Rapid Eye Movement Sleep Abnormalities in Children with Pediatric Acute-Onset Neuropsychiatric Syndrome (PANS)

PubMed Central

Gaughan, Thomas; Buckley, Ashura; Hommer, Rebecca; Grant, Paul; Williams, Kyle; Leckman, James F.; Swedo, Susan E.

2016-01-01

Study Objectives: Polysomnographic investigation of sleep architecture in children presenting with pediatric acute-onset neuropsychiatric syndrome (PANS). Methods: Fifteen consecutive subjects meeting criteria for PANS (mean age = 7.2 y; range 3–10 y) underwent single-night full polysomnography (PSG) read by a pediatric neurologist. Results: Thirteen of 15 subjects (87%) had abnormalities detected with PSG. Twelve of 15 had evidence of rapid eye movement (REM) sleep motor disinhibition, as characterized by excessive movement, laughing, hand stereotypies, moaning, or the continuation of periodic limb movements during sleep (PLMS) into REM sleep. Conclusions: This study shows various forms of REM sleep motor disinhibition present in a population of children with PANS. Citation: Gaughan T, Buckley A, Hommer R, Grant P; Williams K, Leckman JF, Swedo SE. Rapid eye movement sleep abnormalities in children with pediatric acute-onset neuropsychiatric syndrome (PANS). J Clin Sleep Med 2016;12(7):1027–1032. PMID:27166296

The Circadian Clock Gene Csnk1e Regulates Rapid Eye Movement Sleep Amount, and Nonrapid Eye Movement Sleep Architecture in Mice

PubMed Central

Zhou, Lili; Bryant, Camron D.; Loudon, Andrew; Palmer, Abraham A.; Vitaterna, Martha Hotz; Turek, Fred W.

2014-01-01

Study Objectives: Efforts to identify the genetic basis of mammalian sleep have included quantitative trait locus (QTL) mapping and gene targeting of known core circadian clock genes. We combined three different genetic approaches to identify and test a positional candidate sleep gene — the circadian gene casein kinase 1 epsilon (Csnk1e), which is located in a QTL we identified for rapid eye movement (REM) sleep on chromosome 15. Measurements and Results: Using electroencephalographic (EEG) and electromyographic (EMG) recordings, baseline sleep was examined in a 12-h light:12-h dark (LD 12:12) cycle in mice of seven genotypes, including Csnk1etau/tau and Csnk1e-/- mutant mice, Csnk1eB6.D2 and Csnk1eD2.B6 congenic mice, and their respective wild-type littermate control mice. Additionally, Csnk1etau/tau and wild-type mice were examined in constant darkness (DD). Csnk1etau/tau mutant mice and both Csnk1eB6.D2 and Csnk1eD2.B6 congenic mice showed significantly higher proportion of sleep time spent in REM sleep during the dark period than wild-type controls — the original phenotype for which the QTL on chromosome 15 was identified. This phenotype persisted in Csnk1etau/tau mice while under free-running DD conditions. Other sleep phenotypes observed in Csnk1etau/tau mice and congenics included a decreased number of bouts of nonrapid eye movement (NREM) sleep and an increased average NREM sleep bout duration. Conclusions: These results demonstrate a role for Csnk1e in regulating not only the timing of sleep, but also the REM sleep amount and NREM sleep architecture, and support Csnk1e as a causal gene in the sleep QTL on chromosome 15. Citation: Zhou L; Bryant CD; Loudon A; Palmer AA; Vitaterna MH; Turek FW. The circadian clock gene Csnk1e regulates rapid eye movement sleep amount, and nonrapid eye movement sleep architecture in mice. SLEEP 2014;37(4):785-793. PMID:24744456

Tonic and phasic phenomena underlying eye movements during sleep in the cat

PubMed Central

Márquez-Ruiz, Javier; Escudero, Miguel

2008-01-01

Mammalian sleep is not a homogenous state, and different variables have traditionally been used to distinguish different periods during sleep. Of these variables, eye movement is one of the most paradigmatic, and has been used to differentiate between the so-called rapid eye movement (REM) and non-REM (NREM) sleep periods. Despite this, eye movements during sleep are poorly understood, and the behaviour of the oculomotor system remains almost unknown. In the present work, we recorded binocular eye movements during the sleep–wake cycle of adult cats by the scleral search-coil technique. During alertness, eye movements consisted of conjugated saccades and eye fixations. During NREM sleep, eye movements were slow and mostly unconjugated. The two eyes moved upwardly and in the abducting direction, producing a tonic divergence and elevation of the visual axis. During the transition period between NREM and REM sleep, rapid monocular eye movements of low amplitude in the abducting direction occurred in coincidence with ponto-geniculo-occipital waves. Along REM sleep, the eyes tended to maintain a tonic convergence and depression, broken by high-frequency bursts of complex rapid eye movements. In the horizontal plane, each eye movement in the burst comprised two consecutive movements in opposite directions, which were more evident in the eye that performed the abducting movements. In the vertical plane, rapid eye movements were always upward. Comparisons of the characteristics of eye movements during the sleep–wake cycle reveal the uniqueness of eye movements during sleep, and the noteworthy existence of tonic and phasic phenomena in the oculomotor system, not observed until now. PMID:18499729

Tonic and phasic phenomena underlying eye movements during sleep in the cat.

PubMed

Márquez-Ruiz, Javier; Escudero, Miguel

2008-07-15

Mammalian sleep is not a homogenous state, and different variables have traditionally been used to distinguish different periods during sleep. Of these variables, eye movement is one of the most paradigmatic, and has been used to differentiate between the so-called rapid eye movement (REM) and non-REM (NREM) sleep periods. Despite this, eye movements during sleep are poorly understood, and the behaviour of the oculomotor system remains almost unknown. In the present work, we recorded binocular eye movements during the sleep-wake cycle of adult cats by the scleral search-coil technique. During alertness, eye movements consisted of conjugated saccades and eye fixations. During NREM sleep, eye movements were slow and mostly unconjugated. The two eyes moved upwardly and in the abducting direction, producing a tonic divergence and elevation of the visual axis. During the transition period between NREM and REM sleep, rapid monocular eye movements of low amplitude in the abducting direction occurred in coincidence with ponto-geniculo-occipital waves. Along REM sleep, the eyes tended to maintain a tonic convergence and depression, broken by high-frequency bursts of complex rapid eye movements. In the horizontal plane, each eye movement in the burst comprised two consecutive movements in opposite directions, which were more evident in the eye that performed the abducting movements. In the vertical plane, rapid eye movements were always upward. Comparisons of the characteristics of eye movements during the sleep-wake cycle reveal the uniqueness of eye movements during sleep, and the noteworthy existence of tonic and phasic phenomena in the oculomotor system, not observed until now.

The golden age of rapid eye movement sleep discoveries. 1. Lucretius--1964.

PubMed

Gottesmann, C

2001-10-01

Although there were several premonitory signs of a sleep stage with dreaming, it was only in 1953 that such a stage was identified with certainty. This paper analyses the observations and research related to this dreaming stage (rapid eye movement sleep) until 1964. During these 11 years of research, the main psychological and physiological characteristics of this sleep stage were first described. Where the few results or discussions were later questioned, today's current state of knowledge is briefly outlined.

Normal Morning Melanin-Concentrating Hormone Levels and No Association with Rapid Eye Movement or Non-Rapid Eye Movement Sleep Parameters in Narcolepsy Type 1 and Type 2.

PubMed

Schrölkamp, Maren; Jennum, Poul J; Gammeltoft, Steen; Holm, Anja; Kornum, Birgitte R; Knudsen, Stine

2017-02-15

Other than hypocretin-1 (HCRT-1) deficiency in narcolepsy type 1 (NT1), the neurochemical imbalance of NT1 and narcolepsy type 2 (NT2) with normal HCRT-1 levels is largely unknown. The neuropeptide melanin-concentrating hormone (MCH) is mainly secreted during sleep and is involved in rapid eye movement (REM) and non-rapid eye movement (NREM) sleep regulation. Hypocretin neurons reciprocally interact with MCH neurons. We hypothesized that altered MCH secretion contributes to the symptoms and sleep abnormalities of narcolepsy and that this is reflected in morning cerebrospinal fluid (CSF) MCH levels, in contrast to previously reported normal evening/afternoon levels. Lumbar CSF and plasma were collected from 07:00 to 10:00 from 57 patients with narcolepsy (subtypes: 47 NT1; 10 NT2) diagnosed according to International Classification of Sleep Disorders, Third Edition (ICSD-3) and 20 healthy controls. HCRT-1 and MCH levels were quantified by radioimmunoassay and correlated with clinical symptoms, polysomnography (PSG), and Multiple Sleep Latency Test (MSLT) parameters. CSF and plasma MCH levels were not significantly different between narcolepsy patients regardless of ICSD-3 subtype, HCRT-1 levels, or compared to controls. CSF MCH and HCRT-1 levels were not significantly correlated. Multivariate regression models of CSF MCH levels, age, sex, and body mass index predicting clinical, PSG, and MSLT parameters did not reveal any significant associations to CSF MCH levels. Our study shows that MCH levels in CSF collected in the morning are normal in narcolepsy and not associated with the clinical symptoms, REM sleep abnormalities, nor number of muscle movements during REM or NREM sleep of the patients. We conclude that morning lumbar CSF MCH measurement is not an informative diagnostic marker for narcolepsy. © 2017 American Academy of Sleep Medicine

The anatomical, cellular and synaptic basis of motor atonia during rapid eye movement sleep

PubMed Central

Chen, Michael C.

2016-01-01

Abstract Rapid eye movement (REM) sleep is a recurring part of the sleep–wake cycle characterized by fast, desynchronized rhythms in the electroencephalogram (EEG), hippocampal theta activity, rapid eye movements, autonomic activation and loss of postural muscle tone (atonia). The brain circuitry governing REM sleep is located in the pontine and medullary brainstem and includes ascending and descending projections that regulate the EEG and motor components of REM sleep. The descending signal for postural muscle atonia during REM sleep is thought to originate from glutamatergic neurons of the sublaterodorsal nucleus (SLD), which in turn activate glycinergic pre‐motor neurons in the spinal cord and/or ventromedial medulla to inhibit motor neurons. Despite work over the past two decades on many neurotransmitter systems that regulate the SLD, gaps remain in our knowledge of the synaptic basis by which SLD REM neurons are regulated and in turn produce REM sleep atonia. Elucidating the anatomical, cellular and synaptic basis of REM sleep atonia control is a critical step for treating many sleep‐related disorders including obstructive sleep apnoea (apnea), REM sleep behaviour disorder (RBD) and narcolepsy with cataplexy. PMID:27060683

Eye Movement Disorders

MedlinePlus

... t work properly. There are many kinds of eye movement disorders. Two common ones are Strabismus - a disorder ... of the eyes, sometimes called "dancing eyes" Some eye movement disorders are present at birth. Others develop over ...

Electroencephalographic findings related with mild cognitive impairment in idiopathic rapid eye movement sleep behavior disorder.

PubMed

Sasai, Taeko; Matsuura, Masato; Inoue, Yuichi

2013-12-01

Mild cognitive impairment (MCI) and electroencephalographic (EEG) slowing have been reported as common findings of idiopathic rapid eye movement (REM) sleep behavior disorder (iRBD) and α-synucleinopathies. The objective of this study is to clarify the relation between MCI and physiological markers in iRBD. Cross-sectional study. Yoyogi Sleep Disorder Center. Thirty-one patients with iRBD including 17 younger patients with iRBD (younger than 70 y) and 17 control patients for the younger patients with iRBD. N/A. Montreal Cognitive Assessment (MoCA) and n-polysomnogram (PSG) were conducted of all participants. In patients with iRBD, the factors associated with MCI were explored among parameters of REM sleep without atonia (RWA), score of Sniffin' Sticks Test (threshold-discrimination-identification [TDI] score), RBD morbidity, and RBD severity evaluated with the Japanese version of the RBD questionnaire (RBDQ-JP). The younger iRBD group showed significantly lower alpha power during wake and lower MoCA score than the age-matched control group. MCI was detected in 13 of 17 patients (76.5%) on MoCA in this group. Among patients wtih iRBD, the MoCA score negatively correlated with age, proportion of slow wave sleep, TDI score, and EEG spectral power. Multiple regression analysis provided the following equation: MoCA score = 50.871-0.116*age -5.307*log (δ power during REM sleep) + 0.086*TDI score (R² = 0.598, P < 0.01). The standardized partial regression coefficients were -0.558 for age, -0.491 for log (δ power during REM sleep), and 0.357 for TDI score (F = 9.900, P < 0.001). Electroencephalographic slowing, especially during rapid eye movement sleep and olfactory dysfunction, was revealed to be associated with cognitive decline in idiopathic rapid eye movement sleep behavior disorder.

Sleep-wake patterns, non-rapid eye movement, and rapid eye movement sleep cycles in teenage narcolepsy.

PubMed

Xu, Xing; Wu, Huijuan; Zhuang, Jianhua; Chen, Kun; Huang, Bei; Zhao, Zhengqing; Zhao, Zhongxin

2017-05-01

To further characterize sleep disorders associated with narcolepsy, we assessed the sleep-wake patterns, rapid eye movement (REM), and non-REM (NREM) sleep cycles in Chinese teenagers with narcolepsy. A total of 14 Chinese type 1 narcoleptic patients (13.4 ± 2.6 years of age) and 14 healthy age- and sex-matched control subjects (13.6 ± 1.8 years of age) were recruited. Ambulatory 24-h polysomnography was recorded for two days, with test subjects adapting to the instruments on day one and the study data collection performed on day two. Compared with the controls, the narcoleptic patients showed a 1.5-fold increase in total sleep time over 24 h, characterized by enhanced slow-wave sleep and REM sleep. Frequent sleep-wake transitions were identified in nocturnal sleep with all sleep stages switching to wakefulness, with more awakenings and time spent in wakefulness after sleep onset. Despite eight cases of narcolepsy with sleep onset REM periods at night, the mean duration of NREM-REM sleep cycle episode and the ratio of REM/NREM sleep between patients and controls were not significantly different. Our study identified hypersomnia in teenage narcolepsy despite excessive daytime sleepiness. Sleep fragmentation extended to all sleep stages, indicating impaired sleep-wake cycles and instability of sleep stages. The limited effects on NREM-REM sleep cycles suggest the relative conservation of ultradian regulation of sleep. Copyright © 2016 Elsevier B.V. All rights reserved.

Rapid eye movement sleep behavior disorder.

PubMed

Gugger, James J; Wagner, Mary L

2007-11-01

To describe the clinical features of rapid eye movement (REM) sleep behavior disorder (RBD), evaluate treatment options, and discuss management of patients with comorbid diseases. A MEDLINE search (1977-April 2007) using the terms REM sleep behavior disorder, narcolepsy, parkinsonian disorders, levodopa, dopamine agonists, clonazepam, benzodiazepines, and melatonin was used to retrieve relevant articles. The reference sections of all articles and texts were scanned for additional literature. All articles published in English were evaluated. There were no specific criteria for inclusion of articles in this review. RBD is characterized by enactment of dream content resulting from the loss of normal skeletal muscle atonia during REM sleep. RBD occurs mainly in geriatric patients and in patients with neurodegenerative diseases, especially parkinsonian diseases. The presence of idiopathic RBD may be a sign of an underlying parkinsonian syndrome. Development of RBD may be one of the first manifestations of Parkinson's disease or other parkinsonian syndromes. An acute form of RBD can be drug-induced or occur on drug withdrawal. The potential for injury to the patient and his or her bed partner is as high as 96%. Controlled trials are unavailable for most agents used in the treatment of RBD, although clonazepam is an effective first-line agent and can provide rapid and complete symptom remission based on evidence from 3 large case series. Patients who cannot tolerate clonazepam or who have a suboptimal response may benefit from melatonin alone or as an adjunct. Both drugs are generally well tolerated when taken at bedtime. Management of patients with RBD becomes complicated due to the high incidence of neurologic comorbidity. Clonazepam is the treatment of choice for patients with RBD. The drug is efficacious and has a low incidence of adverse effects. Melatonin is a viable second-line or adjunctive treatment.

Relationships between Rapid Eye Movement Sleep Behavior Disorder and Neurodegenerative Diseases: Clinical Assessments, Biomarkers, and Treatment

PubMed Central

Li, Min; Wang, Li; Liu, Jiang-Hong; Zhan, Shu-Qin

2018-01-01

Objective: Rapid eye movement sleep behavior disorder (RBD) is characterized by dream enactment and loss of muscle atonia during rapid eye movement sleep. RBD is closely related to α-synucleinopathies including Parkinson's disease, dementia with Lewy bodies, and multiple system atrophy. Many studies have investigated the markers of imaging and neurophysiological, genetic, cognitive, autonomic function of RBD and their predictive value for neurodegenerative diseases. This report reviewed the progress of these studies and discussed their limitations and future research directions. Data Sources: Using the combined keywords: “RBD”, “neurodegenerative disease”, “Parkinson disease”, and “magnetic resonance imaging”, the PubMed/MEDLINE literature search was conducted up to January 1, 2018. Study Selection: A total of 150 published articles were initially identified citations. Of the 150 articles, 92 articles were selected after further detailed review. This study referred to all the important English literature in full. Results: Single-nucleotide polymorphisms in SCARB2 (rs6812193) and MAPT (rs12185268) were significantly associated with RBD. The olfactory loss, autonomic dysfunction, marked electroencephalogram slowing during both wakefulness and rapid eye movement sleep, and cognitive impairments were potential predictive markers for RBD conversion to neurodegenerative diseases. Traditional structural imaging studies reported relatively inconsistent results, whereas reduced functional connectivity between the left putamen and substantia nigra and dopamine transporter uptake demonstrated by functional imaging techniques were relatively consistent findings. Conclusions: More longitudinal studies should be conducted to evaluate the predictive value of biomarkers of RBD. Moreover, because the glucose and dopamine metabolisms are not specific for assessing cognitive cognition, the molecular metabolism directly related to cognition should be investigated

Comparison of rhythmic masticatory muscle activity during non-rapid eye movement sleep in guinea pigs and humans.

PubMed

Kato, Takafumi; Toyota, Risa; Haraki, Shingo; Yano, Hiroyuki; Higashiyama, Makoto; Ueno, Yoshio; Yano, Hiroshi; Sato, Fumihiko; Yatani, Hirofumi; Yoshida, Atsushi

2017-09-27

Rhythmic masticatory muscle activity can be a normal variant of oromotor activity, which can be exaggerated in patients with sleep bruxism. However, few studies have tested the possibility in naturally sleeping animals to study the neurophysiological mechanisms of rhythmic masticatory muscle activity. This study aimed to investigate the similarity of cortical, cardiac and electromyographic manifestations of rhythmic masticatory muscle activity occurring during non-rapid eye movement sleep between guinea pigs and human subjects. Polysomnographic recordings were made in 30 freely moving guinea pigs and in eight healthy human subjects. Burst cycle length, duration and activity of rhythmic masticatory muscle activity were compared with those for chewing. The time between R-waves in the electrocardiogram (RR interval) and electroencephalogram power spectrum were calculated to assess time-course changes in cardiac and cortical activities in relation to rhythmic masticatory muscle activity. In animals, in comparison with chewing, rhythmic masticatory muscle activity had a lower burst activity, longer burst duration and longer cycle length (P < 0.05), and greater variabilities were observed (P < 0.05). Rhythmic masticatory muscle activity occurring during non-rapid eye movement sleep [median (interquartile range): 5.2 (2.6-8.9) times per h] was preceded by a transient decrease in RR intervals, and was accompanied by a transient decrease in delta elelctroencephalogram power. In humans, masseter bursts of rhythmic masticatory muscle activity were characterized by a lower activity, longer duration and longer cycle length than those of chewing (P < 0.05). Rhythmic masticatory muscle activity during non-rapid eye movement sleep [1.4 (1.18-2.11) times per h] was preceded by a transient decrease in RR intervals and an increase in cortical activity. Rhythmic masticatory muscle activity in animals had common physiological components representing transient arousal

[Microinjections of heat shock protein 70 kDa into the nucleus reticularis pontis oralis induce inhibition of rapid eye movement sleep in pigeons].

PubMed

Gusel'nikova, E A; Pastukhov, Iu F

2008-03-01

Recently it was indicated that microinjections of heat shock proteins 70 kDa (Hsp70) into the third ventricle of brain in pigeons results in an increase in the duration of slow wave sleep and a decrease in somato-visceral indices. It is suggested that Hsp70 effect may be related to GABA(A) receptors activation in the preoptic area of the hypothalamus. However, what transmitter mechanisms of activation are related to the removal effect (in 2-3 hrs) of rapid eye movement sleep inhibition still remains poorly understood. To solve this problem in the present study, microinjections of Hsp70 into the Nucleus reticularis pontis oralis (NRPO) were done. It is well known that cholinergic neurons of the NRPO are crucial for rapid eye movement sleep generation. The data show that Hsp70 produces more early (for first two hrs) a decrease in number of episodes and total time of rapid eye movement sleep, a diminution of electroencephalogram (EEG) power spectra in the 9-14 Hz band, a decrease in contractile muscle activity and brain temperature. It is suggested that Hsp70 effects are realized due to activation of GABA(A) receptors in the NRPO and induced inhibition of cholinergic mechanisms of rapid eye movement sleep triggering. The microinjections of Hsp70 into the NRPO increase the slow wave sleep total time with long latency (for 8-12 hrs). This effect may be related to influence of Hsp70 on neurons population, which are responsible for slow wave sleep maintenance outside the NRPO.

Pioneers of eye movement research

PubMed Central

Wade, Nicholas J

2010-01-01

Recent advances in the technology affording eye movement recordings carry the risk of neglecting past achievements. Without the assistance of this modern armoury, great strides were made in describing the ways the eyes move. For Aristotle the fundamental features of eye movements were binocular, and he described the combined functions of the eyes. This was later given support using simple procedures like placing a finger over the eyelid of the closed eye and culminated in Hering's law of equal innervation. However, the overriding concern in the 19th century was with eye position rather than eye movements. Appreciating discontinuities of eye movements arose from studies of vertigo. The characteristics of nystagmus were recorded before those of saccades and fixations. Eye movements during reading were described by Hering and by Lamare in 1879; both used similar techniques of listening to sounds made during contractions of the extraocular muscles. Photographic records of eye movements during reading were made by Dodge early in the 20th century, and this stimulated research using a wider array of patterns. In the mid-20th century attention shifted to the stability of the eyes during fixation, with the emphasis on involuntary movements. The contributions of pioneers from Aristotle to Yarbus are outlined. PMID:23396982

Eye movement perimetry in glaucoma.

PubMed

Trope, G E; Eizenman, M; Coyle, E

1989-08-01

Present-day computerized perimetry is often inaccurate and unreliable owing to the need to maintain central fixation over long periods while repressing the normal response to presentation of peripheral stimuli. We tested a new method of perimetry that does not require prolonged central fixation. During this test eye movements were encouraged on presentation of a peripheral target. Twenty-three eyes were studied with an Octopus perimeter, with a technician monitoring eye movements. The sensitivity was 100% and the specificity 23%. The low specificity was due to the technician's inability to accurately monitor small eye movements in the central 6 degrees field. If small eye movements are monitored accurately with an eye tracker, eye movement perimetry could become an alternative method to standard perimetry.

Pursuit Eye Movements

NASA Technical Reports Server (NTRS)

Krauzlis, Rich; Stone, Leland; Null, Cynthia H. (Technical Monitor)

1998-01-01

When viewing objects, primates use a combination of saccadic and pursuit eye movements to stabilize the retinal image of the object of regard within the high-acuity region near the fovea. Although these movements involve widespread regions of the nervous system, they mix seamlessly in normal behavior. Saccades are discrete movements that quickly direct the eyes toward a visual target, thereby translating the image of the target from an eccentric retinal location to the fovea. In contrast, pursuit is a continuous movement that slowly rotates the eyes to compensate for the motion of the visual target, minimizing the blur that can compromise visual acuity. While other mammalian species can generate smooth optokinetic eye movements - which track the motion of the entire visual surround - only primates can smoothly pursue a single small element within a complex visual scene, regardless of the motion elsewhere on the retina. This ability likely reflects the greater ability of primates to segment the visual scene, to identify individual visual objects, and to select a target of interest.

Fragmentation of Rapid Eye Movement and Nonrapid Eye Movement Sleep without Total Sleep Loss Impairs Hippocampus-Dependent Fear Memory Consolidation.

PubMed

Lee, Michael L; Katsuyama, Ângela M; Duge, Leanne S; Sriram, Chaitra; Krushelnytskyy, Mykhaylo; Kim, Jeansok J; de la Iglesia, Horacio O

2016-11-01

Sleep is important for consolidation of hippocampus-dependent memories. It is hypothesized that the temporal sequence of nonrapid eye movement (NREM) sleep and rapid eye movement (REM) sleep is critical for the weakening of nonadaptive memories and the subsequent transfer of memories temporarily stored in the hippocampus to more permanent memories in the neocortex. A great body of evidence supporting this hypothesis relies on behavioral, pharmacological, neural, and/or genetic manipulations that induce sleep deprivation or stage-specific sleep deprivation. We exploit an experimental model of circadian desynchrony in which intact animals are not deprived of any sleep stage but show fragmentation of REM and NREM sleep within nonfragmented sleep bouts. We test the hypothesis that the shortening of NREM and REM sleep durations post-training will impair memory consolidation irrespective of total sleep duration. When circadian-desynchronized animals are trained in a hippocampus-dependent contextual fear-conditioning task they show normal short-term memory but impaired long-term memory consolidation. This impairment in memory consolidation is positively associated with the post-training fragmentation of REM and NREM sleep but is not significantly associated with the fragmentation of total sleep or the total amount of delta activity. We also show that the sleep stage fragmentation resulting from circadian desynchrony has no effect on hippocampus-dependent spatial memory and no effect on hippocampus-independent cued fear-conditioning memory. Our findings in an intact animal model, in which sleep deprivation is not a confounding factor, support the hypothesis that the stereotypic sequence and duration of sleep stages play a specific role in long-term hippocampus-dependent fear memory consolidation. © 2016 Associated Professional Sleep Societies, LLC.

Asymmetries in the Control of Saccadic Eye Movements to Bifurcating Targets.

ERIC Educational Resources Information Center

Zeevi, Yehoshua Y.; And Others

The examination of saccadic eye movements--rapid shifts in gaze from one visual area of interest to another--is useful in studying pilot's visual learning in flight simulator training. Saccadic eye movements are the basic oculomotor response associated with the acquisition of visual information and provide an objective measure of higher perceptual…

Fight or flight? Dream content during sleepwalking/sleep terrors vs. rapid eye movement sleep behavior disorder.

PubMed

Uguccioni, Ginevra; Golmard, Jean-Louis; de Fontréaux, Alix Noël; Leu-Semenescu, Smaranda; Brion, Agnès; Arnulf, Isabelle

2013-05-01

Dreams enacted during sleepwalking or sleep terrors (SW/ST) may differ from those enacted during rapid eye movement sleep behavior disorder (RBD). Subjects completed aggression, depression, and anxiety questionnaires. The mentations associated with SW/ST and RBD behaviors were collected over their lifetime and on the morning after video polysomnography (PSG). The reports were analyzed for complexity, length, content, setting, bizarreness, and threat. Ninety-one percent of 32 subjects with SW/ST and 87.5% of 24 subjects with RBD remembered an enacted dream (121 dreams in a lifetime and 41 dreams recalled on the morning). These dreams were more complex and less bizarre, with a higher level of aggression in the RBD than in SW/ST subjects. In contrast, we found low aggression, anxiety, and depression scores during the daytime in both groups. As many as 70% of enacted dreams in SW/ST and 60% in RBD involved a threat, but there were more misfortunes and disasters in the SW/ST dreams and more human and animal aggressions in the RBD dreams. The response to these threats differed, as the sleepwalkers mostly fled from a disaster (and 25% fought back when attacked), while 75% of RBD subjects counterattacked when assaulted. The dreams setting included their bedrooms in 42% SW/ST dreams, though this finding was exceptional in the RBD dreams. Different threat simulations and modes of defense seem to play a role during dream-enacted behaviors (e.g., fleeing a disaster during SW/ST, counterattacking a human or animal assault during RBD), paralleling and exacerbating the differences observed between normal dreaming in nonrapid eye movement (NREM) vs rapid eye movement (REM) sleep. Copyright © 2013 Elsevier B.V. All rights reserved.

Eye-movements and ongoing task processing.

PubMed

Burke, David T; Meleger, Alec; Schneider, Jeffrey C; Snyder, Jim; Dorvlo, Atsu S S; Al-Adawi, Samir

2003-06-01

This study tests the relation between eye-movements and thought processing. Subjects were given specific modality tasks (visual, gustatory, kinesthetic) and assessed on whether they responded with distinct eye-movements. Some subjects' eye-movements reflected ongoing thought processing. Instead of a universal pattern, as suggested by the neurolinguistic programming hypothesis, this study yielded subject-specific idiosyncratic eye-movements across all modalities. Included is a discussion of the neurolinguistic programming hypothesis regarding eye-movements and its implications for the eye-movement desensitization and reprocessing theory.

Reduced Rapid Eye Movement Density in Parkinson Disease: A Polysomnography-Based Case-Control Study.

PubMed

Schroeder, Lynn A; Rufra, Olivier; Sauvageot, Nicolas; Fays, François; Pieri, Vannina; Diederich, Nico J

2016-12-01

To explore rapid eye movement density (RD) in patients with idiopathic Parkinson disease (IPD) and to investigate its usefulness as surrogate marker of excessive daytime sleepiness, a frequent complaint in IPD patients. Retrospective polysomnography study on 81 subjects without dementia: 29 patients with early stage IPD (disease duration ≤ 3 y), 21 patients with middle- stage IPD (disease duration > 3 and < 8 y) and 31 healthy controls (HC). Rapid eye movement (REM) sleep was defined as any REM episode with > 3 min of continuous REM sleep. RD was defined as number of ocular movements per minute of REM sleep. Patients with early stage IPD and HC fulfilled the PD-specific sleepiness questionnaires Parkinson's Disease Sleep Scale (PDSS) and the Nonmotor Symptoms Questionnaire for Parkinson's disease (NMSQuest). RD was lower in patients with IPD than in HC. The difference was most significant between patients with middle stage IPD and HC (P = 0.001), and most prominent for the third REM episode, again when comparing patients with middle stage IPD and HC (P = 0.03). RD was independent from sex, age, and other sleep parameters. In early stage IPD, RD correlated with the PDSS score (r = -0.63, P = 0.001) and the sleep-related questions of the NMSQuest score (r = 0.48, P = 0.017). REM density is reduced in patients with IPD and correlates with subjective scores on sleep impairment. As an indicator of persistent high sleep pressure, reduced RD in IPD is eligible as a biomarker of excessive daytime sleepiness in IPD. It possibly reflects direct involvement of the brainstem REM generation sites by the disease process. RD is a promising new tool for sleep research in IPD. © 2016 Associated Professional Sleep Societies, LLC.

Rapid Eye Movement Sleep Behavior Disorder in Paraneoplastic Cerebellar Degeneration: Improvement with Immunotherapy.

PubMed

Vale, Thiago Cardoso; Fernandes do Prado, Lucila Bizari; do Prado, Gilmar Fernandes; Povoas Barsottini, Orlando Graziani; Pedroso, José Luiz

2016-01-01

To report two female patients with paraneoplastic cerebellar degeneration (PCD) related to breast cancer that presented with rapid eye movement-sleep behavior disorder (RBD) and improved sleep symptoms with immunotherapy. The two patients were evaluated through clinical scale and polysomnography before and after therapy with intravenous immunoglobulin. RBD was successfully treated with immunotherapy in both patients. Score on the RBD screening questionnaire dropped from 10 to 1 or 0, allied with the normalization of polysomnographic findings. A marked improvement in RBD after immunotherapy in PCD raises the hypothesis that secondary RBD may be an immune-mediated sleep disorder. © 2016 Associated Professional Sleep Societies, LLC.

PC-based high-speed video-oculography for measuring rapid eye movements in mice.

PubMed

Sakatani, Tomoya; Isa, Tadashi

2004-05-01

We newly developed an infrared video-oculographic system for on-line tracking of the eye position in awake and head-fixed mice, with high temporal resolution (240 Hz). The system consists of a commercially available high-speed CCD camera and an image processing software written in LabVIEW run on IBM-PC with a plug-in video grabber board. This software calculates the center and area of the pupil by fitting circular function to the pupil boundary, and allows robust and stable tracking of the eye position in small animals like mice. On-line calculation is performed to obtain reasonable circular fitting of the pupil boundary even if a part of the pupil is covered with shadows or occluded by eyelids or corneal reflections. The pupil position in the 2-D video plane is converted to the rotation angle of the eyeball by estimating its rotation center based on the anatomical eyeball model. By this recording system, it is possible to perform quantitative analysis of rapid eye movements such as saccades in mice. This will provide a powerful tool for analyzing molecular basis of oculomotor and cognitive functions by using various lines of mutant mice.

Shorter duration of non-rapid eye movement sleep slow waves in EphA4 knockout mice.

PubMed

Freyburger, Marlène; Poirier, Gaétan; Carrier, Julie; Mongrain, Valérie

2017-10-01

Slow waves occurring during non-rapid eye movement sleep have been associated with neurobehavioural performance and memory. In addition, the duration of previous wakefulness and sleep impacts characteristics of these slow waves. However, molecular mechanisms regulating the dynamics of slow-wave characteristics remain poorly understood. The EphA4 receptor regulates glutamatergic transmission and synaptic plasticity, which have both been linked to sleep slow waves. To investigate if EphA4 regulates slow-wave characteristics during non-rapid eye movement sleep, we compared individual parameters of slow waves between EphA4 knockout mice and wild-type littermates under baseline conditions and after a 6-h sleep deprivation. We observed that, compared with wild-type mice, knockout mice display a shorter duration of positive and negative phases of slow waves under baseline conditions and after sleep deprivation. However, the mutation did not change slow-wave density, amplitude and slope, and did not affect the sleep deprivation-dependent changes in slow-wave characteristics, suggesting that EphA4 is not involved in the response to elevated sleep pressure. Our present findings suggest a role for EphA4 in shaping cortical oscillations during sleep that is independent from sleep need. © 2017 European Sleep Research Society.

ECEM (Eye Closure, Eye Movements): application to depersonalization disorder.

PubMed

Harriet, E Hollander

2009-10-01

Eye Closure, Eye Movements (ECEM) is a hypnotically-based approach to treatment that incorporates eye movements adapted from the Eye Movement Desensitization and Reprocessing (EMDR) protocol in conjunction with hypnosis for the treatment of depersonalization disorder. Depersonalization Disorder has been differentiated from post-traumatic stress disorders and has recently been conceptualized as a subtype of panic disorder (Baker et al., 2003; David, Phillips, Medford, & Sierra, 2004; Segui et. al., 2000). During ECEM, while remaining in a hypnotic state, clients self-generated six to seven trials of eye movements to reduce anticipatory anxiety associated with depersonalization disorder. Eye movements were also used to process triggers that elicited breath holding, often followed by episodes of depersonalization. Hypnotic suggestions were used to reverse core symptoms of depersonalization, subjectively described as "feeling unreal" (Simeon et al., 1997).

[Electromyography Analysis of Rapid Eye Movement Sleep Behavior Disorder].

PubMed

Nakano, Natsuko; Kinoshita, Fumiya; Takada, Hiroki; Nakayama, Meiho

2018-01-01

Polysomnography (PSG), which records physiological phenomena including brain waves, breathing status, and muscle tonus, is useful for the diagnosis of sleep disorders as a gold standard. However, measurement and analysis are complex for several specific sleep disorders, such as rapid eye movement (REM) sleep behavior disorder (RBD). Usually, brain waves during REM sleep indicate an awakening pattern under relaxed conditions of skeletal and antigravity muscles. However, these muscles are activated during REM sleep when patients suffer from RBD. These activated muscle movements during REM, so-called REM without atonia (RWA) recorded by PSG, may be related to a neurodegenerative disease such as Parkinson's disease. Thus, careful analysis of RWA is significant not only physically, but also clinically. Commonly, manual viewing measurement analysis of RWA is time-consuming. Therefore, quantitative studies on RWA are rarely reported. A software program, developed from Microsoft Office Excel ® , was used to semiautomatically analyze the RWA ratio extracted from PSG to compare with manual viewing measurement analysis. In addition, a quantitative muscle tonus study was carried out to evaluate the effect of medication on RBD patients. Using this new software program, we were able to analyze RWA on the same cases in approximately 15 min as compared with 60 min in the manual viewing measurement analysis. This software program can not only quantify RWA easily but also identify RWA waves for either phasic or tonic bursts. We consider that this software program will support physicians and scientists in their future research on RBD. We are planning to offer this software program for free to physicians and scientists.

On Biometrics With Eye Movements.

PubMed

Zhang, Youming; Juhola, Martti

2017-09-01

Eye movements are a relatively novel data source for biometric identification. When video cameras applied to eye tracking become smaller and more efficient, this data source could offer interesting opportunities for the development of eye movement biometrics. In this paper, we study primarily biometric identification as seen as a classification task of multiple classes, and secondarily biometric verification considered as binary classification. Our research is based on the saccadic eye movement signal measurements from 109 young subjects. In order to test the data measured, we use a procedure of biometric identification according to the one-versus-one (subject) principle. In a development from our previous research, which also involved biometric verification based on saccadic eye movements, we now apply another eye movement tracker device with a higher sampling frequency of 250 Hz. The results obtained are good, with correct identification rates at 80-90% at their best.

Remifentanil inhibits rapid eye movement sleep but not the nocturnal melatonin surge in humans.

PubMed

Bonafide, Christopher P; Aucutt-Walter, Natalie; Divittore, Nicole; King, Tonya; Bixler, Edward O; Cronin, Arthur J

2008-04-01

Postoperative patients are sleep deprived. Opioids, commonly administered for postoperative pain control, are often mistakenly considered inducers of naturally occurring sleep. This study describes the effect of the opioid remifentanil on nocturnal sleep in healthy volunteers. In addition, this study tests the hypothesis that opioid-induced sleep disturbance is caused by a circadian pacemaker disturbance, reflected by suppressed nocturnal plasma concentration of melatonin. Polysomnography was performed in 10 volunteers from 11:00 pm to 7:00 am for four nights at 6-day intervals. On two nights, remifentanil (0.01-0.04 microg x kg x min) was infused from 10:30 pm to 7:00 am, and either a placebo capsule or 3.0 mg melatonin was administered at 10:30 pm. On two additional nights, saline was infused, and the placebo or melatonin capsules were administered at 10:30 pm. Blood was drawn at 12:00 am, 3:00 am, and 6:00 am to measure the plasma concentration of melatonin and cortisol. A repeated-measures analysis of variance model was used to determine the effect of remifentanil on sleep stages, the effect of remifentanil on the plasma concentration of melatonin, and the effect of exogenous melatonin on remifentanil-induced sleep disturbance. Remifentanil inhibited rapid eye movement sleep (14.1 +/- 7.2% to 3.9 +/- 6.9%). The amount of slow wave sleep decreased from 6.8 +/- 7.6% to 3.2 +/- 6.1%, but this decrease was not statistically significant. Remifentanil did not decrease melatonin concentration. Melatonin administration did not prevent remifentanil-induced sleep disturbance. An overnight constant infusion of remifentanil inhibits rapid eye movement sleep without suppressing the nocturnal melatonin surge.

First rapid eye movement sleep periods and sleep-onset rapid eye movement periods in sleep-stage sequencing of hypersomnias.

PubMed

Drakatos, Panagis; Kosky, Christopher A; Higgins, Sean E; Muza, Rexford T; Williams, Adrian J; Leschziner, Guy D

2013-09-01

Discrimination between narcolepsy, idiopathic hypersomnia, and behavior-induced inadequate sleep syndrome (BIISS) is based on clinical features and on specific nocturnal polysomnography (NPSG) and multiple sleep latency test (MSLT) results. However, previous studies have cast doubt on the specificity and sensitivity of these diagnostic tools. Eleven variables of the NPSG were analyzed in 101 patients who were retrospectively diagnosed with narcolepsy with cataplexy (N+C) (n=24), narcolepsy without cataplexy (N-C) (n=38), idiopathic hypersomnia with long sleep period (IHL) (n=21), and BIISS (n=18). Fifteen out of 24 N+C and 8 out of 38 N-C entered the first rapid eye movement (REM) sleep period (FREMP) from sleep stage 1 (N1) or wake (W), though this sleep-stage sequence did not arise in the other patient groups. FREMP stage sequence was a function of REM sleep latency (REML) for both N+C and N-C groups. FREMP stage sequence was not associated with mean sleep latency (MSL) in N+C but was associated in N-C, which implies heterogeneity within the N-C group. REML also was a useful discriminator. Depending on the cutoff period, REML had a sensitivity and specificity of up to 85.5% and 97.4%, respectively. The FREMP stage sequence may be a useful tool in the diagnosis of narcolepsy, particularly in conjunction with sleep-stage sequence analysis of sleep-onset REM periods (SOREMPs) in the MSLT; it also may provide a helpful intermediate phenotype in the clarification of heterogeneity in the N-C diagnostic group. However, larger prospective studies are necessary to confirm these findings. Copyright © 2013 Elsevier B.V. All rights reserved.

Eye movements when viewing advertisements

PubMed Central

Higgins, Emily; Leinenger, Mallorie; Rayner, Keith

2013-01-01

In this selective review, we examine key findings on eye movements when viewing advertisements. We begin with a brief, general introduction to the properties and neural underpinnings of saccadic eye movements. Next, we provide an overview of eye movement behavior during reading, scene perception, and visual search, since each of these activities is, at various times, involved in viewing ads. We then review the literature on eye movements when viewing print ads and warning labels (of the kind that appear on alcohol and tobacco ads), before turning to a consideration of advertisements in dynamic media (television and the Internet). Finally, we propose topics and methodological approaches that may prove to be useful in future research. PMID:24672500

Eye Movements in Risky Choice

PubMed Central

Hermens, Frouke; Matthews, William J.

2015-01-01

Abstract We asked participants to make simple risky choices while we recorded their eye movements. We built a complete statistical model of the eye movements and found very little systematic variation in eye movements over the time course of a choice or across the different choices. The only exceptions were finding more (of the same) eye movements when choice options were similar, and an emerging gaze bias in which people looked more at the gamble they ultimately chose. These findings are inconsistent with prospect theory, the priority heuristic, or decision field theory. However, the eye movements made during a choice have a large relationship with the final choice, and this is mostly independent from the contribution of the actual attribute values in the choice options. That is, eye movements tell us not just about the processing of attribute values but also are independently associated with choice. The pattern is simple—people choose the gamble they look at more often, independently of the actual numbers they see—and this pattern is simpler than predicted by decision field theory, decision by sampling, and the parallel constraint satisfaction model. © 2015 The Authors. Journal of Behavioral Decision Making published by John Wiley & Sons Ltd. PMID:27522985

The perception of heading during eye movements

NASA Technical Reports Server (NTRS)

Royden, Constance S.; Banks, Martin S.; Crowell, James A.

1992-01-01

Warren and Hannon (1988, 1990), while studying the perception of heading during eye movements, concluded that people do not require extraretinal information to judge heading with eye/head movements present. Here, heading judgments are examined at higher, more typical eye movement velocities than the extremely slow tracking eye movements used by Warren and Hannon. It is found that people require extraretinal information about eye position to perceive heading accurately under many viewing conditions.

Intersegmental Eye-Head-Body Interactions during Complex Whole Body Movements

PubMed Central

von Laßberg, Christoph; Beykirch, Karl A.; Mohler, Betty J.; Bülthoff, Heinrich H.

2014-01-01

Using state-of-the-art technology, interactions of eye, head and intersegmental body movements were analyzed for the first time during multiple twisting somersaults of high-level gymnasts. With this aim, we used a unique combination of a 16-channel infrared kinemetric system; a three-dimensional video kinemetric system; wireless electromyography; and a specialized wireless sport-video-oculography system, which was able to capture and calculate precise oculomotor data under conditions of rapid multiaxial acceleration. All data were synchronized and integrated in a multimodal software tool for three-dimensional analysis. During specific phases of the recorded movements, a previously unknown eye-head-body interaction was observed. The phenomenon was marked by a prolonged and complete suppression of gaze-stabilizing eye movements, in favor of a tight coupling with the head, spine and joint movements of the gymnasts. Potential reasons for these observations are discussed with regard to earlier findings and integrated within a functional model. PMID:24763143

Relationship Between Eye Movement and Cognitive Information Acquisition Utilizing an Unobtrusive Eye Movement Monitoring Device.

ERIC Educational Resources Information Center

Nesbit, Larry L.

A research study was designed to test the relationship between the number of eye fixations and amount of learning as determined by a criterion referenced posttest. The study sought to answer the following questions: (1) Are differences in eye movement indices related to the posttest score? (2) Do differences in eye movement indices of subjects…

Rapid eye movement sleep behaviour disorder symptomatic of a brain stem cavernoma.

PubMed

Felix, Sandra; Thobois, Stephane; Peter-Derex, Laure

2016-04-01

A 75-year-old man complained of excessive daytime sleepiness (EDS), difficulty falling asleep and nocturnal agitation during sleep. Restless legs syndrome (RLS) was diagnosed and treated. Because of persistent EDS, snoring and nycturia, a nocturnal polysomnography (PSG) was performed. PSG showed high sleep fragmentation related to a moderate to severe obstructive sleep apnea syndrome. Continuous positive airway pressure treatment (CPAP) was proposed. Because of the persistence of abnormal nocturnal behaviours, characterized by screaming, punching and falling out of bed, a video-PSG with CPAP treatment was performed. The recording showed typical chin electromyography (EMG) activity increase associated with violent movements during rapid eye movement (REM) sleep, suggesting REM sleep behaviour disorders (RBD). Clinical neurological examination found no parkinsonian syndrome, no dysautonomic sign and no neurological focal sign. Dopamine transporter imaging [123I-FP-CIT single photon emission computed tomography (SPECT)] did not find any presynaptic dopaminergic pathways degeneration. Brain magnetic resonance imaging showed a vascular lesion suggestive of cavernoma located in the pons. The present case illustrates the complexity of sleep disturbance diagnosis with a possible entanglement of aetiologies responsible for nocturnal agitation, and confirms that an isolated pons cavernoma should be considered among the rare causes of RBD. © 2016 European Sleep Research Society.

Auditory Inhibition of Rapid Eye Movements and Dream Recall from REM Sleep

PubMed Central

Stuart, Katrina; Conduit, Russell

2009-01-01

Study Objectives: There is debate in dream research as to whether ponto-geniculo-occipital (PGO) waves or cortical arousal during sleep underlie the biological mechanisms of dreaming. This study comprised 2 experiments. As eye movements (EMs) are currently considered the best noninvasive indicator of PGO burst activity in humans, the aim of the first experiment was to investigate the effect of low-intensity repeated auditory stimulation on EMs (and inferred PGO burst activity) during REM sleep. It was predicted that such auditory stimuli during REM sleep would have a suppressive effect on EMs. The aim of the second experiment was to examine the effects of this auditory stimulation on subsequent dream reporting on awakening. Design: Repeated measures design with counterbalanced order of experimental and control conditions across participants. Setting: Sleep laboratory based polysomnography (PSG) Participants: Experiment 1: 5 males and 10 females aged 18-35 years (M = 20.8, SD = 5.4). Experiment 2: 7 males and 13 females aged 18-35 years (M = 23.3, SD = 5.5). Interventions: Below-waking threshold tone presentations during REM sleep compared to control REM sleep conditions without tone presentations. Measurements and Results: PSG records were manually scored for sleep stages, EEG arousals, and EMs. Auditory stimulation during REM sleep was related to: (a) an increase in EEG arousal, (b) a decrease in the amplitude and frequency of EMs, and (c) a decrease in the frequency of visual imagery reports on awakening. Conclusions: The results of this study provide phenomenological support for PGO-based theories of dream reporting on awakening from sleep in humans. Citation: Stuart K; Conduit R. Auditory inhibition of rapid eye movements and dream recall from REM sleep. SLEEP 2009;32(3):399–408. PMID:19294960

Learning optimal eye movements to unusual faces

PubMed Central

Peterson, Matthew F.; Eckstein, Miguel P.

2014-01-01

Eye movements, which guide the fovea’s high resolution and computational power to relevant areas of the visual scene, are integral to efficient, successful completion of many visual tasks. How humans modify their eye movements through experience with their perceptual environments, and its functional role in learning new tasks, has not been fully investigated. Here, we used a face identification task where only the mouth discriminated exemplars to assess if, how, and when eye movement modulation may mediate learning. By interleaving trials of unconstrained eye movements with trials of forced fixation, we attempted to separate the contributions of eye movements and covert mechanisms to performance improvements. Without instruction, a majority of observers substantially increased accuracy and learned to direct their initial eye movements towards the optimal fixation point. The proximity of an observer’s default face identification eye movement behavior to the new optimal fixation point and the observer’s peripheral processing ability were predictive of performance gains and eye movement learning. After practice in a subsequent condition in which observers were directed to fixate different locations along the face, including the relevant mouth region, all observers learned to make eye movements to the optimal fixation point. In this fully learned state, augmented fixation strategy accounted for 43% of total efficiency improvements while covert mechanisms accounted for the remaining 57%. The findings suggest a critical role for eye movement planning to perceptual learning, and elucidate factors that can predict when and how well an observer can learn a new task with unusual exemplars. PMID:24291712

Memory Reactivation during Rapid Eye Movement Sleep Promotes Its Generalization and Integration in Cortical Stores

PubMed Central

Sterpenich, Virginie; Schmidt, Christina; Albouy, Geneviève; Matarazzo, Luca; Vanhaudenhuyse, Audrey; Boveroux, Pierre; Degueldre, Christian; Leclercq, Yves; Balteau, Evelyne; Collette, Fabienne; Luxen, André; Phillips, Christophe; Maquet, Pierre

2014-01-01

Study Objectives: Memory reactivation appears to be a fundamental process in memory consolidation. In this study we tested the influence of memory reactivation during rapid eye movement (REM) sleep on memory performance and brain responses at retrieval in healthy human participants. Participants: Fifty-six healthy subjects (28 women and 28 men, age [mean ± standard deviation]: 21.6 ± 2.2 y) participated in this functional magnetic resonance imaging (fMRI) study. Methods and Results: Auditory cues were associated with pictures of faces during their encoding. These memory cues delivered during REM sleep enhanced subsequent accurate recollections but also false recognitions. These results suggest that reactivated memories interacted with semantically related representations, and induced new creative associations, which subsequently reduced the distinction between new and previously encoded exemplars. Cues had no effect if presented during stage 2 sleep, or if they were not associated with faces during encoding. Functional magnetic resonance imaging revealed that following exposure to conditioned cues during REM sleep, responses to faces during retrieval were enhanced both in a visual area and in a cortical region of multisensory (auditory-visual) convergence. Conclusions: These results show that reactivating memories during REM sleep enhances cortical responses during retrieval, suggesting the integration of recent memories within cortical circuits, favoring the generalization and schematization of the information. Citation: Sterpenich V, Schmidt C, Albouy G, Matarazzo L, Vanhaudenhuyse A, Boveroux P, Degueldre C, Leclercq Y, Balteau E, Collette F, Luxen A, Phillips C, Maquet P. Memory reactivation during rapid eye movement sleep promotes its generalization and integration in cortical stores. SLEEP 2014;37(6):1061-1075. PMID:24882901

Fetal Eye Movements on Magnetic Resonance Imaging

PubMed Central

Woitek, Ramona; Kasprian, Gregor; Lindner, Christian; Stuhr, Fritz; Weber, Michael; Schöpf, Veronika; Brugger, Peter C.; Asenbaum, Ulrika; Furtner, Julia; Bettelheim, Dieter; Seidl, Rainer; Prayer, Daniela

2013-01-01

Objectives Eye movements are the physical expression of upper fetal brainstem function. Our aim was to identify and differentiate specific types of fetal eye movement patterns using dynamic MRI sequences. Their occurrence as well as the presence of conjugated eyeball motion and consistently parallel eyeball position was systematically analyzed. Methods Dynamic SSFP sequences were acquired in 72 singleton fetuses (17–40 GW, three age groups [17–23 GW, 24–32 GW, 33–40 GW]). Fetal eye movements were evaluated according to a modified classification originally published by Birnholz (1981): Type 0: no eye movements; Type I: single transient deviations; Type Ia: fast deviation, slower reposition; Type Ib: fast deviation, fast reposition; Type II: single prolonged eye movements; Type III: complex sequences; and Type IV: nystagmoid. Results In 95.8% of fetuses, the evaluation of eye movements was possible using MRI, with a mean acquisition time of 70 seconds. Due to head motion, 4.2% of the fetuses and 20.1% of all dynamic SSFP sequences were excluded. Eye movements were observed in 45 fetuses (65.2%). Significant differences between the age groups were found for Type I (p = 0.03), Type Ia (p = 0.031), and Type IV eye movements (p = 0.033). Consistently parallel bulbs were found in 27.3–45%. Conclusions In human fetuses, different eye movement patterns can be identified and described by MRI in utero. In addition to the originally classified eye movement patterns, a novel subtype has been observed, which apparently characterizes an important step in fetal brainstem development. We evaluated, for the first time, eyeball position in fetuses. Ultimately, the assessment of fetal eye movements by MRI yields the potential to identify early signs of brainstem dysfunction, as encountered in brain malformations such as Chiari II or molar tooth malformations. PMID:24194885

Fetal eye movements on magnetic resonance imaging.

PubMed

Woitek, Ramona; Kasprian, Gregor; Lindner, Christian; Stuhr, Fritz; Weber, Michael; Schöpf, Veronika; Brugger, Peter C; Asenbaum, Ulrika; Furtner, Julia; Bettelheim, Dieter; Seidl, Rainer; Prayer, Daniela

2013-01-01

Eye movements are the physical expression of upper fetal brainstem function. Our aim was to identify and differentiate specific types of fetal eye movement patterns using dynamic MRI sequences. Their occurrence as well as the presence of conjugated eyeball motion and consistently parallel eyeball position was systematically analyzed. Dynamic SSFP sequences were acquired in 72 singleton fetuses (17-40 GW, three age groups [17-23 GW, 24-32 GW, 33-40 GW]). Fetal eye movements were evaluated according to a modified classification originally published by Birnholz (1981): Type 0: no eye movements; Type I: single transient deviations; Type Ia: fast deviation, slower reposition; Type Ib: fast deviation, fast reposition; Type II: single prolonged eye movements; Type III: complex sequences; and Type IV: nystagmoid. In 95.8% of fetuses, the evaluation of eye movements was possible using MRI, with a mean acquisition time of 70 seconds. Due to head motion, 4.2% of the fetuses and 20.1% of all dynamic SSFP sequences were excluded. Eye movements were observed in 45 fetuses (65.2%). Significant differences between the age groups were found for Type I (p = 0.03), Type Ia (p = 0.031), and Type IV eye movements (p = 0.033). Consistently parallel bulbs were found in 27.3-45%. In human fetuses, different eye movement patterns can be identified and described by MRI in utero. In addition to the originally classified eye movement patterns, a novel subtype has been observed, which apparently characterizes an important step in fetal brainstem development. We evaluated, for the first time, eyeball position in fetuses. Ultimately, the assessment of fetal eye movements by MRI yields the potential to identify early signs of brainstem dysfunction, as encountered in brain malformations such as Chiari II or molar tooth malformations.

Mortality and Its Risk Factors in Patients with Rapid Eye Movement Sleep Behavior Disorder

PubMed Central

Zhou, Junying; Zhang, Jihui; Lam, Siu Ping; Mok, Vincent; Chan, Anne; Li, Shirley Xin; Liu, Yaping; Tang, Xiangdong; Yung, Wing Ho; Wing, Yun Kwok

2016-01-01

Study Objectives: To determine the mortality and its risk factors in patients with rapid eye movement (REM) sleep behavior disorder (RBD). Methods: A total of 205 consecutive patients with video-polysomnography confirmed RBD (mean age = 66.4 ± 10.0 y, 78.5% males) were recruited. Medical records and death status were systematically reviewed in the computerized records of the health care system. Standardized mortality ratio (SMR) was used to calculate the risk ratio of mortality in RBD with reference to the general population. Results: Forty-three patients (21.0%) died over a mean follow-up period of 7.1 ± 4.5 y. The SMR was not increased in the overall sample, SMR (95% confidence interval [CI]) = 1.00 (0.73–1.33). However, SMR (95% CI) increased to 1.80 (1.21–2.58) and 1.75 (1.11–2.63) for RBD patients in whom neurodegenerative diseases and dementia, respectively, eventually developed. In the Cox regression model, mortality risk was significantly associated with age (hazard ratio [HR] = 1.05; 95% CI, 1.01–1.10), living alone (HR = 2.04; 95% CI, 1.39–2.99), chronic obstructive pulmonary disease (HR = 3.38; 95% CI, 1.21–9.46), cancer (HR = 10.09; 95% CI, 2.65–38.42), periodic limb movements during sleep (HR = 3.06; 95% CI, 1.50–6.24), and development of neurodegenerative diseases (HR = 2.84; 95% CI, 1.47–5.45) and dementia (HR = 2.66; 95% CI, 1.39–5.08). Conclusions: Patients with RBD have a higher mortality rate than the general population only if neurodegenerative diseases develop. Several risk factors on clinical and sleep aspects are associated with mortality in RBD patients. Our findings underscore the necessity of timely neuroprotective interventions in the early phase of RBD before the development of neurodegenerative diseases. Citation: Zhou J, Zhang J, Lam SP, Mok V, Chan A, Li SX, Liu Y, Tang X, Yung WH, Wing YK. Mortality and its risk factors in patients with rapid eye movement sleep behavior disorder. SLEEP 2016;39(8):1543–1550

Laughing as a manifestation of rapid eye movement sleep behavior disorder.

PubMed

Siclari, F; Wienecke, M; Poryazova, R; Bassetti, C L; Baumann, C R

2011-06-01

Among the range of sleep-related behavior displayed by patients with rapid eye movement (REM) sleep behavior disorder (RBD), aggressive acts are particularly common, while pleasant behaviors have rarely been reported. We aimed at identifying the frequency and characteristics of patients who displayed laughing as a pleasant, nonviolent manifestation of RBD. We reviewed 67 consecutive polysomnographic recordings of patients with RBD, obtained in our sleep laboratory between July 2004 and July 2009. We identified 14 patients (21% of our RBD patients with degenerative parkinsonism: 10 males, mean age 63 ± 11 years) who repeatedly laughed during REM sleep. Ten patients had idiopathic Parkinson's disease, 3 suffered from multisystem atrophy and 1 patient was diagnosed with dementia with Lewy bodies. Other RBD-associated behaviors included smiling, crying, aggressive behavior, screaming, and somniloquia. Nine of the 14 patients were depressed during daytime. Laughing belongs to the spectrum of behavioral manifestations of RBD. Many of our patients with RBD-associated laughter were depressed, suggesting a dissociation between emotional expression during daytime and REM sleep. Copyright © 2011 Elsevier Ltd. All rights reserved.

EYE MOVEMENT RECORDING AND NONLINEAR DYNAMICS ANALYSIS – THE CASE OF SACCADES#

PubMed Central

Aştefănoaei, Corina; Pretegiani, Elena; Optican, L.M.; Creangă, Dorina; Rufa, Alessandra

2015-01-01

Evidence of a chaotic behavioral trend in eye movement dynamics was examined in the case of a saccadic temporal series collected from a healthy human subject. Saccades are highvelocity eye movements of very short duration, their recording being relatively accessible, so that the resulting data series could be studied computationally for understanding the neural processing in a motor system. The aim of this study was to assess the complexity degree in the eye movement dynamics. To do this we analyzed the saccadic temporal series recorded with an infrared camera eye tracker from a healthy human subject in a special experimental arrangement which provides continuous records of eye position, both saccades (eye shifting movements) and fixations (focusing over regions of interest, with rapid, small fluctuations). The semi-quantitative approach used in this paper in studying the eye functioning from the viewpoint of non-linear dynamics was accomplished by some computational tests (power spectrum, portrait in the state space and its fractal dimension, Hurst exponent and largest Lyapunov exponent) derived from chaos theory. A high complexity dynamical trend was found. Lyapunov largest exponent test suggested bi-stability of cellular membrane resting potential during saccadic experiment. PMID:25698889

Smooth pursuitlike eye movements evoked by microstimulation in macaque nucleus reticularis tegmenti pontis.

PubMed

Yamada, T; Suzuki, D A; Yee, R D

1996-11-01

1. Smooth pursuitlike eye movements were evoked with low current microstimulation delivered to rostral portions of the nucleus reticularis tegmenti pontis (rNRTP) in alert macaques. Microstimulation sites were selected by the observation of modulations in single-cell firing rates that were correlated with periodic smoothpursuit eye movements. Current intensities ranged from 10 to 120 microA and were routinely < 40 microA. Microstimulation was delivered either in the dark with no fixation, 100 ms after a fixation target was extinguished, or during maintained fixation of a stationary or moving target. Evoked eye movements also were studied under open-loop conditions with the target image stabilized on the retina. 2. Eye movements evoked in the absence of a target rapidly accelerated to a constant velocity that was maintained for the duration of the microstimulation. Evoked eye speeds ranged from 3.7 to 23 deg/s and averaged 11 deg/s. Evoked eye speed appeared to be linearly related to initial eye position with a sensitivity to initial eye position that averaged 0.23 deg.s-1.deg-1. While some horizontal and oblique smooth eye movements were elicited, microstimulation resulted in upward eye movements in 89% of the sites. 3. Evoked eye speed was found to be dependent on microstimulation pulse frequency and current intensity. Within limits, evoked eye speed increased with increases in stimulation frequency or current intensity. For stimulation frequencies < 300-400 Hz, only smooth pursuit-like eye movements were evoked. At higher stimulation frequencies, accompanying saccades consistently were elicited. 4. Feedback of retinal image motion interacted with the evoked eye movements to decrease eye speed if the visual motion was in the opposite direction as the evoked, pursuit-like eye movements. 5. The results implicate rNRTP as part of the neuronal substrate that controls smooth-pursuit eye movements. NRTP appears to be divided functionally into a rostral, pursuit

Detecting eye movements in dynamic environments.

PubMed

Reimer, Bryan; Sodhi, Manbir

2006-11-01

To take advantage of the increasing number of in-vehicle devices, automobile drivers must divide their attention between primary (driving) and secondary (operating in-vehicle device) tasks. In dynamic environments such as driving, however, it is not easy to identify and quantify how a driver focuses on the various tasks he/she is simultaneously engaged in, including the distracting tasks. Measures derived from the driver's scan path have been used as correlates of driver attention. This article presents a methodology for analyzing eye positions, which are discrete samples of a subject's scan path, in order to categorize driver eye movements. Previous methods of analyzing eye positions recorded in a dynamic environment have relied completely on the manual identification of the focus of visual attention from a point of regard superimposed on a video of a recorded scene, failing to utilize information regarding movement structure in the raw recorded eye positions. Although effective, these methods are too time consuming to be easily used when the large data sets that would be required to identify subtle differences between drivers, under different road conditions, and with different levels of distraction are processed. The aim of the methods presented in this article are to extend the degree of automation in the processing of eye movement data by proposing a methodology for eye movement analysis that extends automated fixation identification to include smooth and saccadic movements. By identifying eye movements in the recorded eye positions, a method of reducing the analysis of scene video to a finite search space is presented. The implementation of a software tool for the eye movement analysis is described, including an example from an on-road test-driving sample.

Lateral eye-movement responses to visual stimuli.

PubMed

Wilbur, M P; Roberts-Wilbur, J

1985-08-01

The association of left lateral eye-movement with emotionality or arousal of affect and of right lateral eye-movement with cognitive/interpretive operations and functions was investigated. Participants were junior and senior students enrolled in an undergraduate course in developmental psychology. There were 37 women and 13 men, ranging from 19 to 45 yr. of age. Using videotaped lateral eye-movements of 50 participants' responses to 15 visually presented stimuli (precategorized as neutral, emotional, or intellectual), content and statistical analyses supported the association between left lateral eye-movement and emotional arousal and between right lateral eye-movement and cognitive functions. Precategorized visual stimuli included items such as a ball (neutral), gun (emotional), and calculator (intellectual). The findings are congruent with existing lateral eye-movement literature and also are additive by using visual stimuli that do not require the explicit response or implicit processing of verbal questioning.

Morning rapid eye movement sleep naps facilitate broad access to emotional semantic networks.

PubMed

Carr, Michelle; Nielsen, Tore

2015-03-01

The goal of the study was to assess semantic priming to emotion and nonemotion cue words using a novel measure of associational breadth for participants who either took rapid eye movement (REM) or nonrapid eye movement (NREM) naps or who remained awake; assess relation of priming to REM sleep consolidation and REM sleep inertia effects. The associational breadth task was applied in both a priming condition, where cue-words were signaled to be memorized prior to sleep (primed), and a nonpriming condition, where cue words were not memorized (nonprimed). Cue words were either emotional (positive, negative) or nonemotional. Participants were randomly assigned to either an awake (WAKE) or a sleep condition, which was subsequently split into NREM or REM groups depending on stage at awakening. Hospital-based sleep laboratory. Fifty-eight healthy participants (22 male) ages 18 to 35 y (Mage = 23.3 ± 4.08 y). The REM group scored higher than the NREM or WAKE groups on primed, but not nonprimed emotional cue words; the effect was stronger for positive than for negative cue words. However, REM time and percent correlated negatively with degree of emotional priming. Priming occurred for REM awakenings but not for NREM awakenings, even when the latter sleep episodes contained some REM sleep. Associational breadth may be selectively consolidated during REM sleep for stimuli that have been tagged as important for future memory retrieval. That priming decreased with REM time and was higher only for REM sleep awakenings is consistent with two explanatory REM sleep processes: REM sleep consolidation serving emotional downregulation and REM sleep inertia. © 2015 Associated Professional Sleep Societies, LLC.

21 CFR 886.1510 - Eye movement monitor.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Eye movement monitor. 886.1510 Section 886.1510...) MEDICAL DEVICES OPHTHALMIC DEVICES Diagnostic Devices § 886.1510 Eye movement monitor. (a) Identification. An eye movement monitor is an AC-powered device with an electrode intended to measure and record...

21 CFR 886.1510 - Eye movement monitor.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Eye movement monitor. 886.1510 Section 886.1510...) MEDICAL DEVICES OPHTHALMIC DEVICES Diagnostic Devices § 886.1510 Eye movement monitor. (a) Identification. An eye movement monitor is an AC-powered device with an electrode intended to measure and record...

Eye movements and abducens motoneuron behavior after cholinergic activation of the nucleus reticularis pontis caudalis.

PubMed

Márquez-Ruiz, Javier; Escudero, Miguel

2010-11-01

the aim of this work was to characterize eye movements and abducens (ABD) motoneuron behavior after cholinergic activation of the nucleus reticularis pontis caudalis (NRPC). six female adult cats were prepared for chronic recording of eye movements (using the scleral search-coil technique), electroencephalography, electromyography, ponto-geniculo-occipital (PGO) waves in the lateral geniculate nucleus, and ABD motoneuron activities after microinjections of the cholinergic agonist carbachol into the NRPC. unilateral microinjections of carbachol in the NRPC induced tonic and phasic phenomena in the oculomotor system. Tonic effects consisted of ipsiversive rotation to the injected side, convergence, and downward rotation of the eyes. Phasic effects consisted of bursts of rhythmic rapid eye movements directed contralaterally to the injected side along with PGO-like waves in the lateral geniculate and ABD nuclei. Although tonic effects were dependent on the level of drowsiness, phasic effects were always present and appeared along with normal saccades when the animal was vigilant. ABD motoneurons showed phasic activities associated with ABD PGO-like waves during bursts of rapid eye movements, and tonic and phasic activities related to eye position and velocity during alertness. the cholinergic activation of the NRPC induces oculomotor phenomena that are somewhat similar to those described during REM sleep. A precise comparison of the dynamics and timing of the eye movements further suggests that a temporal organization of both NRPCs is needed to reproduce the complexity of the oculomotor behavior during REM sleep.

Premotor neurons encode torsional eye velocity during smooth-pursuit eye movements

NASA Technical Reports Server (NTRS)

Angelaki, Dora E.; Dickman, J. David

2003-01-01

Responses to horizontal and vertical ocular pursuit and head and body rotation in multiple planes were recorded in eye movement-sensitive neurons in the rostral vestibular nuclei (VN) of two rhesus monkeys. When tested during pursuit through primary eye position, the majority of the cells preferred either horizontal or vertical target motion. During pursuit of targets that moved horizontally at different vertical eccentricities or vertically at different horizontal eccentricities, eye angular velocity has been shown to include a torsional component the amplitude of which is proportional to half the gaze angle ("half-angle rule" of Listing's law). Approximately half of the neurons, the majority of which were characterized as "vertical" during pursuit through primary position, exhibited significant changes in their response gain and/or phase as a function of gaze eccentricity during pursuit, as if they were also sensitive to torsional eye velocity. Multiple linear regression analysis revealed a significant contribution of torsional eye movement sensitivity to the responsiveness of the cells. These findings suggest that many VN neurons encode three-dimensional angular velocity, rather than the two-dimensional derivative of eye position, during smooth-pursuit eye movements. Although no clear clustering of pursuit preferred-direction vectors along the semicircular canal axes was observed, the sensitivity of VN neurons to torsional eye movements might reflect a preservation of similar premotor coding of visual and vestibular-driven slow eye movements for both lateral-eyed and foveate species.

Temporal eye movement strategies during naturalistic viewing

PubMed Central

Wang, Helena X.; Freeman, Jeremy; Merriam, Elisha P.; Hasson, Uri; Heeger, David J.

2011-01-01

The deployment of eye movements to complex spatiotemporal stimuli likely involves a variety of cognitive factors. However, eye movements to movies are surprisingly reliable both within and across observers. We exploited and manipulated that reliability to characterize observers’ temporal viewing strategies. Introducing cuts and scrambling the temporal order of the resulting clips systematically changed eye movement reliability. We developed a computational model that exhibited this behavior and provided an excellent fit to the measured eye movement reliability. The model assumed that observers searched for, found, and tracked a point-of-interest, and that this process reset when there was a cut. The model did not require that eye movements depend on temporal context in any other way, and it managed to describe eye movements consistently across different observers and two movie sequences. Thus, we found no evidence for the integration of information over long time scales (greater than a second). The results are consistent with the idea that observers employ a simple tracking strategy even while viewing complex, engaging naturalistic stimuli. PMID:22262911

Distinct eye movement patterns enhance dynamic visual acuity.

PubMed

Palidis, Dimitrios J; Wyder-Hodge, Pearson A; Fooken, Jolande; Spering, Miriam

2017-01-01

Dynamic visual acuity (DVA) is the ability to resolve fine spatial detail in dynamic objects during head fixation, or in static objects during head or body rotation. This ability is important for many activities such as ball sports, and a close relation has been shown between DVA and sports expertise. DVA tasks involve eye movements, yet, it is unclear which aspects of eye movements contribute to successful performance. Here we examined the relation between DVA and the kinematics of smooth pursuit and saccadic eye movements in a cohort of 23 varsity baseball players. In a computerized dynamic-object DVA test, observers reported the location of the gap in a small Landolt-C ring moving at various speeds while eye movements were recorded. Smooth pursuit kinematics-eye latency, acceleration, velocity gain, position error-and the direction and amplitude of saccadic eye movements were linked to perceptual performance. Results reveal that distinct eye movement patterns-minimizing eye position error, tracking smoothly, and inhibiting reverse saccades-were related to dynamic visual acuity. The close link between eye movement quality and DVA performance has important implications for the development of perceptual training programs to improve DVA.

Distinct eye movement patterns enhance dynamic visual acuity

PubMed Central

Palidis, Dimitrios J.; Wyder-Hodge, Pearson A.; Fooken, Jolande; Spering, Miriam

2017-01-01

Dynamic visual acuity (DVA) is the ability to resolve fine spatial detail in dynamic objects during head fixation, or in static objects during head or body rotation. This ability is important for many activities such as ball sports, and a close relation has been shown between DVA and sports expertise. DVA tasks involve eye movements, yet, it is unclear which aspects of eye movements contribute to successful performance. Here we examined the relation between DVA and the kinematics of smooth pursuit and saccadic eye movements in a cohort of 23 varsity baseball players. In a computerized dynamic-object DVA test, observers reported the location of the gap in a small Landolt-C ring moving at various speeds while eye movements were recorded. Smooth pursuit kinematics—eye latency, acceleration, velocity gain, position error—and the direction and amplitude of saccadic eye movements were linked to perceptual performance. Results reveal that distinct eye movement patterns—minimizing eye position error, tracking smoothly, and inhibiting reverse saccades—were related to dynamic visual acuity. The close link between eye movement quality and DVA performance has important implications for the development of perceptual training programs to improve DVA. PMID:28187157

Dopamine agonist suppression of rapid-eye-movement sleep is secondary to sleep suppression mediated via limbic structures

DOE Office of Scientific and Technical Information (OSTI.GOV)

Miletich, R.S.

The effects of pergolide, a direct dopamine receptor agonist, on sleep and wakefulness, motor behavior and /sup 3/H-spiperone specific binding in limbic structures and striatum in rats was studied. The results show that pergolide induced a biphasic dose effect, with high doses increasing wakefulness and suppressing sleep while low dose decreased wakefulness, but increased sleep. It was shown that pergolide-induced sleep suppression was blocked by ..cap alpha..-glupenthixol and pimozide, two dopamine receptor antagonists. It was further shown that pergolide merely delayed the rebound resulting from rapid-eye-movement (REM) sleep deprivation, that dopamine receptors stimulation had no direct effect on the period,more » phase or amplitude of the circadian rhythm of REM sleep propensity and that there was no alteration in the coupling of REM sleep episodes with S/sub 2/ episodes. Rapid-eye-movement sleep deprivation resulted in increased sensitivity to the pergolide-induced wakefulness stimulation and sleep suppression and pergolide-induced motor behaviors of locomotion and head bobbing. /sup 3/H-spiperone specific binding to dopamine receptors was shown to be altered by REM sleep deprivation in the subcortical limbic structures. It is concluded that the REM sleep suppressing action of dopamine receptor stimulation is secondary to sleep suppression per se and not secondary to a unique effect on the REM sleep. Further, it is suggested that the wakefulness stimulating action of dopamine receptor agonists is mediated by activation of the dopamine receptors in the terminal areas of the mesolimbocortical dopamine projection system.« less

Saccadic Eye Movements Impose a Natural Bottleneck on Visual Short-Term Memory

ERIC Educational Resources Information Center

Ohl, Sven; Rolfs, Martin

2017-01-01

Visual short-term memory (VSTM) is a crucial repository of information when events unfold rapidly before our eyes, yet it maintains only a fraction of the sensory information encoded by the visual system. Here, we tested the hypothesis that saccadic eye movements provide a natural bottleneck for the transition of fragile content in sensory memory…

Bilateral Saccadic Eye Movements and Tactile Stimulation, but Not Auditory Stimulation, Enhance Memory Retrieval

ERIC Educational Resources Information Center

Nieuwenhuis, Sander; Elzinga, Bernet M.; Ras, Priscilla H.; Berends, Floris; Duijs, Peter; Samara, Zoe; Slagter, Heleen A.

2013-01-01

Recent research has shown superior memory retrieval when participants make a series of horizontal saccadic eye movements between the memory encoding phase and the retrieval phase compared to participants who do not move their eyes or move their eyes vertically. It has been hypothesized that the rapidly alternating activation of the two hemispheres…

C9orf72 repeat expansions in rapid eye movement sleep behaviour disorder.

PubMed

Daoud, Hussein; Postuma, Ronald B; Bourassa, Cynthia V; Rochefort, Daniel; Gauthier, Maude Turcotte; Montplaisir, Jacques; Gagnon, Jean-Francois; Arnulf, Isabelle; Dauvilliers, Yves; Charley, Christelle Monaca; Inoue, Yuichi; Sasai, Taeko; Högl, Birgit; Desautels, Alex; Frauscher, Birgit; Cochen De Cock, Valérie; Rouleau, Guy A; Dion, Patrick A

2014-11-01

A large hexanucleotide repeat expansion in C9orf72 has been identified as the most common genetic cause in familial amyotrophic lateral sclerosis and frontotemporal dementia. Rapid Eye Movement Sleep Behavior Disorder (RBD) is a sleep disorder that has been strongly linked to synuclein-mediated neurodegeneration. The aim of this study was to evaluate the role of the C9orf72 expansions in the pathogenesis of RBD. We amplified the C9orf72 repeat expansion in 344 patients with RBD by a repeat-primed polymerase chain reaction assay. We identified two RBD patients carrying the C9orf72 repeat expansion. Most interestingly, these patients have the same C9orf72 associated-risk haplotype identified in 9p21-linked amyotrophic lateral sclerosis and frontotemporal dementia families. Our study enlarges the phenotypic spectrum associated with the C9orf72 hexanucleotide repeat expansions and suggests that, although rare, this expansion may play a role in the pathogenesis of RBD.

Diagnosis, disease notification, and management of rapid eye movement (REM) sleep behavior disorder.

PubMed

Shimohata, Takayoshi; Inoue, Yuichi; Hirata, Koichi

2017-02-25

Rapid eye movement (REM) sleep behavior disorder (RBD) is a parasomnia characterized by dream enactment behavior during REM sleep. It has been demonstrated that patients with idiopathic RBD are at a significantly increased risk of developing one of the α-synucleinopathies later in life, and this is called "phenoconversion". Although some physicians argue against disclosing information that could cause patients psychological stress, the patients also have a "right to know" about their own disease. Therefore, determining when and how to disclose this information, in addition to appropriate follow-up, is important. Clonazepam is the first choice of treatment for RBD associated with α-synucleinopathies. Since RBD is one of the premotor symptoms of α-synucleinopathies, and enables its early diagnosis, a combination of RBD and other examinations may contribute to the realization of a disease-modifying therapy. It is hoped that the early establishment of biomarkers could help predict the phenoconversion from RBD to α-synucleinopathies.

Eye movement identification based on accumulated time feature

NASA Astrophysics Data System (ADS)

Guo, Baobao; Wu, Qiang; Sun, Jiande; Yan, Hua

2017-06-01

Eye movement is a new kind of feature for biometrical recognition, it has many advantages compared with other features such as fingerprint, face, and iris. It is not only a sort of static characteristics, but also a combination of brain activity and muscle behavior, which makes it effective to prevent spoofing attack. In addition, eye movements can be incorporated with faces, iris and other features recorded from the face region into multimode systems. In this paper, we do an exploring study on eye movement identification based on the eye movement datasets provided by Komogortsev et al. in 2011 with different classification methods. The time of saccade and fixation are extracted from the eye movement data as the eye movement features. Furthermore, the performance analysis was conducted on different classification methods such as the BP, RBF, ELMAN and SVM in order to provide a reference to the future research in this field.

EXTRAOCULAR MUSCLE ACTIVITY, RAPID EYE MOVEMENTS, AND THE DEVELOPMENT OF ACTIVE AND QUIET SLEEP

PubMed Central

Seelke, Adele M. H.; Karlsson, Karl Æ.; Gall, Andrew J.; Blumberg, Mark S.

2008-01-01

Rapid eye movements (REMs), traditionally measured using the electrooculogram (EOG), help to characterize active sleep in adults. In early infancy, however, they are not clearly expressed. Here we measure extraocular muscle activity in infant rats at 3 days of age (P3), P8, and P14–15 in order to assess the ontogeny of REMs and their relationship with other forms of sleep-related phasic activity. We find that the causal relationship between extraocular muscle twitches and REMs strengthens during the first two postnatal weeks, reflecting increased control of the extraocular muscles over eye movements. As early as P3, however, phasic bursts of extraocular muscle twitching occur in synchrony with twitching in other muscle groups, producing waves of phasic activity interspersed with brief periods of quiescence. Surprisingly, the tone of the extraocular muscles, invisible to standard EOG measures, fluctuates in synchrony with the tone of other muscle groups; focal electrical stimulation within the dorsolateral pontine tegmentum, an area that has been shown to contain wake-on neurons in P8 rats, results in the simultaneous activation of high tone in both nuchal and extraocular muscles. Finally, when state-dependent neocortical electroencephalographic activity was observed at P14, it had already integrated fully with sleep and wakefulness as defined using electromyographic criteria alone; this finding is not consistent with the notion that active sleep in infants at this age is “half-activated.” All together, these results indicate exquisite temporal organization of sleep soon after birth and highlight the possible functional implications of homologous activational states in striated muscle and neocortex. PMID:16115214

Eye Movements During Everyday Behavior Predict Personality Traits.

PubMed

Hoppe, Sabrina; Loetscher, Tobias; Morey, Stephanie A; Bulling, Andreas

2018-01-01

Besides allowing us to perceive our surroundings, eye movements are also a window into our mind and a rich source of information on who we are, how we feel, and what we do. Here we show that eye movements during an everyday task predict aspects of our personality. We tracked eye movements of 42 participants while they ran an errand on a university campus and subsequently assessed their personality traits using well-established questionnaires. Using a state-of-the-art machine learning method and a rich set of features encoding different eye movement characteristics, we were able to reliably predict four of the Big Five personality traits (neuroticism, extraversion, agreeableness, conscientiousness) as well as perceptual curiosity only from eye movements. Further analysis revealed new relations between previously neglected eye movement characteristics and personality. Our findings demonstrate a considerable influence of personality on everyday eye movement control, thereby complementing earlier studies in laboratory settings. Improving automatic recognition and interpretation of human social signals is an important endeavor, enabling innovative design of human-computer systems capable of sensing spontaneous natural user behavior to facilitate efficient interaction and personalization.

Eye Movements During Everyday Behavior Predict Personality Traits

PubMed Central

Hoppe, Sabrina; Loetscher, Tobias; Morey, Stephanie A.; Bulling, Andreas

2018-01-01

Besides allowing us to perceive our surroundings, eye movements are also a window into our mind and a rich source of information on who we are, how we feel, and what we do. Here we show that eye movements during an everyday task predict aspects of our personality. We tracked eye movements of 42 participants while they ran an errand on a university campus and subsequently assessed their personality traits using well-established questionnaires. Using a state-of-the-art machine learning method and a rich set of features encoding different eye movement characteristics, we were able to reliably predict four of the Big Five personality traits (neuroticism, extraversion, agreeableness, conscientiousness) as well as perceptual curiosity only from eye movements. Further analysis revealed new relations between previously neglected eye movement characteristics and personality. Our findings demonstrate a considerable influence of personality on everyday eye movement control, thereby complementing earlier studies in laboratory settings. Improving automatic recognition and interpretation of human social signals is an important endeavor, enabling innovative design of human–computer systems capable of sensing spontaneous natural user behavior to facilitate efficient interaction and personalization. PMID:29713270

Effects of background motion on eye-movement information.

PubMed

Nakamura, S

1997-02-01

The effect of background stimulus on eye-movement information was investigated by analyzing the underestimation of the target velocity during pursuit eye movement (Aubert-Fleishl paradox). In the experiment, a striped pattern with various brightness contrasts and spatial frequencies was used as a background stimulus, which was moved at various velocities. Analysis showed that the perceived velocity of the pursuit target, which indicated the magnitudes of eye-movement information, decreased when the background stripes moved in the same direction as eye movement at higher velocities and increased when the background moved in the opposite direction. The results suggest that the eye-movement information varied as a linear function of the velocity of the motion of the background retinal image (optic flow). In addition, the effectiveness of optic flow on eye-movement information was determined by the attributes of the background stimulus such as the brightness contrast or the spatial frequency of the striped pattern.

EMDR Effects on Pursuit Eye Movements

PubMed Central

Kapoula, Zoi; Yang, Qing; Bonnet, Audrey; Bourtoire, Pauline; Sandretto, Jean

2010-01-01

This study aimed to objectivize the quality of smooth pursuit eye movements in a standard laboratory task before and after an Eye Movement Desensitization and Reprocessing (EMDR) session run on seven healthy volunteers. EMDR was applied on autobiographic worries causing moderate distress. The EMDR session was complete in 5 out of the 7 cases; distress measured by SUDS (Subjective Units of Discomfort Scale) decreased to a near zero value. Smooth pursuit eye movements were recorded by an Eyelink II video system before and after EMDR. For the five complete sessions, pursuit eye movement improved after their EMDR session. Notably, the number of saccade intrusions—catch-up saccades (CUS)—decreased and, reciprocally, there was an increase in the smooth components of the pursuit. Such an increase in the smoothness of the pursuit presumably reflects an improvement in the use of visual attention needed to follow the target accurately. Perhaps EMDR reduces distress thereby activating a cholinergic effect known to improve ocular pursuit. PMID:20505828

Rapid Eye Movements (REMs) and visual dream recall in both congenitally blind and sighted subjects

NASA Astrophysics Data System (ADS)

Bértolo, Helder; Mestre, Tiago; Barrio, Ana; Antona, Beatriz

2017-08-01

Our objective was to evaluate rapid eye movements (REMs) associated with visual dream recall in sighted subjects and congenital blind. During two consecutive nights polysomnographic recordings were performed at subjects home. REMs were detected by visual inspection on both EOG channels (EOG-H, EOG-V) and further classified as occurring isolated or in bursts. Dream recall was defined by the existence of a dream report. The two groups were compared using t-test and also the two-way ANOVA and a post-hoc Fisher test (for the features diagnosis (blind vs. sighted) and dream recall (yes or no) as a function of time). The average of REM awakenings per subject and the recall ability were identical in both groups. CB had a lower REM density than CS; the same applied to REM bursts and isolated eye movements. In the two-way ANOVA, REM bursts and REM density were significantly different for positive dream recall, mainly for the CB group and for diagnosis; furthermore for both features significant results were obtained for the interaction of time, recall and diagnosis; the interaction of recall and time was however, stronger. In line with previous findings the data show that blind have lower REMs density. However the ability of dream recall in congenitally blind and sighted controls is identical. In both groups visual dream recall is associated with an increase in REM bursts and density. REM bursts also show differences in the temporal profile. REM visual dream recall is associated with increased REMs activity.

Eye Carduino: A Car Control System using Eye Movements

NASA Astrophysics Data System (ADS)

Kumar, Arjun; Nagaraj, Disha; Louzardo, Joel; Hegde, Rajeshwari

2011-12-01

Modern automotive systems are rapidly becoming highly of transportation, but can be a web integrated media centre. This paper explains the implementation of a vehicle control defined and characterized by embedded electronics and software. With new technologies, the vehicle industry is facing new opportunities and also new challenges. Electronics have improved the performance of vehicles and at the same time, new more complex applications are introduced. Examples of high level applications include adaptive cruise control and electronic stability programs (ESP). Further, a modern vehicle does not have to be merely a means using only eye movements. The EyeWriter's native hardware and software work to return the co-ordinates of where the user is looking. These co-ordinates are then used to control the car. A centre-point is defined on the screen. The higher on the screen the user's gaze is, the faster the car will accelerate. Braking is done by looking below centre. Steering is done by looking left and right on the screen.

Correspondence of presaccadic activity in the monkey primary visual cortex with saccadic eye movements

PubMed Central

Supèr, Hans; van der Togt, Chris; Spekreijse, Henk; Lamme, Victor A. F.

2004-01-01

We continuously scan the visual world via rapid or saccadic eye movements. Such eye movements are guided by visual information, and thus the oculomotor structures that determine when and where to look need visual information to control the eye movements. To know whether visual areas contain activity that may contribute to the control of eye movements, we recorded neural responses in the visual cortex of monkeys engaged in a delayed figure-ground detection task and analyzed the activity during the period of oculomotor preparation. We show that ≈100 ms before the onset of visually and memory-guided saccades neural activity in V1 becomes stronger where the strongest presaccadic responses are found at the location of the saccade target. In addition, in memory-guided saccades the strength of presaccadic activity shows a correlation with the onset of the saccade. These findings indicate that the primary visual cortex contains saccade-related responses and participates in visually guided oculomotor behavior. PMID:14970334

Effects of individual differences in verbal skills on eye-movement patterns during sentence reading

PubMed Central

Kuperman, Victor; Van Dyke, Julie A.

2011-01-01

This study is a large-scale exploration of the influence that individual reading skills exert on eye-movement behavior in sentence reading. Seventy one non-college-bound 16–24 year-old speakers of English completed a battery of 18 verbal and cognitive skill assessments, and read a series of sentences as their eye movements were monitored. Statistical analyses were performed to establish what tests of reading abilities were predictive of eye-movement patterns across this population and how strong the effects were. We found that individual scores in rapid automatized naming and word identification tests (i) were the only participant variables with reliable predictivity throughout the time-course of reading; (ii) elicited effects that superceded in magnitude the effects of established predictors like word length or frequency; and (iii) strongly modulated the influence of word length and frequency on fixation times. We discuss implications of our findings for testing reading ability, as well as for research of eye-movements in reading. PMID:21709808

Eye movements evoked by electrical microstimulation of the mesencephalic reticular formation in goldfish.

PubMed

Luque, M A; Pérez-Pérez, M P; Herrero, L; Waitzman, D M; Torres, B

2006-02-01

Anatomical studies in goldfish show that the tectofugal axons provide a large number of boutons within the mesencephalic reticular formation. Electrical stimulation, reversible inactivation and cell recording in the primate central mesencephalic reticular formation have suggested that it participates in the control of rapid eye movements (saccades). Moreover, the role of this tecto-recipient area in the generation of saccadic eye movements in fish is unknown. In this study we show that the electrical microstimulation of the mesencephalic reticular formation of goldfish evoked short latency saccadic eye movements in any direction (contraversive or ipsiversive, upward or downward). Movements of the eyes were usually disjunctive. Based on the location of the sites from which eye movements were evoked and the preferred saccade direction, eye movements were divided into different groups: pure vertical saccades were mainly elicited from the rostral mesencephalic reticular formation, while oblique and pure horizontal were largely evoked from middle and caudal mesencephalic reticular formation zones. The direction and amplitude of pure vertical and horizontal saccades were unaffected by initial eye position. However the amplitude, but not the direction of most oblique saccades was systematically modified by initial eye position. At the same time, the amplitude of elicited saccades did not vary in any consistent manner along either the anteroposterior, dorsoventral or mediolateral axes (i.e. there was no topographic organization of the mesencephalic reticular formation with respect to amplitude). In addition to these groups of movements, we found convergent and goal-directed saccades evoked primarily from the anterior and posterior mesencephalic reticular formation, respectively. Finally, the metric and kinetic characteristics of saccades could be manipulated by changes in the stimulation parameters. We conclude that the mesencephalic reticular formation in goldfish shares

Eye movement-invariant representations in the human visual system.

PubMed

Nishimoto, Shinji; Huth, Alexander G; Bilenko, Natalia Y; Gallant, Jack L

2017-01-01

During natural vision, humans make frequent eye movements but perceive a stable visual world. It is therefore likely that the human visual system contains representations of the visual world that are invariant to eye movements. Here we present an experiment designed to identify visual areas that might contain eye-movement-invariant representations. We used functional MRI to record brain activity from four human subjects who watched natural movies. In one condition subjects were required to fixate steadily, and in the other they were allowed to freely make voluntary eye movements. The movies used in each condition were identical. We reasoned that the brain activity recorded in a visual area that is invariant to eye movement should be similar under fixation and free viewing conditions. In contrast, activity in a visual area that is sensitive to eye movement should differ between fixation and free viewing. We therefore measured the similarity of brain activity across repeated presentations of the same movie within the fixation condition, and separately between the fixation and free viewing conditions. The ratio of these measures was used to determine which brain areas are most likely to contain eye movement-invariant representations. We found that voxels located in early visual areas are strongly affected by eye movements, while voxels in ventral temporal areas are only weakly affected by eye movements. These results suggest that the ventral temporal visual areas contain a stable representation of the visual world that is invariant to eye movements made during natural vision.

Abnormal Fixational Eye Movements in Amblyopia.

PubMed

Shaikh, Aasef G; Otero-Millan, Jorge; Kumar, Priyanka; Ghasia, Fatema F

2016-01-01

Fixational saccades shift the foveal image to counteract visual fading related to neural adaptation. Drifts are slow eye movements between two adjacent fixational saccades. We quantified fixational saccades and asked whether their changes could be attributed to pathologic drifts seen in amblyopia, one of the most common causes of blindness in childhood. Thirty-six pediatric subjects with varying severity of amblyopia and eleven healthy age-matched controls held their gaze on a visual target. Eye movements were measured with high-resolution video-oculography during fellow eye-viewing and amblyopic eye-viewing conditions. Fixational saccades and drifts were analyzed in the amblyopic and fellow eye and compared with controls. We found an increase in the amplitude with decreased frequency of fixational saccades in children with amblyopia. These alterations in fixational eye movements correlated with the severity of their amblyopia. There was also an increase in eye position variance during drifts in amblyopes. There was no correlation between the eye position variance or the eye velocity during ocular drifts and the amplitude of subsequent fixational saccade. Our findings suggest that abnormalities in fixational saccades in amblyopia are independent of the ocular drift. This investigation of amblyopia in pediatric age group quantitatively characterizes the fixation instability. Impaired properties of fixational saccades could be the consequence of abnormal processing and reorganization of the visual system in amblyopia. Paucity in the visual feedback during amblyopic eye-viewing condition can attribute to the increased eye position variance and drift velocity.

Eye movements reduce vividness and emotionality of "flashforwards".

PubMed

Engelhard, Iris M; van den Hout, Marcel A; Janssen, Wilco C; van der Beek, Jorinde

2010-05-01

Earlier studies have shown that eye movements during retrieval of disturbing images about past events reduce their vividness and emotionality, which may be due to both tasks competing for working memory resources. This study examined whether eye movements reduce vividness and emotionality of visual distressing images about feared future events: "flashforwards". A non-clinical sample was asked to select two images of feared future events, which were self-rated for vividness and emotionality. These images were retrieved while making eye movements or without a concurrent secondary task, and then vividness and emotionality were rated again. Relative to the no-dual task condition, eye movements while thinking of future-oriented images resulted in decreased ratings of image vividness and emotional intensity. Apparently, eye movements reduce vividness and emotionality of visual images about past and future feared events. This is in line with a working memory account of the beneficial effects of eye movements, which predicts that any task that taxes working memory during retrieval of disturbing mental images will be beneficial. Copyright 2010 Elsevier Ltd. All rights reserved.

Relevance of deprivation studies in understanding rapid eye movement sleep

PubMed Central

Mehta, Rachna; Khan, Shafa; Mallick, Birendra N

2018-01-01

Rapid eye movement sleep (REMS) is a unique phenomenon essential for maintaining normal physiological processes and is expressed at least in species higher in the evolution. The basic scaffold of the neuronal network responsible for REMS regulation is present in the brainstem, which may be directly or indirectly influenced by most other physiological processes. It is regulated by the neurons in the brainstem. Various manipulations including chemical, elec-trophysiological, lesion, stimulation, behavioral, ontogenic and deprivation studies have been designed to understand REMS genesis, maintenance, physiology and functional significance. Although each of these methods has its significance and limitations, deprivation studies have contributed significantly to the overall understanding of REMS. In this review, we discuss the advantages and limitations of various methods used for REMS deprivation (REMSD) to understand neural regulation and physiological significance of REMS. Among the deprivation strategies, the flowerpot method is by far the method of choice because it is simple and convenient, exploits physiological parameter (muscle atonia) for REMSD and allows conducting adequate controls to overcome experimental limitations as well as to rule out nonspecific effects. Notwithstanding, a major criticism that the flowerpot method faces is that of perceived stress experienced by the experimental animals. Nevertheless, we conclude that like most methods, particularly for in vivo behavioral studies, in spite of a few limitations, given the advantages described above, the flowerpot method is the best method of choice for REMSD studies. PMID:29881316

Relevance of deprivation studies in understanding rapid eye movement sleep.

PubMed

Mehta, Rachna; Khan, Shafa; Mallick, Birendra N

2018-01-01

Rapid eye movement sleep (REMS) is a unique phenomenon essential for maintaining normal physiological processes and is expressed at least in species higher in the evolution. The basic scaffold of the neuronal network responsible for REMS regulation is present in the brainstem, which may be directly or indirectly influenced by most other physiological processes. It is regulated by the neurons in the brainstem. Various manipulations including chemical, elec-trophysiological, lesion, stimulation, behavioral, ontogenic and deprivation studies have been designed to understand REMS genesis, maintenance, physiology and functional significance. Although each of these methods has its significance and limitations, deprivation studies have contributed significantly to the overall understanding of REMS. In this review, we discuss the advantages and limitations of various methods used for REMS deprivation (REMSD) to understand neural regulation and physiological significance of REMS. Among the deprivation strategies, the flowerpot method is by far the method of choice because it is simple and convenient, exploits physiological parameter (muscle atonia) for REMSD and allows conducting adequate controls to overcome experimental limitations as well as to rule out nonspecific effects. Notwithstanding, a major criticism that the flowerpot method faces is that of perceived stress experienced by the experimental animals. Nevertheless, we conclude that like most methods, particularly for in vivo behavioral studies, in spite of a few limitations, given the advantages described above, the flowerpot method is the best method of choice for REMSD studies.

Variation of electroencephalographic activity during non-rapid eye movement and rapid eye movement sleep with phase of circadian melatonin rhythm in humans.

PubMed Central

Dijk, D J; Shanahan, T L; Duffy, J F; Ronda, J M; Czeisler, C A

1997-01-01

1. The circadian pacemaker regulates the timing, structure and consolidation of human sleep. The extent to which this pacemaker affects electroencephalographic (EEG) activity during sleep remains unclear. 2. To investigate this, a total of 1.22 million power spectra were computed from EEGs recorded in seven men (total, 146 sleep episodes; 9 h 20 min each) who participated in a one-month-long protocol in which the sleep-wake cycle was desynchronized from the rhythm of plasma melatonin, which is driven by the circadian pacemaker. 3. In rapid eye movement (REM) sleep a small circadian variation in EEG activity was observed. The nadir of the circadian rhythm of alpha activity (8.25-10.5 Hz) coincided with the end of the interval during which plasma melatonin values were high, i.e. close to the crest of the REM sleep rhythm. 4. In non-REM sleep, variation in EEG activity between 0.25 and 11.5 Hz was primarily dependent on prior sleep time and only slightly affected by circadian phase, such that the lowest values coincided with the phase of melatonin secretion. 5. In the frequency range of sleep spindles, high-amplitude circadian rhythms with opposite phase positions relative to the melatonin rhythm were observed. Low-frequency sleep spindle activity (12.25-13.0 Hz) reached its crest and high-frequency sleep spindle activity (14.25-15.5 Hz) reached its nadir when sleep coincided with the phase of melatonin secretion. 6. These data indicate that the circadian pacemaker induces changes in EEG activity during REM and non-REM sleep. The changes in non-REM sleep EEG spectra are dissimilar from the spectral changes induced by sleep deprivation and exhibit a close temporal association with the melatonin rhythm and the endogenous circadian phase of sleep consolidation. PMID:9457658

Analysis of EEG Related Saccadic Eye Movement

NASA Astrophysics Data System (ADS)

Funase, Arao; Kuno, Yoshiaki; Okuma, Shigeru; Yagi, Tohru

Our final goal is to establish the model for saccadic eye movement that connects the saccade and the electroencephalogram(EEG). As the first step toward this goal, we recorded and analyzed the saccade-related EEG. In the study recorded in this paper, we tried detecting a certain EEG that is peculiar to the eye movement. In these experiments, each subject was instructed to point their eyes toward visual targets (LEDs) or the direction of the sound sources (buzzers). In the control cases, the EEG was recorded in the case of no eye movemens. As results, in the visual experiments, we found that the potential of EEG changed sharply on the occipital lobe just before eye movement. Furthermore, in the case of the auditory experiments, similar results were observed. In the case of the visual experiments and auditory experiments without eye movement, we could not observed the EEG changed sharply. Moreover, when the subject moved his/her eyes toward a right-side target, a change in EEG potential was found on the right occipital lobe. On the contrary, when the subject moved his/her eyes toward a left-side target, a sharp change in EEG potential was found on the left occipital lobe.

Eye movements: The past 25 years

PubMed Central

Kowler, Eileen

2011-01-01

This article reviews the past 25 of research on eye movements (1986–2011). Emphasis is on three oculomotor behaviors: gaze control, smooth pursuit and saccades, and on their interactions with vision. Focus over the past 25 years has remained on the fundamental and classical questions: What are the mechanisms that keep gaze stable with either stationary or moving targets? How does the motion of the image on the retina affect vision? Where do we look – and why – when performing a complex task? How can the world appear clear and stable despite continual movements of the eyes? The past 25 years of investigation of these questions has seen progress and transformations at all levels due to new approaches (behavioral, neural and theoretical) aimed at studying how eye movements cope with real-world visual and cognitive demands. The work has led to a better understanding of how prediction, learning and attention work with sensory signals to contribute to the effective operation of eye movements in visually rich environments. PMID:21237189

Abnormal Fixational Eye Movements in Amblyopia

PubMed Central

Shaikh, Aasef G.; Otero-Millan, Jorge; Kumar, Priyanka; Ghasia, Fatema F.

2016-01-01

Purpose Fixational saccades shift the foveal image to counteract visual fading related to neural adaptation. Drifts are slow eye movements between two adjacent fixational saccades. We quantified fixational saccades and asked whether their changes could be attributed to pathologic drifts seen in amblyopia, one of the most common causes of blindness in childhood. Methods Thirty-six pediatric subjects with varying severity of amblyopia and eleven healthy age-matched controls held their gaze on a visual target. Eye movements were measured with high-resolution video-oculography during fellow eye-viewing and amblyopic eye-viewing conditions. Fixational saccades and drifts were analyzed in the amblyopic and fellow eye and compared with controls. Results We found an increase in the amplitude with decreased frequency of fixational saccades in children with amblyopia. These alterations in fixational eye movements correlated with the severity of their amblyopia. There was also an increase in eye position variance during drifts in amblyopes. There was no correlation between the eye position variance or the eye velocity during ocular drifts and the amplitude of subsequent fixational saccade. Our findings suggest that abnormalities in fixational saccades in amblyopia are independent of the ocular drift. Discussion This investigation of amblyopia in pediatric age group quantitatively characterizes the fixation instability. Impaired properties of fixational saccades could be the consequence of abnormal processing and reorganization of the visual system in amblyopia. Paucity in the visual feedback during amblyopic eye-viewing condition can attribute to the increased eye position variance and drift velocity. PMID:26930079

Kinematics of Visually-Guided Eye Movements

PubMed Central

Hess, Bernhard J. M.; Thomassen, Jakob S.

2014-01-01

One of the hallmarks of an eye movement that follows Listing’s law is the half-angle rule that says that the angular velocity of the eye tilts by half the angle of eccentricity of the line of sight relative to primary eye position. Since all visually-guided eye movements in the regime of far viewing follow Listing’s law (with the head still and upright), the question about its origin is of considerable importance. Here, we provide theoretical and experimental evidence that Listing’s law results from a unique motor strategy that allows minimizing ocular torsion while smoothly tracking objects of interest along any path in visual space. The strategy consists in compounding conventional ocular rotations in meridian planes, that is in horizontal, vertical and oblique directions (which are all torsion-free) with small linear displacements of the eye in the frontal plane. Such compound rotation-displacements of the eye can explain the kinematic paradox that the fixation point may rotate in one plane while the eye rotates in other planes. Its unique signature is the half-angle law in the position domain, which means that the rotation plane of the eye tilts by half-the angle of gaze eccentricity. We show that this law does not readily generalize to the velocity domain of visually-guided eye movements because the angular eye velocity is the sum of two terms, one associated with rotations in meridian planes and one associated with displacements of the eye in the frontal plane. While the first term does not depend on eye position the second term does depend on eye position. We show that compounded rotation - displacements perfectly predict the average smooth kinematics of the eye during steady- state pursuit in both the position and velocity domain. PMID:24751602

Obstructive sleep apnea related to rapid-eye-movement or non-rapid-eye-movement sleep: comparison of demographic, anthropometric, and polysomnographic features

PubMed Central

Sunnetcioglu, Aysel; Sertogullarından, Bunyamin; Ozbay, Bulent; Gunbatar, Hulya; Ekin, Selami

2016-01-01

Objective : To determine whether there are significant differences between rapid-eye-movement (REM)-related obstructive sleep apnea (OSA) and non-REM (NREM)-related OSA, in terms of the demographic, anthropometric, and polysomnographic characteristics of the subjects. Methods : This was a retrospective study of 110 patients (75 males) with either REM-related OSA (n = 58) or NREM-related OSA (n = 52). To define REM-related and NREM-related OSA, we used a previously established criterion, based on the apnea-hypopnea index (AHI): AHI-REM/AHI-NREM ratio > 2 and ≤ 2, respectively. Results : The mean age of the patients with REM-related OSA was 49.5 ± 11.9 years, whereas that of the patients with NREM-related OSA was 49.2 ± 12.6 years. The overall mean AHI (all sleep stages combined) was significantly higher in the NREM-related OSA group than in the REM-related OSA group (38.6 ± 28.2 vs. 14.8 ± 9.2; p < 0.05). The mean AHI in the supine position (s-AHI) was also significantly higher in the NREM-related OSA group than in the REM-related OSA group (49.0 ± 34.3 vs. 18.8 ± 14.9; p < 0.0001). In the NREM-related OSA group, the s-AHI was higher among the men. In both groups, oxygen desaturation was more severe among the women. We found that REM-related OSA was more common among the patients with mild-to-moderate OSA, whereas NREM-related OSA was more common among those with severe OSA. Conclusions : We found that the severity of NREM-related OSA was associated mainly with s-AHI. Our findings suggest that the s-AHI has a more significant effect on the severity of OSA than does the AHI-REM. When interpreting OSA severity and choosing among treatment modalities, physicians should take into consideration the sleep stage and the sleep posture. PMID:26982041

Variability of eye movements when viewing dynamic natural scenes.

PubMed

Dorr, Michael; Martinetz, Thomas; Gegenfurtner, Karl R; Barth, Erhardt

2010-08-26

How similar are the eye movement patterns of different subjects when free viewing dynamic natural scenes? We collected a large database of eye movements from 54 subjects on 18 high-resolution videos of outdoor scenes and measured their variability using the Normalized Scanpath Saliency, which we extended to the temporal domain. Even though up to about 80% of subjects looked at the same image region in some video parts, variability usually was much greater. Eye movements on natural movies were then compared with eye movements in several control conditions. "Stop-motion" movies had almost identical semantic content as the original videos but lacked continuous motion. Hollywood action movie trailers were used to probe the upper limit of eye movement coherence that can be achieved by deliberate camera work, scene cuts, etc. In a "repetitive" condition, subjects viewed the same movies ten times each over the course of 2 days. Results show several systematic differences between conditions both for general eye movement parameters such as saccade amplitude and fixation duration and for eye movement variability. Most importantly, eye movements on static images are initially driven by stimulus onset effects and later, more so than on continuous videos, by subject-specific idiosyncrasies; eye movements on Hollywood movies are significantly more coherent than those on natural movies. We conclude that the stimuli types often used in laboratory experiments, static images and professionally cut material, are not very representative of natural viewing behavior. All stimuli and gaze data are publicly available at http://www.inb.uni-luebeck.de/tools-demos/gaze.

Benzodiazepines impair smooth pursuit eye movements.

PubMed Central

Bittencourt, P R; Wade, P; Smith, A T; Richens, A

1983-01-01

Five healthy male volunteers received single oral doses of 10 mg diazepam, 20 mg temazepam and placebo, in a double-blind, randomised fashion. Smooth pursuit eye movement velocity and serum benzodiazepine concentration were measured before and after at 0.5,1,1.5,2,3,4,6,9 and 12 h after administration of the treatments. Significant decrease in smooth pursuit eye movement velocity as compared to placebo was observed between 0.5-2 h after temazepam, and between 1-2 h after diazepam. Smooth pursuit eye movement velocity was log-linearly correlated with serum temazepam and diazepam concentration. The results demonstrate the relationship between serum benzodiazepine concentration and its effect on an objective measure of oculomotor performance. PMID:6133544

Substance P and the neurokinin-1 receptor regulate electroencephalogram non-rapid eye movement sleep slow-wave activity locally

PubMed Central

Zielinski, Mark R.; Karpova, Svetlana A.; Yang, Xiaomei; Gerashchenko, Dmitry

2014-01-01

The neuropeptide substance P is an excitatory neurotransmitter produced by various cells including neurons and microglia that is involved in regulating inflammation and cerebral blood flow—functions that affect sleep and slow-wave activity (SWA). Substance P is the major ligand for the neurokinin-1 receptor (NK-1R), which is found throughout the brain including the cortex. The NK-1R is found on sleep-active cortical neurons expressing neuronal nitric oxide synthase whose activity is associated with SWA. We determined the effects of local cortical administration of a NK-1R agonist (substance P-fragment 1, 7) and a NK-1R antagonist (CP96345) on sleep and SWA in mice. The NK-1R agonist significantly enhanced SWA for several hours when applied locally to the cortex of the ipsilateral hemisphere as the electroencephalogram (EEG) electrode but not after application to the contralateral hemisphere when compared to saline vehicle control injections. In addition, a significant compensatory reduction in SWA was found after the NK-1R agonist-induced enhancements in SWA. Conversely, injections of the NK-1R antagonist into the cortex of the ipsilateral hemisphere of the EEG electrode attenuated SWA compared to vehicle injections but this effect was not found after injections of the NK-1R antagonist into contralateral hemisphere as the EEG electrode. Non-rapid eye movement sleep and rapid eye movement sleep duration responses after NK-1R agonist and antagonist injections were not significantly different from the responses to the vehicle. Our findings indicate that the substance P and the NK-1R are involved in regulating SWA locally. PMID:25301750

Eye Movements in Darkness Modulate Self-Motion Perception.

PubMed

Clemens, Ivar Adrianus H; Selen, Luc P J; Pomante, Antonella; MacNeilage, Paul R; Medendorp, W Pieter

2017-01-01

During self-motion, humans typically move the eyes to maintain fixation on the stationary environment around them. These eye movements could in principle be used to estimate self-motion, but their impact on perception is unknown. We had participants judge self-motion during different eye-movement conditions in the absence of full-field optic flow. In a two-alternative forced choice task, participants indicated whether the second of two successive passive lateral whole-body translations was longer or shorter than the first. This task was used in two experiments. In the first ( n = 8), eye movements were constrained differently in the two translation intervals by presenting either a world-fixed or body-fixed fixation point or no fixation point at all (allowing free gaze). Results show that perceived translations were shorter with a body-fixed than a world-fixed fixation point. A linear model indicated that eye-movement signals received a weight of ∼25% for the self-motion percept. This model was independently validated in the trials without a fixation point (free gaze). In the second experiment ( n = 10), gaze was free during both translation intervals. Results show that the translation with the larger eye-movement excursion was judged more often to be larger than chance, based on an oculomotor choice probability analysis. We conclude that eye-movement signals influence self-motion perception, even in the absence of visual stimulation.

Flurbiprofen in rapid eye movement sleep deprivation induced hyperalgesia.

PubMed

Gürel, Elif Ezgi; Ural, Keremcan; Öztürk, Gülnur; Öztürk, Levent

2014-04-10

Rapid eye movement (REM) sleep deprivation induces hyperalgesia in healthy rats. Here, we evaluated the effects of flurbiprofen, an anti-inflammatory and neuroprotective agent, on the increased thermal responses observed in REM sleep deprived rats. Forty female rats were divided into four groups following 96-hour REM sleep deprivation: intraperitoneal injections of placebo, and flurbiprofen 5 mg/kg, 15 mg/kg and 40 mg/kg were made in CONT (n=10), FBP5, FBP15 and FBP40 groups respectively. Pain threshold measurements were performed three times at baseline (0.hour), at the end of REM sleep deprivation (96.hour) and at 1 h after injections (97.hour) by hot plate and tail-flick tests. REM sleep deprivation induced a significant decrease in pain thresholds of all rats (hotplate: 0.hour vs 96.hour, 9.75±2.85 vs 5.10±2.02, p<0.001; tail flick: 0.hour vs 96.hour, 11.92±4.62 vs 7.92±5.15, p<0.001). Flurbiprofen in 15 mg/kg and 40 mg/kg doses significantly improved pain tolerance measured by tail flick test (tail flick in FBP15 and FBP40 groups: 96.hour vs 97.hour, 7.01±4.97 vs 8.34±3.61 and 5.06±1.57 vs 7.04±2.49, p<0.05 for both). 96 h of REM sleep deprivation resulted in reduced pain thresholds in both hot plate and tail flick tests. Flurbiprofen was used for the first time in a rat model of REM sleep deprivation, and it provided anti-nociceptive effects in 15 mg/kg and 40 mg/kg doses. Flurbiprofen may have the potential for treatment of painful syndromes accompanying insomnia or sleep loss. Copyright © 2014 Elsevier Inc. All rights reserved.

Activation of inactivation process initiates rapid eye movement sleep.

PubMed

Mallick, Birendra Nath; Singh, Abhishek; Khanday, Mudasir Ahmad

2012-06-01

Interactions among REM-ON and REM-OFF neurons form the basic scaffold for rapid eye movement sleep (REMS) regulation; however, precise mechanism of their activation and cessation, respectively, was unclear. Locus coeruleus (LC) noradrenalin (NA)-ergic neurons are REM-OFF type and receive GABA-ergic inputs among others. GABA acts postsynaptically on the NA-ergic REM-OFF neurons in the LC and presynaptically on the latter's projection terminals and modulates NA-release on the REM-ON neurons. Normally during wakefulness and non-REMS continuous release of NA from the REM-OFF neurons, which however, is reduced during the latter phase, inhibits the REM-ON neurons and prevents REMS. At this stage GABA from substantia nigra pars reticulate acting presynaptically on NA-ergic terminals on REM-ON neurons withdraws NA-release causing the REM-ON neurons to escape inhibition and being active, may be even momentarily. A working-model showing neurochemical-map explaining activation of inactivation process, showing contribution of GABA-ergic presynaptic inhibition in withdrawing NA-release and dis-inhibition induced activation of REM-ON neurons, which in turn activates other GABA-ergic neurons and shutting-off REM-OFF neurons for the initiation of REMS-generation has been explained. Our model satisfactorily explains yet unexplained puzzles (i) why normally REMS does not appear during waking, rather, appears following non-REMS; (ii) why cessation of LC-NA-ergic-REM-OFF neurons is essential for REMS-generation; (iii) factor(s) which does not allow cessation of REM-OFF neurons causes REMS-loss; (iv) the association of changes in levels of GABA and NA in the brain during REMS and its deprivation and associated symptoms; v) why often dreams are associated with REMS. Copyright © 2012 Elsevier Ltd. All rights reserved.

Evaluating camouflage design using eye movement data.

PubMed

Lin, Chiuhsiang Joe; Chang, Chi-Chan; Lee, Yung-Hui

2014-05-01

This study investigates the characteristics of eye movements during a camouflaged target search task. Camouflaged targets were randomly presented on two natural landscapes. The performance of each camouflage design was assessed by target detection hit rate, detection time, number of fixations on display, first saccade amplitude to target, number of fixations on target, fixation duration on target, and subjective ratings of search task difficulty. The results showed that the camouflage patterns could significantly affect the eye-movement behavior, especially first saccade amplitude and fixation duration, and the findings could be used to increase the sensitivity of the camouflage assessment. We hypothesized that the assessment could be made with regard to the differences in detectability and discriminability of the camouflage patterns. These could explain less efficient search behavior in eye movements. Overall, data obtained from eye movements can be used to significantly enhance the interpretation of the effects of different camouflage design. Copyright © 2013 Elsevier Ltd and The Ergonomics Society. All rights reserved.

The inappropriate occurrence of rapid eye movement sleep in narcolepsy is not due to a defect in homeostatic regulation of rapid eye movement sleep.

PubMed

Roman, Alexis; Meftah, Soraya; Arthaud, Sébastien; Luppi, Pierre-Hervé; Peyron, Christelle

2018-06-01

Narcolepsy type 1 is a disabling disorder with four primary symptoms: excessive-daytime-sleepiness, cataplexy, hypnagogic hallucinations, and sleep paralysis. The later three symptoms together with a short rapid eye movement (REM) sleep latency have suggested impairment in REM sleep homeostatic regulation with an enhanced propensity for (i.e. tendency to enter) REM sleep. To test this hypothesis, we challenged REM sleep homeostatic regulation in a recognized model of narcolepsy, the orexin knock-out (Orex-KO) mice and their wild-type (WT) littermates. We first performed 48 hr of REM sleep deprivation using the classic small-platforms-over-water method. We found that narcoleptic mice are similarly REM sleep deprived to WT mice. Although they had shorter sleep latency, Orex-KO mice recovered similarly to WT during the following 10 hr of recovery. Interestingly, Orex-KO mice also had cataplexy episodes immediately after REM sleep deprivation, anticipating REM sleep rebound, at a time of day when cataplexy does not occur in baseline condition. We then evaluated REM sleep propensity using our new automated method of deprivation that performs a specific and efficient REM sleep deprivation. We showed that REM sleep propensity is similar during light phase in Orex-KO and WT mice. However, during the dark phase, REM sleep propensity was not suppressed in Orex-KO mice when hypocretin/orexin neuropeptides are normally released. Altogether our data suggest that in addition to the well-known wake-promoting role of hypocretin/orexin, these neuropeptides would also suppress REM sleep. Therefore, hypocretin/orexin deficiency would facilitate the occurrence of REM sleep at any time of day in an opportunistic manner as seen in human narcolepsy.

Effects of background stimulation upon eye-movement information.

PubMed

Nakamura, S

1996-04-01

To investigate the effects of background stimulation upon eye-movement information (EMI), the perceived deceleration of the target motion during pursuit eye movement (Aubert-Fleishl paradox) was analyzed. In the experiment, a striped pattern was used as a background stimulus with various brightness contrasts and spatial frequencies for serially manipulating the attributions of the background stimulus. Analysis showed that the retinal-image motion of the background stimulus (optic flow) affected eye-movement information and that the effects of optic flow became stronger when high contrast and low spatial frequency stripes were presented as the background stimulus. In conclusion, optic flow is one source of eye-movement information in determining real object motion, and the effectiveness of optic flow depends on the attributes of the background stimulus.

Eye Movements in Darkness Modulate Self-Motion Perception

PubMed Central

Pomante, Antonella

2017-01-01

Abstract During self-motion, humans typically move the eyes to maintain fixation on the stationary environment around them. These eye movements could in principle be used to estimate self-motion, but their impact on perception is unknown. We had participants judge self-motion during different eye-movement conditions in the absence of full-field optic flow. In a two-alternative forced choice task, participants indicated whether the second of two successive passive lateral whole-body translations was longer or shorter than the first. This task was used in two experiments. In the first (n = 8), eye movements were constrained differently in the two translation intervals by presenting either a world-fixed or body-fixed fixation point or no fixation point at all (allowing free gaze). Results show that perceived translations were shorter with a body-fixed than a world-fixed fixation point. A linear model indicated that eye-movement signals received a weight of ∼25% for the self-motion percept. This model was independently validated in the trials without a fixation point (free gaze). In the second experiment (n = 10), gaze was free during both translation intervals. Results show that the translation with the larger eye-movement excursion was judged more often to be larger than chance, based on an oculomotor choice probability analysis. We conclude that eye-movement signals influence self-motion perception, even in the absence of visual stimulation. PMID:28144623

Advances in Relating Eye Movements and Cognition

ERIC Educational Resources Information Center

Hayhoe, Mary M.

2004-01-01

Measurement of eye movements is a powerful tool for investigating perceptual and cognitive function in both infants and adults. Straightforwardly, eye movements provide a multifaceted measure of performance. For example, the location of fixations, their duration, time of occurrence, and accuracy all are potentially revealing and often allow…

Tumor Necrosis Factor Antagonism Normalizes Rapid Eye Movement Sleep in Alcohol Dependence

PubMed Central

Irwin, Michael R.; Olmstead, Richard; Valladares, Edwin M.; Breen, Elizabeth Crabb; Ehlers, Cindy L.

2009-01-01

Background In alcohol dependence, markers of inflammation are associated with increases in rapid eye movement (REM) sleep, which is thought to be a prognostic indicator of alcohol relapse. This study was undertaken to test whether blockade of biologically active tumor necrosis factor-α (TNF-α) normalizes REM sleep in alcohol-dependent adults. Methods In a randomized, placebo-controlled, double-blind, crossover trial, 18 abstinent alcohol-dependent male adults received a single dose of etanercept (25 mg) versus placebo in a counterbalanced order. Polysomnographic sleep was measured at baseline and for 3 nights after the acute dose of etanercept or placebo. Results Compared with placebo, administration of etanercept produced significant decreases in the amount and percentage of REM sleep. Decreases in REM sleep were robust and approached low levels typically found in age-comparable control subjects. Individual differences in biologically active drug as indexed by circulating levels of soluble tumor necrosis factor receptor II negatively correlated with the percentage of REM sleep. Conclusions Pharmacologic neutralization of TNF-α activity is associated with significant reductions in REM sleep in abstinent alcohol-dependent patients. These data suggest that circulating levels of TNF-α may have a physiologic role in the regulation of REM sleep in humans. PMID:19185287

The Trajectories of Saccadic Eye Movements.

ERIC Educational Resources Information Center

Bahill, A. Terry; Stark, Lawrence

1979-01-01

Investigates the trajectories of saccadic eye movements, the control signals of the eye, and nature of the mechanisms that generate them, using the techniques of bioengineering in collecting the data. (GA)

Binocular eye movement control and motion perception: what is being tracked?

PubMed

van der Steen, Johannes; Dits, Joyce

2012-10-19

We investigated under what conditions humans can make independent slow phase eye movements. The ability to make independent movements of the two eyes generally is attributed to few specialized lateral eyed animal species, for example chameleons. In our study, we showed that humans also can move the eyes in different directions. To maintain binocular retinal correspondence independent slow phase movements of each eye are produced. We used the scleral search coil method to measure binocular eye movements in response to dichoptically viewed visual stimuli oscillating in orthogonal direction. Correlated stimuli led to orthogonal slow eye movements, while the binocularly perceived motion was the vector sum of the motion presented to each eye. The importance of binocular fusion on independency of the movements of the two eyes was investigated with anti-correlated stimuli. The perceived global motion pattern of anti-correlated dichoptic stimuli was perceived as an oblique oscillatory motion, as well as resulted in a conjugate oblique motion of the eyes. We propose that the ability to make independent slow phase eye movements in humans is used to maintain binocular retinal correspondence. Eye-of-origin and binocular information are used during the processing of binocular visual information, and it is decided at an early stage whether binocular or monocular motion information and independent slow phase eye movements of each eye are produced during binocular tracking.

Binocular Eye Movement Control and Motion Perception: What Is Being Tracked?

PubMed Central

van der Steen, Johannes; Dits, Joyce

2012-01-01

Purpose. We investigated under what conditions humans can make independent slow phase eye movements. The ability to make independent movements of the two eyes generally is attributed to few specialized lateral eyed animal species, for example chameleons. In our study, we showed that humans also can move the eyes in different directions. To maintain binocular retinal correspondence independent slow phase movements of each eye are produced. Methods. We used the scleral search coil method to measure binocular eye movements in response to dichoptically viewed visual stimuli oscillating in orthogonal direction. Results. Correlated stimuli led to orthogonal slow eye movements, while the binocularly perceived motion was the vector sum of the motion presented to each eye. The importance of binocular fusion on independency of the movements of the two eyes was investigated with anti-correlated stimuli. The perceived global motion pattern of anti-correlated dichoptic stimuli was perceived as an oblique oscillatory motion, as well as resulted in a conjugate oblique motion of the eyes. Conclusions. We propose that the ability to make independent slow phase eye movements in humans is used to maintain binocular retinal correspondence. Eye-of-origin and binocular information are used during the processing of binocular visual information, and it is decided at an early stage whether binocular or monocular motion information and independent slow phase eye movements of each eye are produced during binocular tracking. PMID:22997286

Incremental comprehension of pitch relationships in written music: Evidence from eye movements.

PubMed

Hadley, Lauren V; Sturt, Patrick; Eerola, Tuomas; Pickering, Martin J

2017-03-17

To investigate how proficient pianists comprehend pitch relationships in written music when they first encounter it we conducted two experiments in which proficient pianists' eyes were tracked while they read and played single-line melodies. In Experiment 1, participants played at their own speed; in Experiment 2 they played with an external metronome. The melodies were either congruent or anomalous, with the anomaly involving one bar being shifted in pitch to alter the implied harmonic structure (e.g., non-resolution of a dominant). In both experiments, anomaly led to rapid disruption in participants' eye-movements in terms of regressions from the target bar, indicating that pianists process written pitch relationships online. This is particularly striking because in musical sight-reading eye movement behaviour is constrained by the concurrent performance. Both experiments also showed that anomaly induced pupil dilation. Together these results indicate that proficient pianists rapidly integrate the music that they read into the prior context, and that anomalies in terms of pitch relationships lead to processing difficulty. These findings parallel those of text reading, suggesting that structural processing involves similar constraints across domains.

ECEM (eye closure eye movements): integrating aspects of EMDR with hypnosis for treatment of trauma.

PubMed

Hollander, H E; Bender, S S

2001-01-01

The paper addresses distinctions between hypnotic interventions and Eye Movement Desensitizing and Reprocessing (EMDR) and discusses their effect on persons who have symptoms of Posttraumatic Stress Disorder (PTSD). Eye movements in hypnosis and EMDR are considered in terms of the different ways they may affect responses in treatment. A treatment intervention within hypnosis called ECEM (Eye Closure, Eye Movements) is described. ECEM can be used for patients with histories of trauma who did not benefit adequately from either interventions in hypnosis or the EMDR treatment protocol used separately. In ECEM the eye movement variable of EMDR is integrated within a hypnosis protocol to enhance benefits of hypnosis and reduce certain risks of EMDR.

Smooth pursuit eye movements and schizophrenia: literature review.

PubMed

Franco, J G; de Pablo, J; Gaviria, A M; Sepúlveda, E; Vilella, E

2014-09-01

To review the scientific literature about the relationship between impairment on smooth pursuit eye movements and schizophrenia. Narrative review that includes historical articles, reports about basic and clinical investigation, systematic reviews, and meta-analysis on the topic. Up to 80% of schizophrenic patients have impairment of smooth pursuit eye movements. Despite the diversity of test protocols, 65% of patients and controls are correctly classified by their overall performance during this pursuit. The smooth pursuit eye movements depend on the ability to anticipate the target's velocity and the visual feedback, as well as on learning and attention. The neuroanatomy implicated in smooth pursuit overlaps to some extent with certain frontal cortex zones associated with some clinical and neuropsychological characteristics of the schizophrenia, therefore some specific components of smooth pursuit anomalies could serve as biomarkers of the disease. Due to their sedative effect, antipsychotics have a deleterious effect on smooth pursuit eye movements, thus these movements cannot be used to evaluate the efficacy of the currently available treatments. Standardized evaluation of smooth pursuit eye movements on schizophrenia will allow to use specific aspects of that pursuit as biomarkers for the study of its genetics, psychopathology, or neuropsychology. Copyright © 2013 Sociedad Española de Oftalmología. Published by Elsevier Espana. All rights reserved.

Saccadic eye movement applications for psychiatric disorders

PubMed Central

Bittencourt, Juliana; Velasques, Bruna; Teixeira, Silmar; Basile, Luis F; Salles, José Inácio; Nardi, Antonio Egídio; Budde, Henning; Cagy, Mauricio; Piedade, Roberto; Ribeiro, Pedro

2013-01-01

Objective The study presented here analyzed the patterns of relationship between oculomotor performance and psychopathology, focusing on depression, bipolar disorder, schizophrenia, attention-deficit hyperactivity disorder, and anxiety disorder. Methods Scientific articles published from 1967 to 2013 in the PubMed/Medline, ISI Web of Knowledge, Cochrane, and SciELO databases were reviewed. Results Saccadic eye movement appears to be heavily involved in psychiatric diseases covered in this review via a direct mechanism. The changes seen in the execution of eye movement tasks in patients with psychopathologies of various studies confirm that eye movement is associated with the cognitive and motor system. Conclusion Saccadic eye movement changes appear to be heavily involved in the psychiatric disorders covered in this review and may be considered a possible marker of some disorders. The few existing studies that approach the topic demonstrate a need to improve the experimental paradigms, as well as the methods of analysis. Most of them report behavioral variables (latency/reaction time), though electrophysiological measures are absent. PMID:24072973

CUE: counterfeit-resistant usable eye movement-based authentication via oculomotor plant characteristics and complex eye movement patterns

NASA Astrophysics Data System (ADS)

Komogortsev, Oleg V.; Karpov, Alexey; Holland, Corey D.

2012-06-01

The widespread use of computers throughout modern society introduces the necessity for usable and counterfeit-resistant authentication methods to ensure secure access to personal resources such as bank accounts, e-mail, and social media. Current authentication methods require tedious memorization of lengthy pass phrases, are often prone to shouldersurfing, and may be easily replicated (either by counterfeiting parts of the human body or by guessing an authentication token based on readily available information). This paper describes preliminary work toward a counterfeit-resistant usable eye movement-based (CUE) authentication method. CUE does not require any passwords (improving the memorability aspect of the authentication system), and aims to provide high resistance to spoofing and shoulder-surfing by employing the combined biometric capabilities of two behavioral biometric traits: 1) oculomotor plant characteristics (OPC) which represent the internal, non-visible, anatomical structure of the eye; 2) complex eye movement patterns (CEM) which represent the strategies employed by the brain to guide visual attention. Both OPC and CEM are extracted from the eye movement signal provided by an eye tracking system. Preliminary results indicate that the fusion of OPC and CEM traits is capable of providing a 30% reduction in authentication error when compared to the authentication accuracy of individual traits.

Is Mixed Apnea Associated with Non-Rapid Eye Movement Sleep a Reversible Compensatory Sign of Heart Failure?

PubMed Central

Korostovtseva, Lyudmila; Sazonova, Yulia; Zvartau, Nadezhda; Semenov, Andrew; Nepran, Viktoriya; Bochkarev, Mikhail; Nikolaev, German; Mitrofanova, Lyubov; Sviryaev, Yurii; Gordeev, Mikhail; Konradi, Aleksandra

2015-01-01

Patient: Male, 24 Final Diagnosis: Dilated cardiomyopathy Symptoms: Biventricular heart failure • sleep apnea Medication: — Clinical Procedure: Heart transplantation Specialty: Cardiology Objective: Unusual or unexpected effect of treatment Background: Sleep-disordered breathing is common in heart failure (HF), and prolonged circulation time and diminished pulmonary volume are considered the main possible causes of sleep apnea in these patients. However, the impact and interrelation between sleep apnea and HF development are unclear. We report the case of a patient with complete elimination of non-rapid-eye-movement (NREM) sleep-associated mixed apnea in HF after heart transplantation. Case Report: After unsuccessful 12-month conventional treatment with abrupt exacerbation of biventricular HF IV class (according to New York Heart Association Functional Classification), a 26-year-old man was admitted to the hospital. Based on a comprehensive examination including endomyocardial biopsy, dilated cardiomyopathy was diagnosed. Heart transplantation was considered the only possible treatment strategy. Polysomnography showed severe NREM sleep-associated mixed sleep apnea [apnea-hypopnea index 43/h, in rapid eye movement (REM) sleep 3.7/h, in NREM sleep 56.4/h, mean SatO2 93.9%], and periodic breathing. One-month post-transplantation polysomnography did not show sleep-disordered breathing (apnea-hypopnea index 1.0/h; in REM sleep − 2.8/h, in NREM sleep 0.5/h, mean SatO2 97.5%). The patient was discharged from the hospital in improved condition. Conclusions: NREM sleep-associated mixed apnea occurring in severe systolic HF due to dilated cardiomyopathy might be reversible in case of successful HF treatment. We suggest that mixed sleep apnea strongly associated with NREM sleep occurs in HF, when the brain centers regulating ventilation are intact, and successful HF compensation might be highly effective regarding sleep-breathing disorders without non

A unified dynamic neural field model of goal directed eye movements

NASA Astrophysics Data System (ADS)

Quinton, J. C.; Goffart, L.

2018-01-01

Primates heavily rely on their visual system, which exploits signals of graded precision based on the eccentricity of the target in the visual field. The interactions with the environment involve actively selecting and focusing on visual targets or regions of interest, instead of contemplating an omnidirectional visual flow. Eye-movements specifically allow foveating targets and track their motion. Once a target is brought within the central visual field, eye-movements are usually classified into catch-up saccades (jumping from one orientation or fixation to another) and smooth pursuit (continuously tracking a target with low velocity). Building on existing dynamic neural field equations, we introduce a novel model that incorporates internal projections to better estimate the current target location (associated to a peak of activity). Such estimate is then used to trigger an eye movement, leading to qualitatively different behaviours depending on the dynamics of the whole oculomotor system: (1) fixational eye-movements due to small variations in the weights of projections when the target is stationary, (2) interceptive and catch-up saccades when peaks build and relax on the neural field, (3) smooth pursuit when the peak stabilises near the centre of the field, the system reaching a fixed point attractor. Learning is nevertheless required for tracking a rapidly moving target, and the proposed model thus replicates recent results in the monkey, in which repeated exercise permits the maintenance of the target within in the central visual field at its current (here-and-now) location, despite the delays involved in transmitting retinal signals to the oculomotor neurons.

Eye Movement Indices in the Study of Depressive Disorder.

PubMed

Li, Yu; Xu, Yangyang; Xia, Mengqing; Zhang, Tianhong; Wang, Junjie; Liu, Xu; He, Yongguang; Wang, Jijun

2016-12-25

Impaired cognition is one of the most common core symptoms of depressive disorder. Eye movement testing mainly reflects patients' cognitive functions, such as cognition, memory, attention, recognition, and recall. This type of testing has great potential to improve theories related to cognitive functioning in depressive episodes as well as potential in its clinical application. This study investigated whether eye movement indices of patients with unmedicated depressive disorder were abnormal or not, as well as the relationship between these indices and mental symptoms. Sixty patients with depressive disorder and sixty healthy controls (who were matched by gender, age and years of education) were recruited, and completed eye movement tests including three tasks: fixation task, saccade task and free-view task. The EyeLink desktop eye tracking system was employed to collect eye movement information, and analyze the eye movement indices of the three tasks between the two groups. (1) In the fixation task, compared to healthy controls, patients with depressive disorder showed more fixations, shorter fixation durations, more saccades and longer saccadic lengths; (2) In the saccade task, patients with depressive disorder showed longer anti-saccade latencies and smaller anti-saccade peak velocities; (3) In the free-view task, patients with depressive disorder showed fewer saccades and longer mean fixation durations; (4) Correlation analysis showed that there was a negative correlation between the pro-saccade amplitude and anxiety symptoms, and a positive correlation between the anti-saccade latency and anxiety symptoms. The depression symptoms were negatively correlated with fixation times, saccades, and saccadic paths respectively in the free-view task; while the mean fixation duration and depression symptoms showed a positive correlation. Compared to healthy controls, patients with depressive disorder showed significantly abnormal eye movement indices. In addition

Eye movement abnormalities in hermansky-pudlak syndrome.

PubMed

Gradstein, Libe; FitzGibbon, Edmond J; Tsilou, Ekaterini T; Rubin, Benjamin I; Huizing, Marjan; Gahl, William A

2005-08-01

Hermansky-Pudlak Syndrome (HPS) is a type of oculocutaneous albinism associated with a bleeding diathesis and pulmonary fibrosis. Although it is known that patients with HPS exhibit nystagmus, the nature of these abnormal eye movements has not been studied. Twenty-seven patients with HPS, diagnosed by platelet morphology and genetic analysis, underwent a systemic evaluation and complete eye examination. Twenty-five had eye movement recordings using magnetic search coil, infrared, or video oculography. All patients had iris transillumination, foveal hypoplasia, and variable hypopigmentation in skin and eyes. All had bleeding tendencies, and 2 reported excessive bleeding during strabismus surgery. Nine patients had pulmonary fibrosis. Visual acuities ranged from 20/20- to 20/320. Twenty patients had strabismus despite 6 having strabismus surgery previously. Ocular oscillations consistent with congenital nystagmus (CN) were clinically evident in 24 of 27 patients, and half showed periodic alternating nystagmus. In 3 patients without CN, eye movement recordings revealed minimal end-gaze nystagmus, square-wave jerks, drift during fixation and saccades, and low-gain pursuit. These patients had melanin in the posterior pole and better visual acuities than the others (P = 0.002). Most patients with HPS have CN, and many have periodic alternating nystagmus. Some have subtle eye movement abnormalities without clinically evident nystagmus, which can obscure the diagnosis, especially if hypopigmentation is mild. Absence of clinical nystagmus in a child with HPS suggests good vision. Patients with albinism, especially before surgery, should be evaluated for HPS to prevent life-threatening complications.

Hawk Eyes I: Diurnal Raptors Differ in Visual Fields and Degree of Eye Movement

PubMed Central

O'Rourke, Colleen T.; Hall, Margaret I.; Pitlik, Todd; Fernández-Juricic, Esteban

2010-01-01

Background Different strategies to search and detect prey may place specific demands on sensory modalities. We studied visual field configuration, degree of eye movement, and orbit orientation in three diurnal raptors belonging to the Accipitridae and Falconidae families. Methodology/Principal Findings We used an ophthalmoscopic reflex technique and an integrated 3D digitizer system. We found inter-specific variation in visual field configuration and degree of eye movement, but not in orbit orientation. Red-tailed Hawks have relatively small binocular areas (∼33°) and wide blind areas (∼82°), but intermediate degree of eye movement (∼5°), which underscores the importance of lateral vision rather than binocular vision to scan for distant prey in open areas. Cooper's Hawks' have relatively wide binocular fields (∼36°), small blind areas (∼60°), and high degree of eye movement (∼8°), which may increase visual coverage and enhance prey detection in closed habitats. Additionally, we found that Cooper's Hawks can visually inspect the items held in the tip of the bill, which may facilitate food handling. American Kestrels have intermediate-sized binocular and lateral areas that may be used in prey detection at different distances through stereopsis and motion parallax; whereas the low degree eye movement (∼1°) may help stabilize the image when hovering above prey before an attack. Conclusions We conclude that: (a) there are between-species differences in visual field configuration in these diurnal raptors; (b) these differences are consistent with prey searching strategies and degree of visual obstruction in the environment (e.g., open and closed habitats); (c) variations in the degree of eye movement between species appear associated with foraging strategies; and (d) the size of the binocular and blind areas in hawks can vary substantially due to eye movements. Inter-specific variation in visual fields and eye movements can influence behavioral

Hawk eyes I: diurnal raptors differ in visual fields and degree of eye movement.

PubMed

O'Rourke, Colleen T; Hall, Margaret I; Pitlik, Todd; Fernández-Juricic, Esteban

2010-09-22

Different strategies to search and detect prey may place specific demands on sensory modalities. We studied visual field configuration, degree of eye movement, and orbit orientation in three diurnal raptors belonging to the Accipitridae and Falconidae families. We used an ophthalmoscopic reflex technique and an integrated 3D digitizer system. We found inter-specific variation in visual field configuration and degree of eye movement, but not in orbit orientation. Red-tailed Hawks have relatively small binocular areas (∼33°) and wide blind areas (∼82°), but intermediate degree of eye movement (∼5°), which underscores the importance of lateral vision rather than binocular vision to scan for distant prey in open areas. Cooper's Hawks' have relatively wide binocular fields (∼36°), small blind areas (∼60°), and high degree of eye movement (∼8°), which may increase visual coverage and enhance prey detection in closed habitats. Additionally, we found that Cooper's Hawks can visually inspect the items held in the tip of the bill, which may facilitate food handling. American Kestrels have intermediate-sized binocular and lateral areas that may be used in prey detection at different distances through stereopsis and motion parallax; whereas the low degree eye movement (∼1°) may help stabilize the image when hovering above prey before an attack. We conclude that: (a) there are between-species differences in visual field configuration in these diurnal raptors; (b) these differences are consistent with prey searching strategies and degree of visual obstruction in the environment (e.g., open and closed habitats); (c) variations in the degree of eye movement between species appear associated with foraging strategies; and (d) the size of the binocular and blind areas in hawks can vary substantially due to eye movements. Inter-specific variation in visual fields and eye movements can influence behavioral strategies to visually search for and track prey while

An information maximization model of eye movements

NASA Technical Reports Server (NTRS)

Renninger, Laura Walker; Coughlan, James; Verghese, Preeti; Malik, Jitendra

2005-01-01

We propose a sequential information maximization model as a general strategy for programming eye movements. The model reconstructs high-resolution visual information from a sequence of fixations, taking into account the fall-off in resolution from the fovea to the periphery. From this framework we get a simple rule for predicting fixation sequences: after each fixation, fixate next at the location that minimizes uncertainty (maximizes information) about the stimulus. By comparing our model performance to human eye movement data and to predictions from a saliency and random model, we demonstrate that our model is best at predicting fixation locations. Modeling additional biological constraints will improve the prediction of fixation sequences. Our results suggest that information maximization is a useful principle for programming eye movements.

Eye movements reflect and shape strategies in fraction comparison

PubMed Central

Ischebeck, Anja; Weilharter, Marina; Körner, Christof

2016-01-01

The comparison of fractions is a difficult task that can often be facilitated by separately comparing components (numerators and denominators) of the fractions—that is, by applying so-called component-based strategies. The usefulness of such strategies depends on the type of fraction pair to be compared. We investigated the temporal organization and the flexibility of strategy deployment in fraction comparison by evaluating sequences of eye movements in 20 young adults. We found that component-based strategies could account for the response times and the overall number of fixations observed for the different fraction pairs. The analysis of eye movement sequences showed that the initial eye movements in a trial were characterized by stereotypical scanning patterns indicative of an exploratory phase that served to establish the kind of fraction pair presented. Eye movements that followed this phase adapted to the particular type of fraction pair and indicated the deployment of specific comparison strategies. These results demonstrate that participants employ eye movements systematically to support strategy use in fraction comparison. Participants showed a remarkable flexibility to adapt to the most efficient strategy on a trial-by-trial basis. Our results confirm the value of eye movement measurements in the exploration of strategic adaptation in complex tasks. PMID:26039819

Eye movements reflect and shape strategies in fraction comparison.

PubMed

Ischebeck, Anja; Weilharter, Marina; Körner, Christof

2016-01-01

The comparison of fractions is a difficult task that can often be facilitated by separately comparing components (numerators and denominators) of the fractions--that is, by applying so-called component-based strategies. The usefulness of such strategies depends on the type of fraction pair to be compared. We investigated the temporal organization and the flexibility of strategy deployment in fraction comparison by evaluating sequences of eye movements in 20 young adults. We found that component-based strategies could account for the response times and the overall number of fixations observed for the different fraction pairs. The analysis of eye movement sequences showed that the initial eye movements in a trial were characterized by stereotypical scanning patterns indicative of an exploratory phase that served to establish the kind of fraction pair presented. Eye movements that followed this phase adapted to the particular type of fraction pair and indicated the deployment of specific comparison strategies. These results demonstrate that participants employ eye movements systematically to support strategy use in fraction comparison. Participants showed a remarkable flexibility to adapt to the most efficient strategy on a trial-by-trial basis. Our results confirm the value of eye movement measurements in the exploration of strategic adaptation in complex tasks.

Anticipatory Smooth Eye Movements in Autism Spectrum Disorder

PubMed Central

Aitkin, Cordelia D.; Santos, Elio M.; Kowler, Eileen

2013-01-01

Smooth pursuit eye movements are important for vision because they maintain the line of sight on targets that move smoothly within the visual field. Smooth pursuit is driven by neural representations of motion, including a surprisingly strong influence of high-level signals representing expected motion. We studied anticipatory smooth eye movements (defined as smooth eye movements in the direction of expected future motion) produced by salient visual cues in a group of high-functioning observers with Autism Spectrum Disorder (ASD), a condition that has been associated with difficulties in either generating predictions, or translating predictions into effective motor commands. Eye movements were recorded while participants pursued the motion of a disc that moved within an outline drawing of an inverted Y-shaped tube. The cue to the motion path was a visual barrier that blocked the untraveled branch (right or left) of the tube. ASD participants showed strong anticipatory smooth eye movements whose velocity was the same as that of a group of neurotypical participants. Anticipatory smooth eye movements appeared on the very first cued trial, indicating that trial-by-trial learning was not responsible for the responses. These results are significant because they show that anticipatory capacities are intact in high-functioning ASD in cases where the cue to the motion path is highly salient and unambiguous. Once the ability to generate anticipatory pursuit is demonstrated, the study of the anticipatory responses with a variety of types of cues provides a window into the perceptual or cognitive processes that underlie the interpretation of events in natural environments or social situations. PMID:24376667

Anticipatory smooth eye movements in autism spectrum disorder.

PubMed

Aitkin, Cordelia D; Santos, Elio M; Kowler, Eileen

2013-01-01

Smooth pursuit eye movements are important for vision because they maintain the line of sight on targets that move smoothly within the visual field. Smooth pursuit is driven by neural representations of motion, including a surprisingly strong influence of high-level signals representing expected motion. We studied anticipatory smooth eye movements (defined as smooth eye movements in the direction of expected future motion) produced by salient visual cues in a group of high-functioning observers with Autism Spectrum Disorder (ASD), a condition that has been associated with difficulties in either generating predictions, or translating predictions into effective motor commands. Eye movements were recorded while participants pursued the motion of a disc that moved within an outline drawing of an inverted Y-shaped tube. The cue to the motion path was a visual barrier that blocked the untraveled branch (right or left) of the tube. ASD participants showed strong anticipatory smooth eye movements whose velocity was the same as that of a group of neurotypical participants. Anticipatory smooth eye movements appeared on the very first cued trial, indicating that trial-by-trial learning was not responsible for the responses. These results are significant because they show that anticipatory capacities are intact in high-functioning ASD in cases where the cue to the motion path is highly salient and unambiguous. Once the ability to generate anticipatory pursuit is demonstrated, the study of the anticipatory responses with a variety of types of cues provides a window into the perceptual or cognitive processes that underlie the interpretation of events in natural environments or social situations.

The rostromedial tegmental nucleus is essential for non-rapid eye movement sleep.

PubMed

Yang, Su-Rong; Hu, Zhen-Zhen; Luo, Yan-Jia; Zhao, Ya-Nan; Sun, Huan-Xin; Yin, Dou; Wang, Chen-Yao; Yan, Yu-Dong; Wang, Dian-Ru; Yuan, Xiang-Shan; Ye, Chen-Bo; Guo, Wei; Qu, Wei-Min; Cherasse, Yoan; Lazarus, Michael; Ding, Yu-Qiang; Huang, Zhi-Li

2018-04-01

The rostromedial tegmental nucleus (RMTg), also called the GABAergic tail of the ventral tegmental area, projects to the midbrain dopaminergic system, dorsal raphe nucleus, locus coeruleus, and other regions. Whether the RMTg is involved in sleep-wake regulation is unknown. In the present study, pharmacogenetic activation of rat RMTg neurons promoted non-rapid eye movement (NREM) sleep with increased slow-wave activity (SWA). Conversely, rats after neurotoxic lesions of 8 or 16 days showed decreased NREM sleep with reduced SWA at lights on. The reduced SWA persisted at least 25 days after lesions. Similarly, pharmacological and pharmacogenetic inactivation of rat RMTg neurons decreased NREM sleep. Electrophysiological experiments combined with optogenetics showed a direct inhibitory connection between the terminals of RMTg neurons and midbrain dopaminergic neurons. The bidirectional effects of the RMTg on the sleep-wake cycle were mimicked by the modulation of ventral tegmental area (VTA)/substantia nigra compacta (SNc) dopaminergic neuronal activity using a pharmacogenetic approach. Furthermore, during the 2-hour recovery period following 6-hour sleep deprivation, the amount of NREM sleep in both the lesion and control rats was significantly increased compared with baseline levels; however, only the control rats showed a significant increase in SWA compared with baseline levels. Collectively, our findings reveal an essential role of the RMTg in the promotion of NREM sleep and homeostatic regulation.

The rostromedial tegmental nucleus is essential for non-rapid eye movement sleep

PubMed Central

Hu, Zhen-Zhen; Luo, Yan-Jia; Zhao, Ya-Nan; Sun, Huan-Xin; Yin, Dou; Wang, Chen-Yao; Yan, Yu-Dong; Wang, Dian-Ru; Yuan, Xiang-Shan; Ye, Chen-Bo; Guo, Wei; Qu, Wei-Min; Cherasse, Yoan; Lazarus, Michael; Ding, Yu-Qiang; Huang, Zhi-Li

2018-01-01

The rostromedial tegmental nucleus (RMTg), also called the GABAergic tail of the ventral tegmental area, projects to the midbrain dopaminergic system, dorsal raphe nucleus, locus coeruleus, and other regions. Whether the RMTg is involved in sleep–wake regulation is unknown. In the present study, pharmacogenetic activation of rat RMTg neurons promoted non-rapid eye movement (NREM) sleep with increased slow-wave activity (SWA). Conversely, rats after neurotoxic lesions of 8 or 16 days showed decreased NREM sleep with reduced SWA at lights on. The reduced SWA persisted at least 25 days after lesions. Similarly, pharmacological and pharmacogenetic inactivation of rat RMTg neurons decreased NREM sleep. Electrophysiological experiments combined with optogenetics showed a direct inhibitory connection between the terminals of RMTg neurons and midbrain dopaminergic neurons. The bidirectional effects of the RMTg on the sleep–wake cycle were mimicked by the modulation of ventral tegmental area (VTA)/substantia nigra compacta (SNc) dopaminergic neuronal activity using a pharmacogenetic approach. Furthermore, during the 2-hour recovery period following 6-hour sleep deprivation, the amount of NREM sleep in both the lesion and control rats was significantly increased compared with baseline levels; however, only the control rats showed a significant increase in SWA compared with baseline levels. Collectively, our findings reveal an essential role of the RMTg in the promotion of NREM sleep and homeostatic regulation. PMID:29652889

iTemplate: A template-based eye movement data analysis approach.

PubMed

Xiao, Naiqi G; Lee, Kang

2018-02-08

Current eye movement data analysis methods rely on defining areas of interest (AOIs). Due to the fact that AOIs are created and modified manually, variances in their size, shape, and location are unavoidable. These variances affect not only the consistency of the AOI definitions, but also the validity of the eye movement analyses based on the AOIs. To reduce the variances in AOI creation and modification and achieve a procedure to process eye movement data with high precision and efficiency, we propose a template-based eye movement data analysis method. Using a linear transformation algorithm, this method registers the eye movement data from each individual stimulus to a template. Thus, users only need to create one set of AOIs for the template in order to analyze eye movement data, rather than creating a unique set of AOIs for all individual stimuli. This change greatly reduces the error caused by the variance from manually created AOIs and boosts the efficiency of the data analysis. Furthermore, this method can help researchers prepare eye movement data for some advanced analysis approaches, such as iMap. We have developed software (iTemplate) with a graphic user interface to make this analysis method available to researchers.

The King-Devick (K-D) test of rapid eye movements: a bedside correlate of disability and quality of life in MS.

PubMed

Moster, Stephen; Wilson, James A; Galetta, Steven L; Balcer, Laura J

2014-08-15

We investigated the King-Devick (K-D) test of rapid number naming as a visual performance measure in a cohort of patients with multiple sclerosis (MS). In this cross-sectional study, 81 patients with MS and 20 disease-free controls from an ongoing study of visual outcomes underwent K-D testing. A test of rapid number naming, K-D requires saccadic eye movements as well as intact vision, attention and concentration. To perform the K-D test, participants are asked to read numbers aloud as quickly as possible from three test cards; the sum of the three test card times in seconds constitutes the summary score. High-contrast visual acuity (VA), low-contrast letter acuity (1.25% and 2.5% levels), retinal nerve fiber layer (RNFL) thickness by optical coherence tomography (OCT), MS Functional Composite (MSFC) and vision-specific quality of life (QOL) measures (25-Item NEI Visual Functioning Questionnaire [NEI-VFQ-25] and 10-Item Neuro-Ophthalmic Supplement) were also assessed. K-D time scores in the MS cohort (total time to read the three test cards) were significantly higher (worse) compared to those for disease-free controls (P=0.003, linear regression, accounting for age). Within the MS cohort, higher K-D scores were associated with worse scores for the NEI-VFQ-25 composite (P<0.001), 10-Item Neuro-Ophthalmic Supplement (P<0.001), binocular low-contrast acuity (2.5%, 1.25%, P<0.001, and high-contrast VA (P=0.003). Monocular low-contrast vision scores (P=0.001-0.009) and RNFL thickness (P=0.001) were also reduced in eyes of patients with worse K-D scores (GEE models accounting for age and within-patient, inter-eye correlations). Patients with a history of optic neuritis (ON) had increased (worse) K-D scores. Patients who classified their work disability status as disabled (receiving disability pension) did worse on K-D testing compared to those working full-time (P=0.001, accounting for age). The K-D test, a <2 minute bedside test of rapid number naming, is associated

Eye movements and attention in reading, scene perception, and visual search.

PubMed

Rayner, Keith

2009-08-01

Eye movements are now widely used to investigate cognitive processes during reading, scene perception, and visual search. In this article, research on the following topics is reviewed with respect to reading: (a) the perceptual span (or span of effective vision), (b) preview benefit, (c) eye movement control, and (d) models of eye movements. Related issues with respect to eye movements during scene perception and visual search are also reviewed. It is argued that research on eye movements during reading has been somewhat advanced over research on eye movements in scene perception and visual search and that some of the paradigms developed to study reading should be more widely adopted in the study of scene perception and visual search. Research dealing with "real-world" tasks and research utilizing the visual-world paradigm are also briefly discussed.

Acting without seeing: eye movements reveal visual processing without awareness.

PubMed

Spering, Miriam; Carrasco, Marisa

2015-04-01

Visual perception and eye movements are considered to be tightly linked. Diverse fields, ranging from developmental psychology to computer science, utilize eye tracking to measure visual perception. However, this prevailing view has been challenged by recent behavioral studies. Here, we review converging evidence revealing dissociations between the contents of perceptual awareness and different types of eye movement. Such dissociations reveal situations in which eye movements are sensitive to particular visual features that fail to modulate perceptual reports. We also discuss neurophysiological, neuroimaging, and clinical studies supporting the role of subcortical pathways for visual processing without awareness. Our review links awareness to perceptual-eye movement dissociations and furthers our understanding of the brain pathways underlying vision and movement with and without awareness. Copyright © 2015 Elsevier Ltd. All rights reserved.

A review on eye movement studies in childhood and adolescent psychiatry.

PubMed

Rommelse, Nanda N J; Van der Stigchel, Stefan; Sergeant, Joseph A

2008-12-01

The neural substrates of eye movement measures are largely known. Therefore, measurement of eye movements in psychiatric disorders may provide insight into the underlying neuropathology of these disorders. Visually guided saccades, antisaccades, memory guided saccades, and smooth pursuit eye movements will be reviewed in various childhood psychiatric disorders. The four aims of this review are (1) to give a thorough overview of eye movement studies in a wide array of psychiatric disorders occurring during childhood and adolescence (attention-deficit/hyperactivity disorder, oppositional deviant disorder and conduct disorder, autism spectrum disorders, reading disorder, childhood-onset schizophrenia, Tourette's syndrome, obsessive compulsive disorder, and anxiety and depression), (2) to discuss the specificity and overlap of eye movement findings across disorders and paradigms, (3) to discuss the developmental aspects of eye movement abnormalities in childhood and adolescence psychiatric disorders, and (4) to present suggestions for future research. In order to make this review of interest to a broad audience, attention will be given to the clinical manifestation of the disorders and the theoretical background of the eye movement paradigms.

Just a scary dream? A brief review of sleep terrors, nightmares, and rapid eye movement sleep behavior disorder.

PubMed

Haupt, Mark; Sheldon, Stephen H; Loghmanee, Darius

2013-10-01

The clinical spectrum of sleep disorders in children is broad, ranging from primary snoring and obstructive sleep apnea (OSA) syndrome to complex sleep-related behaviors and movement disorders. Although snoring and OSA typically receive significant attention and discussion, other biologically based sleep disorders are as common, if not more common, in children. A general pediatrician is frequently presented with the complaint of sleep talking, sleep walking, or abnormal movements during sleep. Even more alarming is the presentation of the child suddenly and explosively screaming during sleep. Such complaints fall under the category of parasomnias. Exclusive to sleep and wake-to-sleep transitions, these parasomnias include arousals with abnormal motor, behavioral, autonomic, or sensory symptoms. Parasomnias can be noticeably dissimilar in clinical manifestations, but most share biologic characteristics. Three parasomnias associated with loud vocalizations associated with sleep that can present to general practitioners include sleep terrors, nightmares, and rapid eye movement sleep behavior disorder (RBD). Although usually benign, these sleep disorders can be disruptive and even potentially dangerous to the patient and can often be threatening to quality of life. In this article, we describe the clinical features of some of these disorders and how to differentiate between their alarming presentations. Copyright 2013, SLACK Incorporated.

Difference in Visual Processing Assessed by Eye Vergence Movements

PubMed Central

Solé Puig, Maria; Puigcerver, Laura; Aznar-Casanova, J. Antonio; Supèr, Hans

2013-01-01

Orienting visual attention is closely linked to the oculomotor system. For example, a shift of attention is usually followed by a saccadic eye movement and can be revealed by micro saccades. Recently we reported a novel role of another type of eye movement, namely eye vergence, in orienting visual attention. Shifts in visuospatial attention are characterized by the response modulation to a selected target. However, unlike (micro-) saccades, eye vergence movements do not carry spatial information (except for depth) and are thus not specific to a particular visual location. To further understand the role of eye vergence in visual attention, we tested subjects with different perceptual styles. Perceptual style refers to the characteristic way individuals perceive environmental stimuli, and is characterized by a spatial difference (local vs. global) in perceptual processing. We tested field independent (local; FI) and field dependent (global; FD) observers in a cue/no-cue task and a matching task. We found that FI observers responded faster and had stronger modulation in eye vergence in both tasks than FD subjects. The results may suggest that eye vergence modulation may relate to the trade-off between the size of spatial region covered by attention and the processing efficiency of sensory information. Alternatively, vergence modulation may have a role in the switch in cortical state to prepare the visual system for new incoming sensory information. In conclusion, vergence eye movements may be added to the growing list of functions of fixational eye movements in visual perception. However, further studies are needed to elucidate its role. PMID:24069140

Eye Movement Indices in the Study of Depressive Disorder

PubMed Central

LI, Yu; XU, Yangyang; XIA, Mengqing; ZHANG, Tianhong; WANG, Junjie; LIU, Xu; HE, Yongguang; WANG, Jijun

2016-01-01

Background Impaired cognition is one of the most common core symptoms of depressive disorder. Eye movement testing mainly reflects patients’ cognitive functions, such as cognition, memory, attention, recognition, and recall. This type of testing has great potential to improve theories related to cognitive functioning in depressive episodes as well as potential in its clinical application. Aims This study investigated whether eye movement indices of patients with unmedicated depressive disorder were abnormal or not, as well as the relationship between these indices and mental symptoms. Methods Sixty patients with depressive disorder and sixty healthy controls (who were matched by gender, age and years of education) were recruited, and completed eye movement tests including three tasks: fixation task, saccade task and free-view task. The EyeLink desktop eye tracking system was employed to collect eye movement information, and analyze the eye movement indices of the three tasks between the two groups. Results (1) In the fixation task, compared to healthy controls, patients with depressive disorder showed more fixations, shorter fixation durations, more saccades and longer saccadic lengths; (2) In the saccade task, patients with depressive disorder showed longer anti-saccade latencies and smaller anti-saccade peak velocities; (3) In the free-view task, patients with depressive disorder showed fewer saccades and longer mean fixation durations; (4) Correlation analysis showed that there was a negative correlation between the pro-saccade amplitude and anxiety symptoms, and a positive correlation between the anti-saccade latency and anxiety symptoms. The depression symptoms were negatively correlated with fixation times, saccades, and saccadic paths respectively in the free-view task; while the mean fixation duration and depression symptoms showed a positive correlation. Conclusion Compared to healthy controls, patients with depressive disorder showed significantly

Evaluation of the King-Devick Test to Assess Eye Movements and the Performance of Rapid Number Naming in Concussed and Non-Concussed Service Members

DTIC Science & Technology

2017-07-01

pre -Combatives baseline and their post - Combatives assessment, to determine to what extent individuals diagnosed as having an mTBI event differ from...their King- Devick Test pre -Combatives baseline, and to determine to what extent individuals who report a history of concussion during their pre ...Award Number: W81XWH-14-1-0173 TITLE: Evaluation of the King-Devick Test to Assess Eye Movements and the Performance of Rapid Number Naming in

Eye movements during spoken word recognition in Russian children.

PubMed

Sekerina, Irina A; Brooks, Patricia J

2007-09-01

This study explores incremental processing in spoken word recognition in Russian 5- and 6-year-olds and adults using free-viewing eye-tracking. Participants viewed scenes containing pictures of four familiar objects and clicked on a target embedded in a spoken instruction. In the cohort condition, two object names shared identical three-phoneme onsets. In the noncohort condition, all object names had unique onsets. Coarse-grain analyses of eye movements indicated that adults produced looks to the competitor on significantly more cohort trials than on noncohort trials, whereas children surprisingly failed to demonstrate cohort competition due to widespread exploratory eye movements across conditions. Fine-grain analyses, in contrast, showed a similar time course of eye movements across children and adults, but with cohort competition lingering more than 1s longer in children. The dissociation between coarse-grain and fine-grain eye movements indicates a need to consider multiple behavioral measures in making developmental comparisons in language processing.

A prominent role for amygdaloid complexes in the Variability in Heart Rate (VHR) during Rapid Eye Movement (REM) sleep relative to wakefulness.

PubMed

Desseilles, Martin; Vu, Thanh Dang; Laureys, Steven; Peigneux, Philippe; Degueldre, Christian; Phillips, Christophe; Maquet, Pierre

2006-09-01

Rapid eye movement sleep (REMS) is associated with intense neuronal activity, rapid eye movements, muscular atonia and dreaming. Another important feature in REMS is the instability in autonomic, especially in cardiovascular regulation. The neural mechanisms underpinning the variability in heart rate (VHR) during REMS are not known in detail, especially in humans. During wakefulness, the right insula has frequently been reported as involved in cardiovascular regulation but this might not be the case during REMS. We aimed at characterizing the neural correlates of VHR during REMS as compared to wakefulness and to slow wave sleep (SWS), the other main component of human sleep, in normal young adults, based on the statistical analysis of a set of H(2)(15)O positron emission tomography (PET) sleep data acquired during SWS, REMS and wakefulness. The results showed that VHR correlated more tightly during REMS than during wakefulness with the rCBF in the right amygdaloid complex. Moreover, we assessed whether functional relationships between amygdala and any brain area changed depending the state of vigilance. Only the activity within in the insula was found to covary with the amygdala, significantly more tightly during wakefulness than during REMS in relation to the VHR. The functional connectivity between the amygdala and the insular cortex, two brain areas involved in cardiovascular regulation, differs significantly in REMS as compared to wakefulness. This suggests a functional reorganization of central cardiovascular regulation during REMS.

Quantitative assessment of motor speech abnormalities in idiopathic rapid eye movement sleep behaviour disorder.

PubMed

Rusz, Jan; Hlavnička, Jan; Tykalová, Tereza; Bušková, Jitka; Ulmanová, Olga; Růžička, Evžen; Šonka, Karel

2016-03-01

Patients with idiopathic rapid eye movement sleep behaviour disorder (RBD) are at substantial risk for developing Parkinson's disease (PD) or related neurodegenerative disorders. Speech is an important indicator of motor function and movement coordination, and therefore may be an extremely sensitive early marker of changes due to prodromal neurodegeneration. Speech data were acquired from 16 RBD subjects and 16 age- and sex-matched healthy control subjects. Objective acoustic assessment of 15 speech dimensions representing various phonatory, articulatory, and prosodic deviations was performed. Statistical models were applied to characterise speech disorders in RBD and to estimate sensitivity and specificity in differentiating between RBD and control subjects. Some form of speech impairment was revealed in 88% of RBD subjects. Articulatory deficits were the most prominent findings in RBD. In comparison to controls, the RBD group showed significant alterations in irregular alternating motion rates (p = 0.009) and articulatory decay (p = 0.01). The combination of four distinctive speech dimensions, including aperiodicity, irregular alternating motion rates, articulatory decay, and dysfluency, led to 96% sensitivity and 79% specificity in discriminating between RBD and control subjects. Speech impairment was significantly more pronounced in RBD subjects with the motor score of the Unified Parkinson's Disease Rating Scale greater than 4 points when compared to other RBD individuals. Simple quantitative speech motor measures may be suitable for the reliable detection of prodromal neurodegeneration in subjects with RBD, and therefore may provide important outcomes for future therapy trials. Copyright © 2015 Elsevier B.V. All rights reserved.

Idiosyncratic characteristics of saccadic eye movements when viewing different visual environments.

PubMed

Andrews, T J; Coppola, D M

1999-08-01

Eye position was recorded in different viewing conditions to assess whether the temporal and spatial characteristics of saccadic eye movements in different individuals are idiosyncratic. Our aim was to determine the degree to which oculomotor control is based on endogenous factors. A total of 15 naive subjects viewed five visual environments: (1) The absence of visual stimulation (i.e. a dark room); (2) a repetitive visual environment (i.e. simple textured patterns); (3) a complex natural scene; (4) a visual search task; and (5) reading text. Although differences in visual environment had significant effects on eye movements, idiosyncrasies were also apparent. For example, the mean fixation duration and size of an individual's saccadic eye movements when passively viewing a complex natural scene covaried significantly with those same parameters in the absence of visual stimulation and in a repetitive visual environment. In contrast, an individual's spatio-temporal characteristics of eye movements during active tasks such as reading text or visual search covaried together, but did not correlate with the pattern of eye movements detected when viewing a natural scene, simple patterns or in the dark. These idiosyncratic patterns of eye movements in normal viewing reveal an endogenous influence on oculomotor control. The independent covariance of eye movements during different visual tasks shows that saccadic eye movements during active tasks like reading or visual search differ from those engaged during the passive inspection of visual scenes.

Learning rational temporal eye movement strategies.

PubMed

Hoppe, David; Rothkopf, Constantin A

2016-07-19

During active behavior humans redirect their gaze several times every second within the visual environment. Where we look within static images is highly efficient, as quantified by computational models of human gaze shifts in visual search and face recognition tasks. However, when we shift gaze is mostly unknown despite its fundamental importance for survival in a dynamic world. It has been suggested that during naturalistic visuomotor behavior gaze deployment is coordinated with task-relevant events, often predictive of future events, and studies in sportsmen suggest that timing of eye movements is learned. Here we establish that humans efficiently learn to adjust the timing of eye movements in response to environmental regularities when monitoring locations in the visual scene to detect probabilistically occurring events. To detect the events humans adopt strategies that can be understood through a computational model that includes perceptual and acting uncertainties, a minimal processing time, and, crucially, the intrinsic costs of gaze behavior. Thus, subjects traded off event detection rate with behavioral costs of carrying out eye movements. Remarkably, based on this rational bounded actor model the time course of learning the gaze strategies is fully explained by an optimal Bayesian learner with humans' characteristic uncertainty in time estimation, the well-known scalar law of biological timing. Taken together, these findings establish that the human visual system is highly efficient in learning temporal regularities in the environment and that it can use these regularities to control the timing of eye movements to detect behaviorally relevant events.

A Review on Eye Movement Studies in Childhood and Adolescent Psychiatry

ERIC Educational Resources Information Center

Rommelse, Nanda N. J.; Van der Stigchel, Stefan; Sergeant, Joseph A.

2008-01-01

The neural substrates of eye movement measures are largely known. Therefore, measurement of eye movements in psychiatric disorders may provide insight into the underlying neuropathology of these disorders. Visually guided saccades, antisaccades, memory guided saccades, and smooth pursuit eye movements will be reviewed in various childhood…

Visual field recovery after vision restoration therapy (VRT) is independent of eye movements: an eye tracker study.

PubMed

Kasten, Erich; Bunzenthal, Ulrike; Sabel, Bernhard A

2006-11-25

It has been argued that patients with visual field defects compensate for their deficit by making more frequent eye movements toward the hemianopic field and that visual field enlargements found after vision restoration therapy (VRT) may be an artefact of such eye movements. In order to determine if this was correct, we recorded eye movements in hemianopic subjects before and after VRT. Visual fields were measured in subjects with homonymous visual field defects (n=15) caused by trauma, cerebral ischemia or haemorrhage (lesion age >6 months). Visual field charts were plotted using both high-resolution perimetry (HRP) and conventional perimetry before and after a 3-month period of VRT, with eye movements being recorded with a 2D-eye tracker. This permitted quantification of eye positions and measurements of deviation from fixation. VRT lead to significant visual field enlargements as indicated by an increase of stimulus detection of 3.8% when tested using HRP and about 2.2% (OD) and 3.5% (OS) fewer misses with conventional perimetry. Eye movements were expressed as the standard deviations (S.D.) of the eye position recordings from fixation. Before VRT, the S.D. was +/-0.82 degrees horizontally and +/-1.16 degrees vertically; after VRT, it was +/-0.68 degrees and +/-1.39 degrees , respectively. A cluster analysis of the horizontal eye movements before VRT showed three types of subjects with (i) small (n=7), (ii) medium (n=7) or (iii) large fixation instability (n=1). Saccades were directed equally to the right or the left side; i.e., with no preference toward the blind hemifield. After VRT, many subjects showed a smaller variability of horizontal eye movements. Before VRT, 81.6% of the recorded eye positions were found within a range of 1 degrees horizontally from fixation, whereas after VRT, 88.3% were within that range. In the 2 degrees range, we found 94.8% before and 98.9% after VRT. Subjects moved their eyes 5 degrees or more 0.3% of the time before VRT versus 0

Contextual effects on smooth-pursuit eye movements.

PubMed

Spering, Miriam; Gegenfurtner, Karl R

2007-02-01

Segregating a moving object from its visual context is particularly relevant for the control of smooth-pursuit eye movements. We examined the interaction between a moving object and a stationary or moving visual context to determine the role of the context motion signal in driving pursuit. Eye movements were recorded from human observers to a medium-contrast Gaussian dot that moved horizontally at constant velocity. A peripheral context consisted of two vertically oriented sinusoidal gratings, one above and one below the stimulus trajectory, that were either stationary or drifted into the same or opposite direction as that of the target at different velocities. We found that a stationary context impaired pursuit acceleration and velocity and prolonged pursuit latency. A drifting context enhanced pursuit performance, irrespective of its motion direction. This effect was modulated by context contrast and orientation. When a context was briefly perturbed to move faster or slower eye velocity changed accordingly, but only when the context was drifting along with the target. Perturbing a context into the direction orthogonal to target motion evoked a deviation of the eye opposite to the perturbation direction. We therefore provide evidence for the use of absolute and relative motion cues, or motion assimilation and motion contrast, for the control of smooth-pursuit eye movements.

Eye movement accuracy determines natural interception strategies.

PubMed

Fooken, Jolande; Yeo, Sang-Hoon; Pai, Dinesh K; Spering, Miriam

2016-11-01

Eye movements aid visual perception and guide actions such as reaching or grasping. Most previous work on eye-hand coordination has focused on saccadic eye movements. Here we show that smooth pursuit eye movement accuracy strongly predicts both interception accuracy and the strategy used to intercept a moving object. We developed a naturalistic task in which participants (n = 42 varsity baseball players) intercepted a moving dot (a "2D fly ball") with their index finger in a designated "hit zone." Participants were instructed to track the ball with their eyes, but were only shown its initial launch (100-300 ms). Better smooth pursuit resulted in more accurate interceptions and determined the strategy used for interception, i.e., whether interception was early or late in the hit zone. Even though early and late interceptors showed equally accurate interceptions, they may have relied on distinct tactics: early interceptors used cognitive heuristics, whereas late interceptors' performance was best predicted by pursuit accuracy. Late interception may be beneficial in real-world tasks as it provides more time for decision and adjustment. Supporting this view, baseball players who were more senior were more likely to be late interceptors. Our findings suggest that interception strategies are optimally adapted to the proficiency of the pursuit system.

Sleep alterations in mammals: did aquatic conditions inhibit rapid eye movement sleep?

PubMed

Madan, Vibha; Jha, Sushil K

2012-12-01

Sleep has been studied widely in mammals and to some extent in other vertebrates. Higher vertebrates such as birds and mammals have evolved an inimitable rapid eye movement (REM) sleep state. During REM sleep, postural muscles become atonic and the temperature regulating machinery remains suspended. Although REM sleep is present in almost all the terrestrial mammals, the aquatic mammals have either radically reduced or completely eliminated REM sleep. Further, we found a significant negative correlation between REM sleep and the adaptation of the organism to live on land or in water. The amount of REM sleep is highest in terrestrial mammals, significantly reduced in semi-aquatic mammals and completely absent or negligible in aquatic mammals. The aquatic mammals are obligate swimmers and have to surface at regular intervals for air. Also, these animals live in thermally challenging environments, where the conductive heat loss is approximately ~90 times greater than air. Therefore, they have to be moving most of the time. As an adaptation, they have evolved unihemispheric sleep, during which they can rove as well as rest. A condition that immobilizes muscle activity and suspends the thermoregulatory machinery, as happens during REM sleep, is not suitable for these animals. It is possible that, in accord with Darwin's theory, aquatic mammals might have abolished REM sleep with time. In this review, we discuss the possibility of the intrinsic role of aquatic conditions in the elimination of REM sleep in the aquatic mammals.

Eye movement analysis for activity recognition using electrooculography.

PubMed

Bulling, Andreas; Ward, Jamie A; Gellersen, Hans; Tröster, Gerhard

2011-04-01

In this work, we investigate eye movement analysis as a new sensing modality for activity recognition. Eye movement data were recorded using an electrooculography (EOG) system. We first describe and evaluate algorithms for detecting three eye movement characteristics from EOG signals-saccades, fixations, and blinks-and propose a method for assessing repetitive patterns of eye movements. We then devise 90 different features based on these characteristics and select a subset of them using minimum redundancy maximum relevance (mRMR) feature selection. We validate the method using an eight participant study in an office environment using an example set of five activity classes: copying a text, reading a printed paper, taking handwritten notes, watching a video, and browsing the Web. We also include periods with no specific activity (the NULL class). Using a support vector machine (SVM) classifier and person-independent (leave-one-person-out) training, we obtain an average precision of 76.1 percent and recall of 70.5 percent over all classes and participants. The work demonstrates the promise of eye-based activity recognition (EAR) and opens up discussion on the wider applicability of EAR to other activities that are difficult, or even impossible, to detect using common sensing modalities.

Gaze failure, drifting eye movements, and centripetal nystagmus in cerebellar disease.

PubMed Central

Leech, J; Gresty, M; Hess, K; Rudge, P

1977-01-01

Three abnormalities of eye movement in man are described which are indicative of cerebellar system disorder, namely, centripetally beating nystagmus, failure to maintain lateral gaze either in darkness or with eye closure, and slow drifting movements of the eyes in the absence of fixation. Similar eye movement signs follow cerebellectomy in the primate and the cat. These abnormalities of eye movement, together with other signs of cerebellar disease, such as rebound alternating, and gaze paretic nystagmus, are explained by the hypothesis that the cerebellum helps to maintain lateral gaze and that brain stem mechanisms which monitor gaze position generate compensatory biases in the absence of normal cerebellar function. PMID:603785

Odors enhance slow-wave activity in non-rapid eye movement sleep

PubMed Central

Perl, Ofer; Arzi, Anat; Sela, Lee; Secundo, Lavi; Holtzman, Yael; Samnon, Perry; Oksenberg, Arie; Sobel, Noam

2016-01-01

Most forms of suprathreshold sensory stimulation perturb sleep. In contrast, presentation of pure olfactory or mild trigeminal odorants does not lead to behavioral or physiological arousal. In fact, some odors promote objective and subjective measures of sleep quality in humans and rodents. The brain mechanisms underlying these sleep-protective properties of olfaction remain unclear. Slow oscillations in the electroencephalogram (EEG) are a marker of deep sleep, and K complexes (KCs) are an EEG marker of cortical response to sensory interference. We therefore hypothesized that odorants presented during sleep will increase power in slow EEG oscillations. Moreover, given that odorants do not drive sleep interruption, we hypothesized that unlike other sensory stimuli odorants would not drive KCs. To test these hypotheses we used polysomnography to measure sleep in 34 healthy subjects (19 women, 15 men; mean age 26.5 ± 2.5 yr) who were repeatedly presented with odor stimuli via a computer-controlled air-dilution olfactometer over the course of a single night. Each participant was exposed to one of four odorants, lavender oil (n = 13), vetiver oil (n = 5), vanillin (n = 12), or ammonium sulfide (n = 4), for durations of 5, 10, and 20 s every 9–15 min. Consistent with our hypotheses, we found that odor presentation during sleep enhanced the power of delta (0.5–4 Hz) and slow spindle (9–12 Hz) frequencies during non-rapid eye movement sleep. The increase was proportionate to odor duration. In addition, odor presentation did not modulate the occurrence of KCs. These findings imply a sleep-promoting olfactory mechanism that may deepen sleep through driving increased slow-frequency oscillations. PMID:26888107

Odors enhance slow-wave activity in non-rapid eye movement sleep.

PubMed

Perl, Ofer; Arzi, Anat; Sela, Lee; Secundo, Lavi; Holtzman, Yael; Samnon, Perry; Oksenberg, Arie; Sobel, Noam; Hairston, Ilana S

2016-05-01

Most forms of suprathreshold sensory stimulation perturb sleep. In contrast, presentation of pure olfactory or mild trigeminal odorants does not lead to behavioral or physiological arousal. In fact, some odors promote objective and subjective measures of sleep quality in humans and rodents. The brain mechanisms underlying these sleep-protective properties of olfaction remain unclear. Slow oscillations in the electroencephalogram (EEG) are a marker of deep sleep, and K complexes (KCs) are an EEG marker of cortical response to sensory interference. We therefore hypothesized that odorants presented during sleep will increase power in slow EEG oscillations. Moreover, given that odorants do not drive sleep interruption, we hypothesized that unlike other sensory stimuli odorants would not drive KCs. To test these hypotheses we used polysomnography to measure sleep in 34 healthy subjects (19 women, 15 men; mean age 26.5 ± 2.5 yr) who were repeatedly presented with odor stimuli via a computer-controlled air-dilution olfactometer over the course of a single night. Each participant was exposed to one of four odorants, lavender oil (n = 13), vetiver oil (n = 5), vanillin (n = 12), or ammonium sulfide (n = 4), for durations of 5, 10, and 20 s every 9-15 min. Consistent with our hypotheses, we found that odor presentation during sleep enhanced the power of delta (0.5-4 Hz) and slow spindle (9-12 Hz) frequencies during non-rapid eye movement sleep. The increase was proportionate to odor duration. In addition, odor presentation did not modulate the occurrence of KCs. These findings imply a sleep-promoting olfactory mechanism that may deepen sleep through driving increased slow-frequency oscillations. Copyright © 2016 the American Physiological Society.

Diagnostic accuracy of eye movements in assessing pedophilia.

PubMed

Fromberger, Peter; Jordan, Kirsten; Steinkrauss, Henrike; von Herder, Jakob; Witzel, Joachim; Stolpmann, Georg; Kröner-Herwig, Birgit; Müller, Jürgen Leo

2012-07-01

Given that recurrent sexual interest in prepubescent children is one of the strongest single predictors for pedosexual offense recidivism, valid and reliable diagnosis of pedophilia is of particular importance. Nevertheless, current assessment methods still fail to fulfill psychometric quality criteria. The aim of the study was to evaluate the diagnostic accuracy of eye-movement parameters in regard to pedophilic sexual preferences. Eye movements were measured while 22 pedophiles (according to ICD-10 F65.4 diagnosis), 8 non-pedophilic forensic controls, and 52 healthy controls simultaneously viewed the picture of a child and the picture of an adult. Fixation latency was assessed as a parameter for automatic attentional processes and relative fixation time to account for controlled attentional processes. Receiver operating characteristic (ROC) analyses, which are based on calculated age-preference indices, were carried out to determine the classifier performance. Cross-validation using the leave-one-out method was used to test the validity of classifiers. Pedophiles showed significantly shorter fixation latencies and significantly longer relative fixation times for child stimuli than either of the control groups. Classifier performance analysis revealed an area under the curve (AUC) = 0.902 for fixation latency and an AUC = 0.828 for relative fixation time. The eye-tracking method based on fixation latency discriminated between pedophiles and non-pedophiles with a sensitivity of 86.4% and a specificity of 90.0%. Cross-validation demonstrated good validity of eye-movement parameters. Despite some methodological limitations, measuring eye movements seems to be a promising approach to assess deviant pedophilic interests. Eye movements, which represent automatic attentional processes, demonstrated high diagnostic accuracy. © 2012 International Society for Sexual Medicine.

Combining EEG and eye tracking: identification, characterization, and correction of eye movement artifacts in electroencephalographic data

PubMed Central

Plöchl, Michael; Ossandón, José P.; König, Peter

2012-01-01

Eye movements introduce large artifacts to electroencephalographic recordings (EEG) and thus render data analysis difficult or even impossible. Trials contaminated by eye movement and blink artifacts have to be discarded, hence in standard EEG-paradigms subjects are required to fixate on the screen. To overcome this restriction, several correction methods including regression and blind source separation have been proposed. Yet, there is no automated standard procedure established. By simultaneously recording eye movements and 64-channel-EEG during a guided eye movement paradigm, we investigate and review the properties of eye movement artifacts, including corneo-retinal dipole changes, saccadic spike potentials and eyelid artifacts, and study their interrelations during different types of eye- and eyelid movements. In concordance with earlier studies our results confirm that these artifacts arise from different independent sources and that depending on electrode site, gaze direction, and choice of reference these sources contribute differently to the measured signal. We assess the respective implications for artifact correction methods and therefore compare the performance of two prominent approaches, namely linear regression and independent component analysis (ICA). We show and discuss that due to the independence of eye artifact sources, regression-based correction methods inevitably over- or under-correct individual artifact components, while ICA is in principle suited to address such mixtures of different types of artifacts. Finally, we propose an algorithm, which uses eye tracker information to objectively identify eye-artifact related ICA-components (ICs) in an automated manner. In the data presented here, the algorithm performed very similar to human experts when those were given both, the topographies of the ICs and their respective activations in a large amount of trials. Moreover it performed more reliable and almost twice as effective than human experts

Multipulse control of saccadic eye movements

NASA Technical Reports Server (NTRS)

Lehman, S. L.; Stark, L.

1981-01-01

We present three conclusions regarding the neural control of saccadic eye movements, resulting from comparisons between recorded movements and computer simulations. The controller signal to the muscles is probably a multipulse-step. This kind of signal drives the fastest model trajectories. Finally, multipulse signals explain differences between model and electrophysiological results.

Eye Movement Abnormalities in Joubert Syndrome

PubMed Central

Weiss, Avery H.; Doherty, Dan; Parisi, Melissa; Shaw, Dennis; Glass, Ian; Phillips, James O.

2011-01-01

Purpose Joubert syndrome is a genetic disorder characterized by hypoplasia of the midline cerebellum and deficiency of crossed connections between neural structures in the brain stem that control eye movements. The goal of the study was to quantify the eye movement abnormalities that occur in Joubert syndrome. Methods Eye movements were recorded in response to stationary stimuli and stimuli designed to elicit smooth pursuit, saccades, optokinetic nystagmus (OKN), vestibulo-ocular reflex (VOR), and vergence using video-oculography or Skalar search coils in 8 patients with Joubert syndrome. All patients underwent high-resolution magnetic resonance imaging (MRI). Results All patients had the highly characteristic molar tooth sign on brain MRI. Six patients had conjugate pendular (n = 4) or see-saw nystagmus (n = 2); gaze holding was stable in four patients. Smooth-pursuit gains were 0.28 to 1.19, 0.11 to 0.68, and 0.33 to 0.73 at peak stimulus velocities of 10, 20, and 30 deg/s in six patients; smooth pursuit could not be elicited in four patients. Saccade gains in five patients ranged from 0.35 to 0.91 and velocities ranged from 60.9 to 259.5 deg/s. Targeted saccades could not be elicited in five patients. Horizontal OKN gain was uniformly reduced across gratings drifted at velocities of 15, 30, and 45 deg/s. VOR gain was 0.8 or higher and phase appropriate in three of seven subjects; VOR gain was 0.3 or less and phase was indeterminate in four subjects. Conclusions The abnormalities in gaze-holding and eye movements are consistent with the distributed abnormalities of midline cerebellum and brain stem regions associated with Joubert syndrome. PMID:19443711

Anticipatory Eye Movements in Interleaving Templates of Human Behavior

NASA Technical Reports Server (NTRS)

Matessa, Michael

2004-01-01

Performance modeling has been made easier by architectures which package psychological theory for reuse at useful levels of abstraction. CPM-GOMS uses templates of behavior to package at a task level (e.g., mouse move-click, typing) predictions of lower-level cognitive, perceptual, and motor resource use. CPM-GOMS also has a theory for interleaving resource use between templates. One example of interleaving is anticipatory eye movements. This paper describes the use of ACT-Stitch, a framework for translating CPM-GOMS templates and interleaving theory into ACT-R, to model anticipatory eye movements in skilled behavior. The anticipatory eye movements explain performance in a well-practiced perceptual/motor task, and the interleaving theory is supported with results from an eye-tracking experiment.

Performing saccadic eye movements or blinking improves postural control.

PubMed

Rougier, Patrice; Garin, Mélanie

2007-07-01

To determine the relationship between eye movement and postural control on an undisturbed upright stance maintenance protocol, 15 young, healthy individuals were tested in various conditions. These conditions included imposed blinking patterns and horizontal and vertical saccadic eye movements. The directions taken by the center of pressure (CP) were recorded via a force platform on which the participants remained in an upright position. The CP trajectories were used to estimate, via a low-pass filter, the vertically projected movements of the center of gravity (CGv) and consequently the difference CP-CGv. An analysis of the frequency shows that regular bilateral blinking does not produce a significant change in postural control. In contrast, performing saccadic eye movements induces some reduced amplitude for both basic CGv and CP-CGv movements principally along the antero-posterior axis. The present result supports the theory that some ocular movements may modify postural control in the maintenance of the upright standing position in human participants.

Apathy in rapid eye movement sleep behaviour disorder is common and under-recognized.

PubMed

Barber, T R; Muhammed, K; Drew, D; Lawton, M; Crabbe, M; Rolinski, M; Quinnell, T; Zaiwalla, Z; Ben-Shlomo, Y; Husain, M; Hu, M T M

2018-03-01

Apathy is an important neuropsychiatric feature of Parkinson's disease (PD), which often emerges before the onset of motor symptoms. Patients with rapid eye movement sleep behaviour disorder (RBD) have a high probability of developing PD in future. Neuropsychiatric problems are common in RBD, but apathy has not previously been detailed in this key prodromal population. Eighty-eight patients with polysomnographically proven RBD, 65 patients with PD and 33 controls were assessed for apathy using the Lille Apathy Rating Scale. Cognition and depression were also quantified. The sensitivity of the Unified Parkinson's Disease Rating Scale screening questions for apathy and depression was calculated. A total of 46% of patients with RBD were apathetic, compared with 31% of patients with PD in our sample. Most patients with RBD with depression were apathetic but more than half of apathetic patients were not depressed. The sensitivity of the single Unified Parkinson's Disease Rating Scale screening question was only 33% for mild apathy and 50% for severe apathy. Apathy is common in RBD and is underestimated by a single self-report question. Recognition of apathy as a distinct neuropsychiatric feature in RBD could aid targeted treatment interventions and might contribute to the understanding of prodromal PD. © 2017 The Authors. European Journal of Neurology published by John Wiley & Sons Ltd on behalf of European Academy of Neurology.

Impulse control disorder and rapid eye movement sleep behavior disorder in Parkinson's disease.

PubMed

Bayard, Sophie; Dauvilliers, Yves; Yu, Huan; Croisier-Langenier, Muriel; Rossignol, Alexia; Charif, Mahmoud; Geny, Christian; Carlander, Bertrand; Cochen De Cock, Valérie

2014-12-01

The relationship between ICD and RBD is still not yet understood and the results from the current literature are contradictory in PD. We aimed to explore the association between rapid eye movement (REM) sleep behavior disorder (RBD) and impulse control disorder in Parkinson's disease. Ninety-eight non-demented patients with Parkinson's disease underwent one night of video-polysomnography recording. The diagnosis of RBD was established according to clinical and polysomnographic criteria. Impulse control disorders were determined by a gold standard, semi-structured diagnostic interview. Half of the patients (n = 49) reported clinical history of RBD while polysomnographic diagnosis of RBD was confirmed in 31.6% of the patients (n = 31). At least one impulse control disorder was identified in 21.4% of patients, 22.6% with RBD and 20.9% without. Logistic regression controlling for potential confounders indicated that both clinical RBD (OR = 0.34, 95% CI = 0.07-1.48, P = 0.15) and polysomnographic confirmed RBD diagnoses (OR = 0.1.28, 95% CI = 0.31-5.33, P = 0.34) were not associated with impulse control disorder. In Parkinson's disease, REM Sleep Behavior Disorder is not associated with impulse control disorder. The results of our study do not support the notion that PSG-confirmed RBD and ICD share a common pathophysiology. Copyright © 2014 Elsevier Ltd. All rights reserved.

Constraining eye movement in individuals with Parkinson's disease during walking turns.

PubMed

Ambati, V N Pradeep; Saucedo, Fabricio; Murray, Nicholas G; Powell, Douglas W; Reed-Jones, Rebecca J

2016-10-01

Walking and turning is a movement that places individuals with Parkinson's disease (PD) at increased risk for fall-related injury. However, turning is an essential movement in activities of daily living, making up to 45 % of the total steps taken in a given day. Hypotheses regarding how turning is controlled suggest an essential role of anticipatory eye movements to provide feedforward information for body coordination. However, little research has investigated control of turning in individuals with PD with specific consideration for eye movements. The purpose of this study was to examine eye movement behavior and body segment coordination in individuals with PD during walking turns. Three experimental groups, a group of individuals with PD, a group of healthy young adults (YAC), and a group of healthy older adults (OAC), performed walking and turning tasks under two visual conditions: free gaze and fixed gaze. Whole-body motion capture and eye tracking characterized body segment coordination and eye movement behavior during walking trials. Statistical analysis revealed significant main effects of group (PD, YAC, and OAC) and visual condition (free and fixed gaze) on timing of segment rotation and horizontal eye movement. Within group comparisons, revealed timing of eye and head movement was significantly different between the free and fixed gaze conditions for YAC (p < 0.001) and OAC (p < 0.05), but not for the PD group (p > 0.05). In addition, while intersegment timings (reflecting segment coordination) were significantly different for YAC and OAC during free gaze (p < 0.05), they were not significantly different in PD. These results suggest individuals with PD do not make anticipatory eye and head movements ahead of turning and that this may result in altered segment coordination during turning. As such, eye movements may be an important addition to training programs for those with PD, possibly promoting better coordination during turning and

Binocular vision and eye movement disorders in older adults.

PubMed

Leat, Susan J; Chan, Lisa Li-Li; Maharaj, Priya-Devi; Hrynchak, Patricia K; Mittelstaedt, Andrea; Machan, Carolyn M; Irving, Elizabeth L

2013-05-31

To determine the prevalence of binocular vision (BV) and eye movement disorders in a clinic population of older adults. Retrospective clinic data were abstracted from files of 500 older patients seen at the University of Waterloo Optometry Clinic over a 1-year period. Stratified sampling gave equal numbers of patients in the 60 to 69, 70 to 79, and 80+ age groups. Data included age, general and ocular history and symptoms, use of antidepressants, a habit of smoking, refraction, visual acuity, BV and eye movement status for the most recent full oculo-visual assessment, and an assessment 10 years prior. The prevalence of any BV or eye movement abnormal test (AT) result, defined as a test result outside the normal range, was determined. This included strabismus (any) or phoria; incomitancy; poor pursuits; and remote near point of convergence (NPC). The prevalence of significant BV disorders (diagnostic entities, i.e., a clinical condition that may need treatment and may have functional implications) was also determined. The prevalence of any BV or eye movement at was 41%, 44%, and 51% in the 60 to 69, 70 to 79, and 80+ age groups, respectively. These figures were lower for 10 years earlier: 31%, 36%, and 40% for ages 50 to 59, 60 to 69, and 70+, respectively. The prevalence of any BV or eye movement disorder was 27%, 30%, and 38% for the three age groups and 17%, 19%, and 24% for 10 years prior. Age and use of antidepressants most commonly predicted BV or eye movement AT or disorder. BV disorders are common among older adults.

Retinal image registration for eye movement estimation.

PubMed

Kolar, Radim; Tornow, Ralf P; Odstrcilik, Jan

2015-01-01

This paper describes a novel methodology for eye fixation measurement using a unique videoophthalmoscope setup and advanced image registration approach. The representation of the eye movements via Poincare plot is also introduced. The properties, limitations and perspective of this methodology are finally discussed.

Eye Movement Patterns of the Elderly during Stair Descent:Effect of Illumination

NASA Astrophysics Data System (ADS)

Kasahara, Satoko; Okabe, Sonoko; Nakazato, Naoko; Ohno, Yuko

The relationship between the eye movement pattern during stair descent and illumination was studied in 4 elderly people in comparison with that in 5 young people. The illumination condition was light (85.0±30.9 lx) or dark (0.7±0.3 lx), and data of eye movements were obtained using an eye mark recorder. A flight of 15 steps was used for the experiment, and data on 3 steps in the middle, on which the descent movements were stabilized, were analyzed. The elderly subjects pointed their eyes mostly directly in front in the facial direction regardless of the illumination condition, but the young subjects tended to look down under the light condition. The young subjects are considered to have confirmed the safety of the front by peripheral vision, checked the stepping surface by central vision, and still maintained the upright position without leaning forward during stair descent. The elderly subjects, in contrast, always looked at the visual target by central vision even under the light condition and leaned forward. The range of eye movements was larger vertically than horizontally in both groups, and a characteristic eye movement pattern of repeating a vertical shuttle movement synchronous with descent of each step was observed. Under the dark condition, the young subjects widened the range of vertical eye movements and reduced duration of fixation. The elderly subjects showed no change in the range of eye movements but increased duration of fixation during stair descent. These differences in the eye movements are considered to be compensatory reactions to narrowing of the vertical visual field, reduced dark adaptation, and reduced dynamic visual acuity due to aging. These characteristics of eye movements of the elderly lead to an anteriorly leaned posture and lack of attention to the front during stair descent.

How detrimental is eye movement during photorefractive keratectomy to the patient's postoperative vision?

NASA Astrophysics Data System (ADS)

Taylor, Natalie M.; van Saarloos, Paul P.; Eikelboom, Robert H.

2000-06-01

This study aimed to gauge the effect of the patient's eye movement during Photo Refractive Keratectomy (PRK) on post- operative vision. A computer simulation of both the PRK procedure and the visual outcome has been performed. The PRK simulation incorporated the pattern of movement of the laser beam to perform a given correction, the beam characteristics, an initial corneal profile, and an eye movement scenario; and generated the corrected corneal profile. The regrowth of the epithelium was simulated by selecting the smoothing filter which, when applied to a corrected cornea with no patient eye movement, produced similar ray tracing results to the original corneal model. Ray tracing several objects, such as letters of various contrast and sizes was performed to assess the quality of the post-operative vision. Eye movement scenarios included no eye movement, constant decentration and normally distributed random eye movement of varying magnitudes. Random eye movement of even small amounts, such as 50 microns reduces the contrast sensitivity of the image. Constant decentration decenters the projected image on the retina, and in extreme cases can lead to astigmatism. Eye movements of the magnitude expected during laser refractive surgery have minimal effect on the final visual outcome.

Extracting information of fixational eye movements through pupil tracking

NASA Astrophysics Data System (ADS)

Xiao, JiangWei; Qiu, Jian; Luo, Kaiqin; Peng, Li; Han, Peng

2018-01-01

Human eyes are never completely static even when they are fixing a stationary point. These irregular, small movements, which consist of micro-tremors, micro-saccades and drifts, can prevent the fading of the images that enter our eyes. The importance of researching the fixational eye movements has been experimentally demonstrated recently. However, the characteristics of fixational eye movements and their roles in visual process have not been explained clearly, because these signals can hardly be completely extracted by now. In this paper, we developed a new eye movement detection device with a high-speed camera. This device includes a beam splitter mirror, an infrared light source and a high-speed digital video camera with a frame rate of 200Hz. To avoid the influence of head shaking, we made the device wearable by fixing the camera on a safety helmet. Using this device, the experiments of pupil tracking were conducted. By localizing the pupil center and spectrum analysis, the envelope frequency spectrum of micro-saccades, micro-tremors and drifts are shown obviously. The experimental results show that the device is feasible and effective, so that the device can be applied in further characteristic analysis.

Semantic guidance of eye movements in real-world scenes

PubMed Central

Hwang, Alex D.; Wang, Hsueh-Cheng; Pomplun, Marc

2011-01-01

The perception of objects in our visual world is influenced by not only their low-level visual features such as shape and color, but also their high-level features such as meaning and semantic relations among them. While it has been shown that low-level features in real-world scenes guide eye movements during scene inspection and search, the influence of semantic similarity among scene objects on eye movements in such situations has not been investigated. Here we study guidance of eye movements by semantic similarity among objects during real-world scene inspection and search. By selecting scenes from the LabelMe object-annotated image database and applying Latent Semantic Analysis (LSA) to the object labels, we generated semantic saliency maps of real-world scenes based on the semantic similarity of scene objects to the currently fixated object or the search target. An ROC analysis of these maps as predictors of subjects’ gaze transitions between objects during scene inspection revealed a preference for transitions to objects that were semantically similar to the currently inspected one. Furthermore, during the course of a scene search, subjects’ eye movements were progressively guided toward objects that were semantically similar to the search target. These findings demonstrate substantial semantic guidance of eye movements in real-world scenes and show its importance for understanding real-world attentional control. PMID:21426914

Semantic guidance of eye movements in real-world scenes.

PubMed

Hwang, Alex D; Wang, Hsueh-Cheng; Pomplun, Marc

2011-05-25

The perception of objects in our visual world is influenced by not only their low-level visual features such as shape and color, but also their high-level features such as meaning and semantic relations among them. While it has been shown that low-level features in real-world scenes guide eye movements during scene inspection and search, the influence of semantic similarity among scene objects on eye movements in such situations has not been investigated. Here we study guidance of eye movements by semantic similarity among objects during real-world scene inspection and search. By selecting scenes from the LabelMe object-annotated image database and applying latent semantic analysis (LSA) to the object labels, we generated semantic saliency maps of real-world scenes based on the semantic similarity of scene objects to the currently fixated object or the search target. An ROC analysis of these maps as predictors of subjects' gaze transitions between objects during scene inspection revealed a preference for transitions to objects that were semantically similar to the currently inspected one. Furthermore, during the course of a scene search, subjects' eye movements were progressively guided toward objects that were semantically similar to the search target. These findings demonstrate substantial semantic guidance of eye movements in real-world scenes and show its importance for understanding real-world attentional control. Copyright © 2011 Elsevier Ltd. All rights reserved.

Lossless compression of otoneurological eye movement signals.

PubMed

Tossavainen, Timo; Juhola, Martti

2002-12-01

We studied the performance of several lossless compression algorithms on eye movement signals recorded in otoneurological balance and other physiological laboratories. Despite the wide use of these signals their compression has not been studied prior to our research. The compression methods were based on the common model of using a predictor to decorrelate the input and using an entropy coder to encode the residual. We found that these eye movement signals recorded at 400 Hz and with 13 bit amplitude resolution could losslessly be compressed with a compression ratio of about 2.7.

Modelling eye movements in a categorical search task

PubMed Central

Zelinsky, Gregory J.; Adeli, Hossein; Peng, Yifan; Samaras, Dimitris

2013-01-01

We introduce a model of eye movements during categorical search, the task of finding and recognizing categorically defined targets. It extends a previous model of eye movements during search (target acquisition model, TAM) by using distances from an support vector machine classification boundary to create probability maps indicating pixel-by-pixel evidence for the target category in search images. Other additions include functionality enabling target-absent searches, and a fixation-based blurring of the search images now based on a mapping between visual and collicular space. We tested this model on images from a previously conducted variable set-size (6/13/20) present/absent search experiment where participants searched for categorically defined teddy bear targets among random category distractors. The model not only captured target-present/absent set-size effects, but also accurately predicted for all conditions the numbers of fixations made prior to search judgements. It also predicted the percentages of first eye movements during search landing on targets, a conservative measure of search guidance. Effects of set size on false negative and false positive errors were also captured, but error rates in general were overestimated. We conclude that visual features discriminating a target category from non-targets can be learned and used to guide eye movements during categorical search. PMID:24018720

Eye movement training is most effective when it involves a task-relevant sensorimotor decision.

PubMed

Fooken, Jolande; Lalonde, Kathryn M; Mann, Gurkiran K; Spering, Miriam

2018-04-01

Eye and hand movements are closely linked when performing everyday actions. We conducted a perceptual-motor training study to investigate mutually beneficial effects of eye and hand movements, asking whether training in one modality benefits performance in the other. Observers had to predict the future trajectory of a briefly presented moving object, and intercept it at its assumed location as accurately as possible with their finger. Eye and hand movements were recorded simultaneously. Different training protocols either included eye movements or a combination of eye and hand movements with or without external performance feedback. Eye movement training did not transfer across modalities: Irrespective of feedback, finger interception accuracy and precision improved after training that involved the hand, but not after isolated eye movement training. Conversely, eye movements benefited from hand movement training or when external performance feedback was given, thus improving only when an active interceptive task component was involved. These findings indicate only limited transfer across modalities. However, they reveal the importance of creating a training task with an active sensorimotor decision to improve the accuracy and precision of eye and hand movements.

Exogenous orienting of attention depends upon the ability to execute eye movements.

PubMed

Smith, Daniel T; Rorden, Chris; Jackson, Stephen R

2004-05-04

Shifts of attention can be made overtly by moving the eyes or covertly with attention being allocated to a region of space that does not correspond to the current direction of gaze. However, the precise relationship between eye movements and the covert orienting of attention remains controversial. The influential premotor theory proposes that the covert orienting of attention is produced by the programming of (unexecuted) eye movements and thus predicts a strong relationship between the ability to execute eye movements and the operation of spatial attention. Here, we demonstrate for the first time that impaired spatial attention is observed in an individual (AI) who is neurologically healthy but who cannot execute eye movements as a result of a congenital impairment in the elasticity of her eye muscles. This finding provides direct support for the role of the eye-movement system in the covert orienting of attention and suggests that whereas intact cortical structures may be necessary for normal attentional reflexes, they are not sufficient. The ability to move our eyes is essential for the development of normal patterns of spatial attention.

Basal Ganglia Neuronal Activity during Scanning Eye Movements in Parkinson’s Disease

PubMed Central

Sieger, Tomáš; Bonnet, Cecilia; Serranová, Tereza; Wild, Jiří; Novák, Daniel; Růžička, Filip; Urgošík, Dušan; Růžička, Evžen; Gaymard, Bertrand; Jech, Robert

2013-01-01

The oculomotor role of the basal ganglia has been supported by extensive evidence, although their role in scanning eye movements is poorly understood. Nineteen Parkinsońs disease patients, which underwent implantation of deep brain stimulation electrodes, were investigated with simultaneous intraoperative microelectrode recordings and single channel electrooculography in a scanning eye movement task by viewing a series of colored pictures selected from the International Affective Picture System. Four patients additionally underwent a visually guided saccade task. Microelectrode recordings were analyzed selectively from the subthalamic nucleus, substantia nigra pars reticulata and from the globus pallidus by the WaveClus program which allowed for detection and sorting of individual neurons. The relationship between neuronal firing rate and eye movements was studied by crosscorrelation analysis. Out of 183 neurons that were detected, 130 were found in the subthalamic nucleus, 30 in the substantia nigra and 23 in the globus pallidus. Twenty percent of the neurons in each of these structures showed eye movement-related activity. Neurons related to scanning eye movements were mostly unrelated to the visually guided saccades. We conclude that a relatively large number of basal ganglia neurons are involved in eye motion control. Surprisingly, neurons related to scanning eye movements differed from neurons activated during saccades suggesting functional specialization and segregation of both systems for eye movement control. PMID:24223158

Mortality and Its Risk Factors in Patients with Rapid Eye Movement Sleep Behavior Disorder.

PubMed

Zhou, Junying; Zhang, Jihui; Lam, Siu Ping; Mok, Vincent; Chan, Anne; Li, Shirley Xin; Liu, Yaping; Tang, Xiangdong; Yung, Wing Ho; Wing, Yun Kwok

2016-08-01

To determine the mortality and its risk factors in patients with rapid eye movement (REM) sleep behavior disorder (RBD). A total of 205 consecutive patients with video-polysomnography confirmed RBD (mean age = 66.4 ± 10.0 y, 78.5% males) were recruited. Medical records and death status were systematically reviewed in the computerized records of the health care system. Standardized mortality ratio (SMR) was used to calculate the risk ratio of mortality in RBD with reference to the general population. Forty-three patients (21.0%) died over a mean follow-up period of 7.1 ± 4.5 y. The SMR was not increased in the overall sample, SMR (95% confidence interval [CI]) = 1.00 (0.73-1.33). However, SMR (95% CI) increased to 1.80 (1.21-2.58) and 1.75 (1.11-2.63) for RBD patients in whom neurodegenerative diseases and dementia, respectively, eventually developed. In the Cox regression model, mortality risk was significantly associated with age (hazard ratio [HR] = 1.05; 95% CI, 1.01-1.10), living alone (HR = 2.04; 95% CI, 1.39-2.99), chronic obstructive pulmonary disease (HR = 3.38; 95% CI, 1.21-9.46), cancer (HR = 10.09; 95% CI, 2.65-38.42), periodic limb movements during sleep (HR = 3.06; 95% CI, 1.50-6.24), and development of neurodegenerative diseases (HR = 2.84; 95% CI, 1.47-5.45) and dementia (HR = 2.66; 95% CI, 1.39-5.08). Patients with RBD have a higher mortality rate than the general population only if neurodegenerative diseases develop. Several risk factors on clinical and sleep aspects are associated with mortality in RBD patients. Our findings underscore the necessity of timely neuroprotective interventions in the early phase of RBD before the development of neurodegenerative diseases. © 2016 Associated Professional Sleep Societies, LLC.

Effects of diphenhydramine on human eye movements.

PubMed

Hopfenbeck, J R; Cowley, D S; Radant, A; Greenblatt, D J; Roy-Byrne, P P

1995-04-01

Peak saccadic eye movement velocity (SEV) and average smooth pursuit gain (SP) are reduced in a dose-dependent manner by diazepam and provide reliable, quantitative measures of benzodiazepine agonist effects. To evaluate the specificity of these eye movement effects for agents acting at the central GABA-benzodiazepine receptor complex and the role of sedation in benzodiazepine effects, we studied eye movement effects of diphenhydramine, a sedating drug which does not act at the GABA-benzodiazepine receptor complex. Ten healthy males, aged 19-28 years, with no history of axis I psychiatric disorders or substance abuse, received 50 mg/70 kg intravenous diphenhydramine or a similar volume of saline on separate days 1 week apart. SEV, saccade latency and accuracy, SP, self-rated sedation, and short-term memory were assessed at baseline and at 5, 15, 30, 45, 60, 90 and 120 min after drug administration. Compared with placebo, diphenhydramine produced significant SEV slowing, and increases in saccade latency and self-rated sedation. There was no significant effect of diphenhydramine on smooth pursuit gain, saccade accuracy, or short-term memory. These results suggest that, like diazepam, diphenhydramine causes sedation, SEV slowing, and an increase in saccade latency. Since the degree of diphenhydramine-induced sedation was not correlated with changes in SEV or saccade latency, slowing of saccadic eye movements is unlikely to be attributable to sedation alone. Unlike diazepam, diphenhydramine does not impair smooth pursuit gain, saccadic accuracy, or memory. Different neurotransmitter systems may influence the neural pathways involved in SEV and smooth pursuit again.

An ocular biomechanic model for dynamic simulation of different eye movements.

PubMed

Iskander, J; Hossny, M; Nahavandi, S; Del Porto, L

2018-04-11

Simulating and analysing eye movement is useful for assessing visual system contribution to discomfort with respect to body movements, especially in virtual environments where simulation sickness might occur. It can also be used in the design of eye prosthesis or humanoid robot eye. In this paper, we present two biomechanic ocular models that are easily integrated into the available musculoskeletal models. The model was previously used to simulate eye-head coordination. The models are used to simulate and analyse eye movements. The proposed models are based on physiological and kinematic properties of the human eye. They incorporate an eye-globe, orbital suspension tissues and six muscles with their connective tissues (pulleys). Pulleys were incorporated in rectus and inferior oblique muscles. The two proposed models are the passive pulleys and the active pulleys models. Dynamic simulations of different eye movements, including fixation, saccade and smooth pursuit, are performed to validate both models. The resultant force-length curves of the models were similar to the experimental data. The simulation results show that the proposed models are suitable to generate eye movement simulations with results comparable to other musculoskeletal models. The maximum kinematic root mean square error (RMSE) is 5.68° and 4.35° for the passive and active pulley models, respectively. The analysis of the muscle forces showed realistic muscle activation with increased muscle synergy in the active pulley model. Copyright © 2018 Elsevier Ltd. All rights reserved.

Predicting the Valence of a Scene from Observers’ Eye Movements

PubMed Central

R.-Tavakoli, Hamed; Atyabi, Adham; Rantanen, Antti; Laukka, Seppo J.; Nefti-Meziani, Samia; Heikkilä, Janne

2015-01-01

Multimedia analysis benefits from understanding the emotional content of a scene in a variety of tasks such as video genre classification and content-based image retrieval. Recently, there has been an increasing interest in applying human bio-signals, particularly eye movements, to recognize the emotional gist of a scene such as its valence. In order to determine the emotional category of images using eye movements, the existing methods often learn a classifier using several features that are extracted from eye movements. Although it has been shown that eye movement is potentially useful for recognition of scene valence, the contribution of each feature is not well-studied. To address the issue, we study the contribution of features extracted from eye movements in the classification of images into pleasant, neutral, and unpleasant categories. We assess ten features and their fusion. The features are histogram of saccade orientation, histogram of saccade slope, histogram of saccade length, histogram of saccade duration, histogram of saccade velocity, histogram of fixation duration, fixation histogram, top-ten salient coordinates, and saliency map. We utilize machine learning approach to analyze the performance of features by learning a support vector machine and exploiting various feature fusion schemes. The experiments reveal that ‘saliency map’, ‘fixation histogram’, ‘histogram of fixation duration’, and ‘histogram of saccade slope’ are the most contributing features. The selected features signify the influence of fixation information and angular behavior of eye movements in the recognition of the valence of images. PMID:26407322

Baseline Levels of Rapid Eye Movement Sleep May Protect Against Excessive Activity in Fear-Related Neural Circuitry.

PubMed

Lerner, Itamar; Lupkin, Shira M; Sinha, Neha; Tsai, Alan; Gluck, Mark A

2017-11-15

Sleep, and particularly rapid eye movement sleep (REM), has been implicated in the modulation of neural activity following fear conditioning and extinction in both human and animal studies. It has long been presumed that such effects play a role in the formation and persistence of posttraumatic stress disorder, of which sleep impairments are a core feature. However, to date, few studies have thoroughly examined the potential effects of sleep prior to conditioning on subsequent acquisition of fear learning in humans. Furthermore, these studies have been restricted to analyzing the effects of a single night of sleep-thus assuming a state-like relationship between the two. In the current study, we used long-term mobile sleep monitoring and functional neuroimaging (fMRI) to explore whether trait-like variations in sleep patterns, measured in advance in both male and female participants, predict subsequent patterns of neural activity during fear learning. Our results indicate that higher baseline levels of REM sleep predict reduced fear-related activity in, and connectivity between, the hippocampus, amygdala and ventromedial PFC during conditioning. Additionally, skin conductance responses (SCRs) were weakly correlated to the activity in the amygdala. Conversely, there was no direct correlation between REM sleep and SCRs, indicating that REM may only modulate fear acquisition indirectly. In a follow-up experiment, we show that these results are replicable, though to a lesser extent, when measuring sleep over a single night just before conditioning. As such, baseline sleep parameters may be able to serve as biomarkers for resilience, or lack thereof, to trauma. SIGNIFICANCE STATEMENT Numerous studies over the past two decades have established a clear role of sleep in fear-learning processes. However, previous work has focused on the effects of sleep following fear acquisition, thus neglecting the potential effects of baseline sleep levels on the acquisition itself. The

Individual Differences in Impulsivity Predict Anticipatory Eye Movements

PubMed Central

Cirilli, Laetitia; de Timary, Philippe; Lefèvre, Phillipe; Missal, Marcus

2011-01-01

Impulsivity is the tendency to act without forethought. It is a personality trait commonly used in the diagnosis of many psychiatric diseases. In clinical practice, impulsivity is estimated using written questionnaires. However, answers to questions might be subject to personal biases and misinterpretations. In order to alleviate this problem, eye movements could be used to study differences in decision processes related to impulsivity. Therefore, we investigated correlations between impulsivity scores obtained with a questionnaire in healthy subjects and characteristics of their anticipatory eye movements in a simple smooth pursuit task. Healthy subjects were asked to answer the UPPS questionnaire (Urgency Premeditation Perseverance and Sensation seeking Impulsive Behavior scale), which distinguishes four independent dimensions of impulsivity: Urgency, lack of Premeditation, lack of Perseverance, and Sensation seeking. The same subjects took part in an oculomotor task that consisted of pursuing a target that moved in a predictable direction. This task reliably evoked anticipatory saccades and smooth eye movements. We found that eye movement characteristics such as latency and velocity were significantly correlated with UPPS scores. The specific correlations between distinct UPPS factors and oculomotor anticipation parameters support the validity of the UPPS construct and corroborate neurobiological explanations for impulsivity. We suggest that the oculomotor approach of impulsivity put forth in the present study could help bridge the gap between psychiatry and physiology. PMID:22046334

Distractor Interference during Smooth Pursuit Eye Movements

ERIC Educational Resources Information Center

Spering, Miriam; Gegenfurtner, Karl R.; Kerzel, Dirk

2006-01-01

When 2 targets for pursuit eye movements move in different directions, the eye velocity follows the vector average (S. G. Lisberger & V. P. Ferrera, 1997). The present study investigates the mechanisms of target selection when observers are instructed to follow a predefined horizontal target and to ignore a moving distractor stimulus. Results show…

Paraneoplastic disorders of eye movements

PubMed Central

Wray, Shirley H.; Dalmau, Josep; Chen, Athena; King, Susan; Leigh, R. John

2011-01-01

Paraneoplastic syndromes affecting the brainstem and cerebellum are reported to cause a variety of abnormalities of eye movements. Recent studies have begun to account for the mechanisms underlying several syndromes, characterized by opsoclonus, slow, or dysmetric saccades, as well as downbeat nystagmus. We provide evidence that upbeat nystagmus in a patient with pancreatic cancer reflected a cerebellar-induced imbalance of otolithic pathways: she showed marked retropulsion, and her nystagmus was dependent on head position, being absent when supine, and suppressed with convergence. In addition to anti-Hu antibodies, we demonstrated antibodies to a novel neuronal cell surface antigen. Taken with other recent studies, our findings suggest that paraneoplastic syndromes arise due to antibodies against surface neuronal antigens, including receptors and channels. Abnormal eye movements in paraneoplastic syndromes offer insights into the pathogenesis of these disorders and the opportunity to test potential therapies, such as new drugs with effects on neuronal channels. PMID:21951005

Hypothesized eye movements of neurolinguistic programming: a statistical artifact.

PubMed

Farmer, A; Rooney, R; Cunningham, J R

1985-12-01

Neurolinguistic programming's hypothesized eye-movements were measured independently from videotapes of 30 subjects, aged 15 to 76 yr., who were asked to recall visual pictures, recorded audio sounds, and textural objects. chi 2 indicated that subjects' responses were significantly different from those predicted. When chi 2 comparisons were weighted by number of eye positions assigned to each modality (3 visual, 3 auditory, 1 kinesthetic), subjects' responses did not differ significantly from the expected pattern. These data indicate that the eye-movement hypothesis may represent randomly occurring rather than sensory-modality-related positions.

Combining EEG and eye movement recording in free viewing: Pitfalls and possibilities.

PubMed

Nikolaev, Andrey R; Meghanathan, Radha Nila; van Leeuwen, Cees

2016-08-01

Co-registration of EEG and eye movement has promise for investigating perceptual processes in free viewing conditions, provided certain methodological challenges can be addressed. Most of these arise from the self-paced character of eye movements in free viewing conditions. Successive eye movements occur within short time intervals. Their evoked activity is likely to distort the EEG signal during fixation. Due to the non-uniform distribution of fixation durations, these distortions are systematic, survive across-trials averaging, and can become a source of confounding. We illustrate this problem with effects of sequential eye movements on the evoked potentials and time-frequency components of EEG and propose a solution based on matching of eye movement characteristics between experimental conditions. The proposal leads to a discussion of which eye movement characteristics are to be matched, depending on the EEG activity of interest. We also compare segmentation of EEG into saccade-related epochs relative to saccade and fixation onsets and discuss the problem of baseline selection and its solution. Further recommendations are given for implementing EEG-eye movement co-registration in free viewing conditions. By resolving some of the methodological problems involved, we aim to facilitate the transition from the traditional stimulus-response paradigm to the study of visual perception in more naturalistic conditions. Copyright © 2016 Elsevier Inc. All rights reserved.

Eye Movement as an Indicator of Sensory Components in Thought.

ERIC Educational Resources Information Center

Buckner, Michael; And Others

1987-01-01

Investigated Neuro-Linguistic Programming eye movement model's claim that specific eye movements are indicative of specific sensory components in thought. Agreement between students' (N=48) self-reports and trained observers' records support visual and auditory portions of model; do not support kinesthetic portion. Interrater agreement supports…

Apnea-induced rapid eye movement sleep disruption impairs human spatial navigational memory.

PubMed

Varga, Andrew W; Kishi, Akifumi; Mantua, Janna; Lim, Jason; Koushyk, Viachaslau; Leibert, David P; Osorio, Ricardo S; Rapoport, David M; Ayappa, Indu

2014-10-29

Hippocampal electrophysiology and behavioral evidence support a role for sleep in spatial navigational memory, but the role of particular sleep stages is less clear. Although rodent models suggest the importance of rapid eye movement (REM) sleep in spatial navigational memory, a similar role for REM sleep has never been examined in humans. We recruited subjects with severe obstructive sleep apnea (OSA) who were well treated and adherent with continuous positive airway pressure (CPAP). Restricting CPAP withdrawal to REM through real-time monitoring of the polysomnogram provides a novel way of addressing the role of REM sleep in spatial navigational memory with a physiologically relevant stimulus. Individuals spent two different nights in the laboratory, during which subjects performed timed trials before and after sleep on one of two unique 3D spatial mazes. One night of sleep was normally consolidated with use of therapeutic CPAP throughout, whereas on the other night, CPAP was reduced only in REM sleep, allowing REM OSA to recur. REM disruption via this method caused REM sleep reduction and significantly fragmented any remaining REM sleep without affecting total sleep time, sleep efficiency, or slow-wave sleep. We observed improvements in maze performance after a night of normal sleep that were significantly attenuated after a night of REM disruption without changes in psychomotor vigilance. Furthermore, the improvement in maze completion time significantly positively correlated with the mean REM run duration across both sleep conditions. In conclusion, we demonstrate a novel role for REM sleep in human memory formation and highlight a significant cognitive consequence of OSA. Copyright © 2014 the authors 0270-6474/14/3414571-07$15.00/0.

Acute enhancement of non-rapid eye movement sleep in rats after drinking water contaminated with cadmium chloride.

PubMed

Unno, Katsuya; Yamoto, Kurumi; Takeuchi, Kouhei; Kataoka, Aya; Ozaki, Tomoya; Mochizuki, Takatoshi; Honda, Kazuki; Miura, Nobuhiko; Ikeda, Masayuki

2014-02-01

Cadmium (Cd) is a heavy metal widely used or effused by industries. Serious environmental Cd pollution has been reported over the past two centuries, whereas the mechanisms underlying Cd-mediated diseases are not fully understood. Interestingly, an increase in reactive oxygen species (ROS) after Cd exposure has been shown. Our group has demonstrated that sleep is triggered via accumulation of ROS during neuronal activities, and we thus hypothesize the involvement of Cd poisoning in sleep-wake irregularities. In the present study, we analyzed the effects of Cd intake (1-100 ppm CdCl₂ in drinking water) on rats by monitoring sleep encephalograms and locomotor activities. The results demonstrated that 100 ppm CdCl₂ administration for 28 h was sufficient to increase non-rapid-eye-movement (non-REM) sleep and reduce locomotor activities during the night (the rat active phase). In contrast, free-running locomotor rhythms under constant dim red light and their re-entrainment to 12:12-h light/dark cycles were intact under chronic (1 month) 100 ppm CdCl₂ administrations, suggesting a limited influence on circadian clock movements at this dosage. The relative amount of oxidized glutathione increased in the brain after the 28-h 100 ppm CdCl₂ administrations similar to the levels in cultured astrocytes receiving H₂O₂ or CdCl₂ in culture medium. Therefore, we propose Cd-induced sleep as a consequence of oxidative stress. As oxidized glutathione is an endogenous sleep substance, we suggest that Cd rapidly induces sleepiness and influences activity performance by occupying intrinsic sleep-inducing mechanisms. In conclusion, we propose increased non-REM sleep during the active phase as an index of acute Cd exposure. Copyright © 2013 John Wiley & Sons, Ltd.

Understanding eye movements in face recognition using hidden Markov models.

PubMed

Chuk, Tim; Chan, Antoni B; Hsiao, Janet H

2014-09-16

We use a hidden Markov model (HMM) based approach to analyze eye movement data in face recognition. HMMs are statistical models that are specialized in handling time-series data. We conducted a face recognition task with Asian participants, and model each participant's eye movement pattern with an HMM, which summarized the participant's scan paths in face recognition with both regions of interest and the transition probabilities among them. By clustering these HMMs, we showed that participants' eye movements could be categorized into holistic or analytic patterns, demonstrating significant individual differences even within the same culture. Participants with the analytic pattern had longer response times, but did not differ significantly in recognition accuracy from those with the holistic pattern. We also found that correct and wrong recognitions were associated with distinctive eye movement patterns; the difference between the two patterns lies in the transitions rather than locations of the fixations alone. © 2014 ARVO.

Rapid micromotor-based naked-eye immunoassay.

PubMed

de Ávila, Berta Esteban-Fernández; Zhao, Mingjiao; Campuzano, Susana; Ricci, Francesco; Pingarrón, José M; Mascini, Marcello; Wang, Joseph

2017-05-15

A dynamic micromotor-based immunoassay, exemplified by cortisol detection, based on the use of tubular micromotors functionalized with a specific antibody is described. The use of antibody-functionalized micromotors offers huge acceleration of both direct and competitive cortisol immunoassays, along with greatly enhanced sensitivity of direct and competitive immunoassays. The dramatically improved speed and sensitivity reflect the greatly increased likelihood of antibody-cortisol contacts and fluid mixing associated with the dynamic movement of these microtube motors and corresponding bubble generation that lead to a highly efficient and rapid recognition process. Rapid naked-eye detection of cortisol in the sample is achieved in connection to use of horseradish peroxidase (HRP) tag and TMB/H 2 O 2 system. Key parameters of the competitive immunoassay (e.g., incubation time and reaction volume) were optimized. This fast visual micromotor-based sensing approach enables "on the move" specific detection of the target cortisol down to 0.1μgmL -1 in just 2min, using ultrasmall (50µL) sample volumes. Copyright © 2017 Elsevier B.V. All rights reserved.

The Role of Eye Movement Driven Attention in Functional Strabismic Amblyopia

PubMed Central

2015-01-01

Strabismic amblyopia “blunt vision” is a developmental anomaly that affects binocular vision and results in lowered visual acuity. Strabismus is a term for a misalignment of the visual axes and is usually characterized by impaired ability of the strabismic eye to take up fixation. Such impaired fixation is usually a function of the temporally and spatially impaired binocular eye movements that normally underlie binocular shifts in visual attention. In this review, we discuss how abnormal eye movement function in children with misaligned eyes influences the development of normal binocular visual attention and results in deficits in visual function such as depth perception. We also discuss how eye movement function deficits in adult amblyopia patients can also lead to other abnormalities in visual perception. Finally, we examine how the nonamblyopic eye of an amblyope is also affected in strabismic amblyopia. PMID:25838941

Effects of bilateral eye movements on the retrieval of item, associative, and contextual information.

PubMed

Parker, Andrew; Relph, Sarah; Dagnall, Neil

2008-01-01

Two experiments are reported that investigate the effects of saccadic bilateral eye movements on the retrieval of item, associative, and contextual information. Experiment 1 compared the effects of bilateral versus vertical versus no eye movements on tests of item recognition, followed by remember-know responses and associative recognition. Supporting previous research, bilateral eye movements enhanced item recognition by increasing the hit rate and decreasing the false alarm rate. Analysis of remember-know responses indicated that eye movement effects were accompanied by increases in remember responses. The test of associative recognition found that bilateral eye movements increased correct responses to intact pairs and decreased false alarms to rearranged pairs. Experiment 2 assessed the effects of eye movements on the recall of intrinsic (color) and extrinsic (spatial location) context. Bilateral eye movements increased correct recall for both types of context. The results are discussed within the framework of dual-process models of memory and the possible neural underpinnings of these effects are considered.

Eye Movements Reveal the Influence of Event Structure on Reading Behavior.

PubMed

Swets, Benjamin; Kurby, Christopher A

2016-03-01

When we read narrative texts such as novels and newspaper articles, we segment information presented in such texts into discrete events, with distinct boundaries between those events. But do our eyes reflect this event structure while reading? This study examines whether eye movements during the reading of discourse reveal how readers respond online to event structure. Participants read narrative passages as we monitored their eye movements. Several measures revealed that event structure predicted eye movements. In two experiments, we found that both early and overall reading times were longer for event boundaries. We also found that regressive saccades were more likely to land on event boundaries, but that readers were less likely to regress out of an event boundary. Experiment 2 also demonstrated that tracking event structure carries a working memory load. Eye movements provide a rich set of online data to test the cognitive reality of event segmentation during reading. Copyright © 2015 Cognitive Science Society, Inc.

Removing the Interdependency between Horizontal and Vertical Eye-Movement Components in Electrooculograms

PubMed Central

Chang, Won-Du; Cha, Ho-Seung; Im, Chang-Hwan

2016-01-01

This paper introduces a method to remove the unwanted interdependency between vertical and horizontal eye-movement components in electrooculograms (EOGs). EOGs have been widely used to estimate eye movements without a camera in a variety of human-computer interaction (HCI) applications using pairs of electrodes generally attached either above and below the eye (vertical EOG) or to the left and right of the eyes (horizontal EOG). It has been well documented that the vertical EOG component has less stability than the horizontal EOG one, making accurate estimation of the vertical location of the eyes difficult. To address this issue, an experiment was designed in which ten subjects participated. Visual inspection of the recorded EOG signals showed that the vertical EOG component is highly influenced by horizontal eye movements, whereas the horizontal EOG is rarely affected by vertical eye movements. Moreover, the results showed that this interdependency could be effectively removed by introducing an individual constant value. It is therefore expected that the proposed method can enhance the overall performance of practical EOG-based eye-tracking systems. PMID:26907271

Contextual effects on motion perception and smooth pursuit eye movements.

PubMed

Spering, Miriam; Gegenfurtner, Karl R

2008-08-15

Smooth pursuit eye movements are continuous, slow rotations of the eyes that allow us to follow the motion of a visual object of interest. These movements are closely related to sensory inputs from the visual motion processing system. To track a moving object in the natural environment, its motion first has to be segregated from the motion signals provided by surrounding stimuli. Here, we review experiments on the effect of the visual context on motion processing with a focus on the relationship between motion perception and smooth pursuit eye movements. While perception and pursuit are closely linked, we show that they can behave quite distinctly when required by the visual context.

Updating visual memory across eye movements for ocular and arm motor control.

PubMed

Thompson, Aidan A; Henriques, Denise Y P

2008-11-01

Remembered object locations are stored in an eye-fixed reference frame, so that every time the eyes move, spatial representations must be updated for the arm-motor system to reflect the target's new relative position. To date, studies have not investigated how the brain updates these spatial representations during other types of eye movements, such as smooth-pursuit. Further, it is unclear what information is used in spatial updating. To address these questions we investigated whether remembered locations of pointing targets are updated following smooth-pursuit eye movements, as they are following saccades, and also investigated the role of visual information in estimating eye-movement amplitude for updating spatial memory. Misestimates of eye-movement amplitude were induced when participants visually tracked stimuli presented with a background that moved in either the same or opposite direction of the eye before pointing or looking back to the remembered target location. We found that gaze-dependent pointing errors were similar following saccades and smooth-pursuit and that incongruent background motion did result in a misestimate of eye-movement amplitude. However, the background motion had no effect on spatial updating for pointing, but did when subjects made a return saccade, suggesting that the oculomotor and arm-motor systems may rely on different sources of information for spatial updating.

Fixational Eye Movements in the Earliest Stage of Metazoan Evolution

PubMed Central

Bielecki, Jan; Høeg, Jens T.; Garm, Anders

2013-01-01

All known photoreceptor cells adapt to constant light stimuli, fading the retinal image when exposed to an immobile visual scene. Counter strategies are therefore necessary to prevent blindness, and in mammals this is accomplished by fixational eye movements. Cubomedusae occupy a key position for understanding the evolution of complex visual systems and their eyes are assumedly subject to the same adaptive problems as the vertebrate eye, but lack motor control of their visual system. The morphology of the visual system of cubomedusae ensures a constant orientation of the eyes and a clear division of the visual field, but thereby also a constant retinal image when exposed to stationary visual scenes. Here we show that bell contractions used for swimming in the medusae refresh the retinal image in the upper lens eye of Tripedalia cystophora. This strongly suggests that strategies comparable to fixational eye movements have evolved at the earliest metazoan stage to compensate for the intrinsic property of the photoreceptors. Since the timing and amplitude of the rhopalial movements concur with the spatial and temporal resolution of the eye it circumvents the need for post processing in the central nervous system to remove image blur. PMID:23776673

Fixational eye movements in the earliest stage of metazoan evolution.

PubMed

Bielecki, Jan; Høeg, Jens T; Garm, Anders

2013-01-01

All known photoreceptor cells adapt to constant light stimuli, fading the retinal image when exposed to an immobile visual scene. Counter strategies are therefore necessary to prevent blindness, and in mammals this is accomplished by fixational eye movements. Cubomedusae occupy a key position for understanding the evolution of complex visual systems and their eyes are assumedly subject to the same adaptive problems as the vertebrate eye, but lack motor control of their visual system. The morphology of the visual system of cubomedusae ensures a constant orientation of the eyes and a clear division of the visual field, but thereby also a constant retinal image when exposed to stationary visual scenes. Here we show that bell contractions used for swimming in the medusae refresh the retinal image in the upper lens eye of Tripedalia cystophora. This strongly suggests that strategies comparable to fixational eye movements have evolved at the earliest metazoan stage to compensate for the intrinsic property of the photoreceptors. Since the timing and amplitude of the rhopalial movements concur with the spatial and temporal resolution of the eye it circumvents the need for post processing in the central nervous system to remove image blur.

The selective disruption of spatial working memory by eye movements

PubMed Central

Postle, Bradley R.; Idzikowski, Christopher; Sala, Sergio Della; Logie, Robert H.; Baddeley, Alan D.

2005-01-01

In the late 1970s/early 1980s, Baddeley and colleagues conducted a series of experiments investigating the role of eye movements in visual working memory. Although only described briefly in a book (Baddeley, 1986), these studies have influenced a remarkable number of empirical and theoretical developments in fields ranging from experimental psychology to human neuropsychology to nonhuman primate electrophysiology. This paper presents, in full detail, three critical studies from this series, together with a recently performed study that includes a level of eye movement measurement and control that was not available for the older studies. Together, the results demonstrate several facts about the sensitivity of visuospatial working memory to eye movements. First, it is eye movement control, not movement per se, that produces the disruptive effects. Second, these effects are limited to working memory for locations, and do not generalize to visual working memory for shapes. Third, they can be isolated to the storage/maintenance components of working memory (e.g., to the delay period of the delayed-recognition task). These facts have important implications for models of visual working memory. PMID:16556561

Methodological Aspects of Cognitive Rehabilitation with Eye Movement Desensitization and Reprocessing (EMDR)

PubMed Central

Zarghi, Afsaneh; Zali, Alireza; Tehranidost, Mehdi

2013-01-01

A variety of nervous system components such as medulla, pons, midbrain, cerebellum, basal ganglia, parietal, frontal and occipital lobes have role in Eye Movement Desensitization and Reprocessing (EMDR) processes. The eye movement is done simultaneously for attracting client's attention to an external stimulus while concentrating on a certain internal subject. Eye movement guided by therapist is the most common attention stimulus. The role of eye movement has been documented previously in relation with cognitive processing mechanisms. A series of systemic experiments have shown that the eyes’ spontaneous movement is associated with emotional and cognitive changes and results in decreased excitement, flexibility in attention, memory processing, and enhanced semantic recalling. Eye movement also decreases the memory's image clarity and the accompanying excitement. By using EMDR, we can reach some parts of memory which were inaccessible before and also emotionally intolerable. Various researches emphasize on the effectiveness of EMDR in treating and curing phobias, pains, and dependent personality disorders. Consequently, due to the involvement of multiple neural system components, this palliative method of treatment can also help to rehabilitate the neuro-cognitive system. PMID:25337334

Eying the future: Eye movement in past and future thinking.

PubMed

El Haj, Mohamad; Lenoble, Quentin

2017-06-07

We investigated eye movement during past and future thinking. Participants were invited to retrieve past events and to imagine future events while their scan path was recorded by an eye-tracker. Past thinking triggered more fixation (p < .05), and saccade counts (p < .05) than future thinking. Past and future thinking triggered a similar duration of fixations and saccades, as well as a similar amplitude of saccades. Interestingly, participants rated past thinking as more vivid than future thinking (p < .01). Therefore, the vividness of past thinking seems to be accompanied by an increased number of fixations and saccades. Fixations and saccades in past thinking can be interpreted as an attempt by the visual system to find (through saccades) and activate (through fixations) stored memory representations. The same interpretation can be applied to future thinking as this ability requires activation of past experiences. However, future thinking triggers fewer fixations and saccades than past thinking: this may be due to its decreased demand on visual imagery, but could also be related to a potentially deleterious effect of eye movements on spatial imagery required for future thinking. Copyright © 2017 Elsevier Ltd. All rights reserved.

Memory reactivation during rapid eye movement sleep promotes its generalization and integration in cortical stores.

PubMed

Sterpenich, Virginie; Schmidt, Christina; Albouy, Geneviève; Matarazzo, Luca; Vanhaudenhuyse, Audrey; Boveroux, Pierre; Degueldre, Christian; Leclercq, Yves; Balteau, Evelyne; Collette, Fabienne; Luxen, André; Phillips, Christophe; Maquet, Pierre

2014-06-01

Memory reactivation appears to be a fundamental process in memory consolidation. In this study we tested the influence of memory reactivation during rapid eye movement (REM) sleep on memory performance and brain responses at retrieval in healthy human participants. Fifty-six healthy subjects (28 women and 28 men, age [mean ± standard deviation]: 21.6 ± 2.2 y) participated in this functional magnetic resonance imaging (fMRI) study. Auditory cues were associated with pictures of faces during their encoding. These memory cues delivered during REM sleep enhanced subsequent accurate recollections but also false recognitions. These results suggest that reactivated memories interacted with semantically related representations, and induced new creative associations, which subsequently reduced the distinction between new and previously encoded exemplars. Cues had no effect if presented during stage 2 sleep, or if they were not associated with faces during encoding. Functional magnetic resonance imaging revealed that following exposure to conditioned cues during REM sleep, responses to faces during retrieval were enhanced both in a visual area and in a cortical region of multisensory (auditory-visual) convergence. These results show that reactivating memories during REM sleep enhances cortical responses during retrieval, suggesting the integration of recent memories within cortical circuits, favoring the generalization and schematization of the information.

Clinical Manifestation of Parkinson's Disease in Association with Rapid Eye Movement Sleep Behavior Disorder Onset.

PubMed

Zhang, Hui; Gu, Zhuqin; Sun, Liang; Cao, Ming; Li, Dawei; Ma, Jinghong; Chan, Piu

2016-01-01

To confirm whether the presence and/or timing of rapid eye movement sleep behavior disorder (RBD) onset were associated with differences in clinical features of Parkinson's disease (PD), clinical characteristics of PD patients with RBD occurring before and after PD diagnosis were investigated. Consecutive PD patients were enrolled between July 2011 and February 2012. RBD questionnaire Hong Kong and clinical interviews were used to identify RBD symptoms and onsets. All patients underwent evaluations to collect clinical and treatment information. Of all 79 PD patients, 21 (26.6%) and 22 (27.8%) patients had RBD prior to (RBD-PD) and after PD diagnosis (PD-RBD), respectively. Thirty-six (45.6%) PD patients reported no RBD at the time of study (PD-NRBD). PD-RBD had similar clinical features as PD-NRBD did except that Epworth sleepiness scale score was significantly higher in PD-RBD (p = 0.04). Compared to PD-RBD and PD-NRBD, RBD-PD had a higher frequency of reporting excessive daytime sleepiness (p = 0.019, p = 0.008, respectively) and constipation (p = 0.046, p = 0.032, respectively). Our preliminary results suggest that RBD-PD might be clinically different from PD-RBD, which appears to share similar characteristics with PD-NRBD, regarding only non-motor functions. © 2016 S. Karger AG, Basel.

A novel non-rapid-eye movement and rapid-eye-movement parasomnia with sleep breathing disorder associated with antibodies to IgLON5: a case series, characterisation of the antigen, and post-mortem study.

PubMed

Sabater, Lidia; Gaig, Carles; Gelpi, Ellen; Bataller, Luis; Lewerenz, Jan; Torres-Vega, Estefanía; Contreras, Angeles; Giometto, Bruno; Compta, Yaroslau; Embid, Cristina; Vilaseca, Isabel; Iranzo, Alex; Santamaría, Joan; Dalmau, Josep; Graus, Francesc

2014-06-01

Autoimmunity might be associated with or implicated in sleep and neurodegenerative disorders. We aimed to describe the features of a novel neurological syndrome associated with prominent sleep dysfunction and antibodies to a neuronal antigen. In this observational study, we used clinical and video polysomnography to identify a novel sleep disorder in three patients referred to the Sleep Unit of Hospital Clinic, University of Barcelona, Spain, for abnormal sleep behaviours and obstructive sleep apnoea. These patients had antibodies against a neuronal surface antigen, which were also present in five additional patients referred to our laboratory for antibody studies. These five patients had been assessed with polysomnography, which was done in our sleep unit in one patient and the recording reviewed in a second patient. Two patients underwent post-mortem brain examination. Immunoprecipitation and mass spectrometry were used to characterise the antigen and develop an assay for antibody testing. Serum or CSF from 298 patients with neurodegenerative, sleep, or autoimmune disorders served as control samples. All eight patients (five women; median age at disease onset 59 years [range 52-76]) had abnormal sleep movements and behaviours and obstructive sleep apnoea, as confirmed by polysomnography. Six patients had chronic progression with a median duration from symptom onset to death or last visit of 5 years (range 2-12); in four the sleep disorder was the initial and most prominent feature, and in two it was preceded by gait instability followed by dysarthria, dysphagia, ataxia, or chorea. Two patients had a rapid progression with disequilibrium, dysarthria, dysphagia, and central hypoventilation, and died 2 months and 6 months, respectively, after symptom onset. In five of five patients, video polysomnography showed features of obstructive sleep apnoea, stridor, and abnormal sleep architecture (undifferentiated non-rapid-eye-movement [non-REM] sleep or poorly structured

Smooth-pursuit eye-movement-related neuronal activity in macaque nucleus reticularis tegmenti pontis.

PubMed

Suzuki, David A; Yamada, Tetsuto; Yee, Robert D

2003-04-01

Neuronal responses that were observed during smooth-pursuit eye movements were recorded from cells in rostral portions of the nucleus reticularis tegmenti pontis (rNRTP). The responses were categorized as smooth-pursuit eye velocity (78%) or eye acceleration (22%). A separate population of rNRTP cells encoded static eye position. The sensitivity to pursuit eye velocity averaged 0.81 spikes/s per degrees /s, whereas the average sensitivity to pursuit eye acceleration was 0.20 spikes/s per degrees /s(2). Of the eye-velocity cells with horizontal preferences for pursuit responses, 56% were optimally responsive to contraversive smooth-pursuit eye movements and 44% preferred ipsiversive pursuit. For cells with vertical pursuit preferences, 61% preferred upward pursuit and 39% preferred downward pursuit. The direction selectivity was broad with 50% of the maximal response amplitude observed for directions of smooth pursuit up to +/-85 degrees away from the optimal direction. The activities of some rNRTP cells were linearly related to eye position with an average sensitivity of 2.1 spikes/s per deg. In some cells, the magnitude of the response during smooth-pursuit eye movements was affected by the position of the eyes even though these cells did not encode eye position. On average, pursuit centered to one side of screen center elicited a response that was 73% of the response amplitude obtained with tracking centered at screen center. For pursuit centered on the opposite side, the average response was 127% of the response obtained at screen center. The results provide a neuronal rationale for the slow, pursuit-like eye movements evoked with rNRTP microstimulation and for the deficits in smooth-pursuit eye movements observed with ibotenic acid injection into rNRTP. More globally, the results support the notion of a frontal and supplementary eye field-rNRTP-cerebellum pathway involved with controlling smooth-pursuit eye movements.

Effects of aging on eye movements in the real world

PubMed Central

Dowiasch, Stefan; Marx, Svenja; Einhäuser, Wolfgang; Bremmer, Frank

2015-01-01

The effects of aging on eye movements are well studied in the laboratory. Increased saccade latencies or decreased smooth-pursuit gain are well established findings. The question remains whether these findings are influenced by the rather untypical environment of a laboratory; that is, whether or not they transfer to the real world. We measured 34 healthy participants between the age of 25 and 85 during two everyday tasks in the real world: (I) walking down a hallway with free gaze, (II) visual tracking of an earth-fixed object while walking straight-ahead. Eye movements were recorded with a mobile light-weight eye tracker, the EyeSeeCam (ESC). We find that age significantly influences saccade parameters. With increasing age, saccade frequency, amplitude, peak velocity, and mean velocity are reduced and the velocity/amplitude distribution as well as the velocity profile become less skewed. In contrast to laboratory results on smooth pursuit, we did not find a significant effect of age on tracking eye-movements in the real world. Taken together, age-related eye-movement changes as measured in the laboratory only partly resemble those in the real world. It is well-conceivable that in the real world additional sensory cues, such as head-movement or vestibular signals, may partially compensate for age-related effects, which, according to this view, would be specific to early motion processing. In any case, our results highlight the importance of validity for natural situations when studying the impact of aging on real-life performance. PMID:25713524

Effects of aging on eye movements in the real world.

PubMed

Dowiasch, Stefan; Marx, Svenja; Einhäuser, Wolfgang; Bremmer, Frank

2015-01-01

The effects of aging on eye movements are well studied in the laboratory. Increased saccade latencies or decreased smooth-pursuit gain are well established findings. The question remains whether these findings are influenced by the rather untypical environment of a laboratory; that is, whether or not they transfer to the real world. We measured 34 healthy participants between the age of 25 and 85 during two everyday tasks in the real world: (I) walking down a hallway with free gaze, (II) visual tracking of an earth-fixed object while walking straight-ahead. Eye movements were recorded with a mobile light-weight eye tracker, the EyeSeeCam (ESC). We find that age significantly influences saccade parameters. With increasing age, saccade frequency, amplitude, peak velocity, and mean velocity are reduced and the velocity/amplitude distribution as well as the velocity profile become less skewed. In contrast to laboratory results on smooth pursuit, we did not find a significant effect of age on tracking eye-movements in the real world. Taken together, age-related eye-movement changes as measured in the laboratory only partly resemble those in the real world. It is well-conceivable that in the real world additional sensory cues, such as head-movement or vestibular signals, may partially compensate for age-related effects, which, according to this view, would be specific to early motion processing. In any case, our results highlight the importance of validity for natural situations when studying the impact of aging on real-life performance.

Chronic escitalopram treatment attenuated the accelerated rapid eye movement sleep transitions after selective rapid eye movement sleep deprivation: a model-based analysis using Markov chains.

PubMed

Kostyalik, Diána; Vas, Szilvia; Kátai, Zita; Kitka, Tamás; Gyertyán, István; Bagdy, Gyorgy; Tóthfalusi, László

2014-11-19

Shortened rapid eye movement (REM) sleep latency and increased REM sleep amount are presumed biological markers of depression. These sleep alterations are also observable in several animal models of depression as well as during the rebound sleep after selective REM sleep deprivation (RD). Furthermore, REM sleep fragmentation is typically associated with stress procedures and anxiety. The selective serotonin reuptake inhibitor (SSRI) antidepressants reduce REM sleep time and increase REM latency after acute dosing in normal condition and even during REM rebound following RD. However, their therapeutic outcome evolves only after weeks of treatment, and the effects of chronic treatment in REM-deprived animals have not been studied yet. Chronic escitalopram- (10 mg/kg/day, osmotic minipump for 24 days) or vehicle-treated rats were subjected to a 3-day-long RD on day 21 using the flower pot procedure or kept in home cage. On day 24, fronto-parietal electroencephalogram, electromyogram and motility were recorded in the first 2 h of the passive phase. The observed sleep patterns were characterized applying standard sleep metrics, by modelling the transitions between sleep phases using Markov chains and by spectral analysis. Based on Markov chain analysis, chronic escitalopram treatment attenuated the REM sleep fragmentation [accelerated transition rates between REM and non-REM (NREM) stages, decreased REM sleep residence time between two transitions] during the rebound sleep. Additionally, the antidepressant avoided the frequent awakenings during the first 30 min of recovery period. The spectral analysis showed that the SSRI prevented the RD-caused elevation in theta (5-9 Hz) power during slow-wave sleep. Conversely, based on the aggregate sleep metrics, escitalopram had only moderate effects and it did not significantly attenuate the REM rebound after RD. In conclusion, chronic SSRI treatment is capable of reducing several effects on sleep which might be the consequence

MR-eyetracker: a new method for eye movement recording in functional magnetic resonance imaging.

PubMed

Kimmig, H; Greenlee, M W; Huethe, F; Mergner, T

1999-06-01

We present a method for recording saccadic and pursuit eye movements in the magnetic resonance tomograph designed for visual functional magnetic resonance imaging (fMRI) experiments. To reliably classify brain areas as pursuit or saccade related it is important to carefully measure the actual eye movements. For this purpose, infrared light, created outside the scanner by light-emitting diodes (LEDs), is guided via optic fibers into the head coil and onto the eye of the subject. Two additional fiber optical cables pick up the light reflected by the iris. The illuminating and detecting cables are mounted in a plastic eyepiece that is manually lowered to the level of the eye. By means of differential amplification, we obtain a signal that covaries with the horizontal position of the eye. Calibration of eye position within the scanner yields an estimate of eye position with a resolution of 0.2 degrees at a sampling rate of 1000 Hz. Experiments are presented that employ echoplanar imaging with 12 image planes through visual, parietal and frontal cortex while subjects performed saccadic and pursuit eye movements. The distribution of BOLD (blood oxygen level dependent) responses is shown to depend on the type of eye movement performed. Our method yields high temporal and spatial resolution of the horizontal component of eye movements during fMRI scanning. Since the signal is purely optical, there is no interaction between the eye movement signals and the echoplanar images. This reasonably priced eye tracker can be used to control eye position and monitor eye movements during fMRI.

Eye Movement Control during Reading: I. The Location of Initial Eye Fixations on Words. Technical Report No. 406.

ERIC Educational Resources Information Center

McConkie, G. W.; And Others

Sixty-six college students read two chapters from a contemporary novel while their eye movements were monitored. The eye movement data were analyzed to identify factors that influence the location of a reader's initial eye fixation on a word. When the data were partitioned according to the location of the prior fixation (i.e., launch site), the…

Geometric adjustments to account for eye eccentricity in processing horizontal and vertical eye and head movement data

NASA Technical Reports Server (NTRS)

Huebner, W. P.; Paloski, W. H.; Reschke, M. F.; Bloomberg, J. J.

1995-01-01

Neglecting the eccentric position of the eyes in the head can lead to erroneous interpretation of ocular motor data, particularly for near targets. We discuss the geometric effects that eye eccentricity has on the processing of target-directed eye and head movement data, and we highlight two approaches to processing and interpreting such data. The first approach involves determining the true position of the target with respect to the location of the eyes in space for evaluating the efficacy of gaze, and it allows calculation of retinal error directly from measured eye, head, and target data. The second approach effectively eliminates eye eccentricity effects by adjusting measured eye movement data to yield equivalent responses relative to a specified reference location (such as the center of head rotation). This latter technique can be used to standardize measured eye movement signals, enabling waveforms collected under different experimental conditions to be directly compared, both with the measured target signals and with each other. Mathematical relationships describing these approaches are presented for horizontal and vertical rotations, for both tangential and circumferential display screens, and efforts are made to describe the sensitivity of parameter variations on the calculated results.

Efficacy of Eye Movement Desensitization in the treatment of cognitive intrusions related to a past stressful event.

PubMed

Lytle, Richard A; Hazlett-Stevens, Holly; Borkovec, T D

2002-01-01

Much of the Eye Movement Desensitization and Reprocessing (EMDR) efficacy research has been widely criticized, limiting scientific understanding of its therapeutic components. The present investigation of Eye Movement Desensitization (EMD) effectiveness included undergraduate students reporting current intrusive cognitions conceming a traumatic event. Forty-five participants received a single treatment session of either: (a) EMD, as described by Shapiro [J. Behav. Ther. Exp. Psychiatry 20 (1989b) 211], (b) an identical procedure which employed eye fixation on a stationary target, or (c) non-directive counseling. Standardized self-report, subjective rating, Daily Diary, and intrusive thought sampling measures were collected before and after treatment. Results indicated that participants in the eye fixation group reported marginally (p < .052) fewer cognitive intrusions than the non-directive group 1 week following treatment. No significant differences between the EMD and non-directive conditions or between the EMD and eye fixation conditions on this measure were found. During the treatment session, both desensitization groups were superior to the non-directive group in reducing reported vividness of the mental image of the original event. However, the non-directive group improved to the level of the two other groups by the following week. Rapid saccadic eye movements were therefore unrelated to immediate treatment effects for this sub-clinical sample, and non-directive treatment largely yielded eventual outcomes equivalent to the two desensitization conditions.

Classification of visual and linguistic tasks using eye-movement features.

PubMed

Coco, Moreno I; Keller, Frank

2014-03-07

The role of the task has received special attention in visual-cognition research because it can provide causal explanations of goal-directed eye-movement responses. The dependency between visual attention and task suggests that eye movements can be used to classify the task being performed. A recent study by Greene, Liu, and Wolfe (2012), however, fails to achieve accurate classification of visual tasks based on eye-movement features. In the present study, we hypothesize that tasks can be successfully classified when they differ with respect to the involvement of other cognitive domains, such as language processing. We extract the eye-movement features used by Greene et al. as well as additional features from the data of three different tasks: visual search, object naming, and scene description. First, we demonstrated that eye-movement responses make it possible to characterize the goals of these tasks. Then, we trained three different types of classifiers and predicted the task participants performed with an accuracy well above chance (a maximum of 88% for visual search). An analysis of the relative importance of features for classification accuracy reveals that just one feature, i.e., initiation time, is sufficient for above-chance performance (a maximum of 79% accuracy in object naming). Crucially, this feature is independent of task duration, which differs systematically across the three tasks we investigated. Overall, the best task classification performance was obtained with a set of seven features that included both spatial information (e.g., entropy of attention allocation) and temporal components (e.g., total fixation on objects) of the eye-movement record. This result confirms the task-dependent allocation of visual attention and extends previous work by showing that task classification is possible when tasks differ in the cognitive processes involved (purely visual tasks such as search vs. communicative tasks such as scene description).

Biometric recognition via texture features of eye movement trajectories in a visual searching task.

PubMed

Li, Chunyong; Xue, Jiguo; Quan, Cheng; Yue, Jingwei; Zhang, Chenggang

2018-01-01

Biometric recognition technology based on eye-movement dynamics has been in development for more than ten years. Different visual tasks, feature extraction and feature recognition methods are proposed to improve the performance of eye movement biometric system. However, the correct identification and verification rates, especially in long-term experiments, as well as the effects of visual tasks and eye trackers' temporal and spatial resolution are still the foremost considerations in eye movement biometrics. With a focus on these issues, we proposed a new visual searching task for eye movement data collection and a new class of eye movement features for biometric recognition. In order to demonstrate the improvement of this visual searching task being used in eye movement biometrics, three other eye movement feature extraction methods were also tested on our eye movement datasets. Compared with the original results, all three methods yielded better results as expected. In addition, the biometric performance of these four feature extraction methods was also compared using the equal error rate (EER) and Rank-1 identification rate (Rank-1 IR), and the texture features introduced in this paper were ultimately shown to offer some advantages with regard to long-term stability and robustness over time and spatial precision. Finally, the results of different combinations of these methods with a score-level fusion method indicated that multi-biometric methods perform better in most cases.

Biometric recognition via texture features of eye movement trajectories in a visual searching task

PubMed Central

Li, Chunyong; Xue, Jiguo; Quan, Cheng; Yue, Jingwei

2018-01-01

Biometric recognition technology based on eye-movement dynamics has been in development for more than ten years. Different visual tasks, feature extraction and feature recognition methods are proposed to improve the performance of eye movement biometric system. However, the correct identification and verification rates, especially in long-term experiments, as well as the effects of visual tasks and eye trackers’ temporal and spatial resolution are still the foremost considerations in eye movement biometrics. With a focus on these issues, we proposed a new visual searching task for eye movement data collection and a new class of eye movement features for biometric recognition. In order to demonstrate the improvement of this visual searching task being used in eye movement biometrics, three other eye movement feature extraction methods were also tested on our eye movement datasets. Compared with the original results, all three methods yielded better results as expected. In addition, the biometric performance of these four feature extraction methods was also compared using the equal error rate (EER) and Rank-1 identification rate (Rank-1 IR), and the texture features introduced in this paper were ultimately shown to offer some advantages with regard to long-term stability and robustness over time and spatial precision. Finally, the results of different combinations of these methods with a score-level fusion method indicated that multi-biometric methods perform better in most cases. PMID:29617383

The Clinical Phenotype of Idiopathic Rapid Eye Movement Sleep Behavior Disorder at Presentation: A Study in 203 Consecutive Patients

PubMed Central

Fernández-Arcos, Ana; Iranzo, Alex; Serradell, Mónica; Gaig, Carles; Santamaria, Joan

2016-01-01

Objective: To describe the clinical phenotype of idiopathic rapid eye movement (REM) sleep behavior disorder (IRBD) at presentation in a sleep center. Methods: Clinical history review of 203 consecutive patients with IRBD identified between 1990 and 2014. IRBD was diagnosed by clinical history plus video-polysomnographic demonstration of REM sleep with increased electromyographic activity linked to abnormal behaviors. Results: Patients were 80% men with median age at IRBD diagnosis of 68 y (range, 50–85 y). In addition to the already known clinical picture of IRBD, other important features were apparent: 44% of the patients were not aware of their dream-enactment behaviors and 70% reported good sleep quality. In most of these cases bed partners were essential to convince patients to seek medical help. In 11% IRBD was elicited only after specific questioning when patients consulted for other reasons. Seven percent did not recall unpleasant dreams. Leaving the bed occurred occasionally in 24% of subjects in whom dementia with Lewy bodies often developed eventually. For the correct diagnosis of IRBD, video-polysomnography had to be repeated in 16% because of insufficient REM sleep or electromyographic artifacts from coexistent apneas. Some subjects with comorbid obstructive sleep apnea reported partial improvement of RBD symptoms following continuous positive airway pressure therapy. Lack of therapy with clonazepam resulted in an increased risk of sleep related injuries. Synucleinopathy was frequently diagnosed, even in patients with mild severity or uncommon IRBD presentations (e.g., patients who reported sleeping well, onset triggered by a life event, nocturnal ambulation) indicating that the development of a neurodegenerative disease is independent of the clinical presentation of IRBD. Conclusions: We report the largest IRBD cohort observed in a single center to date and highlight frequent features that were not reported or not sufficiently emphasized in previous

Eye movements during visual search in patients with glaucoma

PubMed Central

2012-01-01

Background Glaucoma has been shown to lead to disability in many daily tasks including visual search. This study aims to determine whether the saccadic eye movements of people with glaucoma differ from those of people with normal vision, and to investigate the association between eye movements and impaired visual search. Methods Forty patients (mean age: 67 [SD: 9] years) with a range of glaucomatous visual field (VF) defects in both eyes (mean best eye mean deviation [MD]: –5.9 (SD: 5.4) dB) and 40 age-related people with normal vision (mean age: 66 [SD: 10] years) were timed as they searched for a series of target objects in computer displayed photographs of real world scenes. Eye movements were simultaneously recorded using an eye tracker. Average number of saccades per second, average saccade amplitude and average search duration across trials were recorded. These response variables were compared with measurements of VF and contrast sensitivity. Results The average rate of saccades made by the patient group was significantly smaller than the number made by controls during the visual search task (P = 0.02; mean reduction of 5.6% (95% CI: 0.1 to 10.4%). There was no difference in average saccade amplitude between the patients and the controls (P = 0.09). Average number of saccades was weakly correlated with aspects of visual function, with patients with worse contrast sensitivity (PR logCS; Spearman’s rho: 0.42; P = 0.006) and more severe VF defects (best eye MD; Spearman’s rho: 0.34; P = 0.037) tending to make less eye movements during the task. Average detection time in the search task was associated with the average rate of saccades in the patient group (Spearman’s rho = −0.65; P < 0.001) but this was not apparent in the controls. Conclusions The average rate of saccades made during visual search by this group of patients was fewer than those made by people with normal vision of a similar average age. There was wide

Driving experience and special skills reflected in eye movements

NASA Astrophysics Data System (ADS)

Paeglis, Roberts; Bluss, Kristaps; Atvars, Aigars

2011-10-01

When driving a vehicle, people use the central vision both to plan ahead and monitor their performance feedback (research by Donges, 1978 [1], and after). Discussion is ongoing if making eye movements do more than gathering information. Moving eyes may also prepare the following body movements like steering. Different paradigms exist to explore vision in driving. Our perspective was to quantify eye movements and fixation patterns of different proficiency individuals, a driving learner, a novice, an experienced driver and a European level car racer. Thus for safety reasons we started by asking them to follow a video tour through a known city, remote from an infrared eye tracker sampling at 250 Hz. We report that gaze strategy of an experienced driver differs qualitatively from that of an automobile sports master. Quantitative differences only were found between the latter and a driving learner or a novice driver. Experience in a motor action provides skills different from sports training. We are aiming at testing this finding in real world driving.

Dynamic modulation of ocular orientation during visually guided saccades and smooth-pursuit eye movements

NASA Technical Reports Server (NTRS)

Hess, Bernhard J M.; Angelaki, Dora E.

2003-01-01

Rotational disturbances of the head about an off-vertical yaw axis induce a complex vestibuloocular reflex pattern that reflects the brain's estimate of head angular velocity as well as its estimate of instantaneous head orientation (at a reduced scale) in space coordinates. We show that semicircular canal and otolith inputs modulate torsional and, to a certain extent, also vertical ocular orientation of visually guided saccades and smooth-pursuit eye movements in a similar manner as during off-vertical axis rotations in complete darkness. It is suggested that this graviceptive control of eye orientation facilitates rapid visual spatial orientation during motion.

Eye Movements during Multiple Object Tracking: Where Do Participants Look?

ERIC Educational Resources Information Center

Fehd, Hilda M.; Seiffert, Adriane E.

2008-01-01

Similar to the eye movements you might make when viewing a sports game, this experiment investigated where participants tend to look while keeping track of multiple objects. While eye movements were recorded, participants tracked either 1 or 3 of 8 red dots that moved randomly within a square box on a black background. Results indicated that…

Initial Scene Representations Facilitate Eye Movement Guidance in Visual Search

ERIC Educational Resources Information Center

Castelhano, Monica S.; Henderson, John M.

2007-01-01

What role does the initial glimpse of a scene play in subsequent eye movement guidance? In 4 experiments, a brief scene preview was followed by object search through the scene via a small moving window that was tied to fixation position. Experiment 1 demonstrated that the scene preview resulted in more efficient eye movements compared with a…

Adaptive Acceleration of Visually Evoked Smooth Eye Movements in Mice

PubMed Central

2016-01-01

The optokinetic response (OKR) consists of smooth eye movements following global motion of the visual surround, which suppress image slip on the retina for visual acuity. The effective performance of the OKR is limited to rather slow and low-frequency visual stimuli, although it can be adaptably improved by cerebellum-dependent mechanisms. To better understand circuit mechanisms constraining OKR performance, we monitored how distinct kinematic features of the OKR change over the course of OKR adaptation, and found that eye acceleration at stimulus onset primarily limited OKR performance but could be dramatically potentiated by visual experience. Eye acceleration in the temporal-to-nasal direction depended more on the ipsilateral floccular complex of the cerebellum than did that in the nasal-to-temporal direction. Gaze-holding following the OKR was also modified in parallel with eye-acceleration potentiation. Optogenetic manipulation revealed that synchronous excitation and inhibition of floccular complex Purkinje cells could effectively accelerate eye movements in the nasotemporal and temporonasal directions, respectively. These results collectively delineate multiple motor pathways subserving distinct aspects of the OKR in mice and constrain hypotheses regarding cellular mechanisms of the cerebellum-dependent tuning of movement acceleration. SIGNIFICANCE STATEMENT Although visually evoked smooth eye movements, known as the optokinetic response (OKR), have been studied in various species for decades, circuit mechanisms of oculomotor control and adaptation remain elusive. In the present study, we assessed kinematics of the mouse OKR through the course of adaptation training. Our analyses revealed that eye acceleration at visual-stimulus onset primarily limited working velocity and frequency range of the OKR, yet could be dramatically potentiated during OKR adaptation. Potentiation of eye acceleration exhibited different properties between the nasotemporal and

Persistence in eye movement during visual search

NASA Astrophysics Data System (ADS)

Amor, Tatiana A.; Reis, Saulo D. S.; Campos, Daniel; Herrmann, Hans J.; Andrade, José S.

2016-02-01

As any cognitive task, visual search involves a number of underlying processes that cannot be directly observed and measured. In this way, the movement of the eyes certainly represents the most explicit and closest connection we can get to the inner mechanisms governing this cognitive activity. Here we show that the process of eye movement during visual search, consisting of sequences of fixations intercalated by saccades, exhibits distinctive persistent behaviors. Initially, by focusing on saccadic directions and intersaccadic angles, we disclose that the probability distributions of these measures show a clear preference of participants towards a reading-like mechanism (geometrical persistence), whose features and potential advantages for searching/foraging are discussed. We then perform a Multifractal Detrended Fluctuation Analysis (MF-DFA) over the time series of jump magnitudes in the eye trajectory and find that it exhibits a typical multifractal behavior arising from the sequential combination of saccades and fixations. By inspecting the time series composed of only fixational movements, our results reveal instead a monofractal behavior with a Hurst exponent , which indicates the presence of long-range power-law positive correlations (statistical persistence). We expect that our methodological approach can be adopted as a way to understand persistence and strategy-planning during visual search.

The Cerebellar Dysplasia of Chiari II Malformation as Revealed by Eye Movements

PubMed Central

Salman, Michael S.; Dennis, Maureen; Sharpe, James A.

2011-01-01

Introduction Chiari type II malformation (CII) is a developmental deformity of the hindbrain. We have previously reported that many patients with CII have impaired smooth pursuit, while few make inaccurate saccades or have an abnormal vestibulo-ocular reflex. In contrast, saccadic adaptation and visual fixation are normal. In this report, we correlate results from several eye movement studies with neuroimaging in CII. We present a model for structural changes within the cerebellum in CII. Methods Saccades, smooth pursuit, the vestibulo-ocular reflex, and visual fixation were recorded in 21 patients with CII, aged 8–19 years and 39 age-matched controls, using an infrared eye tracker. Qualitative and quantitative MRI data were correlated with eye movements in 19 CII patients and 28 controls. Results Nine patients with CII had abnormal eye movements. Smooth pursuit gain was subnormal in eight, saccadic accuracy abnormal in four, and vestibulo-ocular reflex gain abnormal in three. None had fixation instability. Patients with CII had a significantly smaller cerebellar volume than controls, and those with normal eye motion had an expanded midsagittal vermis compared to controls. However, patients with abnormal eye movements had a smaller (non-expanded) midsagittal vermis area, posterior fossa area and medial cerebellar volumes than CII patients with normal eye movements. Conclusions The deformity of CII affects the structure and function of the cerebellum selectively and differently in those with abnormal eye movements. We propose that the vermis can expand when compressed within a small posterior fossa in some CII patients, thus sparing its ocular motor functions. PMID:19960749

Anticipatory smooth eye movements with random-dot kinematograms

PubMed Central

Santos, Elio M.; Gnang, Edinah K.; Kowler, Eileen

2012-01-01

Anticipatory smooth eye movements were studied in response to expectations of motion of random-dot kinematograms (RDKs). Dot lifetime was limited (52–208 ms) to prevent selection and tracking of the motion of local elements and to disrupt the perception of an object moving across space. Anticipatory smooth eye movements were found in response to cues signaling the future direction of global RDK motion, either prior to the onset of the RDK or prior to a change in its direction of motion. Cues signaling the lifetime of the dots were not effective. These results show that anticipatory smooth eye movements can be produced by expectations of global motion and do not require a sustained representation of an object or set of objects moving across space. At the same time, certain properties of global motion (direction) were more sensitive to cues than others (dot lifetime), suggesting that the rules by which prediction operates to influence pursuit may go beyond simple associations between cues and the upcoming motion of targets. PMID:23027686

The control of voluntary eye movements: new perspectives.

PubMed

Krauzlis, Richard J

2005-04-01

Primates use two types of voluntary eye movements to track objects of interest: pursuit and saccades. Traditionally, these two eye movements have been viewed as distinct systems that are driven automatically by low-level visual inputs. However, two sets of findings argue for a new perspective on the control of voluntary eye movements. First, recent experiments have shown that pursuit and saccades are not controlled by entirely different neural pathways but are controlled by similar networks of cortical and subcortical regions and, in some cases, by the same neurons. Second, pursuit and saccades are not automatic responses to retinal inputs but are regulated by a process of target selection that involves a basic form of decision making. The selection process itself is guided by a variety of complex processes, including attention, perception, memory, and expectation. Together, these findings indicate that pursuit and saccades share a similar functional architecture. These points of similarity may hold the key for understanding how neural circuits negotiate the links between the many higher order functions that can influence behavior and the singular and coordinated motor actions that follow.

Eye movements during object recognition in visual agnosia.

PubMed

Charles Leek, E; Patterson, Candy; Paul, Matthew A; Rafal, Robert; Cristino, Filipe

2012-07-01

This paper reports the first ever detailed study about eye movement patterns during single object recognition in visual agnosia. Eye movements were recorded in a patient with an integrative agnosic deficit during two recognition tasks: common object naming and novel object recognition memory. The patient showed normal directional biases in saccades and fixation dwell times in both tasks and was as likely as controls to fixate within object bounding contour regardless of recognition accuracy. In contrast, following initial saccades of similar amplitude to controls, the patient showed a bias for short saccades. In object naming, but not in recognition memory, the similarity of the spatial distributions of patient and control fixations was modulated by recognition accuracy. The study provides new evidence about how eye movements can be used to elucidate the functional impairments underlying object recognition deficits. We argue that the results reflect a breakdown in normal functional processes involved in the integration of shape information across object structure during the visual perception of shape. Copyright © 2012 Elsevier Ltd. All rights reserved.

Language-driven anticipatory eye movements in virtual reality.

PubMed

Eichert, Nicole; Peeters, David; Hagoort, Peter

2018-06-01

Predictive language processing is often studied by measuring eye movements as participants look at objects on a computer screen while they listen to spoken sentences. This variant of the visual-world paradigm has revealed that information encountered by a listener at a spoken verb can give rise to anticipatory eye movements to a target object, which is taken to indicate that people predict upcoming words. The ecological validity of such findings remains questionable, however, because these computer experiments used two-dimensional stimuli that were mere abstractions of real-world objects. Here we present a visual-world paradigm study in a three-dimensional (3-D) immersive virtual reality environment. Despite significant changes in the stimulus materials and the different mode of stimulus presentation, language-mediated anticipatory eye movements were still observed. These findings thus indicate that people do predict upcoming words during language comprehension in a more naturalistic setting where natural depth cues are preserved. Moreover, the results confirm the feasibility of using eyetracking in rich and multimodal 3-D virtual environments.

Saccadic eye movement during spaceflight

NASA Technical Reports Server (NTRS)

Uri, John J.; Linder, Barry J.; Moore, Thomas P.; Pool, Sam L.; Thornton, William E.

1989-01-01

Saccadic eye movements were studied in six subjects during two Space Shuttle missions. Reaction time, peak velocity and accuracy of horizontal, visually-guided saccades were examined preflight, inflight and postflight. Conventional electro-oculography was used to record eye position, with the subjects responding to pseudo-randomly illuminated targets at 0 deg and + or - 10 deg and 20 deg visual angles. In all subjects, preflight measurements were within normal limits. Reaction time was significantly increased inflight, while peak velocity was significantly decreased. A tendency toward a greater proportion of hypometric saccades inflight was also noted. Possible explanations for these changes and possible correlations with space motion sickness are discussed.

Chess players' eye movements reveal rapid recognition of complex visual patterns: Evidence from a chess-related visual search task.

PubMed

Sheridan, Heather; Reingold, Eyal M

2017-03-01

To explore the perceptual component of chess expertise, we monitored the eye movements of expert and novice chess players during a chess-related visual search task that tested anecdotal reports that a key differentiator of chess skill is the ability to visualize the complex moves of the knight piece. Specifically, chess players viewed an array of four minimized chessboards, and they rapidly searched for the target board that allowed a knight piece to reach a target square in three moves. On each trial, there was only one target board (i.e., the "Yes" board), and for the remaining "lure" boards, the knight's path was blocked on either the first move (the "Easy No" board) or the second move (i.e., "the Difficult No" board). As evidence that chess experts can rapidly differentiate complex chess-related visual patterns, the experts (but not the novices) showed longer first-fixation durations on the "Yes" board relative to the "Difficult No" board. Moreover, as hypothesized, the task strongly differentiated chess skill: Reaction times were more than four times faster for the experts relative to novices, and reaction times were correlated with within-group measures of expertise (i.e., official chess ratings, number of hours of practice). These results indicate that a key component of chess expertise is the ability to rapidly recognize complex visual patterns.

Cat and mouse search: the influence of scene and object analysis on eye movements when targets change locations during search.

PubMed

Hillstrom, Anne P; Segabinazi, Joice D; Godwin, Hayward J; Liversedge, Simon P; Benson, Valerie

2017-02-19

We explored the influence of early scene analysis and visible object characteristics on eye movements when searching for objects in photographs of scenes. On each trial, participants were shown sequentially either a scene preview or a uniform grey screen (250 ms), a visual mask, the name of the target and the scene, now including the target at a likely location. During the participant's first saccade during search, the target location was changed to: (i) a different likely location, (ii) an unlikely but possible location or (iii) a very implausible location. The results showed that the first saccade landed more often on the likely location in which the target re-appeared than on unlikely or implausible locations, and overall the first saccade landed nearer the first target location with a preview than without. Hence, rapid scene analysis influenced initial eye movement planning, but availability of the target rapidly modified that plan. After the target moved, it was found more quickly when it appeared in a likely location than when it appeared in an unlikely or implausible location. The findings show that both scene gist and object properties are extracted rapidly, and are used in conjunction to guide saccadic eye movements during visual search.This article is part of the themed issue 'Auditory and visual scene analysis'. © 2017 The Author(s).

Zinc-containing yeast extract promotes nonrapid eye movement sleep in mice.

PubMed

Cherasse, Yoan; Saito, Hitomi; Nagata, Nanae; Aritake, Kosuke; Lazarus, Michael; Urade, Yoshihiro

2015-10-01

Zinc is an essential trace element for humans and animals, being located, among other places, in the synaptic vesicles of cortical glutamatergic neurons and hippocampal mossy fibers in the brain. Extracellular zinc has the potential to interact with and modulate many different synaptic targets, including glutamate and GABA receptors. Because of the central role of these neurotransmitters in brain activity, we examined in this study the sleep-promoting activity of zinc by monitoring locomotor activity and electroencephalogram after its administration to mice. Zinc-containing yeast extract (40 and 80 mg/kg) dose dependently increased the total amount of nonrapid eye movement sleep and decreased the locomotor activity. However, this preparation did not change the amount of rapid eye movement sleep or show any adverse effects such as rebound of insomnia during a period of 24 h following the induction of sleep; whereas the extracts containing other divalent cations (manganese, iron, and copper) did not decrease the locomotor activity. This is the first evidence that zinc can induce sleep. Our data open the way to new types of food supplements designed to improve sleep. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Automated analysis of connected speech reveals early biomarkers of Parkinson's disease in patients with rapid eye movement sleep behaviour disorder.

PubMed

Hlavnička, Jan; Čmejla, Roman; Tykalová, Tereza; Šonka, Karel; Růžička, Evžen; Rusz, Jan

2017-02-02

For generations, the evaluation of speech abnormalities in neurodegenerative disorders such as Parkinson's disease (PD) has been limited to perceptual tests or user-controlled laboratory analysis based upon rather small samples of human vocalizations. Our study introduces a fully automated method that yields significant features related to respiratory deficits, dysphonia, imprecise articulation and dysrhythmia from acoustic microphone data of natural connected speech for predicting early and distinctive patterns of neurodegeneration. We compared speech recordings of 50 subjects with rapid eye movement sleep behaviour disorder (RBD), 30 newly diagnosed, untreated PD patients and 50 healthy controls, and showed that subliminal parkinsonian speech deficits can be reliably captured even in RBD patients, which are at high risk of developing PD or other synucleinopathies. Thus, automated vocal analysis should soon be able to contribute to screening and diagnostic procedures for prodromal parkinsonian neurodegeneration in natural environments.

Do patients with rapid eye movement sleep behavior disorder have a disease-specific personality?

PubMed

Sasai, Taeko; Inoue, Yuichi; Matsuura, Masato

2012-06-01

Rapid eye movement sleep behavior disorder (RBD) occurs idiopathically (iRBD), frequently representing a prodromal phase of Parkinson's disease (PD). Previous reports have described that patients with PD have premorbid personality profiles such as industriousness, inflexibility, cautiousness, and lack of novelty seeking. As well, psychological stress often aggravates RBD symptoms. These phenomena encouraged us to investigate personality profiles in iRBD patients. In this study, 53 patients with iRBD and 49 age and sex-matched healthy controls (HC) were enrolled. We used the revised version of the NEO Personality Inventory (NEO-PIR) to measure the personality of these subjects, and the 5 domains and the 30 facets of the NEO-PIR were compared between the two groups. Within the iRBD group, we investigated the association between RBD variables, e.g. the proportion of REM sleep without atonia (RWA/REM), length of RBD morbidity, frequency of vocalization or abnormal behavior, and the variables of NEO-PIR. In the patients, olfactory function was significantly lower than that of healthy controls, but the inventory differences were not significant. The inventory showed no association with any RBD variable, or the existence of aggravation of these symptoms triggered by psychological stress, or olfactory dysfunction. These results suggest that RBD patients do not have a personality profile that might predict PD development. The personality profile itself cannot explain the psychological-stress-dependent aggravation of RBD symptoms. Copyright © 2011 Elsevier Ltd. All rights reserved.

Rapid target foraging with reach or gaze: The hand looks further ahead than the eye

PubMed Central

2017-01-01

Real-world tasks typically consist of a series of target-directed actions and often require choices about which targets to act on and in what order. Such choice behavior can be assessed from an optimal foraging perspective whereby target selection is shaped by a balance between rewards and costs. Here we evaluated such decision-making in a rapid movement foraging task. On a given trial, participants were presented with 15 targets of varying size and value and were instructed to harvest as much reward as possible by either moving a handle to the targets (hand task) or by briefly fixating them (eye task). The short trial duration enabled participants to harvest about half the targets, ensuring that total reward was due to choice behavior. We developed a probabilistic model to predict target-by-target harvesting choices that considered the rewards and movement-related costs (i.e., target distance and size) associated with the current target as well as future targets. In the hand task, in comparison to the eye task, target choice was more strongly influenced by movement-related costs and took into account a greater number of future targets, consistent with the greater costs associated with arm movement. In both tasks, participants exhibited near-optimal behaviour and in a constrained version of the hand task in which choices could only be based on target positions, participants consistently chose among the shortest movement paths. Our results demonstrate that people can rapidly and effectively integrate values and movement-related costs associated with current and future targets when sequentially harvesting targets. PMID:28683138

One-Step "Change" and "Compare" Word Problems: Focusing on Eye-Movements

ERIC Educational Resources Information Center

Moutsios-Rentzos, Andreas; Stamatis, Panagiotis J.

2015-01-01

Introduction. In this study, we focus on the relationship between the students' mathematical thinking and their non-mechanically identified eye-movements with the purpose to gain deeper understanding about the students' reasoning processes and to investigate the feasibility of incorporating eye-movement information in everyday pedagogy. Method.…

Acting without seeing: Eye movements reveal visual processing without awareness Miriam Spering & Marisa Carrasco

PubMed Central

Spering, Miriam; Carrasco, Marisa

2015-01-01

Visual perception and eye movements are considered to be tightly linked. Diverse fields, ranging from developmental psychology to computer science, utilize eye tracking to measure visual perception. However, this prevailing view has been challenged by recent behavioral studies. We review converging evidence revealing dissociations between the contents of perceptual awareness and different types of eye movements. Such dissociations reveal situations in which eye movements are sensitive to particular visual features that fail to modulate perceptual reports. We also discuss neurophysiological, neuroimaging and clinical studies supporting the role of subcortical pathways for visual processing without awareness. Our review links awareness to perceptual-eye movement dissociations and furthers our understanding of the brain pathways underlying vision and movement with and without awareness. PMID:25765322

Fixational eye movement: a negligible source of dynamic aberration.

PubMed

Mecê, Pedro; Jarosz, Jessica; Conan, Jean-Marc; Petit, Cyril; Grieve, Kate; Paques, Michel; Meimon, Serge

2018-02-01

To evaluate the contribution of fixational eye movements to dynamic aberration, 50 healthy eyes were examined with an original custom-built Shack-Hartmann aberrometer, running at a temporal frequency of 236Hz, with 22 lenslets across a 5mm pupil, synchronized with a 236Hz pupil tracker. A comparison of the dynamic behavior of the first 21 Zernike modes (starting from defocus) with and without digital pupil stabilization, on a 3.4s sequence between blinks, showed that the contribution of fixational eye movements to dynamic aberration is negligible. Therefore we highlighted the fact that a pupil tracker coupled to an Adaptive Optics Ophthalmoscope is not essential to achieve diffraction-limited resolution.

Tracking without perceiving: a dissociation between eye movements and motion perception.

PubMed

Spering, Miriam; Pomplun, Marc; Carrasco, Marisa

2011-02-01

Can people react to objects in their visual field that they do not consciously perceive? We investigated how visual perception and motor action respond to moving objects whose visibility is reduced, and we found a dissociation between motion processing for perception and for action. We compared motion perception and eye movements evoked by two orthogonally drifting gratings, each presented separately to a different eye. The strength of each monocular grating was manipulated by inducing adaptation to one grating prior to the presentation of both gratings. Reflexive eye movements tracked the vector average of both gratings (pattern motion) even though perceptual responses followed one motion direction exclusively (component motion). Observers almost never perceived pattern motion. This dissociation implies the existence of visual-motion signals that guide eye movements in the absence of a corresponding conscious percept.

Disk space and load time requirements for eye movement biometric databases

NASA Astrophysics Data System (ADS)

Kasprowski, Pawel; Harezlak, Katarzyna

2016-06-01

Biometric identification is a very popular area of interest nowadays. Problems with the so-called physiological methods like fingerprints or iris recognition resulted in increased attention paid to methods measuring behavioral patterns. Eye movement based biometric (EMB) identification is one of the interesting behavioral methods and due to the intensive development of eye tracking devices it has become possible to define new methods for the eye movement signal processing. Such method should be supported by an efficient storage used to collect eye movement data and provide it for further analysis. The aim of the research was to check various setups enabling such a storage choice. There were various aspects taken into consideration, like disk space usage, time required for loading and saving whole data set or its chosen parts.

Eye movements reveal epistemic curiosity in human observers.

PubMed

Baranes, Adrien; Oudeyer, Pierre-Yves; Gottlieb, Jacqueline

2015-12-01

Saccadic (rapid) eye movements are primary means by which humans and non-human primates sample visual information. However, while saccadic decisions are intensively investigated in instrumental contexts where saccades guide subsequent actions, it is largely unknown how they may be influenced by curiosity - the intrinsic desire to learn. While saccades are sensitive to visual novelty and visual surprise, no study has examined their relation to epistemic curiosity - interest in symbolic, semantic information. To investigate this question, we tracked the eye movements of human observers while they read trivia questions and, after a brief delay, were visually given the answer. We show that higher curiosity was associated with earlier anticipatory orienting of gaze toward the answer location without changes in other metrics of saccades or fixations, and that these influences were distinct from those produced by variations in confidence and surprise. Across subjects, the enhancement of anticipatory gaze was correlated with measures of trait curiosity from personality questionnaires. Finally, a machine learning algorithm could predict curiosity in a cross-subject manner, relying primarily on statistical features of the gaze position before the answer onset and independently of covariations in confidence or surprise, suggesting potential practical applications for educational technologies, recommender systems and research in cognitive sciences. With this article, we provide full access to the annotated database allowing readers to reproduce the results. Epistemic curiosity produces specific effects on oculomotor anticipation that can be used to read out curiosity states. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

Processing Rhythmic Pattern during Chinese Sentence Reading: An Eye Movement Study

PubMed Central

Luo, Yingyi; Duan, Yunyan; Zhou, Xiaolin

2015-01-01

Prosodic constraints play a fundamental role during both spoken sentence comprehension and silent reading. In Chinese, the rhythmic pattern of the verb-object (V-O) combination has been found to rapidly affect the semantic access/integration process during sentence reading (Luo and Zhou, 2010). Rhythmic pattern refers to the combination of words with different syllabic lengths, with certain combinations disallowed (e.g., [2 + 1]; numbers standing for the number of syllables of the verb and the noun respectively) and certain combinations preferred (e.g., [1 + 1] or [2 + 2]). This constraint extends to the situation in which the combination is used to modify other words. A V-O phrase could modify a noun by simply preceding it, forming a V-O-N compound; when the verb is disyllabic, however, the word order has to be O-V-N and the object is preferred to be disyllabic. In this study, we investigated how the reader processes the rhythmic pattern and word order information by recording the reader's eye-movements. We created four types of sentences by crossing rhythmic pattern and word order in compounding. The compound, embedding a disyllabic verb, could be in the correct O-V-N or the incorrect V-O-N order; the object could be disyllabic or monosyllabic. We found that the reader spent more time and made more regressions on and after the compounds when either type of anomaly was detected during the first pass reading. However, during re-reading (after all the words in the sentence have been viewed), less regressive eye movements were found for the anomalous rhythmic pattern, relative to the correct pattern; moreover, only the abnormal rhythmic pattern, not the violated word order, influenced the regressive eye movements. These results suggest that while the processing of rhythmic pattern and word order information occurs rapidly during the initial reading of the sentence, the process of recovering from the rhythmic pattern anomaly may ease the reanalysis processing at the

Processing Rhythmic Pattern during Chinese Sentence Reading: An Eye Movement Study.

PubMed

Luo, Yingyi; Duan, Yunyan; Zhou, Xiaolin

2015-01-01

Prosodic constraints play a fundamental role during both spoken sentence comprehension and silent reading. In Chinese, the rhythmic pattern of the verb-object (V-O) combination has been found to rapidly affect the semantic access/integration process during sentence reading (Luo and Zhou, 2010). Rhythmic pattern refers to the combination of words with different syllabic lengths, with certain combinations disallowed (e.g., [2 + 1]; numbers standing for the number of syllables of the verb and the noun respectively) and certain combinations preferred (e.g., [1 + 1] or [2 + 2]). This constraint extends to the situation in which the combination is used to modify other words. A V-O phrase could modify a noun by simply preceding it, forming a V-O-N compound; when the verb is disyllabic, however, the word order has to be O-V-N and the object is preferred to be disyllabic. In this study, we investigated how the reader processes the rhythmic pattern and word order information by recording the reader's eye-movements. We created four types of sentences by crossing rhythmic pattern and word order in compounding. The compound, embedding a disyllabic verb, could be in the correct O-V-N or the incorrect V-O-N order; the object could be disyllabic or monosyllabic. We found that the reader spent more time and made more regressions on and after the compounds when either type of anomaly was detected during the first pass reading. However, during re-reading (after all the words in the sentence have been viewed), less regressive eye movements were found for the anomalous rhythmic pattern, relative to the correct pattern; moreover, only the abnormal rhythmic pattern, not the violated word order, influenced the regressive eye movements. These results suggest that while the processing of rhythmic pattern and word order information occurs rapidly during the initial reading of the sentence, the process of recovering from the rhythmic pattern anomaly may ease the reanalysis processing at the

Rapid eye movement sleep behaviour disorder and striatal dopamine depletion in patients with Parkinson's disease.

PubMed

Chung, S J; Lee, Y; Lee, J J; Lee, P H; Sohn, Y H

2017-10-01

Rapid eye movement sleep behaviour disorder (RBD) is related to striatal dopamine depletion. This study was performed to confirm whether clinically probable RBD (cpRBD) in patients with Parkinson's disease (PD) is associated with a specific pattern of striatal dopamine depletion. A prospective survey was conducted using the RBD Screening Questionnaire (RBDSQ) in 122 patients with PD who had undergone dopamine transporter (DAT) positron emission tomography scan. Patients with cpRBD (RBDSQ ≥ 7) exhibited greater motor deficits, predominantly in the less-affected side and axial symptoms, and were prescribed higher levodopa-equivalent doses at follow-up than those without cpRBD (RBDSQ ≤ 4), despite their similar disease and treatment durations. Compared to patients without cpRBD, those with cpRBD showed lower DAT activities in the putamen, particularly in the less-affected side in all putaminal subregions, and a tendency to be lower in the ventral striatum. In addition, greater motor deficits in patients with cpRBD than in those without cpRBD remained significant after controlling for DAT binding in the putamen and other confounding variables. These results demonstrated that the presence of RBD in patients with PD is associated with different patterns of both motor deficit distribution and striatal DAT depletion, suggesting that the presence of RBD represents a distinct PD subtype with a malignant motor parkinsonism. © 2017 EAN.

Effects of saccadic bilateral eye movements on episodic and semantic autobiographical memory fluency.

PubMed

Parker, Andrew; Parkin, Adam; Dagnall, Neil

2013-01-01

Performing a sequence of fast saccadic horizontal eye movements has been shown to facilitate performance on a range of cognitive tasks, including the retrieval of episodic memories. One explanation for these effects is based on the hypothesis that saccadic eye movements increase hemispheric interaction, and that such interactions are important for particular types of memory. The aim of the current research was to assess the effect of horizontal saccadic eye movements on the retrieval of both episodic autobiographical memory (event/incident based memory) and semantic autobiographical memory (fact based memory) over recent and more distant time periods. It was found that saccadic eye movements facilitated the retrieval of episodic autobiographical memories (over all time periods) but not semantic autobiographical memories. In addition, eye movements did not enhance the retrieval of non-autobiographical semantic memory. This finding illustrates a dissociation between the episodic and semantic characteristics of personal memory and is considered within the context of hemispheric contributions to episodic memory performance.

Effects of Saccadic Bilateral Eye Movements on Episodic and Semantic Autobiographical Memory Fluency

PubMed Central

Parker, Andrew; Parkin, Adam; Dagnall, Neil

2013-01-01

Performing a sequence of fast saccadic horizontal eye movements has been shown to facilitate performance on a range of cognitive tasks, including the retrieval of episodic memories. One explanation for these effects is based on the hypothesis that saccadic eye movements increase hemispheric interaction, and that such interactions are important for particular types of memory. The aim of the current research was to assess the effect of horizontal saccadic eye movements on the retrieval of both episodic autobiographical memory (event/incident based memory) and semantic autobiographical memory (fact based memory) over recent and more distant time periods. It was found that saccadic eye movements facilitated the retrieval of episodic autobiographical memories (over all time periods) but not semantic autobiographical memories. In addition, eye movements did not enhance the retrieval of non-autobiographical semantic memory. This finding illustrates a dissociation between the episodic and semantic characteristics of personal memory and is considered within the context of hemispheric contributions to episodic memory performance. PMID:24133435

Clinical-Radiologic Correlation of Extraocular Eye Movement Disorders: Seeing beneath the Surface.

PubMed

Thatcher, Joshua; Chang, Yu-Ming; Chapman, Margaret N; Hovis, Keegan; Fujita, Akifumi; Sobel, Rachel; Sakai, Osamu

2016-01-01

Extraocular eye movement disorders are relatively common and may be a significant source of discomfort and morbidity for patients. The presence of restricted eye movement can be detected clinically with quick, easily performed, noninvasive maneuvers that assess medial, lateral, upward, and downward gaze. However, detecting the presence of ocular dysmotility may not be sufficient to pinpoint the exact cause of eye restriction. Imaging plays an important role in excluding, in some cases, and detecting, in others, a specific cause responsible for the clinical presentation. However, the radiologist should be aware that the imaging findings in many of these conditions when taken in isolation from the clinical history and symptoms are often nonspecific. Normal eye movements are directly controlled by the ocular motor cranial nerves (CN III, IV, and VI) in coordination with indirect input or sensory stimuli derived from other cranial nerves. Specific causes of ocular dysmotility can be localized to the cranial nerve nuclei in the brainstem, the cranial nerve pathways in the peripheral nervous system, and the extraocular muscles in the orbit, with disease at any of these sites manifesting clinically as an eye movement disorder. A thorough understanding of central nervous system anatomy, cranial nerve pathways, and orbital anatomy, as well as familiarity with patterns of eye movement restriction, are necessary for accurate detection of radiologic abnormalities that support a diagnostic source of the suspected extraocular movement disorder. © RSNA, 2016.

Eye movements during listening reveal spontaneous grammatical processing.

PubMed

Huette, Stephanie; Winter, Bodo; Matlock, Teenie; Ardell, David H; Spivey, Michael

2014-01-01

Recent research using eye-tracking typically relies on constrained visual contexts in particular goal-oriented contexts, viewing a small array of objects on a computer screen and performing some overt decision or identification. Eyetracking paradigms that use pictures as a measure of word or sentence comprehension are sometimes touted as ecologically invalid because pictures and explicit tasks are not always present during language comprehension. This study compared the comprehension of sentences with two different grammatical forms: the past progressive (e.g., was walking), which emphasizes the ongoing nature of actions, and the simple past (e.g., walked), which emphasizes the end-state of an action. The results showed that the distribution and timing of eye movements mirrors the underlying conceptual structure of this linguistic difference in the absence of any visual stimuli or task constraint: Fixations were shorter and saccades were more dispersed across the screen, as if thinking about more dynamic events when listening to the past progressive stories. Thus, eye movement data suggest that visual inputs or an explicit task are unnecessary to solicit analog representations of features such as movement, that could be a key perceptual component to grammatical comprehension.

The role of eye movements in depth from motion parallax during infancy

PubMed Central

Nawrot, Elizabeth; Nawrot, Mark

2013-01-01

Motion parallax is a motion-based, monocular depth cue that uses an object's relative motion and velocity as a cue to relative depth. In adults, and in monkeys, a smooth pursuit eye movement signal is used to disambiguate the depth-sign provided by these relative motion cues. The current study investigates infants' perception of depth from motion parallax and the development of two oculomotor functions, smooth pursuit and the ocular following response (OFR) eye movements. Infants 8 to 20 weeks of age were presented with three tasks in a single session: depth from motion parallax, smooth pursuit tracking, and OFR to translation. The development of smooth pursuit was significantly related to age, as was sensitivity to motion parallax. OFR eye movements also corresponded to both age and smooth pursuit gain, with groups of infants demonstrating asymmetric function in both types of eye movements. These results suggest that the development of the eye movement system may play a crucial role in the sensitivity to depth from motion parallax in infancy. Moreover, describing the development of these oculomotor functions in relation to depth perception may aid in the understanding of certain visual dysfunctions. PMID:24353309

Exploring eye movements in patients with glaucoma when viewing a driving scene.

PubMed

Crabb, David P; Smith, Nicholas D; Rauscher, Franziska G; Chisholm, Catharine M; Barbur, John L; Edgar, David F; Garway-Heath, David F

2010-03-16

Glaucoma is a progressive eye disease and a leading cause of visual disability. Automated assessment of the visual field determines the different stages in the disease process: it would be desirable to link these measurements taken in the clinic with patient's actual function, or establish if patients compensate for their restricted field of view when performing everyday tasks. Hence, this study investigated eye movements in glaucomatous patients when viewing driving scenes in a hazard perception test (HPT). The HPT is a component of the UK driving licence test consisting of a series of short film clips of various traffic scenes viewed from the driver's perspective each containing hazardous situations that require the camera car to change direction or slow down. Data from nine glaucomatous patients with binocular visual field defects and ten age-matched control subjects were considered (all experienced drivers). Each subject viewed 26 different films with eye movements simultaneously monitored by an eye tracker. Computer software was purpose written to pre-process the data, co-register it to the film clips and to quantify eye movements and point-of-regard (using a dynamic bivariate contour ellipse analysis). On average, and across all HPT films, patients exhibited different eye movement characteristics to controls making, for example, significantly more saccades (P<0.001; 95% confidence interval for mean increase: 9.2 to 22.4%). Whilst the average region of 'point-of-regard' of the patients did not differ significantly from the controls, there were revealing cases where patients failed to see a hazard in relation to their binocular visual field defect. Characteristics of eye movement patterns in patients with bilateral glaucoma can differ significantly from age-matched controls when viewing a traffic scene. Further studies of eye movements made by glaucomatous patients could provide useful information about the definition of the visual field component required for

Tracking Without Perceiving: A Dissociation Between Eye Movements and Motion Perception

PubMed Central

Spering, Miriam; Pomplun, Marc; Carrasco, Marisa

2011-01-01

Can people react to objects in their visual field that they do not consciously perceive? We investigated how visual perception and motor action respond to moving objects whose visibility is reduced, and we found a dissociation between motion processing for perception and for action. We compared motion perception and eye movements evoked by two orthogonally drifting gratings, each presented separately to a different eye. The strength of each monocular grating was manipulated by inducing adaptation to one grating prior to the presentation of both gratings. Reflexive eye movements tracked the vector average of both gratings (pattern motion) even though perceptual responses followed one motion direction exclusively (component motion). Observers almost never perceived pattern motion. This dissociation implies the existence of visual-motion signals that guide eye movements in the absence of a corresponding conscious percept. PMID:21189353

Eye-Movement Parameters and Reading Speed.

ERIC Educational Resources Information Center

Sovik, Nils; Arntzen, Oddvar; Samuelstuen, Marit

2000-01-01

Addresses the relationship between four eye movement parameters and reading speed of 20 twelve-year-old children during silent and oral reading. Predicts reading speed by the following variables: recognition span, average fixation duration, and number of regressive saccades. Indicates that in terms of reading speed, significant interrelationships…

Use of a genetic algorithm for the analysis of eye movements from the linear vestibulo-ocular reflex

NASA Technical Reports Server (NTRS)

Shelhamer, M.

2001-01-01

It is common in vestibular and oculomotor testing to use a single-frequency (sine) or combination of frequencies [sum-of-sines (SOS)] stimulus for head or target motion. The resulting eye movements typically contain a smooth tracking component, which follows the stimulus, in which are interspersed rapid eye movements (saccades or fast phases). The parameters of the smooth tracking--the amplitude and phase of each component frequency--are of interest; many methods have been devised that attempt to identify and remove the fast eye movements from the smooth. We describe a new approach to this problem, tailored to both single-frequency and sum-of-sines stimulation of the human linear vestibulo-ocular reflex. An approximate derivative is used to identify fast movements, which are then omitted from further analysis. The remaining points form a series of smooth tracking segments. A genetic algorithm is used to fit these segments together to form a smooth (but disconnected) wave form, by iteratively removing biases due to the missing fast phases. A genetic algorithm is an iterative optimization procedure; it provides a basis for extending this approach to more complex stimulus-response situations. In the SOS case, the genetic algorithm estimates the amplitude and phase values of the component frequencies as well as removing biases.

Eye-movements intervening between two successive sounds disrupt comparisons of auditory location

PubMed Central

Pavani, Francesco; Husain, Masud; Driver, Jon

2008-01-01

Summary Many studies have investigated how saccades may affect the internal representation of visual locations across eye-movements. Here we studied instead whether eye-movements can affect auditory spatial cognition. In two experiments, participants judged the relative azimuth (same/different) of two successive sounds presented from a horizontal array of loudspeakers, separated by a 2.5 secs delay. Eye-position was either held constant throughout the trial (being directed in a fixed manner to the far left or right of the loudspeaker array), or had to be shifted to the opposite side of the array during the retention delay between the two sounds, after the first sound but before the second. Loudspeakers were either visible (Experiment1) or occluded from sight (Experiment 2). In both cases, shifting eye-position during the silent delay-period affected auditory performance in the successive auditory comparison task, even though the auditory inputs to be judged were equivalent. Sensitivity (d′) for the auditory discrimination was disrupted, specifically when the second sound shifted in the opposite direction to the intervening eye-movement with respect to the first sound. These results indicate that eye-movements affect internal representation of auditory location. PMID:18566808

Eye-movements intervening between two successive sounds disrupt comparisons of auditory location.

PubMed

Pavani, Francesco; Husain, Masud; Driver, Jon

2008-08-01

Many studies have investigated how saccades may affect the internal representation of visual locations across eye-movements. Here, we studied, instead, whether eye-movements can affect auditory spatial cognition. In two experiments, participants judged the relative azimuth (same/different) of two successive sounds presented from a horizontal array of loudspeakers, separated by a 2.5-s delay. Eye-position was either held constant throughout the trial (being directed in a fixed manner to the far left or right of the loudspeaker array) or had to be shifted to the opposite side of the array during the retention delay between the two sounds, after the first sound but before the second. Loudspeakers were either visible (Experiment 1) or occluded from sight (Experiment 2). In both cases, shifting eye-position during the silent delay-period affected auditory performance in thn the successive auditory comparison task, even though the auditory inputs to be judged were equivalent. Sensitivity (d') for the auditory discrimination was disrupted, specifically when the second sound shifted in the opposite direction to the intervening eye-movement with respect to the first sound. These results indicate that eye-movements affect internal representation of auditory location.

Like a rolling stone: naturalistic visual kinematics facilitate tracking eye movements.

PubMed

Souto, David; Kerzel, Dirk

2013-02-06

Newtonian physics constrains object kinematics in the real world. We asked whether eye movements towards tracked objects depend on their compliance with those constraints. In particular, the force of gravity constrains round objects to roll on the ground with a particular rotational and translational motion. We measured tracking eye movements towards rolling objects. We found that objects with rotational and translational motion that was congruent with an object rolling on the ground elicited faster tracking eye movements during pursuit initiation than incongruent stimuli. Relative to a condition without rotational component, we compared objects with this motion with a condition in which there was no rotational component, we essentially obtained benefits of congruence, and, to a lesser extent, costs from incongruence. Anticipatory pursuit responses showed no congruence effect, suggesting that the effect is based on visually-driven predictions, not on velocity storage. We suggest that the eye movement system incorporates information about object kinematics acquired by a lifetime of experience with visual stimuli obeying the laws of Newtonian physics.

Identification of cholinergic and non-cholinergic neurons in the pons expressing phosphorylated cyclic adenosine monophosphate response element-binding protein as a function of rapid eye movement sleep.

PubMed

Datta, S; Siwek, D F; Stack, E C

2009-09-29

Recent studies have shown that in the pedunculopontine tegmental nucleus (PPT), increased neuronal activity and kainate receptor-mediated activation of intracellular protein kinase A (PKA) are important physiological and molecular steps for the generation of rapid eye movement (REM) sleep. In the present study performed on rats, phosphorylated cyclic AMP response element-binding protein (pCREB) immunostaining was used as a marker for increased intracellular PKA activation and as a reflection of increased neuronal activity. To identify whether activated cells were either cholinergic or noncholinergic, the PPT and laterodorsal tegmental nucleus (LDT) cells were immunostained for choline acetyltransferase (ChAT) in combination with pCREB or c-Fos. The results demonstrated that during high rapid eye movement sleep (HR, approximately 27%), significantly higher numbers of cells expressed pCREB and c-Fos in the PPT, of which 95% of pCREB-expressing cells were ChAT-positive. With HR, the numbers of pCREB-positive cells were also significantly higher in the medial pontine reticular formation (mPRF), pontine reticular nucleus oral (PnO), and dorsal subcoeruleus nucleus (SubCD) but very few in the locus coeruleus (LC) and dorsal raphe nucleus (DRN). Conversely, with low rapid eye movement sleep (LR, approximately 2%), the numbers of pCREB expressing cells were very few in the PPT, mPRF, PnO, and SubCD but significantly higher in the LC and DRN. The results of regression analyses revealed significant positive relationships between the total percentages of REM sleep and numbers of ChAT+/pCREB+ (Rsqr=0.98) cells in the PPT and pCREB+ cells in the mPRF (Rsqr=0.88), PnO (Rsqr=0.87), and SubCD (Rsqr=0.84); whereas significantly negative relationships were associated with the pCREB+ cells in the LC (Rsqr=0.70) and DRN (Rsqr=0.60). These results provide evidence supporting the hypothesis that during REM sleep, the PPT cholinergic neurons are active, whereas the LC and DRN neurons are

Coming to grips with a "new" state of consciousness: the study of rapid-eye-movement sleep in the 1960s.

PubMed

Morrison, Adrian R

2013-01-01

The recognition of rapid-eye-movement sleep (REM) and its association with dreaming in 1953 by Aserinsky and Kleitman opened a new world to explore in the brain. Discussions at two major symposia in the early 1960s reveal that a state with characteristics resembling both wakefulness and sleep was overturning accepted views of the regulation of the two states. Participants grappled with the idea that cortical activation could occur during sleep. They struggled with picking a name that would capture the essence of REM without focusing on just one aspect of the state. Questioning whether REM in cats could be homologous with that of humans suggested an anthropocentric focus on human dreaming as the essence of the state. The need for biochemical studies was evident given that deprivation of REM caused a rebound in the amount of subsequent REM, which indicated that simple synaptic activity could not support this phenomenon.

Social Experience Does Not Abolish Cultural Diversity in Eye Movements

PubMed Central

Kelly, David J.; Jack, Rachael E.; Miellet, Sébastien; De Luca, Emanuele; Foreman, Kay; Caldara, Roberto

2011-01-01

Adults from Eastern (e.g., China) and Western (e.g., USA) cultural groups display pronounced differences in a range of visual processing tasks. For example, the eye movement strategies used for information extraction during a variety of face processing tasks (e.g., identification and facial expressions of emotion categorization) differs across cultural groups. Currently, many of the differences reported in previous studies have asserted that culture itself is responsible for shaping the way we process visual information, yet this has never been directly investigated. In the current study, we assessed the relative contribution of genetic and cultural factors by testing face processing in a population of British Born Chinese adults using face recognition and expression classification tasks. Contrary to predictions made by the cultural differences framework, the majority of British Born Chinese adults deployed “Eastern” eye movement strategies, while approximately 25% of participants displayed “Western” strategies. Furthermore, the cultural eye movement strategies used by individuals were consistent across recognition and expression tasks. These findings suggest that “culture” alone cannot straightforwardly account for diversity in eye movement patterns. Instead a more complex understanding of how the environment and individual experiences can influence the mechanisms that govern visual processing is required. PMID:21886626

Recognition method of construction conflict based on driver's eye movement.

PubMed

Xu, Yi; Li, Shiwu; Gao, Song; Tan, Derong; Guo, Dong; Wang, Yuqiong

2018-04-01

Drivers eye movement data in simulated construction conflicts at different speeds were collected and analyzed to find the relationship between the drivers' eye movement and the construction conflict. On the basis of the relationship between the drivers' eye movement and the construction conflict, the peak point of wavelet processed pupil diameter, the first point on the left side of the peak point and the first blink point after the peak point are selected as key points for locating construction conflict periods. On the basis of the key points and the GSA, a construction conflict recognition method so called the CCFRM is proposed. And the construction conflict recognition speed and location accuracy of the CCFRM are verified. The good performance of the CCFRM verified the feasibility of proposed key points in construction conflict recognition. Copyright © 2018 Elsevier Ltd. All rights reserved.

Binocular summation for reflexive eye movements

PubMed Central

Quaia, Christian; Optican, Lance M.; Cumming, Bruce G.

2018-01-01

Psychophysical studies and our own subjective experience suggest that, in natural viewing conditions (i.e., at medium to high contrasts), monocularly and binocularly viewed scenes appear very similar, with the exception of the improved depth perception provided by stereopsis. This phenomenon is usually described as a lack of binocular summation. We show here that there is an exception to this rule: Ocular following eye movements induced by the sudden motion of a large stimulus, which we recorded from three human subjects, are much larger when both eyes see the moving stimulus, than when only one eye does. We further discovered that this binocular advantage is a function of the interocular correlation between the two monocular images: It is maximal when they are identical, and reduced when the two eyes are presented with different images. This is possible only if the neurons that underlie ocular following are sensitive to binocular disparity. PMID:29621384

Quantitative EEG of Rapid-Eye-Movement Sleep: A Marker of Amnestic Mild Cognitive Impairment.

PubMed

Brayet, Pauline; Petit, Dominique; Frauscher, Birgit; Gagnon, Jean-François; Gosselin, Nadia; Gagnon, Katia; Rouleau, Isabelle; Montplaisir, Jacques

2016-04-01

The basal forebrain cholinergic system, which is impaired in early Alzheimer's disease, is more crucial for the activation of rapid-eye-movement (REM) sleep electroencephalogram (EEG) than it is for wakefulness. Quantitative EEG from REM sleep might thus provide an earlier and more accurate marker of the development of Alzheimer's disease in subjects with mild cognitive impairment (MCI) subjects than that from wakefulness. To assess the superiority of the REM sleep EEG as a screening tool for preclinical Alzheimer's disease, 22 subjects with amnestic MCI (a-MCI; 63.9±7.7 years), 10 subjects with nonamnestic MCI (na-MCI; 64.1±4.5 years) and 32 controls (63.7±6.6 years) participated in the study. Spectral analyses of the waking EEG and REM sleep EEG were performed and the [(delta+theta)/(alpha+beta)] ratio was used to assess between-group differences in EEG slowing. The a-MCI subgroup showed EEG slowing in frontal lateral regions compared to both na-MCI and control groups. This EEG slowing was present in wakefulness (compared to controls) but was much more prominent in REM sleep. Moreover, the comparison between amnestic and nonamnestic subjects was found significant only for the REM sleep EEG. There was no difference in EEG power ratio between na-MCI and controls for any of the 7 cortical regions studied. These findings demonstrate the superiority of the REM sleep EEG in the discrimination between a-MCI and both na-MCI and control subjects. © EEG and Clinical Neuroscience Society (ECNS) 2015.

Theta and gamma coordination of hippocampal networks during waking and rapid eye movement sleep.

PubMed

Montgomery, Sean M; Sirota, Anton; Buzsáki, György

2008-06-25

Rapid eye movement (REM) sleep has been considered a paradoxical state because, despite the high behavioral threshold to arousing perturbations, gross physiological patterns in the forebrain resemble those of waking states. To understand how intrahippocampal networks interact during REM sleep, we used 96 site silicon probes to record from different hippocampal subregions and compared the patterns of activity during waking exploration and REM sleep. Dentate/CA3 theta and gamma synchrony was significantly higher during REM sleep compared with active waking. In contrast, gamma power in CA1 and CA3-CA1 gamma coherence showed significant decreases in REM sleep. Changes in unit firing rhythmicity and unit-field coherence specified the local generation of these patterns. Although these patterns of hippocampal network coordination characterized the more common tonic periods of REM sleep (approximately 95% of total REM), we also detected large phasic bursts of local field potential power in the dentate molecular layer that were accompanied by transient increases in the firing of dentate and CA1 neurons. In contrast to tonic REM periods, phasic REM epochs were characterized by higher theta and gamma synchrony among the dentate, CA3, and CA1 regions. These data suggest enhanced dentate processing, but limited CA3-CA1 coordination during tonic REM sleep. In contrast, phasic bursts of activity during REM sleep may provide windows of opportunity to synchronize the hippocampal trisynaptic loop and increase output to cortical targets. We hypothesize that tonic REM sleep may support off-line mnemonic processing, whereas phasic bursts of activity during REM may promote memory consolidation.

Effects of reward on the accuracy and dynamics of smooth pursuit eye movements.

PubMed

Brielmann, Aenne A; Spering, Miriam

2015-08-01

Reward modulates behavioral choices and biases goal-oriented behavior, such as eye or hand movements, toward locations or stimuli associated with higher rewards. We investigated reward effects on the accuracy and timing of smooth pursuit eye movements in 4 experiments. Eye movements were recorded in participants tracking a moving visual target on a computer monitor. Before target motion onset, a monetary reward cue indicated whether participants could earn money by tracking accurately, or whether the trial was unrewarded (Experiments 1 and 2, n = 11 each). Reward significantly improved eye-movement accuracy across different levels of task difficulty. Improvements were seen even in the earliest phase of the eye movement, within 70 ms of tracking onset, indicating that reward impacts visual-motor processing at an early level. We obtained similar findings when reward was not precued but explicitly associated with the pursuit target (Experiment 3, n = 16); critically, these results were not driven by stimulus prevalence or other factors such as preparation or motivation. Numerical cues (Experiment 4, n = 9) were not effective. (c) 2015 APA, all rights reserved).

Saccadic eye movements analysis as a measure of drug effect on central nervous system function.

PubMed

Tedeschi, G; Quattrone, A; Bonavita, V

1986-04-01

Peak velocity (PSV) and duration (SD) of horizontal saccadic eye movements are demonstrably under the control of specific brain stem structures. Experimental and clinical evidence suggest the existence of an immediate premotor system for saccade generation located in the paramedian pontine reticular formation (PPRF). Effects on saccadic eye movements have been studied in normal volunteers with barbiturates, benzodiazepines, amphetamine and ethanol. On two occasions computer analysis of PSV, SD, saccade reaction time (SRT) and saccade accuracy (SA) was carried out in comparison with more traditional methods of assessment of human psychomotor performance like choice reaction time (CRT) and critical flicker fusion threshold (CFFT). The computer system proved to be a highly sensitive and objective method for measuring drug effect on central nervous system (CNS) function. It allows almost continuous sampling of data and appears to be particularly suitable for studying rapidly changing drug effects on the CNS.

The role of eye movements in decision making and the prospect of exposure effects.

PubMed

Bird, Gary D; Lauwereyns, Johan; Crawford, Matthew T

2012-05-01

The aim of the current study was to follow on from previous findings that eye movements can have a causal influence on preference formation. Shimojo et al. (2003) previously found that faces that were presented for a longer duration in a two alternative forced choice task were more likely to be judged as more attractive. This effect only occurred when an eye movement was made towards the faces (with no effect when faces were centrally presented). The current study replicated Shimojo et al.'s (2003) design, whilst controlling for potential inter-stimuli interference in central presentations. As per previous findings, when eye movements were made towards the stimuli, faces that were presented for longer durations were preferred. However, faces that were centrally presented (thus not requiring an eye movement) were also preferred in the current study. The presence of an exposure duration effect for centrally presented faces casts doubt on the necessity of the eye movement in this decision making process and has implications for decision theories that place an emphasis on the role of eye movements in decision making. Copyright © 2012 Elsevier Ltd. All rights reserved.

Using eye movements to explore mental representations of space.

PubMed

Fourtassi, Maryam; Rode, Gilles; Pisella, Laure

2017-06-01

Visual mental imagery is a cognitive experience characterised by the activation of the mental representation of an object or scene in the absence of the corresponding stimulus. According to the analogical theory, mental representations have a pictorial nature that preserves the spatial characteristics of the environment that is mentally represented. This cognitive experience shares many similarities with the experience of visual perception, including eye movements. The mental visualisation of a scene is accompanied by eye movements that reflect the spatial content of the mental image, and which can mirror the deformations of this mental image with respect to the real image, such as asymmetries or size reduction. The present article offers a concise overview of the main theories explaining the interactions between eye movements and mental representations, with some examples of the studies supporting them. It also aims to explain how ocular-tracking could be a useful tool in exploring the dynamics of spatial mental representations, especially in pathological situations where these representations can be altered, for instance in unilateral spatial neglect. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

CEFR and Eye Movement Characteristics during EFL Reading: The Case of Intermediate Readers

ERIC Educational Resources Information Center

Dolgunsöz, Emrah; Sariçoban, Arif

2016-01-01

This study primarily aims to (1) examine the relationship between foreign language reading proficiency and eye movements during reading, and (2) to describe eye movement differences between two CEFR proficiency groups (B1 and B2) by using eye tracking technique. 57 learners of EFL were tested under two experimental conditions: Natural L2 reading…

[Eye movement study in multiple object search process].

PubMed

Xu, Zhaofang; Liu, Zhongqi; Wang, Xingwei; Zhang, Xin

2017-04-01

The aim of this study is to investigate the search time regulation of objectives and eye movement behavior characteristics in the multi-objective visual search. The experimental task was accomplished with computer programming and presented characters on a 24 inch computer display. The subjects were asked to search three targets among the characters. Three target characters in the same group were of high similarity degree while those in different groups of target characters and distraction characters were in different similarity degrees. We recorded the search time and eye movement data through the whole experiment. It could be seen from the eye movement data that the quantity of fixation points was large when the target characters and distraction characters were similar. There were three kinds of visual search patterns for the subjects including parallel search, serial search, and parallel-serial search. In addition, the last pattern had the best search performance among the three search patterns, that is, the subjects who used parallel-serial search pattern spent shorter time finding the target. The order that the targets presented were able to affect the search performance significantly; and the similarity degree between target characters and distraction characters could also affect the search performance.

Using E-Z Reader to Simulate Eye Movements in Nonreading Tasks: A Unified Framework for Understanding the Eye-Mind Link

ERIC Educational Resources Information Center

Reichle, Erik D.; Pollatsek, Alexander; Rayner, Keith

2012-01-01

Nonreading tasks that share some (but not all) of the task demands of reading have often been used to make inferences about how cognition influences when the eyes move during reading. In this article, we use variants of the E-Z Reader model of eye-movement control in reading to simulate eye-movement behavior in several of these tasks, including…

Rapid Eye Movement Sleep in Relation to Overweight in Children and Adolescents

PubMed Central

Liu, Xianchen; Forbes, Erika E.; Ryan, Neal D.; Rofey, Dana; Hannon, Tamara S.; Dahl, Ronald E.

2009-01-01

Context Short sleep duration is associated with obesity, but few studies have examined the relationship between obesity and specific physiological stages of sleep. Objective To examine specific sleep stages, including rapid eye movement (REM) sleep and stages 1 through 4 of non-REM sleep, in relation to overweight in children and adolescents. Design, Setting, and Participants A total of 335 children and adolescents (55.2% male; aged 7-17 years) underwent 3 consecutive nights of standard polysomnography and weight and height assessments as part of a study on the development of internalizing disorders (depression and anxiety). Main Outcome Measures Body mass index (calculated as weight in kilograms divided by height in meters squared) z score and weight status (normal, at risk for overweight, overweight) according to the body mass index percentile for age and sex. Results The body mass index z score was significantly related to total sleep time (β=-0.174), sleep efficiency (β=-0.027), and REM density (β=-0.256). Compared with normal-weight children, overweight children slept about 22 minutes less and had lower sleep efficiency, shorter REM sleep, lower REM activity and density, and longer latency to the first REM period. After adjustment for demographics, pubertal status, and psychiatric diagnosis, 1 hour less of total sleep was associated with approximately 2-fold increased odds of overweight (odds ratio=1.85), 1 hour less of REM sleep was associated with about 3-fold increased odds (odds ratio=2.91), and REM density and activity below the median increased the odds of overweight by 2-fold (odds ratio=2.18) and 3-fold (odds ratio=3.32), respectively. Conclusions Our results confirm previous epidemiological observations that short sleep time is associated with overweight in children and adolescents. A core aspect of the association between short sleep duration and overweight may be attributed to reduced REM sleep. Further studies are needed to investigate possible

Exploring Eye Movements in Patients with Glaucoma When Viewing a Driving Scene

PubMed Central

Crabb, David P.; Smith, Nicholas D.; Rauscher, Franziska G.; Chisholm, Catharine M.; Barbur, John L.; Edgar, David F.; Garway-Heath, David F.

2010-01-01

Background Glaucoma is a progressive eye disease and a leading cause of visual disability. Automated assessment of the visual field determines the different stages in the disease process: it would be desirable to link these measurements taken in the clinic with patient's actual function, or establish if patients compensate for their restricted field of view when performing everyday tasks. Hence, this study investigated eye movements in glaucomatous patients when viewing driving scenes in a hazard perception test (HPT). Methodology/Principal Findings The HPT is a component of the UK driving licence test consisting of a series of short film clips of various traffic scenes viewed from the driver's perspective each containing hazardous situations that require the camera car to change direction or slow down. Data from nine glaucomatous patients with binocular visual field defects and ten age-matched control subjects were considered (all experienced drivers). Each subject viewed 26 different films with eye movements simultaneously monitored by an eye tracker. Computer software was purpose written to pre-process the data, co-register it to the film clips and to quantify eye movements and point-of-regard (using a dynamic bivariate contour ellipse analysis). On average, and across all HPT films, patients exhibited different eye movement characteristics to controls making, for example, significantly more saccades (P<0.001; 95% confidence interval for mean increase: 9.2 to 22.4%). Whilst the average region of ‘point-of-regard’ of the patients did not differ significantly from the controls, there were revealing cases where patients failed to see a hazard in relation to their binocular visual field defect. Conclusions/Significance Characteristics of eye movement patterns in patients with bilateral glaucoma can differ significantly from age-matched controls when viewing a traffic scene. Further studies of eye movements made by glaucomatous patients could provide useful

Cognitive Control of Saccadic Eye Movements

ERIC Educational Resources Information Center

Hutton, S. B.

2008-01-01

The saccadic eye movement system provides researchers with a powerful tool with which to explore the cognitive control of behaviour. It is a behavioural system whose limited output can be measured with exceptional precision, and whose input can be controlled and manipulated in subtle ways. A range of cognitive processes (notably those involved in…

Listening to music reduces eye movements.

PubMed

Schäfer, Thomas; Fachner, Jörg

2015-02-01

Listening to music can change the way that people visually experience the environment, probably as a result of an inwardly directed shift of attention. We investigated whether this attentional shift can be demonstrated by reduced eye movement activity, and if so, whether that reduction depends on absorption. Participants listened to their preferred music, to unknown neutral music, or to no music while viewing a visual stimulus (a picture or a film clip). Preference and absorption were significantly higher for the preferred music than for the unknown music. Participants exhibited longer fixations, fewer saccades, and more blinks when they listened to music than when they sat in silence. However, no differences emerged between the preferred music condition and the neutral music condition. Thus, music significantly reduces eye movement activity, but an attentional shift from the outer to the inner world (i.e., to the emotions and memories evoked by the music) emerged as only one potential explanation. Other explanations, such as a shift of attention from visual to auditory input, are discussed.

The utility of modeling word identification from visual input within models of eye movements in reading

PubMed Central

Bicknell, Klinton; Levy, Roger

2012-01-01

Decades of empirical work have shown that a range of eye movement phenomena in reading are sensitive to the details of the process of word identification. Despite this, major models of eye movement control in reading do not explicitly model word identification from visual input. This paper presents a argument for developing models of eye movements that do include detailed models of word identification. Specifically, we argue that insights into eye movement behavior can be gained by understanding which phenomena naturally arise from an account in which the eyes move for efficient word identification, and that one important use of such models is to test which eye movement phenomena can be understood this way. As an extended case study, we present evidence from an extension of a previous model of eye movement control in reading that does explicitly model word identification from visual input, Mr. Chips (Legge, Klitz, & Tjan, 1997), to test two proposals for the effect of using linguistic context on reading efficiency. PMID:23074362

Destabilizing effects of visual environment motions simulating eye movements or head movements

NASA Technical Reports Server (NTRS)

White, Keith D.; Shuman, D.; Krantz, J. H.; Woods, C. B.; Kuntz, L. A.

1991-01-01

In the present paper, we explore effects on the human of exposure to a visual virtual environment which has been enslaved to simulate the human user's head movements or eye movements. Specifically, we have studied the capacity of our experimental subjects to maintain stable spatial orientation in the context of moving their entire visible surroundings by using the parameters of the subjects' natural movements. Our index of the subjects' spatial orientation was the extent of involuntary sways of the body while attempting to stand still, as measured by translations and rotations of the head. We also observed, informally, their symptoms of motion sickness.

Properties of cerebellar fastigial neurons during translation, rotation, and eye movements

NASA Technical Reports Server (NTRS)

Shaikh, Aasef G.; Ghasia, Fatema F.; Dickman, J. David; Angelaki, Dora E.

2005-01-01

The most medial of the deep cerebellar nuclei, the fastigial nucleus (FN), receives sensory vestibular information and direct inhibition from the cerebellar vermis. We investigated the signal processing in the primate FN by recording single-unit activities during translational motion, rotational motion, and eye movements. Firing rate modulation during horizontal plane translation in the absence of eye movements was observed in all non-eye-movement-sensitive cells and 26% of the pursuit eye-movement-sensitive neurons in the caudal FN. Many non-eye-movement-sensitive cells recorded in the rostral FN of three fascicularis monkeys exhibited convergence of signals from both the otolith organs and the semicircular canals. At low frequencies of translation, the majority of these rostral FN cells changed their firing rates in phase with head velocity rather than linear acceleration. As frequency increased, FN vestibular neurons exhibited a wide range of response dynamics with most cells being characterized by increasing phase leads as a function of frequency. Unlike cells in the vestibular nuclei, none of the rostral FN cells responded to rotational motion alone, without simultaneously exhibiting sensitivity to translational motion. Modulation during earth-horizontal axis rotation was observed in more than half (77%) of the neurons, although with smaller gains than during translation. In contrast, only 47% of the cells changed their firing rates during earth-vertical axis rotations in the absence of a dynamic linear acceleration stimulus. These response properties suggest that the rostral FN represents a main processing center of otolith-driven information for inertial motion detection and spatial orientation.

Coordination of eye and head components of movements evoked by stimulation of the paramedian pontine reticular formation.

PubMed

Gandhi, Neeraj J; Barton, Ellen J; Sparks, David L

2008-07-01

Constant frequency microstimulation of the paramedian pontine reticular formation (PPRF) in head-restrained monkeys evokes a constant velocity eye movement. Since the PPRF receives significant projections from structures that control coordinated eye-head movements, we asked whether stimulation of the pontine reticular formation in the head-unrestrained animal generates a combined eye-head movement or only an eye movement. Microstimulation of most sites yielded a constant-velocity gaze shift executed as a coordinated eye-head movement, although eye-only movements were evoked from some sites. The eye and head contributions to the stimulation-evoked movements varied across stimulation sites and were drastically different from the lawful relationship observed for visually-guided gaze shifts. These results indicate that the microstimulation activated elements that issued movement commands to the extraocular and, for most sites, neck motoneurons. In addition, the stimulation-evoked changes in gaze were similar in the head-restrained and head-unrestrained conditions despite the assortment of eye and head contributions, suggesting that the vestibulo-ocular reflex (VOR) gain must be near unity during the coordinated eye-head movements evoked by stimulation of the PPRF. These findings contrast the attenuation of VOR gain associated with visually-guided gaze shifts and suggest that the vestibulo-ocular pathway processes volitional and PPRF stimulation-evoked gaze shifts differently.

More to it than meets the eye: how eye movements can elucidate the development of episodic memory.

PubMed

Pathman, Thanujeni; Ghetti, Simona

2016-07-01

The ability to recognise past events along with the contexts in which they occurred is a hallmark of episodic memory, a critical capacity. Eye movements have been shown to track veridical memory for the associations between events and their contexts (relational binding). Such eye-movement effects emerge several seconds before, or in the absence of, explicit response, and are linked to the integrity and function of the hippocampus. Drawing from research from infancy through late childhood, and by comparing to investigations from typical adults, patient populations, and animal models, it seems increasingly clear that eye movements reflect item-item, item-temporal, and item-spatial associations in developmental populations. We analyse this line of work, identify missing pieces in the literature and outline future avenues of research, in order to help elucidate the development of episodic memory.

Visual Short-Term Memory During Smooth Pursuit Eye Movements

ERIC Educational Resources Information Center

Kerzel, Dirk; Ziegler, Nathalie E.

2005-01-01

Visual short-term memory (VSTM) was probed while observers performed smooth pursuit eye movements. Smooth pursuit keeps a moving object stabilized in the fovea. VSTM capacity for position was reduced during smooth pursuit compared with a condition with eye fixation. There was no difference between a condition in which the items were approximately…

Tracking the Eye Movement of Four Years Old Children Learning Chinese Words

ERIC Educational Resources Information Center

Lin, Dan; Chen, Guangyao; Liu, Yingyi; Liu, Jiaxin; Pan, Jue; Mo, Lei

2018-01-01

Storybook reading is the major source of literacy exposure for beginning readers. The present study tracked 4-year-old Chinese children's eye movements while they were reading simulated storybook pages. Their eye-movement patterns were examined in relation to their word learning gains. The same reading list, consisting of 20 two-character Chinese…

Effects of Peripheral Visual Field Loss on Eye Movements During Visual Search

PubMed Central

Wiecek, Emily; Pasquale, Louis R.; Fiser, Jozsef; Dakin, Steven; Bex, Peter J.

2012-01-01

Natural vision involves sequential eye movements that bring the fovea to locations selected by peripheral vision. How peripheral visual field loss (PVFL) affects this process is not well understood. We examine how the location and extent of PVFL affects eye movement behavior in a naturalistic visual search task. Ten patients with PVFL and 13 normally sighted subjects with full visual fields (FVF) completed 30 visual searches monocularly. Subjects located a 4° × 4° target, pseudo-randomly selected within a 26° × 11° natural image. Eye positions were recorded at 50 Hz. Search duration, fixation duration, saccade size, and number of saccades per trial were not significantly different between PVFL and FVF groups (p > 0.1). A χ2 test showed that the distributions of saccade directions for PVFL and FVL subjects were significantly different in 8 out of 10 cases (p < 0.01). Humphrey Visual Field pattern deviations for each subject were compared with the spatial distribution of eye movement directions. There were no significant correlations between saccade directional bias and visual field sensitivity across the 10 patients. Visual search performance was not significantly affected by PVFL. An analysis of eye movement directions revealed patients with PVFL show a biased directional distribution that was not directly related to the locus of vision loss, challenging feed-forward models of eye movement control. Consequently, many patients do not optimally compensate for visual field loss during visual search. PMID:23162511

High-Speed Video-Oculography for Measuring Three-Dimensional Rotation Vectors of Eye Movements in Mice

PubMed Central

Takeda, Noriaki; Uno, Atsuhiko; Inohara, Hidenori; Shimada, Shoichi

2016-01-01

Background The mouse is the most commonly used animal model in biomedical research because of recent advances in molecular genetic techniques. Studies related to eye movement in mice are common in fields such as ophthalmology relating to vision, neuro-otology relating to the vestibulo-ocular reflex (VOR), neurology relating to the cerebellum’s role in movement, and psychology relating to attention. Recording eye movements in mice, however, is technically difficult. Methods We developed a new algorithm for analyzing the three-dimensional (3D) rotation vector of eye movement in mice using high-speed video-oculography (VOG). The algorithm made it possible to analyze the gain and phase of VOR using the eye’s angular velocity around the axis of eye rotation. Results When mice were rotated at 0.5 Hz and 2.5 Hz around the earth’s vertical axis with their heads in a 30° nose-down position, the vertical components of their left eye movements were in phase with the horizontal components. The VOR gain was 0.42 at 0.5 Hz and 0.74 at 2.5 Hz, and the phase lead of the eye movement against the turntable was 16.1° at 0.5 Hz and 4.88° at 2.5 Hz. Conclusions To the best of our knowledge, this is the first report of this algorithm being used to calculate a 3D rotation vector of eye movement in mice using high-speed VOG. We developed a technique for analyzing the 3D rotation vector of eye movements in mice with a high-speed infrared CCD camera. We concluded that the technique is suitable for analyzing eye movements in mice. We also include a C++ source code that can calculate the 3D rotation vectors of the eye position from two-dimensional coordinates of the pupil and the iris freckle in the image to this article. PMID:27023859

Is adaptation to perceived interocular differences in height explained by vertical fusional eye movements?

PubMed

Maier, Felix M; Schaeffel, Frank

2013-07-24

To find out whether adaptation to a vertical prism involves more than fusional vertical eye movements. Adaptation to a vertical base-up 3 prism diopter prism was measured in a custom-programmed Maddox test in nine visually normal emmetropic subjects (mean age 27.0 ± 2.8 years). Vertical eye movements were binocularly measured in six of the subjects with a custom-programmed binocular video eye tracker. In the Maddox test, some subjects adjusted the perceived height as expected from the power of the prism while others appeared to ignore the prism. After 15 minutes of adaptation, the interocular difference in perceived height was reduced by on average 51% (from 0.86°-0.44°). The larger the initially perceived difference in height in a subject, the larger the amplitude of adaptation was. Eye tracking showed that the prism generated divergent vertical eye movements of 1.2° on average, which was less than expected from its power. Differences in eye elevation were maintained as long as the prism was in place. Small angles of lateral head tilt generated large interocular differences in eye elevation, much larger than the effects introduced by the prism. Vertical differences in retinal image height were compensated by vertical fusional eye movements but some subjects responded poorly to a vertical prism in both experiments; fusional eye movements were generally too small to realign both foveae with the fixation target; and the prism adaptation in the Maddox test was fully explained by the changes in vertical eye position, suggesting that no further adaptational mechanism may be involved.

Neocortical 40 Hz oscillations during carbachol-induced rapid eye movement sleep and cataplexy.

PubMed

Torterolo, Pablo; Castro-Zaballa, Santiago; Cavelli, Matías; Chase, Michael H; Falconi, Atilio

2016-02-01

Higher cognitive functions require the integration and coordination of large populations of neurons in cortical and subcortical regions. Oscillations in the gamma band (30-45 Hz) of the electroencephalogram (EEG) have been involved in these cognitive functions. In previous studies, we analysed the extent of functional connectivity between cortical areas employing the 'mean squared coherence' analysis of the EEG gamma band. We demonstrated that gamma coherence is maximal during alert wakefulness and is almost absent during rapid eye movement (REM) sleep. The nucleus pontis oralis (NPO) is critical for REM sleep generation. The NPO is considered to exert executive control over the initiation and maintenance of REM sleep. In the cat, depending on the previous state of the animal, a single microinjection of carbachol (a cholinergic agonist) into the NPO can produce either REM sleep [REM sleep induced by carbachol (REMc)] or a waking state with muscle atonia, i.e. cataplexy [cataplexy induced by carbachol (CA)]. In the present study, in cats that were implanted with electrodes in different cortical areas to record polysomnographic activity, we compared the degree of gamma (30-45 Hz) coherence during REMc, CA and naturally-occurring behavioural states. Gamma coherence was maximal during CA and alert wakefulness. In contrast, gamma coherence was almost absent during REMc as in naturally-occurring REM sleep. We conclude that, in spite of the presence of somatic muscle paralysis, there are remarkable differences in cortical activity between REMc and CA, which confirm that EEG gamma (≈40 Hz) coherence is a trait that differentiates wakefulness from REM sleep. © 2015 Federation of European Neuroscience Societies and John Wiley & Sons Ltd.

Execution of saccadic eye movements affects speed perception

PubMed Central

Goettker, Alexander; Braun, Doris I.; Schütz, Alexander C.; Gegenfurtner, Karl R.

2018-01-01

Due to the foveal organization of our visual system we have to constantly move our eyes to gain precise information about our environment. Doing so massively alters the retinal input. This is problematic for the perception of moving objects, because physical motion and retinal motion become decoupled and the brain has to discount the eye movements to recover the speed of moving objects. Two different types of eye movements, pursuit and saccades, are combined for tracking. We investigated how the way we track moving targets can affect the perceived target speed. We found that the execution of corrective saccades during pursuit initiation modifies how fast the target is perceived compared with pure pursuit. When participants executed a forward (catch-up) saccade they perceived the target to be moving faster. When they executed a backward saccade they perceived the target to be moving more slowly. Variations in pursuit velocity without corrective saccades did not affect perceptual judgments. We present a model for these effects, assuming that the eye velocity signal for small corrective saccades gets integrated with the retinal velocity signal during pursuit. In our model, the execution of corrective saccades modulates the integration of these two signals by giving less weight to the retinal information around the time of corrective saccades. PMID:29440494

Gender Classification Based on Eye Movements: A Processing Effect During Passive Face Viewing

PubMed Central

Sammaknejad, Negar; Pouretemad, Hamidreza; Eslahchi, Changiz; Salahirad, Alireza; Alinejad, Ashkan

2017-01-01

Studies have revealed superior face recognition skills in females, partially due to their different eye movement strategies when encoding faces. In the current study, we utilized these slight but important differences and proposed a model that estimates the gender of the viewers and classifies them into two subgroups, males and females. An eye tracker recorded participant’s eye movements while they viewed images of faces. Regions of interest (ROIs) were defined for each face. Results showed that the gender dissimilarity in eye movements was not due to differences in frequency of fixations in the ROI s per se. Instead, it was caused by dissimilarity in saccade paths between the ROIs. The difference enhanced when saccades were towards the eyes. Females showed significant increase in transitions from other ROI s to the eyes. Consequently, the extraction of temporal transient information of saccade paths through a transition probability matrix, similar to a first order Markov chain model, significantly improved the accuracy of the gender classification results. PMID:29071007

Gender Classification Based on Eye Movements: A Processing Effect During Passive Face Viewing.

PubMed

Sammaknejad, Negar; Pouretemad, Hamidreza; Eslahchi, Changiz; Salahirad, Alireza; Alinejad, Ashkan

2017-01-01

Studies have revealed superior face recognition skills in females, partially due to their different eye movement strategies when encoding faces. In the current study, we utilized these slight but important differences and proposed a model that estimates the gender of the viewers and classifies them into two subgroups, males and females. An eye tracker recorded participant's eye movements while they viewed images of faces. Regions of interest (ROIs) were defined for each face. Results showed that the gender dissimilarity in eye movements was not due to differences in frequency of fixations in the ROI s per se. Instead, it was caused by dissimilarity in saccade paths between the ROIs. The difference enhanced when saccades were towards the eyes. Females showed significant increase in transitions from other ROI s to the eyes. Consequently, the extraction of temporal transient information of saccade paths through a transition probability matrix, similar to a first order Markov chain model, significantly improved the accuracy of the gender classification results.

Smooth-pursuit eye-movement deficits with chemical lesions in macaque nucleus reticularis tegmenti pontis.

PubMed

Suzuki, D A; Yamada, T; Hoedema, R; Yee, R D

1999-09-01

Anatomic and neuronal recordings suggest that the nucleus reticularis tegmenti pontis (NRTP) of macaques may be a major pontine component of a cortico-ponto-cerebellar pathway that subserves the control of smooth-pursuit eye movements. The existence of such a pathway was implicated by the lack of permanent pursuit impairment after bilateral lesions in the dorsolateral pontine nucleus. To provide more direct evidence that NRTP is involved with regulating smooth-pursuit eye movements, chemical lesions were made in macaque NRTP by injecting either lidocaine or ibotenic acid. Injection sites first were identified by the recording of smooth-pursuit-related modulations in neuronal activity. The resulting lesions caused significant deficits in both the maintenance and the initiation of smooth-pursuit eye movements. After lesion formation, the gain of constant-velocity, maintained smooth-pursuit eye movements decreased, on the average, by 44%. Recovery of the ability to maintain smooth-pursuit eye movements occurred over approximately 3 days when maintained pursuit gains attained normal values. The step-ramp, "Rashbass" task was used to investigate the effects of the lesions on the initiation of smooth-pursuit eye movements. Eye accelerations averaged over the initial 80 ms of pursuit initiation were determined and found to be decremented, on the average, by 48% after the administration of ibotenic acid. Impairments in the initiation and maintenance of smooth-pursuit eye movements were directional in nature. Upward pursuit seemed to be the most vulnerable and was impaired in all cases independent of lesioning agent and type of pursuit investigated. Downward smooth pursuit seemed more resistant to the effects of chemical lesions in NRTP. Impairments in horizontal tracking were observed with examples of deficits in ipsilaterally and contralaterally directed pursuit. The results provide behavioral support for the physiologically and anatomic-based conclusion that NRTP is a

Eye Movement Monitoring in the Study of Silent Reading.

ERIC Educational Resources Information Center

McConkie, George W.

Eye movement monitoring is useful both in the control of experiments on reading and as a source of data. Experiments using eye monitoring techniques have helped develop the following conclusions about the reading process: the region of text read during a fixation is quite small and asymmetric to the right of the center of vision, successive…

Horizontal Saccadic Eye Movements Enhance the Retrieval of Landmark Shape and Location Information

ERIC Educational Resources Information Center

Brunye, Tad T.; Mahoney, Caroline R.; Augustyn, Jason S.; Taylor, Holly A.

2009-01-01

Recent work has demonstrated that horizontal saccadic eye movements enhance verbal episodic memory retrieval, particularly in strongly right-handed individuals. The present experiments test three primary assumptions derived from this research. First, horizontal eye movements should facilitate episodic memory for both verbal and non-verbal…

Magnifying visual target information and the role of eye movements in motor sequence learning.

PubMed

Massing, Matthias; Blandin, Yannick; Panzer, Stefan

2016-01-01

An experiment investigated the influence of eye movements on learning a simple motor sequence task when the visual display was magnified. The task was to reproduce a 1300 ms spatial-temporal pattern of elbow flexions and extensions. The spatial-temporal pattern was displayed in front of the participants. Participants were randomly assigned to four groups differing on eye movements (free to use their eyes/instructed to fixate) and the visual display (small/magnified). All participants had to perform a pre-test, an acquisition phase, a delayed retention test, and a transfer test. The results indicated that participants in each practice condition increased their performance during acquisition. The participants who were permitted to use their eyes in the magnified visual display outperformed those who were instructed to fixate on the magnified visual display. When a small visual display was used, the instruction to fixate induced no performance decrements compared to participants who were permitted to use their eyes during acquisition. The findings demonstrated that a spatial-temporal pattern can be learned without eye movements, but being permitting to use eye movements facilitates the response production when the visual angle is increased. Copyright © 2015 Elsevier B.V. All rights reserved.

Tracking Students' Cognitive Processes during Program Debugging--An Eye-Movement Approach

ERIC Educational Resources Information Center

Lin, Yu-Tzu; Wu, Cheng-Chih; Hou, Ting-Yun; Lin, Yu-Chih; Yang, Fang-Ying; Chang, Chia-Hu

2016-01-01

This study explores students' cognitive processes while debugging programs by using an eye tracker. Students' eye movements during debugging were recorded by an eye tracker to investigate whether and how high- and low-performance students act differently during debugging. Thirty-eight computer science undergraduates were asked to debug two C…

Dissociable Stages of Problem Solving (I): Temporal Characteristics Revealed by Eye-Movement Analyses

ERIC Educational Resources Information Center

Nitschke, Kai; Ruh, Nina; Kappler, Sonja; Stahl, Christoph; Kaller, Christoph P.

2012-01-01

Understanding the functional neuroanatomy of planning and problem solving may substantially benefit from better insight into the chronology of the cognitive processes involved. Based on the assumption that regularities in cognitive processing are reflected in overtly observable eye-movement patterns, here we recorded eye movements while…

Eye Movements in Implicit Artificial Grammar Learning

ERIC Educational Resources Information Center

Silva, Susana; Inácio, Filomena; Folia, Vasiliki; Petersson, Karl Magnus

2017-01-01

Artificial grammar learning (AGL) has been probed with forced-choice behavioral tests (active tests). Recent attempts to probe the outcomes of learning (implicitly acquired knowledge) with eye-movement responses (passive tests) have shown null results. However, these latter studies have not tested for sensitivity effects, for example, increased…

Pharmacological Treatment Effects on Eye Movement Control

ERIC Educational Resources Information Center

Reilly, James L.; Lencer, Rebekka; Bishop, Jeffrey R.; Keedy, Sarah; Sweeney, John A.

2008-01-01

The increasing use of eye movement paradigms to assess the functional integrity of brain systems involved in sensorimotor and cognitive processing in clinical disorders requires greater attention to effects of pharmacological treatments on these systems. This is needed to better differentiate disease and medication effects in clinical samples, to…

A relationship between eye movement patterns and performance in a precognitive tracking task

NASA Technical Reports Server (NTRS)

Repperger, D. W.; Hartzell, E. J.

1977-01-01

Eye movements made by various subjects in the performance of a precognitive tracking task are studied. The tracking task persented by an antiaircraft artillery (AAA) simulator has an input forcing function represented by a deterministic aircraft fly-by. The performance of subjects is ranked by two metrics. Good, mediocre, and poor trackers are selected for analysis based on performance during the difficult segment of the tracking task and over replications. Using phase planes to characterize both the eye movement patterns and the displayed error signal, a simple metric is developed to study these patterns. Two characterizations of eye movement strategies are defined and quantified. Using these two types of eye strategies, two conclusions are obtained about good, mediocre, and poor trackers. First, the eye tracker who used a fixed strategy will consistently perform better. Secondly, the best fixed strategy is defined as a Crosshair Fixator.

Toward statistical modeling of saccadic eye-movement and visual saliency.

PubMed

Sun, Xiaoshuai; Yao, Hongxun; Ji, Rongrong; Liu, Xian-Ming

2014-11-01

In this paper, we present a unified statistical framework for modeling both saccadic eye movements and visual saliency. By analyzing the statistical properties of human eye fixations on natural images, we found that human attention is sparsely distributed and usually deployed to locations with abundant structural information. This observations inspired us to model saccadic behavior and visual saliency based on super-Gaussian component (SGC) analysis. Our model sequentially obtains SGC using projection pursuit, and generates eye movements by selecting the location with maximum SGC response. Besides human saccadic behavior simulation, we also demonstrated our superior effectiveness and robustness over state-of-the-arts by carrying out dense experiments on synthetic patterns and human eye fixation benchmarks. Multiple key issues in saliency modeling research, such as individual differences, the effects of scale and blur, are explored in this paper. Based on extensive qualitative and quantitative experimental results, we show promising potentials of statistical approaches for human behavior research.

Vestibulo-Cervico-Ocular Responses and Tracking Eye Movements after Prolonged Exposure to Microgravity

NASA Technical Reports Server (NTRS)

Kornilova, L. N.; Naumov, I. A.; Azarov, K. A.; Sagalovitch, S. V.; Reschke, Millard F.; Kozlovskaya, I. B.

2007-01-01

The vestibular function and tracking eye movements were investigated in 12 Russian crew members of ISS missions on days 1(2), 4(5-6), and 8(9-10) after prolonged exposure to microgravity (126 to 195 days). The spontaneous oculomotor activity, static torsional otolith-cervico-ocular reflex, dynamic vestibulo-cervico-ocular responses, vestibular reactivity, tracking eye movements, and gaze-holding were studied using videooculography (VOG) and electrooculography (EOG) for parallel eye movement recording. On post-flight days 1-2 (R+1-2) some cosmonauts demonstrated: - an increased spontaneous oculomotor activity (floating eye movements, spontaneous nystagmus of the typical and atypical form, square wave jerks, gaze nystagmus) with the head held in the vertical position; - suppressed otolith function (absent or reduced by one half amplitude of torsional compensatory eye counter-rolling) with the head inclined statically right- or leftward by 300; - increased vestibular reactivity (lowered threshold and increased intensity of the vestibular nystagmus) during head turns around the longitudinal body axis at 0.125 Hz; - a significant change in the accuracy, velocity, and temporal characteristics of the eye tracking. The pattern, depth, dynamics, and velocity of the vestibular function and tracking eye movements recovery varied with individual participants in the investigation. However, there were also regular responses during readaptation to the normal gravity: - suppression of the otolith function was typically accompanied by an exaggerated vestibular reactivity; - the structure of visual tracking (the accuracy of fixational eye rotations, smooth tracking, and gaze-holding) was disturbed (the appearance of correcting saccades, the transition of smooth tracking to saccadic tracking) only in those cosmonauts who, in parallel to an increased reactivity of the vestibular input, also had central changes in the oculomotor system (spontaneous nystagmus, gaze nystagmus).

Distractor interference during smooth pursuit eye movements.

PubMed

Spering, Miriam; Gegenfurtner, Karl R; Kerzel, Dirk

2006-10-01

When 2 targets for pursuit eye movements move in different directions, the eye velocity follows the vector average (S. G. Lisberger & V. P. Ferrera, 1997). The present study investigates the mechanisms of target selection when observers are instructed to follow a predefined horizontal target and to ignore a moving distractor stimulus. Results show that at 140 ms after distractor onset, horizontal eye velocity is decreased by about 25%. Vertical eye velocity increases or decreases by 1 degrees /s in the direction opposite from the distractor. This deviation varies in size with distractor direction, velocity, and contrast. The effect was present during the initiation and steady-state tracking phase of pursuit but only when the observer had prior information about target motion. Neither vector averaging nor winner-take-all models could predict the response to a moving to-be-ignored distractor during steady-state tracking of a predefined target. The contributions of perceptual mislocalization and spatial attention to the vertical deviation in pursuit are discussed. Copyright 2006 APA.

The Role of Eye Movement Desensitization and Reprocessing (EMDR) Therapy in Medicine: Addressing the Psychological and Physical Symptoms Stemming from Adverse Life Experiences

PubMed Central

Shapiro, Francine

2014-01-01

Background: A substantial body of research shows that adverse life experiences contribute to both psychological and biomedical pathology. Eye movement desensitization and reprocessing (EMDR) therapy is an empirically validated treatment for trauma, including such negative life experiences as commonly present in medical practice. The positive therapeutic outcomes rapidly achieved without homework or detailed description of the disturbing event offer the medical community an efficient treatment approach with a wide range of applications. Methods: All randomized studies and significant clinical reports related to EMDR therapy for treating the experiential basis of both psychological and somatic disorders are reviewed. Also reviewed are the recent studies evaluating the eye movement component of the therapy, which has been posited to contribute to the rapid improvement attributable to EMDR treatment. Results: Twenty-four randomized controlled trials support the positive effects of EMDR therapy in the treatment of emotional trauma and other adverse life experiences relevant to clinical practice. Seven of 10 studies reported EMDR therapy to be more rapid and/or more effective than trauma-focused cognitive behavioral therapy. Twelve randomized studies of the eye movement component noted rapid decreases in negative emotions and/or vividness of disturbing images, with an additional 8 reporting a variety of other memory effects. Numerous other evaluations document that EMDR therapy provides relief from a variety of somatic complaints. Conclusion: EMDR therapy provides physicians and other clinicians with an efficient approach to address psychological and physiologic symptoms stemming from adverse life experiences. Clinicians should therefore evaluate patients for experiential contributors to clinical manifestations. PMID:24626074

Geometry and Gesture-Based Features from Saccadic Eye-Movement as a Biometric in Radiology

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hammond, Tracy; Tourassi, Georgia; Yoon, Hong-Jun

In this study, we present a novel application of sketch gesture recognition on eye-movement for biometric identification and estimating task expertise. The study was performed for the task of mammographic screening with simultaneous viewing of four coordinated breast views as typically done in clinical practice. Eye-tracking data and diagnostic decisions collected for 100 mammographic cases (25 normal, 25 benign, 50 malignant) and 10 readers (three board certified radiologists and seven radiology residents), formed the corpus for this study. Sketch gesture recognition techniques were employed to extract geometric and gesture-based features from saccadic eye-movements. Our results show that saccadic eye-movement, characterizedmore » using sketch-based features, result in more accurate models for predicting individual identity and level of expertise than more traditional eye-tracking features.« less

Automatic removal of eye-movement and blink artifacts from EEG signals.

PubMed

Gao, Jun Feng; Yang, Yong; Lin, Pan; Wang, Pei; Zheng, Chong Xun

2010-03-01

Frequent occurrence of electrooculography (EOG) artifacts leads to serious problems in interpreting and analyzing the electroencephalogram (EEG). In this paper, a robust method is presented to automatically eliminate eye-movement and eye-blink artifacts from EEG signals. Independent Component Analysis (ICA) is used to decompose EEG signals into independent components. Moreover, the features of topographies and power spectral densities of those components are extracted to identify eye-movement artifact components, and a support vector machine (SVM) classifier is adopted because it has higher performance than several other classifiers. The classification results show that feature-extraction methods are unsuitable for identifying eye-blink artifact components, and then a novel peak detection algorithm of independent component (PDAIC) is proposed to identify eye-blink artifact components. Finally, the artifact removal method proposed here is evaluated by the comparisons of EEG data before and after artifact removal. The results indicate that the method proposed could remove EOG artifacts effectively from EEG signals with little distortion of the underlying brain signals.

Validity of Eye Movement Methods and Indices for Capturing Semantic (Associative) Priming Effects

ERIC Educational Resources Information Center

Odekar, Anshula; Hallowell, Brooke; Kruse, Hans; Moates, Danny; Lee, Chao-Yang

2009-01-01

Purpose: The purpose of this investigation was to evaluate the usefulness of eye movement methods and indices as a tool for studying priming effects by verifying whether eye movement indices capture semantic (associative) priming effects in a visual cross-format (written word to semantically related picture) priming paradigm. Method: In the…

Learning to See: Guiding Students' Attention via a Model's Eye Movements Fosters Learning

ERIC Educational Resources Information Center

Jarodzka, Halszka; van Gog, Tamara; Dorr, Michael; Scheiter, Katharina; Gerjets, Peter

2013-01-01

This study investigated how to teach perceptual tasks, that is, classifying fish locomotion, through eye movement modeling examples (EMME). EMME consisted of a replay of eye movements of a didactically behaving domain expert (model), which had been recorded while he executed the task, superimposed onto the video stimulus. Seventy-five students…

Eye Movements of Patients with Tunnel Vision while Walking

PubMed Central

Vargas-Martín, Fernando; Peli, Eli

2006-01-01

Purpose To determine how severe peripheral field loss (PFL) affects the dispersion of eye movements relative to the head, while walking in real environments. This information should help to better define the visual field and clearance requirements for head-mounted mobility visual aids. Methods Eye positions relative to the head were recorded in five retinitis pigmentosa patients with less than 15° of visual field and three normally-sighted people, each walking in varied environments for more than 30 minutes. The eye position recorder was made portable by modifying a head-mounted ISCAN system. Custom data processing was implemented to reject unreliable data. Sample standard deviations of eye position (dispersion) were compared across subject groups and environments. Results PFL patients exhibited narrower horizontal eye position dispersions than normally-sighted subjects (9.4° vs. 14.2°, p < 0.0001) and PFL patients’ vertical dispersions were smaller when walking indoors than outdoors (8.2° vs. 10.3°, p = 0.048). Conclusions When walking, the PFL patients did not increase their scanning eye movements to compensate for missing peripheral vision information. Their horizontal scanning was actually reduced, possibly because saccadic amplitude is limited by a lack of peripheral stimulation. The results suggest that a field-of-view as wide as 40° may be needed for closed (immersive) head-mounted mobility aids, while a much narrower display, perhaps as narrow as 20°, might be sufficient with an open design. PMID:17122116

Investigating the causes of wrap-up effects: evidence from eye movements and E-Z Reader.

PubMed

Warren, Tessa; White, Sarah J; Reichle, Erik D

2009-04-01

Wrap-up effects in reading have traditionally been thought to reflect increased processing associated with intra- and inter-clause integration (Just, M. A. & Carpenter, P. A. (1980). A theory of reading: From eye fixations to comprehension. Psychological Review,87(4), 329-354; Rayner, K., Kambe, G., & Duffy, S. A. (2000). The effect of clause wrap-up on eye movements during reading. The Quarterly Journal of Experimental Psychology,53A(4), 1061-1080; cf. Hirotani, M., Frazier, L., & Rayner, K. (2006). Punctuation and intonation effects on clause and sentence wrap-up: Evidence from eye movements. Journal of Memory and Language,54, 425-443). We report an eye-tracking experiment with a strong manipulation of integrative complexity at a critical word that was either sentence-final, ended a comma-marked clause, or was not comma-marked. Although both complexity and punctuation had reliable effects, they did not interact in any eye-movement measure. These results as well as simulations using the E-Z Reader model of eye-movement control (Reichle, E. D., Warren, T., & McConnell, K. (2009). Using E-Z Reader to model the effects of higher-level language processing on eye movements during reading. Psychonomic Bulletin & Review,16(1), 1-20) suggest that traditional accounts of clause wrap-up are incomplete.

Eye Movement Correlates of Acquired Central Dyslexia

ERIC Educational Resources Information Center

Schattka, Kerstin I.; Radach, Ralph; Huber, Walter

2010-01-01

Based on recent progress in theory and measurement techniques, the analysis of eye movements has become one of the major methodological tools in experimental reading research. Our work uses this approach to advance the understanding of impaired information processing in acquired central dyslexia of stroke patients with aphasia. Up to now there has…

Adapted head- and eye-movement responses to added-head inertia

NASA Technical Reports Server (NTRS)

Gauthier, G. M.; Martin, B. J.; Stark, L. W.

1986-01-01

Adaptation to inertia added to the head was studied in men by mounting masses on a rigidly attached helmet until two- to ten-fold increases of inertia were produced, while an overhead suspension compensated for the weights. The observed changes in the eye and head movement coordination included increased head movement latencies, as well as changes in the eye movement amplitude, and later stabilizing alternate contractions of the neck muscles. Oscillopsia, or continual displacement or instability of the visual world, which is a symptom of a breakdown of space constancy, was prominent and consistent in the perceptual reports of the subjects. Although adaptation resulting from adding inertia to the head occurred much faster than that induced by adding prisms or lenses, it has similar perceptual and motor components that may be objectively studied in detail.

Eye-Pursuit and Reafferent Head Movement Signals Carried by Pursuit Neurons in the Caudal Part of the Frontal Eye Fields during Head-Free Pursuit

PubMed Central

Kasahara, Satoshi; Akao, Teppei; Kurkin, Sergei; Peterson, Barry W.

2009-01-01

Eye and head movements are coordinated during head-free pursuit. To examine whether pursuit neurons in frontal eye fields (FEF) carry gaze-pursuit commands that drive both eye-pursuit and head-pursuit, monkeys whose heads were free to rotate about a vertical axis were trained to pursue a juice feeder with their head and a target with their eyes. Initially the feeder and target moved synchronously with the same visual angle. FEF neurons responding to this gaze-pursuit were tested for eye-pursuit of target motion while the feeder was stationary and for head-pursuit while the target was stationary. The majority of pursuit neurons exhibited modulation during head-pursuit, but their preferred directions during eye-pursuit and head-pursuit were different. Although peak modulation occurred during head movements, the onset of discharge usually was not aligned with the head movement onset. The minority of neurons whose discharge onset was so aligned discharged after the head movement onset. These results do not support the idea that the head-pursuit–related modulation reflects head-pursuit commands. Furthermore, modulation similar to that during head-pursuit was obtained by passive head rotation on stationary trunk. Our results suggest that FEF pursuit neurons issue gaze or eye movement commands during gaze-pursuit and that the head-pursuit–related modulation primarily reflects reafferent signals resulting from head movements. PMID:18483002

Influence of Eye Movements, Auditory Perception, and Phonemic Awareness in the Reading Process

ERIC Educational Resources Information Center

Megino-Elvira, Laura; Martín-Lobo, Pilar; Vergara-Moragues, Esperanza

2016-01-01

The authors' aim was to analyze the relationship of eye movements, auditory perception, and phonemic awareness with the reading process. The instruments used were the King-Devick Test (saccade eye movements), the PAF test (auditory perception), the PFC (phonemic awareness), the PROLEC-R (lexical process), the Canals reading speed test, and the…

Secondary-Task Effects on Learning with Multimedia: An Investigation through Eye-Movement Analysis

ERIC Educational Resources Information Center

Acarturk, Cengiz; Ozcelik, Erol

2017-01-01

This study investigates secondary-task interference on eye movements through learning with multimedia. We focus on the relationship between the influence of the secondary task on the eye movements of learners, and the learning outcomes as measured by retention, matching, and transfer. Half of the participants performed a spatial tapping task while…

A Link Between Attentional Function, Effective Eye Movements, and Driving Ability

PubMed Central

2016-01-01

The misallocation of driver visual attention has been suggested as a major contributing factor to vehicle accidents. One possible reason is that the relatively high cognitive demands of driving limit the ability to efficiently allocate gaze. We present an experiment that explores the relationship between attentional function and visual performance when driving. Drivers performed 2 variations of a multiple-object tracking task targeting aspects of cognition including sustained attention, dual-tasking, covert attention, and visuomotor skill. They also drove a number of courses in a driving simulator. Eye movements were recorded throughout. We found that individuals who performed better in the cognitive tasks exhibited more effective eye movement strategies when driving, such as scanning more of the road, and they also exhibited better driving performance. We discuss the potential link between an individual’s attentional function, effective eye movements, and driving ability. We also discuss the use of a visuomotor task in assessing driving behavior. PMID:27893270

Saccadic eye movements as a measure of residual effects: temazepam compared with other hypnotics.

PubMed

Hofferberth, B; Hirschberg; Grotemeyer

1986-01-01

Eye movements are classified into two categories: quickly running saccades and smooth pursuit movements. Saccades are fast conjugate eye movements with a preprogrammed direction, amplitude, and speed course; their purpose is to register new objects in the visual field. The duration and velocity of saccadic eye movements are very much dependent on vigilance. Comparisons were made with a number of psychometric tests [d 2 Durchstreichtest (cross out test), Viennese determination apparatus, and flicker fusion frequency] and the velocity of fast eye movements. The results of three separate investigations are presented. Standardization was undertaken in 100 healthy volunteers, 50 male and 50 female subjects aged between 20 and more than 50 years were included. In an open parallel group study, comparisons were made between various hypnotics with different half-lives (temazepam, flunitrazepam, flurazepam, and phenobarbital). There were 10 healthy volunteers in each group, and medication was taken as a single night-time dose for 7 nights. In a double-blind study, temazepam (20 mg/day) was tested against flunitrazepam (2 mg/day). Dosing lasted 7 days. A marked impairment of the saccadic eye movements was observed with flunitrazepam but not with temazepam. Of all the benzodiazepines tested, only temazepam had no influence on the parameters of the saccade test. These results can be explained by temazepam's short half-life and also by the fact that no active metabolites are formed.

The Relation between Reading Skills and Eye Movement Patterns in Adolescent Readers: Evidence from a Regular Orthography

PubMed Central

Krieber, Magdalena; Bartl-Pokorny, Katrin D.; Pokorny, Florian B.; Einspieler, Christa; Langmann, Andrea; Körner, Christof; Falck-Ytter, Terje; Marschik, Peter B.

2016-01-01

Over the past decades, the relation between reading skills and eye movement behavior has been well documented in English-speaking cohorts. As English and German differ substantially with regard to orthographic complexity (i.e. grapheme-phoneme correspondence), we aimed to delineate specific characteristics of how reading speed and reading comprehension interact with eye movements in typically developing German-speaking (Austrian) adolescents. Eye movements of 22 participants (14 females; mean age = 13;6 years;months) were tracked while they were performing three tasks, namely silently reading words, texts, and pseudowords. Their reading skills were determined by means of a standardized German reading speed and reading comprehension assessment (Lesegeschwindigkeits- und -verständnistest für Klassen 6−12). We found that (a) reading skills were associated with various eye movement parameters in each of the three reading tasks; (b) better reading skills were associated with an increased efficiency of eye movements, but were primarily linked to spatial reading parameters, such as the number of fixations per word, the total number of saccades and saccadic amplitudes; (c) reading speed was a more reliable predictor for eye movement parameters than reading comprehension; (d) eye movements were highly correlated across reading tasks, which indicates consistent reading performances. Contrary to findings in English-speaking cohorts, the reading skills neither consistently correlated with temporal eye movement parameters nor with the number or percentage of regressions made while performing any of the three reading tasks. These results indicate that, although reading skills are associated with eye movement patterns irrespective of language, the temporal and spatial characteristics of this association may vary with orthographic consistency. PMID:26727255

Eye movements in interception with delayed visual feedback.

PubMed

Cámara, Clara; de la Malla, Cristina; López-Moliner, Joan; Brenner, Eli

2018-07-01

The increased reliance on electronic devices such as smartphones in our everyday life exposes us to various delays between our actions and their consequences. Whereas it is known that people can adapt to such delays, the mechanisms underlying such adaptation remain unclear. To better understand these mechanisms, the current study explored the role of eye movements in interception with delayed visual feedback. In two experiments, eye movements were recorded as participants tried to intercept a moving target with their unseen finger while receiving delayed visual feedback about their own movement. In Experiment 1, the target randomly moved in one of two different directions at one of two different velocities. The delay between the participant's finger movement and movement of the cursor that provided feedback about the finger movements was gradually increased. Despite the delay, participants followed the target with their gaze. They were quite successful at hitting the target with the cursor. Thus, they moved their finger to a position that was ahead of where they were looking. Removing the feedback showed that participants had adapted to the delay. In Experiment 2, the target always moved in the same direction and at the same velocity, while the cursor's delay varied across trials. Participants still always directed their gaze at the target. They adjusted their movement to the delay on each trial, often succeeding to intercept the target with the cursor. Since their gaze was always directed at the target, and they could not know the delay until the cursor started moving, participants must have been using peripheral vision of the delayed cursor to guide it to the target. Thus, people deal with delays by directing their gaze at the target and using both experience from previous trials (Experiment 1) and peripheral visual information (Experiment 2) to guide their finger in a way that will make the cursor hit the target.

Are smooth pursuit eye movements altered in chronic whiplash-associated disorders? A cross-sectional study.

PubMed

Kongsted, A; Jørgensen, L V; Bendix, T; Korsholm, L; Leboeuf-Yde, C

2007-11-01

To evaluate whether smooth pursuit eye movements differed between patients with long-lasting whiplash-associated disorders and controls when using a purely computerized method for the eye movement analysis. Cross-sectional study comparing patients with whiplash-associated disorders and controls who had not been exposed to head or neck trauma and had no notable neck complaints. Smooth pursuit eye movements were registered while the subjects were seated with and without rotated cervical spine. Thirty-four patients with whiplash-associated disorders with symptoms more than six months after a car collision and 60 controls. Smooth pursuit eye movements were almost identical in patients with chronic whiplash-associated disorders and controls, both when the neck was rotated and in the neutral position. Disturbed smooth pursuit eye movements do not appear to be a distinct feature in patients with chronic whiplash-associated disorders. This is in contrast to results of previous studies and may be due to the fact that analyses were performed in a computerized and objective manner. Other possible reasons for the discrepancy to previous studies are discussed.

Diurnal variation of eye movement and heart rate variability in the human fetus at term.

PubMed

Morokuma, S; Horimoto, N; Satoh, S; Nakano, H

2001-07-01

To elucidate diurnal variations in eye movement and fetal heart rate (FHR) variability in the term fetus, we observed these two parameters continuously for 24 h, using real-time ultrasound and Doppler cardiotocograph, respectively. Studied were five uncomplicated fetuses at term. The time series data of the presence and absence of eye movement and mean FHR value for each 1 min were analyzed using the maximum entropy method (MEM) and subsequent nonlinear least squares fitting. According to the power value of eye movement, all five cases were classified into two groups: three cases in the large power group and two cases in the small power group. The acrophases of eye movement and FHR variability in the large power group were close, thereby implying the existence of a diurnal rhythm in both these parameters and also that they are synchronized. In the small power group, the acrophases were separated. The synchronization of eye movement and FHR variability in the large power group suggests that these phenomena are governed by a common central mechanism related to diurnal rhythm generation.

Opening a Window into Reading Development: Eye Movements' Role Within a Broader Literacy Research Framework.

PubMed

Miller, Brett; O'Donnell, Carol

2013-01-01

The cumulative body of eye movement research provides significant insight into how readers process text. The heart of this work spans roughly 40 years reflecting the maturity of both the topics under study and experimental approaches used to investigate reading. Recent technological advancements offer increased flexibility to the field providing the potential to more concertedly study reading and literacy from an individual differences perspective. Historically, eye movement research focused far less on developmental issues related to individual differences in reading; however, this issue and the broader change it represents signal a meaningful transition inclusive of individual differences. The six papers in this special issue signify the recent, increased attention to and recognition of eye movement research's transition to emphasize individual differences in reading while appreciating early contributions (e.g., Rayner, 1986) in this direction. We introduce these six papers and provide some historical context for the use of eye movement methodology to examine reading and context for the eye movement field's early transition to examining individual differences, culminating in future research recommendations.

Contrasting expressions of aggressive behavior released by lesions of the central nucleus of the amygdala during wakefulness and rapid eye movement sleep without atonia in cats.

PubMed

Zagrodzka, J; Hedberg, C E; Mann, G L; Morrison, A R

1998-06-01

Whether damage to the central nucleus of the amygdala (Ace) contributes to the predatorylike attack sometimes observed in rapid eye movement sleep without atonia (REM-A), created in cats by bilateral pontine lesions, was examined. Such lesions eliminate REM sleep skeletal muscle atonia and release elaborate behavior. Unilateral damage to the Ace alone increased affective defensive aggressive behavior toward humans and conspecifics without altering predatory behavior in wakefulness. Pontine lesions added at loci normally not leading to aggression induced predatorylike attacks in REM-A as well as the waking affective defense. Alterations of autonomic activity, the absence of relevant environmental stimuli in REM-A, or both may explain the state-related differences.

Lévy-like diffusion in eye movements during spoken-language comprehension.

PubMed

Stephen, Damian G; Mirman, Daniel; Magnuson, James S; Dixon, James A

2009-05-01

This study explores the diffusive properties of human eye movements during a language comprehension task. In this task, adults are given auditory instructions to locate named objects on a computer screen. Although it has been convention to model visual search as standard Brownian diffusion, we find evidence that eye movements are hyperdiffusive. Specifically, we use comparisons of maximum-likelihood fit as well as standard deviation analysis and diffusion entropy analysis to show that visual search during language comprehension exhibits Lévy-like rather than Gaussian diffusion.

Lévy-like diffusion in eye movements during spoken-language comprehension

NASA Astrophysics Data System (ADS)

Stephen, Damian G.; Mirman, Daniel; Magnuson, James S.; Dixon, James A.

2009-05-01

This study explores the diffusive properties of human eye movements during a language comprehension task. In this task, adults are given auditory instructions to locate named objects on a computer screen. Although it has been convention to model visual search as standard Brownian diffusion, we find evidence that eye movements are hyperdiffusive. Specifically, we use comparisons of maximum-likelihood fit as well as standard deviation analysis and diffusion entropy analysis to show that visual search during language comprehension exhibits Lévy-like rather than Gaussian diffusion.

Saccadic Eye Movements in Anorexia Nervosa

PubMed Central

Phillipou, Andrea; Rossell, Susan Lee; Gurvich, Caroline; Hughes, Matthew Edward; Castle, David Jonathan; Nibbs, Richard Grant; Abel, Larry Allen

2016-01-01

Background Anorexia Nervosa (AN) has a mortality rate among the highest of any mental illness, though the factors involved in the condition remain unclear. Recently, the potential neurobiological underpinnings of the condition have become of increasing interest. Saccadic eye movement tasks have proven useful in our understanding of the neurobiology of some other psychiatric illnesses as they utilise known brain regions, but to date have not been examined in AN. The aim of this study was to investigate whether individuals with AN differ from healthy individuals in performance on a range of saccadic eye movements tasks. Methods 24 females with AN and 25 healthy individuals matched for age, gender and premorbid intelligence participated in the study. Participants were required to undergo memory-guided and self-paced saccade tasks, and an interleaved prosaccade/antisaccade/no-go saccade task while undergoing functional magnetic resonance imaging (fMRI). Results AN participants were found to make prosaccades of significantly shorter latency than healthy controls. AN participants also made an increased number of inhibitory errors on the memory-guided saccade task. Groups did not significantly differ in antisaccade, no-go saccade or self-paced saccade performance, or fMRI findings. Discussion The results suggest a potential role of GABA in the superior colliculus in the psychopathology of AN. PMID:27010196

The Neural Basis of Smooth Pursuit Eye Movements in the Rhesus Monkey Brain

ERIC Educational Resources Information Center

Ilg, Uwe J.; Thier, Peter

2008-01-01

Smooth pursuit eye movements are performed in order to prevent retinal image blur of a moving object. Rhesus monkeys are able to perform smooth pursuit eye movements quite similar as humans, even if the pursuit target does not consist in a simple moving dot. Therefore, the study of the neuronal responses as well as the consequences of…

Evaluating and Reporting Data Quality in Eye Movement Research. Technical Report No. 193.

ERIC Educational Resources Information Center

McConkie, George W.

Stressing that it is necessary to have information about the quality of eye movement data in order to judge the degree of confidence one should have in the results of an experiment using eye movement records as data, this report suggests ways for assessing and reporting such information. Specifically, the report deals with three areas: (1)…

Computational Model-Based Prediction of Human Episodic Memory Performance Based on Eye Movements

NASA Astrophysics Data System (ADS)

Sato, Naoyuki; Yamaguchi, Yoko

Subjects' episodic memory performance is not simply reflected by eye movements. We use a ‘theta phase coding’ model of the hippocampus to predict subjects' memory performance from their eye movements. Results demonstrate the ability of the model to predict subjects' memory performance. These studies provide a novel approach to computational modeling in the human-machine interface.

A common control signal and a ballistic stage can explain the control of coordinated eye-hand movements.

PubMed

Gopal, Atul; Murthy, Aditya

2016-06-01

Voluntary control has been extensively studied in the context of eye and hand movements made in isolation, yet little is known about the nature of control during eye-hand coordination. We probed this with a redirect task. Here subjects had to make reaching/pointing movements accompanied by coordinated eye movements but had to change their plans when the target occasionally changed its position during some trials. Using a race model framework, we found that separate effector-specific mechanisms may be recruited to control eye and hand movements when executed in isolation but when the same effectors are coordinated a unitary mechanism to control coordinated eye-hand movements is employed. Specifically, we found that performance curves were distinct for the eye and hand when these movements were executed in isolation but were comparable when they were executed together. Second, the time to switch motor plans, called the target step reaction time, was different in the eye-alone and hand-alone conditions but was similar in the coordinated condition under assumption of a ballistic stage of ∼40 ms, on average. Interestingly, the existence of this ballistic stage could predict the extent of eye-hand dissociations seen in individual subjects. Finally, when subjects were explicitly instructed to control specifically a single effector (eye or hand), redirecting one effector had a strong effect on the performance of the other effector. Taken together, these results suggest that a common control signal and a ballistic stage are recruited when coordinated eye-hand movement plans require alteration. Copyright © 2016 the American Physiological Society.

A common control signal and a ballistic stage can explain the control of coordinated eye-hand movements

PubMed Central

Gopal, Atul

2016-01-01

Voluntary control has been extensively studied in the context of eye and hand movements made in isolation, yet little is known about the nature of control during eye-hand coordination. We probed this with a redirect task. Here subjects had to make reaching/pointing movements accompanied by coordinated eye movements but had to change their plans when the target occasionally changed its position during some trials. Using a race model framework, we found that separate effector-specific mechanisms may be recruited to control eye and hand movements when executed in isolation but when the same effectors are coordinated a unitary mechanism to control coordinated eye-hand movements is employed. Specifically, we found that performance curves were distinct for the eye and hand when these movements were executed in isolation but were comparable when they were executed together. Second, the time to switch motor plans, called the target step reaction time, was different in the eye-alone and hand-alone conditions but was similar in the coordinated condition under assumption of a ballistic stage of ∼40 ms, on average. Interestingly, the existence of this ballistic stage could predict the extent of eye-hand dissociations seen in individual subjects. Finally, when subjects were explicitly instructed to control specifically a single effector (eye or hand), redirecting one effector had a strong effect on the performance of the other effector. Taken together, these results suggest that a common control signal and a ballistic stage are recruited when coordinated eye-hand movement plans require alteration. PMID:26888104

Eye movement related brain responses to emotional scenes during free viewing

PubMed Central

Simola, Jaana; Torniainen, Jari; Moisala, Mona; Kivikangas, Markus; Krause, Christina M.

2013-01-01

Emotional stimuli are preferentially processed over neutral stimuli. Previous studies, however, disagree on whether emotional stimuli capture attention preattentively or whether the processing advantage is dependent on allocation of attention. The present study investigated attention and emotion processes by measuring brain responses related to eye movement events while 11 participants viewed images selected from the International Affective Picture System (IAPS). Brain responses to emotional stimuli were compared between serial and parallel presentation. An “emotional” set included one image with high positive or negative valence among neutral images. A “neutral” set comprised four neutral images. The participants were asked to indicate which picture—if any—was emotional and to rate that picture on valence and arousal. In the serial condition, the event-related potentials (ERPs) were time-locked to the stimulus onset. In the parallel condition, the ERPs were time-locked to the first eye entry on an image. The eye movement results showed facilitated processing of emotional, especially unpleasant information. The EEG results in both presentation conditions showed that the LPP (“late positive potential”) amplitudes at 400–500 ms were enlarged for the unpleasant and pleasant pictures as compared to neutral pictures. Moreover, the unpleasant scenes elicited stronger responses than pleasant scenes. The ERP results did not support parafoveal emotional processing, although the eye movement results suggested faster attention capture by emotional stimuli. Our findings, thus, suggested that emotional processing depends on overt attentional resources engaged in the processing of emotional content. The results also indicate that brain responses to emotional images can be analyzed time-locked to eye movement events, although the response amplitudes were larger during serial presentation. PMID:23970856

Eye movements during the Rorschach test in schizophrenia.

PubMed

Hori, Yasuko; Fukuzako, Hiroshi; Sugimoto, Yoko; Takigawa, Morikuni

2002-08-01

In order to understand relationships between scanning behaviors, characteristics of visual stimuli and the clinical symptoms in schizophrenia, eye movements of 37 schizophrenic patients and 36 controls were recorded using an eye-mark recorder during a free-response period in a Rorschach test. Four cards (I, II, V and VIII) were used. Data were analyzed during 15 s from the presentation of each card. For all cards, the number of eye fixations and the number of eye fixation areas were fewer, and total scanning length and mean scanning length were shorter for schizophrenic patients than for controls. For card II, in the non-popular response group, eye fixation frequency upon area 5 + 6 (red) was higher for schizophrenic patients. For card VIII, in the popular response group, eye fixation frequency upon area 5 + 6 (pink) was lower for schizophrenic patients. For cards II and VIII, the number of eye fixations was inversely correlated with negative symptoms. For card II, total scanning length tended to be inversely correlated with negative symptoms, and mean eye fixation time was correlated with negative symptoms. The number of eye fixation areas was inversely correlated with positive symptoms. For card VIII, eye fixation frequency in a stimulative area tended to be correlated with positive symptoms. Scanning behaviors in schizophrenic patients are affected by characteristics of visual stimuli, and partially by clinical symptoms.

Application of eye movement measuring system OBER 2 to medicine and technology

NASA Astrophysics Data System (ADS)

Ober, Jozef; Hajda, Janusz; Loska, Jacek; Jamicki, Michal

1997-08-01

The OBER 2 is an infrared light eye movement measuring system and it works with IBM PC compatible computers. As one of the safest systems for measuring of eye movement it uses a very short period of infrared light flashing time (80 microsecond for each measure point). System has an advanced analog-digital controller, which includes background suppression and prediction mechanisms guaranteeing elimination of slow changes and fluctuations of external illumination frequency up to 100 Hz, with effectiveness better than 40 dB. Setting from PC the active measure axis, sampling rate (25 - 4000 Hz) and making start and stop the measure, make it possible to control the outside environment in real-time. By proper controlling of gain it is possible to get high time and position resolution of 0.5 minute of arc even for big amplitude of eye movement (plus or minus 20 degree of visual angle). The whole communication system can also be driven directly by eye movement in real time. The possibility of automatic selection of the most essential elements of eye movement, individual for each person and those that take place for each person in determined situations of life independently from personal features, is a key to practical application. Hence one of conducted research topic is a personal identification based on personal features. Another task is a research project of falling asleep detection, which can be applied to warn the drivers before falling asleep while driving. This measuring system with a proper expert system can also be used to detect a dyslexia and other disabilities of the optic system.

Eye-Movement Patterns Are Associated with Communicative Competence in Autistic Spectrum Disorders

ERIC Educational Resources Information Center

Norbury, Courtenay Frazier; Brock, Jon; Cragg, Lucy; Einav, Shiri; Griffiths, Helen; Nation, Kate

2009-01-01

Background: Investigations using eye-tracking have reported reduced fixations to salient social cues such as eyes when participants with autism spectrum disorders (ASD) view social scenes. However, these studies have not distinguished different cognitive phenotypes. Methods: The eye-movements of 28 teenagers with ASD and 18 typically developing…

Improving Silent Reading Performance through Feedback on Eye Movements: A Feasibility Study

ERIC Educational Resources Information Center

Korinth, Sebastian P.; Fiebach, Christian J.

2018-01-01

This feasibility study investigated if feedback about individual eye movements, reflecting varying word processing stages, can improve reading performance. Twenty-five university students read 90 newspaper articles during 9 eye-tracking sessions. Training group participants (n = 12) were individually briefed before each session, which eye movement…

Tracking the Eye Movement of Four Years Old Children Learning Chinese Words.

PubMed

Lin, Dan; Chen, Guangyao; Liu, Yingyi; Liu, Jiaxin; Pan, Jue; Mo, Lei

2018-02-01

Storybook reading is the major source of literacy exposure for beginning readers. The present study tracked 4-year-old Chinese children's eye movements while they were reading simulated storybook pages. Their eye-movement patterns were examined in relation to their word learning gains. The same reading list, consisting of 20 two-character Chinese words, was used in the pretest, 5-min eye-tracking learning session, and posttest. Additionally, visual spatial skill and phonological awareness were assessed in the pretest as cognitive controls. The results showed that the children's attention was attracted quickly by pictures, on which their attention was focused most, with only 13% of the time looking at words. Moreover, significant learning gains in word reading were observed, from the pretest to posttest, from 5-min exposure to simulated storybook pages with words, picture and pronunciation of two-character words present. Furthermore, the children's attention to words significantly predicted posttest reading beyond socioeconomic status, age, visual spatial skill, phonological awareness and pretest reading performance. This eye-movement evidence of storybook reading by children as young as four years, reading a non-alphabetic script (i.e., Chinese), has demonstrated exciting findings that children can learn words effectively with minimal exposure and little instruction; these findings suggest that learning to read requires attention to the basic words itself. The study contributes to our understanding of early reading acquisition with eye-movement evidence from beginning readers.

Eye movements of patients with tunnel vision while walking.

PubMed

Vargas-Martín, Fernando; Peli, Eli

2006-12-01

To determine how severe peripheral field loss (PFL) affects the dispersion of eye movements relative to the head in patients walking in real environments. This information should help to define the visual field and clearance requirements for head-mounted mobility visual aids. Eye positions relative to the head were recorded in five patients with retinitis pigmentosa who had less than 15 degrees of visual field and in three normally sighted people, each walking in varied environments for more than 30 minutes. The eye-position recorder was made portable by modifying a head-mounted system (ISCAN, Burlington, MA). Custom data processing was implemented, to reject unreliable data. Sample standard deviations of eye position (dispersion) were compared across subject groups and environments. The patients with PFL exhibited narrower horizontal eye-position dispersions than did the normally sighted subjects (9.4 degrees vs. 14.2 degrees , P < 0.0001), and the vertical dispersions of patients with PFL were smaller when they were walking indoors than when walking outdoors (8.2 degrees vs. 10.3 degrees ; P = 0.048). When walking, the patients with PFL did not increase their scanning eye movements to compensate for missing peripheral vision information. Their horizontal scanning was actually reduced, possibly because of lack of peripheral stimulation. The results suggest that a field of view as wide as 40 degrees may be needed for closed (immersive) head-mounted mobility aids, whereas a much narrower display, perhaps as narrow as 20 degrees , may be sufficient with an open design.

fMRI evidence for sensorimotor transformations in human cortex during smooth pursuit eye movements.

PubMed

Kimmig, H; Ohlendorf, S; Speck, O; Sprenger, A; Rutschmann, R M; Haller, S; Greenlee, M W

2008-01-01

Smooth pursuit eye movements (SP) are driven by moving objects. The pursuit system processes the visual input signals and transforms this information into an oculomotor output signal. Despite the object's movement on the retina and the eyes' movement in the head, we are able to locate the object in space implying coordinate transformations from retinal to head and space coordinates. To test for the visual and oculomotor components of SP and the possible transformation sites, we investigated three experimental conditions: (I) fixation of a stationary target with a second target moving across the retina (visual), (II) pursuit of the moving target with the second target moving in phase (oculomotor), (III) pursuit of the moving target with the second target remaining stationary (visuo-oculomotor). Precise eye movement data were simultaneously measured with the fMRI data. Visual components of activation during SP were located in the motion-sensitive, temporo-parieto-occipital region MT+ and the right posterior parietal cortex (PPC). Motor components comprised more widespread activation in these regions and additional activations in the frontal and supplementary eye fields (FEF, SEF), the cingulate gyrus and precuneus. The combined visuo-oculomotor stimulus revealed additional activation in the putamen. Possible transformation sites were found in MT+ and PPC. The MT+ activation evoked by the motion of a single visual dot was very localized, while the activation of the same single dot motion driving the eye was rather extended across MT+. The eye movement information appeared to be dispersed across the visual map of MT+. This could be interpreted as a transfer of the one-dimensional eye movement information into the two-dimensional visual map. Potentially, the dispersed information could be used to remap MT+ to space coordinates rather than retinal coordinates and to provide the basis for a motor output control. A similar interpretation holds for our results in the PPC

Relationship between saccadic eye movements and formation of the Krukenberg's spindle-a CFD study.

PubMed

Boushehrian, Hamidreza Hajiani; Abouali, Omid; Jafarpur, Khosrow; Ghaffarieh, Alireza; Ahmadi, Goodarz

2017-09-01

In this research, a series of numerical simulations for evaluating the effects of saccadic eye movement on the aqueous humour (AH) flow field and movement of pigment particles in the anterior chamber (AC) was performed. To predict the flow field of AH in the AC, the unsteady forms of continuity, momentum balance and conservation of energy equations were solved using the dynamic mesh technique for simulating the saccadic motions. Different orientations of the human eye including horizontal, vertical and angles of 10° and 20° were considered. The Lagrangian particle trajectory analysis approach was used to find the trajectories of pigment particles in the eye. Particular attention was given to the relation between the saccadic eye movement and potential formation of Krukenberg's spindle in the eye. The simulation results revealed that the natural convection flow was an effective mechanism for transferring pigment particles from the iris to near the cornea. In addition, the saccadic eye movement was the dominant mechanism for deposition of pigment particles on the cornea, which could lead to the formation of Krukenberg's spindle. The effect of amplitude of saccade motion angle in addition to the orientation of the eye on the formation of Krukenberg's spindle was investigated. © The authors 2016. Published by Oxford University Press on behalf of the Institute of Mathematics and its Applications. All rights reserved.

Eye movement analysis of reading from computer displays, eReaders and printed books.

PubMed

Zambarbieri, Daniela; Carniglia, Elena

2012-09-01

To compare eye movements during silent reading of three eBooks and a printed book. The three different eReading tools were a desktop PC, iPad tablet and Kindle eReader. Video-oculographic technology was used for recording eye movements. In the case of reading from the computer display the recordings were made by a video camera placed below the computer screen, whereas for reading from the iPad tablet, eReader and printed book the recording system was worn by the subject and had two cameras: one for recording the movement of the eyes and the other for recording the scene in front of the subject. Data analysis provided quantitative information in terms of number of fixations, their duration, and the direction of the movement, the latter to distinguish between fixations and regressions. Mean fixation duration was different only in reading from the computer display, and was similar for the Tablet, eReader and printed book. The percentage of regressions with respect to the total amount of fixations was comparable for eReading tools and the printed book. The analysis of eye movements during reading an eBook from different eReading tools suggests that subjects' reading behaviour is similar to reading from a printed book. © 2012 The College of Optometrists.

Blurring emotional memories using eye movements: individual differences and speed of eye movements.

PubMed

van Schie, Kevin; van Veen, Suzanne C; Engelhard, Iris M; Klugkist, Irene; van den Hout, Marcel A

2016-01-01

In eye movement desensitization and reprocessing (EMDR), patients make eye movements (EM) while recalling traumatic memories. Making EM taxes working memory (WM), which leaves less resources available for imagery of the memory. This reduces memory vividness and emotionality during future recalls. WM theory predicts that individuals with small working memory capacities (WMCs) benefit more from low levels of taxing (i.e., slow EM) whereas individuals with large WMC benefit more from high levels of taxing (i.e., fast EM). We experimentally examined and tested four prespecified hypotheses regarding the role of WMC and EM speed in reducing emotionality and vividness ratings: 1) EM-regardless of WMC and EM speed-are more effective compared to no dual task, 2) increasing EM speed only affects the decrease in memory ratings irrespective of WMC, 3) low-WMC individuals-compared to high-WMC individuals-benefit more from making either type of EM, 4) the EM intervention is most effective when-as predicted by WM theory-EM are adjusted to WMC. Undergraduates with low (n=31) or high (n=35) WMC recalled three emotional memories and rated vividness and emotionality before and after each condition (recall only, recall + slow EM, and recall + fast EM). Contrary to the theory, the data do not support the hypothesis that EM speed should be adjusted to WMC (hypothesis 4). However, the data show that a dual task in general is more effective in reducing memory ratings than no dual task (hypothesis 1), and that a more cognitively demanding dual task increases the intervention's effectiveness (hypothesis 2). Although adjusting EM speed to an individual's WMC seems a straightforward clinical implication, the data do not show any indication that such a titration is helpful.

Blurring emotional memories using eye movements: individual differences and speed of eye movements

PubMed Central

van Schie, Kevin; van Veen, Suzanne C.; Engelhard, Iris M.; Klugkist, Irene; van den Hout, Marcel A.

2016-01-01

Background In eye movement desensitization and reprocessing (EMDR), patients make eye movements (EM) while recalling traumatic memories. Making EM taxes working memory (WM), which leaves less resources available for imagery of the memory. This reduces memory vividness and emotionality during future recalls. WM theory predicts that individuals with small working memory capacities (WMCs) benefit more from low levels of taxing (i.e., slow EM) whereas individuals with large WMC benefit more from high levels of taxing (i.e., fast EM). Objective We experimentally examined and tested four prespecified hypotheses regarding the role of WMC and EM speed in reducing emotionality and vividness ratings: 1) EM—regardless of WMC and EM speed—are more effective compared to no dual task, 2) increasing EM speed only affects the decrease in memory ratings irrespective of WMC, 3) low-WMC individuals—compared to high-WMC individuals—benefit more from making either type of EM, 4) the EM intervention is most effective when—as predicted by WM theory—EM are adjusted to WMC. Method Undergraduates with low (n=31) or high (n=35) WMC recalled three emotional memories and rated vividness and emotionality before and after each condition (recall only, recall + slow EM, and recall + fast EM). Results Contrary to the theory, the data do not support the hypothesis that EM speed should be adjusted to WMC (hypothesis 4). However, the data show that a dual task in general is more effective in reducing memory ratings than no dual task (hypothesis 1), and that a more cognitively demanding dual task increases the intervention's effectiveness (hypothesis 2). Conclusions Although adjusting EM speed to an individual's WMC seems a straightforward clinical implication, the data do not show any indication that such a titration is helpful. PMID:27387843

Time-course of eye movement-related decrease in vividness and emotionality of unpleasant autobiographical memories.

PubMed

Smeets, Monique A M; Dijs, M Willem; Pervan, Iva; Engelhard, Iris M; van den Hout, Marcel A

2012-01-01

The time-course of changes in vividness and emotionality of unpleasant autobiographical memories associated with making eye movements (eye movement desensitisation and reprocessing, EMDR) was investigated. Participants retrieved unpleasant autobiographical memories and rated their vividness and emotionality prior to and following 96 seconds of making eye movements (EM) or keeping eyes stationary (ES); at 2, 4, 6, and 10 seconds into the intervention; then followed by regular larger intervals throughout the 96-second intervention. Results revealed a significant drop compared to the ES group in emotionality after 74 seconds compared to a significant drop in vividness at only 2 seconds into the intervention. These results support that emotionality becomes reduced only after vividness has dropped. The results are discussed in light of working memory theory and visual imagery theory, following which the regular refreshment of the visual memory needed to maintain it in working memory is interfered with by eye movements that also tax working memory, which affects vividness first.

Validation of an integrated software for the detection of rapid eye movement sleep behavior disorder.

PubMed

Frauscher, Birgit; Gabelia, David; Biermayr, Marlene; Stefani, Ambra; Hackner, Heinz; Mitterling, Thomas; Poewe, Werner; Högl, Birgit

2014-10-01

Rapid eye movement sleep without atonia (RWA) is the polysomnographic hallmark of REM sleep behavior disorder (RBD). To partially overcome the disadvantages of manual RWA scoring, which is time consuming but essential for the accurate diagnosis of RBD, we aimed to validate software specifically developed and integrated with polysomnography for RWA detection against the gold standard of manual RWA quantification. Academic referral center sleep laboratory. Polysomnographic recordings of 20 patients with RBD and 60 healthy volunteers were analyzed. N/A. Motor activity during REM sleep was quantified manually and computer assisted (with and without artifact detection) according to Sleep Innsbruck Barcelona (SINBAR) criteria for the mentalis ("any," phasic, tonic electromyographic [EMG] activity) and the flexor digitorum superficialis (FDS) muscle (phasic EMG activity). Computer-derived indices (with and without artifact correction) for "any," phasic, tonic mentalis EMG activity, phasic FDS EMG activity, and the SINBAR index ("any" mentalis + phasic FDS) correlated well with the manually derived indices (all Spearman rhos 0.66-0.98). In contrast with computerized scoring alone, computerized scoring plus manual artifact correction (median duration 5.4 min) led to a significant reduction of false positives for "any" mentalis (40%), phasic mentalis (40.6%), and the SINBAR index (41.2%). Quantification of tonic mentalis and phasic FDS EMG activity was not influenced by artifact correction. The computer algorithm used here appears to be a promising tool for REM sleep behavior disorder detection in both research and clinical routine. A short check for plausibility of automatic detection should be a basic prerequisite for this and all other available computer algorithms. © 2014 Associated Professional Sleep Societies, LLC.

Association of rapid eye movement sleep behavior disorder with sleep-disordered breathing in Parkinson's disease.

PubMed

Zhang, Lin-Yuan; Liu, Wen-Yan; Kang, Wen-Yan; Yang, Qiong; Wang, Xiao-Ying; Ding, Jian-Qing; Chen, Sheng-Di; Liu, Jun

2016-04-01

Rapid eye movement (REM) sleep behavior disorder (RBD) and sleep-disordered breathing (SDB) are two major sleep disturbances observed in patients with Parkinson's disease (PD). However, prior studies exploring the clinical correlations between RBD and SDB in PD have been limited. We aimed to investigate the relationship between RBD and SDB in PD using a case-control study. A total of 46 PD patients with Hoehn-Yahr stages ranging from 1 to 3 participated in the present study. Participants underwent polysomnography to diagnose the presence of RBD and SDB, and were classified into groups, accordingly. SDB was defined as an apnea-hypopnea index greater than 5. Comparison of clinical and sleep-respiratory parameters was performed among them. SDB was more frequent in the RBD group than in the non-RBD group (51.4% vs 9.1%, p = 0.016). PD patients with RBD had significantly reduced mean SaO2 and more severe sleep apnea-related parameters during total sleep and non-REM sleep in comparison with non-RBD PD patients. However, there were no differences on the REM-related apnea/hypopnea variables between participants with and without RBD (p > 0.05). Both the frequency of RBD and RBD screening questionnaire (RBDSQ) scores were higher in the participants with SDB than in the participants without SDB (p <0.05). Furthermore, a significant negative correlation was found between RBDSQ and mean SaO2 in all participants. In PD patients, SDB is more frequent and more severe in patients with RBD than in patients without, and RBD increases the risk of hypoxemia during sleep. Copyright © 2016 Elsevier B.V. All rights reserved.

Role of the human supplementary eye field in the control of saccadic eye movements

PubMed Central

Parton, Andrew; Nachev, Parashkev; Hodgson, Timothy L.; Mort, Dominic; Thomas, David; Ordidge, Roger; Morgan, Paul S.; Jackson, Stephen; Rees, Geraint; Husain, Masud

2007-01-01

The precise function of the supplementary eye field (SEF) is poorly understood. Although electrophysiological and functional imaging studies are important for demonstrating when SEF neurones are active, lesion studies are critical to establish the functions for which the SEF is essential. Here we report a series of investigations performed on an extremely rare individual with a highly focal lesion of the medial frontal cortex. High-resolution structural imaging demonstrated that his lesion was confined to the region of the left paracentral sulcus, the anatomical locus of the SEF. Behavioural testing revealed that the patient was significantly impaired when required to switch between anti- and pro-saccades, when there were conflicting rules governing stimulus–response mappings for saccades. Similarly, the results of an arbitrary stimulus–response associative learning task demonstrated that he was impaired when required to select the appropriate saccade from conflicting eye movement responses, but not for limb movements on an analogous manual task. When making memory-guided saccadic sequences, the patient demonstrated hypometria, like patients with Parkinson's disease, but had no significant difficulties in reproducing the order of saccades correctly on a task that emphasized accuracy with a wide temporal segregation between responses. These findings are consistent with the hypothesis that the SEF plays a key role in implementing control when there is conflict between several, ongoing competing saccadic responses, but not when eye movements need to be made accurately in sequence. PMID:17069864

The relationship between eye movements and subsequent recognition: Evidence from individual differences and amnesia.

PubMed

Olsen, Rosanna K; Sebanayagam, Vinoja; Lee, Yunjo; Moscovitch, Morris; Grady, Cheryl L; Rosenbaum, R Shayna; Ryan, Jennifer D

2016-12-01

There is consistent agreement regarding the positive relationship between cumulative eye movement sampling and subsequent recognition, but the role of the hippocampus in this sampling behavior is currently unknown. It is also unclear whether the eye movement repetition effect, i.e., fewer fixations to repeated, compared to novel, stimuli, depends on explicit recognition and/or an intact hippocampal system. We investigated the relationship between cumulative sampling, the eye movement repetition effect, subsequent memory, and the hippocampal system. Eye movements were monitored in a developmental amnesic case (H.C.), whose hippocampal system is compromised, and in a group of typically developing participants while they studied single faces across multiple blocks. The faces were studied from the same viewpoint or different viewpoints and were subsequently tested with the same or different viewpoint. Our previous work suggested that hippocampal representations support explicit recognition for information that changes viewpoint across repetitions (Olsen et al., 2015). Here, examination of eye movements during encoding indicated that greater cumulative sampling was associated with better memory among controls. Increased sampling, however, was not associated with better explicit memory in H.C., suggesting that increased sampling only improves memory when the hippocampal system is intact. The magnitude of the repetition effect was not correlated with cumulative sampling, nor was it related reliably to subsequent recognition. These findings indicate that eye movements collect information that can be used to strengthen memory representations that are later available for conscious remembering, whereas eye movement repetition effects reflect a processing change due to experience that does not necessarily reflect a memory representation that is available for conscious appraisal. Lastly, H.C. demonstrated a repetition effect for fixed viewpoint faces but not for variable

Human vertical eye movement responses to earth horizontal pitch

NASA Technical Reports Server (NTRS)

Wall, C. 3rd; Petropoulos, A. E.

1993-01-01

The vertical eye movements in humans produced in response to head-over-heels constant velocity pitch rotation about a horizontal axis resemble those from other species. At 60 degrees/s these are persistent and tend to have non-reversing slow components that are compensatory to the direction of rotation. In most, but not all subjects, the slow component velocity was well characterized by a rapid build-up followed by an exponential decay to a non-zero baseline. Super-imposed was a cyclic or modulation component whose frequency corresponded to the time for one revolution and whose maximum amplitude occurred during a specific head orientation. All response components (exponential decay, baseline and modulation) were larger during pitch backward compared to pitch forward runs. Decay time constants were shorter during the backward runs, thus, unlike left to right yaw axis rotation, pitch responses display significant asymmetries between paired forward and backward runs.

Summation of visual motion across eye movements reflects a nonspatial decision mechanism.

PubMed

Morris, Adam P; Liu, Charles C; Cropper, Simon J; Forte, Jason D; Krekelberg, Bart; Mattingley, Jason B

2010-07-21

Human vision remains perceptually stable even though retinal inputs change rapidly with each eye movement. Although the neural basis of visual stability remains unknown, a recent psychophysical study pointed to the existence of visual feature-representations anchored in environmental rather than retinal coordinates (e.g., "spatiotopic" receptive fields; Melcher and Morrone, 2003). In that study, sensitivity to a moving stimulus presented after a saccadic eye movement was enhanced when preceded by another moving stimulus at the same spatial location before the saccade. The finding is consistent with spatiotopic sensory integration, but it could also have arisen from a probabilistic improvement in performance due to the presence of more than one motion signal for the perceptual decision. Here we show that this statistical advantage accounts completely for summation effects in this task. We first demonstrate that measurements of summation are confounded by noise related to an observer's uncertainty about motion onset times. When this uncertainty is minimized, comparable summation is observed regardless of whether two motion signals occupy the same or different locations in space, and whether they contain the same or opposite directions of motion. These results are incompatible with the tuning properties of motion-sensitive sensory neurons and provide no evidence for a spatiotopic representation of visual motion. Instead, summation in this context reflects a decision mechanism that uses abstract representations of sensory events to optimize choice behavior.

Integrated database for rapid mass movements in Norway

NASA Astrophysics Data System (ADS)

Jaedicke, C.; Lied, K.; Kronholm, K.

2009-03-01

Rapid gravitational slope mass movements include all kinds of short term relocation of geological material, snow or ice. Traditionally, information about such events is collected separately in different databases covering selected geographical regions and types of movement. In Norway the terrain is susceptible to all types of rapid gravitational slope mass movements ranging from single rocks hitting roads and houses to large snow avalanches and rock slides where entire mountainsides collapse into fjords creating flood waves and endangering large areas. In addition, quick clay slides occur in desalinated marine sediments in South Eastern and Mid Norway. For the authorities and inhabitants of endangered areas, the type of threat is of minor importance and mitigation measures have to consider several types of rapid mass movements simultaneously. An integrated national database for all types of rapid mass movements built around individual events has been established. Only three data entries are mandatory: time, location and type of movement. The remaining optional parameters enable recording of detailed information about the terrain, materials involved and damages caused. Pictures, movies and other documentation can be uploaded into the database. A web-based graphical user interface has been developed allowing new events to be entered, as well as editing and querying for all events. An integration of the database into a GIS system is currently under development. Datasets from various national sources like the road authorities and the Geological Survey of Norway were imported into the database. Today, the database contains 33 000 rapid mass movement events from the last five hundred years covering the entire country. A first analysis of the data shows that the most frequent type of recorded rapid mass movement is rock slides and snow avalanches followed by debris slides in third place. Most events are recorded in the steep fjord terrain of the Norwegian west coast, but

Effect of viewing distance on the generation of vertical eye movements during locomotion

NASA Technical Reports Server (NTRS)

Moore, S. T.; Hirasaki, E.; Cohen, B.; Raphan, T.

1999-01-01

Vertical head and eye coordination was studied as a function of viewing distance during locomotion. Vertical head translation and pitch movements were measured using a video motion analysis system (Optotrak 3020). Vertical eye movements were recorded using a video-based pupil tracker (Iscan). Subjects (five) walked on a linear treadmill at a speed of 1.67 m/s (6 km/h) while viewing a target screen placed at distances ranging from 0.25 to 2.0 m at 0. 25-m intervals. The predominant frequency of vertical head movement was 2 Hz. In accordance with previous studies, there was a small head pitch rotation, which was compensatory for vertical head translation. The magnitude of the vertical head movements and the phase relationship between head translation and pitch were little affected by viewing distance, and tended to orient the naso-occipital axis of the head at a point approximately 1 m in front of the subject (the head fixation distance or HFD). In contrast, eye velocity was significantly affected by viewing distance. When viewing a far (2-m) target, vertical eye velocity was 180 degrees out of phase with head pitch velocity, with a gain of 0. 8. This indicated that the angular vestibulo-ocular reflex (aVOR) was generating the eye movement response. The major finding was that, at a close viewing distance (0.25 m), eye velocity was in phase with head pitch and compensatory for vertical head translation, suggesting that activation of the linear vestibulo-ocular reflex (lVOR) was contributing to the eye movement response. There was also a threefold increase in the magnitude of eye velocity when viewing near targets, which was consistent with the goal of maintaining gaze on target. The required vertical lVOR sensitivity to cancel an unmodified aVOR response and generate the observed eye velocity magnitude for near targets was almost 3 times that previously measured. Supplementary experiments were performed utilizing body-fixed active head pitch rotations at 1 and 2 Hz

Endogenous excitatory drive to the respiratory system in rapid eye movement sleep in cats.

PubMed

Orem, J; Lovering, A T; Dunin-Barkowski, W; Vidruk, E H

2000-09-01

A putative endogenous excitatory drive to the respiratory system in rapid eye movement (REM) sleep may explain many characteristics of breathing in that state, e.g. its irregularity and variable ventilatory responses to chemical stimuli. This drive is hypothetical, and determinations of its existence and character are complicated by control of the respiratory system by the oscillator and its feedback mechanisms. In the present study, endogenous drive was studied during apnoea caused by mechanical hyperventilation. We reasoned that if there was a REM-dependent drive to the respiratory system, then respiratory activity should emerge out of the background apnoea as a manifestation of the drive. Diaphragmatic muscle or medullary respiratory neuronal activity was studied in five intact, unanaesthetized adult cats who were either mechanically hyperventilated or breathed spontaneously in more than 100 REM sleep periods. Diaphragmatic activity emerged out of a background apnoea caused by mechanical hyperventilation an average of 34 s after the onset of REM sleep. Emergent activity occurred in 60 % of 10 s epochs in REM sleep and the amount of activity per unit time averaged approximately 40 % of eupnoeic activity. The activity occurred in episodes and was poorly related to pontogeniculo-occipital waves. At low CO2 levels, this activity was non-rhythmic. At higher CO2 levels (less than 0.5 % below eupnoeic end-tidal percentage CO2 levels in non-REM (NREM) sleep), activity became rhythmic. Medullary respiratory neurons were recorded in one of the five animals. Nineteen of twenty-seven medullary respiratory neurons were excited in REM sleep during apnoea. Excited neurons included inspiratory, expiratory and phase-spanning neurons. Excitation began about 43 s after the onset of REM sleep. Activity increased from an average of 6 impulses s-1 in NREM sleep to 15.5 impulses s-1 in REM sleep. Neuronal activity was non-rhythmic at low CO2 levels and became rhythmic when levels were

Eye Movement Desensitization and Reprocessing: A Critical Analysis.

ERIC Educational Resources Information Center

Erwin, Terry McVannel

Since Shapiro's introduction of Eye Movement Desensitization and Reprocessing (EMDR) in 1989, it has been a highly controversial therapeutic technique. Critical reviews of Shapiro's initial study have highlighted many methodological shortcomings in her work. And early empirical research that followed Shapiro's original study has been criticized…

Eye-Movement Analysis Demonstrates Strategic Influences on Intelligence

ERIC Educational Resources Information Center

Vigneau, Francois; Caissie, Andre F.; Bors, Douglas A.

2006-01-01

Taking into account various models and findings pertaining to the nature of analogical reasoning, this study explored quantitative and qualitative individual differences in intelligence using latency and eye-movement data. Fifty-five university students were administered 14 selected items of the Raven's Advanced Progressive Matrices test. Results…

Underlying Changes in Repeated Reading: An Eye Movement Study

ERIC Educational Resources Information Center

Foster, Tori E.; Ardoin, Scott P.; Binder, Katherine S.

2013-01-01

conclusive evidence as to the mechanisms through which RR takes effect. Eye movement studies allow for precise examination of intervention effects. The current study examined underlying changes in elementary students' ("N" = 43) reading behavior…

Dynamic scanpaths: eye movement analysis methods

NASA Astrophysics Data System (ADS)

Blackmon, Theodore T.; Ho, Yeuk F.; Chernyak, Dimitri A.; Azzariti, Michela; Stark, Lawrence W.

1999-05-01

An eye movements sequence, or scanpath, during viewing of a stationary stimulus has been described as a set of fixations onto regions-of-interest, ROIs, and the saccades or transitions between them. Such scanpaths have high similarity for the same subject and stimulus both in the spatial loci of the ROIs and their sequence; scanpaths also take place during recollection of a previously viewed stimulus, suggesting that they play a similar role in visual memory and recall.

Children's Eye Movements, Miscue Analysis Patterns, and Retellings When Reading a Counterpoint Picture Book

ERIC Educational Resources Information Center

Liwanag, Maria Perpetua Socorro U.; Pelatti, Christina Yeager; Martens, Ray; Martens, Prisca

2016-01-01

This study incorporated eye movement miscue analysis to investigate two second-graders' oral reading and comprehension of a counterpoint picture book. Findings suggest the second-graders' strategies when reading the written and pictorial text affected their comprehension as opposed to the number and location of their eye movements. Specifically,…

Using Eye Movements to Model the Sequence of Text-Picture Processing for Multimedia Comprehension

ERIC Educational Resources Information Center

Mason, L.; Scheiter, K.; Tornatora, M. C.

2017-01-01

This study used eye movement modeling examples (EMME) to support students' integrative processing of verbal and graphical information during the reading of an illustrated text. EMME consists of a replay of eye movements of a model superimposed onto the materials that are processed for accomplishing the task. Specifically, the study investigated…

Eye Tracking and Head Movement Detection: A State-of-Art Survey

PubMed Central

2013-01-01

Eye-gaze detection and tracking have been an active research field in the past years as it adds convenience to a variety of applications. It is considered a significant untraditional method of human computer interaction. Head movement detection has also received researchers' attention and interest as it has been found to be a simple and effective interaction method. Both technologies are considered the easiest alternative interface methods. They serve a wide range of severely disabled people who are left with minimal motor abilities. For both eye tracking and head movement detection, several different approaches have been proposed and used to implement different algorithms for these technologies. Despite the amount of research done on both technologies, researchers are still trying to find robust methods to use effectively in various applications. This paper presents a state-of-art survey for eye tracking and head movement detection methods proposed in the literature. Examples of different fields of applications for both technologies, such as human-computer interaction, driving assistance systems, and assistive technologies are also investigated. PMID:27170851

Hemianopic and Quadrantanopic Field Loss, Eye and Head Movements, and Driving

PubMed Central

McGwin, Gerald; Elgin, Jennifer; Vaphiades, Michael S.; Braswell, Ronald A.; DeCarlo, Dawn K.; Kline, Lanning B.; Owsley, Cynthia

2011-01-01

Purpose. To compare eye and head movements, lane keeping, and vehicle control of drivers with hemianopic and quadrantanopic field defects with controls, and to identify differences in these parameters between hemianopic and quadrantanopic drivers rated safe to drive by a clinical driving rehabilitation specialist compared with those rated as unsafe. Methods. Eye and head movements and lane keeping were rated in 22 persons with homonymous hemianopic defects and 8 with quadrantanopic defects (mean age, 53 years) who were ≥6 months post-injury and 30 persons with normal fields (mean age, 53 years). All were licensed to drive and were current drivers or aimed to resume driving. Participants drove a 6.3-mile route along non-interstate city roads under in-traffic conditions. Vehicle control was assessed objectively by vehicle instrumentation for speed, braking, acceleration, and cornering. Results. As a group, drivers with hemianopic or quadrantanopic defects drove slower, exhibited less excessive cornering or acceleration, and executed more shoulder movements than the controls. Those drivers with hemianopic or quadrantanopic defects rated as safe also made more head movements into their blind field, received superior ratings regarding eye movement extent and lane position stability, and exhibited less sudden braking and drove faster than those rated unsafe. Conclusions. Persons with hemianopic and quadrantanopic defects rated as safe to drive compensated by making more head movements into their blind field, combined with more stable lane keeping and less sudden braking. Future research should evaluate whether these characteristics could be trained in rehabilitation programs aimed at improving driving safety in this population. PMID:21367969

Saccadic eye movement metrics reflect surgical residents' fatigue.

PubMed

Di Stasi, Leandro L; McCamy, Michael B; Macknik, Stephen L; Mankin, James A; Hooft, Nicole; Catena, Andrés; Martinez-Conde, Susana

2014-04-01

Little is known about the effects of surgical residents' fatigue on patient safety. We monitored surgical residents' fatigue levels during their call day using (1) eye movement metrics, (2) objective measures of laparoscopic surgical performance, and (3) subjective reports based on standardized questionnaires. Prior attempts to investigate the effects of fatigue on surgical performance have suffered from methodological limitations, including inconsistent definitions and lack of objective measures of fatigue, and nonstandardized measures of surgical performance. Recent research has shown that fatigue can affect the characteristics of saccadic (fast ballistic) eye movements in nonsurgical scenarios. Here we asked whether fatigue induced by time-on-duty (~24 hours) might affect saccadic metrics in surgical residents. Because saccadic velocity is not under voluntary control, a fatigue index based on saccadic velocity has the potential to provide an accurate and unbiased measure of the resident's fatigue level. We measured the eye movements of members of the general surgery resident team at St. Joseph's Hospital and Medical Center (Phoenix, AZ) (6 males and 6 females), using a head-mounted video eye tracker (similar configuration to a surgical headlight), during the performance of 3 tasks: 2 simulated laparoscopic surgery tasks (peg transfer and precision cutting) and a guided saccade task, before and after their call day. Residents rated their perceived fatigue level every 3 hours throughout their 24-hour shift, using a standardized scale. Time-on-duty decreased saccadic velocity and increased subjective fatigue but did not affect laparoscopic performance. These results support the hypothesis that saccadic indices reflect graded changes in fatigue. They also indicate that fatigue due to prolonged time-on-duty does not result necessarily in medical error, highlighting the complicated relationship among continuity of care, patient safety, and fatigued providers. Our data

Saccadic Eye Movement Improves Plantar Sensation and Postural Balance in Elderly Women.

PubMed

Bae, Youngsook

2016-06-01

Vision, proprioception and plantar sensation contribute to the control of postural balance (PB). Reduced plantar sensation alters postural response and is at an increased risk of fall, and eye movements reduce the postural sway. Therefore, the aim of this study was to study the improvement of plantar sensation and PB after saccadic eye movement (SEM) and pursuit eye movement (PEM) in community-dwelling elderly women. Participants (104 females; 75.11 ± 6.25 years) were randomly allocated into the SEM group (n = 52) and PEM groups (n = 52). The SEM group performed eye fixation and SEM for 5 minutes, and the PEM group performed eye fixation and PEM for 5 minutes. The plantar sensation was measured according to the plantar surface area of the feet in contact with the floor surface before and after the intervention. Before and after SEM and PEM with the eyes open and closed, PB was measured as the area (mm(2)), length (cm), and velocity (cm/s) of the fluctuation of the center of pressure (COP). The plantar sensation of both feet improved in both groups (p < 0.01). Significant decreases in the area, length, and velocity of the COP were observed in the eye open and close in both groups (p < 0.01). The length and velocity of the COP significantly decreased in the SEM group compared to the PEM group (p < 0.05). In conclusion, SEM and PEM are effective interventions for improving plantar sensation and PB in elderly women, with greater PB improvement after SEM.

The Benefit of Directed Forgetting Persists After a Daytime Nap: The Role of Spindles and Rapid Eye Movement Sleep in the Consolidation of Relevant Memories.

PubMed

Blaskovich, Borbála; Szollosi, Ágnes; Gombos, Ferenc; Racsmány, Mihály; Simor, Péter

2017-03-01