Central

    Kumai, Toshifumi

    2009-01-01

    A surface electromyogram (EMG), especially when recorded near the neuromuscular junction, is expected to contain the endplate potential (EPP) component which can be extracted with an appropriate signal filter. Two factors are important: the EMG must be recorded in monopolar fashion, and the recording must be done so the low frequency signal corresponding the EPP is not eliminated. This report explains how to extract the EPP component from the EMG of the masseter muscle in a human subject. The surface EMG is recorded from eight sites using traditional disc electrodes aligned along over the muscle, with equal inter-electrode distance from the zygomatic arch to the angle of mandible in response to quick gum clenching. A reference electrode is placed on the tip of the nose. The EPP component is extracted from the raw EMGs by applying a high-cut digital filter (2nd dimension Butterworth filter) with a range of 10-35 Hz. When the filter is set to 10 Hz, the extracted EPP wave deflects either negative or positive depending on the recording site. The difference in the polarity reflects the sink-source relation of the end plate current, with the site showing the most negative deflection corresponding to the neuromuscular junction. In the case of the masseter muscle, the neuromuscular junction is estimated to be located in the inferior portion close to the angle of mandible. The EPP component exhibits an interesting oscillation when the cut-off frequency of the high-cut digital filter is set to 30 Hz. The EPP oscillation indicates that muscle contraction is adjusted in an intermittent manner. Abnormal tremors accompanying various sorts of diseases may be substantially due to this EPP oscillation, which becomes slower and is difficult to cease. PMID:20016459

  16. Extraction of the EPP component from the surface EMG.

    PubMed

    Kumai, Toshifumi

    2009-12-16

    A surface electromyogram (EMG), especially when recorded near the neuromuscular junction, is expected to contain the endplate potential (EPP) component which can be extracted with an appropriate signal filter. Two factors are important: the EMG must be recorded in monopolar fashion, and the recording must be done so the low frequency signal corresponding the EPP is not eliminated. This report explains how to extract the EPP component from the EMG of the masseter muscle in a human subject. The surface EMG is recorded from eight sites using traditional disc electrodes aligned along over the muscle, with equal inter-electrode distance from the zygomatic arch to the angle of mandible in response to quick gum clenching. A reference electrode is placed on the tip of the nose. The EPP component is extracted from the raw EMGs by applying a high-cut digital filter (2nd dimension Butterworth filter) with a range of 10-35 Hz. When the filter is set to 10 Hz, the extracted EPP wave deflects either negative or positive depending on the recording site. The difference in the polarity reflects the sink-source relation of the end plate current, with the site showing the most negative deflection corresponding to the neuromuscular junction. In the case of the masseter muscle, the neuromuscular junction is estimated to be located in the inferior portion close to the angle of mandible. The EPP component exhibits an interesting oscillation when the cut-off frequency of the high-cut digital filter is set to 30 Hz. The EPP oscillation indicates that muscle contraction is adjusted in an intermittent manner. Abnormal tremors accompanying various sorts of diseases may be substantially due to this EPP oscillation, which becomes slower and is difficult to cease.

  17. Surface EMG-based Sketching Recognition Using Two Analysis Windows and Gene Expression Programming

    PubMed Central

    Yang, Zhongliang; Chen, Yumiao

    2016-01-01

    Sketching is one of the most important processes in the conceptual stage of design. Previous studies have relied largely on the analyses of sketching process and outcomes; whereas surface electromyographic (sEMG) signals associated with sketching have received little attention. In this study, we propose a method in which 11 basic one-stroke sketching shapes are identified from the sEMG signals generated by the forearm and upper arm muscles from 4 subjects. Time domain features such as integrated electromyography, root mean square and mean absolute value were extracted with analysis windows of two length conditions for pattern recognition. After reducing data dimensionality using principal component analysis, the shapes were classified using Gene Expression Programming (GEP). The performance of the GEP classifier was compared to the Back Propagation neural network (BPNN) and the Elman neural network (ENN). Feature extraction with the short analysis window (250 ms with a 250 ms increment) improved the recognition rate by around 6.4% averagely compared with the long analysis window (2500 ms with a 2500 ms increment). The average recognition rate for the eleven basic one-stroke sketching patterns achieved by the GEP classifier was 96.26% in the training set and 95.62% in the test set, which was superior to the performance of the BPNN and ENN classifiers. The results show that the GEP classifier is able to perform well with either length of the analysis window. Thus, the proposed GEP model show promise for recognizing sketching based on sEMG signals. PMID:27790083

  18. Simple EMG-driven musculoskeletal model enables consistent control performance during path tracing tasks.

    PubMed

    Crouch, Dustin; He Huang

    2016-08-01

    Consistent, robust performance is critical for the utility and user-acceptance of neurally-controlled powered upper limb prostheses. We preliminarily evaluated the performance consistency of an electromyography (EMG)-driven controller based on a two degree-of-freedom musculoskeletal hand model, whose simplified structure is more practical for real-time prosthesis control than existing, complex models. Parameters of four virtual muscles were computed by numerical optimization from an able-bodied subject's kinematic and EMG data collected during wrist and metacarpophalangeal (MCP) flexion/extension movements. The subject attempted to trace a series of paths of different complexity (straight and curved) with the fingertip of a virtual hand displayed on a computer screen; the straight-path tracing tasks were repeated on a second test day to evaluate performance consistency over time. The subject's tracing accuracy during the tasks was consistent both between tasks of varying complexity (i.e. straight vs curved) and between test days when tracing the straight paths. Additionally, task duration, straightness, and smoothness did not significantly differ between the two straight-path test days. The consistent performance between days was achieved even with a very short (~15 seconds) calibration period to re-normalize EMG. The subject also coordinated movements of the wrist and MCP joints simultaneously during the task, much like with healthy, intact limb movement. Our promising results suggest that a musculoskeletal model-based controller may provide consistent and effective performance across a range of operating conditions, making it potentially practical for prosthesis control. Further research is needed to determine whether musculoskeletal model-based control (1) is effective for executing real-world tasks, and (2) can be extended to populations with neuromuscular impairment (e.g. amputation).

  19. Surface EMG-based Sketching Recognition Using Two Analysis Windows and Gene Expression Programming.

    PubMed

    Yang, Zhongliang; Chen, Yumiao

    2016-01-01

    Sketching is one of the most important processes in the conceptual stage of design. Previous studies have relied largely on the analyses of sketching process and outcomes; whereas surface electromyographic (sEMG) signals associated with sketching have received little attention. In this study, we propose a method in which 11 basic one-stroke sketching shapes are identified from the sEMG signals generated by the forearm and upper arm muscles from 4 subjects. Time domain features such as integrated electromyography, root mean square and mean absolute value were extracted with analysis windows of two length conditions for pattern recognition. After reducing data dimensionality using principal component analysis, the shapes were classified using Gene Expression Programming (GEP). The performance of the GEP classifier was compared to the Back Propagation neural network (BPNN) and the Elman neural network (ENN). Feature extraction with the short analysis window (250 ms with a 250 ms increment) improved the recognition rate by around 6.4% averagely compared with the long analysis window (2500 ms with a 2500 ms increment). The average recognition rate for the eleven basic one-stroke sketching patterns achieved by the GEP classifier was 96.26% in the training set and 95.62% in the test set, which was superior to the performance of the BPNN and ENN classifiers. The results show that the GEP classifier is able to perform well with either length of the analysis window. Thus, the proposed GEP model show promise for recognizing sketching based on sEMG signals.

  20. Occurrence of a rhythmic slower wave in EMG prior to a rapid voluntary movement.

    PubMed

    Tanii, K

    1984-05-01

    The aim of the present study was to investigate whether an EMG slower wave prior to a rapid straightening-up movement is associated with motor preparation to perform the movement. The straightening movement was performed at 6 load intensities and under 3 conditions: without any external load; with an additional load; lifting a load. The subject could freely begin the rapid movement from a moderate forward-bending position whenever he was fully ready for the beginning of the movement after he held the bent posture. Bipolar surface EMGs of the erector spinal muscles at the L1 and L4 level, the gluteus maximus muscle and the semitendinosus muscle were led by a pair of skin electrodes with a time constant of 0.03 sec. The signal from the hip goniometer was measured simultaneously to identify the period of the movement. A distinct relationship between the occurrence of the slower wave and both load intensities and conditions was not found. However, the rhythmic slower wave often occurred in the muscles 200-450 msec before the movement. The occurrence of the wave in the muscles was often simultaneous. The signal from the hip goniometer did not change with the occurrence of the slower wave. The amplitude of the slower wave increased frequently. The present results suggest that the slower wave may reflect a significant change of motoneuronal activity in connection with motor preparation to perform the movement.

  1. EMG activation of abdominal muscles in the crunch exercise performed with different external loads.

    PubMed

    Moraes, Antonio C; Pinto, Ronei S; Valamatos, Maria Jose; Valamatos, Maria Joao; Pezarat-Correia, Pedro L; Okano, Alexandre H; Santos, Pedro M; Cabri, Jan M

    2009-05-01

    The aim of this study was to describe by means of surface electromyography the activation of the rectus abdominis, obliquus externus and rectus femoris muscles during the "crunch" abdominal exercise performed with loads. Thirteen subjects performed crunch exercises with loads representing 80, 60, 40 and 20% of the 1-RM (100%) in a random order with the subjects drawing lots, and with a 5 min rest between sets. Surface bipolar EMG electrodes were used. The root mean square of the EMG was calculated for the first repetition of each load. Differences between conditions were tested using a one way ANOVA for repeated measures. Post-hoc Bonferroni tests was used to detect significant differences between specific loads (p<0.05). An average of the percentage values of all studied abdominal muscles was used as a representative value of abdominal synergy (Ab Syn). In general it can be concluded that the abdominal muscles were significantly more recruited in the 100% load condition. Abdominal activation significantly differed between the various loads; however, in general adjacent loads (20 vs. 40% - 1-RM) did not differ. These results suggest that for young, healthy and physically active adults when the objective is progression in the training process of abdominal force, the option ought to be for changes of load superior to 20% of the 1-RM.

  2. EMG and tibial shock upon the first attempt at barefoot running.

    PubMed

    Olin, Evan D; Gutierrez, Gregory M

    2013-04-01

    As a potential means to decrease their risk of injury, many runners are transitioning into barefoot running. Habitually shod runners tend to heel-strike (SHS), landing on their heel first, while barefoot runners tend to mid-foot or toe-strike (BTS), landing flat-footed or on the ball of their foot before bringing down the rest of the foot including the heel. This study compared muscle activity, tibial shock, and knee flexion angle in subjects between shod and barefoot conditions. Eighteen habitually SHS recreational runners ran for 3 separate 7-minute trials, including SHS, barefoot heel-strike (BHS), and BTS conditions. EMG, tibial shock, and knee flexion angle were monitored using bipolar surface electrodes, an accelerometer, and an electrogoniometer, respectively. A one-way MANOVA for repeated measures was conducted and several significant changes were noted between SHS and BTS, including significant increases in average EMG of the medial gastrocnemius (p=.05), average and peak tibial shock (p<.01), and the minimum knee flexion angle (p<.01). Based on our data, the initial change in mechanics may have detrimental effects on the runner. While it has been argued that BTS running may ultimately be less injurious, these data indicate that habitually SHS runners who choose to transition into a BTS technique must undertake the process cautiously.

  3. Detection of and Compensation for EMG Disturbances for Powered Lower Limb Prosthesis Control.

    PubMed

    Spanias, John A; Perreault, Eric J; Hargrove, Levi J

    2016-02-01

    Myoelectric pattern recognition algorithms have been proposed for the control of powered lower limb prostheses, but electromyography (EMG) signal disturbances remain an obstacle to clinical implementation. To address this problem, we used a log-likelihood metric to detect simulated EMG disturbances and real disturbances acquired from EMG containing electrode shift. We found that features extracted from disturbed EMG have much lower log likelihoods than those from undisturbed signals and can be detected using a single threshold acquired from the training data. We designed a linear discriminant analysis (LDA) classifier that uses the log likelihood to decide between using a combination of EMG and mechanical sensors and using mechanical sensors only, to predict locomotion modes. When EMG contained disturbances, our classifier detected those disturbances and disregarded EMG data. Our classifier had significantly lower errors than a standard LDA classifier in the presence of EMG disturbances. The log-likelihood classifier had a low false positive threshold, and thus did not perform significantly differently from the standard LDA classifier when EMG did not contain disturbances. The log-likelihood threshold could also be applied to individual EMG channels, enabling specific channels containing EMG disturbances to be appropriately ignored when making locomotion mode predictions.

  4. An online hybrid BCI system based on SSVEP and EMG

    NASA Astrophysics Data System (ADS)

    Lin, Ke; Cinetto, Andrea; Wang, Yijun; Chen, Xiaogang; Gao, Shangkai; Gao, Xiaorong

    2016-04-01

    Objective. A hybrid brain-computer interface (BCI) is a device combined with at least one other communication system that takes advantage of both parts to build a link between humans and machines. To increase the number of targets and the information transfer rate (ITR), electromyogram (EMG) and steady-state visual evoked potential (SSVEP) were combined to implement a hybrid BCI. A multi-choice selection method based on EMG was developed to enhance the system performance. Approach. A 60-target hybrid BCI speller was built in this study. A single trial was divided into two stages: a stimulation stage and an output selection stage. In the stimulation stage, SSVEP and EMG were used together. Every stimulus flickered at its given frequency to elicit SSVEP. All of the stimuli were divided equally into four sections with the same frequency set. The frequency of each stimulus in a section was different. SSVEPs were used to discriminate targets in the same section. Different sections were classified using EMG signals from the forearm. Subjects were asked to make different number of fists according to the target section. Canonical Correlation Analysis (CCA) and mean filtering was used to classify SSVEP and EMG separately. In the output selection stage, the top two optimal choices were given. The first choice with the highest probability of an accurate classification was the default output of the system. Subjects were required to make a fist to select the second choice only if the second choice was correct. Main results. The online results obtained from ten subjects showed that the mean accurate classification rate and ITR were 81.0% and 83.6 bits min-1 respectively only using the first choice selection. The ITR of the hybrid system was significantly higher than the ITR of any of the two single modalities (EMG: 30.7 bits min-1, SSVEP: 60.2 bits min-1). After the addition of the second choice selection and the correction task, the accurate classification rate and ITR was

  5. An online hybrid BCI system based on SSVEP and EMG.

    PubMed

    Lin, Ke; Cinetto, Andrea; Wang, Yijun; Chen, Xiaogang; Gao, Shangkai; Gao, Xiaorong

    2016-04-01

    A hybrid brain-computer interface (BCI) is a device combined with at least one other communication system that takes advantage of both parts to build a link between humans and machines. To increase the number of targets and the information transfer rate (ITR), electromyogram (EMG) and steady-state visual evoked potential (SSVEP) were combined to implement a hybrid BCI. A multi-choice selection method based on EMG was developed to enhance the system performance. A 60-target hybrid BCI speller was built in this study. A single trial was divided into two stages: a stimulation stage and an output selection stage. In the stimulation stage, SSVEP and EMG were used together. Every stimulus flickered at its given frequency to elicit SSVEP. All of the stimuli were divided equally into four sections with the same frequency set. The frequency of each stimulus in a section was different. SSVEPs were used to discriminate targets in the same section. Different sections were classified using EMG signals from the forearm. Subjects were asked to make different number of fists according to the target section. Canonical Correlation Analysis (CCA) and mean filtering was used to classify SSVEP and EMG separately. In the output selection stage, the top two optimal choices were given. The first choice with the highest probability of an accurate classification was the default output of the system. Subjects were required to make a fist to select the second choice only if the second choice was correct. The online results obtained from ten subjects showed that the mean accurate classification rate and ITR were 81.0% and 83.6 bits min(-1) respectively only using the first choice selection. The ITR of the hybrid system was significantly higher than the ITR of any of the two single modalities (EMG: 30.7 bits min(-1), SSVEP: 60.2 bits min(-1)). After the addition of the second choice selection and the correction task, the accurate classification rate and ITR was enhanced to 85.8% and 90.9 bit

  6. The effect of high pass filtering and non-linear normalization on the EMG-force relationship during sub-maximal finger exertions.

    PubMed

    McDonald, Alison C; Sanei, Kia; Keir, Peter J

    2013-06-01

    Muscle force estimates are important for full understanding of the musculoskeletal system and EMG is a modeling method used to estimate muscle force. The purpose of this investigation was to examine the effect of high pass filtering and non-linear normalization on the EMG-force relationship of sub-maximal finger exertions. Sub-maximal isometric ramp exertions were performed under three conditions (i) extension with restraint at the mid-proximal phalanx, (ii) flexion at the proximal phalanx and (iii) flexion at the distal phalanx. Thirty high pass filter designs were compared to a standardized processing procedure and an exponential fit equation was used for non-linear normalization. High pass filtering significantly reduced the %RMS error and increased the peak cross correlation between EMG and force in the distal flexion condition and in the other two conditions there was a trend towards improving force predictions with high pass filtering. The degree of linearity differed between the three contraction conditions and high pass filtering improved the linearity in all conditions. Non-linear normalization had greater impact on the EMG-force relationship than high pass filtering. The difference in optimal processing parameters suggests that high pass filtering and linearity are dependent on contraction mode as well as the muscle analyzed.

  7. Accuracy assessment of CKC high-density surface EMG decomposition in biceps femoris muscle

    NASA Astrophysics Data System (ADS)

    Marateb, H. R.; McGill, K. C.; Holobar, A.; Lateva, Z. C.; Mansourian, M.; Merletti, R.

    2011-10-01

    The aim of this study was to assess the accuracy of the convolution kernel compensation (CKC) method in decomposing high-density surface EMG (HDsEMG) signals from the pennate biceps femoris long-head muscle. Although the CKC method has already been thoroughly assessed in parallel-fibered muscles, there are several factors that could hinder its performance in pennate muscles. Namely, HDsEMG signals from pennate and parallel-fibered muscles differ considerably in terms of the number of detectable motor units (MUs) and the spatial distribution of the motor-unit action potentials (MUAPs). In this study, monopolar surface EMG signals were recorded from five normal subjects during low-force voluntary isometric contractions using a 92-channel electrode grid with 8 mm inter-electrode distances. Intramuscular EMG (iEMG) signals were recorded concurrently using monopolar needles. The HDsEMG and iEMG signals were independently decomposed into MUAP trains, and the iEMG results were verified using a rigorous a posteriori statistical analysis. HDsEMG decomposition identified from 2 to 30 MUAP trains per contraction. 3 ± 2 of these trains were also reliably detected by iEMG decomposition. The measured CKC decomposition accuracy of these common trains over a selected 10 s interval was 91.5 ± 5.8%. The other trains were not assessed. The significant factors that affected CKC decomposition accuracy were the number of HDsEMG channels that were free of technical artifact and the distinguishability of the MUAPs in the HDsEMG signal (P < 0.05). These results show that the CKC method reliably identifies at least a subset of MUAP trains in HDsEMG signals from low force contractions in pennate muscles.

  8. Heart rate variability (HRV) and muscular system activity (EMG) in cases of crash threat during simulated driving of a passenger car.

    PubMed

    Zużewicz, Krystyna; Roman-Liu, Danuta; Konarska, Maria; Bartuzi, Paweł; Matusiak, Krzysztof; Korczak, Dariusz; Lozia, Zbigniew; Guzek, Marek

    2013-10-01

    The aim of the study was to verify whether simultaneous responses from the muscular and circulatory system occur in the driver's body under simulated conditions of a crash threat. The study was carried out in a passenger car driving simulator. The crash was included in the driving test scenario developed in an urban setting. In the group of 22 young male subjects, two physiological signals - ECG and EMG were continuously recorded. The length of the RR interval in the ECG signal was assessed. A HRV analysis was performed in the time and frequency domains for 1-minute record segments at rest (seated position), during undisturbed driving as well as during and several minutes after the crash. For the left and right side muscles: m. trapezius (TR) and m. flexor digitorum superficialis (FDS), the EMG signal amplitude was determined. The percentage of maximal voluntary contraction (MVC) was compared during driving and during the crash. As for the ECG signal, it was found that in most of the drivers changes occurred in the parameter values reflecting HRV in the time domain. Significant changes were noted in the mean length of RR intervals (mRR). As for the EMG signal, the changes in the amplitude concerned the signal recorded from the FDS muscle. The changes in ECG and EMG were simultaneous in half of the cases. Such parameters as mRR (ECG signal) and FDS-L amplitude (EMG signal) were the responses to accident risk. Under simulated conditions, responses from the circulatory and musculoskeletal systems are not always simultaneous. The results indicate that a more complete driver's response to a crash in road traffic is obtained based on parallel recording of two physiological signals (ECG and EMG).

  9. Classification of EMG signals using PCA and FFT.

    PubMed

    Güler, Nihal Fatma; Koçer, Sabri

    2005-06-01

    In this study, the fast Fourier transform (FFT) analysis was applied to EMG signals recorded from ulnar nerves of 59 patients to interpret data. The data of the patients were diagnosed by the neurologists as 19 patients were normal, 20 patients had neuropathy and 20 patients had myopathy. The amount of FFT coefficients had been reduced by using principal components analysis (PCA). This would facilitate calculation and storage of EMG data. PCA coefficients were applied to multilayer perceptron (MLP) and support vector machine (SVM) and both classified systems of performance values were computed. Consequently, the results show that SVM has high anticipation level in the diagnosis of neuromuscular disorders. It is proved that its test performance is high compared with MLP.

  10. Power independent EMG based gesture recognition for robotics.

    PubMed

    Li, Ling; Looney, David; Park, Cheolsoo; Rehman, Naveed U; Mandic, Danilo P

    2011-01-01

    A novel method for detecting muscle contraction is presented. This method is further developed for identifying four different gestures to facilitate a hand gesture controlled robot system. It is achieved based on surface Electromyograph (EMG) measurements of groups of arm muscles. The cross-information is preserved through a simultaneous processing of EMG channels using a recent multivariate extension of Empirical Mode Decomposition (EMD). Next, phase synchrony measures are employed to make the system robust to different power levels due to electrode placements and impedances. The multiple pairwise muscle synchronies are used as features of a discrete gesture space comprising four gestures (flexion, extension, pronation, supination). Simulations on real-time robot control illustrate the enhanced accuracy and robustness of the proposed methodology.

  11. Tackling speaking mode varieties in EMG-based speech recognition.

    PubMed

    Wand, Michael; Janke, Matthias; Schultz, Tanja

    2014-10-01

    An electromyographic (EMG) silent speech recognizer is a system that recognizes speech by capturing the electric potentials of the human articulatory muscles, thus enabling the user to communicate silently. After having established a baseline EMG-based continuous speech recognizer, in this paper, we investigate speaking mode variations, i.e., discrepancies between audible and silent speech that deteriorate recognition accuracy. We introduce multimode systems that allow seamless switching between audible and silent speech, investigate different measures which quantify speaking mode differences, and present the spectral mapping algorithm, which improves the word error rate (WER) on silent speech by up to 14.3% relative. Our best average silent speech WER is 34.7%, and our best WER on audibly spoken speech is 16.8%.

  12. Muscular fatigue detection using sEMG in dynamic contractions.

    PubMed

    Bueno, Diana R; Lizano, J M; Montano, L

    2015-08-01

    In this work we have studied different indicators of muscle fatigue from the electrical signal produced by the muscles when contract (sEMG or EMG: surface electromyography): Mean Frequency of the power spectrum (MNF), Median Frequency (Fmed), Dimitrov Spectral Index (FInsm5), Root Mean Square (RMS), and Zerocrossing (ZC). The most reliable features are selected to develop a detection algorithm that estimates muscle fatigue. The approach used in the algorithm is probabilistic and is based on the technique of Gaussian Mixture Model (GMM). The system is divided into two stages: training and validation. During training, the algorithm learns the distribution of data regarding fatigue evolution; after that, the algorithm is validated with data that have not been used to train. Therefore, two experimental sessions have been performed with 6 healthy subjects for biceps.

  13. Voiceless Bangla vowel recognition using sEMG signal.

    PubMed

    Mostafa, S S; Awal, M A; Ahmad, M; Rashid, M A

    2016-01-01

    Some people cannot produce sound although their facial muscles work properly due to having problem in their vocal cords. Therefore, recognition of alphabets as well as sentences uttered by these voiceless people is a complex task. This paper proposes a novel method to solve this problem using non-invasive surface Electromyogram (sEMG). Firstly, eleven Bangla vowels are pronounced and sEMG signals are recorded at the same time. Different features are extracted and mRMR feature selection algorithm is then applied to select prominent feature subset from the large feature vector. After that, these prominent features subset is applied in the Artificial Neural Network for vowel classification. This novel Bangla vowel classification method can offer a significant contribution in voice synthesis as well as in speech communication. The result of this experiment shows an overall accuracy of 82.3 % with fewer features compared to other studies in different languages.

  14. Electromyographic (EMG) neuromonitoring in otolaryngology-head and neck surgery.

    PubMed

    Dillon, Francis X

    2010-09-01

    Intraoperative neuromonitoring (IONM) is a relatively recent advance in electromyography (EMG) applied to otolaryngology-head and neck surgery. Its purpose is to allow real-time identification and functional assessment of vulnerable nerves during surgery. The nerves most often monitored in head and neck surgery are the motor branch of the facial nerve (VII), the recurrent or inferior laryngeal nerves (X), the vagus nerve (X), and the spinal accessory nerve (XI), with other cranial lower nerves monitored less frequently. Morbidity from trauma to these nerves is significant and obvious, such as unilateral facial paresis. Although functional restorative surgery is usually considered to repair the effects of such an insult, the importance of preventing nerve injury in head and neck surgery is obvious. This article focuses on the anesthetic considerations pertinent to IONM of peripheral cranial nerves during otolaryngologic-head and neck surgery. The specific modality of IONM is EMG, both spontaneous and evoked.

  15. EMG signal morphology in essential tremor and Parkinson's disease.

    PubMed

    Ruonala, V; Meigal, A; Rissanen, S M; Airaksinen, O; Kankaanpaa, M; Karjalainen, P A

    2013-01-01

    The aim of this work was to differentiate patients with essential tremor from patients with Parkinson's disease. The electromyographic signal from the biceps brachii muscle was measured during isometric tension from 17 patients with essential tremor, 35 patients with Parkinson's disease, and 40 healthy controls. The EMG signals were high pass filtered and divided to smaller segments from which histograms were calculated using 200 histogram bins. EMG signal histogram shape was analysed with a feature dimension reduction method, the principal component analysis, and the shape parameters were used to differentiate between different patient groups. The height of the histogram and the side difference between left and right hand were the best discriminators between essential tremor and Parkinson's disease groups. With this method, it was possible to discriminate 13/17 patients with essential tremor from 26/35 patients with Parkinson's disease and 14/17 patients with essential tremor from 29/40 healthy controls.

  16. Haptic feedback enhances grip force control of sEMG-controlled prosthetic hands in targeted reinnervation amputees.

    PubMed

    Kim, Keehoon; Colgate, J Edward

    2012-11-01

    In this study, we hypothesized that haptic feedback would enhance grip force control of surface electromyography (sEMG)-controlled prosthetic hands for targeted reinnervation (TR) amputees. A new miniature haptic device, a tactor, that can deliver touch, pressure, shear, and temperature sensation, allows modality-matching haptic feedback. TR surgery that creates sensory regions on the patient's skin that refer to the surface of the missing limb allows somatotopic-matching haptic feedback. This paper evaluates the hypothesis via an sEMG-controlled virtual prosthetic arm operated by TR amputees under diverse haptic feedback conditions. The results indicate that the grip force control is significantly enhanced via the haptic feedback. However, the simultaneous display of two haptic channels (pressure and shear) does not enhance, but instead degrades, grip force control.

  17. A neuromusculoskeletal model of the human lower limb: towards EMG-driven actuation of multiple joints in powered orthoses.

    PubMed

    Sartori, Massimo; Reggiani, Monica; Lloyd, David G; Pagello, Enrico

    2011-01-01

    This paper presents a novel neuromusculoskeletal (NMS) model of the human lower limb that uses the electromyo-graphic (EMG) signals from 16 muscles to estimate forces generated by 34 musculotendon actuators and the resulting joint moments at the hip, knee and ankle joints during varied contractile conditions. Our proposed methodology allows overcoming limitations on force computation shown by currently available NMS models, which constrain the operation of muscles to satisfy joint moments about one single degree of freedom (DOF) only (i.e. knee flexion-extension). The design of advanced human machine interfaces can benefit from the application of our proposed multi-DOF NMS model. The better estimates of the human internal state it provides with respect to single-DOF NMS models, will allow designing more intuitive human-machine interfaces for the simultaneous EMG-driven actuation of multiple joints in lower limb powered orthoses.

  18. In vivo EMG biofeedback in violin and viola pedagogy.

    PubMed

    LeVine, W R; Irvine, J K

    1984-06-01

    In vivo EMG biofeedback was found to be an effective pedagogical tool for removing unwanted left-hand tension in nine violin and viola players. Improvement occurred rapidly and persisted throughout a 5-month follow-up period. Further studies will be necessary to assess the effect of biofeedback independent of placebo effects. The brevity of the method and the magnitude of improvement warrant further investigation.

  19. EMG study for perioral facial muscles function during mastication.

    PubMed

    Hanawa, S; Tsuboi, A; Watanabe, M; Sasaki, K

    2008-03-01

    This study aimed to clarify the temporal and quantitative modulation in the orbicularis oris (OO) and buccinator (BUC) muscle activities during mastication. Ten healthy males (26.9 +/- 1.0 years) participated. Electromyograms (EMGs) of the facial muscles were recorded with fine wire electrodes when chewing the chewing gum (one to four sticks) and peanuts (one to five pieces). Surface EMGs of the masseter (MAS) and digastric muscles were recorded simultaneously. EMGs of the OO and BUC showed rhythmic single-peaked bursts corresponding to the jaw-opening phase of chewing cycles. The total cycle lengths were constant regardless of the food amount. Integrated EMGs of the OO changed significantly when the amount of both foods changed (anova: P < 0.05). Those of the BUC changed significantly with the amount of gum changed (P < 0.05), but did not change with the amount of peanuts changed. The burst duration of OO changed significantly when the amount of gum changed during ipsilateral chewing (P < 0.05). When the amount of peanuts changed during ipsilateral chewing, the onset of OO and the peak of BUC based on the onset of MAS activity changed significantly (P < 0.05). However, the onset, peak and offset of the OO and BUC based on the offset of MAS did not change regardless of the amounts chewed. The changes of the OO and BUC activities may derive from chewing-generated sensory inputs in accordance with the physical property of food in part, which would relate to the function of these muscles during mastication.

  20. Individual finger classification from surface EMG: Influence of electrode set.

    PubMed

    Celadon, Nicolo; Dosen, Strahinja; Paleari, Marco; Farina, Dario; Ariano, Paolo

    2015-01-01

    The aim of this work was to minimize the number of channels, determining acceptable electrode locations and optimizing electrode-recording configurations to decode isometric flexion and extension of individual fingers. Nine healthy subjects performed cyclical isometric contractions activating individual fingers. During the experiment they tracked a moving visual marker indicating the contraction type (flexion/extension), desired activation level and the finger that should be employed. Surface electromyography (sEMG) signals were detected from the forearm muscles using a matrix of 192 channels (24 longitudinal columns and 8 transversal rows, 10 mm inter-electrode distance). The classification was evaluated in the context of a linear discriminant analysis (LDA) with different sets of EMG electrodes: A) one linear array of 8 electrodes, B) two arrays of 8 electrodes each, C) a set with one electrode on the barycenter of each sEMG activity area, D) all the recorded channels. The results showed that the classification accuracy depended on the electrode set (F=14.67, p<;0.001). The best reduction approaches were the barycenter calculation and the use of two linear arrays of electrodes, which performed similarly to each other (both > 82% of average success rate). Considering the computation time and electrode positioning, it is concluded that two arrays of 8 electrodes provide an optimal configuration to classify the isometric flexion and extension of individual fingers.

  1. Baseline Adaptive Wavelet Thresholding Technique for sEMG Denoising

    NASA Astrophysics Data System (ADS)

    Bartolomeo, L.; Zecca, M.; Sessa, S.; Lin, Z.; Mukaeda, Y.; Ishii, H.; Takanishi, Atsuo

    2011-06-01

    The surface Electromyography (sEMG) signal is affected by different sources of noises: current technology is considerably robust to the interferences of the power line or the cable motion artifacts, but still there are many limitations with the baseline and the movement artifact noise. In particular, these sources have frequency spectra that include also the low-frequency components of the sEMG frequency spectrum; therefore, a standard all-bandwidth filtering could alter important information. The Wavelet denoising method has been demonstrated to be a powerful solution in processing white Gaussian noise in biological signals. In this paper we introduce a new technique for the denoising of the sEMG signal: by using the baseline of the signal before the task, we estimate the thresholds to apply to the Wavelet thresholding procedure. The experiments have been performed on ten healthy subjects, by placing the electrodes on the Extensor Carpi Ulnaris and Triceps Brachii on right upper and lower arms, and performing a flexion and extension of the right wrist. An Inertial Measurement Unit, developed in our group, has been used to recognize the movements of the hands to segment the exercise and the pre-task baseline. Finally, we show better performances of the proposed method in term of noise cancellation and distortion of the signal, quantified by a new suggested indicator of denoising quality, compared to the standard Donoho technique.

  2. Rigorous a posteriori assessment of accuracy in EMG decomposition.

    PubMed

    McGill, Kevin C; Marateb, Hamid R

    2011-02-01

    If electromyography (EMG) decomposition is to be a useful tool for scientific investigation, it is essential to know that the results are accurate. Because of background noise, waveform variability, motor-unit action potential (MUAP) indistinguishability, and perplexing superpositions, accuracy assessment is not straightforward. This paper presents a rigorous statistical method for assessing decomposition accuracy based only on evidence from the signal itself. The method uses statistical decision theory in a Bayesian framework to integrate all the shape- and firing-time-related information in the signal to compute an objective a posteriori measure of confidence in the accuracy of each discharge in the decomposition. The assessment is based on the estimated statistical properties of the MUAPs and noise and takes into account the relative likelihood of every other possible decomposition. The method was tested on 3 pairs of real EMG signals containing 4-7 active MUAP trains per signal that had been decomposed by a human expert. It rated 97% of the identified MUAP discharges as accurate to within ± 0.5 ms with a confidence level of 99%, and detected six decomposition errors. Cross-checking between signal pairs verified all but two of these assertions. These results demonstrate that the approach is reliable and practical for real EMG signals.

  3. Multidimensional EMG-based assessment of walking dynamics.

    PubMed

    Jansen, Ben H; Miller, Vonda H; Mavrofrides, Demetrios C; Stegink Jansen, Caroline W

    2003-09-01

    The electromyogram (EMG) provides a measure of a muscle's involvement in the execution of a motor task. Successful completion of an activity, such as walking, depends on the efficient motor control of a group of muscles. In this paper, we present a method to quantify the intricate phasing and activation levels of a group of muscles during gait. At the core of our method is a multidimensional representation of the EMG activity observed during a single stride. This representation is referred to as a "trajectory." A hierarchical clustering procedure is used to identify representative classes of muscle activity patterns. The relative frequencies with which these motor patterns occur during a session (i.e., a series of consecutive strides) are expressed as histograms. Changes in walking strategy will be reflected as changes in the relative frequency with which specific gait patterns occur. This method was evaluated using EMG data obtained during walking on a level and a moderately-inclined treadmill. It was found that the histogram changes due to artificially altered gait are significantly larger than the changes due to normal day-to-day variability.

  4. Evaluation of EMG processing techniques using Information Theory

    PubMed Central

    2010-01-01

    Background Electromyographic signals can be used in biomedical engineering and/or rehabilitation field, as potential sources of control for prosthetics and orthotics. In such applications, digital processing techniques are necessary to follow efficient and effectively the changes in the physiological characteristics produced by a muscular contraction. In this paper, two methods based on information theory are proposed to evaluate the processing techniques. Methods These methods determine the amount of information that a processing technique is able to extract from EMG signals. The processing techniques evaluated with these methods were: absolute mean value (AMV), RMS values, variance values (VAR) and difference absolute mean value (DAMV). EMG signals from the middle deltoid during abduction and adduction movement of the arm in the scapular plane was registered, for static and dynamic contractions. The optimal window length (segmentation), abduction and adduction movements and inter-electrode distance were also analyzed. Results Using the optimal segmentation (200 ms and 300 ms in static and dynamic contractions, respectively) the best processing techniques were: RMS, AMV and VAR in static contractions, and only the RMS in dynamic contractions. Using the RMS of EMG signal, variations in the amount of information between the abduction and adduction movements were observed. Conclusions Although the evaluation methods proposed here were applied to standard processing techniques, these methods can also be considered as alternatives tools to evaluate new processing techniques in different areas of electrophysiology. PMID:21073705

  5. Evaluation of EMG processing techniques using Information Theory.

    PubMed

    Farfán, Fernando D; Politti, Julio C; Felice, Carmelo J

    2010-11-12

    Electromyographic signals can be used in biomedical engineering and/or rehabilitation field, as potential sources of control for prosthetics and orthotics. In such applications, digital processing techniques are necessary to follow efficient and effectively the changes in the physiological characteristics produced by a muscular contraction. In this paper, two methods based on information theory are proposed to evaluate the processing techniques. These methods determine the amount of information that a processing technique is able to extract from EMG signals. The processing techniques evaluated with these methods were: absolute mean value (AMV), RMS values, variance values (VAR) and difference absolute mean value (DAMV). EMG signals from the middle deltoid during abduction and adduction movement of the arm in the scapular plane was registered, for static and dynamic contractions. The optimal window length (segmentation), abduction and adduction movements and inter-electrode distance were also analyzed. Using the optimal segmentation (200 ms and 300 ms in static and dynamic contractions, respectively) the best processing techniques were: RMS, AMV and VAR in static contractions, and only the RMS in dynamic contractions. Using the RMS of EMG signal, variations in the amount of information between the abduction and adduction movements were observed. Although the evaluation methods proposed here were applied to standard processing techniques, these methods can also be considered as alternatives tools to evaluate new processing techniques in different areas of electrophysiology.

  6. An EMG-Controlled Robotic Hand Exoskeleton for Bilateral Rehabilitation.

    PubMed

    Leonardis, Daniele; Barsotti, Michele; Loconsole, Claudio; Solazzi, Massimiliano; Troncossi, Marco; Mazzotti, Claudio; Castelli, Vincenzo Parenti; Procopio, Caterina; Lamola, Giuseppe; Chisari, Carmelo; Bergamasco, Massimo; Frisoli, Antonio

    2015-01-01

    This paper presents a novel electromyography (EMG)-driven hand exoskeleton for bilateral rehabilitation of grasping in stroke. The developed hand exoskeleton was designed with two distinctive features: (a) kinematics with intrinsic adaptability to patient's hand size, and (b) free-palm and free-fingertip design, preserving the residual sensory perceptual capability of touch during assistance in grasping of real objects. In the envisaged bilateral training strategy, the patient's non paretic hand acted as guidance for the paretic hand in grasping tasks. Grasping force exerted by the non paretic hand was estimated in real-time from EMG signals, and then replicated as robotic assistance for the paretic hand by means of the hand-exoskeleton. Estimation of the grasping force through EMG allowed to perform rehabilitation exercises with any, non sensorized, graspable objects. This paper presents the system design, development, and experimental evaluation. Experiments were performed within a group of six healthy subjects and two chronic stroke patients, executing robotic-assisted grasping tasks. Results related to performance in estimation and modulation of the robotic assistance, and to the outcomes of the pilot rehabilitation sessions with stroke patients, positively support validity of the proposed approach for application in stroke rehabilitation.

  7. Electromyographic muscle EMG activity in mouth and nasal breathing children.

    PubMed

    Ribeiro, Eliane C; Marchiori, Susana C; da Silva, Ana Maria T

    2004-04-01

    Mouth breathing may cause changes in muscle activity, because an upper airway obstruction leads may cause a person to extend his/her head forward, demanding a higher inspiratory effort on the accessory muscles (sternocleidomastoids). This purpose of this study is to compare, using electromyography (EMG), the activity pattern the sternocleidomastoid and upper trapezius muscles in mouth breathing children and nasal breathing children. Forty-six children, ages 8-12 years, 33 male and 13 female were included. The selected children were divided into two groups: Group I consisted of 26 mouth breathing children, and Group II, 20 nasal breathing children. EMG recordings were made using surface electrodes bilaterally in the areas of the sternocleidomastoideus and upper trapezius muscles, while relaxed and during maximal voluntary contraction. The data were analyzed using the Kruskall-Wallis statistical test. The results indicated higher activity during relaxation and lower activity during maximal voluntary contraction in mouth breathers when compared to the nasal breathers. It is suggested that the activity pattern of the sternocleidomastoid and upper trapezius muscles differs between mouth breathing children and nasal breathing children. This may be attributed to changes in body posture which causes muscular imbalance. Because of the limitations of surface EMG, the results need to be confirmed by adding force measurements and repeating the experiments with matched subjects.

  8. [Newly devised subcutaneous needle electrodes for EMG recording].

    PubMed

    Okabe, Y; Koibuchi, H; Ai, M; Hibi, H; Haketa, T

    1991-09-01

    Subcutaneous needle electrodes made of stainless steel were newly devised for ease of handling and perfect insulation. This needle (phi 0.20 mm) is used for acupuncture. The electrodes had the capability to record the EMG activity easily from a certain muscle. Then, the EMG activities of the masseter muscle were recorded with both these needle electrodes and surface electrodes and the results were compared. 1. Insertion of the electrodes into the subcutaneous tissue was easily performed because of the application of the acupuncture needle and their lightness of 0.2g was effective in fixing the electrodes on the skin without causing any tension. 2. After the insertion of the needle electrodes, the impedance showed below 5 kohm immediately, and the EMG recordings during biting could be simply achieved with great stability. 3. The action potential from the needle electrodes was less than that from the surface ones. The former reacted more sensitively to the change in the distance between the electrodes, compared with the latter.

  9. Alteration of Surface EMG amplitude levels of five major trunk muscles by defined electrode location displacement.

    PubMed

    Huebner, Agnes; Faenger, Bernd; Schenk, Philipp; Scholle, Hans-Christoph; Anders, Christoph

    2015-04-01

    Exact electrode positioning is vital for obtaining reliable results in Surface EMG. This study aimed at systematically assessing the influence of defined electrode shifts on measured Surface EMG amplitudes of trunk muscles in a group of 15 middle aged healthy male subjects. The following leftsided muscles were investigated: rectus abdominis muscle, internal and external oblique abdominal muscles, lumbar multifidus muscle, and longissimus muscle. In addition to the recommended electrode positions, extra electrodes were placed parallel to these and along muscle fiber direction. Measurements were performed under isometric conditions in upright body position. Gradually changing, but defined loads were applied considering subject's upper body weight. For the abdominal muscles amplitude differences varied considerably depending on load level, magnitude, and direction. For both back muscles amplitudes dropped consistently but rather little for parallel electrode displacements. However, for the longissimus muscle a caudal electrode shift resulted in an amplitude increase of similar extent and independent from load level. Influence of electrode position variations can be proven for all trunk muscles but are more evident in abdominal than back muscles. Those muscle-specific effects confirm the necessity for an exact definition of electrode positioning to allow comparisons between individual subjects, groups of subjects, and studies. Copyright © 2014 Elsevier Ltd. All rights reserved.

  10. Comparing tomographic EEG neurofeedback and EMG biofeedback in children with attention-deficit/hyperactivity disorder.

    PubMed

    Maurizio, Stefano; Liechti, Martina Daniela; Heinrich, Hartmut; Jäncke, Lutz; Steinhausen, Hans-Christoph; Walitza, Susanne; Brandeis, Daniel; Drechsler, Renate

    2014-01-01

    Two types of biofeedback (BF), tomographic electroencephalogram (EEG) neurofeedback (NF) and electromyographic biofeedback (EMG-BF), both with phasic and tonic protocols, were compared for treatment effects and specificity in attention-deficit/hyperactivity disorder (ADHD). Thirteen children with ADHD trained their brain activity in the anterior cingulate cortex (ACC), and twelve trained activity of arm muscles involved in fine motor skills. In each training session, resting state 24-channel EEG and training performances were recorded. Both groups showed similar behavioral improvements and artifact reduction in selected conditions, with no significant advantages despite medium effect sizes on primary outcomes for NF. Only the EMG-BF group, however, showed clear improvement in training regulation performance, and specific motor coordination effects. The NF group tended to present individual normalization of trained frequency bands in the ACC during rest across training. The results provide evidence for some specific effects in our small sample, albeit only to a small extent. Copyright © 2013 Elsevier B.V. All rights reserved.

  11. Electrophysiologic behavior modification of frontal EMG in cerebral-palsied children.

    PubMed

    Finley, W W; Niman, C A; Standley, J; Wansley, R A

    1977-03-01

    Four cerebral-palsied children participated in the following ABAB design: speech and motor pre-electrophysiologic behavior modification (EMB) evaluation; frontal EMG EMB, six weeks; speech and motor post-EBM evaluation; six weeks no training; speech and motor reevaluation; EMG EBM, four weeks; speech and motor evaluation. Auditory and visual feedback of frontal EMG was monitored by cumulative integration of frontal EMG voltage. The children were shaped by setting a cumulative voltage threshold (CVT). If the child's cumulative integrated frontal EMG voltage fell below the CVT at the end of each 60-sec epoch, a reward was automatically dispensed from a Universal Feeder. Frontal EMG decreased significantly over the initial twelve trials. Correspondingly, improvement was noted for the children in speech and motor skills. Follow-up six weeks later showed increased frontal EMG voltage and deterioration of speech and motor function. Reinstitution of frontal EMG EBM produced reacquisition of low frontal EMG and some recovery of speech and motor function. Collectively, these results indicate that frontal EMG EBM shows promise as an additional treatment modality in the habilitation of cerebral palsy children with spasticity.

  12. Effects of innovative virtual reality game and EMG biofeedback on neuromotor control in cerebral palsy.

    PubMed

    Yoo, Ji Won; Lee, Dong Ryul; Sim, Yon Ju; You, Joshua H; Kim, Cheol J

    2014-01-01

    Sensorimotor control dysfunction or dyskinesia is a hallmark of neuromuscular impairment in children with cerebral palsy (CP), and is often implicated in reaching and grasping deficiencies due to a neuromuscular imbalance between the triceps and biceps. To mitigate such muscle imbalances, an innovative electromyography (EMG)-virtual reality (VR) biofeedback system were designed to provide accurate information about muscle activation and motivation. However, the clinical efficacy of this approach has not yet been determined in children with CP. The purpose of this study was to investigate the effectiveness of a combined EMG biofeedback and VR (EMG-VR biofeedback) intervention system to improve muscle imbalance between triceps and biceps during reaching movements in children with spastic CP. Raw EMG signals were recorded at a sampling rate of 1,000 Hz, band-pass filtered between 20-450 Hz, and notch-filtered at 60 Hz during elbow flexion and extension movements. EMG data were then processed using MyoResearch Master Edition 1.08 XP software. All participants underwent both interventions consisting of the EMG-VR biofeedback combination and EMG biofeedback alone. EMG analysis resulted in improved muscle activation in the underactive triceps while decreasing overactive or hypertonic biceps in the EMG-VR biofeedback compared with EMG biofeedback. The muscle imbalance ratio between the triceps and biceps was consistently improved. The present study is the first clinical trial to provide evidence for the additive benefits of VR intervention for enhancing the upper limb function of children with spastic CP.

  13. The extraction of neural strategies from the surface EMG: an update.

    PubMed

    Farina, Dario; Merletti, Roberto; Enoka, Roger M

    2014-12-01

    A surface EMG signal represents the linear transformation of motor neuron discharge times by the compound action potentials of the innervated muscle fibers and is often used as a source of information about neural activation of muscle. However, retrieving the embedded neural code from a surface EMG signal is extremely challenging. Most studies use indirect approaches in which selected features of the signal are interpreted as indicating certain characteristics of the neural code. These indirect associations are constrained by limitations that have been detailed previously (Farina D, Merletti R, Enoka RM. J Appl Physiol 96: 1486-1495, 2004) and are generally difficult to overcome. In an update on these issues, the current review extends the discussion to EMG-based coherence methods for assessing neural connectivity. We focus first on EMG amplitude cancellation, which intrinsically limits the association between EMG amplitude and the intensity of the neural activation and then discuss the limitations of coherence methods (EEG-EMG, EMG-EMG) as a way to assess the strength of the transmission of synaptic inputs into trains of motor unit action potentials. The debated influence of rectification on EMG spectral analysis and coherence measures is also discussed. Alternatively, there have been a number of attempts to identify the neural information directly by decomposing surface EMG signals into the discharge times of motor unit action potentials. The application of this approach is extremely powerful, but validation remains a central issue.

  14. A preliminary investigation of reproducibility of EMG signals during daytime masticatory muscle activity using a portable EMG logging device.

    PubMed

    Omoto, Katsuhiro; Shigemoto, Shuji; Suzuki, Yoshitaka; Nakamura, Mayumi; Okura, Kazuo; Nishigawa, Keisuke; Goto, Nami; Rodis, Omar Marianito Maningo; Matsuka, Yoshizo

    2015-08-01

    Continuous parafunctional masseter muscle activities (MMA) that are associated with daytime bruxism have been suspected to be one of the main pathoetiology for orofacial pain. The purpose of this study was to examine the long-term stability and reliability of daytime EMG measurement of MMA using a portable device (Actiwave; CamNtech Ltd). Daytime masseter muscle EMG of five subjects were recorded for four days in their normal living environment. There was no significant time dependent effect on EMG amplitude during recording period. A total of 4923 MMA events were detected in all analysis periods (129.4h) and classified into phasic type (1209 events, 24.6%), tonic type (1759 events, 37.0%), and mixed type (1377 events, 28.0%). There was no significant difference in the number of occurrence among three MMA types. With respect to the duration and peak MMA, there were significant differences among three MMA types. The result of this study indicated that Actiwave can be used to measure MMA events during daytime with high stability and reliability under the normal living environment and it was suspected that parafunctional habits may be associated with the occurrence patterns of MMA during daytime.

  15. Increasing Elbow Torque Output of Stroke Patients by EMG-Controlled External Torque

    DTIC Science & Technology

    2007-11-02

    Abstract- A control algorithm for using homogenic EMG to control external assisting torque is developed for improving the elbow capability of...sacrificing performance. Keywords - Elbow , EMG, assisting torque, stroke I. INTRODUCTION Hemiparesis, which means partial loss of muscle strength...system to increase the total torque capability of the elbow for this class of patients. The system was controlled by surface EMG of biceps and

  16. Acute Improvement in Intraoperative EMG Following Common Fibular Nerve Decompression in Patients with Symptomatic Diabetic Sensorimotor Peripheral Neuropathy: 1. EMG Results.

    PubMed

    Anderson, James C; Nickerson, D Scott; Tracy, Brian L; Paxton, Roger J; Yamasaki, Dwayne S

    2017-09-01

    Background and Study Aims Electromyographic (EMG) recordings of the fibularis longus (FL) and tibialis anterior (TA) muscles were performed intraoperatively during common fibular nerve (CFN) nerve decompression (ND) in patients with symptomatic diabetic sensorimotor peripheral neuropathy (DSPN) and clinical nerve compression. Materials and Methods Forty-six legs in 40 patients underwent surgical ND by external neurolysis; FL and TA muscles were monitored intraoperatively. Evoked EMGs were recorded just prior to and within 1 minute after ND. Results Thirty-eight legs (82.6%) demonstrated EMG improvement 1 minute after ND. Sixty muscles (31 FL, 29 TA) were monitored, with 44 (73.3%) improving in EMG amplitude. Mean change in EMG amplitude represented a 73.6% improvement (p < 0.0001). Changes in EMG amplitudes correlated with visual analog scale pain improvement (p = 0.03). Conclusion This is the first report of acute changes in objective EMG responses during ND of CFN in DSPN patients and demonstrates that patients with symptomatic DSPN and clinical nerve entrapment have latent but functional axons that surgical ND can improve immediately. Georg Thieme Verlag KG Stuttgart · New York.

  17. Changes in jaw muscle EMG activity and pain after third molar surgery.

    PubMed

    Ernberg, M; Schopka, J H; Fougeront, N; Svensson, P

    2007-01-01

    Limited jaw-opening capacity is frequently encountered following third molar surgery and may impair function. The aim of this study was to investigate the electromyographic (EMG) activity in jaw muscles after third molar surgery to obtain more insight into the mechanisms of restrictions in jaw opening. Twenty subjects were examined before, 24 h and 1 week after surgery. Ten healthy controls were subjected to the same examination at two different occasions for intersession variability. The EMG activity of the masseter and anterior digastricus muscles was recorded at different jaw positions and during maximum voluntary clenching. Pain intensity was assessed at rest and during movements. The EMG activity in the jaw muscles increased with opening level (P < 0.01), but did not change after surgery. In contrast, the EMG activity during clenching was decreased in all muscles after surgery (P < 0.05). The pain intensity after surgery increased with jaw opening level (P < 0.001), but was in general not correlated to EMG level. Pain intensity during clenching was increased after surgery (P < 0.001), but not correlated to EMG level. The EMG activity did not change between visits in the control group. In conclusion, the results indicate that third molar surgery does not influence the EMG activity in the masseter and anterior digastricus muscles during various levels of static jaw opening, but decreases the EMG activity during clenching. However, these changes are not influenced by pain intensity. The results have implications for the understanding of the phenomenon of trismus.

  18. Word length effects on EMG/vowel duration relationships in apraxic speakers.

    PubMed

    Strauss, M; Klich, R J

    2001-01-01

    The effects of word length on the timing of lip electromyographic (EMG) activity for production of the vowel /u/ and the relationship of this activity to vowel duration were examined in matched male and female pairs of normal and apraxic speakers. Both apraxic speakers had suffered left cerebrovascular accidents, which resulted in apraxia of speech as the primary communication deficit. For all participants, the interval of time in which lip muscle activity was present prior to the onset of voicing for the /u/ (EMG onset interval) in each word systematically decreased as word length increased. However, EMG activity offset intervals, which were measured from the onset of voicing for /u/ to the onset of the reduction of EMG activity during the vowel (EMG termination interval), decreased as word length increased only for the normal speakers. Relative onset of EMG activity was not significantly related to relative offset of EMG activity or relative vowel duration. However, the relative EMG onset interval was correlated with the duration of an entire word. Findings for the relative EMG termination interval were variable and are discussed relative to the severity of apraxia of speech.

  19. Blind separation of convolutive sEMG mixtures based on independent vector analysis

    NASA Astrophysics Data System (ADS)

    Wang, Xiaomei; Guo, Yina; Tian, Wenyan

    2015-12-01

    An independent vector analysis (IVA) method base on variable-step gradient algorithm is proposed in this paper. According to the sEMG physiological properties, the IVA model is applied to the frequency-domain separation of convolutive sEMG mixtures to extract motor unit action potentials information of sEMG signals. The decomposition capability of proposed method is compared to the one of independent component analysis (ICA), and experimental results show the variable-step gradient IVA method outperforms ICA in blind separation of convolutive sEMG mixtures.

  20. EMG synchrony to assess impaired corticomotor control of locomotion after stroke.

    PubMed

    Lodha, Neha; Chen, Yen-Ting; McGuirk, Theresa E; Fox, Emily J; Kautz, Steven A; Christou, Evangelos A; Clark, David J

    2017-09-01

    Adapting one's gait pattern requires a contribution from cortical motor commands. Evidence suggests that frequency-based analysis of electromyography (EMG) can be used to detect this cortical contribution. Specifically, increased EMG synchrony between synergistic muscles in the Piper frequency band has been linked to heightened corticomotor contribution to EMG. Stroke-related damage to cerebral motor pathways would be expected to diminish EMG Piper synchrony. The objective of this study is therefore to test the hypothesis that EMG Piper synchrony is diminished in the paretic leg relative to nonparetic and control legs, particularly during a long-step task of walking adaptability. Twenty adults with post-stroke hemiparesis and seventeen healthy controls participated in this study. EMG Piper synchrony increased more for the control legs compare to the paretic legs when taking a non-paretic long step (5.02±3.22% versus 0.86±2.62%), p<0.01) and when taking a paretic long step (2.04±1.98% versus 0.70±2.34%, p<0.05). A similar but non-significant trend was evident when comparing non-paretic and paretic legs. No statistically significant differences in EMG Piper synchrony were found between legs for typical walking. EMG Piper synchrony was positively associated with walking speed and step length within the stroke group. These findings support the assertion that EMG Piper synchrony indicates corticomotor contribution to walking. Published by Elsevier Ltd.

  1. [The usage of E.M.G. in the dental research and the clinical practice].

    PubMed

    Droukas, B; Antoniou, D

    1989-01-01

    The first part of this review, refers to the use of electromyography (EMG) in studying the stomatognathic system. EMG is used for the study of function and fatigue of the masticatory muscles, the recording of centric relation etc. The behavior of the masticatory muscles (especially of the masseter and the temporalis) in the cases of TMJ dysfunction are also reviewed. In the second part, there is a description of the use of EMG biofeedback in the treatment of TMJ dysfunction, myofacial pain and bruxism. Finally, there is reference to the portable modular EMG biofeedback units.

  2. Effect of Selective Muscle Training Using Visual EMG Biofeedback on Infraspinatus and Posterior Deltoid

    PubMed Central

    Lim, One-bin; Kim, Jeong-ah; Song, Si-jeong; Cynn, Heon-seock; Yi, Chung-hwi

    2014-01-01

    We investigated the effects of visual electromyography (EMG) biofeedback during side-lying shoulder external rotation exercise on the EMG amplitude for the posterior deltoid, infraspinatus, and infraspinatus/posterior deltoid EMG activity ratio. Thirty-one asymptomatic subjects were included. Subjects performed side-lying shoulder external rotation exercise with and without visual EMG biofeedback. Surface EMG was used to collect data from the posterior deltoid and infraspinatus muscles. The visual EMG biofeedback applied the pre-established threshold to prevent excessive posterior deltoid muscle contraction. A paired t-test was used to determine the significance of the measurements between without vs. with visual EMG biofeedback. Posterior deltoid activity significantly decreased while infraspinatus activity and the infraspinatus/posterior activity ratio significantly increased during side-lying shoulder external rotation exercise with visual EMG biofeedback. This suggests that using visual EMG biofeedback during shoulder external rotation exercise is a clinically effective training method for reducing posterior deltoid activity and increasing infraspinatus activity. PMID:25713668

  3. Acute Exposure to Stress Improves Performance in Trace Eyeblink Conditioning and Spatial Learning Tasks in Healthy Men

    ERIC Educational Resources Information Center

    Duncko, Roman; Cornwell, Brian; Cui, Lihong; Merikangas, Kathleen R.; Grillon, Christian

    2007-01-01

    The present study investigated the effects of acute stress exposure on learning performance in humans using analogs of two paradigms frequently used in animals. Healthy male participants were exposed to the cold pressor test (CPT) procedure, i.e., insertion of the dominant hand into ice water for 60 sec. Following the CPT or the control procedure,…

  4. Cerebellar Norepinephrine Modulates Learning of Delay Classical Eyeblink Conditioning: Evidence for Post-Synaptic Signaling via PKA

    ERIC Educational Resources Information Center

    Fister, Mathew; Bickford, Paula C.; Cartford, M. Claire; Samec, Amy

    2004-01-01

    The neurotransmitter norepinephrine (NE) has been shown to modulate cerebellar-dependent learning and memory. Lesions of the nucleus locus coeruleus or systemic blockade of noradrenergic receptors has been shown to delay the acquisition of several cerebellar-dependent learning tasks. To date, no studies have shown a direct involvement of…

  5. Acute Exposure to Stress Improves Performance in Trace Eyeblink Conditioning and Spatial Learning Tasks in Healthy Men

    ERIC Educational Resources Information Center

    Duncko, Roman; Cornwell, Brian; Cui, Lihong; Merikangas, Kathleen R.; Grillon, Christian

    2007-01-01

    The present study investigated the effects of acute stress exposure on learning performance in humans using analogs of two paradigms frequently used in animals. Healthy male participants were exposed to the cold pressor test (CPT) procedure, i.e., insertion of the dominant hand into ice water for 60 sec. Following the CPT or the control procedure,…

  6. Neuroscience and Learning: Lessons from Studying the Involvement of a Region of Cerebellar Cortex in Eyeblink Classical Conditioning

    ERIC Educational Resources Information Center

    Villarreal, Ronald P.; Steinmetz, Joseph E.

    2005-01-01

    How the nervous system encodes learning and memory processes has interested researchers for 100 years. Over this span of time, a number of basic neuroscience methods has been developed to explore the relationship between learning and the brain, including brain lesion, stimulation, pharmacology, anatomy, imaging, and recording techniques. In this…

  7. Cerebellar Norepinephrine Modulates Learning of Delay Classical Eyeblink Conditioning: Evidence for Post-Synaptic Signaling via PKA

    ERIC Educational Resources Information Center

    Fister, Mathew; Bickford, Paula C.; Cartford, M. Claire; Samec, Amy

    2004-01-01

    The neurotransmitter norepinephrine (NE) has been shown to modulate cerebellar-dependent learning and memory. Lesions of the nucleus locus coeruleus or systemic blockade of noradrenergic receptors has been shown to delay the acquisition of several cerebellar-dependent learning tasks. To date, no studies have shown a direct involvement of…

  8. Neuroscience and Learning: Lessons from Studying the Involvement of a Region of Cerebellar Cortex in Eyeblink Classical Conditioning

    ERIC Educational Resources Information Center

    Villarreal, Ronald P.; Steinmetz, Joseph E.

    2005-01-01

    How the nervous system encodes learning and memory processes has interested researchers for 100 years. Over this span of time, a number of basic neuroscience methods has been developed to explore the relationship between learning and the brain, including brain lesion, stimulation, pharmacology, anatomy, imaging, and recording techniques. In this…

  9. Walking after partial paralysis assisted with EMG-triggered or switch-triggered functional electrical stimulation--two case studies.

    PubMed

    Dutta, Anirban; Kobetic, Rudi; Triolo, Ronald

    2011-01-01

    Functional Electrical Stimulation (FES) facilitates walking after paralysis by activating the muscles of the lower extremities. The FES-assisted stepping triggered either by a manual switch (switch-trigger), or by an electromyogram-based gait event detector (EMG-trigger) were presented in random order to two subjects with incomplete spinal cord injuries (iSCI) during ten trials over two alternate days. Subject iSCI-1 (C6 ASIA C) was non-ambulatory without the assistance of FES and could stand but not initiate a step volitionally. Subject iSCI-2 (T1 ASIA D) could walk only short distances with great difficulty without FES. Gait kinematics and kinetics were captured during FES-assisted over-ground walking with a rolling walker under laboratory conditions. Gait parameters including speed, left and right step length, left and right double support duration, left and right swing phase durations were extracted from the kinematic data. Mean, standard deviation, coefficient of variation, and 95% confidence interval were computed for each gait parameter under each triggering condition. The ground reaction forces were recorded for both the subjects while upper body support provided by the instrumented walker was recorded for iSCI-2. One way analysis of variance (ANOVA) was performed to determine whether significant differences existed in gait parameters between command sources. The left and right double support duration were significantly lower (p<0.05) during EMG-triggered gait than switch-triggered for iSCI-1. The average normal ground reaction force was significantly (p<0.05) higher during EMG-triggered gait than switch-triggered for iSCI-1 and iSCI-2. The average body weight support on the walker was significantly lower for EMG-triggered gait than switch-triggered one for iSCI-2. The results suggest that less user effort was needed when walking with EMG-triggered stepping than with manual switch trigger. © 2011 IEEE

  10. Quadratus femoris: An EMG investigation during walking and running.

    PubMed

    Semciw, Adam I; Freeman, Michael; Kunstler, Breanne E; Mendis, M Dilani; Pizzari, Tania

    2015-09-18

    Dysfunction of hip stabilizing muscles such as quadratus femoris (QF) is identified as a potential source of lower extremity injury during functional tasks like running. Despite these assumptions, there are currently no electromyography (EMG) data that establish the burst activity profile of QF during any functional task like walking or running. The objectives of this study were to characterize and compare the EMG activity profile of QF while walking and running (primary aim) and describe the direction specific action of QF (secondary aim). A bipolar fine-wire intramuscular electrode was inserted via ultrasound guidance into the QF of 10 healthy participants (4 females). Ensemble curves were generated from four walking and running trials, and normalized to maximum voluntary isometric contractions (MVICs). Paired t-tests compared the temporal and amplitude EMG variables. The relative activity of QF in the MVICs was calculated. The QF displayed moderate to high amplitude activity in the stance phase of walking and very high activity during stance in running. During swing, there was minimal QF activity recorded during walking and high amplitudes were present while running (run vs walk effect size=4.23, P<0.001). For the MVICs, external rotation and clam produced the greatest QF activity, with the hip in the anatomical position. This study provides an understanding of the activity demands placed on QF while walking and running. The high activity in late swing during running may signify a synergistic role with other posterior thigh muscles to control deceleration of the limb in preparation for stance.

  11. EMG in rotation-flexion of the torso.

    PubMed

    Kumar, Shrawan

    2010-12-01

    The objective of this study was to determine the magnitude and phasic relationship of the torso muscles in rotation-flexion of varying degree of asymmetries of the trunk. Nineteen normal young subjects (7 males and 12 females) were stabilized on a posture stabilizing platform and instructed to assume a flexed and right rotated posture. A combination 20°, 40° and 60° of rotation and 20°, 40° and 60° of flexion resulted in nine postures. These postures were assumed in a random order. The subjects were asked to exert their maximal voluntary isometric contraction (MVC) in the plane of rotation of the posture assumed for a period of 5s. The surface EMG from the external and internal obliques, rectus abdominis, latissimus dorsi and erector spinae at the 10th thoracic and 3rd lumbar vertebral levels was recorded. The abdominal muscles had the least response at 40° of flexion, the dorsal muscles had the highest magnitude. With increasing right rotation, the left external oblique continued to decrease its activity. The ANOVA revealed that rotation and muscles had a significant main effect on normalized peak EMG (p<0.02) in both genders. There was a significant interaction between rotation and flexion in both genders (p<0.02) and rotation and muscle in females. The erector spinae activity was highest at 40° flexion, due to greater mechanical disadvantage and having not reached the state of flexion-relaxation. The abdominal muscle activity declined with increasing asymmetry, due to the decreasing initial muscle length. The EMG activity was significantly affected by rotation than flexion (p<0.02). Copyright © 2010 Elsevier Ltd. All rights reserved.

  12. Evaluation of Linear Regression Simultaneous Myoelectric Control Using Intramuscular EMG.

    PubMed

    Smith, Lauren H; Kuiken, Todd A; Hargrove, Levi J

    2016-04-01

    The objective of this study was to evaluate the ability of linear regression models to decode patterns of muscle coactivation from intramuscular electromyogram (EMG) and provide simultaneous myoelectric control of a virtual 3-DOF wrist/hand system. Performance was compared to the simultaneous control of conventional myoelectric prosthesis methods using intramuscular EMG (parallel dual-site control)-an approach that requires users to independently modulate individual muscles in the residual limb, which can be challenging for amputees. Linear regression control was evaluated in eight able-bodied subjects during a virtual Fitts' law task and was compared to performance of eight subjects using parallel dual-site control. An offline analysis also evaluated how different types of training data affected prediction accuracy of linear regression control. The two control systems demonstrated similar overall performance; however, the linear regression method demonstrated improved performance for targets requiring use of all three DOFs, whereas parallel dual-site control demonstrated improved performance for targets that required use of only one DOF. Subjects using linear regression control could more easily activate multiple DOFs simultaneously, but often experienced unintended movements when trying to isolate individual DOFs. Offline analyses also suggested that the method used to train linear regression systems may influence controllability. Linear regression myoelectric control using intramuscular EMG provided an alternative to parallel dual-site control for 3-DOF simultaneous control at the wrist and hand. The two methods demonstrated different strengths in controllability, highlighting the tradeoff between providing simultaneous control and the ability to isolate individual DOFs when desired.

  13. Subauditory Speech Recognition based on EMG/EPG Signals

    NASA Technical Reports Server (NTRS)

    Jorgensen, Charles; Lee, Diana Dee; Agabon, Shane; Lau, Sonie (Technical Monitor)

    2003-01-01

    Sub-vocal electromyogram/electro palatogram (EMG/EPG) signal classification is demonstrated as a method for silent speech recognition. Recorded electrode signals from the larynx and sublingual areas below the jaw are noise filtered and transformed into features using complex dual quad tree wavelet transforms. Feature sets for six sub-vocally pronounced words are trained using a trust region scaled conjugate gradient neural network. Real time signals for previously unseen patterns are classified into categories suitable for primitive control of graphic objects. Feature construction, recognition accuracy and an approach for extension of the technique to a variety of real world application areas are presented.

  14. Further observations on the relationship of EMG and muscle force

    NASA Technical Reports Server (NTRS)

    Agarwal, G. C.; Cecchini, L. R.; Gottlieb, G. L.

    1972-01-01

    Human skeletal muscle may be regarded as an electro-mechanical transducer. Its physiological input is a neural signal originating at the alpha motoneurons in the spinal cord and its output is force and muscle contraction, these both being dependent on the external load. Some experimental data taken during voluntary efforts around the ankle joint and by direct electrical stimulation of the nerve are described. Some of these experiments are simulated by an analog model, the input of which is recorded physiological soleus muscle EMG. The output is simulated foot torque. Limitations of a linear model and effect of some nonlinearities are discussed.

  15. Application of singular spectrum-based change-point analysis to EMG-onset detection.

    PubMed

    Vaisman, Lev; Zariffa, José; Popovic, Milos R

    2010-08-01

    While many approaches have been proposed to identify the signal onset in EMG recordings, there is no standardized method for performing this task. Here, we propose to use a change-point detection procedure based on singular spectrum analysis to determine the onset of EMG signals. This method is suitable for automated real-time implementation, can be applied directly to the raw signal, and does not require any prior knowledge of the EMG signal's properties. The algorithm proposed by Moskvina and Zhigljavsky (2003) was applied to EMG segments recorded from wrist and trunk muscles. Wrist EMG data was collected from 9 Parkinson's disease patients with and without tremor, while trunk EMG data was collected from 13 healthy able-bodied individuals. Along with the change-point detection analysis, two threshold-based onset detection methods were applied, as well as visual estimates of the EMG onset by trained practitioners. In the case of wrist EMG data without tremor, the change-point analysis showed comparable or superior frequency and quality of detection results, as compared to other automatic detection methods. In the case of wrist EMG data with tremor and trunk EMG data, performance suffered because other changes occurring in these signals caused larger changes in the detection statistic than the changes caused by the initial muscle activation, suggesting that additional criteria are needed to identify the onset from the detection statistic other than its magnitude alone. Once this issue is resolved, change-point detection should provide an effective EMG-onset detection method suitable for automated real-time implementation.

  16. Embodying approach motivation: body posture influences startle eyeblink and event-related potential responses to appetitive stimuli.

    PubMed

    Price, Tom F; Dieckman, Laurtiz W; Harmon-Jones, Eddie

    2012-07-01

    Past research suggested that the motivational significance of images influences reflexive and electrocortical responses to those images (Briggs and Martin, 2009; Gard et al., 2007; Schupp et al., 2004), with erotica often exerting the largest effects for appetitive pictures (Grillon and Baas, 2003; Weinberg and Hajcak, 2010). This research paradigm, however, compares responses to different types of images (e.g., erotica vs. exciting sports scenes). This past motivational interpretation, therefore, would be further supported by experiments wherein appetitive picture content is held constant and motivational states are manipulated with a different method. In the present experiment, we tested the hypothesis that changes in physical postures associated with approach motivation influences reflexive and electrocortical responses to appetitive stimuli. Past research has suggested that bodily manipulations (e.g., facial expressions) play a role in emotion- and motivation-related physiology (Ekman and Davidson, 1993; Levenson et al., 1990). Extending these results, leaning forward (associated with a heightened urge to approach stimuli) relative to reclining (associated with less of an urge to approach stimuli) caused participants to have smaller startle eyeblink responses during appetitive, but not neutral, picture viewing. Leaning relative to reclining also caused participants to have larger LPPs to appetitive but not neutral pictures, and influenced ERPs as early as 100ms into stimulus viewing. This evidence suggests that body postures associated with approach motivation causally influence basic reflexive and electrocortical reactions to appetitive emotive stimuli. Copyright © 2012 Elsevier B.V. All rights reserved.

  17. Intelligent analysis of EMG data for improving lifestyle.

    PubMed

    Donnelly, Mark; Davies, Richard; Nugent, Chris

    2005-01-01

    In the tragic situation when a person loses his or her hand, they are usually faced with only one option if they wish to regain a good level of mobility; learn to control an artificial hand. It has been suggested that our brain stores a "body map" of the different parts in our body. Thus, if a person loses a hand, their "body map" remains intact and produces phantom sensations that permit the person to feel like they still have their hand. Some discomfort is felt during these sensations; nevertheless, there is a positive side to them as they enable patients to control prosthetic replacements. Sensations experienced can be measured using a method known as Electromyography (EMG) and can be acquired and processed to control an artificial hand. This research involved the acquisition, analysis and classification of EMG signals through construction of a recording device and the development of classification models based on heuristic approaches and Artificial Intelligence classifiers based on Neural Networks to control artificial hands.

  18. Locomotor adaptation to a soleus EMG-controlled antagonistic exoskeleton.

    PubMed

    Gordon, Keith E; Kinnaird, Catherine R; Ferris, Daniel P

    2013-04-01

    Locomotor adaptation in humans is not well understood. To provide insight into the neural reorganization that occurs following a significant disruption to one's learned neuromuscular map relating a given motor command to its resulting muscular action, we tied the mechanical action of a robotic exoskeleton to the electromyography (EMG) profile of the soleus muscle during walking. The powered exoskeleton produced an ankle dorsiflexion torque proportional to soleus muscle recruitment thus limiting the soleus' plantar flexion torque capability. We hypothesized that neurologically intact subjects would alter muscle activation patterns in response to the antagonistic exoskeleton by decreasing soleus recruitment. Subjects practiced walking with the exoskeleton for two 30-min sessions. The initial response to the perturbation was to "fight" the resistive exoskeleton by increasing soleus activation. By the end of training, subjects had significantly reduced soleus recruitment resulting in a gait pattern with almost no ankle push-off. In addition, there was a trend for subjects to reduce gastrocnemius recruitment in proportion to the soleus even though only the soleus EMG was used to control the exoskeleton. The results from this study demonstrate the ability of the nervous system to recalibrate locomotor output in response to substantial changes in the mechanical output of the soleus muscle and associated sensory feedback. This study provides further evidence that the human locomotor system of intact individuals is highly flexible and able to adapt to achieve effective locomotion in response to a broad range of neuromuscular perturbations.

  19. Locomotor adaptation to a soleus EMG-controlled antagonistic exoskeleton

    PubMed Central

    Kinnaird, Catherine R.; Ferris, Daniel P.

    2013-01-01

    Locomotor adaptation in humans is not well understood. To provide insight into the neural reorganization that occurs following a significant disruption to one's learned neuromuscular map relating a given motor command to its resulting muscular action, we tied the mechanical action of a robotic exoskeleton to the electromyography (EMG) profile of the soleus muscle during walking. The powered exoskeleton produced an ankle dorsiflexion torque proportional to soleus muscle recruitment thus limiting the soleus' plantar flexion torque capability. We hypothesized that neurologically intact subjects would alter muscle activation patterns in response to the antagonistic exoskeleton by decreasing soleus recruitment. Subjects practiced walking with the exoskeleton for two 30-min sessions. The initial response to the perturbation was to “fight” the resistive exoskeleton by increasing soleus activation. By the end of training, subjects had significantly reduced soleus recruitment resulting in a gait pattern with almost no ankle push-off. In addition, there was a trend for subjects to reduce gastrocnemius recruitment in proportion to the soleus even though only the soleus EMG was used to control the exoskeleton. The results from this study demonstrate the ability of the nervous system to recalibrate locomotor output in response to substantial changes in the mechanical output of the soleus muscle and associated sensory feedback. This study provides further evidence that the human locomotor system of intact individuals is highly flexible and able to adapt to achieve effective locomotion in response to a broad range of neuromuscular perturbations. PMID:23307949

  20. The Movement- and Load-Dependent Differences in the EMG Patterns of the Human Arm Muscles during Two-Joint Movements (A Preliminary Study).

    PubMed

    Tomiak, Tomasz; Abramovych, Tetiana I; Gorkovenko, Andriy V; Vereshchaka, Inna V; Mishchenko, Viktor S; Dornowski, Marcin; Kostyukov, Alexander I

    2016-01-01

    Slow circular movements of the hand with a fixed wrist joint that were produced in a horizontal plane under visual guidance during conditions of action of the elastic load directed tangentially to the movement trajectory were studied. The positional dependencies of the averaged surface EMGs in the muscles of the elbow and shoulder joints were compared for four possible combinations in the directions of load and movements. The EMG intensities were largely correlated with the waves of the force moment computed for a corresponding joint in the framework of a simple geometrical model of the system: arm - experimental setup. At the same time, in some cases the averaged EMGs exit from the segments of the trajectory restricted by the force moment singular points (FMSPs), in which the moments exhibited altered signs. The EMG activities display clear differences for the eccentric and concentric zones of contraction that are separated by the joint angle singular points (JASPs), which present extreme at the joint angle traces. We assumed that the modeled patterns of FMSPs and JASPs may be applied for an analysis of the synergic interaction between the motor commands arriving at different muscles in arbitrary two-joint movements.

  1. Effects of attention and precision of exerted force on beta range EEG-EMG synchronization during a maintained motor contraction task.

    PubMed

    Kristeva-Feige, Rumyana; Fritsch, Christoph; Timmer, Jens; Lücking, Carl-Hermann

    2002-01-01

    The present study was aimed at investigating the effect of attention and precision level of exerted force on beta range EEG-EMG synchronization. We simultaneously recorded cortical electrical activity (EEG) in a bipolar manner from the contralateral sensorimotor areas and surface electromyographic (EMG) activity from the flexor digitorum superficialis muscle in 10 healthy subjects during a maintained motor contraction task at 8% of the maximal voluntary contraction (MVC) force level. The coherence between oscillatory processes in the EEG and EMG was calculated. Three different conditions were investigated: (i) performing the task with high precision (HP); (ii) performing the task with high precision and simultaneously performing a mental arithmetic task (HPAT), i.e. attention was divided between the motor task and the mental arithmetic task; and (iii) performing the task with low precision (LP). We have found that the amount of beta range EEG-EMG synchronization decreases below the 95% confidence level when attention is divided between the motor task and the mental arithmetic task. The results also show that the frequency of beta range synchronization is higher with a higher level of precision but still lies within the beta frequency range (15-30 Hz). The data indicate that beta range synchronization represents a state of the cortico-muscular network when attention is directed towards the motor task. The frequency of synchronization of this network is associated with, and possibly encodes, precision in force production.

  2. The Movement- and Load-Dependent Differences in the EMG Patterns of the Human Arm Muscles during Two-Joint Movements (A Preliminary Study)

    PubMed Central

    Tomiak, Tomasz; Abramovych, Tetiana I.; Gorkovenko, Andriy V.; Vereshchaka, Inna V.; Mishchenko, Viktor S.; Dornowski, Marcin; Kostyukov, Alexander I.

    2016-01-01

    Slow circular movements of the hand with a fixed wrist joint that were produced in a horizontal plane under visual guidance during conditions of action of the elastic load directed tangentially to the movement trajectory were studied. The positional dependencies of the averaged surface EMGs in the muscles of the elbow and shoulder joints were compared for four possible combinations in the directions of load and movements. The EMG intensities were largely correlated with the waves of the force moment computed for a corresponding joint in the framework of a simple geometrical model of the system: arm - experimental setup. At the same time, in some cases the averaged EMGs exit from the segments of the trajectory restricted by the force moment singular points (FMSPs), in which the moments exhibited altered signs. The EMG activities display clear differences for the eccentric and concentric zones of contraction that are separated by the joint angle singular points (JASPs), which present extreme at the joint angle traces. We assumed that the modeled patterns of FMSPs and JASPs may be applied for an analysis of the synergic interaction between the motor commands arriving at different muscles in arbitrary two-joint movements. PMID:27375496

  3. Use of antagonist muscle EMG in the assessment of neuromuscular health of the low back.

    PubMed

    Lee, Nakyung; Kang, Hwayeong; Shin, Gwanseob

    2015-04-24

    Non-specific low back pain (LBP) has been one of the most frequently occurring musculoskeletal problems. Impairment in the mechanical stability of the lumbar spine has been known to lower the safety margin of the spine musculature and can result in the occurrence of pain symptoms of the low back area. Previously, changes in spinal stability have been identified by investigating recruitment patterns of low back and abdominal muscles in laboratory experiments with controlled postures and physical activities that were hard to conduct in daily life. The main objective of this study was to explore the possibility of developing a reliable spine stability assessment method using surface electromyography (EMG) of the low back and abdominal muscles in common physical activities. Twenty asymptomatic young participants conducted normal walking, plank, and isometric back extension activities prior to and immediately after maintaining a 10-min static upper body deep flexion on a flat bed. EMG data of the erector spinae, external oblique, and rectus abdominals were collected bilaterally, and their mean normalized amplitude values were compared between before and after the static deep flexion. Changes in the amplitude and co-contraction ratio values were evaluated to understand how muscle recruitment patterns have changed after the static deep flexion. Mean normalized amplitude of antagonist muscles (erector spinae muscles while conducting plank; external oblique and rectus abdominal muscles while conducting isometric back extension) decreased significantly (P < 0.05) after the 10-min static deep flexion. Normalized amplitude of agonist muscles did not vary significantly after deep flexion. Results of this study suggest the possibility of using surface EMG in the evaluation of spinal stability and low back health status in simple exercise postures that can be done in non-laboratory settings. Specifically, amplitude of antagonist muscles was found to be more sensitive than

  4. The influence of high and low heeled shoes on EMG timing characteristics of the lumbar and hip extensor complex during trunk forward flexion and return task.

    PubMed

    Mika, Anna; Clark, Brian C; Oleksy, Łukasz

    2013-12-01

    Recent studies suggest that wearing high-heel shoes increases the risk of developing certain musculoskeletal pain conditions. In this study we sought to examine whether heel height alters lumbar and hip extensor muscle timing characteristics during a standardized trunk flexion task. Thirty-one young, healthy women (22-27 years; 168.6 ± 5.1 cm; 57.1 ± 11.8 kg) participated in this study. Lumbar erector spinae (ES), gluteus maximus (GM), and biceps femoris (BF) electromyographic (EMG) signals were recorded during a trunk flexion task where subjects were instructed to flex their trunk in the sagittal plane and then return to a neutral posture. The task was repeated under three footwear conditions: while wearing no footwear, while wearing shoes with 4-cm heels, and while wearing shoes with 10-cm heels. EMG onset and offset times, as well as EMG duration, were calculated for each muscle and compared across conditions. We observed a significantly earlier onset of the ES EMG activity (1.36 ± 0.61 vs. 1.56 ± 0.67 s), and significantly delayed onset of the GM EMG activity (1.72 ± 0.66 vs. 1.28 ± 0.58 s) during the flexion phase of movement in the 10-cm heeled compared to the no footwear condition. The GM muscle also exhibited an earlier offset time in the 10-cm heel condition compared to the no footwear condition during the flexion movement (2.57 ± 0.67 vs. 3.30 ± 0.61 s) as well as during the return from flexion movement phase (10.87 ± 0.58 vs. 11.69 ± 0.65 s). These alterations in timing characteristic resulted in an overall decrease in the EMG duration for the GM muscle during the flexion movement. The results of this study suggest that high-heels alter trunk and hip extensor muscle coordination patterns. These findings, when considered in combination with other recent findings on the biomechanical effects of wearing high-heels, raise concern about whether wearing high heels results in abnormal spine loading patterns and increases the

  5. Long-term surface EMG monitoring using K-means clustering and compressive sensing

    NASA Astrophysics Data System (ADS)

    Balouchestani, Mohammadreza; Krishnan, Sridhar

    2015-05-01

    In this work, we present an advanced K-means clustering algorithm based on Compressed Sensing theory (CS) in combination with the K-Singular Value Decomposition (K-SVD) method for Clustering of long-term recording of surface Electromyography (sEMG) signals. The long-term monitoring of sEMG signals aims at recording of the electrical activity produced by muscles which are very useful procedure for treatment and diagnostic purposes as well as for detection of various pathologies. The proposed algorithm is examined for three scenarios of sEMG signals including healthy person (sEMG-Healthy), a patient with myopathy (sEMG-Myopathy), and a patient with neuropathy (sEMG-Neuropathr), respectively. The proposed algorithm can easily scan large sEMG datasets of long-term sEMG recording. We test the proposed algorithm with Principal Component Analysis (PCA) and Linear Correlation Coefficient (LCC) dimensionality reduction methods. Then, the output of the proposed algorithm is fed to K-Nearest Neighbours (K-NN) and Probabilistic Neural Network (PNN) classifiers in order to calclute the clustering performance. The proposed algorithm achieves a classification accuracy of 99.22%. This ability allows reducing 17% of Average Classification Error (ACE), 9% of Training Error (TE), and 18% of Root Mean Square Error (RMSE). The proposed algorithm also reduces 14% clustering energy consumption compared to the existing K-Means clustering algorithm.

  6. Effect of Vibration Training on Anaerobic Power and Quardroceps Surface EMG in Long Jumpers

    ERIC Educational Resources Information Center

    Liu, Bin; Luo, Jiong

    2015-01-01

    Objective: To explore the anaerobic power and surface EMG (sEMG) of quardrocep muscle in lower extremities after single vibration training intervention. Methods: 8 excellent male long jumpers voluntarily participated in this study. Four intervention modes were devised, including high frequency high amplitude (HFHA,30Hz,6mm), low frequency low…

  7. Emg Amplitude Estimators Based on Probability Distribution for Muscle-Computer Interface

    NASA Astrophysics Data System (ADS)

    Phinyomark, Angkoon; Quaine, Franck; Laurillau, Yann; Thongpanja, Sirinee; Limsakul, Chusak; Phukpattaranont, Pornchai

    To develop an advanced muscle-computer interface (MCI) based on surface electromyography (EMG) signal, the amplitude estimations of muscle activities, i.e., root mean square (RMS) and mean absolute value (MAV) are widely used as a convenient and accurate input for a recognition system. Their classification performance is comparable to advanced and high computational time-scale methods, i.e., the wavelet transform. However, the signal-to-noise-ratio (SNR) performance of RMS and MAV depends on a probability density function (PDF) of EMG signals, i.e., Gaussian or Laplacian. The PDF of upper-limb motions associated with EMG signals is still not clear, especially for dynamic muscle contraction. In this paper, the EMG PDF is investigated based on surface EMG recorded during finger, hand, wrist and forearm motions. The results show that on average the experimental EMG PDF is closer to a Laplacian density, particularly for male subject and flexor muscle. For the amplitude estimation, MAV has a higher SNR, defined as the mean feature divided by its fluctuation, than RMS. Due to a same discrimination of RMS and MAV in feature space, MAV is recommended to be used as a suitable EMG amplitude estimator for EMG-based MCIs.

  8. Preliminary Investigation of EMG Biofeedback Induced Relaxation with a Preschool Aged Stutterer.

    ERIC Educational Resources Information Center

    St. Louis, Kenneth O.; And Others

    1982-01-01

    Using comparative speech tasks and EMG recordings to assess the potential of EMG biofeedback-assisted relaxation to reduce stuttering, a preschool child was able to reduce larynegeal tension but not without some difficulty. The small effect of the training was in the direction of less stuttering. (Author/CM)

  9. Agonist and Antagonist Muscle EMG Activity Pattern Changes with Skill Acquisition.

    ERIC Educational Resources Information Center

    Engelhorn, Richard

    1983-01-01

    Using electromyography (EMG), researchers studied changes in the control of biceps and triceps brachii muscles that occurred as women college students learned two elbow flexion tasks. Data on EMG activity, angular kinematics, training, and angular displacement were analyzed. (Author/PP)

  10. Surface Laplacian of scalp electrical signals and independent component analysis resolve EMG contamination of electroencephalogram.

    PubMed

    Fitzgibbon, S P; DeLosAngeles, D; Lewis, T W; Powers, D M W; Whitham, E M; Willoughby, J O; Pope, K J

    2015-09-01

    The serious impact of electromyogram (EMG) contamination of electroencephalogram (EEG) is well recognised. The objective of this research is to demonstrate that combining independent component analysis with the surface Laplacian can eliminate EMG contamination of the EEG, and to validate that this processing does not degrade expected neurogenic signals. The method involves sequential application of ICA, using a manual procedure to identify and discard EMG components, followed by the surface Laplacian. The extent of decontamination is quantified by comparing processed EEG with EMG-free data that was recorded during pharmacologically induced neuromuscular paralysis. The combination of the ICA procedure and the surface Laplacian, with a flexible spherical spline, results in a strong suppression of EMG contamination at all scalp sites and frequencies. Furthermore, the ICA and surface Laplacian procedure does not impair the detection of well-known, cerebral responses; alpha activity with eyes-closed; ERP components (N1, P2) in response to an auditory oddball task; and steady state responses to photic and auditory stimulation. Finally, more flexible spherical splines increase the suppression of EMG by the surface Laplacian. We postulate this is due to ICA enabling the removal of local muscle sources of EMG contamination and the Laplacian transform being insensitive to distant (postural) muscle EMG contamination.

  11. Can standard surface EMG processing parameters be used to estimate motor unit global firing rate?

    NASA Astrophysics Data System (ADS)

    Zhou, Ping; Zev Rymer, William

    2004-06-01

    The relations between motor unit global firing rates and established quantitative measures for processing the surface electromyogram (EMG) signals were explored using a simulation approach. Surface EMG signals were simulated using the reported properties of the first dorsal interosseous muscle in man, and the models were varied systematically, using several hypothetical relations between motor unit electrical and force output, and also using different motor unit firing rate strategies. The utility of using different EMG processing parameters to help estimate global motor unit firing rate was evaluated based on their relations to the number of motor unit action potentials (MUAPs) in the simulated surface EMG signals. Our results indicate that the relation between motor unit electrical and mechanical properties, and the motor unit firing rate scheme are all important factors determining the form of the relation between surface EMG amplitude and motor unit global firing rate. Conversely, these factors have less impact on the relations between turn or zero-crossing point counts and the number of MUAPs in surface EMG. We observed that the number of turn or zero-crossing points tends to saturate with the increase in the MUAP number in surface EMG, limiting the utility of these measures as estimates of MUAP number. The simulation results also indicate that the mean or median frequency of the surface EMG power spectrum is a poor indicator of the global motor unit firing rate.

  12. Spatial variation and inconsistency between estimates of onset of muscle activation from EMG and ultrasound.

    PubMed

    Dieterich, Angela V; Botter, Alberto; Vieira, Taian Martins; Peolsson, Anneli; Petzke, Frank; Davey, Paul; Falla, Deborah

    2017-02-08

    Delayed onset of muscle activation can be a descriptor of impaired motor control. Activation onset can be estimated from electromyography (EMG)-registered muscle excitation and from ultrasound-registered muscle motion, which enables non-invasive measurements in deep muscles. However, in voluntary activation, EMG- and ultrasound-detected activation onsets may not correspond. To evaluate this, ten healthy men performed isometric elbow flexion at 20% to 70% of their maximal force. Utilising a multi-channel electrode transparent to ultrasound, EMG and M(otion)-mode ultrasound were recorded simultaneously over the biceps brachii muscle. The time intervals between automated and visually estimated activation onsets were correlated with the regional variation of EMG and muscle motion onset, contraction level and speed. Automated and visual onsets indicated variable time intervals between EMG- and motion onset, median (interquartile range) 96 (121) ms and 48 (72) ms, respectively. In 17% (computed analysis) or 23% (visual analysis) of trials, motion onset was detected before local EMG onset. Multi-channel EMG and M-mode ultrasound revealed regional differences in activation onset, which decreased with higher contraction speed (Spearman ρ ≥ 0.45, P < 0.001). In voluntary activation the heterogeneous motor unit recruitment together with immediate motion transmission may explain the high variation of the time intervals between local EMG- and ultrasound-detected activation onset.

  13. Statistics of differential Lissajous EMG for normal occlusion and Class II malocclusion.

    PubMed

    Deguchi, T; Kumai, T; Garetto, L

    1994-01-01

    Differential Lissajous electromyography (DL-EMG), a method of representing the simultaneous EMG values of two paired muscles as a single, continuous figure, was used in chewing tests with a sample of Japanese women having normal occlusion compared with a like group of Japanese female adolescents, having Class II, Division 1 malocclusion. For the normal sample, the DL-EMG figures described by the coordinated activity of the bilateral temporal and masseter muscles during chewing gum mastication typically appeared as repetitions of loops. Statistical data were gathered on the total EMG voltages, and on the location, rotational direction, and orientations of the DL-EMG loops when graphed onto Cartesian coordinates. These data were compared with those taken from the Class II sample. Significant differences were observed in the latter group for the EMG voltage levels of the balancing-side masseter muscles. The DL-EMG figures of the Class II group also showed irregularities in the shapes, locations, rotational directions, and orientations of the loops, indicative of irregular masticatory patterns. These data suggest that with sufficient control of factors such as age and sex, electromyography and especially DL-EMG techniques can be useful for characterizing masticatory differences between various occlusal groups.

  14. An open and configurable embedded system for EMG pattern recognition implementation for artificial arms.

    PubMed

    Jun Liu; Fan Zhang; Huang, He Helen

    2014-01-01

    Pattern recognition (PR) based on electromyographic (EMG) signals has been developed for multifunctional artificial arms for decades. However, assessment of EMG PR control for daily prosthesis use is still limited. One of the major barriers is the lack of a portable and configurable embedded system to implement the EMG PR control. This paper aimed to design an open and configurable embedded system for EMG PR implementation so that researchers can easily modify and optimize the control algorithms upon our designed platform and test the EMG PR control outside of the lab environments. The open platform was built on an open source embedded Linux Operating System running a high-performance Gumstix board. Both the hardware and software system framework were openly designed. The system was highly flexible in terms of number of inputs/outputs and calibration interfaces used. Such flexibility enabled easy integration of our embedded system with different types of commercialized or prototypic artificial arms. Thus far, our system was portable for take-home use. Additionally, compared with previously reported embedded systems for EMG PR implementation, our system demonstrated improved processing efficiency and high system precision. Our long-term goals are (1) to develop a wearable and practical EMG PR-based control for multifunctional artificial arms, and (2) to quantify the benefits of EMG PR-based control over conventional myoelectric prosthesis control in a home setting.

  15. Spatial variation and inconsistency between estimates of onset of muscle activation from EMG and ultrasound

    PubMed Central

    Dieterich, Angela V.; Botter, Alberto; Vieira, Taian Martins; Peolsson, Anneli; Petzke, Frank; Davey, Paul; Falla, Deborah

    2017-01-01

    Delayed onset of muscle activation can be a descriptor of impaired motor control. Activation onset can be estimated from electromyography (EMG)-registered muscle excitation and from ultrasound-registered muscle motion, which enables non-invasive measurements in deep muscles. However, in voluntary activation, EMG- and ultrasound-detected activation onsets may not correspond. To evaluate this, ten healthy men performed isometric elbow flexion at 20% to 70% of their maximal force. Utilising a multi-channel electrode transparent to ultrasound, EMG and M(otion)-mode ultrasound were recorded simultaneously over the biceps brachii muscle. The time intervals between automated and visually estimated activation onsets were correlated with the regional variation of EMG and muscle motion onset, contraction level and speed. Automated and visual onsets indicated variable time intervals between EMG- and motion onset, median (interquartile range) 96 (121) ms and 48 (72) ms, respectively. In 17% (computed analysis) or 23% (visual analysis) of trials, motion onset was detected before local EMG onset. Multi-channel EMG and M-mode ultrasound revealed regional differences in activation onset, which decreased with higher contraction speed (Spearman ρ ≥ 0.45, P < 0.001). In voluntary activation the heterogeneous motor unit recruitment together with immediate motion transmission may explain the high variation of the time intervals between local EMG- and ultrasound-detected activation onset. PMID:28176821

  16. Body position effects on sternocleidomastoid and masseter EMG pattern activity in patients undergoing occlusal splint therapy.

    PubMed

    Ormeño, G; Miralles, R; Santander, H; Casassus, R; Ferrer, P; Palazzi, C; Moya, H

    1997-10-01

    This study was conducted in order to determine the effects of body position on electromyographic (EMG) activity of sternocleidomastoid and masseter muscles, in 15 patients with myogenic cranio-cervical-mandibular dysfunction undergoing occlusal splint therapy. EMG activity was recorded by placing surface electrodes on the sternocleidomastoid and masseter muscles (contralateral to the habitual sleeping side of each patient). EMG activity at rest and during swallowing of saliva and maximal voluntary clenching was recorded in the following body positions: standing, supine and lateral decubitus. In the sternocleidomastoid muscle significant higher EMG activities at rest and during swallowing were recorded in the lateral decubitus position, whereas during maximal voluntary clenching EMG activity did not change. In the masseter muscle significant higher EMG activity during maximal voluntary clenching in a standing position was observed, whereas EMG activity at rest and during swallowing did not change. The opposite pattern of EMG activity supports the idea that there may exist a differential modulation of the motor neuron pools of the sternocleidomastoid and masseter muscles, of peripheral and/or central origin. This suggests that the presence of parafunctional habits and body position could be closely correlated with the clinical symptomatology in these muscles in patients with myogenic craniomandibular dysfunction.

  17. Basic reporting and interpretation of surface EMG amplitude and mean power frequency: a reply to Vitgotsky, Ogborn, and Phillips.

    PubMed

    Jenkins, Nathaniel D M; Housh, Terry J; Bergstrom, Haley C; Cochrane, Kristen C; Hill, Ethan C; Smith, Cory M; Johnson, Glen O; Schmidt, Richard J; Cramer, Joel T

    2016-03-01

    In this response, we addressed the specific issues raised by Vigotsky et al. and clarified (1) our methods and adherence to electromyographic signal reporting standards, (2) our interpretation of EMG amplitude, and (3) our interpretation of EMG mean power frequency.

  18. EMGs Analysis of Lumbar, Pelvic and Leg Muscles in Leg Length Discrepancy Adolescents

    NASA Astrophysics Data System (ADS)

    Sotelo-Barroso, Fernando; Márquez-Gamiño, Sergio; Caudillo-Cisneros, Cipriana

    2004-09-01

    To evaluate differences in surface electromyography (EMGs) activity of lumbar, pelvic and leg muscles in adolescents with and without LLD. EMGs activity records were taken during rest and maximal isometric voluntary contractions (MIVC). Peak to peak amplitude (PPA), mean rectified voltage (MRV) and root mean square (RMS), were analyzed. Statistical differences between short and large sides of LLD adolescents, were found (p<0.05). Higher values occurred in shorter limb muscles. No significative differences were found between left and right legs of the control subjects. When EMGs values were compared between short and large sides of LLD subjects with ipsilateral sides of controls, selective, statistically different EMGs values were exhibited. It is suggested that adaptative behavior to secondary biomechanical and/or neural changes occurred, even when none clinical symptoms were reported. The observations were remarked by the absence of EMGs differences between right and left sides of control subjects.

  19. Hardware System for Real-Time EMG Signal Acquisition and Separation Processing during Electrical Stimulation.

    PubMed

    Hsueh, Ya-Hsin; Yin, Chieh; Chen, Yan-Hong

    2015-09-01

    The study aimed to develop a real-time electromyography (EMG) signal acquiring and processing device that can acquire signal during electrical stimulation. Since electrical stimulation output can affect EMG signal acquisition, to integrate the two elements into one system, EMG signal transmitting and processing method has to be modified. The whole system was designed in a user-friendly and flexible manner. For EMG signal processing, the system applied Altera Field Programmable Gate Array (FPGA) as the core to instantly process real-time hybrid EMG signal and output the isolated signal in a highly efficient way. The system used the power spectral density to evaluate the accuracy of signal processing, and the cross correlation showed that the delay of real-time processing was only 250 μs.

  20. Short latency hand movement classification based on surface EMG spectrogram with PCA.

    PubMed

    Xiaolong Zhai; Jelfs, Beth; Chan, Rosa H M; Chung Tin

    2016-08-01

    Hand gesture recognition from forearm surface electromyography (sEMG) is an active research field in the development of motor prosthesis. Studies have shown that classification accuracy and efficiency is highly dependent on the features extracted from the EMG. In this paper, we show that EMG spectrograms are a particularly effective feature for discriminating multiple classes of hand gesture when subjected to principal component analysis for dimensionality reduction. We tested our method on the Ninapro database which includes sEMG data (12 channels) of 40 subjects performing 50 different hand movements. Our results demonstrate improved classification accuracy (by ~10%) over purely time domain features for 50 different hand movements, including small finger movements and different levels of force exertion. Our method has also reduced the error rate (by ~12%) at the transition phase of gestures which could improve robustness of gesture recognition when continuous classification from sEMG is required.

  1. Correlation between EEG-EMG coherence during isometric contraction and its imaginary execution.

    PubMed

    Hashimoto, Yasunari; Ushiba, Junichi; Kimura, Akio; Liu, Meigen; Tomita, Yukata

    2010-01-01

    To assess the similarity between cortical activities observed during actual and imaginary motor tasks, we evaluated electroencephalography-electromyography (EEG-EMG) coherence during motor task execution (ME) and the same taskrelated EEG power increase (TRPI) during kinesthetic motor imagery (MI). EEGs recorded at the vertex and EMGs recorded at the right tibialis anterior muscle (TA) were analyzed in 13 healthy subjects. Subjects were requested to perform: (1) isometric TA contraction, (2) imagery of the same movement without overt motor behavior, and (3) rest without MI. The results show significant EEG-EMG coherence during ME, as well as TRPI during both ME and MI tasks within a similar 14-30 Hz band. The magnitude of EEG-EMG coherence and TRPI varied among the subjects. Intersubject analysis revealed a significant correlation between EEG-EMG coherence and TRPI. These results support the hypothesis that ME and MI tasks involve overlapping neural networks in the perirolandic cortical areas.

  2. EMG of the hip adductor muscles in six clinical examination tests.

    PubMed

    Lovell, Gregory A; Blanch, Peter D; Barnes, Christopher J

    2012-08-01

    To assess activation of muscles of hip adduction using EMG and force analysis during standard clinical tests, and compare athletes with and without a prior history of groin pain. Controlled laboratory study. 21 male athletes from an elite junior soccer program. Bilateral surface EMG recordings of the adductor magnus, adductor longus, gracilis and pectineus as well as a unilateral fine-wire EMG of the pectineus were made during isometric holds in six clinical examination tests. A load cell was used to measure force data. Test type was a significant factor in the EMG output for all four muscles (all muscles p < 0.01). EMG activation was highest in Hips 0 or Hips 45 for adductor magnus, adductor longus and gracilis. EMG activation for pectineus was highest in Hips 90. Injury history was a significant factor in the EMG output for the adductor longus (p < 0.05), pectineus (p < 0.01) and gracilis (p < 0.01) but not adductor magnus. For force data, clinical test type was a significant factor (p < 0.01) with Hips 0 being significantly stronger than Hips 45, Hips 90 and Side lay. BMI (body mass index) was a significant factor (p < 0.01) for producing a higher force. All other factors had no significant effect on the force outputs. Hip adduction strength assessment is best measured at hips 0 (which produced most force) or 45° flexion (which generally gave the highest EMG output). Muscle EMG varied significantly with clinical test position. Athletes with previous groin injury had a significant fall in some EMG outputs. Copyright © 2011 Elsevier Ltd. All rights reserved.

  3. Sex differences in learning processes of classical and operant conditioning

    PubMed Central

    Dalla, Christina; Shors, Tracey J.

    2009-01-01

    Males and females learn and remember differently at different times in their lives. These differences occur in most species, from invertebrates to humans. We review here sex differences as they occur in laboratory rodent species. We focus on classical and operant conditioning paradigms, including classical eyeblink conditioning, fear conditioning, active avoidance and conditioned taste aversion. Sex differences have been reported during acquisition, retention and extinction in most of these paradigms. In general, females perform better than males in the classical eyeblink conditioning, in fear-potentiated startle and in most operant conditioning tasks, such as the active avoidance test. However, in the classical fear conditioning paradigm, in certain lever-pressing paradigms and in the conditioned taste aversion males outperform females or are more resistant to extinction. Most sex differences in conditioning are dependent on organizational effects of gonadal hormones during early development of the brain, in addition to modulation by activational effects during puberty and adulthood. Critically, sex differences in performance account for some of the reported effects on learning and these are discussed throughout the review. Because so many mental disorders are more prevalent on one sex than the other, it is important to consider sex differences in learning when applying animal models of learning for these disorders. Finally, we discuss how sex differences in learning continue to alter the brain throughout the lifespan. Thus, sex differences in learning are not only mediated by sex differences in the brain, but also contribute to them. PMID:19272397

  4. Sex differences in learning processes of classical and operant conditioning.

    PubMed

    Dalla, Christina; Shors, Tracey J

    2009-05-25

    Males and females learn and remember differently at different times in their lives. These differences occur in most species, from invertebrates to humans. We review here sex differences as they occur in laboratory rodent species. We focus on classical and operant conditioning paradigms, including classical eyeblink conditioning, fear-conditioning, active avoidance and conditioned taste aversion. Sex differences have been reported during acquisition, retention and extinction in most of these paradigms. In general, females perform better than males in the classical eyeblink conditioning, in fear-potentiated startle and in most operant conditioning tasks, such as the active avoidance test. However, in the classical fear-conditioning paradigm, in certain lever-pressing paradigms and in the conditioned taste aversion, males outperform females or are more resistant to extinction. Most sex differences in conditioning are dependent on organizational effects of gonadal hormones during early development of the brain, in addition to modulation by activational effects during puberty and adulthood. Critically, sex differences in performance account for some of the reported effects on learning and these are discussed throughout the review. Because so many mental disorders are more prevalent in one sex than the other, it is important to consider sex differences in learning when applying animal models of learning for these disorders. Finally, we discuss how sex differences in learning continue to alter the brain throughout the lifespan. Thus, sex differences in learning are not only mediated by sex differences in the brain, but also contribute to them.

  5. Using State-Space Model with Regime Switching to Represent the Dynamics of Facial Electromyography (EMG) Data

    ERIC Educational Resources Information Center

    Yang, Manshu; Chow, Sy-Miin

    2010-01-01

    Facial electromyography (EMG) is a useful physiological measure for detecting subtle affective changes in real time. A time series of EMG data contains bursts of electrical activity that increase in magnitude when the pertinent facial muscles are activated. Whereas previous methods for detecting EMG activation are often based on deterministic or…

  6. To What Extent Is Mean EMG Frequency during Gait a Reflection of Functional Muscle Strength in Children with Cerebral Palsy?

    ERIC Educational Resources Information Center

    Van Gestel, L.; Wambacq, H.; Aertbelien, E.; Meyns, P.; Bruyninckx, H.; Bar-On, L.; Molenaers, G.; De Cock, P.; Desloovere, K.

    2012-01-01

    The aim of the current paper was to analyze the potential of the mean EMG frequency, recorded during 3D gait analysis (3DGA), for the evaluation of functional muscle strength in children with cerebral palsy (CP). As walking velocity is known to also influence EMG frequency, it was investigated to which extent the mean EMG frequency is a reflection…

  7. The Effects of Relaxation Instructions and EMG Biofeedback of Test Anxiety, General Anxiety, and Locus of Control.

    ERIC Educational Resources Information Center

    Reed, Michael; Saslow, Carol

    1980-01-01

    Brief relaxation instruction alone and instructions plus electromyographic (EMG) feedback produced significant decreases in general and test-specific anxiety. EMG feedback added little to the effectiveness of relaxation instructions and practice. Relaxation instruction without EMG biofeedback shifted subjects toward a more internal locus of…

  8. The Effects of Relaxation Instructions and EMG Biofeedback of Test Anxiety, General Anxiety, and Locus of Control.

    ERIC Educational Resources Information Center

    Reed, Michael; Saslow, Carol

    1980-01-01

    Brief relaxation instruction alone and instructions plus electromyographic (EMG) feedback produced significant decreases in general and test-specific anxiety. EMG feedback added little to the effectiveness of relaxation instructions and practice. Relaxation instruction without EMG biofeedback shifted subjects toward a more internal locus of…

  9. Using State-Space Model with Regime Switching to Represent the Dynamics of Facial Electromyography (EMG) Data

    ERIC Educational Resources Information Center

    Yang, Manshu; Chow, Sy-Miin

    2010-01-01

    Facial electromyography (EMG) is a useful physiological measure for detecting subtle affective changes in real time. A time series of EMG data contains bursts of electrical activity that increase in magnitude when the pertinent facial muscles are activated. Whereas previous methods for detecting EMG activation are often based on deterministic or…

  10. [Quantitative topographic characterization of the myoelectric activity distribution of the masseter muscle: mapping of spectral EMG parameters].

    PubMed

    Scholle, H C; Schumann, N P; Anders, C; Mey, E

    1992-09-01

    A new method for quantitative characterization of myoelectrical masseter activity distribution by mapping of spectral EMG-parameters is described. The surface electromyograms of M. masseter were monopolarly recorded (16 channels). On the basis of registered EMG intervals (512 ms) the spectral EMG power of several frequency bands was calculated (Fast Fourier Transformation). The spectral EMG parameters between the 16 electrode positions were estimated by linear interpolation (4-nearest neighbours algorithm). Afterwards the spectral EMG parameters were fitted in a grey-tone or colour scale with 10 intervals. The so obtained EMG activity maps ("EMG-Maps") permit a quantitative-topographic characterization of myoelectrical masseter activity during different functional load procedures. The frequency range which is to consider in masseter surface-EMG investigations encloses frequencies between 15 and 500 Hz. The topography of EMG activation pattern of M. masseter is only described in a comprehensive manner when the electrode array consists of 16 electrodes and more. During defined motor tasks like clenching with controlled forces the reproducibility of EMG-Maps which respect to the topography of EMG activity pattern is very high. The absolute values of spectral EMG power as well as power changes of selected band ranges during clenching correlate to the extent of chewing forces.

  11. To What Extent Is Mean EMG Frequency during Gait a Reflection of Functional Muscle Strength in Children with Cerebral Palsy?

    ERIC Educational Resources Information Center

    Van Gestel, L.; Wambacq, H.; Aertbelien, E.; Meyns, P.; Bruyninckx, H.; Bar-On, L.; Molenaers, G.; De Cock, P.; Desloovere, K.

    2012-01-01

    The aim of the current paper was to analyze the potential of the mean EMG frequency, recorded during 3D gait analysis (3DGA), for the evaluation of functional muscle strength in children with cerebral palsy (CP). As walking velocity is known to also influence EMG frequency, it was investigated to which extent the mean EMG frequency is a reflection…

  12. Sensory prediction or motor control? Application of marr-albus type models of cerebellar function to classical conditioning.

    PubMed

    Lepora, Nathan F; Porrill, John; Yeo, Christopher H; Dean, Paul

    2010-01-01

    Marr-Albus adaptive filter models of the cerebellum have been applied successfully to a range of sensory and motor control problems. Here we analyze their properties when applied to classical conditioning of the nictitating membrane response in rabbits. We consider a system-level model of eyeblink conditioning based on the anatomy of the eyeblink circuitry, comprising an adaptive filter model of the cerebellum, a comparator model of the inferior olive and a linear dynamic model of the nictitating membrane plant. To our knowledge, this is the first model that explicitly includes all these principal components, in particular the motor plant that is vital for shaping and timing the behavioral response. Model assumptions and parameters were systematically investigated to disambiguate basic computational capacities of the model from features requiring tuning of properties and parameter values. Without such tuning, the model robustly reproduced a range of behaviors related to sensory prediction, by displaying appropriate trial-level associative learning effects for both single and multiple stimuli, including blocking and conditioned inhibition. In contrast, successful reproduction of the real-time motor behavior depended on appropriate specification of the plant, cerebellum and comparator models. Although some of these properties appear consistent with the system biology, fundamental questions remain about how the biological parameters are chosen if the cerebellar microcircuit applies a common computation to many distinct behavioral tasks. It is possible that the response profiles in classical conditioning of the eyeblink depend upon operant contingencies that have previously prevailed, for example in naturally occurring avoidance movements.

  13. Beta-range EEG-EMG coherence with isometric compensation for increasing modulated low-level forces.

    PubMed

    Chakarov, Vihren; Naranjo, José Raúl; Schulte-Mönting, Jürgen; Omlor, Wolfgang; Huethe, Frank; Kristeva, Rumyana

    2009-08-01

    Corticomuscular synchronization has been shown to occur in beta (15-30 Hz) and gamma range (30-45 Hz) during isometric compensation of static and dynamic (periodically modulated) low-level forces, respectively. However, it is still unknown to what extent these synchronization processes in beta and gamma range are modified with increasing modulated force. We addressed this question by investigating the corticomuscular coherence (CMC) between the electroencephalogram (EEG) and electromyogram (EMG) from the first dorsal interosseus muscle (FDI) as well as the cortical and muscular spectral power during a visuomotor task where different levels of a dynamic (modulated) force were used. Seven healthy right-handed female subjects compensated dynamic forces at 8, 16, and 24% of the maximal voluntary contraction (MVC) isometrically with their right index finger. Under the three conditions investigated, we found a broad-band CMC comprising both beta and gamma range and peaking at approximately 22 Hz within the beta band. This broad-band coherence increased linearly with higher force level. A separate analysis of the gamma range CMC did not show significant modulation of the CMC by the force levels. EEG and EMG spectral power did not show any significant difference among the three force conditions. Our results favor the view that the function of beta range CMC is not specific for low-level static forces only. The sensorimotor system may resort to stronger and also broader beta-range CMC to generate stable corticospinal interaction during increased force level, as well as when compensating for dynamic modulated forces. This finding re-enforces the importance of the beta-range EEG-EMG coherence in sensorimotor integration.

  14. Prosthetic hand control using motion discrimination from EMG signals.

    PubMed

    Kurisu, Naoyuki; Tsujiuchi, Nobutaka; Koizumi, Takayuki

    2009-01-01

    In this report, we improve the motion discrimination method from electromyogram (EMG) for a prosthetic hand and propose prosthetic hand control. In the past, we proved that a motion discrimination method using conic models could discriminate three hand motions without the incorrect discriminations that the elbow motions cause. In this research, to increase discrimination accuracy of motion discrimination using conic models, we propose a feature extraction method using quadratic polynomials. Additionally, because many prosthetic hands using motion discrimination have constant motion speed that can't be controlled, we propose an angular velocity generation method using multiple regression models. We verified these methods by controlling the 3D hand model. In the experiment, the proposed method could discriminate five motions at a rate of above 90 percent without the incorrect discriminations that elbow motions cause. Moreover, the wrist joint angle of the 3D hand model could be controlled by standard variation of 3[deg] or less.

  15. Multijoint upper limb torque estimation from sEMG measurements.

    PubMed

    Bueno, Diana R; Montano, L

    2013-01-01

    Estimation of joint torques through musculoskeletal models and measurements of muscle activations can be used for real-time control of robotic devices for rehabilitation. Many works developed models for analytic one joint motion, but less are found that develop models for functional multijoint movements. In this work we develop a methodology for tuning and optimizing Hill-based EMG-driven models oriented to the force control of robotic exoskeletons for the upper limb, selecting the more suitable parameters to be optimized. The model is tuned from experimental data obtained from healthy people. The torques estimated by that model will serve as reference for force-based control of an exoskeleton for rehabilitation.

  16. A novel biometric authentication approach using ECG and EMG signals.

    PubMed

    Belgacem, Noureddine; Fournier, Régis; Nait-Ali, Amine; Bereksi-Reguig, Fethi

    2015-05-01

    Security biometrics is a secure alternative to traditional methods of identity verification of individuals, such as authentication systems based on user name and password. Recently, it has been found that the electrocardiogram (ECG) signal formed by five successive waves (P, Q, R, S and T) is unique to each individual. In fact, better than any other biometrics' measures, it delivers proof of subject's being alive as extra information which other biometrics cannot deliver. The main purpose of this work is to present a low-cost method for online acquisition and processing of ECG signals for person authentication and to study the possibility of providing additional information and retrieve personal data from an electrocardiogram signal to yield a reliable decision. This study explores the effectiveness of a novel biometric system resulting from the fusion of information and knowledge provided by ECG and EMG (Electromyogram) physiological recordings. It is shown that biometrics based on these ECG/EMG signals offers a novel way to robustly authenticate subjects. Five ECG databases (MIT-BIH, ST-T, NSR, PTB and ECG-ID) and several ECG signals collected in-house from volunteers were exploited. A palm-based ECG biometric system was developed where the signals are collected from the palm of the subject through a minimally intrusive one-lead ECG set-up. A total of 3750 ECG beats were used in this work. Feature extraction was performed on ECG signals using Fourier descriptors (spectral coefficients). Optimum-Path Forest classifier was used to calculate the degree of similarity between individuals. The obtained results from the proposed approach look promising for individuals' authentication.

  17. Cerebellar vermis contributes to the extinction of conditioned fear.

    PubMed

    Utz, A; Thürling, M; Ernst, T M; Hermann, A; Stark, R; Wolf, O T; Timmann, D; Merz, C J

    2015-09-14

    The cerebellum is known to contribute to the acquisition and retention of conditioned motor and emotional responses. Eyeblink conditioning and fear conditioning have been studied in greatest detail. Whereas a considerable number of studies have shown that the cerebellum is also involved in extinction of conditioned eyeblink responses, the likely contribution of the cerebellum to extinction of conditioned fear responses has largely been ignored. In the present study, we analyzed functional brain imaging data (fMRI) of previous work investigating extinction of conditioned fear in 32 young and healthy men, in which event-related fMRI analysis did not include the cerebellum. This dataset was analyzed using a spatial normalization method optimized for the cerebellum. During fear acquisition, an unpleasant electric shock (unconditioned stimulus; US) was paired with one of two pictures of geometrical figures (conditioned stimulus; CS+), while the other picture (CS-) was never paired with the US. During extinction, CS+ and CS- were presented without the US. During the acquisition phase, the fMRI signal related to the CS+ was significantly higher in hemispheric lobule VI in early compared to late acquisition (p<.05, permutation corrected). During the extinction phase, the fMRI signal related to the contrast CS+>CS- was significantly higher within the anterior vermis in early compared to late extinction (p<.05, permutation corrected). The present data show that the cerebellum is not only associated with the acquisition but also with the extinction of conditioned fear.

  18. FastICA peel-off for ECG interference removal from surface EMG.

    PubMed

    Chen, Maoqi; Zhang, Xu; Chen, Xiang; Zhu, Mingxing; Li, Guanglin; Zhou, Ping

    2016-06-13

    Multi-channel recording of surface electromyographyic (EMG) signals is very likely to be contaminated by electrocardiographic (ECG) interference, specifically when the surface electrode is placed on muscles close to the heart. A novel fast independent component analysis (FastICA) based peel-off method is presented to remove ECG interference contaminating multi-channel surface EMG signals. Although demonstrating spatial variability in waveform shape, the ECG interference in different channels shares the same firing instants. Utilizing the firing information estimated from FastICA, ECG interference can be separated from surface EMG by a "peel off" processing. The performance of the method was quantified with synthetic signals by combining a series of experimentally recorded "clean" surface EMG and "pure" ECG interference. It was demonstrated that the new method can remove ECG interference efficiently with little distortion to surface EMG amplitude and frequency. The proposed method was also validated using experimental surface EMG signals contaminated by ECG interference. The proposed FastICA peel-off method can be used as a new and practical solution to eliminating ECG interference from multichannel EMG recordings.

  19. Factors governing the form of the relation between muscle force and the EMG: a simulation study.

    PubMed

    Zhou, Ping; Rymer, William Zev

    2004-11-01

    The dependence of the form of the EMG-force relation on key motoneuron and muscle properties was explored using a simulation approach. Surface EMG signals and isometric forces were simulated using existing motoneuron pool, muscle force, and surface EMG models, based primarily on reported properties of the first dorsal interosseous (FDI) muscle in humans. Our simulation results indicate that the relation between electrical and mechanical properties of the individual motor unit level plays the dominant role in determining the overall EMG amplitude-force relation of the muscle, while the underlying motor unit firing rate strategy appears to be a less important factor. However, different motor unit firing rate strategies result in substantially different relations between counts of the numbers of motoneuron discharges and the isometric force. Our simulation results also show that EMG amplitude (estimated as the average rectified value) increases as a result of synchronous discharges of different motor units within the pool, but the magnitude of this increase is determined primarily by the action potential duration of the synchronized motor units. Furthermore, when the EMG effects are normalized to their maximum levels, motor unit synchrony does not exert significant effects on the form of the EMG-force relation, provided that the synchrony level is held similar at different excitation levels.

  20. The EEG correlates of the TMS-induced EMG silent period in humans.

    PubMed

    Farzan, Faranak; Barr, Mera S; Hoppenbrouwers, Sylco S; Fitzgerald, Paul B; Chen, Robert; Pascual-Leone, Alvaro; Daskalakis, Zafiris J

    2013-12-01

    Application of magnetic or electrical stimulation to the motor cortex can result in a period of electromyography (EMG) silence in a tonically active peripheral muscle. This period of EMG silence is referred to as the silent period (SP). The duration of SP shows intersubject variability and reflects the integrity of cortical and corticospinal pathways. A non-invasive technique for assessing the duration of SP is the combination of Transcranial Magnetic Stimulation (TMS) with EMG. Utilizing TMS-EMG, several studies have reported on the shortening or lengthening of SP in neuropsychiatric disorders such as schizophrenia, bipolar disorder, depression, obsessive compulsive disorder, epilepsy, Parkinson's disease, and stroke. However, cortical, corticospinal and peripheral components are difficult to disentangle from EMG alone. Here, we use the multimodal neuroimaging technique of TMS-EMG combined with concurrent electroencephalography (EEG) recording to further examine the cortical origin of SP and the cortical oscillatory activity that underlies SP genesis. We demonstrate that the duration of SP is related to the temporal characteristics of the cortical reactivity and the power of delta to alpha oscillations in both local and remote areas ipsilateral and contralateral to the stimulation site, and beta oscillations locally. We illustrate that, compared to EMG, the EEG indices of the SP provide additional information about the brain dynamics and propose that the EEG measures of SP may be used in future clinical and research investigations to more precisely delineate the mechanisms underlying inhibitory impairments.

  1. An EMG-CT method using multiple surface electrodes in the forearm.

    PubMed

    Nakajima, Yasuhiro; Keeratihattayakorn, Saran; Yoshinari, Satoshi; Tadano, Shigeru

    2014-12-01

    Electromyography computed tomography (EMG-CT) method is proposed for visualizing the individual muscle activities in the human forearm. An EMG conduction model was formulated for reverse-estimation of muscle activities using EMG signals obtained with multi surface electrodes. The optimization process was calculated using sequential quadratic programming by comparing the estimated EMG values from the model with the measured values. The individual muscle activities in the deep region were estimated and used to produce an EMG tomographic image. For validation of the method, isometric contractions of finger muscles were examined for three subjects, applying a flexion load (4.9, 7.4 and 9.8 N) to the proximal interphalangeal joint of the middle finger. EMG signals in the forearm were recorded during the tasks using multiple surface electrodes, which were bound around the subject's forearm. The EMG-CT method illustrates the distribution of muscle activities within the forearm. The change in amplitude and area of activated muscles can be observed. The normalized muscle activities of all three subjects appear to increase monotonically with increases in the load. Kinesiologically, this method was able to estimate individual muscle activation values and could provide a novel tool for studying hand function and development of an examination for evaluating rehabilitation.

  2. On the usability of intramuscular EMG for prosthetic control: a Fitts' Law approach.

    PubMed

    Kamavuako, Ernest N; Scheme, Erik J; Englehart, Kevin B

    2014-10-01

    Previous studies on intramuscular EMG based control used offline data analysis. The current study investigates the usability of intramuscular EMG in two degree-of-freedom using a Fitts' Law approach by combining classification and proportional control to perform a task, with real time feedback of user performance. Nine able-bodied subjects participated in the study. Intramuscular and surface EMG signals were recorded concurrently from the right forearm. Five performance metrics (Throughput,Path efficiency, Average Speed, Overshoot and Completion Rate) were used for quantification of usability. Intramuscular EMG based control performed significantly better than surface EMG for Path Efficiency (80.5±2.4% vs. 71.5±3.8%, P=0.004) and Overshoot (22.0±3.0% vs. 45.1±6.6%, P=0.01). No difference was found between Throughput and Completion Rate. However the Average Speed was significantly higher for surface (51.8±5.5%) than for intramuscular EMG (35.7±2.7%). The results obtained in this study imply that intramuscular EMG has great potential as control source for advanced myoelectric prosthetic devices.

  3. Knee joint angle affects EMG-force relationship in the vastus intermedius muscle.

    PubMed

    Saito, Akira; Akima, Hiroshi

    2013-12-01

    It is not understood how the knee joint angle affects the relationship between electromyography (EMG) and force of four individual quadriceps femoris (QF) muscles. The purpose of this study was to examine the effect of the knee joint angle on the EMG-force relationship of the four individual QF muscles, particularly the vastus intermedius (VI), during isometric knee extensions. Eleven healthy men performed 20-100% of maximal voluntary contraction (MVC) at knee joint angles of 90°, 120° and 150°. Surface EMG of the four QF synergists was recorded and normalized by the root mean square during MVC. The normalized EMG of the four QF synergists at a knee joint angle of 150° was significantly lower than that at 90° and 120° (P < 0.05). Comparing the normalized EMG among the four QF synergists, a significantly lower normalized EMG was observed in the VI at 150° as compared with the other three QF muscles (P < 0.05). These results suggest that the EMG-force relationship of the four QF synergists shifted downward at an extended knee joint angle of 150°. Furthermore, the neuromuscular activation of the VI was the most sensitive to change in muscle length among the four QF synergistic muscles. Copyright © 2013 Elsevier Ltd. All rights reserved.

  4. The EEG Correlates of the TMS Induced EMG Silent Period in Humans

    PubMed Central

    Farzan, Faranak; Barr, Mera S.; Hoppenbrouwers, Sylco S.; Fitzgerald, Paul B.; Chen, Robert; Pascual-Leone, Alvaro; Daskalakis, Zafiris J.

    2014-01-01

    Application of magnetic or electrical stimulation to the motor cortex can result in a period of electromyography (EMG) silence in a tonically active peripheral muscle. This period of EMG silence is referred to as the silent period (SP). The duration of SP shows intersubject variability and reflects the integrity of cortical and corticospinal pathways. A non-invasive technique for assessing the duration of SP is the combination of Transcranial Magnetic Stimulation (TMS) with EMG. Utilizing TMS-EMG, several studies have reported on the shortening or lengthening of SP in neuropsychiatric disorders such as schizophrenia, bipolar disorder, depression, obsessive compulsive disorder, epilepsy, Parkinson’s disease, and stroke. However, cortical, corticospinal and peripheral components are difficult to disentangle from EMG alone. Here, we use the multimodal neuroimaging technique of TMS-EMG combined with concurrent electroencephalography (EEG) recording to further examine the cortical origin of SP and the cortical oscillatory activity that underlies SP genesis. We demonstrate that the duration of SP is related to the temporal characteristics of the cortical reactivity and the power of delta to alpha oscillations in both local and remote areas ipsilateral and contralateral to the stimulation site, and beta oscillations locally. We illustrate that, compared to EMG, the EEG indices of the SP provide additional information about the brain dynamics and propose that the EEG measures of SP may be used in future clinical and research investigations to more precisely delineate the mechanisms underlying inhibitory impairments. PMID:23800790

  5. EMG feedback tasks reduce reflexive stiffness during force and position perturbations.

    PubMed

    Forbes, Patrick A; Happee, Riender; van der Helm, Frans C T; Schouten, Alfred C

    2011-08-01

    Force and position perturbations are widely applied to identify muscular and reflexive contributions to posture maintenance of the arm. Both task instruction (force vs. position) and the inherently linked perturbation type (i.e., force perturbations-position task and position perturbations-force tasks) affect these contributions and their mutual balance. The goal of this study is to explore the modulation of muscular and reflexive contributions in shoulder muscles using EMG biofeedback. The EMG biofeedback provides a harmonized task instruction to facilitate the investigation of perturbation type effects irrespective of task instruction. External continuous force and position perturbations with a bandwidth of 0.5-20 Hz were applied at the hand while subjects maintained prescribed constant levels of muscular co-activation using visual feedback of an EMG biofeedback signal. Joint admittance and reflexive impedance were identified in the frequency domain, and parametric identification separated intrinsic muscular and reflexive feedback properties. In tests with EMG biofeedback, perturbation type (position and force) had no effect on joint admittance and reflexive impedance, indicating task as the dominant factor. A reduction in muscular and reflexive stiffness was observed when performing the EMG biofeedback task relative to the position task. Reflexive position feedback was effectively suppressed during the equivalent EMG biofeedback task, while velocity and acceleration feedback were both decreased by approximately 37%. This indicates that force perturbations with position tasks are a more effective paradigm to investigate complete dynamic motor control of the arm, while EMG tasks tend to reduce the reflexive contribution.

  6. Parkinson's disease rigidity: EMG in a small hand muscle at "rest".

    PubMed

    Cantello, R; Gianelli, M; Civardi, C; Mutani, R

    1995-10-01

    The presence of excessive EMG at "rest" might be an important factor in the genesis of Parkinson's disease (PD) rigidity, and we studied it in the first dorsal interosseous muscle (FDI) of 8 idiopathic PD patients. We had 8 age- and sex-matched normal controls. In the PD group, the average area of the surface EMG at "rest" correlated significantly with the clinical evaluation of rigidity and remained abnormally enhanced for 10-15 min after a command to "relax." Later, it tended to decline, but its entity was still much greater than in controls. The EMG "at rest" consisted of unwilled motor unit (MU) firing. A larger MU number was recruited in patients than in controls at "rest." MU rate coding was similar in both groups. Eventually, patients could get periods of EMG silence which, however, were interrupted by short EMG bursts, even if there was no muscle stretch. These bursts were interpreted as residual fragments of the original excessive EMG at "rest." MUs first recruited during such bursts showed high, but not total, overlapping with those first recruited by a gentle voluntary contraction or by a weak transcranial magnetic stimulus to motor cortex. We conclude that EMG activity at "rest" was made up of the discharge of low-threshold MUs, with a recruitment order similar to that resulting from descending cortico-spinal volleys. However, we cannot exclude other possible input sources to the alpha-motoneurones at "rest."

  7. Back muscle EMG of helicopter pilots in flight: effects of fatigue, vibration, and posture.

    PubMed

    de Oliveira, Carlos Gomes; Nadal, Jurandir

    2004-04-01

    The high prevalence of low back pain in helicopter pilots has been attributed to back muscle fatigue due to a pilot's required posture and/or aircraft vibration. This study investigated the effect of posture and vibration on the surface electromyogram (EMG) of right and left erector spinae (ES) muscles of pilots and evaluated ES fatigue during flight. There were 12 male pilots who were monitored during helicopter flights lasting an average of 2 h. Prior to the flight, a maximal voluntary contraction (MVC) of ES was performed and the EMG was recorded. Vibration was measured at the pilot's seat through a triaxial accelerometer. The effect of posture on EMG was tested by comparing four characteristics of left and right EMG expressed as % MVC. Effect of Z vibration on EMG was investigated by coherence function and through correlation between coherently averaged EMG and Z for the frequencies of the main rotor of the helicopter (1R) and its first harmonic (2R). Fatigue was investigated through median frequencies (MF) of the EMG power spectra. No effect of posture on EMG was found for any parameter (p > 0.05). Data from one pilot suggested an effect of 1R on EMG, but statistical tests revealed this not to be significant (p > 0.05) for any pilot. No fatigue was evidenced by linear regression of MF. While the scientific literature contains the hypothesis that low back pain in helicopter pilots is mainly due to muscle fatigue caused by posture and/or vibration, the present study did not lend support to this hypothesis.

  8. Comparison of sEMG processing methods during whole-body vibration exercise.

    PubMed

    Lienhard, Karin; Cabasson, Aline; Meste, Olivier; Colson, Serge S

    2015-12-01

    The objective was to investigate the influence of surface electromyography (sEMG) processing methods on the quantification of muscle activity during whole-body vibration (WBV) exercises. sEMG activity was recorded while the participants performed squats on the platform with and without WBV. The spikes observed in the sEMG spectrum at the vibration frequency and its harmonics were deleted using state-of-the-art methods, i.e. (1) a band-stop filter, (2) a band-pass filter, and (3) spectral linear interpolation. The same filtering methods were applied on the sEMG during the no-vibration trial. The linear interpolation method showed the highest intraclass correlation coefficients (no vibration: 0.999, WBV: 0.757-0.979) with the comparison measure (unfiltered sEMG during the no-vibration trial), followed by the band-stop filter (no vibration: 0.929-0.975, WBV: 0.661-0.938). While both methods introduced a systematic bias (P < 0.001), the error increased with increasing mean values to a higher degree for the band-stop filter. After adjusting the sEMG(RMS) during WBV for the bias, the performance of the interpolation method and the band-stop filter was comparable. The band-pass filter was in poor agreement with the other methods (ICC: 0.207-0.697), unless the sEMG(RMS) was corrected for the bias (ICC ⩾ 0.931, %LOA ⩽ 32.3). In conclusion, spectral linear interpolation or a band-stop filter centered at the vibration frequency and its multiple harmonics should be applied to delete the artifacts in the sEMG signals during WBV. With the use of a band-stop filter it is recommended to correct the sEMG(RMS) for the bias as this procedure improved its performance.

  9. Masticatory Muscle Sleep Background EMG Activity is Elevated in Myofascial TMD Patients

    PubMed Central

    Raphael, Karen G.; Janal, Malvin N.; Sirois, David A.; Dubrovsky, Boris; Wigren, Pia E.; Klausner, Jack J.; Krieger, Ana C.; Lavigne, Gilles J.

    2013-01-01

    Despite theoretical speculation and strong clinical belief, recent research using laboratory polysomnographic (PSG) recording has provided new evidence that frequency of sleep bruxism (SB) masseter muscle events, including grinding or clenching of the teeth during sleep, is not increased for women with chronic myofascial temporomandibular disorder (TMD). The current case-control study compares a large sample of women suffering from chronic myofascial TMD (n=124) with a demographically matched control group without TMD (n=46) on sleep background electromyography (EMG) during a laboratory PSG study. Background EMG activity was measured as EMG root mean square (RMS) from the right masseter muscle after lights out. Sleep background EMG activity was defined as EMG RMS remaining after activity attributable to SB, other orofacial activity, other oromotor activity and movement artifacts were removed. Results indicated that median background EMG during these non SB-event periods was significantly higher (p<.01) for women with myofascial TMD (median=3.31 μV and mean=4.98 μV) than for control women (median=2.83 μV and mean=3.88 μV) with median activity in 72% of cases exceeding control activity. Moreover, for TMD cases, background EMG was positively associated and SB event-related EMG was negatively associated with pain intensity ratings (0–10 numerical scale) on post sleep waking. These data provide the foundation for a new focus on small, but persistent, elevations in sleep EMG activity over the course of the night as a mechanism of pain induction or maintenance. PMID:24237356

  10. Spatial variability of muscle activity during human walking: the effects of different EMG normalization approaches.

    PubMed

    Cronin, N J; Kumpulainen, S; Joutjärvi, T; Finni, T; Piitulainen, H

    2015-08-06

    Human leg muscles are often activated inhomogeneously, e.g. in standing. This may also occur in complex tasks like walking. Thus, bipolar surface electromyography (sEMG) may not accurately represent whole muscle activity. This study used 64-electrode high-density sEMG (HD-sEMG) to examine spatial variability of lateral gastrocnemius (LG) muscle activity during the stance phase of walking, maximal voluntary contractions (MVCs) and maximal M-waves, and determined the effects of different normalization approaches on spatial and inter-participant variability. Plantar flexion MVC, maximal electrically elicited M-waves and walking at self-selected speed were recorded in eight healthy males aged 24-34. sEMG signals were assessed in four ways: unnormalized, and normalized to MVC, M-wave or peak sEMG during the stance phase of walking. During walking, LG activity varied spatially, and was largest in the distal and lateral regions. Spatial variability fluctuated throughout the stance phase. Normalizing walking EMG signals to the peak value during stance reduced spatial variability within LG on average by 70%, and inter-participant variability by 67%. Normalizing to MVC reduced spatial variability by 17% but increased inter-participant variability by 230%. Normalizing to M-wave produced the greatest spatial variability (45% greater than unnormalized EMG) and increased inter-participant variability by 70%. Unnormalized bipolar LG sEMG may provide misleading results about representative muscle activity in walking due to spatial variability. For the peak value and MVC approaches, different electrode locations likely have minor effects on normalized results, whereas electrode location should be carefully considered when normalizing walking sEMG data to maximal M-waves. Copyright © 2015 IBRO. Published by Elsevier Ltd. All rights reserved.

  11. [sEMG Time-frequency analysis techniques for evaluation of muscle fatigue and it's application in ergonomic studies].

    PubMed

    Wang, Du-ming; Wang, Jian; Ge, Lie-zhong

    2003-10-01

    As a non-invasive on-line measurement, sEMG can reflect the status of muscle activity and muscle function accurately and objectively. Some sEMG Time-frequency analysis techniques, especially the JASA (joint analysis of EMG spectrum and amplitude) analysis, for evaluation of muscle fatigue in ergonomics and occupational field studies are introduced and evaluated in this paper. The sEMG signal analysis and the necessity for developing sEMG analysis techniques for field use in ergonomics are also briefly discussed.