Automotive Mechanics. Student Learning Guides.

ERIC Educational Resources Information Center

Ridge Vocational-Technical Center, Winter Haven, FL.

These 33 learning guides are self-instructional packets for 33 tasks identified as essential for performance on an entry-level job in automotive mechanics. Each guide is based on a terminal performance objective (task) and 1-9 enabling objectives. For each enabliing objective, some or all of these materials may be presented: learning steps…

Mechanical Drafting. Student Learning Guides.

ERIC Educational Resources Information Center

Ridge Vocational-Technical Center, Winter Haven, FL.

These four learning guides are self-instructional packets for four tasks identified as essential for performance on an entry-level job in mechanical drafting. Each guide is based on a terminal performance objective (task) and 2-4 enabling objectives. For each enabling objective, some or all of these materials may be presented: learning steps…

Livestock. Student Learning Guides.

ERIC Educational Resources Information Center

Ridge Vocational-Technical Center, Winter Haven, FL.

These 25 learning guides are self-instructional packets for 25 tasks identified as essential for performance on an entry-level job in livestock production. Each guide is based on a terminal performance objective (task) and 1-4 enabling objectives. For each enabling objective, some or all of these materials may be presented: learning steps (outline…

The subjective experience of object recognition: comparing metacognition for object detection and object categorization.

PubMed

Meuwese, Julia D I; van Loon, Anouk M; Lamme, Victor A F; Fahrenfort, Johannes J

2014-05-01

Perceptual decisions seem to be made automatically and almost instantly. Constructing a unitary subjective conscious experience takes more time. For example, when trying to avoid a collision with a car on a foggy road you brake or steer away in a reflex, before realizing you were in a near accident. This subjective aspect of object recognition has been given little attention. We used metacognition (assessed with confidence ratings) to measure subjective experience during object detection and object categorization for degraded and masked objects, while objective performance was matched. Metacognition was equal for degraded and masked objects, but categorization led to higher metacognition than did detection. This effect turned out to be driven by a difference in metacognition for correct rejection trials, which seemed to be caused by an asymmetry of the distractor stimulus: It does not contain object-related information in the detection task, whereas it does contain such information in the categorization task. Strikingly, this asymmetry selectively impacted metacognitive ability when objective performance was matched. This finding reveals a fundamental difference in how humans reflect versus act on information: When matching the amount of information required to perform two tasks at some objective level of accuracy (acting), metacognitive ability (reflecting) is still better in tasks that rely on positive evidence (categorization) than in tasks that rely more strongly on an absence of evidence (detection).

Children's construction task performance and spatial ability: controlling task complexity and predicting mathematics performance.

PubMed

Richardson, Miles; Hunt, Thomas E; Richardson, Cassandra

2014-12-01

This paper presents a methodology to control construction task complexity and examined the relationships between construction performance and spatial and mathematical abilities in children. The study included three groups of children (N = 96); ages 7-8, 10-11, and 13-14 years. Each group constructed seven pre-specified objects. The study replicated and extended previous findings that indicated that the extent of component symmetry and variety, and the number of components for each object and available for selection, significantly predicted construction task difficulty. Results showed that this methodology is a valid and reliable technique for assessing and predicting construction play task difficulty. Furthermore, construction play performance predicted mathematical attainment independently of spatial ability.

Parts Marketing. A Student Learning Guide.

ERIC Educational Resources Information Center

Ridge Vocational-Technical Center, Winter Haven, FL.

This learning guide is a self-instructional packet for one task identified as essential for performance on an entry-level job in parts marketing. The guide is based on a terminal performance objective (task) and two enabling objectives. For each enabling objective, some or all of these materials may be presented: learning steps (outline of student…

Welding. Student Learning Guides.

ERIC Educational Resources Information Center

Ridge Vocational-Technical Center, Winter Haven, FL.

These 23 learning guides are self-instructional packets for 23 tasks identified as essential for performance on an entry-level job in welding. Each guide is based on a terminal performance objective (task) and 1-4 enabling objectives. For each enabling objective, some or all of these materials may be presented: learning steps (outline of student…

Plumbing and Pipefitting. Student Learning Guides.

ERIC Educational Resources Information Center

Ridge Vocational-Technical Center, Winter Haven, FL.

These 32 learning guides are self-instructional packets for 32 tasks identified as essential for performance on an entry-level job in plumbing and pipefitting. Each guide is based on a terminal performance objective (task) and 1-4 enabling objectives. For each enabling objective, some or all of these materials may be presented: learning steps…

Clothing Production. Student Learning Guides.

ERIC Educational Resources Information Center

Ridge Vocational-Technical Center, Winter Haven, FL.

These 59 learning guides are self-instructional packets for 59 tasks identified as essential for performance on an entry-level job in clothing production. Each guide is based on a terminal performance objective (task) and 2-5 enabling objectives. For each enabling objective, some or all of these materials may be presented: learning steps (outline…

Effects of motor congruence on visual working memory.

PubMed

Quak, Michel; Pecher, Diane; Zeelenberg, Rene

2014-10-01

Grounded-cognition theories suggest that memory shares processing resources with perception and action. The motor system could be used to help memorize visual objects. In two experiments, we tested the hypothesis that people use motor affordances to maintain object representations in working memory. Participants performed a working memory task on photographs of manipulable and nonmanipulable objects. The manipulable objects were objects that required either a precision grip (i.e., small items) or a power grip (i.e., large items) to use. A concurrent motor task that could be congruent or incongruent with the manipulable objects caused no difference in working memory performance relative to nonmanipulable objects. Moreover, the precision- or power-grip motor task did not affect memory performance on small and large items differently. These findings suggest that the motor system plays no part in visual working memory.

Characterizing “fibrofog”: Subjective appraisal, objective performance, and task-related brain activity during a working memory task

PubMed Central

Walitt, Brian; Čeko, Marta; Khatiwada, Manish; Gracely, John L.; Rayhan, Rakib; VanMeter, John W.; Gracely, Richard H.

2016-01-01

The subjective experience of cognitive dysfunction (“fibrofog”) is common in fibromyalgia. This study investigated the relation between subjective appraisal of cognitive function, objective cognitive task performance, and brain activity during a cognitive task using functional magnetic resonance imaging (fMRI). Sixteen fibromyalgia patients and 13 healthy pain-free controls completed a battery of questionnaires, including the Multiple Ability Self-Report Questionnaire (MASQ), a measure of self-perceived cognitive difficulties. Participants were evaluated for working memory performance using a modified N-back working memory task while undergoing Blood Oxygen Level Dependent (BOLD) fMRI measurements. Fibromyalgia patients and controls did not differ in working memory performance. Subjective appraisal of cognitive function was associated with better performance (accuracy) on the working memory task in healthy controls but not in fibromyalgia patients. In fibromyalgia patients, increased perceived cognitive difficulty was positively correlated with the severity of their symptoms. BOLD response during the working memory task did not differ between the groups. BOLD response correlated with task accuracy in control subjects but not in fibromyalgia patients. Increased subjective cognitive impairment correlated with decreased BOLD response in both groups but in different anatomic regions. In conclusion, “fibrofog” appears to be better characterized by subjective rather than objective impairment. Neurologic correlates of this subjective experience of impairment might be separate from those involved in the performance of cognitive tasks. PMID:26955513

Characterizing "fibrofog": Subjective appraisal, objective performance, and task-related brain activity during a working memory task.

PubMed

Walitt, Brian; Čeko, Marta; Khatiwada, Manish; Gracely, John L; Rayhan, Rakib; VanMeter, John W; Gracely, Richard H

2016-01-01

The subjective experience of cognitive dysfunction ("fibrofog") is common in fibromyalgia. This study investigated the relation between subjective appraisal of cognitive function, objective cognitive task performance, and brain activity during a cognitive task using functional magnetic resonance imaging (fMRI). Sixteen fibromyalgia patients and 13 healthy pain-free controls completed a battery of questionnaires, including the Multiple Ability Self-Report Questionnaire (MASQ), a measure of self-perceived cognitive difficulties. Participants were evaluated for working memory performance using a modified N-back working memory task while undergoing Blood Oxygen Level Dependent (BOLD) fMRI measurements. Fibromyalgia patients and controls did not differ in working memory performance. Subjective appraisal of cognitive function was associated with better performance (accuracy) on the working memory task in healthy controls but not in fibromyalgia patients. In fibromyalgia patients, increased perceived cognitive difficulty was positively correlated with the severity of their symptoms. BOLD response during the working memory task did not differ between the groups. BOLD response correlated with task accuracy in control subjects but not in fibromyalgia patients. Increased subjective cognitive impairment correlated with decreased BOLD response in both groups but in different anatomic regions. In conclusion, "fibrofog" appears to be better characterized by subjective rather than objective impairment. Neurologic correlates of this subjective experience of impairment might be separate from those involved in the performance of cognitive tasks.

Visuospatial deficits in schizophrenia: central executive and memory subsystems impairments.

PubMed

Leiderman, Eduardo A; Strejilevich, Sergio A

2004-06-01

Object and spatial visual working memory are impaired in schizophrenic patients. It is not clear if the impairments reside in each memory subsystem alone or also in the central executive component that coordinates these processes. In order to elucidate which memory component is impaired, we developed a paradigm with single spatial and object working memory tasks and dual ones with two different delays (5 and 30 s). Fifteen schizophrenic patients and 14 control subjects performed these tests. Schizophrenic patients had a poorer performance compared to normal controls in all tasks and in all time delays. Both schizophrenics and controls performed significantly worse in the object task than in the spatial task. The performance was even worse in the dual task compared to the singles ones in schizophrenic patients but not in controls. These data suggest that visuospatial performance deficits in schizophrenia are due to both visuospatial memory subsystems impairments and central executive ones. The pattern of deficits observed points to a codification or evocation deficit and not to a maintenance one.

Object versus spatial visual mental imagery in patients with schizophrenia

PubMed Central

Aleman, André; de Haan, Edward H.F.; Kahn, René S.

2005-01-01

Objective Recent research has revealed a larger impairment of object perceptual discrimination than of spatial perceptual discrimination in patients with schizophrenia. It has been suggested that mental imagery may share processing systems with perception. We investigated whether patients with schizophrenia would show greater impairment regarding object imagery than spatial imagery. Methods Forty-four patients with schizophrenia and 20 healthy control subjects were tested on a task of object visual mental imagery and on a task of spatial visual mental imagery. Both tasks included a condition in which no imagery was needed for adequate performance, but which was in other respects identical to the imagery condition. This allowed us to adjust for nonspecific differences in individual performance. Results The results revealed a significant difference between patients and controls on the object imagery task (F1,63 = 11.8, p = 0.001) but not on the spatial imagery task (F1,63 = 0.14, p = 0.71). To test for a differential effect, we conducted a 2 (patients v. controls) х 2 (object task v. spatial task) analysis of variance. The interaction term was statistically significant (F1,62 = 5.2, p = 0.026). Conclusions Our findings suggest a differential dysfunction of systems mediating object and spatial visual mental imagery in schizophrenia. PMID:15644999

Flexibility in Visual Working Memory: Accurate Change Detection in the Face of Irrelevant Variations in Position

PubMed Central

Woodman, Geoffrey F.; Vogel, Edward K.; Luck, Steven J.

2012-01-01

Many recent studies of visual working memory have used change-detection tasks in which subjects view sequential displays and are asked to report whether they are identical or if one object has changed. A key question is whether the memory system used to perform this task is sufficiently flexible to detect changes in object identity independent of spatial transformations, but previous research has yielded contradictory results. To address this issue, the present study compared standard change-detection tasks with tasks in which the objects varied in size or position between successive arrays. Performance was nearly identical across the standard and transformed tasks unless the task implicitly encouraged spatial encoding. These results resolve the discrepancies in prior studies and demonstrate that the visual working memory system can detect changes in object identity across spatial transformations. PMID:22287933

14- to 16-Month-Olds Attend to Distinct Labels in an Inductive Reasoning Task.

PubMed

Switzer, Jessica L; Graham, Susan A

2017-01-01

We examined how naming objects with unique labels influenced infants' reasoning about the non-obvious properties of novel objects. Seventy 14- to 16-month-olds participated in an imitation-based inductive inference task during which they were presented with target objects possessing a non-obvious sound property, followed by test objects that varied in shape similarity in comparison to the target. Infants were assigned to one of two groups: a No Label group in which objects were introduced with a general attentional phrase (i.e., "Look at this one") and a Distinct Label group in which target and test objects were labeled with two distinct count nouns (i.e., fep vs. wug ). Infants in the Distinct Label group performed significantly fewer target actions on the high-similarity objects than infants in the No Label group but did not differ in performance of actions on the low-similarity object. Within the Distinct Label group, performance on the inductive inference task was related to age, but not to working memory, inhibitory control, or vocabulary. Within the No Label condition, performance on the inductive inference task was related to a measure of inhibitory control. Our findings suggest that between 14- and 16-months, infants begin to use labels to carve out distinct categories, even when objects are highly perceptually similar.

Objective Fidelity Evaluation in Multisensory Virtual Environments: Auditory Cue Fidelity in Flight Simulation

PubMed Central

Meyer, Georg F.; Wong, Li Ting; Timson, Emma; Perfect, Philip; White, Mark D.

2012-01-01

We argue that objective fidelity evaluation of virtual environments, such as flight simulation, should be human-performance-centred and task-specific rather than measure the match between simulation and physical reality. We show how principled experimental paradigms and behavioural models to quantify human performance in simulated environments that have emerged from research in multisensory perception provide a framework for the objective evaluation of the contribution of individual cues to human performance measures of fidelity. We present three examples in a flight simulation environment as a case study: Experiment 1: Detection and categorisation of auditory and kinematic motion cues; Experiment 2: Performance evaluation in a target-tracking task; Experiment 3: Transferrable learning of auditory motion cues. We show how the contribution of individual cues to human performance can be robustly evaluated for each task and that the contribution is highly task dependent. The same auditory cues that can be discriminated and are optimally integrated in experiment 1, do not contribute to target-tracking performance in an in-flight refuelling simulation without training, experiment 2. In experiment 3, however, we demonstrate that the auditory cue leads to significant, transferrable, performance improvements with training. We conclude that objective fidelity evaluation requires a task-specific analysis of the contribution of individual cues. PMID:22957068

“So Big”: The Development of Body Self-awareness in Toddlers

PubMed Central

Brownell, Celia A.; Zerwas, Stephanie; Ramani, Geetha B.

2012-01-01

Early development of body self-awareness was examined in 57 children at 18, 22, or 26 months of age, using tasks designed to require objective representation of one’s own body. All children made at least one body representation error, with approximately 2.5 errors per task on average. Errors declined with age. Children’s performance on comparison tasks that required them to reason about the relative size of objects and about objects as obstacles, without considering their own bodies, was unrelated to performance on the body awareness tasks. Thus, the ability to represent and reflect on one’s own body explicitly and objectively may be a unique dimension of early development, a distinct component of objective self-awareness which emerges in this age period. PMID:17883440

Commercial Foods and Culinary Arts. Student Learning Guides.

ERIC Educational Resources Information Center

Ridge Vocational-Technical Center, Winter Haven, FL.

These 13 learning guides are self-instructional packets for 13 tasks identified as essential for performance on an entry-level job in commercial foods and culinary arts. Each guide is based on a terminal performance objective (task) and 1-4 enabling objectives. For each enabling objective, some or all of these materials may be presented: learning…

Object permanence in common marmosets (Callithrix jacchus).

PubMed

Mendes, Natacha; Huber, Ludwig

2004-03-01

A series of 9 search tasks corresponding to the Piagetian Stages 3-6 of object permanence were administered to 11 common marmosets (Callithrix jacchus). Success rates varied strongly among tasks and marmosets, but the performances of most subjects were above chance level on the majority of tasks of visible and invisible displacements. Although up to 24 trials were administered in the tests, subjects did not improve their performance across trials. Errors were due to preferences for specific locations or boxes, simple search strategies, and attentional deficits. The performances of at least 2 subjects that achieved very high scores up to the successive invisible displacement task suggest that this species is able to represent the existence and the movements of unperceived objects. ((c) 2004 APA, all rights reserved)

F-16 Task Analysis Criterion-Referenced Objective and Objectives Hierarchy Report. Volume 4

DTIC Science & Technology

1981-03-01

Initiation cues: Engine flameout Systems presenting cues: Aircraft fuel, engine STANDARD: Authority: TACR 60-2 Performance precision: TD in first 1/3 of...task: None Initiation cues: On short final Systems preventing cues: N/A STANDARD: Authority: 60-2 Performance precision: +/- .5 AOA; TD zone 150-1000...precision: +/- .05 AOA; TD Zone 150-1000 Computational accuracy: N/A ... . . ... . ... e e m I TASK NO.: 1.9.4 BEHAVIOR: Perform short field landing

Performance in Object-Choice Aesop's Fable Tasks Are Influenced by Object Biases in New Caledonian Crows but not in Human Children.

PubMed

Miller, Rachael; Jelbert, Sarah A; Taylor, Alex H; Cheke, Lucy G; Gray, Russell D; Loissel, Elsa; Clayton, Nicola S

2016-01-01

The ability to reason about causality underlies key aspects of human cognition, but the extent to which non-humans understand causality is still largely unknown. The Aesop's Fable paradigm, where objects are inserted into water-filled tubes to obtain out-of-reach rewards, has been used to test casual reasoning in birds and children. However, success on these tasks may be influenced by other factors, specifically, object preferences present prior to testing or arising during pre-test stone-dropping training. Here, we assessed this 'object-bias' hypothesis by giving New Caledonian crows and 5-10 year old children two object-choice Aesop's Fable experiments: sinking vs. floating objects, and solid vs. hollow objects. Before each test, we assessed subjects' object preferences and/or trained them to prefer the alternative object. Both crows and children showed pre-test object preferences, suggesting that birds in previous Aesop's Fable studies may also have had initial preferences for objects that proved to be functional on test. After training to prefer the non-functional object, crows, but not children, performed more poorly on these two object-choice Aesop's Fable tasks than subjects in previous studies. Crows dropped the non-functional objects into the tube on their first trials, indicating that, unlike many children, they do not appear to have an a priori understanding of water displacement. Alternatively, issues with inhibition could explain their performance. The crows did, however, learn to solve the tasks over time. We tested crows further to determine whether their eventual success was based on learning about the functional properties of the objects, or associating dropping the functional object with reward. Crows inserted significantly more rewarded, non-functional objects than non-rewarded, functional objects. These findings suggest that the ability of New Caledonian crows to produce performances rivaling those of young children on object-choice Aesop's Fable tasks is partly due to pre-existing object preferences.

Broad attention to multiple individual objects may facilitate change detection with complex auditory scenes.

PubMed

Irsik, Vanessa C; Vanden Bosch der Nederlanden, Christina M; Snyder, Joel S

2016-11-01

Attention and other processing constraints limit the perception of objects in complex scenes, which has been studied extensively in the visual sense. We used a change deafness paradigm to examine how attention to particular objects helps and hurts the ability to notice changes within complex auditory scenes. In a counterbalanced design, we examined how cueing attention to particular objects affected performance in an auditory change-detection task through the use of valid or invalid cues and trials without cues (Experiment 1). We further examined how successful encoding predicted change-detection performance using an object-encoding task and we addressed whether performing the object-encoding task along with the change-detection task affected performance overall (Experiment 2). Participants had more error for invalid compared to valid and uncued trials, but this effect was reduced in Experiment 2 compared to Experiment 1. When the object-encoding task was present, listeners who completed the uncued condition first had less overall error than those who completed the cued condition first. All participants showed less change deafness when they successfully encoded change-relevant compared to irrelevant objects during valid and uncued trials. However, only participants who completed the uncued condition first also showed this effect during invalid cue trials, suggesting a broader scope of attention. These findings provide converging evidence that attention to change-relevant objects is crucial for successful detection of acoustic changes and that encouraging broad attention to multiple objects is the best way to reduce change deafness. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

When do chronic differences in self-regulation count? Regulatory focus effects in easy and difficult soccer tasks.

PubMed

Vogel, Tobias; Genschow, Oliver

2013-04-01

Research on regulatory focus theory (Higgins, 1997) suggests that performance increases if instructions fit with sportspersons' dispositions. Sportspersons who chronically focus on wins (i.e., promotion-oriented individuals) perform best if instructions frame the objective as a promotion goal (e.g., "Try to hit!"). By contrast, sportspersons who chronically focus on losses (i.e., prevention-oriented individuals) perform best if instructions frame the objective as a prevention goal (e.g., "Try not to miss!"). Recent theorizing also suggests that regulatory focus interacts with task difficulty. In an experiment, we assessed soccer performance as a function of chronic focus, instructional focus, and task difficulty. Results support that task difficulty moderates the effects of fit on performance; fitting instructions to match the sportsperson's chronic regulatory focus improved performance in the easy rather than the difficult task. Findings are discussed regarding the role of regulatory fit in altering subjective pressure during sports performance.

Persistent spatial information in the FEF during object-based short-term memory does not contribute to task performance.

PubMed

Clark, Kelsey L; Noudoost, Behrad; Moore, Tirin

2014-06-01

We previously reported the existence of a persistent spatial signal in the FEF during object-based STM. This persistent activity reflected the location at which the sample appeared, irrespective of the location of upcoming targets. We hypothesized that such a spatial signal could be used to maintain or enhance object-selective memory activity elsewhere in cortex, analogous to the role of a spatial signal during attention. Here, we inactivated a portion of the FEF with GABAa agonist muscimol to test whether the observed activity contributes to object memory performance. We found that, although RTs were slowed for saccades into the inactivated portion of retinotopic space, performance for samples appearing in that region was unimpaired. This contrasts with the devastating effects of the same FEF inactivation on purely spatial working memory, as assessed with the memory-guided saccade task. Thus, in a task in which a significant fraction of FEF neurons displayed persistent, sample location-based activity, disrupting this activity had no impact on task performance.

Developmental Trends for Object and Spatial Working Memory: A Psychophysiological Analysis

ERIC Educational Resources Information Center

Van Leijenhorst, Linda; Crone, Eveline A.; Van der Molen, Maurits W.

2007-01-01

This study examined developmental trends in object and spatial working memory (WM) using heart rate (HR) to provide an index of covert cognitive processes. Participants in 4 age groups (6-7, 9-10, 11-12, 18-26, n=20 each) performed object and spatial WM tasks, in which each trial was followed by feedback. Spatial WM task performance reached adult…

Cotton-Top Tamarins' ("Saguinus Oedipus") Expectations about Occluded Objects: A Dissociation between Looking and Reaching Tasks

ERIC Educational Resources Information Center

Santos, Laurie R.; Seelig, David; Hauser, Marc D.

2006-01-01

Recent work with human infants and toddlers suggests a dissociation between performance on looking and reaching tasks. Specifically, infants appear to generate accurate representations of occluded objects and their actions when tested in expectancy violation looking tasks but often fail to use this information when reaching for occluded objects.…

Depth rotation and mirror-image reflection reduce affective preference as well as recognition memory for pictures of novel objects.

PubMed

Lawson, Rebecca

2004-10-01

In two experiments, the identification of novel 3-D objects was worse for depth-rotated and mirror-reflected views, compared with the study view in an implicit affective preference memory task, as well as in an explicit recognition memory task. In Experiment 1, recognition was worse and preference was lower when depth-rotated views of an object were paired with an unstudied object relative to trials when the study view of that object was shown. There was a similar trend for mirror-reflected views. In Experiment 2, the study view of an object was both recognized and preferred above chance when it was paired with either depth-rotated or mirror-reflected views of that object. These results suggest that view-sensitive representations of objects mediate performance in implicit, as well as explicit, memory tasks. The findings do not support the claim that separate episodic and structural description representations underlie performance in implicit and explicit memory tasks, respectively.

Frontal lobe activation during object alternation acquisition.

PubMed

Zald, David H; Curtis, Clayton; Chernitsky, Laura A; Pardo, José V

2005-01-01

Object alternation (OA) tasks are increasingly used as probes of ventral prefrontal functioning in humans. In the most common variant of the OA task, subjects must deduce the task rule through trial-and-error learning. To examine the neural correlates of OA acquisition, the authors measured regional cerebral blood flow with positron emission tomography while subjects acquired an OA task, performed a sensorimotor control condition, or performed already learned and practiced OA. As expected, activations emerged in the ventral prefrontal cortex. However, activation of the presupplemental motor area was more closely associated with successful task performance. The authors suggest that areas beyond the ventral prefrontal cortex are critically involved in OA acquisition. 2005 APA

A Correlational Study of Seven Projective Spatial Structures with Regard to the Phases of the MOON^

NASA Astrophysics Data System (ADS)

Wellner, Karen Linette

1995-01-01

This study investigated the relationship between projective spatial structures and the ability to construct a scientific model. In addition, gender-related performance and the influence of prior astronomy experience on task success were evaluated. Sixty-one college science undergraduates were individually administered Piagetian tasks to assess for projective spatial structures and the ability to set up a phases of the moon model. The spatial tasks included: (a) Mountains task (coordination of perspectives); (b) Railroad task (size and intervals of objects with increasing distance); (c) Telephone Poles task (masking and ordering objects); and (d) Shadows task (spatial relationships between an object and its shadow, dependent upon the object's orientation). Cramer coefficient analyses indicated that significant relationships existed between Moon task and spatial task success. In particular, the Shadows task, requiring subjects to draw shadows of objects in different orientations, proved most difficult and was most strongly associated with with a subject's understanding of lunar phases. Chi-square tests for two independent samples were used to analyze gender performance differences on each of the Ave tasks. Males performed significantly better at a.05 significance level in regard to the Shadows task and the Moon task. Chi-square tests for two independent samples showed no significant difference in Moon task performance between subjects with astronomy or Earth science coursework, and those without such science classroom experience. Overall, only six subjects passed all seven projective spatial structure tasks. Piaget (1967) contends that concrete -operational spatial structures must be established before an individual is able to develop formal-operational patterns of thinking. The results of this study indicate that 90% of the interviewed science majors are still operating at the concrete-operational level. Several educational implications were drawn from this study: (1) The teaching of spatially dependent content to students without prerequisite spatial structures results in understanding no further beyond that which can be memorized; (2) assessment for projective spatial structures should precede science lessons dealing with time-space relationships, and (3) a student's level of spatial ability may directly impact upon interpretation of three-dimensional models.

Engineering development of selective agglomeration: Task 5, Bench- scale process testing

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

Not Available

1991-09-01

Under the overall objectives of DOE Contract ``Engineering Development of Selective Agglomeration,`` there were a number of specific objectives in the Task 5 program. The prime objectives of Task 5 are highlighted below: (1) Maximize process performance in pyritic sulfur rejection and BTU recovery, (2) Produce a low ash product, (3) Compare the performance of the heavy agglomerant process based on diesel and the light agglomerant process using heptane, (4) Define optimum processing conditions for engineering design, (5) Provide first-level evaluation of product handleability, and (6) Explore and investigate process options/ideas which may enhance process performance and/or product handleability.

Engineering development of selective agglomeration: Task 5, Bench- scale process testing

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

Not Available

1991-09-01

Under the overall objectives of DOE Contract Engineering Development of Selective Agglomeration,'' there were a number of specific objectives in the Task 5 program. The prime objectives of Task 5 are highlighted below: (1) Maximize process performance in pyritic sulfur rejection and BTU recovery, (2) Produce a low ash product, (3) Compare the performance of the heavy agglomerant process based on diesel and the light agglomerant process using heptane, (4) Define optimum processing conditions for engineering design, (5) Provide first-level evaluation of product handleability, and (6) Explore and investigate process options/ideas which may enhance process performance and/or product handleability.

14- to 16-Month-Olds Attend to Distinct Labels in an Inductive Reasoning Task

PubMed Central

Switzer, Jessica L.; Graham, Susan A.

2017-01-01

We examined how naming objects with unique labels influenced infants’ reasoning about the non-obvious properties of novel objects. Seventy 14- to 16-month-olds participated in an imitation-based inductive inference task during which they were presented with target objects possessing a non-obvious sound property, followed by test objects that varied in shape similarity in comparison to the target. Infants were assigned to one of two groups: a No Label group in which objects were introduced with a general attentional phrase (i.e., “Look at this one”) and a Distinct Label group in which target and test objects were labeled with two distinct count nouns (i.e., fep vs. wug). Infants in the Distinct Label group performed significantly fewer target actions on the high-similarity objects than infants in the No Label group but did not differ in performance of actions on the low-similarity object. Within the Distinct Label group, performance on the inductive inference task was related to age, but not to working memory, inhibitory control, or vocabulary. Within the No Label condition, performance on the inductive inference task was related to a measure of inhibitory control. Our findings suggest that between 14- and 16-months, infants begin to use labels to carve out distinct categories, even when objects are highly perceptually similar. PMID:28484410

Audition and vision share spatial attentional resources, yet attentional load does not disrupt audiovisual integration.

PubMed

Wahn, Basil; König, Peter

2015-01-01

Humans continuously receive and integrate information from several sensory modalities. However, attentional resources limit the amount of information that can be processed. It is not yet clear how attentional resources and multisensory processing are interrelated. Specifically, the following questions arise: (1) Are there distinct spatial attentional resources for each sensory modality? and (2) Does attentional load affect multisensory integration? We investigated these questions using a dual task paradigm: participants performed two spatial tasks (a multiple object tracking task and a localization task), either separately (single task condition) or simultaneously (dual task condition). In the multiple object tracking task, participants visually tracked a small subset of several randomly moving objects. In the localization task, participants received either visual, auditory, or redundant visual and auditory location cues. In the dual task condition, we found a substantial decrease in participants' performance relative to the results of the single task condition. Importantly, participants performed equally well in the dual task condition regardless of the location cues' modality. This result suggests that having spatial information coming from different modalities does not facilitate performance, thereby indicating shared spatial attentional resources for the auditory and visual modality. Furthermore, we found that participants integrated redundant multisensory information similarly even when they experienced additional attentional load in the dual task condition. Overall, findings suggest that (1) visual and auditory spatial attentional resources are shared and that (2) audiovisual integration of spatial information occurs in an pre-attentive processing stage.

Individual strategy ratings improve the control for task difficulty effects in arithmetic problem solving paradigms.

PubMed

Tschentscher, Nadja; Hauk, Olaf

2015-01-01

Mental arithmetic is a powerful paradigm to study problem solving using neuroimaging methods. However, the evaluation of task complexity varies significantly across neuroimaging studies. Most studies have parameterized task complexity by objective features such as the number size. Only a few studies used subjective rating procedures. In fMRI, we provided evidence that strategy self-reports control better for task complexity across arithmetic conditions than objective features (Tschentscher and Hauk, 2014). Here, we analyzed the relative predictive value of self-reported strategies and objective features for performance in addition and multiplication tasks, by using a paradigm designed for neuroimaging research. We found a superiority of strategy ratings as predictor of performance above objective features. In a Principal Component Analysis on reaction times, the first component explained over 90 percent of variance and factor loadings reflected percentages of self-reported strategies well. In multiple regression analyses on reaction times, self-reported strategies performed equally well or better than objective features, depending on the operation type. A Receiver Operating Characteristic (ROC) analysis confirmed this result. Reaction times classified task complexity better when defined by individual ratings. This suggests that participants' strategy ratings are reliable predictors of arithmetic complexity and should be taken into account in neuroimaging research.

Individual strategy ratings improve the control for task difficulty effects in arithmetic problem solving paradigms

PubMed Central

Tschentscher, Nadja; Hauk, Olaf

2015-01-01

Mental arithmetic is a powerful paradigm to study problem solving using neuroimaging methods. However, the evaluation of task complexity varies significantly across neuroimaging studies. Most studies have parameterized task complexity by objective features such as the number size. Only a few studies used subjective rating procedures. In fMRI, we provided evidence that strategy self-reports control better for task complexity across arithmetic conditions than objective features (Tschentscher and Hauk, 2014). Here, we analyzed the relative predictive value of self-reported strategies and objective features for performance in addition and multiplication tasks, by using a paradigm designed for neuroimaging research. We found a superiority of strategy ratings as predictor of performance above objective features. In a Principal Component Analysis on reaction times, the first component explained over 90 percent of variance and factor loadings reflected percentages of self-reported strategies well. In multiple regression analyses on reaction times, self-reported strategies performed equally well or better than objective features, depending on the operation type. A Receiver Operating Characteristic (ROC) analysis confirmed this result. Reaction times classified task complexity better when defined by individual ratings. This suggests that participants’ strategy ratings are reliable predictors of arithmetic complexity and should be taken into account in neuroimaging research. PMID:26321997

What is 3D good for? A review of human performance on stereoscopic 3D displays

NASA Astrophysics Data System (ADS)

McIntire, John P.; Havig, Paul R.; Geiselman, Eric E.

2012-06-01

This work reviews the human factors-related literature on the task performance implications of stereoscopic 3D displays, in order to point out the specific performance benefits (or lack thereof) one might reasonably expect to observe when utilizing these displays. What exactly is 3D good for? Relative to traditional 2D displays, stereoscopic displays have been shown to enhance performance on a variety of depth-related tasks. These tasks include judging absolute and relative distances, finding and identifying objects (by breaking camouflage and eliciting perceptual "pop-out"), performing spatial manipulations of objects (object positioning, orienting, and tracking), and navigating. More cognitively, stereoscopic displays can improve the spatial understanding of 3D scenes or objects, improve memory/recall of scenes or objects, and improve learning of spatial relationships and environments. However, for tasks that are relatively simple, that do not strictly require depth information for good performance, where other strong cues to depth can be utilized, or for depth tasks that lie outside the effective viewing volume of the display, the purported performance benefits of 3D may be small or altogether absent. Stereoscopic 3D displays come with a host of unique human factors problems including the simulator-sickness-type symptoms of eyestrain, headache, fatigue, disorientation, nausea, and malaise, which appear to effect large numbers of viewers (perhaps as many as 25% to 50% of the general population). Thus, 3D technology should be wielded delicately and applied carefully; and perhaps used only as is necessary to ensure good performance.

Imitating actions on objects in early-onset and regressive autism: Effects and implications of task characteristics on performance

PubMed Central

Rogers, Sally J.; Young, Gregory S.; Cook, Ian; Giolzetti, Angelo; Ozonoff, Sally

2010-01-01

This study was designed to examine the nature of object imitation performance in early autism. We hypothesized that imitation would be relatively preserved when behaviors on objects resulted in salient instrumental effects. We designed tasks in which, in one condition, the motor action resulted in a salient, meaningful effect on an object, whereas in the other condition, the same action resulted in a less salient effect because of differing object characteristics. The motor aspects of the tasks did not vary across conditions. Four participant groups of 2- to 5-year-olds were examined: 17 children with early-onset autism, 24 children with regressive onset autism, 22 children with developmental delays, and 22 children with typical development. Groups were matched on nonverbal skills, and differences in verbal development were examined as a moderator of imitative ability. Results revealed an interaction of group by condition, with the combined autism group failing more tasks than the combined comparison groups, and failing more tasks in the less salient condition than in the more salient condition, as hypothesized. Analyses of autism subgroups revealed these effects were primarily because of the regression onset group. Accuracy of motor performance was examined by analyzing errors. Among children passing imitative acts, there were no group differences and no condition effects in the number, type, or pattern of performance errors. Among children passing the tasks, the group with autism did not demonstrate more emulation errors (imitating the goal but not the means) than other groups. There was no evidence that either motor or attentional aspects of the tasks contributed to the poorer imitative performance of the children with autism. PMID:20102648

Validity evidence for the Simulated Colonoscopy Objective Performance Evaluation scoring system.

PubMed

Trinca, Kristen D; Cox, Tiffany C; Pearl, Jonathan P; Ritter, E Matthew

2014-02-01

Low-cost, objective systems to assess and train endoscopy skills are needed. The aim of this study was to evaluate the ability of Simulated Colonoscopy Objective Performance Evaluation to assess the skills required to perform endoscopy. Thirty-eight subjects were included in this study, all of whom performed 4 tasks. The scoring system measured performance by calculating precision and efficiency. Data analysis assessed the relationship between colonoscopy experience and performance on each task and the overall score. Endoscopic trainees' Simulated Colonoscopy Objective Performance Evaluation scores correlated significantly with total colonoscopy experience (r = .61, P = .003) and experience in the past 12 months (r = .63, P = .002). Significant differences were seen among practicing endoscopists, nonendoscopic surgeons, and trainees (P < .0001). When the 4 tasks were analyzed, each showed significant correlation with colonoscopy experience (scope manipulation, r = .44, P = .044; tool targeting, r = .45, P = .04; loop management, r = .47, P = .032; mucosal inspection, r = .65, P = .001) and significant differences in performance between the endoscopist groups, except for mucosal inspection (scope manipulation, P < .0001; tool targeting, P = .002; loop management, P = .0008; mucosal inspection, P = .27). Simulated Colonoscopy Objective Performance Evaluation objectively assesses the technical skills required to perform endoscopy and shows promise as a platform for proficiency-based skills training. Published by Elsevier Inc.

Adaptive strategies of remote systems operators exposed to perturbed camera-viewing conditions

NASA Technical Reports Server (NTRS)

Stuart, Mark A.; Manahan, Meera K.; Bierschwale, John M.; Sampaio, Carlos E.; Legendre, A. J.

1991-01-01

This report describes a preliminary investigation of the use of perturbed visual feedback during the performance of simulated space-based remote manipulation tasks. The primary objective of this NASA evaluation was to determine to what extent operators exhibit adaptive strategies which allow them to perform these specific types of remote manipulation tasks more efficiently while exposed to perturbed visual feedback. A secondary objective of this evaluation was to establish a set of preliminary guidelines for enhancing remote manipulation performance and reducing the adverse effects. These objectives were accomplished by studying the remote manipulator performance of test subjects exposed to various perturbed camera-viewing conditions while performing a simulated space-based remote manipulation task. Statistical analysis of performance and subjective data revealed that remote manipulation performance was adversely affected by the use of perturbed visual feedback and performance tended to improve with successive trials in most perturbed viewing conditions.

Attentional Spreading in Object-Based Attention

ERIC Educational Resources Information Center

Richard, Ashleigh M.; Lee, Hyunkyu; Vecera, Shaun P.

2008-01-01

The authors investigated 2 effects of object-based attention: the spread of attention within an attended object and the prioritization of search across possible target locations within an attended object. Participants performed a flanker task in which the location of the task-relevant target was fixed and known to participants. A spreading…

Preschool physics: Using the invisible property of weight in causal reasoning tasks

PubMed Central

Williamson, Rebecca A.; Meltzoff, Andrew N.

2018-01-01

Causal reasoning is an important aspect of scientific thinking. Even young human children can use causal reasoning to explain observations, make predictions, and design actions to bring about specific outcomes in the physical world. Weight is an interesting type of cause because it is an invisible property. Here, we tested preschool children with causal problem-solving tasks that assessed their understanding of weight. In an experimental setting, 2- to 5-year-old children completed three different tasks in which they had to use weight to produce physical effects—an object displacement task, a balance-scale task, and a tower-building task. The results showed that the children’s understanding of how to use object weight to produce specific object-to-object causal outcomes improved as a function of age, with 4- and 5-year-olds showing above-chance performance on all three tasks. The younger children’s performance was more variable. The pattern of results provides theoretical insights into which aspects of weight processing are particularly difficult for preschool children and why they find it difficult. PMID:29561840

Preschool physics: Using the invisible property of weight in causal reasoning tasks.

PubMed

Wang, Zhidan; Williamson, Rebecca A; Meltzoff, Andrew N

2018-01-01

Causal reasoning is an important aspect of scientific thinking. Even young human children can use causal reasoning to explain observations, make predictions, and design actions to bring about specific outcomes in the physical world. Weight is an interesting type of cause because it is an invisible property. Here, we tested preschool children with causal problem-solving tasks that assessed their understanding of weight. In an experimental setting, 2- to 5-year-old children completed three different tasks in which they had to use weight to produce physical effects-an object displacement task, a balance-scale task, and a tower-building task. The results showed that the children's understanding of how to use object weight to produce specific object-to-object causal outcomes improved as a function of age, with 4- and 5-year-olds showing above-chance performance on all three tasks. The younger children's performance was more variable. The pattern of results provides theoretical insights into which aspects of weight processing are particularly difficult for preschool children and why they find it difficult.

Memory development in the second year: for events or locations?

PubMed

Russell, James; Thompson, Doreen

2003-04-01

We employed an object-placement/object-removal design, inspired by recent work on 'episodic-like' memory in scrub jays (Clayton, N. S., & Dickinson, A. (1998). Episodic-like memory during cache recovery by scrub jays. Nature, 395, 272-274), to examine the possibility that children in the second year of life have event-based memories. In one task, a successful search could have been due to the recall of an object-removal event. In the second task, a successful search could only have been caused by recall of where objects were located. Success was general in the oldest group of children (21-25 months), while performance was broadly similar on the two tasks. The parsimonious interpretation of this outcome is that the first task was performed by location memory, not by event memory. We place these data in the context of object permanence development.

Nonenculturated orangutans' (Pongo pygmaeus) use of experimenter-given manual and facial cues in an object-choice task.

PubMed

Byrnit, Jill T

2004-09-01

Several experiments have been performed, to examine whether nonhuman primates are able to make use of experimenter-given manual and facial (visual) cues to direct their attention to a baited object. Contrary to the performance of prosimians and monkeys, great apes repeatedly have shown task efficiency in experiments such as these. However, many great ape subjects used have been "enculturated" individuals. In the present study, 3 nonenculturated orangutans (Pongo pygmaeus) were tested for their ability to use experimenter-given pointing, gazing, and glancing cues in an object-choice task. All subjects readily made use of the pointing gesture. However, when subjects were left with only gazing or glancing cues, their performance deteriorated markedly, and they were not able to complete the task. ((c) 2004 APA, all rights reserved).

Cognitive domains in the dog: independence of working memory from object learning, selective attention, and motor learning.

PubMed

Zanghi, Brian M; Araujo, Joseph; Milgram, Norton W

2015-05-01

Cognition in dogs, like in humans, is not a unitary process. Some functions, such as simple discrimination learning, are relatively insensitive to age; others, such as visuospatial learning can provide behavioral biomarkers of age. The present experiment sought to further establish the relationship between various cognitive domains, namely visuospatial memory, object discrimination learning (ODL), and selective attention (SA). In addition, we also set up a task to assess motor learning (ML). Thirty-six beagles (9-16 years) performed a variable delay non-matching to position (vDNMP) task using two objects with 20- and 90-s delay and were divided into three groups based on a combined score (HMP = 88-93 % accuracy [N = 12]; MMP = 79-86 % accuracy [N = 12]; LMP = 61-78 % accuracy [N = 12]). Variable object oddity task was used to measure ODL (correct or incorrect object) and SA (0-3 incorrect distractor objects with same [SA-same] or different [SA-diff] correct object as ODL). ML involved reaching various distances (0-15 cm). Age did not differ between memory groups (mean 11.6 years). ODL (ANOVA P = 0.43), or SA-same and SA-different (ANOVA P = 0.96), performance did not differ between the three vDNMP groups, although mean errors during ODL was numerically higher for LMP dogs. Errors increased (P < 0.001) for all dogs with increasing number of distractor objects during both SA tasks. vDNMP groups remained different (ANOVA P < 0.001) when re-tested with vDNMP task 42 days later. Maximum ML distance did not differ between vDNMP groups (ANOVA P = 0.96). Impaired short-term memory performance in aged dogs does not appear to predict performance of cognitive domains associated with object learning, SA, or maximum ML distance.

Achievement of Virtual and Real Objects Using a Short-Term Motor Learning Protocol in People with Duchenne Muscular Dystrophy: A Crossover Randomized Controlled Trial.

PubMed

Massetti, Thais; Fávero, Francis Meire; Menezes, Lilian Del Ciello de; Alvarez, Mayra Priscila Boscolo; Crocetta, Tânia Brusque; Guarnieri, Regiani; Nunes, Fátima L S; Monteiro, Carlos Bandeira de Mello; Silva, Talita Dias da

2018-04-01

To evaluate whether people with Duchenne muscular dystrophy (DMD) practicing a task in a virtual environment could improve performance given a similar task in a real environment, as well as distinguishing whether there is transference between performing the practice in virtual environment and then a real environment and vice versa. Twenty-two people with DMD were evaluated and divided into two groups. The goal was to reach out and touch a red cube. Group A began with the real task and had to touch a real object, and Group B began with the virtual task and had to reach a virtual object using the Kinect system. ANOVA showed that all participants decreased the movement time from the first (M = 973 ms) to the last block of acquisition (M = 783 ms) in both virtual and real tasks and motor learning could be inferred by the short-term retention and transfer task (with increasing distance of the target). However, the evaluation of task performance demonstrated that the virtual task provided an inferior performance when compared to the real task in all phases of the study, and there was no effect for sequence. Both virtual and real tasks promoted improvement of performance in the acquisition phase, short-term retention, and transfer. However, there was no transference of learning between environments. In conclusion, it is recommended that the use of virtual environments for individuals with DMD needs to be considered carefully.

Performance in Object-Choice Aesop’s Fable Tasks Are Influenced by Object Biases in New Caledonian Crows but not in Human Children

PubMed Central

Taylor, Alex H.; Cheke, Lucy G.; Gray, Russell D.; Loissel, Elsa; Clayton, Nicola S.

2016-01-01

The ability to reason about causality underlies key aspects of human cognition, but the extent to which non-humans understand causality is still largely unknown. The Aesop’s Fable paradigm, where objects are inserted into water-filled tubes to obtain out-of-reach rewards, has been used to test casual reasoning in birds and children. However, success on these tasks may be influenced by other factors, specifically, object preferences present prior to testing or arising during pre-test stone-dropping training. Here, we assessed this ‘object-bias’ hypothesis by giving New Caledonian crows and 5–10 year old children two object-choice Aesop’s Fable experiments: sinking vs. floating objects, and solid vs. hollow objects. Before each test, we assessed subjects’ object preferences and/or trained them to prefer the alternative object. Both crows and children showed pre-test object preferences, suggesting that birds in previous Aesop’s Fable studies may also have had initial preferences for objects that proved to be functional on test. After training to prefer the non-functional object, crows, but not children, performed more poorly on these two object-choice Aesop’s Fable tasks than subjects in previous studies. Crows dropped the non-functional objects into the tube on their first trials, indicating that, unlike many children, they do not appear to have an a priori understanding of water displacement. Alternatively, issues with inhibition could explain their performance. The crows did, however, learn to solve the tasks over time. We tested crows further to determine whether their eventual success was based on learning about the functional properties of the objects, or associating dropping the functional object with reward. Crows inserted significantly more rewarded, non-functional objects than non-rewarded, functional objects. These findings suggest that the ability of New Caledonian crows to produce performances rivaling those of young children on object-choice Aesop’s Fable tasks is partly due to pre-existing object preferences. PMID:27936242

Graphics Design Technology Curriculum Guide.

ERIC Educational Resources Information Center

Idaho State Dept. of Education, Boise. Div. of Vocational Education.

This Idaho secondary education curriculum guide provides lists of tasks, performance objectives, and enabling objectives for instruction intended to impart entry-level employment skills in graphics design technology. The first list states all tasks for 11 areas; separate lists for each area follow. Each task on the lists is accompanied by a…

Linguistic Mediation of Children's Performance in a New Symbolic Understanding Task

ERIC Educational Resources Information Center

Homer, Bruce D.; Petroff, Natalya; Hayward, Elizabeth O.

2013-01-01

The effects of language on symbolic functioning were examined using the "boxes task," a new symbolic understanding task based on DeLoache's model task. Children ("N" = 32; ages 2;4--3;8) observed an object being hidden in a stack of four boxes and were then asked to retrieve a similar object in the same location from a set of…

Effects of verbal and nonverbal interference on spatial and object visual working memory.

PubMed

Postle, Bradley R; Desposito, Mark; Corkin, Suzanne

2005-03-01

We tested the hypothesis that a verbal coding mechanism is necessarily engaged by object, but not spatial, visual working memory tasks. We employed a dual-task procedure that paired n-back working memory tasks with domain-specific distractor trials inserted into each interstimulus interval of the n-back tasks. In two experiments, object n-back performance demonstrated greater sensitivity to verbal distraction, whereas spatial n-back performance demonstrated greater sensitivity to motion distraction. Visual object and spatial working memory may differ fundamentally in that the mnemonic representation of featural characteristics of objects incorporates a verbal (perhaps semantic) code, whereas the mnemonic representation of the location of objects does not. Thus, the processes supporting working memory for these two types of information may differ in more ways than those dictated by the "what/where" organization of the visual system, a fact more easily reconciled with a component process than a memory systems account of working memory function.

Effects of verbal and nonverbal interference on spatial and object visual working memory

PubMed Central

POSTLE, BRADLEY R.; D’ESPOSITO, MARK; CORKIN, SUZANNE

2005-01-01

We tested the hypothesis that a verbal coding mechanism is necessarily engaged by object, but not spatial, visual working memory tasks. We employed a dual-task procedure that paired n-back working memory tasks with domain-specific distractor trials inserted into each interstimulus interval of the n-back tasks. In two experiments, object n-back performance demonstrated greater sensitivity to verbal distraction, whereas spatial n-back performance demonstrated greater sensitivity to motion distraction. Visual object and spatial working memory may differ fundamentally in that the mnemonic representation of featural characteristics of objects incorporates a verbal (perhaps semantic) code, whereas the mnemonic representation of the location of objects does not. Thus, the processes supporting working memory for these two types of information may differ in more ways than those dictated by the “what/where” organization of the visual system, a fact more easily reconciled with a component process than a memory systems account of working memory function. PMID:16028575

Spatial discrimination deficits as a function of mnemonic interference in aged adults with and without memory impairment.

PubMed

Reagh, Zachariah M; Roberts, Jared M; Ly, Maria; DiProspero, Natalie; Murray, Elizabeth; Yassa, Michael A

2014-03-01

It is well established that aging is associated with declines in episodic memory. In recent years, an emphasis has emerged on the development of behavioral tasks and the identification of biomarkers that are predictive of cognitive decline in healthy as well as pathological aging. Here, we describe a memory task designed to assess the accuracy of discrimination ability for the locations of objects. Object locations were initially encoded incidentally, and appeared in a single space against a 5 × 7 grid. During retrieval, subjects viewed repeated object-location pairings, displacements of 1, 2, 3, or 4 grid spaces, and maximal corner-to-opposite-corner displacements. Subjects were tasked with judging objects in this second viewing as having retained their original location, or having moved. Performance on a task such as this is thought to rely on the capacity of the individual to perform hippocampus-mediated pattern separation. We report a performance deficit associated with a physically healthy aged group compared to young adults specific to trials with low mnemonic interference. Additionally, for aged adults, performance on the task was correlated with performance on the delayed recall portion of the Rey Auditory Verbal Learning Test (RAVLT), a neuropsychological test sensitive to hippocampal dysfunction. In line with prior work, dividing the aged group into unimpaired and impaired subgroups based on RAVLT Delayed Recall scores yielded clearly distinguishable patterns of performance, with the former subgroup performing comparably to young adults, and the latter subgroup showing generally impaired memory performance even with minimal interference. This study builds on existing tasks used in the field, and contributes a novel paradigm for differentiation of healthy from possible pathological aging, and may thus provide an avenue for early detection of age-related cognitive decline. Copyright © 2013 Wiley Periodicals, Inc.

Objects and events as determinants of parallel processing in dual tasks: evidence from the backward compatibility effect.

PubMed

Ellenbogen, Ravid; Meiran, Nachshon

2011-02-01

The backward-compatibility effect (BCE) is a major index of parallel processing in dual tasks and is related to the dependency of Task 1 performance on Task 2 response codes (Hommel, 1998). The results of four dual-task experiments showed that a BCE occurs when the stimuli of both tasks are included in the same visual object (Experiments 1 and 2) or belong to the same perceptual event (Experiments 3 and 4). Thus, the BCE may be modulated by factors that influence whether both task stimuli are included in the same perceptual event (objects, as studied in cognitive experiments, being special cases of events). As with objects, drawing attention to a (selected) event results in the processing of its irrelevant features and may interfere with task execution. (c) 2010 APA, all rights reserved.

Positive and Negative Consequences of Making Coffee among Breakfast Related Irrelevant Objects: Evidence from MCI, Dementia, and Healthy Ageing.

PubMed

Rodríguez-Bailón, María; García-Morán, Tamara; Montoro-Membila, Nuria; Ródenas-García, Estrella; Montoro, Marisa Arnedo; Funes Molina, María Jesús

2017-07-01

Previous studies have reported impairments in activities of daily living (ADL) performance in the presence of irrelevant but physically/functionally related objects in dementia patients. The aim of the present study was to increase our knowledge about the impact of the presence of contextually related non-target objects on ADL execution in patients with multi-domain mild cognitive impairment (MCI) and dementia. We compared ADL execution in patients with MCI, dementia, and healthy elderly participants under two experimental conditions: One in which the target objects were embedded with contextually related non-target items that constituted the object set necessary to complete two additional (but unrequired) ADL tasks related to the target task, and a second, control condition where target objects were surrounded by isolated objects (they never constituted a whole set needed to complete an alternative ADL task). Separate analysis of ADL errors associated with the target task versus errors involving the non-target objects revealed that, although the presence of contextually related objects facilitated the accomplishment of the target task, such a condition also led to errors involving the use of irrelevant objects in dementia and MCI. The presence of contextually related non-target items produces both positive and negative effects on ADL performance. These types of non-target objects might help to cue the retrieval of the action schema related to the target task, particularly in patients with MCI. In contrast, the presence of these objects might also lead to distraction in dementia and MCI. (JINS, 2017, 23, 481-492).

An exploratory analysis of task-interspersal procedures while teaching object labels to children with autism.

PubMed

Volkert, Valerie M; Lerman, Dorothea C; Trosclair, Nicole; Addison, Laura; Kodak, Tiffany

2008-01-01

Research has demonstrated that interspersing mastered tasks with new tasks facilitates learning under certain conditions; however, little is known about factors that influence the effectiveness of this treatment strategy. The initial purpose of the current investigation was to evaluate the effects of similar versus dissimilar interspersed tasks while teaching object labels to children diagnosed with autism or developmental delays. We then conducted a series of exploratory analyses involving the type of reinforcer delivered for correct responses on trials with unknown or known object labels. Performance was enhanced under the interspersal condition only when either brief praise was delivered for all correct responses or presumably more preferred reinforcers were provided for performance on known trials rather than on unknown trials.

Estrous cycle, pregnancy, and parity enhance performance of rats in object recognition or object placement tasks

PubMed Central

Paris, Jason J; Frye, Cheryl A

2008-01-01

Ovarian hormone elevations are associated with enhanced learning/memory. During behavioral estrus or pregnancy, progestins, such as progesterone (P4) and its metabolite 5α-pregnan-3α-ol-20-one (3α,5α-THP), are elevated due, in part, to corpora luteal and placental secretion. During ‘pseudopregnancy’, the induction of corpora luteal functioning results in a hormonal milieu analogous to pregnancy, which ceases after about 12 days, due to the lack of placental formation. Multiparity is also associated with enhanced learning/memory, perhaps due to prior steroid exposure during pregnancy. Given evidence that progestins and/or parity may influence cognition, we investigated how natural alterations in the progestin milieu influence cognitive performance. In Experiment 1, virgin rats (nulliparous) or rats with two prior pregnancies (multiparous) were assessed on the object placement and recognition tasks, when in high-estrogen/P4 (behavioral estrus) or low-estrogen/P4 (diestrus) phases of the estrous cycle. In Experiment 2, primiparous or multiparous rats were tested in the object placement and recognition tasks when not pregnant, pseudopregnant, or pregnant (between gestational days (GDs) 6 and 12). In Experiment 3, pregnant primiparous or multiparous rats were assessed daily in the object placement or recognition tasks. Females in natural states associated with higher endogenous progestins (behavioral estrus, pregnancy, multiparity) outperformed rats in low progestin states (diestrus, non-pregnancy, nulliparity) on the object placement and recognition tasks. In earlier pregnancy, multiparous, compared with primiparous, rats had a lower corticosterone, but higher estrogen levels, concomitant with better object placement performance. From GD 13 until post partum, primiparous rats had higher 3α,5α-THP levels and improved object placement performance compared with multiparous rats. PMID:18390689

Different impairments of semantic cognition in semantic dementia and semantic aphasia: evidence from the non-verbal domain

PubMed Central

Corbett, Faye; Jefferies, Elizabeth; Ehsan, Sheeba

2009-01-01

Disorders of semantic cognition in different neuropsychological conditions result from diverse areas of brain damage and may have different underlying causes. This study used a comparative case-series design to examine the hypothesis that relatively circumscribed bilateral atrophy of the anterior temporal lobe in semantic dementia (SD) produces a gradual degradation of core semantic representations, whilst a deficit of cognitive control produces multi-modal semantic impairment in a subset of patients with stroke aphasia following damage involving the left prefrontal cortex or regions in and around the temporoparietal area; this condition, which transcends traditional aphasia classifications, is referred to as ‘semantic aphasia’ (SA). There have been very few direct comparisons of these patient groups to date and these previous studies have focussed on verbal comprehension. This study used a battery of object-use tasks to extend this line of enquiry into the non-verbal domain for the first time. A group of seven SA patients were identified who failed both word and picture versions of a semantic association task. These patients were compared with eight SD cases. Both groups showed significant deficits in object use but these impairments were qualitatively different. Item familiarity correlated with performance on object-use tasks for the SD group, consistent with the view that core semantic representations are degrading in this condition. In contrast, the SA participants were insensitive to the familiarity of the objects. Further, while the SD patients performed consistently across tasks that tapped different aspects of knowledge and object use for the same items, the performance of the SA participants reflected the control requirements of the tasks. Single object use was relatively preserved in SA but performance on complex mechanical puzzles was substantially impaired. Similarly, the SA patients were able to complete straightforward item matching tasks, such as word-picture matching, but performed more poorly on associative picture-matching tasks, even when the tests involved the same items. The two groups of patients also showed a different pattern of errors in object use. SA patients made substantial numbers of erroneous intrusions in their demonstrations, such as inappropriate object movements. In contrast, response omissions were more common in SD. This study provides converging evidence for qualitatively different impairments of semantic cognition in SD and SA, and uniquely demonstrates this pattern in a non-verbal expressive domain—object use. PMID:19506072

Effect of tDCS on task relevant and irrelevant perceptual learning of complex objects.

PubMed

Van Meel, Chayenne; Daniels, Nicky; de Beeck, Hans Op; Baeck, Annelies

2016-01-01

During perceptual learning the visual representations in the brain are altered, but these changes' causal role has not yet been fully characterized. We used transcranial direct current stimulation (tDCS) to investigate the role of higher visual regions in lateral occipital cortex (LO) in perceptual learning with complex objects. We also investigated whether object learning is dependent on the relevance of the objects for the learning task. Participants were trained in two tasks: object recognition using a backward masking paradigm and an orientation judgment task. During both tasks, an object with a red line on top of it were presented in each trial. The crucial difference between both tasks was the relevance of the object: the object was relevant for the object recognition task, but not for the orientation judgment task. During training, half of the participants received anodal tDCS stimulation targeted at the lateral occipital cortex (LO). Afterwards, participants were tested on how well they recognized the trained objects, the irrelevant objects presented during the orientation judgment task and a set of completely new objects. Participants stimulated with tDCS during training showed larger improvements of performance compared to participants in the sham condition. No learning effect was found for the objects presented during the orientation judgment task. To conclude, this study suggests a causal role of LO in relevant object learning, but given the rather low spatial resolution of tDCS, more research on the specificity of this effect is needed. Further, mere exposure is not sufficient to train object recognition in our paradigm.

Closed-loop, pilot/vehicle analysis of the approach and landing task

NASA Technical Reports Server (NTRS)

Anderson, M. R.; Schmidt, D. K.

1986-01-01

In the case of approach and landing, it is universally accepted that the pilot uses more than one vehicle response, or output, to close his control loops. Therefore, to model this task, a multi-loop analysis technique is required. The analysis problem has been in obtaining reasonable analytic estimates of the describing functions representing the pilot's loop compensation. Once these pilot describing functions are obtained, appropriate performance and workload metrics must then be developed for the landing task. The optimal control approach provides a powerful technique for obtaining the necessary describing functions, once the appropriate task objective is defined in terms of a quadratic objective function. An approach is presented through the use of a simple, reasonable objective function and model-based metrics to evaluate loop performance and pilot workload. The results of an analysis of the LAHOS (Landing and Approach of Higher Order Systems) study performed by R.E. Smith is also presented.

A Catalog of Performance Objectives, Performance Conditions, and Performance Guides for Machine Tool Operations.

ERIC Educational Resources Information Center

Stadt, Ronald; And Others

This catalog provides performance objectives, tasks, standards, and performance guides associated with current occupational information relating to the job content of machinists, specifically tool grinder operators, production lathe operators, and production screw machine operators. The catalog is comprised of 262 performance objectives, tool and…

Are we under-utilizing the talents of primary care personnel? A job analytic examination

PubMed Central

Hysong, Sylvia J; Best, Richard G; Moore, Frank I

2007-01-01

Background Primary care staffing decisions are often made unsystematically, potentially leading to increased costs, dissatisfaction, turnover, and reduced quality of care. This article aims to (1) catalogue the domain of primary care tasks, (2) explore the complexity associated with these tasks, and (3) examine how tasks performed by different job titles differ in function and complexity, using Functional Job Analysis to develop a new tool for making evidence-based staffing decisions. Methods Seventy-seven primary care personnel from six US Department of Veterans Affairs (VA) Medical Centers, representing six job titles, participated in two-day focus groups to generate 243 unique task statements describing the content of VA primary care. Certified job analysts rated tasks on ten dimensions representing task complexity, skills, autonomy, and error consequence. Two hundred and twenty-four primary care personnel from the same clinics then completed a survey indicating whether they performed each task. Tasks were catalogued using an adaptation of an existing classification scheme; complexity differences were tested via analysis of variance. Results Objective one: Task statements were categorized into four functions: service delivery (65%), administrative duties (15%), logistic support (9%), and workforce management (11%). Objective two: Consistent with expectations, 80% of tasks received ratings at or below the mid-scale value on all ten scales. Objective three: Service delivery and workforce management tasks received higher ratings on eight of ten scales (multiple functional complexity dimensions, autonomy, human error consequence) than administrative and logistic support tasks. Similarly, tasks performed by more highly trained job titles received higher ratings on six of ten scales than tasks performed by lower trained job titles. Contrary to expectations, the distribution of tasks across functions did not significantly vary by job title. Conclusion Primary care personnel are not being utilized to the extent of their training; most personnel perform many tasks that could reasonably be performed by personnel with less training. Primary care clinics should use evidence-based information to optimize job-person fit, adjusting clinic staff mix and allocation of work across staff to enhance efficiency and effectiveness. PMID:17397534

V-TECS Guide for Automobile Air Conditioning and Electrical System Technician.

ERIC Educational Resources Information Center

Meyer, Calvin F.; Benson, Robert T.

This curriculum guide provides an outline for an eight-unit course to train automobile air conditioning and electrical system technicians. Each unit focuses on a duty that is composed of a number of performance objectives. For each objective, these materials are provided: a task, a standard of performance of task, source of standard, conditions…

Object properties and cognitive load in the formation of associative memory during precision lifting.

PubMed

Li, Yong; Randerath, Jennifer; Bauer, Hans; Marquardt, Christian; Goldenberg, Georg; Hermsdörfer, Joachim

2009-01-03

When we manipulate familiar objects in our daily life, our grip force anticipates the physical demands right from the moment of contact with the object, indicating the existence of a memory for relevant object properties. This study explores the formation and consolidation of the memory processes that associate either familiar (size) or arbitrary object features (color) with object weight. In the general task, participants repetitively lifted two differently weighted objects (580 and 280 g) in a pseudo-random order. Forty young healthy adults participated in this study and were randomly distributed into four groups: Color Cue Single task (CCS, blue and red, 9.8(3)cm(3)), Color Cue Dual task (CCD), No Cue (NC) and Size Cue (SC, 9.8(3) and 6(3)cm(3)) group. All groups performed a repetitive precision grasp-lift task and were retested with the same protocol after a 5-min pause. The CCD group was also required to simultaneously perform a memory task during each lift of differently weighted objects coded by color. The results show that groups lifting objects with arbitrary or familiar features successfully formed the association between object weight and manipulated object features and incorporated this into grip force programming, as observed in the different scaling of grip force and grip force rate for different object weights. An arbitrary feature, i.e., color, can be sufficiently associated with object weight, however with less strength than the familiar feature of size. The simultaneous memory task impaired anticipatory force scaling during repetitive object lifting but did not jeopardize the learning process and the consolidation of the associative memory.

Object-based and egocentric mental rotation performance in older adults: the importance of gender differences and motor ability.

PubMed

Jansen, Petra; Kaltner, Sandra

2014-01-01

In this study, mental rotation performance was assessed in both an object-based task, human figures and letters as stimuli, and in an egocentric-based task, a human figure as a stimulus, in 60 older persons between 60 and 71 years old (30 women, 30 men). Additionally all participants completed three motor tests measuring balance and mobility. The results show that the reaction time was slower for letters than for both human figure tasks and the mental rotation speed was faster over all for egocentric mental rotation tasks. Gender differences were found in the accuracy measurement, favoring males, and were independent of stimulus type, kind of transformation, and angular disparity. Furthermore, a regression analysis showed that the accuracy rate for object-based transformations with body stimuli could be predicted by gender and balance ability. This study showed that the mental rotation performance in older adults depends on stimulus type, kind of transformation, and gender and that performance partially relates to motor ability.

Short-Term Memory Maintenance of Object Locations during Active Navigation: Which Working Memory Subsystem Is Essential?

PubMed Central

Baumann, Oliver; Skilleter, Ashley J.; Mattingley, Jason B.

2011-01-01

The goal of the present study was to examine the extent to which working memory supports the maintenance of object locations during active spatial navigation. Participants were required to navigate a virtual environment and to encode the location of a target object. In the subsequent maintenance period they performed one of three secondary tasks that were designed to selectively load visual, verbal or spatial working memory subsystems. Thereafter participants re-entered the environment and navigated back to the remembered location of the target. We found that while navigation performance in participants with high navigational ability was impaired only by the spatial secondary task, navigation performance in participants with poor navigational ability was impaired equally by spatial and verbal secondary tasks. The visual secondary task had no effect on navigation performance. Our results extend current knowledge by showing that the differential engagement of working memory subsystems is determined by navigational ability. PMID:21629686

Adult age differences in subjective and objective measures of strategy use on a sequentially cued prediction task

PubMed Central

Seaman, Kendra L.; Howard, Darlene V.; Howard, James H.

2015-01-01

Differences in strategy use are thought to underlie age-related performance deficits on many learning and decision-making tasks. Recently, age-related differences in learning to make predictions were reported on the Triplets Prediction Task (TPT; Seaman, Howard & Howard, 2013). Notably, deficits appeared early in training and continued with experience. To assess if age differences were due to early strategy use, neural networks were used to objectively assess the strategies implemented by participants during Session 1. Then the relationship between these strategies and performance was examined. Results revealed that older adults were more likely to implement a disadvantageous strategy early in learning, and this led to poorer task performance. Importantly the relationship between age and task performance was partially mediated by early strategy use, suggesting that early strategy selection played a role in the lower quality of predictions in older adults. PMID:24673615

Holistic rubric vs. analytic rubric for measuring clinical performance levels in medical students.

PubMed

Yune, So Jung; Lee, Sang Yeoup; Im, Sun Ju; Kam, Bee Sung; Baek, Sun Yong

2018-06-05

Task-specific checklists, holistic rubrics, and analytic rubrics are often used for performance assessments. We examined what factors evaluators consider important in holistic scoring of clinical performance assessment, and compared the usefulness of applying holistic and analytic rubrics respectively, and analytic rubrics in addition to task-specific checklists based on traditional standards. We compared the usefulness of a holistic rubric versus an analytic rubric in effectively measuring the clinical skill performances of 126 third-year medical students who participated in a clinical performance assessment conducted by Pusan National University School of Medicine. We conducted a questionnaire survey of 37 evaluators who used all three evaluation methods-holistic rubric, analytic rubric, and task-specific checklist-for each student. The relationship between the scores on the three evaluation methods was analyzed using Pearson's correlation. Inter-rater agreement was analyzed by Kappa index. The effect of holistic and analytic rubric scores on the task-specific checklist score was analyzed using multiple regression analysis. Evaluators perceived accuracy and proficiency to be major factors in objective structured clinical examinations evaluation, and history taking and physical examination to be major factors in clinical performance examinations evaluation. Holistic rubric scores were highly related to the scores of the task-specific checklist and analytic rubric. Relatively low agreement was found in clinical performance examinations compared to objective structured clinical examinations. Meanwhile, the holistic and analytic rubric scores explained 59.1% of the task-specific checklist score in objective structured clinical examinations and 51.6% in clinical performance examinations. The results show the usefulness of holistic and analytic rubrics in clinical performance assessment, which can be used in conjunction with task-specific checklists for more efficient evaluation.

Age- and sex-related disturbance in a battery of sensorimotor and cognitive tasks in Kunming mice.

PubMed

Chen, Gui-Hai; Wang, Yue-Ju; Zhang, Li-Qun; Zhou, Jiang-Ning

2004-12-15

A battery of tasks, i.e. beam walking, open field, tightrope, radial six-arm water maze (RAWM), novel-object recognition and olfactory discrimination, was used to determine whether there was age- and sex-related memory deterioration in Kunming (KM) mice, and whether these tasks are independent or correlated with each other. Two age groups of KM mice were used: a younger group (7-8 months old, 12 males and 11 females) and an older group (17-18 months old, 12 males and 12 females). The results showed that the spatial learning ability and memory in the RAWM were lower in older female KM mice relative to younger female mice and older male mice. Consistent with this, in the novel-object recognition task, a non-spatial cognitive task, older female mice but not older male mice had impairment of short-term memory. In olfactory discrimination, another non-spatial task, the older mice retained this ability. Interestingly, female mice performed better than males, especially in the younger group. The older females exhibited sensorimotor impairment in the tightrope task and low locomotor activity in the open-field task. Moreover, older mice spent a longer time in the peripheral squares of the open-field than younger ones. The non-spatial cognitive performance in the novel-object recognition and olfactory discrimination tasks was related to performance in the open-field, whereas the spatial cognitive performance in the RAWM was not related to performance in any of the three sensorimotor tasks. These results suggest that disturbance of spatial learning and memory, as well as selective impairment of non-spatial learning and memory, existed in older female KM mice.

Sympathetic nervous system activity measured by skin conductance quantifies the challenge of walking adaptability tasks after stroke.

PubMed

Clark, David J; Chatterjee, Sudeshna A; McGuirk, Theresa E; Porges, Eric C; Fox, Emily J; Balasubramanian, Chitralakshmi K

2018-02-01

Walking adaptability tasks are challenging for people with motor impairments. The construct of perceived challenge is typically measured by self-report assessments, which are susceptible to subjective measurement error. The development of an objective physiologically-based measure of challenge may help to improve the ability to assess this important aspect of mobility function. The objective of this study to investigate the use of sympathetic nervous system (SNS) activity measured by skin conductance to gauge the physiological stress response to challenging walking adaptability tasks in people post-stroke. Thirty adults with chronic post-stroke hemiparesis performed a battery of seventeen walking adaptability tasks. SNS activity was measured by skin conductance from the palmar surface of each hand. The primary outcome variable was the percent change in skin conductance level (ΔSCL) between the baseline resting and walking phases of each task. Task difficulty was measured by performance speed and by physical therapist scoring of performance. Walking function and balance confidence were measured by preferred walking speed and the Activities-specific Balance Confidence Scale, respectively. There was a statistically significant negative association between ΔSCL and task performance speed and between ΔSCL and clinical score, indicating that tasks with greater SNS activity had slower performance speed and poorer clinical scores. ΔSCL was significantly greater for low functioning participants versus high functioning participants, particularly during the most challenging walking adaptability tasks. This study supports the use of SNS activity measured by skin conductance as a valuable approach for objectively quantifying the perceived challenge of walking adaptability tasks in people post-stroke. Published by Elsevier B.V.

Sympathetic nervous system activity measured by skin conductance quantifies the challenge of walking adaptability tasks after stroke

PubMed Central

Clark, David J.; Chatterjee, Sudeshna A.; McGuirk, Theresa E.; Porges, Eric C.; Fox, Emily J.; Balasubramanian, Chitralakshmi K.

2018-01-01

Background Walking adaptability tasks are challenging for people with motor impairments. The construct of perceived challenge is typically measured by self-report assessments, which are susceptible to subjective measurement error. The development of an objective physiologically-based measure of challenge may help to improve the ability to assess this important aspect of mobility function. The objective of this study to investigate the use of sympathetic nervous system (SNS) activity measured by skin conductance to gauge the physiological stress response to challenging walking adaptability tasks in people post-stroke. Methods Thirty adults with chronic post-stroke hemiparesis performed a battery of seventeen walking adaptability tasks. SNS activity was measured by skin conductance from the palmar surface of each hand. The primary outcome variable was the percent change in skin conductance level (ΔSCL) between the baseline resting and walking phases of each task. Task difficulty was measured by performance speed and by physical therapist grading of performance. Walking function and balance confidence were measured by preferred walking speed and the Activities Specific Balance Confidence Scale, respectively. Results There was a statistically significant negative association between ΔSCL and task performance speed and between ΔSCL and clinical score, indicating that tasks with greater SNS activity had slower performance speed and poorer clinical scores. ΔSCL was significantly greater for low functioning participants versus high functioning participants, particularly during the most challenging walking adaptability tasks. Conclusion This study supports the use of SNS activity measured by skin conductance as a valuable approach for objectively quantifying the perceived challenge of walking adaptability tasks in people post-stroke. PMID:29216598

Deletion of the GluA1 AMPA receptor subunit impairs recency-dependent object recognition memory

PubMed Central

Sanderson, David J.; Hindley, Emma; Smeaton, Emily; Denny, Nick; Taylor, Amy; Barkus, Chris; Sprengel, Rolf; Seeburg, Peter H.; Bannerman, David M.

2011-01-01

Deletion of the GluA1 AMPA receptor subunit impairs short-term spatial recognition memory. It has been suggested that short-term recognition depends upon memory caused by the recent presentation of a stimulus that is independent of contextual–retrieval processes. The aim of the present set of experiments was to test whether the role of GluA1 extends to nonspatial recognition memory. Wild-type and GluA1 knockout mice were tested on the standard object recognition task and a context-independent recognition task that required recency-dependent memory. In a first set of experiments it was found that GluA1 deletion failed to impair performance on either of the object recognition or recency-dependent tasks. However, GluA1 knockout mice displayed increased levels of exploration of the objects in both the sample and test phases compared to controls. In contrast, when the time that GluA1 knockout mice spent exploring the objects was yoked to control mice during the sample phase, it was found that GluA1 deletion now impaired performance on both the object recognition and the recency-dependent tasks. GluA1 deletion failed to impair performance on a context-dependent recognition task regardless of whether object exposure in knockout mice was yoked to controls or not. These results demonstrate that GluA1 is necessary for nonspatial as well as spatial recognition memory and plays an important role in recency-dependent memory processes. PMID:21378100

System engineering techniques for establishing balanced design and performance guidelines for the advanced telerobotic testbed

NASA Technical Reports Server (NTRS)

Zimmerman, W. F.; Matijevic, J. R.

1987-01-01

Novel system engineering techniques have been developed and applied to establishing structured design and performance objectives for the Telerobotics Testbed that reduce technical risk while still allowing the testbed to demonstrate an advancement in state-of-the-art robotic technologies. To estblish the appropriate tradeoff structure and balance of technology performance against technical risk, an analytical data base was developed which drew on: (1) automation/robot-technology availability projections, (2) typical or potential application mission task sets, (3) performance simulations, (4) project schedule constraints, and (5) project funding constraints. Design tradeoffs and configuration/performance iterations were conducted by comparing feasible technology/task set configurations against schedule/budget constraints as well as original program target technology objectives. The final system configuration, task set, and technology set reflected a balanced advancement in state-of-the-art robotic technologies, while meeting programmatic objectives and schedule/cost constraints.

Grip force control in individuals with multiple sclerosis.

PubMed

Iyengar, Veena; Santos, Marcio J; Ko, Michael; Aruin, Alexander S

2009-10-01

Appropriate regulation of grip force is essential in performance of various activities of daily living such as drinking, eating, buttoning a shirt, and so on. The extent to which individuals with multiple sclerosis (MS) are able to regulate grip forces while performing elements of the activities of daily living is largely unknown. . To investigate how individuals with MS control grip force during performance of functional tasks. . This study evaluated the grip force control in selected individuals with MS (n = 9) and healthy control subjects (n = 9) while they performed the task of lifting and placing an instrumented object on a shelf and the task of lifting the object and bringing it close to the mouth to mimic drinking. The grip forces, object acceleration, force ratio, and time lag were recorded and analyzed. . The individuals with MS used significantly larger peak grip force and force ratio than control subjects while performing both tasks and for both hands. In addition, the time lag between the peaks of grip and load forces was significantly longer in individuals with MS. . The application of excessive grip force could predispose individuals with MS to additional fatigue and musculoskeletal overuse trauma. Rehabilitation protocols for the MS population may need to account for increased levels of grip force applied during the performance of functional tasks.

Attentional load inhibits vection.

PubMed

Seno, Takeharu; Ito, Hiroyuki; Sunaga, Shoji

2011-07-01

In this study, we examined the effects of cognitive task performance on the induction of vection. We hypothesized that, if vection requires attentional resources, performing cognitive tasks requiring attention should inhibit or weaken it. Experiment 1 tested the effects on vection of simultaneously performing a rapid serial visual presentation (RSVP) task. The results revealed that the RSVP task affected the subjective strength of vection. Experiment 2 tested the effects of a multiple-object-tracking (MOT) task on vection. Simultaneous performance of the MOT task decreased the duration and subjective strength of vection. Taken together, these findings suggest that vection induction requires attentional resources.

Scene Configuration and Object Reliability Affect the Use of Allocentric Information for Memory-Guided Reaching

PubMed Central

Klinghammer, Mathias; Blohm, Gunnar; Fiehler, Katja

2017-01-01

Previous research has shown that egocentric and allocentric information is used for coding target locations for memory-guided reaching movements. Especially, task-relevance determines the use of objects as allocentric cues. Here, we investigated the influence of scene configuration and object reliability as a function of task-relevance on allocentric coding for memory-guided reaching. For that purpose, we presented participants images of a naturalistic breakfast scene with five objects on a table and six objects in the background. Six of these objects served as potential reach-targets (= task-relevant objects). Participants explored the scene and after a short delay, a test scene appeared with one of the task-relevant objects missing, indicating the location of the reach target. After the test scene vanished, participants performed a memory-guided reaching movement toward the target location. Besides removing one object from the test scene, we also shifted the remaining task-relevant and/or task-irrelevant objects left- or rightwards either coherently in the same direction or incoherently in opposite directions. By varying object coherence, we manipulated the reliability of task-relevant and task-irrelevant objects in the scene. In order to examine the influence of scene configuration (distributed vs. grouped arrangement of task-relevant objects) on allocentric coding, we compared the present data with our previously published data set (Klinghammer et al., 2015). We found that reaching errors systematically deviated in the direction of object shifts, but only when the objects were task-relevant and their reliability was high. However, this effect was substantially reduced when task-relevant objects were distributed across the scene leading to a larger target-cue distance compared to a grouped configuration. No deviations of reach endpoints were observed in conditions with shifts of only task-irrelevant objects or with low object reliability irrespective of task-relevancy. Moreover, when solely task-relevant objects were shifted incoherently, the variability of reaching endpoints increased compared to coherent shifts of task-relevant objects. Our results suggest that the use of allocentric information for coding targets for memory-guided reaching depends on the scene configuration, in particular the average distance of the reach target to task-relevant objects, and the reliability of task-relevant allocentric information. PMID:28450826

Scene Configuration and Object Reliability Affect the Use of Allocentric Information for Memory-Guided Reaching.

PubMed

Klinghammer, Mathias; Blohm, Gunnar; Fiehler, Katja

2017-01-01

Previous research has shown that egocentric and allocentric information is used for coding target locations for memory-guided reaching movements. Especially, task-relevance determines the use of objects as allocentric cues. Here, we investigated the influence of scene configuration and object reliability as a function of task-relevance on allocentric coding for memory-guided reaching. For that purpose, we presented participants images of a naturalistic breakfast scene with five objects on a table and six objects in the background. Six of these objects served as potential reach-targets (= task-relevant objects). Participants explored the scene and after a short delay, a test scene appeared with one of the task-relevant objects missing, indicating the location of the reach target. After the test scene vanished, participants performed a memory-guided reaching movement toward the target location. Besides removing one object from the test scene, we also shifted the remaining task-relevant and/or task-irrelevant objects left- or rightwards either coherently in the same direction or incoherently in opposite directions. By varying object coherence, we manipulated the reliability of task-relevant and task-irrelevant objects in the scene. In order to examine the influence of scene configuration (distributed vs. grouped arrangement of task-relevant objects) on allocentric coding, we compared the present data with our previously published data set (Klinghammer et al., 2015). We found that reaching errors systematically deviated in the direction of object shifts, but only when the objects were task-relevant and their reliability was high. However, this effect was substantially reduced when task-relevant objects were distributed across the scene leading to a larger target-cue distance compared to a grouped configuration. No deviations of reach endpoints were observed in conditions with shifts of only task-irrelevant objects or with low object reliability irrespective of task-relevancy. Moreover, when solely task-relevant objects were shifted incoherently, the variability of reaching endpoints increased compared to coherent shifts of task-relevant objects. Our results suggest that the use of allocentric information for coding targets for memory-guided reaching depends on the scene configuration, in particular the average distance of the reach target to task-relevant objects, and the reliability of task-relevant allocentric information.

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).

Task-Driven Optimization of Fluence Field and Regularization for Model-Based Iterative Reconstruction in Computed Tomography.

PubMed

Gang, Grace J; Siewerdsen, Jeffrey H; Stayman, J Webster

2017-12-01

This paper presents a joint optimization of dynamic fluence field modulation (FFM) and regularization in quadratic penalized-likelihood reconstruction that maximizes a task-based imaging performance metric. We adopted a task-driven imaging framework for prospective designs of the imaging parameters. A maxi-min objective function was adopted to maximize the minimum detectability index ( ) throughout the image. The optimization algorithm alternates between FFM (represented by low-dimensional basis functions) and local regularization (including the regularization strength and directional penalty weights). The task-driven approach was compared with three FFM strategies commonly proposed for FBP reconstruction (as well as a task-driven TCM strategy) for a discrimination task in an abdomen phantom. The task-driven FFM assigned more fluence to less attenuating anteroposterior views and yielded approximately constant fluence behind the object. The optimal regularization was almost uniform throughout image. Furthermore, the task-driven FFM strategy redistribute fluence across detector elements in order to prescribe more fluence to the more attenuating central region of the phantom. Compared with all strategies, the task-driven FFM strategy not only improved minimum by at least 17.8%, but yielded higher over a large area inside the object. The optimal FFM was highly dependent on the amount of regularization, indicating the importance of a joint optimization. Sample reconstructions of simulated data generally support the performance estimates based on computed . The improvements in detectability show the potential of the task-driven imaging framework to improve imaging performance at a fixed dose, or, equivalently, to provide a similar level of performance at reduced dose.

Blending of brain-machine interface and vision-guided autonomous robotics improves neuroprosthetic arm performance during grasping.

PubMed

Downey, John E; Weiss, Jeffrey M; Muelling, Katharina; Venkatraman, Arun; Valois, Jean-Sebastien; Hebert, Martial; Bagnell, J Andrew; Schwartz, Andrew B; Collinger, Jennifer L

2016-03-18

Recent studies have shown that brain-machine interfaces (BMIs) offer great potential for restoring upper limb function. However, grasping objects is a complicated task and the signals extracted from the brain may not always be capable of driving these movements reliably. Vision-guided robotic assistance is one possible way to improve BMI performance. We describe a method of shared control where the user controls a prosthetic arm using a BMI and receives assistance with positioning the hand when it approaches an object. Two human subjects with tetraplegia used a robotic arm to complete object transport tasks with and without shared control. The shared control system was designed to provide a balance between BMI-derived intention and computer assistance. An autonomous robotic grasping system identified and tracked objects and defined stable grasp positions for these objects. The system identified when the user intended to interact with an object based on the BMI-controlled movements of the robotic arm. Using shared control, BMI controlled movements and autonomous grasping commands were blended to ensure secure grasps. Both subjects were more successful on object transfer tasks when using shared control compared to BMI control alone. Movements made using shared control were more accurate, more efficient, and less difficult. One participant attempted a task with multiple objects and successfully lifted one of two closely spaced objects in 92 % of trials, demonstrating the potential for users to accurately execute their intention while using shared control. Integration of BMI control with vision-guided robotic assistance led to improved performance on object transfer tasks. Providing assistance while maintaining generalizability will make BMI systems more attractive to potential users. NCT01364480 and NCT01894802 .

Selective involvement of superior frontal cortex during working memory for shapes.

PubMed

Yee, Lydia T S; Roe, Katherine; Courtney, Susan M

2010-01-01

A spatial/nonspatial functional dissociation between the dorsal and ventral visual pathways is well established and has formed the basis of domain-specific theories of prefrontal cortex (PFC). Inconsistencies in the literature regarding prefrontal organization, however, have led to questions regarding whether the nature of the dissociations observed in PFC during working memory are equivalent to those observed in the visual pathways for perception. In particular, the dissociation between dorsal and ventral PFC during working memory for locations versus object identities has been clearly present in some studies but not in others, seemingly in part due to the type of objects used. The current study compared functional MRI activation during delayed-recognition tasks for shape or color, two object features considered to be processed by the ventral pathway for perceptual recognition. Activation for the shape-delayed recognition task was greater than that for the color task in the lateral occipital cortex, in agreement with studies of visual perception. Greater memory-delay activity was also observed, however, in the parietal and superior frontal cortices for the shape than for the color task. Activity in superior frontal cortex was associated with better performance on the shape task. Conversely, greater delay activity for color than for shape was observed in the left anterior insula and this activity was associated with better performance on the color task. These results suggest that superior frontal cortex contributes to performance on tasks requiring working memory for object identities, but it represents different information about those objects than does the ventral frontal cortex.

Visual memory in unilateral spatial neglect: immediate recall versus delayed recognition.

PubMed

Moreh, Elior; Malkinson, Tal Seidel; Zohary, Ehud; Soroker, Nachum

2014-09-01

Patients with unilateral spatial neglect (USN) often show impaired performance in spatial working memory tasks, apart from the difficulty retrieving "left-sided" spatial data from long-term memory, shown in the "piazza effect" by Bisiach and colleagues. This study's aim was to compare the effect of the spatial position of a visual object on immediate and delayed memory performance in USN patients. Specifically, immediate verbal recall performance, tested using a simultaneous presentation of four visual objects in four quadrants, was compared with memory in a later-provided recognition task, in which objects were individually shown at the screen center. Unlike healthy controls, USN patients showed a left-side disadvantage and a vertical bias in the immediate free recall task (69% vs. 42% recall for right- and left-sided objects, respectively). In the recognition task, the patients correctly recognized half of "old" items, and their correct rejection rate was 95.5%. Importantly, when the analysis focused on previously recalled items (in the immediate task), no statistically significant difference was found in the delayed recognition of objects according to their original quadrant of presentation. Furthermore, USN patients were able to recollect the correct original location of the recognized objects in 60% of the cases, well beyond chance level. This suggests that the memory trace formed in these cases was not only semantic but also contained a visuospatial tag. Finally, successful recognition of objects missed in recall trials points to formation of memory traces for neglected contralesional objects, which may become accessible to retrieval processes in explicit memory.

Sex and spatial position effects on object location memory following intentional learning of object identities.

PubMed

Alexander, Gerianne M; Packard, Mark G; Peterson, Bradley S

2002-01-01

Memory for object location relative both to veridical center (left versus right visual hemispace) and to eccentricity (central versus peripheral objects) was measured in 26 males and 25 females using the Silverman and Eals Location Memory Task. A subset of participants (17 males and 13 females) also completed a measure of implicit learning, the mirror-tracing task. No sex differences were observed in memory for object identities. Further, in both sexes, memory for object locations was better for peripherally located objects than for centrally located objects. In contrast to these similarities in female and male task performance, females but not males showed better recovery of object locations in the right compared to the left visual hemispace. Moreover, memory for object locations in the right hemispace was associated with mirror-tracing performance in women but not in men. Together, these data suggest that the processing of object features and object identification in the left cerebral hemisphere may include processing of spatial information that may contribute to superior object location memory in females relative to males.

Automation - Changes in cognitive demands and mental workload

NASA Technical Reports Server (NTRS)

Tsang, Pamela S.; Johnson, Walter W.

1987-01-01

The effect of partial automation on mental workloads in man/machine tasks is investigated experimentally. Subjective workload measures are obtained from six subjects after performance of a task battery comprising two manual (flight-path control, FC, and target acquisition, TA) tasks and one decisionmaking (engine failure, EF) task; the FC task was performed in both a fully manual (altitude and lateral control) mode and in a semiautomated mode (autmatic latitude control). The performance results and subjective evaluations are presented in graphs and characterized in detail. The automation is shown to improve objective performance and lower subjective workload significantly in the combined FC/TA task, but not in the FC task alone or in the FC/EF task.

An Exploratory Analysis of Task-Interspersal Procedures While Teaching Object Labels to Children with Autism

PubMed Central

Volkert, Valerie M; Lerman, Dorothea C; Trosclair, Nicole; Addison, Laura; Kodak, Tiffany

2008-01-01

Research has demonstrated that interspersing mastered tasks with new tasks facilitates learning under certain conditions; however, little is known about factors that influence the effectiveness of this treatment strategy. The initial purpose of the current investigation was to evaluate the effects of similar versus dissimilar interspersed tasks while teaching object labels to children diagnosed with autism or developmental delays. We then conducted a series of exploratory analyses involving the type of reinforcer delivered for correct responses on trials with unknown or known object labels. Performance was enhanced under the interspersal condition only when either brief praise was delivered for all correct responses or presumably more preferred reinforcers were provided for performance on known trials rather than on unknown trials. PMID:18816973

Deficits in object-in-place but not relative recency performance in the APPswe/PS1dE9 mouse model of Alzheimer's disease: Implications for object recognition.

PubMed

Bonardi, Charlotte; Pardon, Marie-Christine; Armstrong, Paul

2016-10-15

Performance was examined on three variants of the spontaneous object recognition (SOR) task, in 5-month old APPswe/PS1dE9 mice and wild-type littermate controls. A deficit was observed in an object-in-place (OIP) task, in which mice are preexposed to four different objects in specific locations, and then at test two of the objects swap locations (Experiment 2). Typically more exploration is seen of the objects which have switched location, which is taken as evidence of a retrieval-generated priming mechanism. However, no significant transgenic deficit was found in a relative recency (RR) task (Experiment 1), in which mice are exposed to two different objects in two separate sample phases, and then tested with both objects. Typically more exploration of the first-presented object is observed, which is taken as evidence of a self-generated priming mechanism. Nor was there any impairment in the simplest variant, the spontaneous object recognition (SOR) task, in which mice are preexposed to one object and then tested with the familiar and a novel object. This was true regardless of whether the sample-test interval was 5min (Experiment 1) or 24h (Experiments 1 and 2). It is argued that SOR performance depends on retrieval-generated priming as well as self-generated priming, and our preliminary evidence suggests that the retrieval-generated priming process is especially impaired in these young transgenic animals. Copyright © 2016 Elsevier B.V. All rights reserved.

Collaborative Radiological Response Planning

DTIC Science & Technology

2013-12-01

280-5500 Standard Form 298 (Rev. 2–89) Prescribed by ANSI Std. 239–18 i THIS PAGE INTENTIONALLY LEFT BLANK ii Approved for public release...critical tasks, under specified conditions and performance standards .”33 Aligned with the central objective of Capabilities-Based Planning, the TCL...affect task performance.36 More specifically, measures and performance criteria describe a standard for how well a task must be performed and on

Young pigs exhibit differential exploratory behavior during novelty preference tasks in response to age, sex, and delay.

PubMed

Fleming, Stephen A; Dilger, Ryan N

2017-03-15

Novelty preference paradigms have been widely used to study recognition memory and its neural substrates. The piglet model continues to advance the study of neurodevelopment, and as such, tasks that use novelty preference will serve especially useful due to their translatable nature to humans. However, there has been little use of this behavioral paradigm in the pig, and previous studies using the novel object recognition paradigm in piglets have yielded inconsistent results. The current study was conducted to determine if piglets were capable of displaying a novelty preference. Herein a series of experiments were conducted using novel object recognition or location in 3- and 4-week-old piglets. In the novel object recognition task, piglets were able to discriminate between novel and sample objects after delays of 2min, 1h, 1 day, and 2 days (all P<0.039) at both ages. Performance was sex-dependent, as females could perform both 1- and 2-day delays (P<0.036) and males could perform the 2-day delay (P=0.008) but not the 1-day delay (P=0.347). Furthermore, 4-week-old piglets and females tended to exhibit greater exploratory behavior compared with males. Such performance did not extend to novel location recognition tasks, as piglets were only able to discriminate between novel and sample locations after a short delay (P>0.046). In conclusion, this study determined that piglets are able to perform the novel object and location recognition tasks at 3-to-4 weeks of age, however performance was dependent on sex, age, and delay. Copyright © 2016 Elsevier B.V. All rights reserved.

The Role of Learning Objectives under the Academic Big Top.

ERIC Educational Resources Information Center

Kelly, Leonard P.

1980-01-01

Likens a circus performer's varied responsibilities to the learning tasks required of undergraduates. Suggests that students' inability to perform many of these tasks results from confusion about instructors' expectations and the appropriateness of various learning strategies to different tasks. Recommends that students be presented with clear…

False Belief Understanding in Cantonese-Speaking Children

ERIC Educational Resources Information Center

Tardif, Twila; Wellman, Henry M.; Cheung, Kar Man

2004-01-01

The present study investigates the performance of 96 Cantonese-speaking three- to five-year-old preschoolers on three false belief tasks--a deceptive object, a change of location, and an unexpected contents task encompassing a variety of task factors. Most importantly, the research examines the possibility that false belief performance depends on…

Performer-centric Interface Design.

ERIC Educational Resources Information Center

McGraw, Karen L.

1995-01-01

Describes performer-centric interface design and explains a model-based approach for conducting performer-centric analysis and design. Highlights include design methodology, including cognitive task analysis; creating task scenarios; creating the presentation model; creating storyboards; proof of concept screens; object models and icons;…

Lateralized effects of categorical and coordinate spatial processing of component parts on the recognition of 3D non-nameable objects.

PubMed

Saneyoshi, Ayako; Michimata, Chikashi

2009-12-01

Participants performed two object-matching tasks for novel, non-nameable objects consisting of geons. For each original stimulus, two transformations were applied to create comparison stimuli. In the categorical transformation, a geon connected to geon A was moved to geon B. In the coordinate transformation, a geon connected to geon A was moved to a different position on geon A. The Categorical task consisted of the original and the categorically transformed objects. The Coordinate task consisted of the original and the coordinately transformed objects. The original object was presented to the central visual field, followed by a comparison object presented to the right or left visual half-fields (RVF and LVF). The results showed an RVF advantage for the Categorical task and an LVF advantage for the Coordinate task. The possibility that categorical and coordinate spatial processing subsystems would be basic computational elements for between- and within-category object recognition was discussed.

Rhinal and Dorsolateral Prefrontal Cortex Lesions Produce Selective Impairments in Object and Spatial Learning and Memory in Canines

PubMed Central

Christie, Lori-Ann; Saunders, Richard C.; Kowalska, Danuta, M.; MacKay, William A.; Head, Elizabeth; Cotman, Carl W.; Milgram, Norton W.

2014-01-01

To examine the effects of rhinal and dorsolateral prefrontal cortex lesions on object and spatial recognition memory in canines, we used a protocol in which both an object (delayed non-matching to sample, or DNMS) and a spatial (delayed non-matching to position or DNMP) recognition task were administered daily. The tasks used similar procedures such that only the type of stimulus information to be remembered differed. Rhinal cortex (RC) lesions produced a selective deficit on the DNMS task, both in retention of the task rules at short delays and in object recognition memory. By contrast, performance on the DNMP task remained intact at both short and long delay intervals in RC animals. Subjects who received dorsolateral prefrontal cortex (dlPFC) lesions were impaired on a spatial task at a short, 5-sec delay, suggesting disrupted retention of the general task rules, however, this impairment was transient; long-term spatial memory performance was unaffected in dlPFC subjects. The present results provide support for the involvement of the RC in object, but not visuospatial, processing and recognition memory, whereas the dlPFC appears to mediate retention of a non-matching rule. These findings support theories of functional specialization within the medial temporal lobe and frontal cortex and suggest that rhinal and dorsolateral prefrontal cortices in canines are functionally similar to analogous regions in other mammals. PMID:18792072

Performance Enhancements Under Dual-task Conditions

NASA Technical Reports Server (NTRS)

Kramer, A. F.; Wickens, C. D.; Donchin, E.

1984-01-01

Research on dual-task performance has been concerned with delineating the antecedent conditions which lead to dual-task decrements. Capacity models of attention, which propose that a hypothetical resource structure underlies performance, have been employed as predictive devices. These models predict that tasks which require different processing resources can be more successfully time shared than tasks which require common resources. The conditions under which such dual-task integrality can be fostered were assessed in a study in which three factors likely to influence the integrality between tasks were manipulated: inter-task redundancy, the physical proximity of tasks and the task relevant objects. Twelve subjects participated in three experimental sessions in which they performed both single and dual-tasks. The primary task was a pursuit step tracking task. The secondary tasks required the discrimination between different intensities or different spatial positions of a stimulus. The results are discussed in terms of a model of dual-task integrality.

A Catalog of Tasks, Performance Objectives, Performance Guides, Tools, and Equipment, Homemaker Human Development.

ERIC Educational Resources Information Center

Watkins, Betty; And Others

This catalog was designed to provide performance objectives and performance guides associated with current occupational information relating to the job of homemaker. The performance objectives and guides were developed following a literature review and a survey of random samples of homemakers in the five participating states (Alabama, Florida,…

Gaze entropy reflects surgical task load.

PubMed

Di Stasi, Leandro L; Diaz-Piedra, Carolina; Rieiro, Héctor; Sánchez Carrión, José M; Martin Berrido, Mercedes; Olivares, Gonzalo; Catena, Andrés

2016-11-01

Task (over-)load imposed on surgeons is a main contributing factor to surgical errors. Recent research has shown that gaze metrics represent a valid and objective index to asses operator task load in non-surgical scenarios. Thus, gaze metrics have the potential to improve workplace safety by providing accurate measurements of task load variations. However, the direct relationship between gaze metrics and surgical task load has not been investigated yet. We studied the effects of surgical task complexity on the gaze metrics of surgical trainees. We recorded the eye movements of 18 surgical residents, using a mobile eye tracker system, during the performance of three high-fidelity virtual simulations of laparoscopic exercises of increasing complexity level: Clip Applying exercise, Cutting Big exercise, and Translocation of Objects exercise. We also measured performance accuracy and subjective rating of complexity. Gaze entropy and velocity linearly increased with increased task complexity: Visual exploration pattern became less stereotyped (i.e., more random) and faster during the more complex exercises. Residents performed better the Clip Applying exercise and the Cutting Big exercise than the Translocation of Objects exercise and their perceived task complexity differed accordingly. Our data show that gaze metrics are a valid and reliable surgical task load index. These findings have potential impacts to improve patient safety by providing accurate measurements of surgeon task (over-)load and might provide future indices to assess residents' learning curves, independently of expensive virtual simulators or time-consuming expert evaluation.

A Study of Self and Task Performance in Childcare Centres as Perceived by Caregivers under Local Administrative Organisations in Thailand

ERIC Educational Resources Information Center

Bhulpat, Cheerapan

2011-01-01

The purpose of this research was to study the opinions toward self and task performance in childcare centres as perceived by caregivers under the jurisdiction of the Local Administrative Organization. The four areas evaluated were caregiver characteristics, task performance, objectives of caregiving and educating young children and problems and…

Effect of time span and task load on pilot mental workload

NASA Technical Reports Server (NTRS)

Berg, S. L.; Sheridan, T. B.

1986-01-01

Two sets of simulations designed to examine how a pilot's mental workload is affected by continuous manual-control activity versus discrete mental tasks that included the length of time between receiving an assignment and executing it are described. The first experiment evaluated two types of measures: objective performance indicators and subjective ratings. Subjective ratings for the two missions were different, but the objective performance measures were similar. In the second experiments, workload levels were increased and a second performance measure was taken. Mental workload had no influence on either performance-based workload measure. Subjective ratings discriminated among the scenarios and correlated with performance measures for high-workload flights. The number of mental tasks performed did not influence error rates, although high manual workloads did increase errors.

Neural correlates of working memory performance in primary insomnia.

PubMed

Drummond, Sean P A; Walker, Matthew; Almklov, Erin; Campos, Manuel; Anderson, Dane E; Straus, Laura D

2013-09-01

To examine neural correlates of working memory performance in patients with primary insomnia (PIs) compared with well-matched good sleepers (GSs). Twenty-five PIs and 25 GSs underwent functional MRI while performing an N-back working memory task. VA hospital sleep laboratory and University-based functional imaging center. 25 PIs, 25 GSs. N/A. Although PIs did not differ from GSs in cognitive performance, PIs showed the expected differences from GSs in both self-reported and objective sleep measures. PIs, relative to GSs, showed reduced activation of task-related working memory regions. This manifested both as an overall reduction in activation of task-related regions and specifically as reduced modulation of right dorsolateral prefrontal cortex with increasing task difficulty. Similarly, PIs showed reduced modulation (i.e., reduced deactivation) of default mode regions with increasing task difficulty, relative to GSs. However, PIs showed intact performance. These data establish a profile of abnormal neural function in primary insomnia, reflected both in reduced engagement of task-appropriate brain regions and an inability to modulate task-irrelevant (i.e., default mode) brain areas during working memory performance. These data have implications for better understanding the neuropathophysiology of the well established, yet little understood, discrepancy between ubiquitous subjective cognitive complaints in primary insomnia and the rarely found objective deficits during testing.

Sex differences in young children's use of tools in a problem-solving task : The role of object-oriented play.

PubMed

Gredlein, Jeffrey M; Bjorklund, David F

2005-06-01

Three-year-old children were observed in two free-play sessions and participated in a toy-retrieval task, in which only one of six tools could be used to retrieve an out-of-reach toy. Boys engaged in more object-oriented play than girls and were more likely to use tools to retrieve the toy during the baseline tool-use task. All children who did not retrieve the toy during the baseline trials did so after being given a hint, and performance on a transfer-of-training tool-use task approached ceiling levels. This suggests that the sex difference in tool use observed during the baseline phase does not reflect a difference in competency, but rather a sex difference in motivation to interact with objects. Amount of time boys, but not girls, spent in object-oriented play during the free-play sessions predicted performance on the tool-use task. The findings are interpreted in terms of evolutionary theory, consistent with the idea that boys' and girls' play styles evolved to prepare them for adult life in traditional environments.

Two Trackers Are Better than One: Information about the Co-actor's Actions and Performance Scores Contribute to the Collective Benefit in a Joint Visuospatial Task.

PubMed

Wahn, Basil; Kingstone, Alan; König, Peter

2017-01-01

When humans collaborate, they often distribute task demands in order to reach a higher performance compared to performing the same task alone (i.e., a collective benefit). Here, we tested to what extent receiving information about the actions of a co-actor, performance scores, or receiving both types of information impacts the collective benefit in a collaborative multiple object tracking task. In a between-subject design, pairs of individuals jointly tracked a subset of target objects among several moving distractor objects on a computer screen for a 100 trials. At the end of a trial, pairs received performance scores (Experiment 1), information about their partner's target selections (Experiment 2), or both types of information (Experiment 3). In all experiments, the performance of the pair exceeded the individual performances and the simulated performance of two independent individuals combined. Initially, when receiving both types of information (Experiment 3), pairs achieved the highest performance and divided task demands most efficiently compared to the other two experiments. Over time, performances and the ability to divide task demands for pairs receiving a single type of information converged with those receiving both, suggesting that pairs' coordination strategies become equally effective over time across experiments. However, pairs' performances never reached a theoretical limit of performance in all experiments. For distributing task demands, members of a pair predominantly used a left-right division of labor strategy (i.e., the leftmost targets were tracked by one co-actor while the rightmost targets were tracked by the other co-actor). Overall, findings of the present study suggest that receiving information about actions of a co-actor, performance scores, or receiving both enables pairs to devise effective division of labor strategies in a collaborative visuospatial task. However, when pairs had both types of information available, the formation of division of labor strategies was facilitated, indicating that pairs benefited the most from having both types of information available (i.e., actions about the co-actor and performance scores). Findings are applicable to circumstances in which humans need to perform collaborative visuospatial tasks that are time-critical and/or only allow a very limited exchange of information between co-actors.

Spatial coding of object typical size: evidence for a SNARC-like effect.

PubMed

Sellaro, Roberta; Treccani, Barbara; Job, Remo; Cubelli, Roberto

2015-11-01

The present study aimed to assess whether the representation of the typical size of objects can interact with response position codes in two-choice bimanual tasks, and give rise to a SNARC-like effect (faster responses when the representation of the typical size of the object to which the target stimulus refers corresponds to response side). Participants performed either a magnitude comparison task (in which they were required to judge whether the target was smaller or larger than a reference stimulus; Experiment 1) or a semantic decision task (in which they had to classify the target as belonging to either the category of living or non-living entities; Experiment 2). Target stimuli were pictures or written words referring to either typically large and small animals or inanimate objects. In both tasks, participants responded by pressing a left- or right-side button. Results showed that, regardless of the to-be-performed task (magnitude comparison or semantic decision) and stimulus format (picture or word), left responses were faster when the target represented typically small-sized entities, whereas right responses were faster for typically large-sized entities. These results provide evidence that the information about the typical size of objects is activated even if it is not requested by the task, and are consistent with the idea that objects' typical size is automatically spatially coded, as has been proposed to occur for number magnitudes. In this representation, small objects would be on the left and large objects would be on the right. Alternative interpretations of these results are also discussed.

Multi-attribute subjective evaluations of manual tracking tasks vs. objective performance of the human operator

NASA Technical Reports Server (NTRS)

Siapkaras, A.

1977-01-01

A computational method to deal with the multidimensional nature of tracking and/or monitoring tasks is developed. Operator centered variables, including the operator's perception of the task, are considered. Matrix ratings are defined based on multidimensional scaling techniques and multivariate analysis. The method consists of two distinct steps: (1) to determine the mathematical space of subjective judgements of a certain individual (or group of evaluators) for a given set of tasks and experimental conditionings; and (2) to relate this space with respect to both the task variables and the objective performance criteria used. Results for a variety of second-order trackings with smoothed noise-driven inputs indicate that: (1) many of the internally perceived task variables form a nonorthogonal set; and (2) the structure of the subjective space varies among groups of individuals according to the degree of familiarity they have with such tasks.

Vehicle-based countermeasures for signal and stop sign violations. Task 1, Intersection control violation crash analyses. Task 2, Top-level system and human factors requirements

DOT National Transportation Integrated Search

2004-03-01

The report provides the first two major task reports for a study to develop performance specifications and perform supporting objective tests for a planned field operational test (FOT) of a vehicle-based countermeasure to intersection crashes associa...

Skylab task and work performance /Experiment M-151 - Time and motion study/

NASA Technical Reports Server (NTRS)

Kubis, J. F.; Mclaughlin, E. J.

1975-01-01

The primary objective of Experiment M151 was to study the inflight adaptation of Skylab crewmen to a variety of task situations involving different types of activity. A parallel objective was to examine astronaut inflight performance for any behavioral stress effects associated with the working and living conditions of the Skylab environment. Training data provided the basis for comparison of preflight and inflight performance. Efficiency was evaluated through the adaptation function, namely, the relation of performance time over task trials. The results indicate that the initial changeover from preflight to inflight was accompanied by a substantial increase in performance time for most work and task activities. Equally important was the finding that crewmen adjusted rapidly to the weightless environment and became proficient in developing techniques with which to optimize task performance. By the end of the second inflight trial, most of the activities were performed almost as efficiently as on the last preflight trial. The analysis demonstrated the sensitivity of the adaptation function to differences in task and hardware configurations. The function was found to be more regular and less variable inflight than preflight. Translation and control of masses were accomplished easily and efficiently through the rapid development of the arms and legs as subtle guidance and restraint systems.

Autobody Technology Curriculum Guide.

ERIC Educational Resources Information Center

Idaho State Dept. of Education, Boise. Div. of Vocational Education.

This Idaho state curriculum guide provides lists of tasks, performance objectives, and enabling objectives for instruction in auto body technology. Following a curriculum framework that explains major content, laboratory activities, and intended outcomes, the document lists all tasks covered in the curriculum. The bulk of the document consists of…

Development and Validation of Career Development Guidelines by Task/Activity Analysis of Occupational Safety and Health Professions: Industrial Hygiene and Safety Professional. Final Report. Technical Report XII.

ERIC Educational Resources Information Center

Vernon, Ralph J.; And Others

This report summarizes research findings which resulted in development of curricula for occupational safety and health professions based on task/activity analyses and related performance objectives. The first seven chapters focus on the seven objectives. Chapter 1, Literature Review and Selection of Employers, concerns tasks required for…

Task performance in astronomical adaptive optics

NASA Astrophysics Data System (ADS)

Barrett, Harrison H.; Myers, Kyle J.; Devaney, Nicholas; Dainty, J. C.; Caucci, Luca

2006-06-01

In objective or task-based assessment of image quality, figures of merit are defined by the performance of some specific observer on some task of scientific interest. This methodology is well established in medical imaging but is just beginning to be applied in astronomy. In this paper we survey the theory needed to understand the performance of ideal or ideal-linear (Hotelling) observers on detection tasks with adaptive-optical data. The theory is illustrated by discussing its application to detection of exoplanets from a sequence of short-exposure images.

Development of novel tasks for studying view-invariant object recognition in rodents: Sensitivity to scopolamine.

PubMed

Mitchnick, Krista A; Wideman, Cassidy E; Huff, Andrew E; Palmer, Daniel; McNaughton, Bruce L; Winters, Boyer D

2018-05-15

The capacity to recognize objects from different view-points or angles, referred to as view-invariance, is an essential process that humans engage in daily. Currently, the ability to investigate the neurobiological underpinnings of this phenomenon is limited, as few ethologically valid view-invariant object recognition tasks exist for rodents. Here, we report two complementary, novel view-invariant object recognition tasks in which rodents physically interact with three-dimensional objects. Prior to experimentation, rats and mice were given extensive experience with a set of 'pre-exposure' objects. In a variant of the spontaneous object recognition task, novelty preference for pre-exposed or new objects was assessed at various angles of rotation (45°, 90° or 180°); unlike control rodents, for whom the objects were novel, rats and mice tested with pre-exposed objects did not discriminate between rotated and un-rotated objects in the choice phase, indicating substantial view-invariant object recognition. Secondly, using automated operant touchscreen chambers, rats were tested on pre-exposed or novel objects in a pairwise discrimination task, where the rewarded stimulus (S+) was rotated (180°) once rats had reached acquisition criterion; rats tested with pre-exposed objects re-acquired the pairwise discrimination following S+ rotation more effectively than those tested with new objects. Systemic scopolamine impaired performance on both tasks, suggesting involvement of acetylcholine at muscarinic receptors in view-invariant object processing. These tasks present novel means of studying the behavioral and neural bases of view-invariant object recognition in rodents. Copyright © 2018 Elsevier B.V. All rights reserved.

Functional Task Test (FTT)

NASA Technical Reports Server (NTRS)

Bloomberg, Jacob J.; Mulavara, Ajitkumar; Peters, Brian T.; Rescheke, Millard F.; Wood, Scott; Lawrence, Emily; Koffman, Igor; Ploutz-Snyder, Lori; Spiering, Barry A.; Feeback, Daniel L.;

Amygdala lesions in rhesus monkeys fail to disrupt object choices based on internal context

PubMed Central

Rhodes, Sarah E. V.; Charles, David P.; Howland, Emily J.; Murray, Elisabeth A.

2012-01-01

We assessed the involvement of the amygdala in a task in which object choices were guided by internal context. Rhesus monkeys were trained on a biconditional discrimination whereby objects associated with food (but not water) were baited when the monkey was hungry, and objects associated with water (but not food) were baited when the monkey was thirsty. To solve this task monkeys were required to choose objects yielding the reward congruent with their internal motivational state. Lesions of the amygdala did not disrupt learning or performance of this task. We conclude that the involvement of the amygdala in selective-satiation tasks, which depends in part on a change in internal context, is not due to the amygdala playing a general role in representing, or using, internal context. PMID:22352788

Relationships between episodic memory performance prediction and sociodemographic variables among healthy older adults.

PubMed

de Oliveira, Glaucia Martins; Cachioni, Meire; Falcão, Deusivania; Batistoni, Samila; Lopes, Andrea; Guimarães, Vanessa; Lima-Silva, Thais Bento; Neri, Anita Liberalesso; Yassuda, Mônica Sanches

2015-01-01

Previous studies have suggested that performance prediction, an aspect of metamemory, may be associated with objective performance on memory tasks. The objective of the study was to describe memory prediction before performing an episodic memory task, in community-dwelling older adults, stratified by sex, age group and educational level. Additionally, the association between predicted and objective performance on a memory task was investigated. The study was based on data from 359 participants in the FIBRA study carried out at Ermelino Matarazzo, São Paulo. Memory prediction was assessed by posing the question: "If someone showed you a sheet with drawings of 10 pictures to observe for 30 seconds, how many pictures do you think you could remember without seeing the sheet?". Memory performance was assessed by the memorization of 10 black and white pictures from the Brief Cognitive Screening Battery (BCSB). No differences were found between men and women, nor for age group and educational level, in memory performance prediction before carrying out the memory task. There was a modest association (rho=0.11, p=0.041) between memory prediction and performance in immediate memory. On multivariate linear regression analyses, memory performance prediction was moderately significantly associated with immediate memory (p=0.061). In this study, sociodemographic variables did not influence memory prediction, which was only modestly associated with immediate memory on the Brief Cognitive Screening Battery (BCSB).

Facility Maintenance. V-TECS Guide.

ERIC Educational Resources Information Center

Moore, Charles G.; And Others

This facility maintenance guide is a compilation of duties, tasks, performance objectives, and performance guides that deals with the psychomotor aspect of an occupation. The guide addresses the three domains of learning: psychomotor, cognitive, and affective. Each unit provides job-relevant tasks, standards of performance, source of standard,…

The effects of substitute multisensory feedback on task performance and the sense of presence in a virtual reality environment

PubMed Central

Milella, Ferdinando; Pinto, Carlo; Cant, Iain; White, Mark; Meyer, Georg

2018-01-01

Objective and subjective measures of performance in virtual reality environments increase as more sensory cues are delivered and as simulation fidelity increases. Some cues (colour or sound) are easier to present than others (object weight, vestibular cues) so that substitute cues can be used to enhance informational content in a simulation at the expense of simulation fidelity. This study evaluates how substituting cues in one modality by alternative cues in another modality affects subjective and objective performance measures in a highly immersive virtual reality environment. Participants performed a wheel change in a virtual reality (VR) environment. Auditory, haptic and visual cues, signalling critical events in the simulation, were manipulated in a factorial design. Subjective ratings were recorded via questionnaires. The time taken to complete the task was used as an objective performance measure. The results show that participants performed best and felt an increased sense of immersion and involvement, collectively referred to as ‘presence’, when substitute multimodal sensory feedback was provided. Significant main effects of audio and tactile cues on task performance and on participants' subjective ratings were found. A significant negative relationship was found between the objective (overall completion times) and subjective (ratings of presence) performance measures. We conclude that increasing informational content, even if it disrupts fidelity, enhances performance and user’s overall experience. On this basis we advocate the use of substitute cues in VR environments as an efficient method to enhance performance and user experience. PMID:29390023

The effects of substitute multisensory feedback on task performance and the sense of presence in a virtual reality environment.

PubMed

Cooper, Natalia; Milella, Ferdinando; Pinto, Carlo; Cant, Iain; White, Mark; Meyer, Georg

2018-01-01

Objective and subjective measures of performance in virtual reality environments increase as more sensory cues are delivered and as simulation fidelity increases. Some cues (colour or sound) are easier to present than others (object weight, vestibular cues) so that substitute cues can be used to enhance informational content in a simulation at the expense of simulation fidelity. This study evaluates how substituting cues in one modality by alternative cues in another modality affects subjective and objective performance measures in a highly immersive virtual reality environment. Participants performed a wheel change in a virtual reality (VR) environment. Auditory, haptic and visual cues, signalling critical events in the simulation, were manipulated in a factorial design. Subjective ratings were recorded via questionnaires. The time taken to complete the task was used as an objective performance measure. The results show that participants performed best and felt an increased sense of immersion and involvement, collectively referred to as 'presence', when substitute multimodal sensory feedback was provided. Significant main effects of audio and tactile cues on task performance and on participants' subjective ratings were found. A significant negative relationship was found between the objective (overall completion times) and subjective (ratings of presence) performance measures. We conclude that increasing informational content, even if it disrupts fidelity, enhances performance and user's overall experience. On this basis we advocate the use of substitute cues in VR environments as an efficient method to enhance performance and user experience.

Aspect-object alignment with Integer Linear Programming in opinion mining.

PubMed

Zhao, Yanyan; Qin, Bing; Liu, Ting; Yang, Wei

2015-01-01

Target extraction is an important task in opinion mining. In this task, a complete target consists of an aspect and its corresponding object. However, previous work has always simply regarded the aspect as the target itself and has ignored the important "object" element. Thus, these studies have addressed incomplete targets, which are of limited use for practical applications. This paper proposes a novel and important sentiment analysis task, termed aspect-object alignment, to solve the "object neglect" problem. The objective of this task is to obtain the correct corresponding object for each aspect. We design a two-step framework for this task. We first provide an aspect-object alignment classifier that incorporates three sets of features, namely, the basic, relational, and special target features. However, the objects that are assigned to aspects in a sentence often contradict each other and possess many complicated features that are difficult to incorporate into a classifier. To resolve these conflicts, we impose two types of constraints in the second step: intra-sentence constraints and inter-sentence constraints. These constraints are encoded as linear formulations, and Integer Linear Programming (ILP) is used as an inference procedure to obtain a final global decision that is consistent with the constraints. Experiments on a corpus in the camera domain demonstrate that the three feature sets used in the aspect-object alignment classifier are effective in improving its performance. Moreover, the classifier with ILP inference performs better than the classifier without it, thereby illustrating that the two types of constraints that we impose are beneficial.

ROBOSIGHT: Robotic Vision System For Inspection And Manipulation

NASA Astrophysics Data System (ADS)

Trivedi, Mohan M.; Chen, ChuXin; Marapane, Suresh

1989-02-01

Vision is an important sensory modality that can be used for deriving information critical to the proper, efficient, flexible, and safe operation of an intelligent robot. Vision systems are uti-lized for developing higher level interpretation of the nature of a robotic workspace using images acquired by cameras mounted on a robot. Such information can be useful for tasks such as object recognition, object location, object inspection, obstacle avoidance and navigation. In this paper we describe efforts directed towards developing a vision system useful for performing various robotic inspection and manipulation tasks. The system utilizes gray scale images and can be viewed as a model-based system. It includes general purpose image analysis modules as well as special purpose, task dependent object status recognition modules. Experiments are described to verify the robust performance of the integrated system using a robotic testbed.

Automotive Technology Curriculum Guide.

ERIC Educational Resources Information Center

Idaho State Dept. of Education, Boise. Div. of Vocational Education.

This Idaho state curriculum guide provides lists of tasks, performance objectives, and enabling objectives for instruction in automotive technology. The document begins with a list of all tasks covered by the curriculum, a short course outline, and a curriculum framework that explains major content, laboratory activities, and intended outcomes.…

Architectural Drafting: Commercial Applications. Teacher Guide.

ERIC Educational Resources Information Center

Whitney, Terry A.

This curriculum guide contains the technical information and tasks necessary for a student (who has already completed basic drafting) to be employed as an architectural drafter trainee. The curriculum is written in terms of student performance using measurable objectives, technical information, tasks developed to accomplish those objectives, and…

Motor learning from virtual reality to natural environments in individuals with Duchenne muscular dystrophy.

PubMed

Quadrado, Virgínia Helena; Silva, Talita Dias da; Favero, Francis Meire; Tonks, James; Massetti, Thais; Monteiro, Carlos Bandeira de Mello

2017-11-10

To examine whether performance improvements in the virtual environment generalize to the natural environment. we had 64 individuals, 32 of which were individuals with DMD and 32 were typically developing individuals. The groups practiced two coincidence timing tasks. In the more tangible button-press task, the individuals were required to 'intercept' a falling virtual object at the moment it reached the interception point by pressing a key on the computer. In the more abstract task, they were instructed to 'intercept' the virtual object by making a hand movement in a virtual environment using a webcam. For individuals with DMD, conducting a coincidence timing task in a virtual environment facilitated transfer to the real environment. However, we emphasize that a task practiced in a virtual environment should have higher rates of difficulties than a task practiced in a real environment. IMPLICATIONS FOR REHABILITATION Virtual environments can be used to promote improved performance in ?real-world? environments. Virtual environments offer the opportunity to create paradigms similar ?real-life? tasks, however task complexity and difficulty levels can be manipulated, graded and enhanced to increase likelihood of success in transfer of learning and performance. Individuals with DMD, in particular, showed immediate performance benefits after using virtual reality.

Word Recall: Cognitive Performance Within Internet Surveys

PubMed Central

Craig, Benjamin M; Jim, Heather S

2015-01-01

Background The use of online surveys for data collection has increased exponentially, yet it is often unclear whether interview-based cognitive assessments (such as face-to-face or telephonic word recall tasks) can be adapted for use in application-based research settings. Objective The objective of the current study was to compare and characterize the results of online word recall tasks to those of the Health and Retirement Study (HRS) and determine the feasibility and reliability of incorporating word recall tasks into application-based cognitive assessments. Methods The results of the online immediate and delayed word recall assessment, included within the Women’s Health and Valuation (WHV) study, were compared to the results of the immediate and delayed recall tasks of Waves 5-11 (2000-2012) of the HRS. Results Performance on the WHV immediate and delayed tasks demonstrated strong concordance with performance on the HRS tasks (ρc=.79, 95% CI 0.67-0.91), despite significant differences between study populations (P<.001) and study design. Sociodemographic characteristics and self-reported memory demonstrated similar relationships with performance on both the HRS and WHV tasks. Conclusions The key finding of this study is that the HRS word recall tasks performed similarly when used as an online cognitive assessment in the WHV. Online administration of cognitive tests, which has the potential to significantly reduce participant and administrative burden, should be considered in future research studies and health assessments. PMID:26543924

The Dynamic Multisensory Engram: Neural Circuitry Underlying Crossmodal Object Recognition in Rats Changes with the Nature of Object Experience.

PubMed

Jacklin, Derek L; Cloke, Jacob M; Potvin, Alphonse; Garrett, Inara; Winters, Boyer D

2016-01-27

Rats, humans, and monkeys demonstrate robust crossmodal object recognition (CMOR), identifying objects across sensory modalities. We have shown that rats' performance of a spontaneous tactile-to-visual CMOR task requires functional integration of perirhinal (PRh) and posterior parietal (PPC) cortices, which seemingly provide visual and tactile object feature processing, respectively. However, research with primates has suggested that PRh is sufficient for multisensory object representation. We tested this hypothesis in rats using a modification of the CMOR task in which multimodal preexposure to the to-be-remembered objects significantly facilitates performance. In the original CMOR task, with no preexposure, reversible lesions of PRh or PPC produced patterns of impairment consistent with modality-specific contributions. Conversely, in the CMOR task with preexposure, PPC lesions had no effect, whereas PRh involvement was robust, proving necessary for phases of the task that did not require PRh activity when rats did not have preexposure; this pattern was supported by results from c-fos imaging. We suggest that multimodal preexposure alters the circuitry responsible for object recognition, in this case obviating the need for PPC contributions and expanding PRh involvement, consistent with the polymodal nature of PRh connections and results from primates indicating a key role for PRh in multisensory object representation. These findings have significant implications for our understanding of multisensory information processing, suggesting that the nature of an individual's past experience with an object strongly determines the brain circuitry involved in representing that object's multisensory features in memory. The ability to integrate information from multiple sensory modalities is crucial to the survival of organisms living in complex environments. Appropriate responses to behaviorally relevant objects are informed by integration of multisensory object features. We used crossmodal object recognition tasks in rats to study the neurobiological basis of multisensory object representation. When rats had no prior exposure to the to-be-remembered objects, the spontaneous ability to recognize objects across sensory modalities relied on functional interaction between multiple cortical regions. However, prior multisensory exploration of the task-relevant objects remapped cortical contributions, negating the involvement of one region and significantly expanding the role of another. This finding emphasizes the dynamic nature of cortical representation of objects in relation to past experience. Copyright © 2016 the authors 0270-6474/16/361273-17$15.00/0.

Grasping objects by their handles: a necessary interaction between cognition and action

NASA Technical Reports Server (NTRS)

Creem, S. H.; Proffitt, D. R.; Kaiser, M. K. (Principal Investigator)

2001-01-01

Research has illustrated dissociations between "cognitive" and "action" systems, suggesting that different representations may underlie phenomenal experience and visuomotor behavior. However, these systems also interact. The present studies show a necessary interaction when semantic processing of an object is required for an appropriate action. Experiment 1 demonstrated that a semantic task interfered with grasping objects appropriately by their handles, but a visuospatial task did not. Experiment 2 assessed performance on a visuomotor task that had no semantic component and showed a reversal of the effects of the concurrent tasks. In Experiment 3, variations on concurrent word tasks suggested that retrieval of semantic information was necessary for appropriate grasping. In all, without semantic processing, the visuomotor system can direct the effective grasp of an object, but not in a manner that is appropriate for its use.

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

Gang, G; Siewerdsen, J; Stayman, J

Purpose: There has been increasing interest in integrating fluence field modulation (FFM) devices with diagnostic CT scanners for dose reduction purposes. Conventional FFM strategies, however, are often either based on heuristics or the analysis of filtered-backprojection (FBP) performance. This work investigates a prospective task-driven optimization of FFM for model-based iterative reconstruction (MBIR) in order to improve imaging performance at the same total dose as conventional strategies. Methods: The task-driven optimization framework utilizes an ultra-low dose 3D scout as a patient-specific anatomical model and a mathematical formation of the imaging task. The MBIR method investigated is quadratically penalized-likelihood reconstruction. The FFMmore » objective function uses detectability index, d’, computed as a function of the predicted spatial resolution and noise in the image. To optimize performance throughout the object, a maxi-min objective was adopted where the minimum d’ over multiple locations is maximized. To reduce the dimensionality of the problem, FFM is parameterized as a linear combination of 2D Gaussian basis functions over horizontal detector pixels and projection angles. The coefficients of these bases are found using the covariance matrix adaptation evolution strategy (CMA-ES) algorithm. The task-driven design was compared with three other strategies proposed for FBP reconstruction for a calcification cluster discrimination task in an abdomen phantom. Results: The task-driven optimization yielded FFM that was significantly different from those designed for FBP. Comparing all four strategies, the task-based design achieved the highest minimum d’ with an 8–48% improvement, consistent with the maxi-min objective. In addition, d’ was improved to a greater extent over a larger area within the entire phantom. Conclusion: Results from this investigation suggests the need to re-evaluate conventional FFM strategies for MBIR. The task-based optimization framework provides a promising approach that maximizes imaging performance under the same total dose constraint.« less

[Developmental changes of rapid automatized naming and Hiragana reading of Japanese in elementary-school children].

PubMed

Kobayashi, Tomoka; Inagaki, Masumi; Gunji, Atsuko; Yatabe, Kiyomi; Kita, Yosuke; Kaga, Makiko; Gotoh, Takaaki; Koike, Toshihide

2011-11-01

Two hundred and seven Japanese elementary school children aged from 6 (Grade 1) to 12 (Grade 6) years old were tested for their abilities to name numbers and pictured objects along with reading Hiragana characters and words. These children all showed typical development and their classroom teachers judged that they were not having any problems with reading or writing. The children were randomly divided into two groups, the first group was assigned to two naming tasks;the rapid automatized naming (RAN) of "numbers" and "pictured objects," the second group was assigned to two rapid alternative stimulus (RAS) naming tasks using numbers and pictured objects. All children were asked to perform two reading tasks that were written in Hiragana script: single mora reading task and four syllable word reading task. The total articulation time for naming and reading and performance in terms of accuracy were measured for each task. Developmental changes in these variables were evaluated. The articulation time was significantly longer for the first graders, and it gradually shortened as they moved through to the upper grades in all tasks. The articulation time reached a plateau in the 5th grade for the number naming, while gradual change continued after drastic change in the lower grades for the pictured object naming. The articulation times for the single mora reading and RAN of numbers correlated strongly. The articulation time for the RAS naming was significantly longer compared to that for the RAN, though there were very few errors. The RAS naming showed the highest correlation with the four syllable word reading. This study demonstrated that the performance in rapid automatized naming of numbers and pictures were closely related with performance on reading tasks. Thus Japanese children with reading disorders such as developmental dyslexia should also be evaluated for rapid automatized naming.

Fitts' Law in the Control of Isometric Grip Force With Naturalistic Targets.

PubMed

Thumser, Zachary C; Slifkin, Andrew B; Beckler, Dylan T; Marasco, Paul D

2018-01-01

Fitts' law models the relationship between amplitude, precision, and speed of rapid movements. It is widely used to quantify performance in pointing tasks, study human-computer interaction, and generally to understand perceptual-motor information processes, including research to model performance in isometric force production tasks. Applying Fitts' law to an isometric grip force task would allow for quantifying grasp performance in rehabilitative medicine and may aid research on prosthetic control and design. We examined whether Fitts' law would hold when participants attempted to accurately produce their intended force output while grasping a manipulandum when presented with images of various everyday objects (we termed this the implicit task). Although our main interest was the implicit task, to benchmark it and establish validity, we examined performance against a more standard visual feedback condition via a digital force-feedback meter on a video monitor (explicit task). Next, we progressed from visual force feedback with force meter targets to the same targets without visual force feedback (operating largely on feedforward control with tactile feedback). This provided an opportunity to see if Fitts' law would hold without vision, and allowed us to progress toward the more naturalistic implicit task (which does not include visual feedback). Finally, we changed the nature of the targets from requiring explicit force values presented as arrows on a force-feedback meter (explicit targets) to the more naturalistic and intuitive target forces implied by images of objects (implicit targets). With visual force feedback the relation between task difficulty and the time to produce the target grip force was predicted by Fitts' law (average r 2 = 0.82). Without vision, average grip force scaled accurately although force variability was insensitive to the target presented. In contrast, images of everyday objects generated more reliable grip forces without the visualized force meter. In sum, population means were well-described by Fitts' law for explicit targets with vision ( r 2 = 0.96) and implicit targets ( r 2 = 0.89), but not as well-described for explicit targets without vision ( r 2 = 0.54). Implicit targets should provide a realistic see-object-squeeze-object test using Fitts' law to quantify the relative speed-accuracy relationship of any given grasper.

Cognitive control components and speech symptoms in people with schizophrenia.

PubMed

Becker, Theresa M; Cicero, David C; Cowan, Nelson; Kerns, John G

2012-03-30

Previous schizophrenia research suggests poor cognitive control is associated with schizophrenia speech symptoms. However, cognitive control is a broad construct. Two important cognitive control components are poor goal maintenance and poor verbal working memory storage. In the current research, people with schizophrenia (n=45) performed three cognitive tasks that varied in their goal maintenance and verbal working memory storage demands. Speech symptoms were assessed using clinical rating scales, ratings of disorganized speech from typed transcripts, and self-reported disorganization. Overall, alogia was associated with both goal maintenance and verbal working memory tasks. Objectively rated disorganized speech was associated with poor goal maintenance and with a task that included both goal maintenance and verbal working memory storage demands. In contrast, self-reported disorganization was unrelated to either amount of objectively rated disorganized speech or to cognitive control task performance, instead being associated with negative mood symptoms. Overall, our results suggest that alogia is associated with both poor goal maintenance and poor verbal working memory storage and that disorganized speech is associated with poor goal maintenance. In addition, patients' own assessment of their disorganization is related to negative mood, but perhaps not to objective disorganized speech or to cognitive control task performance. Published by Elsevier Ireland Ltd.

Quantifying usability: an evaluation of a diabetes mHealth system on effectiveness, efficiency, and satisfaction metrics with associated user characteristics

PubMed Central

Staggers, Nancy

2016-01-01

Objective Mobile health (mHealth) systems are becoming more common for chronic disease management, but usability studies are still needed on patients’ perspectives and mHealth interaction performance. This deficiency is addressed by our quantitative usability study of a mHealth diabetes system evaluating patients’ task performance, satisfaction, and the relationship of these measures to user characteristics. Materials and Methods We used metrics in the International Organization for Standardization (ISO) 9241-11 standard. After standardized training, 10 patients performed representative tasks and were assessed on individual task success, errors, efficiency (time on task), satisfaction (System Usability Scale [SUS]) and user characteristics. Results Tasks of exporting and correcting values proved the most difficult, had the most errors, the lowest task success rates, and consumed the longest times on task. The average SUS satisfaction score was 80.5, indicating good but not excellent system usability. Data trends showed males were more successful in task completion, and younger participants had higher performance scores. Educational level did not influence performance, but a more recent diabetes diagnosis did. Patients with more experience in information technology (IT) also had higher performance rates. Discussion Difficult task performance indicated areas for redesign. Our methods can assist others in identifying areas in need of improvement. Data about user background and IT skills also showed how user characteristics influence performance and can provide future considerations for targeted mHealth designs. Conclusion Using the ISO 9241-11 usability standard, the SUS instrument for satisfaction and measuring user characteristics provided objective measures of patients’ experienced usability. These could serve as an exemplar for standardized, quantitative methods for usability studies on mHealth systems. PMID:26377990

Culture & Cognition Laboratory

DTIC Science & Technology

2011-05-01

life: Real world social-interaction cooperative tasks are inherently unequal in difficulty. Re-scoring performance on unequal tasks in order to enable...real- world situations to which this model is intended to apply, it is possible for calls for help to not be heard, or for a potential help-provider to...not have clear, well-defined objectives. Since many complex real- worlds tasks are not well-defined, defining a realistic objective can be considered a

Principles of Technology, Units 1-7. Curriculum Guide.

ERIC Educational Resources Information Center

Campbell, Robert, Comp.

This Idaho secondary education curriculum guide provides lists of tasks, performance objectives, and enabling objectives for instruction intended to impart entry-level employment skills in industrial technology. The first list is a general job competencies task profile, followed by a sheet on which teachers can evaluate students' general job…

Item Dependency in an Objective Structured Clinical Examination

ERIC Educational Resources Information Center

Iramaneerat, Cherdsak; Myford, Carol M.; Yudkowsky, Rachel

2006-01-01

An Objective Structured Clinical Examination (OSCE) is an assessment approach employed in medical education, in which residents rotate through multiple stations of standardized clinical tasks to evaluate their clinical competence. Because items used to evaluate residents' performance in each OSCE station are linked to the same task and are rated…

Multiple task performance as a predictor of the potential of air traffic controller trainees.

DOT National Transportation Integrated Search

1972-01-01

Two hundred and twenty-nine air traffic controller trainees were tested on the CAMI Multiple Task Performance Battery. The battery provides objective measures of monitoring, arithmetical skills, visual discrimination, and group problem solving. The c...

Business Law: Task Analyses. Competency-Based Education.

ERIC Educational Resources Information Center

Henrico County Public Schools, Glen Allen, VA. Virginia Vocational Curriculum Center.

This task analysis guide is intended to help teachers and administrators develop instructional materials and implement competency-based education for a course in business law. Section 1 contains a validated task inventory for business law. For each task, applicable information pertaining to performance and enabling objectives, criterion-referenced…

Relative recency influences object-in-context memory

PubMed Central

Tam, Shu K.E.; Bonardi, Charlotte; Robinson, Jasper

2015-01-01

In two experiments rats received training on an object-in-context (OIC) task, in which they received preexposure to object A in context x, followed by exposure to object B in context y. In a subsequent test both A and B are presented in either context x or context y. Usually more exploration is seen of the object that has not previously been paired with the test context, an effect attributed to the ability to remember where an object was encountered. However, in the typical version of this task, object A has also been encountered less recently than object B at test. This is precisely the arrangement in tests of ‘relatively recency’ (RR), in which more remotely presented objects are explored more than objects experienced more recently. RR could contaminate performance on the OIC task, by enhancing the OIC effect when animals are tested in context y, and masking it when the test is in context x. This possibility was examined in two experiments, and evidence for superior performance in context y was obtained. The implications of this for theoretical interpretations of recognition memory and the procedures used to explore it are discussed. PMID:25546721

Development of a task-level robot programming and simulation system

NASA Technical Reports Server (NTRS)

Liu, H.; Kawamura, K.; Narayanan, S.; Zhang, G.; Franke, H.; Ozkan, M.; Arima, H.; Liu, H.

1987-01-01

An ongoing project in developing a Task-Level Robot Programming and Simulation System (TARPS) is discussed. The objective of this approach is to design a generic TARPS that can be used in a variety of applications. Many robotic applications require off-line programming, and a TARPS is very useful in such applications. Task level programming is object centered in that the user specifies tasks to be performed instead of robot paths. Graphics simulation provides greater flexibility and also avoids costly machine setup and possible damage. A TARPS has three major modules: world model, task planner and task simulator. The system architecture, design issues and some preliminary results are given.

Node, Node-Link, and Node-Link-Group Diagrams: An Evaluation.

PubMed

Saket, Bahador; Simonetto, Paolo; Kobourov, Stephen; Börner, Katy

2014-12-01

Effectively showing the relationships between objects in a dataset is one of the main tasks in information visualization. Typically there is a well-defined notion of distance between pairs of objects, and traditional approaches such as principal component analysis or multi-dimensional scaling are used to place the objects as points in 2D space, so that similar objects are close to each other. In another typical setting, the dataset is visualized as a network graph, where related nodes are connected by links. More recently, datasets are also visualized as maps, where in addition to nodes and links, there is an explicit representation of groups and clusters. We consider these three Techniques, characterized by a progressive increase of the amount of encoded information: node diagrams, node-link diagrams and node-link-group diagrams. We assess these three types of diagrams with a controlled experiment that covers nine different tasks falling broadly in three categories: node-based tasks, network-based tasks and group-based tasks. Our findings indicate that adding links, or links and group representations, does not negatively impact performance (time and accuracy) of node-based tasks. Similarly, adding group representations does not negatively impact the performance of network-based tasks. Node-link-group diagrams outperform the others on group-based tasks. These conclusions contradict results in other studies, in similar but subtly different settings. Taken together, however, such results can have significant implications for the design of standard and domain snecific visualizations tools.

Task-dependency and structure-dependency in number interference effects in sentence comprehension

PubMed Central

Franck, Julie; Colonna, Saveria; Rizzi, Luigi

2015-01-01

We report three experiments on French that explore number mismatch effects in intervention configurations in the comprehension of object A’-dependencies, relative clauses and questions. The study capitalizes on the finding of object attraction in sentence production, in which speakers sometimes erroneously produce a verb that agrees in number with a plural object in object relative clauses. Evidence points to the role of three critical constructs from formal syntax: intervention, intermediate traces and c-command (Franck et al., 2010). Experiment 1, using a self-paced reading procedure on these grammatical structures with an agreement error on the verb, shows an enhancing effect of number mismatch in intervention configurations, with faster reading times with plural (mismatching) objects. Experiment 2, using an on-line grammaticality judgment task on the ungrammatical versions of these structures, shows an interference effect in the form of attraction, with slower response times with plural objects. Experiment 3 with a similar grammaticality judgment task shows stronger attraction from c-commanding than from preceding interveners. Overall, the data suggest that syntactic computations in performance refer to the same syntactic representations in production and comprehension, but that different tasks tap into different processes involved in parsing: whereas performance in self-paced reading reflects the intervention of the subject in the process of building an object A’-dependency, performance in grammaticality judgment reflects intervention of the object on the computation of the subject-verb agreement dependency. The latter shows the hallmarks of structure-dependent attraction effects in sentence production, in particular, a sensitivity to specific characteristics of hierarchical representations. PMID:25914652

Catalog of Performance Objectives and Performance Guides for Physical Therapy Occupations.

ERIC Educational Resources Information Center

Reneau, Fred; Hahn, Dave

This catalog provides a worker-based description of duties, tasks, performance objectives and guides, and related data for physical therapy occupations. Duties covered include the following: (1) performing administrative/clerical functions; (2) communicating information; (3) providing patient care services; (4) performing support service; (5)…

Laser System Technician. A Catalog of Performance Objectives and Performance Guides.

ERIC Educational Resources Information Center

Florida State Dept. of Education, Tallahassee. Div. of Vocational, Adult, and Community Education.

This Vocational-Technical Education Consortium of States (V-TECS) catalog contains the state-of-the-art tasks and standards of performance for the occupation of laser system technician. It provides the curriculum specialist or instructor with the foundation for instructional development. Performance objectives and performance guides are provided…

Effects of paired-object affordance in search tasks across the adult lifespan.

PubMed

Wulff, Melanie; Stainton, Alexandra; Rotshtein, Pia

2016-06-01

The study investigated the processes underlying the retrieval of action information about functional object pairs, focusing on the contribution of procedural and semantic knowledge. We further assessed whether the retrieval of action knowledge is affected by task demands and age. The contribution of procedural knowledge was examined by the way objects were selected, specifically whether active objects were selected before passive objects. The contribution of semantic knowledge was examined by manipulating the relation between targets and distracters. A touchscreen-based search task was used testing young, middle-aged, and elderly participants. Participants had to select by touching two targets among distracters using two search tasks. In an explicit action search task, participants had to select two objects which afforded a mutual action (e.g., functional pair: hammer-nail). Implicit affordance perception was tested using a visual color-matching search task; participants had to select two objects with the same colored frame. In both tasks, half of the colored targets also afforded an action. Overall, middle-aged participants performed better than young and elderly participants, specifically in the action task. Across participants in the action task, accuracy was increased when the distracters were semantically unrelated to the functional pair, while the opposite pattern was observed in the color task. This effect was enhanced with increased age. In the action task all participants utilized procedural knowledge, i.e., selected the active object before the passive object. This result supports the dual-route account from vision to action. Semantic knowledge contributed to both the action and the color task, but procedural knowledge associated with the direct route was primarily retrieved when the task was action-relevant. Across the adulthood lifespan, the data show inverted U-shaped effects of age on the retrieval of action knowledge. Age also linearly increased the involvement of the indirect (semantic) route and the integration of information of the direct and the indirect routes in selection processes. Copyright © 2016 Elsevier Inc. All rights reserved.

Amygdala lesions in rhesus monkeys fail to disrupt object choices based on internal context.

PubMed

Rhodes, Sarah E V; Charles, David P; Howland, Emily J; Murray, Elisabeth A

2012-04-01

We assessed the involvement of the amygdala in a task in which object choices were guided by internal context. Rhesus monkeys were trained on a biconditional discrimination whereby objects associated with food (but not water) were baited when the monkey was hungry, and objects associated with water (but not food) were baited when the monkey was thirsty. To solve this task, monkeys were required to choose objects yielding the reward congruent with their internal motivational state. Lesions of the amygdala did not disrupt learning or performance of this task. We conclude that the involvement of the amygdala in selective-satiation tasks, which depends in part on a change in internal context, is not due to the amygdala playing a general role in representing, or using, internal context. (c) 2012 APA, all rights reserved

Functional but Inefficient Kinesthetic Motor Imagery in Adolescents with Autism Spectrum Disorder.

PubMed

Chen, Ya-Ting; Tsou, Kuo-Su; Chen, Hao-Ling; Wong, Ching-Ching; Fan, Yang-Teng; Wu, Chien-Te

2018-03-01

Whether action representation in individuals with autism spectrum disorder (ASD) is deficient remains controversial, as previous studies of action observation or imitation report conflicting results. Here we investigated the characteristics of action representation in adolescents with ASD through motor imagery (MI) using a hand rotation and an object rotation task. Comparable with the typically-developing group, the individuals with ASD were able to spontaneously use kinesthetic MI to perform the hand rotation task, as manifested by the significant biomechanical effects. However, the ASD group performed significantly slower only in the hand rotation task, but not in the object rotation task. The findings suggest that the adolescents with ASD showed inefficient but functional kinesthetic MI, implicating that their action representation might be preserved.

Individual personality differences in goats predict their performance in visual learning and non-associative cognitive tasks.

PubMed

Nawroth, Christian; Prentice, Pamela M; McElligott, Alan G

2017-01-01

Variation in common personality traits, such as boldness or exploration, is often associated with risk-reward trade-offs and behavioural flexibility. To date, only a few studies have examined the effects of consistent behavioural traits on both learning and cognition. We investigated whether certain personality traits ('exploration' and 'sociability') of individuals were related to cognitive performance, learning flexibility and learning style in a social ungulate species, the goat (Capra hircus). We also investigated whether a preference for feature cues rather than impaired learning abilities can explain performance variation in a visual discrimination task. We found that personality scores were consistent across time and context. Less explorative goats performed better in a non-associative cognitive task, in which subjects had to follow the trajectory of a hidden object (i.e. testing their ability for object permanence). We also found that less sociable subjects performed better compared to more sociable goats in a visual discrimination task. Good visual learning performance was associated with a preference for feature cues, indicating personality-dependent learning strategies in goats. Our results suggest that personality traits predict the outcome in visual discrimination and non-associative cognitive tasks in goats and that impaired performance in a visual discrimination tasks does not necessarily imply impaired learning capacities, but rather can be explained by a varying preference for feature cues. Copyright © 2016 Elsevier B.V. All rights reserved.

Evidence-Based Occupational Hearing Screening I: Modeling the Effects of Real-World Noise Environments on the Likelihood of Effective Speech Communication.

PubMed

Soli, Sigfrid D; Giguère, Christian; Laroche, Chantal; Vaillancourt, Véronique; Dreschler, Wouter A; Rhebergen, Koenraad S; Harkins, Kevin; Ruckstuhl, Mark; Ramulu, Pradeep; Meyers, Lawrence S

The objectives of this study were to (1) identify essential hearing-critical job tasks for public safety and law enforcement personnel; (2) determine the locations and real-world noise environments where these tasks are performed; (3) characterize each noise environment in terms of its impact on the likelihood of effective speech communication, considering the effects of different levels of vocal effort, communication distances, and repetition; and (4) use this characterization to define an objective normative reference for evaluating the ability of individuals to perform essential hearing-critical job tasks in noisy real-world environments. Data from five occupational hearing studies performed over a 17-year period for various public safety agencies were analyzed. In each study, job task analyses by job content experts identified essential hearing-critical tasks and the real-world noise environments where these tasks are performed. These environments were visited, and calibrated recordings of each noise environment were made. The extended speech intelligibility index (ESII) was calculated for each 4-sec interval in each recording. These data, together with the estimated ESII value required for effective speech communication by individuals with normal hearing, allowed the likelihood of effective speech communication in each noise environment for different levels of vocal effort and communication distances to be determined. These likelihoods provide an objective norm-referenced and standardized means of characterizing the predicted impact of real-world noise on the ability to perform essential hearing-critical tasks. A total of 16 noise environments for law enforcement personnel and eight noise environments for corrections personnel were analyzed. Effective speech communication was essential to hearing-critical tasks performed in these environments. Average noise levels, ranged from approximately 70 to 87 dBA in law enforcement environments and 64 to 80 dBA in corrections environments. The likelihood of effective speech communication at communication distances of 0.5 and 1 m was often less than 0.50 for normal vocal effort. Likelihood values often increased to 0.80 or more when raised or loud vocal effort was used. Effective speech communication at and beyond 5 m was often unlikely, regardless of vocal effort. ESII modeling of nonstationary real-world noise environments may prove an objective means of characterizing their impact on the likelihood of effective speech communication. The normative reference provided by these measures predicts the extent to which hearing impairments that increase the ESII value required for effective speech communication also decrease the likelihood of effective speech communication. These predictions may provide an objective evidence-based link between the essential hearing-critical job task requirements of public safety and law enforcement personnel and ESII-based hearing assessment of individuals who seek to perform these jobs.

Electroencephalographic Monitoring of Cognitive Fatigue

NASA Technical Reports Server (NTRS)

Montgomery, Leslie D.; Montgomery, Richard W.; Ku, Yu-Tsuan E.; Luna, Bernadette

2000-01-01

Mental exhaustion often poses a serious risk, even when performance is not apparently degraded. When such fatigue is associated with sustained performance of a single type of cognitive task it may be related to the metabolic energy required for sustained activation of cortical fields specialized for that task. The objective of this study was to adapt EEG to monitor cortical energy dissipation at a functionally specialized site over a long period of repetitive performance of a cognitive task.

Horticulture III, IV, and V. Task Analyses. Competency-Based Education.

ERIC Educational Resources Information Center

Henrico County Public Schools, Glen Allen, VA. Virginia Vocational Curriculum Center.

This task analysis guide is intended to help teachers and administrators develop instructional materials and implement competency-based education in the horticulture program. Section 1 contains a validated task inventory for horticulture III, IV, and V. For each task, applicable information pertaining to performance and enabling objectives,…

Grip type and task goal modify reach-to-grasp performance in post-stroke hemiparesis.

PubMed

Schaefer, Sydney Y; DeJong, Stacey L; Cherry, Kendra M; Lang, Catherine E

2012-04-01

This study investigated whether grip type and/or task goal influenced reaching and grasping performance in poststroke hemiparesis. Sixteen adults with poststroke hemiparesis and twelve healthy adults reached to and grasped a cylindrical object using one of two grip types (3-finger or palmar) to achieve one of two task goals (hold or lift). Performance of the stroke group was characteristic of hemiparetic limb movement during reach-to-grasp, with more curved handpaths and slower velocities compared with the control group. These effects were present regardless of grip type or task goal. Other measures of reaching (reach time and reach velocity at object contact) and grasping (peak thumb-index finger aperture during the reach and peak grip force during the grasp) were differentially affected by grip type, task goal, or both, despite the presence of hemiparesis, providing new evidence that changes in motor patterns after stroke may occur to compensate for stroke-related motor impairment.

Grip type and task goal modify reach-to-grasp performance in post-stroke hemiparesis

PubMed Central

Schaefer, Sydney Y.; DeJong, Stacey L.; Cherry, Kendra M.; Lang, Catherine E.

2011-01-01

This study investigated whether grip type and/or task goal influenced reaching and grasping performance in post-stroke hemiparesis. Sixteen adults with post-stroke hemiparesis and twelve healthy adults reached to and grasped a cylindrical object using one of two grip types (3-finger or palmar) to achieve one of two task goals (hold or lift). Performance of the stroke group was characteristic of hemiparetic limb movement during reach-to-grasp, with more curved handpaths and slower velocities compared to the control group. These effects were present regardless of grip type or task goal. Other measures of reaching (reach time and reach velocity at object contact) and grasping (peak thumb-index finger aperture during the reach and peak grip force during the grasp) were differentially affected by grip type, task goal, or both, despite the presence of hemiparesis, providing new evidence that changes in motor patterns after stroke may occur to compensate for stroke-related motor impairment. PMID:22357103

Young children’s ability to use 2-dimensional and 3-dimensional symbols to show placements of body touches and hidden objects

PubMed Central

Lytle, Nicole; London, Kamala; Bruck, Maggie

2015-01-01

In two experiments, we investigated 3- to 5-year-old children’s ability to use dolls and human figure drawings as symbols to map body touches. In Experiment 1 stickers were placed on different locations of children’s bodies, and they were asked to indicate the location of the sticker using three different symbols: a doll, a human figure drawing, and the adult researcher. Performance on the tasks increased with age, but many 5-year-olds did not attain perfect performance. Surprisingly, younger children made more errors on the 2D human figure drawing task compared to the 3D doll and adult tasks. In Experiment 2, we compared children’s ability to use 3D and 2D symbols to indicate body touch as well as to guide their search for a hidden object. We replicated the findings of Experiment 1 for the body touch task: for younger children, 3D symbols were easier to use than 2D symbols. However, the reverse pattern was found for the object locations task with children showing superior performance using 2D drawings over 3D models. Though children showed developmental improvements in using dolls and drawings to show where they were touched, less than two-thirds of the 5-year-olds performed perfectly on the touch tasks. Developmental as well as forensic implications of these results are discussed. PMID:25781003

Cognitive and Physical Fatigue Tasks Enhance Pain, Cognitive Fatigue and Physical Fatigue in People with Fibromyalgia

PubMed Central

Dailey, Dana L; Keffala, Valerie J; Sluka, Kathleen A

2014-01-01

Objective Fibromyalgia is a condition characterized by chronic widespread muscle pain and fatigue. The primary objective of this study was to determine if pain, perceived cognitive fatigue, and perceived physical fatigue were enhanced in participants with fibromyalgia compared to healthy controls during a cognitive fatigue task, a physical fatigue task and a dual fatigue task. Methods Twenty four people with fibromyalgia and 33 healthy controls completed pain, fatigue and function measures. A cognitive fatigue task (Controlled Oral Word Association Test) and physical fatigue task (Valpar peg test) were done individually and combined for a dual fatigue task. Resting pain, perceived cognitive fatigue and perceived physical fatigue were assessed during each task using visual analogue scales. Function was assessed with shoulder range of motion and grip. Results People with fibromyalgia had significantly higher increases in pain, cognitive fatigue and physical fatigue when compared to healthy controls after completion of a cognitive fatigue task, a physical fatigue task, or a dual fatigue task (p<0.01). People with fibromyalgia performed equivalently on measures of physical performance and cognitive performance on the physical and cognitive fatigue tasks, respectively. Conclusions These data show that people with fibromyalgia show larger increases in pain, perceived cognitive fatigue and perceived physical fatigue to both cognitive and physical fatigue tasks compared to healthy controls. The increases in pain and fatigue during cognitive and physical fatigue tasks could influence subject participation in daily activities and rehabilitation. PMID:25074583

Information based universal feature extraction

NASA Astrophysics Data System (ADS)

Amiri, Mohammad; Brause, Rüdiger

2015-02-01

In many real world image based pattern recognition tasks, the extraction and usage of task-relevant features are the most crucial part of the diagnosis. In the standard approach, they mostly remain task-specific, although humans who perform such a task always use the same image features, trained in early childhood. It seems that universal feature sets exist, but they are not yet systematically found. In our contribution, we tried to find those universal image feature sets that are valuable for most image related tasks. In our approach, we trained a neural network by natural and non-natural images of objects and background, using a Shannon information-based algorithm and learning constraints. The goal was to extract those features that give the most valuable information for classification of visual objects hand-written digits. This will give a good start and performance increase for all other image learning tasks, implementing a transfer learning approach. As result, in our case we found that we could indeed extract features which are valid in all three kinds of tasks.

Cross-cultural differences in cognitive development: attention to relations and objects.

PubMed

Kuwabara, Megumi; Smith, Linda B

2012-09-01

Growing evidence indicates a suite of generalized differences in the attentional and cognitive processing of adults from Eastern and Western cultures. Cognition in Eastern adults is often more relational and in Western adults is more object focused. Three experiments examined whether these differences characterize the cognition of preschool children in the two cultures. In Experiment 1, 4-year-olds from the two cultures (N=64) participated in a relational match-to-standard task in two conditions, with simple or richly detailed objects, in which a focus on individual objects may hurt performance. Rich objects, consistent with past research, strongly limited the performance of U.S. children but not Japanese children. In Experiment 2, U.S. and Japanese 4-year-olds (N=72) participated in a visual search task that required them to find a specific object in a cluttered, but organized as a scene, visual field in which object-centric attention might be expected to aid performance and relational attentional pattern may hinder the performance because of relational structure that was poised by the scene. U.S. children outperformed Japanese children. In Experiment 3, 4-year-olds from both cultures (N=36) participated in a visual search task that was similar to Experiment 2 but with randomly placed objects, where there should not be a difference between the performance of two cultures because the relational structure that may be posed by the scene is eliminated. This double-dissociation is discussed in terms of implications for different developmental trajectories, with different developmental subtasks in the two cultures. Copyright © 2012 Elsevier Inc. All rights reserved.

Cross-cultural differences in cognitive development: Attention to relations and objects

PubMed Central

Kuwabara, Megumi; Smith, Linda B.

2013-01-01

Growing evidence indicates a suite of generalized differences in the attentional and cognitive processing of adults from Eastern and Western cultures. Cognition in Eastern adults is often more relational and in Western adults is more object focused. Three experiments examined whether these differences characterize the cognition of preschool children in the two cultures. In Experiment 1, 4-year-olds from the two cultures (N = 64) participated in a relational match-to-standard task in two conditions, with simple or richly detailed objects, in which a focus on individual objects may hurt performance. Rich objects, consistent with past research, strongly limited the performance of U.S. children but not Japanese children. In Experiment 2, U.S. and Japanese 4-year-olds (N = 72) participated in a visual search task that required them to find a specific object in a cluttered, but organized as a scene, visual field in which object-centric attention might be expected to aid performance and relational attentional pattern may hinder the performance because of relational structure that was poised by the scene. U.S. children outperformed Japanese children. In Experiment 3, 4-year-olds from both cultures (N = 36) participated in a visual search task that was similar to Experiment 2 but with randomly placed objects, where there should not be a difference between the performance of two cultures because the relational structure that may be posed by the scene is eliminated. This double-dissociation is discussed in terms of implications for different developmental trajectories, with different developmental subtasks in the two cultures. PMID:22677459

Maternal docosahexaenoic acid intake levels during pregnancy and infant performance on a novel object search task at 22 months.

PubMed

Rees, Alison; Sirois, Sylvain; Wearden, Alison

2014-01-01

This study investigated maternal prenatal docosahexaenoic acid (DHA) intake and infant cognitive development at 22 months. Estimates for second- and third-trimester maternal DHA intake levels were obtained using a comprehensive Food Frequency Questionnaire. Infants (n = 67) were assessed at 22 months on a novel object search task. Mothers' DHA intake levels were divided into high or low groups, with analyses revealing a significant positive effect of third-trimester DHA on object search task performance. The third trimester appears to be a critical time for ensuring adequate maternal DHA levels to facilitate optimum cognitive development in late infancy. © 2014 The Authors. Child Development published by Wiley Periodicals, Inc. on behalf of Society for Research in Child Development.

Object permanence in the Goffin cockatoo (Cacatua goffini).

PubMed

Auersperg, Alice M I; Szabo, Birgit; von Bayern, Auguste M P; Bugnyar, Thomas

2014-02-01

The ability to represent hidden objects plays an important role in the survival of many species. In order to provide an inclusive synopsis of the current benchmark tasks used to test object permanence in animals for a psittacine representative, we tested eight Goffin cockatoos (Cacatua goffini) on Stages 3-6 of Piagetian object permanence as well as derivations of spatial transposition, rotation, and translocation tasks. Subjects instantly solved visible displacement 3b and 4a but showed an extended plateau for solving Stage 5a at a very late age (10 months). Subjects readily solved most invisible displacement tasks including double hidings and four angles (90°, 180°, 270°, and 360°) of rotation and translocations at high performance levels, although Piagetian Stage 6 invisible displacement tasks caused more difficulties for the animals than transposition, rotations, and translocation tasks. PsycINFO Database Record (c) 2014 APA, all rights reserved.

Enhancing cognition with video games: a multiple game training study.

PubMed

Oei, Adam C; Patterson, Michael D

2013-01-01

Previous evidence points to a causal link between playing action video games and enhanced cognition and perception. However, benefits of playing other video games are under-investigated. We examined whether playing non-action games also improves cognition. Hence, we compared transfer effects of an action and other non-action types that required different cognitive demands. We instructed 5 groups of non-gamer participants to play one game each on a mobile device (iPhone/iPod Touch) for one hour a day/five days a week over four weeks (20 hours). Games included action, spatial memory, match-3, hidden- object, and an agent-based life simulation. Participants performed four behavioral tasks before and after video game training to assess for transfer effects. Tasks included an attentional blink task, a spatial memory and visual search dual task, a visual filter memory task to assess for multiple object tracking and cognitive control, as well as a complex verbal span task. Action game playing eliminated attentional blink and improved cognitive control and multiple-object tracking. Match-3, spatial memory and hidden object games improved visual search performance while the latter two also improved spatial working memory. Complex verbal span improved after match-3 and action game training. Cognitive improvements were not limited to action game training alone and different games enhanced different aspects of cognition. We conclude that training specific cognitive abilities frequently in a video game improves performance in tasks that share common underlying demands. Overall, these results suggest that many video game-related cognitive improvements may not be due to training of general broad cognitive systems such as executive attentional control, but instead due to frequent utilization of specific cognitive processes during game play. Thus, many video game training related improvements to cognition may be attributed to near-transfer effects.

Nicotinic Receptor Gene CHRNA4 Interacts with Processing Load in Attention

PubMed Central

Espeseth, Thomas; Sneve, Markus Handal; Rootwelt, Helge; Laeng, Bruno

2010-01-01

Background Pharmacological studies suggest that cholinergic neurotransmission mediates increases in attentional effort in response to high processing load during attention demanding tasks [1]. Methodology/Principal Findings In the present study we tested whether individual variation in CHRNA4, a gene coding for a subcomponent in α4β2 nicotinic receptors in the human brain, interacted with processing load in multiple-object tracking (MOT) and visual search (VS). We hypothesized that the impact of genotype would increase with greater processing load in the MOT task. Similarly, we predicted that genotype would influence performance under high but not low load in the VS task. Two hundred and two healthy persons (age range = 39–77, Mean = 57.5, SD = 9.4) performed the MOT task in which twelve identical circular objects moved about the display in an independent and unpredictable manner. Two to six objects were designated as targets and the remaining objects were distracters. The same observers also performed a visual search for a target letter (i.e. X or Z) presented together with five non-targets while ignoring centrally presented distracters (i.e. X, Z, or L). Targets differed from non-targets by a unique feature in the low load condition, whereas they shared features in the high load condition. CHRNA4 genotype interacted with processing load in both tasks. Homozygotes for the T allele (N = 62) had better tracking capacity in the MOT task and identified targets faster in the high load trials of the VS task. Conclusion The results support the hypothesis that the cholinergic system modulates attentional effort, and that common genetic variation can be used to study the molecular biology of cognition. PMID:21203548

Human interaction with robotic systems: performance and workload evaluations.

PubMed

Reinerman-Jones, L; Barber, D J; Szalma, J L; Hancock, P A

2017-10-01

We first tested the effect of differing tactile informational forms (i.e. directional cues vs. static cues vs. dynamic cues) on objective performance and perceived workload in a collaborative human-robot task. A second experiment evaluated the influence of task load and informational message type (i.e. single words vs. grouped phrases) on that same collaborative task. In both experiments, the relationship of personal characteristics (attentional control and spatial ability) to performance and workload was also measured. In addition to objective performance and self-report of cognitive load, we evaluated different physiological responses in each experiment. Results showed a performance-workload association for directional cues, message type and task load. EEG measures however, proved generally insensitive to such task load manipulations. Where significant EEG effects were observed, right hemisphere amplitude differences predominated, although unexpectedly these latter relationships were negative. Although EEG measures were partially associated with performance, they appear to possess limited utility as measures of workload in association with tactile displays. Practitioner Summary: As practitioners look to take advantage of innovative tactile displays in complex operational realms like human-robotic interaction, associated performance effects are mediated by cognitive workload. Despite some patterns of association, reliable reflections of operator state can be difficult to discern and employ as the number, complexity and sophistication of these respective measures themselves increase.

The Effects of Visual Discriminability and Rotation Angle on 30-Month-Olds’ Search Performance in Spatial Rotation Tasks

PubMed Central

Ebersbach, Mirjam; Nawroth, Christian

2016-01-01

Tracking objects that are hidden and then moved is a crucial ability related to object permanence, which develops across several stages in early childhood. In spatial rotation tasks, children observe a target object that is hidden in one of two or more containers before the containers are rotated around a fixed axis. Usually, 30-month-olds fail to find the hidden object after it was rotated by 180°. We examined whether visual discriminability of the containers improves 30-month-olds’ success in this task and whether children perform better after 90° than after 180° rotations. Two potential hiding containers with same or different colors were placed on a board that was rotated by 90° or 180° in a within-subjects design. Children (N = 29) performed above chance level in all four conditions. Their overall success in finding the object did not improve by differently colored containers. However, different colors prevented children from showing an inhibition bias in 90° rotations, that is, choosing the empty container more often when it was located close to them than when it was farther away: This bias emerged in the same colors condition but not in the different colors condition. Results are discussed in view of particular challenges that might facilitate or deteriorate spatial rotation tasks for young children. PMID:27812346

The Effects of Visual Discriminability and Rotation Angle on 30-Month-Olds' Search Performance in Spatial Rotation Tasks.

PubMed

Ebersbach, Mirjam; Nawroth, Christian

2016-01-01

Tracking objects that are hidden and then moved is a crucial ability related to object permanence, which develops across several stages in early childhood. In spatial rotation tasks, children observe a target object that is hidden in one of two or more containers before the containers are rotated around a fixed axis. Usually, 30-month-olds fail to find the hidden object after it was rotated by 180°. We examined whether visual discriminability of the containers improves 30-month-olds' success in this task and whether children perform better after 90° than after 180° rotations. Two potential hiding containers with same or different colors were placed on a board that was rotated by 90° or 180° in a within-subjects design. Children ( N = 29) performed above chance level in all four conditions. Their overall success in finding the object did not improve by differently colored containers. However, different colors prevented children from showing an inhibition bias in 90° rotations, that is, choosing the empty container more often when it was located close to them than when it was farther away: This bias emerged in the same colors condition but not in the different colors condition. Results are discussed in view of particular challenges that might facilitate or deteriorate spatial rotation tasks for young children.

Multi-level manual and autonomous control superposition for intelligent telerobot

NASA Technical Reports Server (NTRS)

Hirai, Shigeoki; Sato, T.

1989-01-01

Space telerobots are recognized to require cooperation with human operators in various ways. Multi-level manual and autonomous control superposition in telerobot task execution is described. The object model, the structured master-slave manipulation system, and the motion understanding system are proposed to realize the concept. The object model offers interfaces for task level and object level human intervention. The structured master-slave manipulation system offers interfaces for motion level human intervention. The motion understanding system maintains the consistency of the knowledge through all the levels which supports the robot autonomy while accepting the human intervention. The superposing execution of the teleoperational task at multi-levels realizes intuitive and robust task execution for wide variety of objects and in changeful environment. The performance of several examples of operating chemical apparatuses is shown.

Drafting and Design Technology Curriculum Guide.

ERIC Educational Resources Information Center

Idaho State Dept. of Education, Boise. Div. of Vocational Education.

This document provides lists of tasks, performance objectives, and enabling objectives for 1,800 hours of postsecondary instruction or 900 hours of secondary instruction in the drafting and design technology program. Following a list of tasks and an explanation of the program, the bulk of the document consists of 25 modules, each of which is a…

How age affects memory task performance in clinically normal hearing persons.

PubMed

Vercammen, Charlotte; Goossens, Tine; Wouters, Jan; van Wieringen, Astrid

2017-05-01

The main objective of this study is to investigate memory task performance in different age groups, irrespective of hearing status. Data are collected on a short-term memory task (WAIS-III Digit Span forward) and two working memory tasks (WAIS-III Digit Span backward and the Reading Span Test). The tasks are administered to young (20-30 years, n = 56), middle-aged (50-60 years, n = 47), and older participants (70-80 years, n = 16) with normal hearing thresholds. All participants have passed a cognitive screening task (Montreal Cognitive Assessment (MoCA)). Young participants perform significantly better than middle-aged participants, while middle-aged and older participants perform similarly on the three memory tasks. Our data show that older clinically normal hearing persons perform equally well on the memory tasks as middle-aged persons. However, even under optimal conditions of preserved sensory processing, changes in memory performance occur. Based on our data, these changes set in before middle age.

Multiple task performance as a predictor of the potential of air traffic controller trainees : a followup study.

DOT National Transportation Integrated Search

1974-11-01

Two hundred and twenty-nine air traffic controller trainees were tested on the CAMI Multiple Task Performance Battery. The battery provides objective measures of monitoring, arithmetical skills, visual discrimination, and group problem solving. The c...

Attention and reach-to-grasp movements in Parkinson's disease.

PubMed

Lu, Cathy; Bharmal, Aamir; Kiss, Zelma H; Suchowersky, Oksana; Haffenden, Angela M

2010-08-01

The role of attention in grasping movements directed at common objects has not been examined in Parkinson's disease (PD), though these movements are critical to activities of daily living. Our primary objective was to determine whether patients with PD demonstrate automaticity in grasping movements directed toward common objects. Automaticity is assumed when tasks can be performed with little or no interference from concurrent tasks. Grasping performance in three patient groups (newly diagnosed, moderate, and advanced/surgically treated PD) on and off of their medication or deep brain stimulation was compared to performance in an age-matched control group. Automaticity was demonstrated by the absence of a decrement in grasping performance when attention was consumed by a concurrent spatial-visualization task. Only the control group and newly diagnosed PD group demonstrated automaticity in their grasping movements. The moderate and advanced PD groups did not demonstrate automaticity. Furthermore, the well-known effects of pharmacotherapy and surgical intervention on movement speed and muscle activation patterns did not appear to reduce the impact of attention-demanding tasks on grasping movements in those with moderate to advanced PD. By the moderate stage of PD, grasping is an attention-demanding process; this change is not ameliorated by dopaminergic or surgical treatments. These findings have important implications for activities of daily living, as devoting attention to the simplest of daily tasks would interfere with complex activities and potentially exacerbate fatigue.

Similarity relations in visual search predict rapid visual categorization

PubMed Central

Mohan, Krithika; Arun, S. P.

2012-01-01

How do we perform rapid visual categorization?It is widely thought that categorization involves evaluating the similarity of an object to other category items, but the underlying features and similarity relations remain unknown. Here, we hypothesized that categorization performance is based on perceived similarity relations between items within and outside the category. To this end, we measured the categorization performance of human subjects on three diverse visual categories (animals, vehicles, and tools) and across three hierarchical levels (superordinate, basic, and subordinate levels among animals). For the same subjects, we measured their perceived pair-wise similarities between objects using a visual search task. Regardless of category and hierarchical level, we found that the time taken to categorize an object could be predicted using its similarity to members within and outside its category. We were able to account for several classic categorization phenomena, such as (a) the longer times required to reject category membership; (b) the longer times to categorize atypical objects; and (c) differences in performance across tasks and across hierarchical levels. These categorization times were also accounted for by a model that extracts coarse structure from an image. The striking agreement observed between categorization and visual search suggests that these two disparate tasks depend on a shared coarse object representation. PMID:23092947

The relation of object naming and other visual speech production tasks: a large scale voxel-based morphometric study.

PubMed

Lau, Johnny King L; Humphreys, Glyn W; Douis, Hassan; Balani, Alex; Bickerton, Wai-Ling; Rotshtein, Pia

2015-01-01

We report a lesion-symptom mapping analysis of visual speech production deficits in a large group (280) of stroke patients at the sub-acute stage (<120 days post-stroke). Performance on object naming was evaluated alongside three other tests of visual speech production, namely sentence production to a picture, sentence reading and nonword reading. A principal component analysis was performed on all these tests' scores and revealed a 'shared' component that loaded across all the visual speech production tasks and a 'unique' component that isolated object naming from the other three tasks. Regions for the shared component were observed in the left fronto-temporal cortices, fusiform gyrus and bilateral visual cortices. Lesions in these regions linked to both poor object naming and impairment in general visual-speech production. On the other hand, the unique naming component was potentially associated with the bilateral anterior temporal poles, hippocampus and cerebellar areas. This is in line with the models proposing that object naming relies on a left-lateralised language dominant system that interacts with a bilateral anterior temporal network. Neuropsychological deficits in object naming can reflect both the increased demands specific to the task and the more general difficulties in language processing.

Characterizing age-related decline of recognition memory and brain activation profile in mice.

PubMed

Belblidia, Hassina; Leger, Marianne; Abdelmalek, Abdelouadoud; Quiedeville, Anne; Calocer, Floriane; Boulouard, Michel; Jozet-Alves, Christelle; Freret, Thomas; Schumann-Bard, Pascale

2018-06-01

Episodic memory decline is one of the earlier deficits occurring during normal aging in humans. The question of spatial versus non-spatial sensitivity to age-related memory decline is of importance for a full understanding of these changes. Here, we characterized the effect of normal aging on both non-spatial (object) and spatial (object location) memory performances as well as on associated neuronal activation in mice. Novel-object (NOR) and object-location (OLR) recognition tests, respectively assessing the identity and spatial features of object memory, were examined at different ages. We show that memory performances in both tests were altered by aging as early as 15 months of age: NOR memory was partially impaired whereas OLR memory was found to be fully disrupted at 15 months of age. Brain activation profiles were assessed for both tests using immunohistochemical detection of c-Fos (neuronal activation marker) in 3and 15 month-old mice. Normal performances in NOR task by 3 month-old mice were associated to an activation of the hippocampus and a trend towards an activation in the perirhinal cortex, in a way that did significantly differ with 15 month-old mice. During OLR task, brain activation took place in the hippocampus in 3 month-old but not significantly in 15 month-old mice, which were fully impaired at this task. These differential alterations of the object- and object-location recognition memory may be linked to differential alteration of the neuronal networks supporting these tasks. Copyright © 2018 Elsevier Inc. All rights reserved.

Bindings in working memory: The role of object-based attention.

PubMed

Gao, Zaifeng; Wu, Fan; Qiu, Fangfang; He, Kaifeng; Yang, Yue; Shen, Mowei

2017-02-01

Over the past decade, it has been debated whether retaining bindings in working memory (WM) requires more attention than retaining constituent features, focusing on domain-general attention and space-based attention. Recently, we proposed that retaining bindings in WM needs more object-based attention than retaining constituent features (Shen, Huang, & Gao, 2015, Journal of Experimental Psychology: Human Perception and Performance, doi: 10.1037/xhp0000018 ). However, only unitized visual bindings were examined; to establish the role of object-based attention in retaining bindings in WM, more emperical evidence is required. We tested 4 new bindings that had been suggested requiring no more attention than the constituent features in the WM maintenance phase: The two constituent features of binding were stored in different WM modules (cross-module binding, Experiment 1), from auditory and visual modalities (cross-modal binding, Experiment 2), or temporally (cross-time binding, Experiments 3) or spatially (cross-space binding, Experiments 4-6) separated. In the critical condition, we added a secondary object feature-report task during the delay interval of the change-detection task, such that the secondary task competed for object-based attention with the to-be-memorized stimuli. If more object-based attention is required for retaining bindings than for retaining constituent features, the secondary task should impair the binding performance to a larger degree relative to the performance of constituent features. Indeed, Experiments 1-6 consistently revealed a significantly larger impairment for bindings than for the constituent features, suggesting that object-based attention plays a pivotal role in retaining bindings in WM.

Performance on the Iowa gambling task is related to magnitude of weight loss and salivary cortisol in a diet-induced weight loss intervention in overweight women

USDA-ARS?s Scientific Manuscript database

The overall objective of this study was to examine the relationship between executive function, specifically decision making, and weight loss. We used the Iowa Gambling Task (IGT) to characterize decision making and compared performance on this task to weight loss in obese women (n=29) participatin...

Paying for performance: Performance incentives increase desire for the reward object.

PubMed

Hur, Julia D; Nordgren, Loran F

2016-09-01

The current research examines how exposure to performance incentives affects one's desire for the reward object. We hypothesized that the flexible nature of performance incentives creates an attentional fixation on the reward object (e.g., money), which leads people to become more desirous of the rewards. Results from 5 laboratory experiments and 1 large-scale field study provide support for this prediction. When performance was incentivized with monetary rewards, participants reported being more desirous of money (Study 1), put in more effort to earn additional money in an ensuing task (Study 2), and were less willing to donate money to charity (Study 4). We replicated the result with nonmonetary rewards (Study 5). We also found that performance incentives increased attention to the reward object during the task, which in part explains the observed effects (Study 6). A large-scale field study replicated these findings in a real-world setting (Study 7). One laboratory experiment failed to replicate (Study 3). (PsycINFO Database Record (c) 2016 APA, all rights reserved).

Role of the parahippocampal cortex in memory for the configuration but not the identity of objects: converging evidence from patients with selective thermal lesions and fMRI.

PubMed

Bohbot, Véronique D; Allen, John J B; Dagher, Alain; Dumoulin, Serge O; Evans, Alan C; Petrides, Michael; Kalina, Miroslav; Stepankova, Katerina; Nadel, Lynn

2015-01-01

The parahippocampal cortex and hippocampus are brain structures known to be involved in memory. However, the unique contribution of the parahippocampal cortex remains unclear. The current study investigates memory for object identity and memory of the configuration of objects in patients with small thermo-coagulation lesions to the hippocampus or the parahippocampal cortex. Results showed that in contrast to control participants and patients with damage to the hippocampus leaving the parahippocampal cortex intact, patients with lesions that included the right parahippocampal cortex (RPH) were severely impaired on a task that required learning the spatial configuration of objects on a computer screen; these patients, however, were not impaired at learning the identity of objects. Conversely, we found that patients with lesions to the right hippocampus (RH) or left hippocampus (LH), sparing the parahippocampal cortex, performed just as well as the control participants. Furthermore, they were not impaired on the object identity task. In the functional Magnetic Resonance Imaging (fMRI) experiment, healthy young adults performed the same tasks. Consistent with the findings of the lesion study, the fMRI results showed significant activity in the RPH in the memory for the spatial configuration condition, but not memory for object identity. Furthermore, the pattern of fMRI activity measured in the baseline control conditions decreased specifically in the parahippocampal cortex as a result of the experimental task, providing evidence for task specific repetition suppression. In summary, while our previous studies demonstrated that the hippocampus is critical to the construction of a cognitive map, both the lesion and fMRI studies have shown an involvement of the RPH for learning spatial configurations of objects but not object identity, and that this takes place independent of the hippocampus.

Object-Based Attention Overrides Perceptual Load to Modulate Visual Distraction

ERIC Educational Resources Information Center

Cosman, Joshua D.; Vecera, Shaun P.

2012-01-01

The ability to ignore task-irrelevant information and overcome distraction is central to our ability to efficiently carry out a number of tasks. One factor shown to strongly influence distraction is the perceptual load of the task being performed; as the perceptual load of task-relevant information processing increases, the likelihood that…

Contrasting Complement Control, Temporal Adjunct Control and Controlled Verbal Gerund Subjects in ASD: The Role of Contextual Cues in Reference Assignment.

PubMed

Janke, Vikki; Perovic, Alexandra

2017-01-01

This study examines two complex syntactic dependencies (complement control and sentence-final temporal adjunct control) and one pragmatic dependency (controlled verbal gerund subjects) in children with ASD. Sixteen high-functioning (HFA) children (aged 6-16) with a diagnosis of autism and no language impairment, matched on age, gender and non-verbal MA to one TD control group, and on age, gender and verbal MA to another TD control group, undertook three picture-selection tasks. Task 1 measured their base-line interpretations of the empty categories ( ec ). Task 2 preceded these sentence sets with a weakly established topic cueing an alternative referent and Task 3 with a strongly established topic cueing an alternative referent. In complement control (Ron persuaded Hermione ec to kick the ball) and sentence-final temporal adjunct control (Harry tapped Luna while ec feeding the owl), the reference of the ec is argued to be related obligatorily to the object and subject respectively. In controlled verbal-gerund subjects (VGS) ( ec Rowing the boat clumsily made Luna seasick), the ec 's reference is resolved pragmatically. Referent choices across the three tasks were compared. TD children chose the object uniformly in complement control across all tasks but in adjunct control, preferences shifted toward the object in Task 3. In controlled VGSs, they exhibited a strong preference for an internal-referent interpretation in Task 1, which shifted in the direction of the cues in Tasks 2 and 3. HFA children gave a mixed performance. They patterned with their TD counterparts on complement control and controlled VGSs but performed marginally differently on adjunct control: no TD groups were influenced by the weakly established topic in Task 2 but all groups were influenced by the strongly established topic in Task 3. HFA children were less influenced than the TD children, resulting in their making fewer object choices overall but revealing parallel patterns of performance. In this first study of three sub-types of control in ASD, we demonstrate that HFA children consult the same pragmatic cues to the same degree as TD children, in spite of the diverse pragmatic deficits reported for this population.

Contrasting Complement Control, Temporal Adjunct Control and Controlled Verbal Gerund Subjects in ASD: The Role of Contextual Cues in Reference Assignment

PubMed Central

Janke, Vikki; Perovic, Alexandra

2017-01-01

This study examines two complex syntactic dependencies (complement control and sentence-final temporal adjunct control) and one pragmatic dependency (controlled verbal gerund subjects) in children with ASD. Sixteen high-functioning (HFA) children (aged 6–16) with a diagnosis of autism and no language impairment, matched on age, gender and non-verbal MA to one TD control group, and on age, gender and verbal MA to another TD control group, undertook three picture-selection tasks. Task 1 measured their base-line interpretations of the empty categories (ec). Task 2 preceded these sentence sets with a weakly established topic cueing an alternative referent and Task 3 with a strongly established topic cueing an alternative referent. In complement control (Ron persuaded Hermione ec to kick the ball) and sentence-final temporal adjunct control (Harry tapped Luna while ec feeding the owl), the reference of the ec is argued to be related obligatorily to the object and subject respectively. In controlled verbal-gerund subjects (VGS) (ec Rowing the boat clumsily made Luna seasick), the ec's reference is resolved pragmatically. Referent choices across the three tasks were compared. TD children chose the object uniformly in complement control across all tasks but in adjunct control, preferences shifted toward the object in Task 3. In controlled VGSs, they exhibited a strong preference for an internal-referent interpretation in Task 1, which shifted in the direction of the cues in Tasks 2 and 3. HFA children gave a mixed performance. They patterned with their TD counterparts on complement control and controlled VGSs but performed marginally differently on adjunct control: no TD groups were influenced by the weakly established topic in Task 2 but all groups were influenced by the strongly established topic in Task 3. HFA children were less influenced than the TD children, resulting in their making fewer object choices overall but revealing parallel patterns of performance. In this first study of three sub-types of control in ASD, we demonstrate that HFA children consult the same pragmatic cues to the same degree as TD children, in spite of the diverse pragmatic deficits reported for this population. PMID:28400743

Temporally flexible feedback signal to foveal cortex for peripheral object recognition

PubMed Central

Fan, Xiaoxu; Wang, Lan; Shao, Hanyu; Kersten, Daniel; He, Sheng

2016-01-01

Recent studies have shown that information from peripherally presented images is present in the human foveal retinotopic cortex, presumably because of feedback signals. We investigated this potential feedback signal by presenting noise in fovea at different object–noise stimulus onset asynchronies (SOAs), whereas subjects performed a discrimination task on peripheral objects. Results revealed a selective impairment of performance when foveal noise was presented at 250-ms SOA, but only for tasks that required comparing objects’ spatial details, suggesting a task- and stimulus-dependent foveal processing mechanism. Critically, the temporal window of foveal processing was shifted when mental rotation was required for the peripheral objects, indicating that the foveal retinotopic processing is not automatically engaged at a fixed time following peripheral stimulation; rather, it occurs at a stage when detailed information is required. Moreover, fMRI measurements using multivoxel pattern analysis showed that both image and object category-relevant information of peripheral objects was represented in the foveal cortex. Taken together, our results support the hypothesis of a temporally flexible feedback signal to the foveal retinotopic cortex when discriminating objects in the visual periphery. PMID:27671651

Memory for faces and objects by deaf and hearing signers and hearing nonsigners.

PubMed

Arnold, P; Murray, C

1998-07-01

The memory of 11 deaf and 11 hearing British Sign Language users and 11 hearing nonsigners for pictures of faces of and verbalizable objects was measured using the game Concentration. The three groups performed at the same level for the objects. In contrast the deaf signers were better for faces than the hearing signers, who in turn were superior to the hearing nonsigners, who were the worst. Three hypotheses were made: That there would be no significant difference in terms of the number of attempts between the three groups on the verbalizable object task, that the hearing and deaf signers would demonstrate superior performance to that of the hearing nonsigners on the matching faces task, and that the hearing and deaf signers would exhibit similar performance levels on the matching faces task. The first two hypotheses were supported, but the third was not. Deaf signers were found to be superior for memory for faces to hearing signers and hearing nonsigners. Possible explanations for the findings are discussed, including the possibility that deafness and the long use of sign language have additive effects.

Computerized training management system

DOEpatents

Rice, H.B.; McNair, R.C.; White, K.; Maugeri, T.

1998-08-04

A Computerized Training Management System (CTMS) is disclosed for providing a procedurally defined process that is employed to develop accreditable performance based training programs for job classifications that are sensitive to documented regulations and technical information. CTMS is a database that links information needed to maintain a five-phase approach to training-analysis, design, development, implementation, and evaluation independent of training program design. CTMS is designed using R-Base{trademark}, an-SQL compliant software platform. Information is logically entered and linked in CTMS. Each task is linked directly to a performance objective, which, in turn, is linked directly to a learning objective; then, each enabling objective is linked to its respective test items. In addition, tasks, performance objectives, enabling objectives, and test items are linked to their associated reference documents. CTMS keeps all information up to date since it automatically sorts, files and links all data; CTMS includes key word and reference document searches. 18 figs.

Computerized training management system

DOEpatents

Rice, Harold B.; McNair, Robert C.; White, Kenneth; Maugeri, Terry

1998-08-04

A Computerized Training Management System (CTMS) for providing a procedurally defined process that is employed to develop accreditable performance based training programs for job classifications that are sensitive to documented regulations and technical information. CTMS is a database that links information needed to maintain a five-phase approach to training-analysis, design, development, implementation, and evaluation independent of training program design. CTMS is designed using R-Base.RTM., an-SQL compliant software platform. Information is logically entered and linked in CTMS. Each task is linked directly to a performance objective, which, in turn, is linked directly to a learning objective; then, each enabling objective is linked to its respective test items. In addition, tasks, performance objectives, enabling objectives, and test items are linked to their associated reference documents. CTMS keeps all information up to date since it automatically sorts, files and links all data; CTMS includes key word and reference document searches.

Vibrotactile grasping force and hand aperture feedback for myoelectric forearm prosthesis users.

PubMed

Witteveen, Heidi J B; Rietman, Hans S; Veltink, Peter H

2015-06-01

User feedback about grasping force and hand aperture is very important in object handling with myoelectric forearm prostheses but is lacking in current prostheses. Vibrotactile feedback increases the performance of healthy subjects in virtual grasping tasks, but no extensive validation on potential users has been performed. Investigate the performance of upper-limb loss subjects in grasping tasks with vibrotactile stimulation, providing hand aperture, and grasping force feedback. Cross-over trial. A total of 10 subjects with upper-limb loss performed virtual grasping tasks while perceiving vibrotactile feedback. Hand aperture feedback was provided through an array of coin motors and grasping force feedback through a single miniature stimulator or an array of coin motors. Objects with varying sizes and weights had to be grasped by a virtual hand. Percentages correctly applied hand apertures and correct grasping force levels were all higher for the vibrotactile feedback condition compared to the no-feedback condition. With visual feedback, the results were always better compared to the vibrotactile feedback condition. Task durations were comparable for all feedback conditions. Vibrotactile grasping force and hand aperture feedback improves grasping performance of subjects with upper-limb loss. However, it should be investigated whether this is of additional value in daily-life tasks. This study is a first step toward the implementation of sensory vibrotactile feedback for users of myoelectric forearm prostheses. Grasping force feedback is crucial for optimal object handling, and hand aperture feedback is essential for reduction of required visual attention. Grasping performance with feedback is evaluated for the potential users. © The International Society for Prosthetics and Orthotics 2014.

Orbital prefrontal cortex is required for object-in-place scene memory but not performance of a strategy implementation task.

PubMed

Baxter, Mark G; Gaffan, David; Kyriazis, Diana A; Mitchell, Anna S

2007-10-17

The orbital prefrontal cortex is thought to be involved in behavioral flexibility in primates, and human neuroimaging studies have identified orbital prefrontal activation during episodic memory encoding. The goal of the present study was to ascertain whether deficits in strategy implementation and episodic memory that occur after ablation of the entire prefrontal cortex can be ascribed to damage to the orbital prefrontal cortex. Rhesus monkeys were preoperatively trained on two behavioral tasks, the performance of both of which is severely impaired by the disconnection of frontal cortex from inferotemporal cortex. In the strategy implementation task, monkeys were required to learn about two categories of objects, each associated with a different strategy that had to be performed to obtain food reward. The different strategies had to be applied flexibly to optimize the rate of reward delivery. In the scene memory task, monkeys learned 20 new object-in-place discrimination problems in each session. Monkeys were tested on both tasks before and after bilateral ablation of orbital prefrontal cortex. These lesions impaired new scene learning but had no effect on strategy implementation. This finding supports a role for the orbital prefrontal cortex in memory but places limits on the involvement of orbital prefrontal cortex in the representation and implementation of behavioral goals and strategies.

Monovision techniques for telerobots

NASA Technical Reports Server (NTRS)

Goode, P. W.; Carnils, K.

1987-01-01

The primary task of the vision sensor in a telerobotic system is to provide information about the position of the system's effector relative to objects of interest in its environment. The subtasks required to perform the primary task include image segmentation, object recognition, and object location and orientation in some coordinate system. The accomplishment of the vision task requires the appropriate processing tools and the system methodology to effectively apply the tools to the subtasks. The functional structure of the telerobotic vision system used in the Langley Research Center's Intelligent Systems Research Laboratory is discussed as well as two monovision techniques for accomplishing the vision subtasks.

Is Attentional Resource Allocation Across Sensory Modalities Task-Dependent?

PubMed

Wahn, Basil; König, Peter

2017-01-01

Human information processing is limited by attentional resources. That is, via attentional mechanisms, humans select a limited amount of sensory input to process while other sensory input is neglected. In multisensory research, a matter of ongoing debate is whether there are distinct pools of attentional resources for each sensory modality or whether attentional resources are shared across sensory modalities. Recent studies have suggested that attentional resource allocation across sensory modalities is in part task-dependent. That is, the recruitment of attentional resources across the sensory modalities depends on whether processing involves object-based attention (e.g., the discrimination of stimulus attributes) or spatial attention (e.g., the localization of stimuli). In the present paper, we review findings in multisensory research related to this view. For the visual and auditory sensory modalities, findings suggest that distinct resources are recruited when humans perform object-based attention tasks, whereas for the visual and tactile sensory modalities, partially shared resources are recruited. If object-based attention tasks are time-critical, shared resources are recruited across the sensory modalities. When humans perform an object-based attention task in combination with a spatial attention task, partly shared resources are recruited across the sensory modalities as well. Conversely, for spatial attention tasks, attentional processing does consistently involve shared attentional resources for the sensory modalities. Generally, findings suggest that the attentional system flexibly allocates attentional resources depending on task demands. We propose that such flexibility reflects a large-scale optimization strategy that minimizes the brain's costly resource expenditures and simultaneously maximizes capability to process currently relevant information.

Controlling an avatar by thought using real-time fMRI

NASA Astrophysics Data System (ADS)

Cohen, Ori; Koppel, Moshe; Malach, Rafael; Friedman, Doron

2014-06-01

Objective. We have developed a brain-computer interface (BCI) system based on real-time functional magnetic resonance imaging (fMRI) with virtual reality feedback. The advantage of fMRI is the relatively high spatial resolution and the coverage of the whole brain; thus we expect that it may be used to explore novel BCI strategies, based on new types of mental activities. However, fMRI suffers from a low temporal resolution and an inherent delay, since it is based on a hemodynamic response rather than electrical signals. Thus, our objective in this paper was to explore whether subjects could perform a BCI task in a virtual environment using our system, and how their performance was affected by the delay. Approach. The subjects controlled an avatar by left-hand, right-hand and leg motion or imagery. The BCI classification is based on locating the regions of interest (ROIs) related with each of the motor classes, and selecting the ROI with maximum average values online. The subjects performed a cue-based task and a free-choice task, and the analysis includes evaluation of the performance as well as subjective reports. Main results. Six subjects performed the task with high accuracy when allowed to move their fingers and toes, and three subjects achieved high accuracy using imagery alone. In the cue-based task the accuracy was highest 8-12 s after the trigger, whereas in the free-choice task the subjects performed best when the feedback was provided 6 s after the trigger. Significance. We show that subjects are able to perform a navigation task in a virtual environment using an fMRI-based BCI, despite the hemodynamic delay. The same approach can be extended to other mental tasks and other brain areas.

Repeated Δ9-Tetrahydrocannabinol Exposure in Adolescent Monkeys: Persistent Effects Selective for Spatial Working Memory

PubMed Central

Verrico, Christopher D.; Gu, Hong; Peterson, Melanie L.; Sampson, Allan R.; Lewis, David A.

2014-01-01

Objective Epidemiological findings suggest that, relative to adults, adolescents are more vulnerable to the adverse persistent effects of cannabis on working memory. However, the potential confounds inherent in human studies preclude direct determination of a cause-and-effect relationship between adolescent cannabis use and heightened susceptibility to persistent working memory impairments. Consequently, the authors examined the effects of repeated exposure to Δ9-tetrahydrocannabinol (THC) on performance of spatial and object working memory tasks in adolescent monkeys. Method Seven pairs of male adolescent rhesus monkeys, matched for baseline cognitive performance, received vehicle or THC intravenously 5 days/week for 6 months. Performance on spatial and object memory tasks was assessed 23 or 71 hours after drug administration throughout the study. In addition, acute effects on working memory were also assessed at the beginning and end of the 6-month period. Results Relative to the vehicle-exposed control animals, those with repeated THC exposure had a blunted trajectory of accuracy improvements on the spatial working memory task in a delay-dependent manner. Accuracy improvements on the object working memory task did not differ between groups. Relative to the acute effects of THC on working memory at the beginning of the study, neither sensitivity nor tolerance was evident after 6 months of THC exposure. Conclusions Because maturation of performance is later for spatial than for object working memory, these findings suggest that persistent effects of THC on cognitive abilities are more evident when exposure coincides with the developmental stage during which the underlying neural circuits are actively maturing. PMID:24577206

Spatial Reasoning with External Visualizations: What Matters Is What You See, Not whether You Interact

ERIC Educational Resources Information Center

Keehner, Madeleine; Hegarty, Mary; Cohen, Cheryl; Khooshabeh, Peter; Montello, Daniel R.

2008-01-01

Three experiments examined the effects of interactive visualizations and spatial abilities on a task requiring participants to infer and draw cross sections of a three-dimensional (3D) object. The experiments manipulated whether participants could interactively control a virtual 3D visualization of the object while performing the task, and…

DEVELOPMENT OF PROCEDURES FOR DERIVING TRAINING OBJECTIVES FOR JUNIOR OFFICER JOBS.

ERIC Educational Resources Information Center

AMMERMAN, HARRY L.

A SYSTEMATIC METHOD WAS DEVELOPED TO BE USED BY SERVICE SCHOOL PERSONNEL IN PREPARING JOB-ORIENTED TRAINING OBJECTIVES FOR JUNIOR OFFICERS, PRIMARILY IN THE FORM OF BEHAVIORAL STATEMENTS OF PERFORMANCE EXPECTED AFTER TRAINING. THE PROCEDURES DEVELOPED WERE (1) LISTING ALL TASKS FOR A JOB, (2) SELECTING TASKS FOR SOME FORMAL TRAINING, (3)…

Written object naming, spelling to dictation, and immediate copying: Different tasks, different pathways?

PubMed

Bonin, Patrick; Méot, Alain; Lagarrigue, Aurélie; Roux, Sébastien

2015-01-01

We report an investigation of cross-task comparisons of handwritten latencies in written object naming, spelling to dictation, and immediate copying. In three separate sessions, adults had to write down a list of concrete nouns from their corresponding pictures (written naming), from their spoken (spelling to dictation) and from their visual presentation (immediate copying). Linear mixed models without random slopes were performed on the latencies in order to study and compare within-task fixed effects. By-participants random slopes were then included to investigate individual differences within and across tasks. Overall, the findings suggest that written naming, spelling to dictation, and copying all involve a lexical pathway, but that written naming relies on this pathway more than the other two tasks do. Only spelling to dictation strongly involves a nonlexical pathway. Finally, the analyses performed at the level of participants indicate that, depending on the type of task, the slower participants are more or less influenced by certain psycholinguistic variables.

Stimulus-response correspondence in go-nogo and choice tasks: Are reactions altered by the presence of an irrelevant salient object?

PubMed

Lien, Mei-Ching; Pedersen, Logan; Proctor, Robert W

2016-11-01

In 2-choice tasks, responses are faster when stimulus location corresponds to response location, even when stimulus location is irrelevant. Dolk et al. (J Exp Psychol Hum Percept Perform 39:1248-1260, 2013a) found this stimulus-response correspondence effect with a single response location in a go-nogo task when an irrelevant Japanese waving cat was present. They argued that salient objects trigger spatial coding of the response relative to that object. We examined this claim using both behavioral and lateralized readiness potential (LRP) measures. In Experiment 1 participants determined the pitch of a left- or right-positioned tone, whereas in Experiment 2 they determined the color of a dot within a centrally located hand pointing left, right, or straight ahead. In both experiments, participants performed a go-nogo task with the right-index finger and a 2-choice task with both index fingers, with a left-positioned Japanese waving cat present or absent. For the go-nogo task, the cat induced a correspondence effect on response times (RT) to the tones (Experiment 1) but not the visual stimuli (Experiment 2). For the 2-choice task, a correspondence effect was evident in all conditions in both experiments. Cat's presence/absence did not significantly modulate the effect for right and left responses, although there was a trend toward increased RT and LRP for right responses in Experiment 1. The results imply that a salient, irrelevant object could provide a reference frame for response coding when attention is available to process it, as is likely in an auditory task (Experiment 1) but not a visual task (Experiment 2).

Effect of aging on dynamic postural stability and variability during a multi-directional lean and reach object transportation task.

PubMed

Huntley, Andrew H; Zettel, John L; Vallis, Lori Ann

2016-01-01

A "reach and transport object" task that represents common activities of daily living may provide improved insight into dynamic postural stability and movement variability deficits in older adults compared to previous lean to reach and functional reach tests. Healthy young and older, community dwelling adults performed three same elevation object transport tasks and two multiple elevation object transport tasks under two self-selected speeds, self-paced and fast-paced. Dynamic postural stability and movement variability was quantified by whole-body center of mass motion. Older adults demonstrated significant decrements in frontal plane stability during the multiple elevation tasks while exhibiting the same movement variability as their younger counterparts, regardless of task speed. Interestingly, older adults did not exhibit a tradeoff in maneuverability in favour of maintaining stability throughout the tasks, as has previously been reported. In conclusion, the multi-planar, ecologically relevant tasks employed in the current study were specific enough to elucidate decrements in dynamic stability, and thus may be useful for assessing fall risk in older adults with suspected postural instability. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Fitts’ Law in the Control of Isometric Grip Force With Naturalistic Targets

PubMed Central

Thumser, Zachary C.; Slifkin, Andrew B.; Beckler, Dylan T.; Marasco, Paul D.

2018-01-01

Fitts’ law models the relationship between amplitude, precision, and speed of rapid movements. It is widely used to quantify performance in pointing tasks, study human-computer interaction, and generally to understand perceptual-motor information processes, including research to model performance in isometric force production tasks. Applying Fitts’ law to an isometric grip force task would allow for quantifying grasp performance in rehabilitative medicine and may aid research on prosthetic control and design. We examined whether Fitts’ law would hold when participants attempted to accurately produce their intended force output while grasping a manipulandum when presented with images of various everyday objects (we termed this the implicit task). Although our main interest was the implicit task, to benchmark it and establish validity, we examined performance against a more standard visual feedback condition via a digital force-feedback meter on a video monitor (explicit task). Next, we progressed from visual force feedback with force meter targets to the same targets without visual force feedback (operating largely on feedforward control with tactile feedback). This provided an opportunity to see if Fitts’ law would hold without vision, and allowed us to progress toward the more naturalistic implicit task (which does not include visual feedback). Finally, we changed the nature of the targets from requiring explicit force values presented as arrows on a force-feedback meter (explicit targets) to the more naturalistic and intuitive target forces implied by images of objects (implicit targets). With visual force feedback the relation between task difficulty and the time to produce the target grip force was predicted by Fitts’ law (average r2 = 0.82). Without vision, average grip force scaled accurately although force variability was insensitive to the target presented. In contrast, images of everyday objects generated more reliable grip forces without the visualized force meter. In sum, population means were well-described by Fitts’ law for explicit targets with vision (r2 = 0.96) and implicit targets (r2 = 0.89), but not as well-described for explicit targets without vision (r2 = 0.54). Implicit targets should provide a realistic see-object-squeeze-object test using Fitts’ law to quantify the relative speed-accuracy relationship of any given grasper. PMID:29773999

MoDOT pavement preservation research program volume VII, re-calibration of triggers and performance models.

DOT National Transportation Integrated Search

2015-10-01

The objective of this task is to develop the concept and framework for a procedure to routinely create, re-calibrate, and update the : Trigger Tables and Performance Models. The scope of work for Task 6 includes a limited review of the recent pavemen...

A steady state visually evoked potential investigation of memory and ageing.

PubMed

Macpherson, Helen; Pipingas, Andrew; Silberstein, Richard

2009-04-01

Old age is generally accompanied by a decline in memory performance. Specifically, neuroimaging and electrophysiological studies have revealed that there are age-related changes in the neural correlates of episodic and working memory. This study investigated age-associated changes in the steady state visually evoked potential (SSVEP) amplitude and latency associated with memory performance. Participants were 15 older (59-67 years) and 14 younger (20-30 years) adults who performed an object working memory (OWM) task and a contextual recognition memory (CRM) task, whilst the SSVEP was recorded from 64 electrode sites. Retention of a single object in the low demand OWM task was characterised by smaller frontal SSVEP amplitude and latency differences in older adults than in younger adults, indicative of an age-associated reduction in neural processes. Recognition of visual images in the more difficult CRM task was accompanied by larger, more sustained SSVEP amplitude and latency decreases over temporal parietal regions in older adults. In contrast, the more transient, frontally mediated pattern of activity demonstrated by younger adults suggests that younger and older adults utilize different neural resources to perform recognition judgements. The results provide support for compensatory processes in the aging brain; at lower task demands, older adults demonstrate reduced neural activity, whereas at greater task demands neural activity is increased.

Mutual interference between statistical summary perception and statistical learning.

PubMed

Zhao, Jiaying; Ngo, Nhi; McKendrick, Ryan; Turk-Browne, Nicholas B

2011-09-01

The visual system is an efficient statistician, extracting statistical summaries over sets of objects (statistical summary perception) and statistical regularities among individual objects (statistical learning). Although these two kinds of statistical processing have been studied extensively in isolation, their relationship is not yet understood. We first examined how statistical summary perception influences statistical learning by manipulating the task that participants performed over sets of objects containing statistical regularities (Experiment 1). Participants who performed a summary task showed no statistical learning of the regularities, whereas those who performed control tasks showed robust learning. We then examined how statistical learning influences statistical summary perception by manipulating whether the sets being summarized contained regularities (Experiment 2) and whether such regularities had already been learned (Experiment 3). The accuracy of summary judgments improved when regularities were removed and when learning had occurred in advance. In sum, calculating summary statistics impeded statistical learning, and extracting statistical regularities impeded statistical summary perception. This mutual interference suggests that statistical summary perception and statistical learning are fundamentally related.

The effects of display-control I/O, compatibility, and integrality on dual-task performance and subjective workload

NASA Technical Reports Server (NTRS)

Tsang, Pamela S.; Hart, Sandra G.; Vidulich, Michael A.

1987-01-01

The utility of speech technology was evaluated in terms of three dual task principles: resource competition between the time shared tasks, stimulus central processing response compatibility, and task integrality. Empirical support for these principles was reviewed. Two studies investigating the interactive effects of the three principles were described. Objective performance and subjective workload ratings for both single and dual tasks were examined. It was found that the single task measures were not necessarily good predictors for the dual task measures. It was shown that all three principles played an important role in determining an optimal task configuration. This was reflected in both the performance measures and the subjective measures. Therefore, consideration of all three principles is required to insure proper use of speech technology in a complex environment.

Long-term repetition priming and semantic interference in a lexical-semantic matching task: tapping the links between object names and colors.

PubMed

Lloyd-Jones, Toby J; Nakabayashi, Kazuyo

2014-01-01

Using a novel paradigm to engage the long-term mappings between object names and the prototypical colors for objects, we investigated the retrieval of object-color knowledge as indexed by long-term priming (the benefit in performance from a prior encounter with the same or a similar stimulus); a process about which little is known. We examined priming from object naming on a lexical-semantic matching task. In the matching task participants encountered a visually presented object name (Experiment 1) or object shape (Experiment 2) paired with either a color patch or color name. The pairings could either match whereby both were consistent with a familiar object (e.g., strawberry and red) or mismatch (strawberry and blue). We used the matching task to probe knowledge about familiar objects and their colors pre-activated during object naming. In particular, we examined whether the retrieval of object-color information was modality-specific and whether this influenced priming. Priming varied with the nature of the retrieval process: object-color priming arose for object names but not object shapes and beneficial effects of priming were observed for color patches whereas inhibitory priming arose with color names. These findings have implications for understanding how object knowledge is retrieved from memory and modified by learning.

An ERP Study on Self-Relevant Object Recognition

ERIC Educational Resources Information Center

Miyakoshi, Makoto; Nomura, Michio; Ohira, Hideki

2007-01-01

We performed an event-related potential study to investigate the self-relevance effect in object recognition. Three stimulus categories were prepared: SELF (participant's own objects), FAMILIAR (disposable and public objects, defined as objects with less-self-relevant familiarity), and UNFAMILIAR (others' objects). The participants' task was to…

Upper limb motor function in young adults with spina bifida and hydrocephalus

PubMed Central

Salman, M. S.; Jewell, D.; Hetherington, R.; Spiegler, B. J.; MacGregor, D. L.; Drake, J. M.; Humphreys, R. P.; Gentili, F.

2011-01-01

Objective The objective of the study was to measure upper limb motor function in young adults with spina bifida meningomyelocele (SBM) and typically developing age peers. Method Participants were 26 young adults with SBM, with a Verbal or Performance IQ score of at least 70 on the Wechsler scales, and 27 age- and gender-matched controls. Four upper limb motor function tasks were performed under four different visual and cognitive challenge conditions. Motor independence was assessed by questionnaire. Results Fewer SBM than control participants obtained perfect posture and rebound scores. The SBM group performed less accurately and was more disrupted by cognitive challenge than controls on limb dysmetria tasks. The SBM group was slower than controls on the diadochokinesis task. Adaptive motor independence was related to one upper limb motor task, arm posture, and upper rather than lower spinal lesions were associated with less motor independence. Conclusions Young adults with SBM have significant limitations in upper limb function and are more disrupted by some challenges while performing upper limb motor tasks. Within the group of young adults with SBM, upper spinal lesions compromise motor independence more than lower spinal lesions. PMID:19672605

The Functional Task Test (FTT): An Interdisciplinary Testing Protocol to Investigate the Factors Underlying Changes in Astronaut Functional Performance

NASA Technical Reports Server (NTRS)

Bloomberg, J. J.; Lawrence, E. L.; Arzeno, N. M.; Buxton, R. E.; Feiveson, A. H.; Kofman, I. S.; Lee, S. M. C.; Mulavara, A. P.; Peters, B. T.; Platts. S. H.;

On the costs of parallel processing in dual-task performance: The case of lexical processing in word production.

PubMed

Paucke, Madlen; Oppermann, Frank; Koch, Iring; Jescheniak, Jörg D

2015-12-01

Previous dual-task picture-naming studies suggest that lexical processes require capacity-limited processes and prevent other tasks to be carried out in parallel. However, studies involving the processing of multiple pictures suggest that parallel lexical processing is possible. The present study investigated the specific costs that may arise when such parallel processing occurs. We used a novel dual-task paradigm by presenting 2 visual objects associated with different tasks and manipulating between-task similarity. With high similarity, a picture-naming task (T1) was combined with a phoneme-decision task (T2), so that lexical processes were shared across tasks. With low similarity, picture-naming was combined with a size-decision T2 (nonshared lexical processes). In Experiment 1, we found that a manipulation of lexical processes (lexical frequency of T1 object name) showed an additive propagation with low between-task similarity and an overadditive propagation with high between-task similarity. Experiment 2 replicated this differential forward propagation of the lexical effect and showed that it disappeared with longer stimulus onset asynchronies. Moreover, both experiments showed backward crosstalk, indexed as worse T1 performance with high between-task similarity compared with low similarity. Together, these findings suggest that conditions of high between-task similarity can lead to parallel lexical processing in both tasks, which, however, does not result in benefits but rather in extra performance costs. These costs can be attributed to crosstalk based on the dual-task binding problem arising from parallel processing. Hence, the present study reveals that capacity-limited lexical processing can run in parallel across dual tasks but only at the expense of extraordinary high costs. (c) 2015 APA, all rights reserved).

Feature-based interference from unattended visual field during attentional tracking in younger and older adults.

PubMed

Störmer, Viola S; Li, Shu-Chen; Heekeren, Hauke R; Lindenberger, Ulman

2011-02-01

The ability to attend to multiple objects that move in the visual field is important for many aspects of daily functioning. The attentional capacity for such dynamic tracking, however, is highly limited and undergoes age-related decline. Several aspects of the tracking process can influence performance. Here, we investigated effects of feature-based interference from distractor objects that appear in unattended regions of the visual field with a hemifield-tracking task. Younger and older participants performed an attentional tracking task in one hemifield while distractor objects were concurrently presented in the unattended hemifield. Feature similarity between objects in the attended and unattended hemifields as well as motion speed and the number of to-be-tracked objects were parametrically manipulated. The results show that increasing feature overlap leads to greater interference from the unattended visual field. This effect of feature-based interference was only present in the slow speed condition, indicating that the interference is mainly modulated by perceptual demands. High-performing older adults showed a similar interference effect as younger adults, whereas low-performing adults showed poor tracking performance overall.

V-TECS Guide for Farm Equipment Mechanic.

ERIC Educational Resources Information Center

McClimon, Hugh P.; And Others

This curriculum guide for a vocational agriculture course in farm equipment mechanics addresses the three domains of learning (psychomotor, cognitive, and affective) while providing job-relevant tasks and suggestions for specific classroom activities for each identified task. This guide provides performance objectives for the following 13 tasks:…

Object permanence in the food-storing coal tit (Periparus ater) and the non-storing great tit (Parus major): Is the mental representation required?

PubMed

Marhounová, Lucie; Frynta, Daniel; Fuchs, Roman; Landová, Eva

2017-05-01

Object permanence is a cognitive ability that enables animals to mentally represent the continuous existence of temporarily hidden objects. Generally, it develops gradually through six qualitative stages, the evolution of which may be connected with some specific ecological and behavioral factors. In birds, the advanced object permanence skills were reported in several storing species of the Corvidae family. In order to test the association between food-storing and achieved performance within the stages, we compared food-storing coal tits (Periparus ater) and nonstoring great tits (Parus major) using an adapted version of Uzgiris & Hunt's Scale 1 tasks. The coal tits significantly outperformed the great tits in searching for completely hidden objects. Most of the great tits could not solve the task when the object disappeared completely. However, the upper limit for both species is likely to be Stage 4. The coal tits could solve problems with simply hidden objects, but they used alternative strategies rather than mental representation when searching for completely hidden objects, especially if choosing between two locations. Our results also suggest that neophobia did not affect the overall performance in the object permanence tasks. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Task-discriminative space-by-time factorization of muscle activity

PubMed Central

Delis, Ioannis; Panzeri, Stefano; Pozzo, Thierry; Berret, Bastien

2015-01-01

Movement generation has been hypothesized to rely on a modular organization of muscle activity. Crucial to this hypothesis is the ability to perform reliably a variety of motor tasks by recruiting a limited set of modules and combining them in a task-dependent manner. Thus far, existing algorithms that extract putative modules of muscle activations, such as Non-negative Matrix Factorization (NMF), identify modular decompositions that maximize the reconstruction of the recorded EMG data. Typically, the functional role of the decompositions, i.e., task accomplishment, is only assessed a posteriori. However, as motor actions are defined in task space, we suggest that motor modules should be computed in task space too. In this study, we propose a new module extraction algorithm, named DsNM3F, that uses task information during the module identification process. DsNM3F extends our previous space-by-time decomposition method (the so-called sNM3F algorithm, which could assess task performance only after having computed modules) to identify modules gauging between two complementary objectives: reconstruction of the original data and reliable discrimination of the performed tasks. We show that DsNM3F recovers the task dependence of module activations more accurately than sNM3F. We also apply it to electromyographic signals recorded during performance of a variety of arm pointing tasks and identify spatial and temporal modules of muscle activity that are highly consistent with previous studies. DsNM3F achieves perfect task categorization without significant loss in data approximation when task information is available and generalizes as well as sNM3F when applied to new data. These findings suggest that the space-by-time decomposition of muscle activity finds robust task-discriminating modular representations of muscle activity and that the insertion of task discrimination objectives is useful for describing the task modulation of module recruitment. PMID:26217213

Task-discriminative space-by-time factorization of muscle activity.

PubMed

Delis, Ioannis; Panzeri, Stefano; Pozzo, Thierry; Berret, Bastien

2015-01-01

Movement generation has been hypothesized to rely on a modular organization of muscle activity. Crucial to this hypothesis is the ability to perform reliably a variety of motor tasks by recruiting a limited set of modules and combining them in a task-dependent manner. Thus far, existing algorithms that extract putative modules of muscle activations, such as Non-negative Matrix Factorization (NMF), identify modular decompositions that maximize the reconstruction of the recorded EMG data. Typically, the functional role of the decompositions, i.e., task accomplishment, is only assessed a posteriori. However, as motor actions are defined in task space, we suggest that motor modules should be computed in task space too. In this study, we propose a new module extraction algorithm, named DsNM3F, that uses task information during the module identification process. DsNM3F extends our previous space-by-time decomposition method (the so-called sNM3F algorithm, which could assess task performance only after having computed modules) to identify modules gauging between two complementary objectives: reconstruction of the original data and reliable discrimination of the performed tasks. We show that DsNM3F recovers the task dependence of module activations more accurately than sNM3F. We also apply it to electromyographic signals recorded during performance of a variety of arm pointing tasks and identify spatial and temporal modules of muscle activity that are highly consistent with previous studies. DsNM3F achieves perfect task categorization without significant loss in data approximation when task information is available and generalizes as well as sNM3F when applied to new data. These findings suggest that the space-by-time decomposition of muscle activity finds robust task-discriminating modular representations of muscle activity and that the insertion of task discrimination objectives is useful for describing the task modulation of module recruitment.

Training Attentional Control Improves Cognitive and Motor Task Performance.

PubMed

Ducrocq, Emmanuel; Wilson, Mark; Vine, Sam; Derakshan, Nazanin

2016-10-01

Attentional control is a necessary function for the regulation of goal-directed behavior. In three experiments we investigated whether training inhibitory control using a visual search task could improve task-specific measures of attentional control and performance. In Experiment 1 results revealed that training elicited a near-transfer effect, improving performance on a cognitive (antisaccade) task assessing inhibitory control. In Experiment 2 an initial far-transfer effect of training was observed on an index of attentional control validated for tennis. The principal aim of Experiment 3 was to expand on these findings by assessing objective gaze measures of inhibitory control during the performance of a tennis task. Training improved inhibitory control and performance when pressure was elevated, confirming the mechanisms by which cognitive anxiety impacts performance. These results suggest that attentional control training can improve inhibition and reduce taskspecific distractibility with promise of transfer to more efficient sporting performance in competitive contexts.

Comparison of oral surgery task performance in a virtual reality surgical simulator and an animal model using objective measures.

PubMed

Ioannou, Ioanna; Kazmierczak, Edmund; Stern, Linda

2015-01-01

The use of virtual reality (VR) simulation for surgical training has gathered much interest in recent years. Despite increasing popularity and usage, limited work has been carried out in the use of automated objective measures to quantify the extent to which performance in a simulator resembles performance in the operating theatre, and the effects of simulator training on real world performance. To this end, we present a study exploring the effects of VR training on the performance of dentistry students learning a novel oral surgery task. We compare the performance of trainees in a VR simulator and in a physical setting involving ovine jaws, using a range of automated metrics derived by motion analysis. Our results suggest that simulator training improved the motion economy of trainees without adverse effects on task outcome. Comparison of surgical technique on the simulator with the ovine setting indicates that simulator technique is similar, but not identical to real world technique.

Metacognitive deficits in categorization tasks in a population with impaired inner speech.

PubMed

Langland-Hassan, Peter; Gauker, Christopher; Richardson, Michael J; Dietz, Aimee; Faries, Frank R

2017-11-01

This study examines the relation of language use to a person's ability to perform categorization tasks and to assess their own abilities in those categorization tasks. A silent rhyming task was used to confirm that a group of people with post-stroke aphasia (PWA) had corresponding covert language production (or "inner speech") impairments. The performance of the PWA was then compared to that of age- and education-matched healthy controls on three kinds of categorization tasks and on metacognitive self-assessments of their performance on those tasks. The PWA showed no deficits in their ability to categorize objects for any of the three trial types (visual, thematic, and categorial). However, on the categorial trials, their metacognitive assessments of whether they had categorized correctly were less reliable than those of the control group. The categorial trials were distinguished from the others by the fact that the categorization could not be based on some immediately perceptible feature or on the objects' being found together in a type of scenario or setting. This result offers preliminary evidence for a link between covert language use and a specific form of metacognition. Copyright © 2017 Elsevier B.V. All rights reserved.

A graphical, rule based robotic interface system

NASA Technical Reports Server (NTRS)

Mckee, James W.; Wolfsberger, John

1988-01-01

The ability of a human to take control of a robotic system is essential in any use of robots in space in order to handle unforeseen changes in the robot's work environment or scheduled tasks. But in cases in which the work environment is known, a human controlling a robot's every move by remote control is both time consuming and frustrating. A system is needed in which the user can give the robotic system commands to perform tasks but need not tell the system how. To be useful, this system should be able to plan and perform the tasks faster than a telerobotic system. The interface between the user and the robot system must be natural and meaningful to the user. A high level user interface program under development at the University of Alabama, Huntsville, is described. A graphical interface is proposed in which the user selects objects to be manipulated by selecting representations of the object on projections of a 3-D model of the work environment. The user may move in the work environment by changing the viewpoint of the projections. The interface uses a rule based program to transform user selection of items on a graphics display of the robot's work environment into commands for the robot. The program first determines if the desired task is possible given the abilities of the robot and any constraints on the object. If the task is possible, the program determines what movements the robot needs to make to perform the task. The movements are transformed into commands for the robot. The information defining the robot, the work environment, and how objects may be moved is stored in a set of data bases accessible to the program and displayable to the user.

Spatial task performance, sex differences, and motion sickness susceptibility.

PubMed

Levine, Max E; Stern, Robert M

2002-10-01

There are substantial individual differences in susceptibility to motion sickness, yet little is known about what mediates these differences. Spatial ability and sex have been suggested as possible factors in this relationship. 89 participants (57 women) were administered a Motion Sickness Questionnaire that assesses motion sickness susceptibility, a Water-level Task that gauges sensitivity to gravitational upright, and a Mental Rotation Task that tests an individual's awareness of how objects typically move in space. Significant sex differences were observed in performance of both the Water-level Task (p<.01), and the Mental Rotation Task (p<.005), with women performing less accurately than men. Women also had significantly higher scores on the Motion Sickness Questionnaire (p<.005). Among men, but not women, significant negative relationships were observed between Water-level Task performance and Motion Sickness Questionnaire score (p<.001) and between Mental Rotation Task performance and Motion Sickness Questionnaire score (p<.005). In conclusion, women performed significantly more poorly than men did on the spatial ability tasks and reported significantly more bouts of motion sickness. In addition, men showed a significant negative relationship between spatial ability and motion sickness susceptibility.

Identifying optimum performance trade-offs using a cognitively bounded rational analysis model of discretionary task interleaving.

PubMed

Janssen, Christian P; Brumby, Duncan P; Dowell, John; Chater, Nick; Howes, Andrew

2011-01-01

We report the results of a dual-task study in which participants performed a tracking and typing task under various experimental conditions. An objective payoff function was used to provide explicit feedback on how participants should trade off performance between the tasks. Results show that participants' dual-task interleaving strategy was sensitive to changes in the difficulty of the tracking task and resulted in differences in overall task performance. To test the hypothesis that people select strategies that maximize payoff, a Cognitively Bounded Rational Analysis model was developed. This analysis evaluated a variety of dual-task interleaving strategies to identify the optimal strategy for maximizing payoff in each condition. The model predicts that the region of optimum performance is different between experimental conditions. The correspondence between human data and the prediction of the optimal strategy is found to be remarkably high across a number of performance measures. This suggests that participants were honing their behavior to maximize payoff. Limitations are discussed. Copyright © 2011 Cognitive Science Society, Inc.

Unexpected Dual Task Benefits on Cycling in Parkinson Disease and Healthy Adults: A Neuro-Behavioral Model

PubMed Central

Altmann, Lori J. P.; Stegemöller, Elizabeth; Hazamy, Audrey A.; Wilson, Jonathan P.; Okun, Michael S.; McFarland, Nikolaus R.; Shukla, Aparna Wagle; Hass, Chris J.

2015-01-01

Background When performing two tasks at once, a dual task, performance on one or both tasks typically suffers. People with Parkinson’s disease (PD) usually experience larger dual task decrements on motor tasks than healthy older adults (HOA). Our objective was to investigate the decrements in cycling caused by performing cognitive tasks with a range of difficulty in people with PD and HOAs. Methods Twenty-eight participants with Parkinson’s disease and 20 healthy older adults completed a baseline cycling task with no secondary tasks and then completed dual task cycling while performing 12 tasks from six cognitive domains representing a wide range of difficulty. Results Cycling was faster during dual task conditions than at baseline, and was significantly faster for six tasks (all p<.02) across both groups. Cycling speed improved the most during the easiest cognitive tasks, and cognitive performance was largely unaffected. Cycling improvement was predicted by task difficulty (p<.001). People with Parkinson’s disease cycled slower (p<.03) and showed reduced dual task benefits (p<.01) than healthy older adults. Conclusions Unexpectedly, participants’ motor performance improved during cognitive dual tasks, which cannot be explained in current models of dual task performance. To account for these findings, we propose a model integrating dual task and acute exercise approaches which posits that cognitive arousal during dual tasks increases resources to facilitate motor and cognitive performance, which is subsequently modulated by motor and cognitive task difficulty. This model can explain both the improvement observed on dual tasks in the current study and more typical dual task findings in other studies. PMID:25970607

The Association of Subjective Workload Dimensions on Quality of Care and Pharmacist Quality of Work Life

PubMed Central

Chui, Michelle A.; Look, Kevin A.; Mott, David A.

2013-01-01

Background Workload has been described both objectively (e.g., number of prescriptions dispensed per pharmacist) as well as subjectively (e.g., pharmacist’s perception of busyness). These approaches might be missing important characteristics of pharmacist workload that have not been previously identified and measured. Objectives To measure the association of community pharmacists’ workload perceptions at three levels (organization, job, and task) with job satisfaction, burnout, and perceived performance of two tasks in the medication dispensing process. Methods A secondary data analysis was performed using cross-sectional survey data collected from Wisconsin (US) community pharmacists. Organization–related workload was measured as staffing adequacy; job-related workload was measured as general and specific job demands; task-related workload was measured as internal and external mental demands. Pharmacists’ perceived task performance was assessed for patient profile review and patient consultation. The survey was administered to a random sample of 500 pharmacists who were asked to opt in if they were a community pharmacist. Descriptive statistics and correlations of study variables were determined. Two structural equation models were estimated to examine relationships between the study variables and perceived task performance. Results From the 224 eligible community pharmacists that agreed to participate, 165 (73.7%) usable surveys were completed and returned. Job satisfaction and job-related monitoring demands had direct positive associations with both dispensing tasks. External task demands were negatively related to perceived patient consultation performance. Indirect effects on both tasks were primarily mediated through job satisfaction, which was positively related to staffing adequacy and cognitive job demands and negatively related to volume job demands. External task demands had an additional indirect effect on perceived patient consultation performance, as it was associated with lower levels of job satisfaction and higher levels of burnout. Implications/Conclusions Allowing community pharmacists to concentrate on tasks and limiting interruptions while performing these tasks are important factors in improving quality of patient care and pharmacist work life. The results have implications for strategies to improve patient safety and pharmacist performance. PMID:23791360

Attentional Capture of Objects Referred to by Spoken Language

ERIC Educational Resources Information Center

Salverda, Anne Pier; Altmann, Gerry T. M.

2011-01-01

Participants saw a small number of objects in a visual display and performed a visual detection or visual-discrimination task in the context of task-irrelevant spoken distractors. In each experiment, a visual cue was presented 400 ms after the onset of a spoken word. In experiments 1 and 2, the cue was an isoluminant color change and participants…

Optometric Measurements Predict Performance but not Comfort on a Virtual Object Placement Task with a Stereoscopic 3D Display

DTIC Science & Technology

2014-09-16

the display, matching the depth and vertical positioning of an identical reference or “target” object. This task served as a replication-and... cinema and computer games: A review.” Ophthalmic and Physiological Optics, 31, pp. 111-122. Hsu, J., Pizlo, Z., Chelberg, D. M., Babbs, C. F., and Delp

Augmented Reality versus Virtual Reality for 3D Object Manipulation.

PubMed

Krichenbauer, Max; Yamamoto, Goshiro; Taketom, Takafumi; Sandor, Christian; Kato, Hirokazu

2018-02-01

Virtual Reality (VR) Head-Mounted Displays (HMDs) are on the verge of becoming commodity hardware available to the average user and feasible to use as a tool for 3D work. Some HMDs include front-facing cameras, enabling Augmented Reality (AR) functionality. Apart from avoiding collisions with the environment, interaction with virtual objects may also be affected by seeing the real environment. However, whether these effects are positive or negative has not yet been studied extensively. For most tasks it is unknown whether AR has any advantage over VR. In this work we present the results of a user study in which we compared user performance measured in task completion time on a 9 degrees of freedom object selection and transformation task performed either in AR or VR, both with a 3D input device and a mouse. Our results show faster task completion time in AR over VR. When using a 3D input device, a purely VR environment increased task completion time by 22.5 percent on average compared to AR ( ). Surprisingly, a similar effect occurred when using a mouse: users were about 17.3 percent slower in VR than in AR ( ). Mouse and 3D input device produced similar task completion times in each condition (AR or VR) respectively. We further found no differences in reported comfort.

Heimdall System for MSSS Sensor Tasking

NASA Astrophysics Data System (ADS)

Herz, A.; Jones, B.; Herz, E.; George, D.; Axelrad, P.; Gehly, S.

In Norse Mythology, Heimdall uses his foreknowledge and keen eyesight to keep watch for disaster from his home near the Rainbow Bridge. Orbit Logic and the Colorado Center for Astrodynamics Research (CCAR) at the University of Colorado (CU) have developed the Heimdall System to schedule observations of known and uncharacterized objects and search for new objects from the Maui Space Surveillance Site. Heimdall addresses the current need for automated and optimized SSA sensor tasking driven by factors associated with improved space object catalog maintenance. Orbit Logic and CU developed an initial baseline prototype SSA sensor tasking capability for select sensors at the Maui Space Surveillance Site (MSSS) using STK and STK Scheduler, and then added a new Track Prioritization Component for FiSST-inspired computations for predicted Information Gain and Probability of Detection, and a new SSA-specific Figure-of-Merit (FOM) for optimized SSA sensor tasking. While the baseline prototype addresses automation and some of the multi-sensor tasking optimization, the SSA-improved prototype addresses all of the key elements required for improved tasking leading to enhanced object catalog maintenance. The Heimdall proof-of-concept was demonstrated for MSSS SSA sensor tasking for a 24 hour period to attempt observations of all operational satellites in the unclassified NORAD catalog, observe a small set of high priority GEO targets every 30 minutes, make a sky survey of the GEO belt region accessible to MSSS sensors, and observe particular GEO regions that have a high probability of finding new objects with any excess sensor time. This Heimdall prototype software paves the way for further R&D that will integrate this technology into the MSSS systems for operational scheduling, improve the software's scalability, and further tune and enhance schedule optimization. The Heimdall software for SSA sensor tasking provides greatly improved performance over manual tasking, improved coordinated sensor usage, and tasking schedules driven by catalog improvement goals (reduced overall covariance, etc.). The improved performance also enables more responsive sensor tasking to address external events, newly detected objects, newly detected object activity, and sensor anomalies. Instead of having to wait until the next day's scheduling phase, events can be addressed with new tasking schedules immediately (within seconds or minutes). Perhaps the most important benefit is improved SSA based on an overall improvement to the quality of the space catalog. By driving sensor tasking and scheduling based on predicted Information Gain and other relevant factors, better decisions are made in the application of available sensor resources, leading to an improved catalog and better information about the objects of most interest. The Heimdall software solution provides a configurable, automated system to improve sensor tasking efficiency and responsiveness for SSA applications. The FISST algorithms for Track Prioritization, SSA specific task and resource attributes, Scheduler algorithms, and configurable SSA-specific Figure-of-Merit together provide optimized and tunable scheduling for the Maui Space Surveillance Site and possibly other sites and organizations across the U.S. military and for allies around the world.

Dissociations and Associations of Performance in Syntactic Comprehension in Aphasia and their Implications for the Nature of Aphasic Deficits

PubMed Central

Caplan, David; Michaud, Jennifer; Hufford, Rebecca

2013-01-01

Sixty one pwa were tested on syntactic comprehension in three tasks: sentence-picture matching, sentence-picture matching with auditory moving window presentation, and object manipulation. There were significant correlations of performances on sentences across tasks. First factors in unrotated factor analyses accounted for most of the variance on which all sentence types loaded in each task. Dissociations in performance between sentence types that differed minimally in their syntactic structures were not consistent across tasks. These results replicate previous results with smaller samples and provide important validation of basic aspects of aphasic performance in this area of language processing. They point to the role of a reduction in processing resources and of the interaction of task demands and parsing and interpretive abilities in the genesis of patient performance. PMID:24061104

Lack of reliability in the disruption of cognitive performance following exposure to protons

USDA-ARS?s Scientific Manuscript database

A series of three replications were run to determine the reliability with which exposure to protons produces a disruption of cognitive performance, using a novel object recognition task and operant responding on an ascending fixed-ratio task. For the first two replications, rats were exposed to hea...

V-TECS Guide for Auto Mechanics: Suspension Systems, Brakes and Steering.

ERIC Educational Resources Information Center

Moore, Charles G.; And Others

The materials in this document are an extension of a catalog of occupational duties, tasks, and performance objectives relevant to maintaining automotive suspension systems, brakes, and steering mechanisms. This document provides the following for each occupational task within each duty: (1) a standard of performance; (2) the conditions under…

Representational momentum in perception and grasping: translating versus transforming objects.

PubMed

Brouwer, Anne-Marie; Franz, Volker H; Thornton, Ian M

2004-07-14

Representational momentum is the tendency to misremember the stopping point of a moving object as further forward in the direction of movement. Results of several studies suggest that this effect is typical for changes in position (e.g., translation) and not for changes in object shape (transformation). Additionally, the effect seems to be stronger in motor tasks than in perceptual tasks. Here, participants judged the final distance between two spheres after this distance had been increasing or decreasing. The spheres were two separately translating objects or were connected to form a single transforming object (a dumbbell). Participants also performed a motor task in which they grasped virtual versions of the final objects. We found representational momentum for the visual judgment task for both stimulus types. As predicted, it was stronger for the spheres than for the dumbbells. In contrast, for grasping, only the dumbbells produced representational momentum (larger maximum grip aperture when the dumbbells had been growing compared to when they had been shrinking). Because type of stimulus change had these different effects on representational momentum for perception and action, we conclude that different sources of information are used in the two tasks or that they are governed by different mechanisms.

Reach on sound: a key to object permanence in visually impaired children.

PubMed

Fazzi, Elisa; Signorini, Sabrina Giovanna; Bomba, Monica; Luparia, Antonella; Lanners, Josée; Balottin, Umberto

2011-04-01

The capacity to reach an object presented through sound clue indicates, in the blind child, the acquisition of object permanence and gives information over his/her cognitive development. To assess cognitive development in congenitally blind children with or without multiple disabilities. Cohort study. Thirty-seven congenitally blind subjects (17 with associated multiple disabilities, 20 mainly blind) were enrolled. We used Bigelow's protocol to evaluate "reach on sound" capacity over time (at 6, 12, 18, 24, and 36 months), and a battery of clinical, neurophysiological and cognitive instruments to assess clinical features. Tasks n.1 to 5 were acquired by most of the mainly blind children by 12 months of age. Task 6 coincided with a drop in performance, and the acquisition of the subsequent tasks showed a less agehomogeneous pattern. In blind children with multiple disabilities, task acquisition rates were lower, with the curves dipping in relation to the more complex tasks. The mainly blind subjects managed to overcome Fraiberg's "conceptual problem"--i.e., they acquired the ability to attribute an external object with identity and substance even when it manifested its presence through sound only--and thus developed the ability to reach an object presented through sound. Instead, most of the blind children with multiple disabilities presented poor performances on the "reach on sound" protocol and were unable, before 36 months of age, to develop the strategies needed to resolve Fraiberg's "conceptual problem". Copyright © 2011 Elsevier Ltd. All rights reserved.

Prefrontal Engagement during Source Memory Retrieval Depends on the Prior Encoding Task

PubMed Central

Kuo, Trudy Y.; Van Petten, Cyma

2008-01-01

The prefrontal cortex is strongly engaged by some, but not all, episodic memory tests. Prior work has shown that source recognition tests—those that require memory for conjunctions of studied attributes—yield deficient performance in patients with prefrontal damage and greater prefrontal activity in healthy subjects, as compared to simple recognition tests. Here, we tested the hypothesis that there is no intrinsic relationship between the prefrontal cortex and source memory, but that the prefrontal cortex is engaged by the demand to retrieve weakly encoded relationships. Subjects attempted to remember object/color conjunctions after an encoding task that focused on object identity alone, and an integrative encoding task that encouraged attention to object/color relationships. After the integrative encoding task, the late prefrontal brain electrical activity that typically occurs in source memory tests was eliminated. Earlier brain electrical activity related to successful recognition of the objects was unaffected by the nature of prior encoding. PMID:16839287

Dissociable performance on scene learning and strategy implementation after lesions to magnocellular mediodorsal thalamic nucleus

PubMed Central

Mitchell, Anna S.; Baxter, Mark G.; Gaffan, David

2008-01-01

Monkeys with aspiration lesions of the magnocellular division of the mediodorsal thalamus (MDmc) are impaired in object-in-place scene learning, object recognition and stimulus-reward association. These data have been interpreted to mean that projections from MDmc to prefrontal cortex are required to sustain normal prefrontal function in a variety of task settings. In the present study, we investigated the extent to which bilateral neurotoxic lesions of the MDmc impair a pre-operatively learnt strategy implementation task that is impaired by a crossed lesion technique that disconnects the frontal cortex in one hemisphere from the contralateral inferotemporal cortex. Postoperative memory impairments were also examined using the object-in-place scene memory task. Monkeys learnt both strategy implementation and scene memory tasks separately to a stable level pre-operatively. Bilateral neurotoxic lesions of the MDmc, produced by 10 × 1 μl injections of a mixture of ibotenate and N-methyl-D-aspartate did not affect performance in the strategy implementation task. However, new learning of object-in-place scene memory was substantially impaired. These results provide new evidence about the role of the magnocellular mediodorsal thalamic nucleus in memory processing, indicating that interconnections with the prefrontal cortex are essential during new learning but are not required when implementing a preoperatively acquired strategy task. Thus not all functions of the prefrontal cortex require MDmc input. Instead the involvement of MDmc in prefrontal function may be limited to situations in which new learning must occur. PMID:17978029

Semantic memory in object use.

PubMed

Silveri, Maria Caterina; Ciccarelli, Nicoletta

2009-10-01

We studied five patients with semantic memory disorders, four with semantic dementia and one with herpes simplex virus encephalitis, to investigate the involvement of semantic conceptual knowledge in object use. Comparisons between patients who had semantic deficits of different severity, as well as the follow-up, showed that the ability to use objects was largely preserved when the deficit was mild but progressively decayed as the deficit became more severe. Naming was generally more impaired than object use. Production tasks (pantomime execution and actual object use) and comprehension tasks (pantomime recognition and action recognition) as well as functional knowledge about objects were impaired when the semantic deficit was severe. Semantic and unrelated errors were produced during object use, but actions were always fluent and patients performed normally on a novel tools task in which the semantic demand was minimal. Patients with severe semantic deficits scored borderline on ideational apraxia tasks. Our data indicate that functional semantic knowledge is crucial for using objects in a conventional way and suggest that non-semantic factors, mainly non-declarative components of memory, might compensate to some extent for semantic disorders and guarantee some residual ability to use very common objects independently of semantic knowledge.

Changes of EEG Spectra and Functional Connectivity during an Object-Location Memory Task in Alzheimer's Disease.

PubMed

Han, Yuliang; Wang, Kai; Jia, Jianjun; Wu, Weiping

2017-01-01

Object-location memory is particularly fragile and specifically impaired in Alzheimer's disease (AD) patients. Electroencephalogram (EEG) was utilized to objectively measure memory impairment for memory formation correlates of EEG oscillatory activities. We aimed to construct an object-location memory paradigm and explore EEG signs of it. Two groups of 20 probable mild AD patients and 19 healthy older adults were included in a cross-sectional analysis. All subjects took an object-location memory task. EEG recordings performed during object-location memory tasks were compared between the two groups in the two EEG parameters (spectral parameters and phase synchronization). The memory performance of AD patients was worse than that of healthy elderly adults The power of object-location memory of the AD group was significantly higher than the NC group (healthy elderly adults) in the alpha band in the encoding session, and alpha and theta bands in the retrieval session. The channels-pairs the phase lag index value of object-location memory in the AD group was clearly higher than the NC group in the delta, theta, and alpha bands in encoding sessions and delta and theta bands in retrieval sessions. The results provide support for the hypothesis that the AD patients may use compensation mechanisms to remember the items and episode.

Ventral and Dorsal Visual Stream Contributions to the Perception of Object Shape and Object Location

PubMed Central

Zachariou, Valentinos; Klatzky, Roberta; Behrmann, Marlene

2017-01-01

Growing evidence suggests that the functional specialization of the two cortical visual pathways may not be as distinct as originally proposed. Here, we explore possible contributions of the dorsal “where/how” visual stream to shape perception and, conversely, contributions of the ventral “what” visual stream to location perception in human adults. Participants performed a shape detection task and a location detection task while undergoing fMRI. For shape detection, comparable BOLD activation in the ventral and dorsal visual streams was observed, and the magnitude of this activation was correlated with behavioral performance. For location detection, cortical activation was significantly stronger in the dorsal than ventral visual pathway and did not correlate with the behavioral outcome. This asymmetry in cortical profile across tasks is particularly noteworthy given that the visual input was identical and that the tasks were matched for difficulty in performance. We confirmed the asymmetry in a subsequent psychophysical experiment in which participants detected changes in either object location or shape, while ignoring the other, task-irrelevant dimension. Detection of a location change was slowed by an irrelevant shape change matched for difficulty, but the reverse did not hold. We conclude that both ventral and dorsal visual streams contribute to shape perception, but that location processing appears to be essentially a function of the dorsal visual pathway. PMID:24001005

Development of Internet-Based Tasks for the Executive Function Performance Test.

PubMed

Rand, Debbie; Lee Ben-Haim, Keren; Malka, Rachel; Portnoy, Sigal

The Executive Function Performance Test (EFPT) is a reliable and valid performance-based tool to assess executive functions (EFs). This study's objective was to develop and verify two Internet-based tasks for the EFPT. A cross-sectional study assessed the alternate-form reliability of the Internet-based bill-paying and telephone-use tasks in healthy adults and people with subacute stroke (Study 1). It also sought to establish the tasks' criterion reliability for assessing EF deficits by correlating performance with that on the Trail Making Test in five groups: healthy young adults, healthy older adults, people with subacute stroke, people with chronic stroke, and young adults with attention deficit hyperactivity disorder (Study 2). The alternative-form reliability and initial construct validity for the Internet-based bill-paying task were verified. Criterion validity was established for both tasks. The Internet-based tasks are comparable to the original EFPT tasks and can be used for assessment of EF deficits. Copyright © 2018 by the American Occupational Therapy Association, Inc.

Virtual reality computer simulation.

PubMed

Grantcharov, T P; Rosenberg, J; Pahle, E; Funch-Jensen, P

2001-03-01

Objective assessment of psychomotor skills should be an essential component of a modern surgical training program. There are computer systems that can be used for this purpose, but their wide application is not yet generally accepted. The aim of this study was to validate the role of virtual reality computer simulation as a method for evaluating surgical laparoscopic skills. The study included 14 surgical residents. On day 1, they performed two runs of all six tasks on the Minimally Invasive Surgical Trainer, Virtual Reality (MIST VR). On day 2, they performed a laparoscopic cholecystectomy on living pigs; afterward, they were tested again on the MIST VR. A group of experienced surgeons evaluated the trainees' performance on the animal operation, giving scores for total performance error and economy of motion. During the tasks on the MIST VR, errors and noneconomy of movements for the left and right hand were also recorded. There were significant correlations between error scores in vivo and three of the six in vitro tasks (p < 0.05). In vivo economy scores correlated significantly with non-economy right-hand scores for five of the six tasks and with non-economy left-hand scores for one of the six tasks (p < 0.05). In this study, laparoscopic performance in the animal model correlated significantly with performance on the computer simulator. Thus, the computer model seems to be a promising objective method for the assessment of laparoscopic psychomotor skills.

Locomotor Status and the Development of Spatial Search Skills.

ERIC Educational Resources Information Center

Bai, Dina L.; Bertenthal, Bennett I.

1992-01-01

Investigated the possibility that previous reports of a relation between locomotor status and stage-4 object permanence performance could be generalized to performance on an object localization task. Findings suggest that the effects of locomotor experience on infants' search performance are quite specific and mediated by a variety of factors that…

[Estimates of the size of inhibitory areas in crowding effects in periphery].

PubMed

Bondarko, V M; Danilova, M V; Solnushkin, S D; Chikhman, V N

2014-01-01

In psychophysical experiments we studied how surround influences recognition of test objects. The tests were low-contrast Landolt rings of the size 1.1, 1.5 and 2.3 deg. Their centers were located at 13.2 deg from the fixation point. The additional objects were similar Landolt rings or rings without gaps. The distance between the centers of the test and the additional objects varied from 2.2 to 13.2 deg. Inone experiment, the task of the observer was to identify both the test objects and the surrounding objects. In the second experiment the stimulus layout was the same, but'identification of only the test stimulus was required. In both experiments, deterioration of performance was found at all distances between the test objects and the surround, but the deterioration was more significant when the observer carried out the dual task. The data showed that the size of the inhibitory areas in our case does not comply with the Bouma low which states that the size of the interaction areas are equal to half of the eccentricity where the test is presented. Further deterioration of performance in the dual task reveals the contribution of attention into peripheral crowding effects.

Allocation of Attentional Resources toward a Secondary Cognitive Task Leads to Compromised Ankle Proprioceptive Performance in Healthy Young Adults

PubMed Central

Yasuda, Kazuhiro; Iimura, Naoyuki; Iwata, Hiroyasu

2014-01-01

The objective of the present study was to determine whether increased attentional demands influence the assessment of ankle joint proprioceptive ability in young adults. We used a dual-task condition, in which participants performed an ankle ipsilateral position-matching task with and without a secondary serial auditory subtraction task during target angle encoding. Two experiments were performed with two different cohorts: one in which the auditory subtraction task was easy (experiment 1a) and one in which it was difficult (experiment 1b). The results showed that, compared with the single-task condition, participants had higher absolute error under dual-task conditions in experiment 1b. The reduction in position-matching accuracy with an attentionally demanding cognitive task suggests that allocation of attentional resources toward a difficult second task can lead to compromised ankle proprioceptive performance. Therefore, these findings indicate that the difficulty level of the cognitive task might be the possible critical factor that decreased accuracy of position-matching task. We conclude that increased attentional demand with difficult cognitive task does influence the assessment of ankle joint proprioceptive ability in young adults when measured using an ankle ipsilateral position-matching task. PMID:24523966

Mechanisms underlying selecting objects for action

PubMed Central

Wulff, Melanie; Laverick, Rosanna; Humphreys, Glyn W.; Wing, Alan M.; Rotshtein, Pia

2015-01-01

We assessed the factors which affect the selection of objects for action, focusing on the role of action knowledge and its modulation by distracters. Fourteen neuropsychological patients and 10 healthy aged-matched controls selected pairs of objects commonly used together among distracters in two contexts: with real objects and with pictures of the same objects presented sequentially on a computer screen. Across both tasks, semantically related distracters led to slower responses and more errors than unrelated distracters and the object actively used for action was selected prior to the object that would be passively held during the action. We identified a sub-group of patients (N = 6) whose accuracy was 2SDs below the controls performances in the real object task. Interestingly, these impaired patients were more affected by the presence of unrelated distracters during both tasks than intact patients and healthy controls. Note that the impaired patients had lesions to left parietal, right anterior temporal and bilateral pre-motor regions. We conclude that: (1) motor procedures guide object selection for action, (2) semantic knowledge affects action-based selection, (3) impaired action decision making is associated with the inability to ignore distracting information and (4) lesions to either the dorsal or ventral visual stream can lead to deficits in making action decisions. Overall, the data indicate that impairments in everyday tasks can be evaluated using a simulated computer task. The implications for rehabilitation are discussed. PMID:25954177

Enhancing Cognition with Video Games: A Multiple Game Training Study

PubMed Central

Oei, Adam C.; Patterson, Michael D.

2013-01-01

Background Previous evidence points to a causal link between playing action video games and enhanced cognition and perception. However, benefits of playing other video games are under-investigated. We examined whether playing non-action games also improves cognition. Hence, we compared transfer effects of an action and other non-action types that required different cognitive demands. Methodology/Principal Findings We instructed 5 groups of non-gamer participants to play one game each on a mobile device (iPhone/iPod Touch) for one hour a day/five days a week over four weeks (20 hours). Games included action, spatial memory, match-3, hidden- object, and an agent-based life simulation. Participants performed four behavioral tasks before and after video game training to assess for transfer effects. Tasks included an attentional blink task, a spatial memory and visual search dual task, a visual filter memory task to assess for multiple object tracking and cognitive control, as well as a complex verbal span task. Action game playing eliminated attentional blink and improved cognitive control and multiple-object tracking. Match-3, spatial memory and hidden object games improved visual search performance while the latter two also improved spatial working memory. Complex verbal span improved after match-3 and action game training. Conclusion/Significance Cognitive improvements were not limited to action game training alone and different games enhanced different aspects of cognition. We conclude that training specific cognitive abilities frequently in a video game improves performance in tasks that share common underlying demands. Overall, these results suggest that many video game-related cognitive improvements may not be due to training of general broad cognitive systems such as executive attentional control, but instead due to frequent utilization of specific cognitive processes during game play. Thus, many video game training related improvements to cognition may be attributed to near-transfer effects. PMID:23516504

Age-related changes in frequency of mind-wandering and task-related interferences during memory encoding and their impact on retrieval.

PubMed

Maillet, David; Rajah, M Natasha

2013-01-01

During the performance of cognitive tasks such as memory encoding, attention can become decoupled from the external environment and instead focused on internal thoughts related to the appraisal of the current task (task-related interferences; TRI), or personal thoughts unrelated to the task at hand (mind-wandering; MW). However, the association between the frequency of these thoughts experienced at encoding and retrieval accuracy in young and older adults remains poorly understood. In this study young and older adults encoded lists of words using one of two encoding tasks: judging whether words are man-made/natural (objective task), or whether they are pleasant/neutral (subjective task). We measured the frequency of TRI and MW at encoding, and related them to retrieval accuracy in both age groups. We found that encoding task influenced the type of internal thoughts experienced by young, but not older, adults: young exhibited greater MW in the subjective vs the objective task, and greater TRI in the objective vs subjective encoding task. Second, across both tasks we found marked age-related decreases in both MW and TRI at encoding, and frequency of these thoughts negatively impacted memory retrieval in young adults only. We discuss these findings in relation to current theories of ageing, attention and memory.

Extrapyramidal signs in normal pressure hydrocephalus: an objective assessment

PubMed Central

Mandir, Allen S; Hilfiker, Jennifer; Thomas, George; Minahan, Robert E; Crawford, Thomas O; Williams, Michael A; Rigamonti, Daniele

2007-01-01

Background Beyond the classic Normal Pressure Hydrocephalus (NPH) triad of gait disturbance, incontinence, and dementia are characteristic signs of motor dysfunction in NPH patients. We used highly sensitive and objective methods to characterize upper limb extrapyramidal signs in a series of NPH subjects compared with controls. Concentrated evaluation of these profound, yet underappreciated movement disorders of NPH before and after techniques of therapeutic intervention may lead to improved diagnosis, insight into pathophysiology, and targeted treatment. Methods Twenty-two (22) consecutive NPH patients and 17 controls performed an upper limb motor task battery where highly sensitive and objective measures of akinesia/bradykinesia, tone, and tremor were conducted. NPH subjects performed this test battery before and more than 36 h after continuous CSF drainage via a spinal catheter over 72 h and, in those subjects undergoing permanent ventriculo-peritoneal shunt placement, at least 12 weeks later. Control subjects performed the task battery at the same dates as the NPH subjects. Statistical analyses were applied to group populations of NPH and control subjects and repeated measures for within subject performance. Results Twenty (20) NPH subjects remained in the study following CSF drainage as did 14 controls. NPH subjects demonstrated akinesia/bradykinesia (prolonged reaction and movement times) and increased resting tone compared with controls. Furthermore, the NPH group demonstrated increased difficulty with self-initiated tasks compared with stimulus-initiated tasks. Following CSF drainage, some NPH subjects demonstrated reduced movement times with greater improvement in self- versus stimulus-initiated tasks. Group reaction time was unchanged. Resting tremor present in one NPH subject resolved following shunt placement. Tone measures were consistent for all subjects throughout the study. Conclusion Clinical motor signs of NPH subjects extend beyond gait deficits and include extrapyramidal manifestations of bradykinesia, akinesia, rigidity, and propensity to perform more poorly when external cues to move are absent. Objective improvement of some but not all of these features was seen following temporary or permanent CSF diversion. PMID:17697324

Area Reports. Advanced materials and devices research area. Silicon materials research task, and advanced silicon sheet task

NASA Technical Reports Server (NTRS)

1986-01-01

The objectives of the Silicon Materials Task and the Advanced Silicon Sheet Task are to identify the critical technical barriers to low-cost silicon purification and sheet growth that must be overcome to produce a PV cell substrate material at a price consistent with Flat-plate Solar Array (FSA) Project objectives and to overcome these barriers by performing and supporting appropriate R&D. Progress reports are given on silicon refinement using silane, a chemical vapor transport process for purifying metallurgical grade silicon, silicon particle growth research, and modeling of silane pyrolysis in fluidized-bed reactors.

Human listening studies reveal insights into object features extracted by echolocating dolphins

NASA Astrophysics Data System (ADS)

Delong, Caroline M.; Au, Whitlow W. L.; Roitblat, Herbert L.

2004-05-01

Echolocating dolphins extract object feature information from the acoustic parameters of object echoes. However, little is known about which object features are salient to dolphins or how they extract those features. To gain insight into how dolphins might be extracting feature information, human listeners were presented with echoes from objects used in a dolphin echoic-visual cross-modal matching task. Human participants performed a task similar to the one the dolphin had performed; however, echoic samples consisting of 23-echo trains were presented via headphones. The participants listened to the echoic sample and then visually selected the correct object from among three alternatives. The participants performed as well as or better than the dolphin (M=88.0% correct), and reported using a combination of acoustic cues to extract object features (e.g., loudness, pitch, timbre). Participants frequently reported using the pattern of aural changes in the echoes across the echo train to identify the shape and structure of the objects (e.g., peaks in loudness or pitch). It is likely that dolphins also attend to the pattern of changes across echoes as objects are echolocated from different angles.

Quantifying kinematics of purposeful movements to real, imagined, or absent functional objects: implications for modelling trajectories for robot-assisted ADL tasks.

PubMed

Wisneski, Kimberly J; Johnson, Michelle J

2007-03-23

Robotic therapy is at the forefront of stroke rehabilitation. The Activities of Daily Living Exercise Robot (ADLER) was developed to improve carryover of gains after training by combining the benefits of Activities of Daily Living (ADL) training (motivation and functional task practice with real objects), with the benefits of robot mediated therapy (repeatability and reliability). In combining these two therapy techniques, we seek to develop a new model for trajectory generation that will support functional movements to real objects during robot training. We studied natural movements to real objects and report on how initial reaching movements are affected by real objects and how these movements deviate from the straight line paths predicted by the minimum jerk model, typically used to generate trajectories in robot training environments. We highlight key issues that to be considered in modelling natural trajectories. Movement data was collected as eight normal subjects completed ADLs such as drinking and eating. Three conditions were considered: object absent, imagined, and present. This data was compared to predicted trajectories generated from implementing the minimum jerk model. The deviations in both the plane of the table (XY) and the sagittal plane of torso (XZ) were examined for both reaches to a cup and to a spoon. Velocity profiles and curvature were also quantified for all trajectories. We hypothesized that movements performed with functional task constraints and objects would deviate from the minimum jerk trajectory model more than those performed under imaginary or object absent conditions. Trajectory deviations from the predicted minimum jerk model for these reaches were shown to depend on three variables: object presence, object orientation, and plane of movement. When subjects completed the cup reach their movements were more curved than for the spoon reach. The object present condition for the cup reach showed more curvature than in the object imagined and absent conditions. Curvature in the XZ plane of movement was greater than curvature in the XY plane for all movements. The implemented minimum jerk trajectory model was not adequate for generating functional trajectories for these ADLs. The deviations caused by object affordance and functional task constraints must be accounted for in order to allow subjects to perform functional task training in robotic therapy environments. The major differences that we have highlighted include trajectory dependence on: object presence, object orientation, and the plane of movement. With the ability to practice ADLs on the ADLER environment we hope to provide patients with a therapy paradigm that will produce optimal results and recovery.

Maternal Docosahexaenoic Acid Intake Levels during Pregnancy and Infant Performance on a Novel Object Search Task at 22 Months

ERIC Educational Resources Information Center

Rees, Alison; Sirois, Sylvain; Wearden, Alison

2014-01-01

This study investigated maternal prenatal docosahexaenoic acid (DHA) intake and infant cognitive development at 22 months. Estimates for second- and third-trimester maternal DHA intake levels were obtained using a comprehensive Food Frequency Questionnaire. Infants (n = 67) were assessed at 22 months on a novel object search task. Mothers'…

The Female Advantage in Object Location Memory is Robust to Verbalizability and Mode of Presentation of Test Stimuli

ERIC Educational Resources Information Center

Lejbak, Lisa; Vrbancic, Mirna; Crossley, Margaret

2009-01-01

This study extends Duff and Hampson's [Duff, S., & Hampson, E. (2001). A sex difference on a novel spatial working memory task in humans. "Brain and Cognition, 47," 470-493] finding of a sex-related difference in favor of females for an object location memory task. Twenty female and 20 male undergraduate students performed both manual and…

Programming of left hand exploits task set but that of right hand depends on recent history.

PubMed

Tang, Rixin; Zhu, Hong

2017-07-01

There are many differences between the left hand and the right hand. But it is not clear if there is a difference in programming between left hand and right hand when the hands perform the same movement. In current study, we carried out two experiments to investigate whether the programming of two hands was equivalent or they exploited different strategies. In the first experiment, participants were required to use one hand to grasp an object with visual feedback or to point to the center of one object without visual feedback on alternate trials, or to grasp an object without visual feedback and to point the center of one object with visual feedback on alternating trials. They then performed the tasks with the other hand. The result was that previous pointing task affected current grasping when it was performed by the left hand, but not the right hand. In experiment 2, we studied if the programming of the left (or right) hand would be affected by the pointing task performed on the previous trial not only by the same hand, but also by the right (or left) hand. Participants pointed and grasped the objects alternately with two hands. The result was similar with Experiment 1, i.e., left-hand grasping was affected by right-hand pointing, whereas right-hand grasping was immune from the interference from left hand. Taken together, the results suggest that when open- and closed-loop trials are interleaved, motor programming of grasping with the right hand was affected by the nature of the online feedback on the previous trial only if it was a grasping trial, suggesting that the trial-to-trial transfer depends on sensorimotor memory and not on task set. In contrast, motor programming of grasping with the left hand can use information about the nature of the online feedback on the previous trial to specify the parameters of the movement, even when the type of movement that occurred was quite different (i.e., pointing) and was performed with the right hand. This suggests that trial-to-trial transfer with the left hand depends on some sort of carry-over of task set for dealing with the availability of visual feedback.

Long-term repetition priming and semantic interference in a lexical-semantic matching task: tapping the links between object names and colors

PubMed Central

Lloyd-Jones, Toby J.; Nakabayashi, Kazuyo

2014-01-01

Using a novel paradigm to engage the long-term mappings between object names and the prototypical colors for objects, we investigated the retrieval of object-color knowledge as indexed by long-term priming (the benefit in performance from a prior encounter with the same or a similar stimulus); a process about which little is known. We examined priming from object naming on a lexical-semantic matching task. In the matching task participants encountered a visually presented object name (Experiment 1) or object shape (Experiment 2) paired with either a color patch or color name. The pairings could either match whereby both were consistent with a familiar object (e.g., strawberry and red) or mismatch (strawberry and blue). We used the matching task to probe knowledge about familiar objects and their colors pre-activated during object naming. In particular, we examined whether the retrieval of object-color information was modality-specific and whether this influenced priming. Priming varied with the nature of the retrieval process: object-color priming arose for object names but not object shapes and beneficial effects of priming were observed for color patches whereas inhibitory priming arose with color names. These findings have implications for understanding how object knowledge is retrieved from memory and modified by learning. PMID:25009522

Relationships between Contextual and Task Performance and Interrater Agreement: Are There Any?

PubMed

Díaz-Vilela, Luis F; Delgado Rodríguez, Naira; Isla-Díaz, Rosa; Díaz-Cabrera, Dolores; Hernández-Fernaud, Estefanía; Rosales-Sánchez, Christian

2015-01-01

Work performance is one of the most important dependent variables in Work and Organizational Psychology. The main objective of this paper was to explore the relationships between citizenship performance and task performance measures obtained from different appraisers and their consistency through a seldom-used methodology, intraclass correlation coefficients. Participants were 135 public employees, the total staff in a local government department. Jobs were clustered into job families through a work analysis based on standard questionnaires. A task description technique was used to develop a performance appraisal questionnaire for each job family, with three versions: self-, supervisor-, and peer-evaluation, in addition to a measure of citizenship performance. Only when the self-appraisal bias is controlled, significant correlations appeared between task performance rates. However, intraclass correlations analyses show that only self- (contextual and task) performance measures are consistent, while interrater agreement disappears. These results provide some interesting clues about the procedure of appraisal instrument development, the role of appraisers, and the importance of choosing adequate consistency analysis methods.

Relationships between Contextual and Task Performance and Interrater Agreement: Are There Any?

PubMed Central

Díaz-Cabrera, Dolores; Hernández-Fernaud, Estefanía; Rosales-Sánchez, Christian

2015-01-01

Work performance is one of the most important dependent variables in Work and Organizational Psychology. The main objective of this paper was to explore the relationships between citizenship performance and task performance measures obtained from different appraisers and their consistency through a seldom-used methodology, intraclass correlation coefficients. Participants were 135 public employees, the total staff in a local government department. Jobs were clustered into job families through a work analysis based on standard questionnaires. A task description technique was used to develop a performance appraisal questionnaire for each job family, with three versions: self-, supervisor-, and peer-evaluation, in addition to a measure of citizenship performance. Only when the self-appraisal bias is controlled, significant correlations appeared between task performance rates. However, intraclass correlations analyses show that only self- (contextual and task) performance measures are consistent, while interrater agreement disappears. These results provide some interesting clues about the procedure of appraisal instrument development, the role of appraisers, and the importance of choosing adequate consistency analysis methods. PMID:26473956

EASE (Experimental Assembly of Structures in EVA) overview of selected results

NASA Technical Reports Server (NTRS)

Akin, David L.

1987-01-01

Experimental Assembly of Structures in EVA (EASE) objectives, experimental protocol, neutral buoyancy simulation, task time distribution, assembly task performance, metabolic rate/biomedical readouts are summarized. This presentation is shown in charts, figures, and graphs.

Cognitive Effects of Risperidone in Children with Autism and Irritable Behavior

PubMed Central

Aman, Michael G.; McDougle, Christopher J.; Scahill, Lawrence; Tierney, Elaine; McCracken, James T.; Arnold, L. Eugene; Vitiello, Benedetto; Ritz, Louise; Gavaletz, Allison; Cronin, Pegeen; Swiezy, Naomi; Wheeler, Courtney; Koenig, Kathleen; Ghuman, Jaswinder K.; Posey, David J.

2008-01-01

Abstract Objective The objective of this research was to explore the effects of risperidone on cognitive processes in children with autism and irritable behavior. Method Thirty-eight children, ages 5–17 years with autism and severe behavioral disturbance, were randomly assigned to risperidone (0.5 to 3.5 mg/day) or placebo for 8 weeks. This sample of 38 was a subset of 101 subjects who participated in the clinical trial; 63 were unable to perform the cognitive tasks. A double-blind placebo-controlled parallel groups design was used. Dependent measures included tests of sustained attention, verbal learning, hand-eye coordination, and spatial memory assessed before, during, and after the 8-week treatment. Changes in performance were compared by repeated measures ANOVA. Results Twenty-nine boys and 9 girls with autism and severe behavioral disturbance and a mental age ≥18 months completed the cognitive part of the study. No decline in performance occurred with risperidone. Performance on a cancellation task (number of correct detections) and a verbal learning task (word recognition) was better on risperidone than on placebo (without correction for multiplicity). Equivocal improvement also occurred on a spatial memory task. There were no significant differences between treatment conditions on the Purdue Pegboard (hand-eye coordination) task or the Analog Classroom Task (timed math test). Conclusion Risperidone given to children with autism at doses up to 3.5 mg for up to 8 weeks appears to have no detrimental effect on cognitive performance. PMID:18582177

Role of the parahippocampal cortex in memory for the configuration but not the identity of objects: converging evidence from patients with selective thermal lesions and fMRI

PubMed Central

Bohbot, Véronique D.; Allen, John J. B.; Dagher, Alain; Dumoulin, Serge O.; Evans, Alan C.; Petrides, Michael; Kalina, Miroslav; Stepankova, Katerina; Nadel, Lynn

2015-01-01

The parahippocampal cortex and hippocampus are brain structures known to be involved in memory. However, the unique contribution of the parahippocampal cortex remains unclear. The current study investigates memory for object identity and memory of the configuration of objects in patients with small thermo-coagulation lesions to the hippocampus or the parahippocampal cortex. Results showed that in contrast to control participants and patients with damage to the hippocampus leaving the parahippocampal cortex intact, patients with lesions that included the right parahippocampal cortex (RPH) were severely impaired on a task that required learning the spatial configuration of objects on a computer screen; these patients, however, were not impaired at learning the identity of objects. Conversely, we found that patients with lesions to the right hippocampus (RH) or left hippocampus (LH), sparing the parahippocampal cortex, performed just as well as the control participants. Furthermore, they were not impaired on the object identity task. In the functional Magnetic Resonance Imaging (fMRI) experiment, healthy young adults performed the same tasks. Consistent with the findings of the lesion study, the fMRI results showed significant activity in the RPH in the memory for the spatial configuration condition, but not memory for object identity. Furthermore, the pattern of fMRI activity measured in the baseline control conditions decreased specifically in the parahippocampal cortex as a result of the experimental task, providing evidence for task specific repetition suppression. In summary, while our previous studies demonstrated that the hippocampus is critical to the construction of a cognitive map, both the lesion and fMRI studies have shown an involvement of the RPH for learning spatial configurations of objects but not object identity, and that this takes place independent of the hippocampus. PMID:26283949

Feedforward object-vision models only tolerate small image variations compared to human

PubMed Central

Ghodrati, Masoud; Farzmahdi, Amirhossein; Rajaei, Karim; Ebrahimpour, Reza; Khaligh-Razavi, Seyed-Mahdi

2014-01-01

Invariant object recognition is a remarkable ability of primates' visual system that its underlying mechanism has constantly been under intense investigations. Computational modeling is a valuable tool toward understanding the processes involved in invariant object recognition. Although recent computational models have shown outstanding performances on challenging image databases, they fail to perform well in image categorization under more complex image variations. Studies have shown that making sparse representation of objects by extracting more informative visual features through a feedforward sweep can lead to higher recognition performances. Here, however, we show that when the complexity of image variations is high, even this approach results in poor performance compared to humans. To assess the performance of models and humans in invariant object recognition tasks, we built a parametrically controlled image database consisting of several object categories varied in different dimensions and levels, rendered from 3D planes. Comparing the performance of several object recognition models with human observers shows that only in low-level image variations the models perform similar to humans in categorization tasks. Furthermore, the results of our behavioral experiments demonstrate that, even under difficult experimental conditions (i.e., briefly presented masked stimuli with complex image variations), human observers performed outstandingly well, suggesting that the models are still far from resembling humans in invariant object recognition. Taken together, we suggest that learning sparse informative visual features, although desirable, is not a complete solution for future progresses in object-vision modeling. We show that this approach is not of significant help in solving the computational crux of object recognition (i.e., invariant object recognition) when the identity-preserving image variations become more complex. PMID:25100986

Detection of Operator Performance Breakdown as an Automation Triggering Mechanism

NASA Technical Reports Server (NTRS)

Yoo, Hyo-Sang; Lee, Paul U.; Landry, Steven J.

2015-01-01

Performance breakdown (PB) has been anecdotally described as a state where the human operator "loses control of context" and "cannot maintain required task performance." Preventing such a decline in performance is critical to assure the safety and reliability of human-integrated systems, and therefore PB could be useful as a point at which automation can be applied to support human performance. However, PB has never been scientifically defined or empirically demonstrated. Moreover, there is no validated objective way of detecting such a state or the transition to that state. The purpose of this work is: 1) to empirically demonstrate a PB state, and 2) to develop an objective way of detecting such a state. This paper defines PB and proposes an objective method for its detection. A human-in-the-loop study was conducted: 1) to demonstrate PB by increasing workload until the subject reported being in a state of PB, and 2) to identify possible parameters of a detection method for objectively identifying the subjectively-reported PB point, and 3) to determine if the parameters are idiosyncratic to an individual/context or are more generally applicable. In the experiment, fifteen participants were asked to manage three concurrent tasks (one primary and two secondary) for 18 minutes. The difficulty of the primary task was manipulated over time to induce PB while the difficulty of the secondary tasks remained static. The participants' task performance data was collected. Three hypotheses were constructed: 1) increasing workload will induce subjectively-identified PB, 2) there exists criteria that identifies the threshold parameters that best matches the subjectively-identified PB point, and 3) the criteria for choosing the threshold parameters is consistent across individuals. The results show that increasing workload can induce subjectively-identified PB, although it might not be generalizable-only 12 out of 15 participants declared PB. The PB detection method based on signal detection analysis was applied to the performance data and the results showed that PB can be identified using the method, particularly when the values of the parameters for the detection method were calibrated individually.

Modeling task-specific neuronal ensembles improves decoding of grasp

NASA Astrophysics Data System (ADS)

Smith, Ryan J.; Soares, Alcimar B.; Rouse, Adam G.; Schieber, Marc H.; Thakor, Nitish V.

2018-06-01

Objective. Dexterous movement involves the activation and coordination of networks of neuronal populations across multiple cortical regions. Attempts to model firing of individual neurons commonly treat the firing rate as directly modulating with motor behavior. However, motor behavior may additionally be associated with modulations in the activity and functional connectivity of neurons in a broader ensemble. Accounting for variations in neural ensemble connectivity may provide additional information about the behavior being performed. Approach. In this study, we examined neural ensemble activity in primary motor cortex (M1) and premotor cortex (PM) of two male rhesus monkeys during performance of a center-out reach, grasp and manipulate task. We constructed point process encoding models of neuronal firing that incorporated task-specific variations in the baseline firing rate as well as variations in functional connectivity with the neural ensemble. Models were evaluated both in terms of their encoding capabilities and their ability to properly classify the grasp being performed. Main results. Task-specific ensemble models correctly predicted the performed grasp with over 95% accuracy and were shown to outperform models of neuronal activity that assume only a variable baseline firing rate. Task-specific ensemble models exhibited superior decoding performance in 82% of units in both monkeys (p  <  0.01). Inclusion of ensemble activity also broadly improved the ability of models to describe observed spiking. Encoding performance of task-specific ensemble models, measured by spike timing predictability, improved upon baseline models in 62% of units. Significance. These results suggest that additional discriminative information about motor behavior found in the variations in functional connectivity of neuronal ensembles located in motor-related cortical regions is relevant to decode complex tasks such as grasping objects, and may serve the basis for more reliable and accurate neural prosthesis.

Repeated Δ9-tetrahydrocannabinol exposure in adolescent monkeys: persistent effects selective for spatial working memory.

PubMed

Verrico, Christopher D; Gu, Hong; Peterson, Melanie L; Sampson, Allan R; Lewis, David A

2014-04-01

Epidemiological findings suggest that, relative to adults, adolescents are more vulnerable to the adverse persistent effects of cannabis on working memory. However, the potential confounds inherent in human studies preclude direct determination of a cause-and-effect relationship between adolescent cannabis use and heightened susceptibility to persistent working memory impairments. Consequently, the authors examined the effects of repeated exposure to Δ9-tetrahydrocannabinol (THC) on performance of spatial and object working memory tasks in adolescent monkeys. Seven pairs of male adolescent rhesus monkeys, matched for baseline cognitive performance, received vehicle or THC intravenously 5 days/week for 6 months. Performance on spatial and object memory tasks was assessed 23 or 71 hours after drug administration throughout the study. In addition, acute effects on working memory were also assessed at the beginning and end of the 6-month period. Relative to the vehicle-exposed control animals, those with repeated THC exposure had a blunted trajectory of accuracy improvements on the spatial working memory task in a delay-dependent manner. Accuracy improvements on the object working memory task did not differ between groups. Relative to the acute effects of THC on working memory at the beginning of the study, neither sensitivity nor tolerance was evident after 6 months of THC exposure. Because maturation of performance is later for spatial than for object working memory, these findings suggest that persistent effects of THC on cognitive abilities are more evident when exposure coincides with the developmental stage during which the underlying neural circuits are actively maturing.

Dissociations and associations of performance in syntactic comprehension in aphasia and their implications for the nature of aphasic deficits.

PubMed

Caplan, David; Michaud, Jennifer; Hufford, Rebecca

2013-10-01

Sixty-one pwa were tested on syntactic comprehension in three tasks: sentence-picture matching, sentence-picture matching with auditory moving window presentation, and object manipulation. There were significant correlations of performances on sentences across tasks. First factors on which all sentence types loaded in unrotated factor analyses accounted for most of the variance in each task. Dissociations in performance between sentence types that differed minimally in their syntactic structures were not consistent across tasks. These results replicate previous results with smaller samples and provide important validation of basic aspects of aphasic performance in this area of language processing. They point to the role of a reduction in processing resources and of the interaction of task demands and parsing and interpretive abilities in the genesis of patient performance. Copyright © 2013 Elsevier Inc. All rights reserved.

Interindividual Differences in Learning Performance: The Effects of Age, Intelligence, and Strategic Task Approach

ERIC Educational Resources Information Center

Kliegel, Matthias; Altgassen, Mareike

2006-01-01

The present study investigated fluid and crystallized intelligence as well as strategic task approaches as potential sources of age-related differences in adult learning performance. Therefore, 45 young and 45 old adults were asked to learn pictured objects. Overall, young participants outperformed old participants in this learning test. However,…

Affective Factors Influencing Fluent Performance: French Learners' Appraisals of Second Language Speech Tasks

ERIC Educational Resources Information Center

Kormos, Judit; Préfontaine, Yvonne

2017-01-01

The present mixed-methods study examined the role of learner appraisals of speech tasks in second language (L2) French fluency. Forty adult learners in a Canadian immersion program participated in the study that compared four sources of data: (1) objectively measured utterance fluency in participants' performances of three narrative tasks…

A Comparative Analysis of Tasks Essential to Successful Performance in Three Veterinarian Lay Occupations. Summary Research 5.

ERIC Educational Resources Information Center

McCracken, J. David; Cooke, Frederick C.

The occupational survey's purpose was to identify the skills which are performed and essential for success in three veterinary lay occupations: animal health assistant, animal hospital receptionist, and animal health technician. Survey objectives were accomplished by constructing an initial task inventory of 21 duty areas, validating the initial…

Task-Oriented Gaming for Transfer to Prosthesis Use.

PubMed

van Dijk, Ludger; van der Sluis, Corry K; van Dijk, Hylke W; Bongers, Raoul M

2016-12-01

The aim of this study is to establish the effect of task-oriented video gaming on using a myoelectric prosthesis in a basic activity of daily life (ADL). Forty-one able-bodied right-handed participants were randomly assigned to one of four groups. In three of these groups the participants trained to control a video game using the myosignals of the flexors and extensors of the wrist: in the Adaptive Catching group participants needed to catch falling objects by opening and closing a grabber and received ADL-relevant feedback during performance. The Free Catching group used the same game, but without augmented feedback. The Interceptive Catching group trained a game where the goal was to intercept a falling object by moving a grabber to the left and right. They received no additional feedback. The control group played a regular Mario computer game. All groups trained 20 minutes a day for four consecutive days. Two tests were conducted before and after training: one level of the training game was performed, and participants grasped objects with a prosthesis simulator. Results showed all groups improved their game performance over controls. In the prosthesis-simulator task, after training the Adaptive Catching group outperformed the other groups in their ability to adjust the hand aperture to the size of the objects and the degree of compression of compressible objects. This study is the first to demonstrate transfer effects from a serious game to a myoelectric prosthesis task. The specificity of the learning effects suggests that research into serious gaming will benefit from placing ADL-specific constraints on game development.

Task and spatial frequency modulations of object processing: an EEG study.

PubMed

Craddock, Matt; Martinovic, Jasna; Müller, Matthias M

2013-01-01

Visual object processing may follow a coarse-to-fine sequence imposed by fast processing of low spatial frequencies (LSF) and slow processing of high spatial frequencies (HSF). Objects can be categorized at varying levels of specificity: the superordinate (e.g. animal), the basic (e.g. dog), or the subordinate (e.g. Border Collie). We tested whether superordinate and more specific categorization depend on different spatial frequency ranges, and whether any such dependencies might be revealed by or influence signals recorded using EEG. We used event-related potentials (ERPs) and time-frequency (TF) analysis to examine the time course of object processing while participants performed either a grammatical gender-classification task (which generally forces basic-level categorization) or a living/non-living judgement (superordinate categorization) on everyday, real-life objects. Objects were filtered to contain only HSF or LSF. We found a greater positivity and greater negativity for HSF than for LSF pictures in the P1 and N1 respectively, but no effects of task on either component. A later, fronto-central negativity (N350) was more negative in the gender-classification task than the superordinate categorization task, which may indicate that this component relates to semantic or syntactic processing. We found no significant effects of task or spatial frequency on evoked or total gamma band responses. Our results demonstrate early differences in processing of HSF and LSF content that were not modulated by categorization task, with later responses reflecting such higher-level cognitive factors.

Does Dysphoria Lead to Divergent Mental Fatigue Effects on a Cognitive Task?

PubMed

Hopstaken, Jesper F; Wanmaker, Sabine; van der Linden, Dimitri; Bakker, Arnold B

2015-01-01

Tiredness, low energy, and listlessness are common symptoms to be associated with depression. The question remains to what extent these symptoms influence the effects of fatigue on sustained performance tasks, such as impaired task engagement and performance. Based on earlier findings, it was hypothesized that dysphoric (i.e., mildly depressed) individuals, compared to healthy controls, would display earlier fatigue onset and more severe fatigue effects on task engagement and performance during a cognitive task. Sixty-one dysphoric and twenty-one non-dysphoric control participants were compared during one hour of continuous performance on a 2-back task. During the task subjective fatigue, subjective engagement, objective task performance, baseline pupil diameter and stimulus-evoked pupil dilation were measured. While we found that the dysphoric group reported relatively higher subjective fatigue than the healthy control group at the start of the experiment, we did not find any other divergent fatigue effects during the experimental task. One explanation for the absence of divergent effect is that dysphoria may not have such a profound impact on available cognitive resources, like attention, as initially thought. Based on the results of the present study, we conclude that dysphoria is not necessarily an increased risk factor for impaired sustained performance on cognitive tasks that may induce mental fatigue.

Subjective cognitive complaints and neuropsychological performance in former smokers with and without chronic obstructive pulmonary disease.

PubMed

Brunette, Amanda M; Holm, Kristen E; Wamboldt, Frederick S; Kozora, Elizabeth; Moser, David J; Make, Barry J; Crapo, James D; Meschede, Kimberly; Weinberger, Howard D; Moreau, Kerrie L; Bowler, Russell P; Hoth, Karin F

2018-05-01

This study examined the association of perceived cognitive difficulties with objective cognitive performance in former smokers. We hypothesized that greater perceived cognitive difficulties would be associated with poorer performance on objective executive and memory tasks. Participants were 95 former smokers recruited from the COPDGene study. They completed questionnaires (including the Cognitive Difficulties Scale [CDS] and the Hospital Anxiety and Depression Scale [HADS]), neuropsychological assessment, and pulmonary function testing. Pearson correlations and t-tests were conducted to examine the bivariate association of the CDS (total score and subscales for attention/concentration, praxis, delayed recall, orientation for persons, temporal orientation, and prospective memory) with each domain of objective cognitive functioning (memory recall, executive functioning/processing speed, visuospatial processing, and language). Simultaneous multiple linear regression was used to further examine all statistically significant bivariate associations. The following covariates were included in all regression models: age, sex, pack-years, premorbid functioning (WRAT-IV Reading), HADS total score, and chronic obstructive pulmonary disease (COPD) status (yes/no based on GOLD criteria). In regression models, greater perceived cognitive difficulties overall (using CDS total score) were associated with poorer performance on executive functioning/processing speed tasks (b = -0.07, SE = 0.03, p = .037). Greater perceived cognitive difficulties on the CDS praxis subscale were associated with poorer performance on executive functioning/processing speed tasks (b = -3.65, SE = 1.25, p = .005), memory recall tasks (b = -4.60, SE = 1.75, p = .010), and language tasks (b = -3.89, SE = 1.39, p = .006). Clinicians should be aware that cognitive complaints may be indicative of problems with the executive functioning/processing speed and memory of former smokers with and without COPD.

A visual processing advantage for young-adolescent deaf observers: Evidence from face and object matching tasks

PubMed Central

Megreya, Ahmed M.; Bindemann, Markus

2017-01-01

It is unresolved whether the permanent auditory deprivation that deaf people experience leads to the enhanced visual processing of faces. The current study explored this question with a matching task in which observers searched for a target face among a concurrent lineup of ten faces. This was compared with a control task in which the same stimuli were presented upside down, to disrupt typical face processing, and an object matching task. A sample of young-adolescent deaf observers performed with higher accuracy than hearing controls across all of these tasks. These results clarify previous findings and provide evidence for a general visual processing advantage in deaf observers rather than a face-specific effect. PMID:28117407

Sustained and transient attention in the continuous performance task.

PubMed

Smid, H G O M; de Witte, M R; Homminga, I; van den Bosch, R J

2006-08-01

One of the most frequently applied methods to study abnormal cognition is the Continuous Performance Task (CPT). It is unclear, however, which cognitive functions are engaged in normal CPT performance. The aims of the present study were to identify the neurocognitive functions engaged in the main variants of the CPT and to determine to what extent these variants differentially engage these functions. We hypothesized that the main CPT versions (CPT-X, CPT-AX, CPT-Identical Pairs) can be distinguished by whether they demand sustained or transient attention and sustained or transient response preparation. Transient attention to objects like letters or digits, that is, the need to switch attention to different objects from trial to trial, impairs target detection accuracy relative to sustained attention to a single object. Transient response preparation, that is, the possibility to switch response preparation on and off from trial to trial, improves response speed relative to having to sustain response preparation across all trials. Comparison of task performance and Event-Related brain Potentials (ERPs) of healthy participants obtained in the main CPT variants confirmed these hypotheses. Behavioral and ERP measures indicated worse target detection in the CPT-AX than in the CPT-X, consistent with a higher demand on transient attention in that task. In contrast, behavioral and ERP measures indicated higher response speed in the CPT-AX than in the CPT-X, associated with more response preparation in advance of the targets. This supports the idea of increased transient response preparation in the CPT-AX. We conclude that CPTs differ along at least two task variables that each influences a different cognitive function.

Functional coupling of sensorimotor and associative areas during a catching ball task: a qEEG coherence study

PubMed Central

2012-01-01

Background Catching an object is a complex movement that involves not only programming but also effective motor coordination. Such behavior is related to the activation and recruitment of cortical regions that participates in the sensorimotor integration process. This study aimed to elucidate the cortical mechanisms involved in anticipatory actions when performing a task of catching an object in free fall. Methods Quantitative electroencephalography (qEEG) was recorded using a 20-channel EEG system in 20 healthy right-handed participants performed the catching ball task. We used the EEG coherence analysis to investigate subdivisions of alpha (8-12 Hz) and beta (12-30 Hz) bands, which are related to cognitive processing and sensory-motor integration. Results Notwithstanding, we found the main effects for the factor block; for alpha-1, coherence decreased from the first to sixth block, and the opposite effect occurred for alpha-2 and beta-2, with coherence increasing along the blocks. Conclusion It was concluded that to perform successfully our task, which involved anticipatory processes (i.e. feedback mechanisms), subjects exhibited a great involvement of sensory-motor and associative areas, possibly due to organization of information to process visuospatial parameters and further catch the falling object. PMID:22364485

Object-directed imitation in autism spectrum disorder is differentially influenced by motoric task complexity, but not social contextual cues.

PubMed

Chetcuti, Lacey; Hudry, Kristelle; Grant, Megan; Vivanti, Giacomo

2017-11-01

We examined the role of social motivation and motor execution factors in object-directed imitation difficulties in autism spectrum disorder. A series of to-be-imitated actions was presented to 35 children with autism spectrum disorder and 20 typically developing children on an Apple ® iPad ® by a socially responsive or aloof model, under conditions of low and high motor demand. There were no differences in imitation performance (i.e. the number of actions reproduced within a fixed sequence), for either group, in response to a model who acted socially responsive or aloof. Children with autism spectrum disorder imitated the high motor demand task more poorly than the low motor demand task, while imitation performance for typically developing children was equivalent across the low and high motor demand conditions. Furthermore, imitative performance in the autism spectrum disorder group was unrelated to social reciprocity, though positively associated with fine motor coordination. These results suggest that difficulties in object-directed imitation in autism spectrum disorder are the result of motor execution difficulties, not reduced social motivation.

False belief understanding in Cantonese-speaking children.

PubMed

Tardif, Twila; Wellman, Henry M; Cheung, Kar Man

2004-11-01

The present study investigates the performance of 96 Cantonese-speaking three- to five-year-old preschoolers on three false belief tasks - a deceptive object, a change of location, and an unexpected contents task encompassing a variety of task factors. Most importantly, the research examines the possibility that false belief performance depends on specific linguistic factors such as the type of verb used in the test question--an explicitly false vs. a neutral belief verb. Cantonese was chosen as particularly useful for examining this question because it explicitly codes belief status as either neutral (nam5) or false (ji5wai4), and because it offers additional linguistic and cultural contrasts to research conducted on false belief with children learning English and other Indo-European languages. As expected, a strong age effect was found, as well as a significant advantage for children who received the explicit false belief (ji5wai4) wording and for those who were asked to explain rather than predict the protagonist's actions. Interestingly, there was also a strong task difference with children performing better on the deceptive object task than on the other two false belief tasks. We argue that these results point both to universal trajectories in theory of mind development and to interesting, but localized, effects of language and culture on children's false belief understanding.

Single-trial effective brain connectivity patterns enhance discriminability of mental imagery tasks

NASA Astrophysics Data System (ADS)

Rathee, Dheeraj; Cecotti, Hubert; Prasad, Girijesh

2017-10-01

Objective. The majority of the current approaches of connectivity based brain-computer interface (BCI) systems focus on distinguishing between different motor imagery (MI) tasks. Brain regions associated with MI are anatomically close to each other, hence these BCI systems suffer from low performances. Our objective is to introduce single-trial connectivity feature based BCI system for cognition imagery (CI) based tasks wherein the associated brain regions are located relatively far away as compared to those for MI. Approach. We implemented time-domain partial Granger causality (PGC) for the estimation of the connectivity features in a BCI setting. The proposed hypothesis has been verified with two publically available datasets involving MI and CI tasks. Main results. The results support the conclusion that connectivity based features can provide a better performance than a classical signal processing framework based on bandpass features coupled with spatial filtering for CI tasks, including word generation, subtraction, and spatial navigation. These results show for the first time that connectivity features can provide a reliable performance for imagery-based BCI system. Significance. We show that single-trial connectivity features for mixed imagery tasks (i.e. combination of CI and MI) can outperform the features obtained by current state-of-the-art method and hence can be successfully applied for BCI applications.

Surgeons' display reduced mental effort and workload while performing robotically assisted surgical tasks, when compared to conventional laparoscopy.

PubMed

Moore, Lee J; Wilson, Mark R; McGrath, John S; Waine, Elizabeth; Masters, Rich S W; Vine, Samuel J

2015-09-01

Research has demonstrated the benefits of robotic surgery for the patient; however, research examining the benefits of robotic technology for the surgeon is limited. This study aimed to adopt validated measures of workload, mental effort, and gaze control to assess the benefits of robotic surgery for the surgeon. We predicted that the performance of surgical training tasks on a surgical robot would require lower investments of workload and mental effort, and would be accompanied by superior gaze control and better performance, when compared to conventional laparoscopy. Thirty-two surgeons performed two trials on a ball pick-and-drop task and a rope-threading task on both robotic and laparoscopic systems. Measures of workload (the surgery task load index), mental effort (subjective: rating scale for mental effort and objective: standard deviation of beat-to-beat intervals), gaze control (using a mobile eye movement recorder), and task performance (completion time and number of errors) were recorded. As expected, surgeons performed both tasks more quickly and accurately (with fewer errors) on the robotic system. Self-reported measures of workload and mental effort were significantly lower on the robotic system compared to the laparoscopic system. Similarly, an objective cardiovascular measure of mental effort revealed lower investment of mental effort when using the robotic platform relative to the laparoscopic platform. Gaze control distinguished the robotic from the laparoscopic systems, but not in the predicted fashion, with the robotic system associated with poorer (more novice like) gaze control. The findings highlight the benefits of robotic technology for surgical operators. Specifically, they suggest that tasks can be performed more proficiently, at a lower workload, and with the investment of less mental effort, this may allow surgeons greater cognitive resources for dealing with other demands such as communication, decision-making, or periods of increased complexity in the operating room.

Tool use in left-brain-damaged patients: Difficulties in reasoning but not in estimating the physical properties of objects.

PubMed

Faye, Alexandrine; Jacquin-Courtois, Sophie; Osiurak, François

2018-03-01

The purpose of this study was to deepen our understanding of the cognitive bases of human tool use based on the technical reasoning hypothesis (i.e., the reasoning-based approach). This approach assumes that tool use is supported by the ability to reason about an object's physical properties (e.g., length, weight, strength, etc.) to perform mechanical actions (e.g., lever). In this framework, an important issue is to understand whether left-brain-damaged (LBD) individuals with tool-use deficits are still able to estimate the physical object's properties necessary to use the tool. Eleven LBD patients and 12 control participants performed 3 original experimental tasks: Use-Length (visual evaluation of the length of a stick to bring down a target), Visual-Length (to visually compare objects of different lengths) and Addition-Length (to visually compare added lengths). Participants were also tested on conventional tasks: Familiar Tool Use and Mechanical Problem-Solving (novel tools). LBD patients had more difficulties than controls on both conventional tasks. No significant differences were observed for the 3 experimental tasks. These results extend the reasoning-based approach, stressing that it might not be the representation of length that is impaired in LBD patients, but rather the ability to generate mechanical actions based on physical object properties. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

Selective attention affects conceptual object priming and recognition: a study with young and older adults.

PubMed

Ballesteros, Soledad; Mayas, Julia

2014-01-01

In the present study, we investigated the effects of selective attention at encoding on conceptual object priming (Experiment 1) and old-new recognition memory (Experiment 2) tasks in young and older adults. The procedures of both experiments included encoding and memory test phases separated by a short delay. At encoding, the picture outlines of two familiar objects, one in blue and the other in green, were presented to the left and to the right of fixation. In Experiment 1, participants were instructed to attend to the picture outline of a certain color and to classify the object as natural or artificial. After a short delay, participants performed a natural/artificial speeded conceptual classification task with repeated attended, repeated unattended, and new pictures. In Experiment 2, participants at encoding memorized the attended pictures and classify them as natural or artificial. After the encoding phase, they performed an old-new recognition memory task. Consistent with previous findings with perceptual priming tasks, we found that conceptual object priming, like explicit memory, required attention at encoding. Significant priming was obtained in both age groups, but only for those pictures that were attended at encoding. Although older adults were slower than young adults, both groups showed facilitation for attended pictures. In line with previous studies, young adults had better recognition memory than older adults.

Selective attention affects conceptual object priming and recognition: a study with young and older adults

PubMed Central

Ballesteros, Soledad; Mayas, Julia

2015-01-01

In the present study, we investigated the effects of selective attention at encoding on conceptual object priming (Experiment 1) and old–new recognition memory (Experiment 2) tasks in young and older adults. The procedures of both experiments included encoding and memory test phases separated by a short delay. At encoding, the picture outlines of two familiar objects, one in blue and the other in green, were presented to the left and to the right of fixation. In Experiment 1, participants were instructed to attend to the picture outline of a certain color and to classify the object as natural or artificial. After a short delay, participants performed a natural/artificial speeded conceptual classification task with repeated attended, repeated unattended, and new pictures. In Experiment 2, participants at encoding memorized the attended pictures and classify them as natural or artificial. After the encoding phase, they performed an old–new recognition memory task. Consistent with previous findings with perceptual priming tasks, we found that conceptual object priming, like explicit memory, required attention at encoding. Significant priming was obtained in both age groups, but only for those pictures that were attended at encoding. Although older adults were slower than young adults, both groups showed facilitation for attended pictures. In line with previous studies, young adults had better recognition memory than older adults. PMID:25628588

Effects of age on a real-world What-Where-When memory task

PubMed Central

Mazurek, Adèle; Bhoopathy, Raja Meenakshi; Read, Jenny C. A.; Gallagher, Peter; Smulders, Tom V.

2015-01-01

Many cognitive abilities decline with aging, making it difficult to detect pathological changes against a background of natural changes in cognition. Most of the tests to assess cognitive decline are artificial tasks that have little resemblance to the problems faced by people in everyday life. This means both that people may have little practice doing such tasks (potentially contributing to the decline in performance) and that the tasks may not be good predictors of real-world cognitive problems. In this study, we test the performance of young people (18–25 years) and older people (60+-year-olds) on a novel, more ecologically valid test of episodic memory: the real-world What-Where-When (WWW) memory test. We also compare them on a battery of other cognitive tests, including working memory, psychomotor speed, executive function, and episodic memory. Older people show the expected age-related declines on the test battery. In the WWW memory task, older people were more likely to fail to remember any WWW combination than younger people were, although they did not significantly differ in their overall WWW score due to some older people performing as well as or better than most younger people. WWW memory performance was significantly predicted by other measures of episodic memory, such as the single-trial learning and long-term retention in the Rey Auditory Verbal Learning task and Combined Object Location Memory in the Object Relocation task. Self-reported memory complaints also predicted performance on the WWW task. These findings confirm that our real-world WWW memory task is a valid measure of episodic memory, with high ecological validity, which may be useful as a predictor of everyday memory abilities. The task will require a bit more development to improve its sensitivity to cognitive declines in aging and to potentially distinguish between mentally healthy older adults and those with early signs of cognitive pathologies. PMID:26042030

Measuring listening effort: driving simulator vs. simple dual-task paradigm

PubMed Central

Wu, Yu-Hsiang; Aksan, Nazan; Rizzo, Matthew; Stangl, Elizabeth; Zhang, Xuyang; Bentler, Ruth

2014-01-01

Objectives The dual-task paradigm has been widely used to measure listening effort. The primary objectives of the study were to (1) investigate the effect of hearing aid amplification and a hearing aid directional technology on listening effort measured by a complicated, more real world dual-task paradigm, and (2) compare the results obtained with this paradigm to a simpler laboratory-style dual-task paradigm. Design The listening effort of adults with hearing impairment was measured using two dual-task paradigms, wherein participants performed a speech recognition task simultaneously with either a driving task in a simulator or a visual reaction-time task in a sound-treated booth. The speech materials and road noises for the speech recognition task were recorded in a van traveling on the highway in three hearing aid conditions: unaided, aided with omni directional processing (OMNI), and aided with directional processing (DIR). The change in the driving task or the visual reaction-time task performance across the conditions quantified the change in listening effort. Results Compared to the driving-only condition, driving performance declined significantly with the addition of the speech recognition task. Although the speech recognition score was higher in the OMNI and DIR conditions than in the unaided condition, driving performance was similar across these three conditions, suggesting that listening effort was not affected by amplification and directional processing. Results from the simple dual-task paradigm showed a similar trend: hearing aid technologies improved speech recognition performance, but did not affect performance in the visual reaction-time task (i.e., reduce listening effort). The correlation between listening effort measured using the driving paradigm and the visual reaction-time task paradigm was significant. The finding showing that our older (56 to 85 years old) participants’ better speech recognition performance did not result in reduced listening effort was not consistent with literature that evaluated younger (approximately 20 years old), normal hearing adults. Because of this, a follow-up study was conducted. In the follow-up study, the visual reaction-time dual-task experiment using the same speech materials and road noises was repeated on younger adults with normal hearing. Contrary to findings with older participants, the results indicated that the directional technology significantly improved performance in both speech recognition and visual reaction-time tasks. Conclusions Adding a speech listening task to driving undermined driving performance. Hearing aid technologies significantly improved speech recognition while driving, but did not significantly reduce listening effort. Listening effort measured by dual-task experiments using a simulated real-world driving task and a conventional laboratory-style task was generally consistent. For a given listening environment, the benefit of hearing aid technologies on listening effort measured from younger adults with normal hearing may not be fully translated to older listeners with hearing impairment. PMID:25083599

Creating Simple Windchill Admin Tools Using Info*Engine

NASA Technical Reports Server (NTRS)

Jones, Corey; Kapatos, Dennis; Skradski, Cory

2012-01-01

Being a Windchill administrator often requires performing simple yet repetitive tasks on large sets of objects. These can include renaming, deleting, checking in, undoing checkout, and much more. This is especially true during a migration. Fortunately, PTC has provided a simple way to dynamically interact with Windchill using Info*Engine. This presentation will describe how to create simple Info*Engine tasks capable of saving Windchill 10.0 administrators hours of tedious work. It will also show how these tasks can be combined and displayed on a simple JSP page that acts as a "Windchill Administrator Dashboard/Toolbox". The attendee will learn some valuable tasks Info*Engine capable of performing. The attendee will gain a basic understanding of how to perform and implement Info*Engine tasks. The attendee will learn what's involved in creating a JSP page that displays Info*Engine tasks

The parietal cortices participate in encoding, short-term memory, and decision-making related to tactile shape.

PubMed

Rojas-Hortelano, Eduardo; Concha, Luis; de Lafuente, Victor

2014-10-15

We routinely identify objects with our hands, and the physical attributes of touched objects are often held in short-term memory to aid future decisions. However, the brain structures that selectively process tactile information to encode object shape are not fully identified. In this article we describe the areas within the human cerebral cortex that specialize in encoding, short-term memory, and decision-making related to the shape of objects explored with the hand. We performed event-related functional magnetic resonance imaging in subjects performing a shape discrimination task in which two sequentially presented objects had to be explored to determine whether they had the same shape or not. To control for low-level and nonspecific brain activations, subjects performed a temperature discrimination task in which they compared the temperature of two spheres. Our results show that although a large network of brain structures is engaged in somatosensory processing, it is the areas lining the intraparietal sulcus that selectively participate in encoding, maintaining, and deciding on tactile information related to the shape of objects. Copyright © 2014 the American Physiological Society.

Structural encoding processes contribute to individual differences in face and object cognition: Inferences from psychometric test performance and event-related brain potentials.

PubMed

Nowparast Rostami, Hadiseh; Sommer, Werner; Zhou, Changsong; Wilhelm, Oliver; Hildebrandt, Andrea

2017-10-01

The enhanced N1 component in event-related potentials (ERP) to face stimuli, termed N170, is considered to indicate the structural encoding of faces. Previously, individual differences in the latency of the N170 have been related to face and object cognition abilities. By orthogonally manipulating content domain (faces vs objects) and task demands (easy/speed vs difficult/accuracy) in both psychometric and EEG tasks, we investigated the uniqueness of the processes underlying face cognition as compared with object cognition and the extent to which the N1/N170 component can explain individual differences in face and object cognition abilities. Data were recorded from N = 198 healthy young adults. Structural equation modeling (SEM) confirmed that the accuracies of face perception (FP) and memory are specific abilities above general object cognition; in contrast, the speed of face processing was not differentiable from the speed of object cognition. Although there was considerable domain-general variance in the N170 shared with the N1, there was significant face-specific variance in the N170. The brain-behavior relationship showed that faster face-specific processes for structural encoding of faces are associated with higher accuracy in both perceiving and memorizing faces. Moreover, in difficult task conditions, qualitatively different processes are additionally needed for recognizing face and object stimuli as compared with easy tasks. The difficulty-dependent variance components in the N170 amplitude were related with both face and object memory (OM) performance. We discuss implications for understanding individual differences in face cognition. Copyright © 2017 Elsevier Ltd. All rights reserved.

Correlation between observation task performance and visual acuity, contrast sensitivity and environmental light in a simulated maritime study.

PubMed

Koefoed, Vilhelm F; Assmuss, Jörg; Høvding, Gunnar

2018-03-25

To examine the relevance of visual acuity (VA) and index of contrast sensitivity (ICS) as predictors for visual observation task performance in a maritime environment. Sixty naval cadets were recruited to a study on observation tasks in a simulated maritime environment under three different light settings. Their ICS were computed based on contrast sensitivity (CS) data recorded by Optec 6500 and CSV-1000E CS tests. The correlation between object identification distance and VA/ICS was examined by stepwise linear regression. The object detection distance was significantly correlated to the level of environmental light (p < 0.001), but not to the VA or ICS recorded in the test subjects. Female cadets had a significantly shorter target identification range than the male cadets. Neither CS nor VA were found to be significantly correlated to observation task performance. This apparent absence of proven predictive value of visual parameters for observation tasks in a maritime environment may presumably be ascribed to the normal and uniform visual capacity in all our study subjects. © 2018 Acta Ophthalmologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.

Relations between Semantic and Cognitive Development in the One-Word Stage: The Specificity Hypothesis.

ERIC Educational Resources Information Center

Gopnik, Alison; Meltzoff, Andrew N.

1986-01-01

Compares two types of semantic development (the acquisition of disappearance words and success-failure words) to performance on two types of cognitive tasks (object-permanence and means-ends tasks) among infants. (HOD)

Dependence of behavioral performance on material category in an object grasping task with monkeys.

PubMed

Yokoi, Isao; Tachibana, Atsumichi; Minamimoto, Takafumi; Goda, Naokazu; Komatsu, Hidehiko

2018-05-02

Material perception is an essential part of our cognitive function that enables us to properly interact with our complex daily environment. One important aspect of material perception is its multimodal nature. When we see an object, we generally recognize its haptic properties as well as its visual properties. Consequently, one must examine behavior using real objects that are perceived both visually and haptically to fully understand the characteristics of material perception. As a first step, we examined whether there is any difference in the behavioral responses to different materials in monkeys trained to perform an object grasping task in which they saw and grasped rod-shaped real objects made of various materials. We found that the monkeys' behavior in the grasping task, measured based on the success rate and the pulling force, differed depending on the material category. Monkeys easily and correctly grasped objects of some materials, such as metal and glass, but failed to grasp objects of other materials. In particular, monkeys avoided grasping fur-covered objects. The differences in the behavioral responses to the material categories cannot be explained solely based on the degree of familiarity with the different materials. These results shed light on the organization of multimodal representation of materials, where their biological significance is an important factor. In addition, a monkey that avoided touching real fur-covered objects readily touched images of the same objects presented on a CRT display. This suggests employing real objects is important when studying behaviors related to material perception.

Task partitioning in a robot swarm: object retrieval as a sequence of subtasks with direct object transfer.

PubMed

Pini, Giovanni; Brutschy, Arne; Scheidler, Alexander; Dorigo, Marco; Birattari, Mauro

2014-01-01

We study task partitioning in the context of swarm robotics. Task partitioning is the decomposition of a task into subtasks that can be tackled by different workers. We focus on the case in which a task is partitioned into a sequence of subtasks that must be executed in a certain order. This implies that the subtasks must interface with each other, and that the output of a subtask is used as input for the subtask that follows. A distinction can be made between task partitioning with direct transfer and with indirect transfer. We focus our study on the first case: The output of a subtask is directly transferred from an individual working on that subtask to an individual working on the subtask that follows. As a test bed for our study, we use a swarm of robots performing foraging. The robots have to harvest objects from a source, situated in an unknown location, and transport them to a home location. When a robot finds the source, it memorizes its position and uses dead reckoning to return there. Dead reckoning is appealing in robotics, since it is a cheap localization method and it does not require any additional external infrastructure. However, dead reckoning leads to errors that grow in time if not corrected periodically. We compare a foraging strategy that does not make use of task partitioning with one that does. We show that cooperation through task partitioning can be used to limit the effect of dead reckoning errors. This results in improved capability of locating the object source and in increased performance of the swarm. We use the implemented system as a test bed to study benefits and costs of task partitioning with direct transfer. We implement the system with real robots, demonstrating the feasibility of our approach in a foraging scenario.

Psychomotor performance measured in a virtual environment correlates with technical skills in the operating room.

PubMed

Kundhal, Pavi S; Grantcharov, Teodor P

2009-03-01

This study was conducted to validate the role of virtual reality computer simulation as an objective method for assessing laparoscopic technical skills. The authors aimed to investigate whether performance in the operating room, assessed using a modified Objective Structured Assessment of Technical Skill (OSATS), correlated with the performance parameters registered by a virtual reality laparoscopic trainer (LapSim). The study enrolled 10 surgical residents (3 females) with a median of 5.5 years (range, 2-6 years) since graduation who had similar limited experience in laparoscopic surgery (median, 5; range, 1-16 laparoscopic cholecystectomies). All the participants performed three repetitions of seven basic skills tasks on the LapSim laparoscopic trainer and one laparoscopic cholecystectomy in the operating room. The operating room procedure was video recorded and blindly assessed by two independent observers using a modified OSATS rating scale. Assessment in the operating room was based on three parameters: time used, error score, and economy of motion score. During the tasks on the LapSim, time, error (tissue damage and millimeters of tissue damage [tasks 2-6], error score [incomplete target areas, badly placed clips, and dropped clips [task 7]), and economy of movement parameters (path length and angular path) were registered. The correlation between time, economy, and error parameters during the simulated tasks and the operating room procedure was statistically assessed using Spearman's test. Significant correlations were demonstrated between the time used to complete the operating room procedure and time used for task 7 (r (s) = 0.74; p = 0.015). The error score demonstrated during the laparoscopic cholecystectomy correlated well with the tissue damage in three of the seven tasks (p < 0.05), the millimeters of tissue damage during two of the tasks, and the error score in task 7 (r (s) = 0.67; p = 0.034). Furthermore, statistically significant correlations were observed between the economy of motion score from the operative procedure and LapSim's economy parameters (path length and angular path in six of the tasks) (p < 0.05). The current study demonstrated significant correlations between operative performance in the operating room (assessed using a well-validated rating scale) and psychomotor performance in virtual environment assessed by a computer simulator. This provides strong evidence for the validity of the simulator system as an objective tool for assessing laparoscopic skills. Virtual reality simulation can be used in practice to assess technical skills relevant for minimally invasive surgery.

Sensory Processing Relates to Attachment to Childhood Comfort Objects of College Students

ERIC Educational Resources Information Center

Kalpidou, Maria

2012-01-01

The author tested the hypothesis that attachment to comfort objects is based on the sensory processing characteristics of the individual. Fifty-two undergraduate students with and without a childhood comfort object reported sensory responses and performed a tactile threshold task. Those with a comfort object described their object and rated their…

Human Performance in Continuous/Sustained Operations and the Demands of Extended Work/Rest Schedules: An Annotated Bibliography. Volume 2

DTIC Science & Technology

1989-06-01

subjective self -report questionnaires and more objective activity measures to estimate the amount of sleep obtained. The aim of the study was to determine...helicopter crews were observed and analyzed. It is concluded that the operational effiency of flight crews can be obtained by adopting four measures...task on simulated truck- driving task performance. Human factors. 27(2): 201-207. A study examined the effects of extra task stimulation and extra

Integration of task level planning and diagnosis for an intelligent robot

NASA Technical Reports Server (NTRS)

Chan, Amy W.

1992-01-01

A satellite floating space is diagnosed with a telerobot attached performing maintenance or replacement tasks. This research included three objectives. The first objective was to generate intelligent path planning for a robot to move around a satellite. The second objective was to diagnose possible faulty scenarios in the satellite. The third objective included two tasks. The first task was to combine intelligent path planning with diagnosis. The second task was to build an interface between the combined intelligent system with Robosim. The ability of a robot to deal with unexpected scenarios is particularly important in space since the situation could be different from time to time so that the telerobot must be capable of detecting that the situation has changed and the necessity may exist to alter its behavior based on the new situation. The feature of allowing human-in-the-loop is also very important in space. In some extreme cases, the situation is beyond the capability of a robot so our research project allows the human to override the decision of a robot.

Retro-cue benefits in working memory without sustained focal attention.

PubMed

Rerko, Laura; Souza, Alessandra S; Oberauer, Klaus

2014-07-01

In working memory (WM) tasks, performance can be boosted by directing attention to one memory object: When a retro-cue in the retention interval indicates which object will be tested, responding is faster and more accurate (the retro-cue benefit). We tested whether the retro-cue benefit in WM depends on sustained attention to the cued object by inserting an attention-demanding interruption task between the retro-cue and the memory test. In the first experiment, the interruption task required participants to shift their visual attention away from the cued representation and to a visual classification task on colors. In the second and third experiments, the interruption task required participants to shift their focal attention within WM: Attention was directed away from the cued representation by probing another representation from the memory array prior to probing the cued object. The retro-cue benefit was not attenuated by shifts of perceptual attention or by shifts of attention within WM. We concluded that sustained attention is not needed to maintain the cued representation in a state of heightened accessibility.

Enumeration versus multiple object tracking: the case of action video game players

PubMed Central

Green, C.S.; Bavelier, D.

2010-01-01

Here, we demonstrate that action video game play enhances subjects’ ability in two tasks thought to indicate the number of items that can be apprehended. Using an enumeration task, in which participants have to determine the number of quickly flashed squares, accuracy measures showed a near ceiling performance for low numerosities and a sharp drop in performance once a critical number of squares was reached. Importantly, this critical number was higher by about two items in video game players (VGPs) than in non-video game players (NVGPs). A following control study indicated that this improvement was not due to an enhanced ability to instantly apprehend the numerosity of the display, a process known as subitizing, but rather due to an enhancement in the slower more serial process of counting. To confirm that video game play facilitates the processing of multiple objects at once, we compared VGPs and NVGPs on the multiple object tracking task (MOT), which requires the allocation of attention to several items over time. VGPs were able to successfully track approximately two more items than NVGPs. Furthermore, NVGPs trained on an action video game established the causal effect of game playing in the enhanced performance on the two tasks. Together, these studies confirm the view that playing action video games enhances the number of objects that can be apprehended and suggest that this enhancement is mediated by changes in visual short-term memory skills. PMID:16359652

Enumeration versus multiple object tracking: the case of action video game players.

PubMed

Green, C S; Bavelier, D

2006-08-01

Here, we demonstrate that action video game play enhances subjects' ability in two tasks thought to indicate the number of items that can be apprehended. Using an enumeration task, in which participants have to determine the number of quickly flashed squares, accuracy measures showed a near ceiling performance for low numerosities and a sharp drop in performance once a critical number of squares was reached. Importantly, this critical number was higher by about two items in video game players (VGPs) than in non-video game players (NVGPs). A following control study indicated that this improvement was not due to an enhanced ability to instantly apprehend the numerosity of the display, a process known as subitizing, but rather due to an enhancement in the slower more serial process of counting. To confirm that video game play facilitates the processing of multiple objects at once, we compared VGPs and NVGPs on the multiple object tracking task (MOT), which requires the allocation of attention to several items over time. VGPs were able to successfully track approximately two more items than NVGPs. Furthermore, NVGPs trained on an action video game established the causal effect of game playing in the enhanced performance on the two tasks. Together, these studies confirm the view that playing action video games enhances the number of objects that can be apprehended and suggest that this enhancement is mediated by changes in visual short-term memory skills.

After-effects of TFT-LCD display polarity and display colour on the detection of low-contrast objects.

PubMed

Mayr, Susanne; Buchner, Axel

2010-07-01

Participants performed a word-non-word discrimination task within a car control display emulated on a thin film transistor liquid-crystal display (TFT-LCD). The task simulated an information read-out from a TFT-LCD-based instrument panel. Subsequently, participants performed a low-contrast object detection task that simulated the detection of objects during night-time driving. In experiment 1, words/non-words were presented black-on-white (positive polarity) or white-on-black (negative polarity). In experiments 2 and 3, display colour was additionally manipulated. A positive polarity advantage in the discrimination task was consistently observed. In contrast, positive displays interfered more than negative displays with subsequent detection. The detrimental after-effect of positive polarity displays was strong with white and blue, reduced with amber and absent with red displays. Subjective measures showed a preference for blue over red, but a slight advantage for amber over blue. Implications for TFT-LCD design are derived from the results. STATEMENT OF RELEVANCE: When using TFT-LCDs as car instrument panels, positive polarity red TFT-LCDs are very likely to lead to good instrument readability while at the same time minimising - relative to other colours - the negative effects of an illuminated display on low-contrast object detection during night-time driving.

The impact of attentional, linguistic, and visual features during object naming

PubMed Central

Clarke, Alasdair D. F.; Coco, Moreno I.; Keller, Frank

2013-01-01

Object detection and identification are fundamental to human vision, and there is mounting evidence that objects guide the allocation of visual attention. However, the role of objects in tasks involving multiple modalities is less clear. To address this question, we investigate object naming, a task in which participants have to verbally identify objects they see in photorealistic scenes. We report an eye-tracking study that investigates which features (attentional, visual, and linguistic) influence object naming. We find that the amount of visual attention directed toward an object, its position and saliency, along with linguistic factors such as word frequency, animacy, and semantic proximity, significantly influence whether the object will be named or not. We then ask how features from different modalities are combined during naming, and find significant interactions between saliency and position, saliency and linguistic features, and attention and position. We conclude that when the cognitive system performs tasks such as object naming, it uses input from one modality to constraint or enhance the processing of other modalities, rather than processing each input modality independently. PMID:24379792

Cognitive correlates of spatial navigation: Associations between executive functioning and the virtual Morris Water Task.

PubMed

Korthauer, L E; Nowak, N T; Frahmand, M; Driscoll, I

2017-01-15

Although effective spatial navigation requires memory for objects and locations, navigating a novel environment may also require considerable executive resources. The present study investigated associations between performance on the virtual Morris Water Task (vMWT), an analog version of a nonhuman spatial navigation task, and neuropsychological tests of executive functioning and spatial performance in 75 healthy young adults. More effective vMWT performance (e.g., lower latency and distance to reach hidden platform, greater distance in goal quadrant on a probe trial, fewer path intersections) was associated with better verbal fluency, set switching, response inhibition, and ability to mentally rotate objects. Findings also support a male advantage in spatial navigation, with sex moderating several associations between vMWT performance and executive abilities. Overall, we report a robust relationship between executive functioning and navigational skill, with some evidence that men and women may differentially recruit cognitive abilities when navigating a novel environment. Copyright © 2016 Elsevier B.V. All rights reserved.

Age, familiarity, and visual processing schemes.

PubMed

De Haven, D T; Roberts-Gray, C

1978-10-01

In a partial-report task adults and 5-yr.-old children identified stimuli of two types (common objects and familiar common objects) in two representations (black-and-white line drawings or full color photographs). It was hypothesized that familiar items and photographic representation would enhance the children's accuracy. Although both children and adults were more accurate when the stimuli were from the familiar set, children performed more accurate when the stimuli were from the familiar set, children performed poorly in all stimulus conditions. Results suggest that the age difference in this task reflects the "concrete" nature of the perceptual process in children.

Visual skills in airport-security screening.

PubMed

McCarley, Jason S; Kramer, Arthur F; Wickens, Christopher D; Vidoni, Eric D; Boot, Walter R

2004-05-01

An experiment examined visual performance in a simulated luggage-screening task. Observers participated in five sessions of a task requiring them to search for knives hidden in x-ray images of cluttered bags. Sensitivity and response times improved reliably as a result of practice. Eye movement data revealed that sensitivity increases were produced entirely by changes in observers' ability to recognize target objects, and not by changes in the effectiveness of visual scanning. Moreover, recognition skills were in part stimulus-specific, such that performance was degraded by the introduction of unfamiliar target objects. Implications for screener training are discussed.

Object Boundaries Influence Toddlers' Performance in a Search Task

ERIC Educational Resources Information Center

Shutts, Kristin; Keen, Rachel; Spelke, Elizabeth S.

2006-01-01

Previous research has shown that young children have difficulty searching for a hidden object whose location depends on the position of a partly visible physical barrier. Across four experiments, we tested whether children's search errors are affected by two variables that influence adults' object-directed attention: object boundaries and…

An evaluation of nursing tasks.

PubMed

Baptiste, Andrea

2011-01-01

Functional capacity evaluations have been criticized as being too general in theory and not being accurate enough to determine what tasks an employee can perform. This paper will describe results of a descriptive study that was conducted in a laboratory setting to objectively determine the physical demands of patient transfer tasks performed by nurses. Fifty three tasks were analyzed and broken down into sub-tasks to quantify the peak force required to perform each sub-task in order to determine which tasks pose healthcare workers at highest risk of injury. Dissecting the transfer task into segments allows us to see which part of the task requires high forces on the part of the caregiver. The task can then be modified to eliminate the risk of injury to the caregiver. This modification can be accomplished by using healthcare technology, such as floor based or overhead lifts, friction reducing devices, sit to stand lifts, properly designed slings, and motorized beds/trolleys. Technological solutions are available for some of these high risk tasks and should be implemented where applicable to reduce the force demand and eliminate or reduce the risk of injury to healthcare workers in nursing.

Efficiency in Rule- vs. Plan-Based Movements Is Modulated by Action-Mode.

PubMed

Scheib, Jean P P; Stoll, Sarah; Thürmer, J Lukas; Randerath, Jennifer

2018-01-01

The rule/plan motor cognition (RPMC) paradigm elicits visually indistinguishable motor outputs, resulting from either plan- or rule-based action-selection, using a combination of essentially interchangeable stimuli. Previous implementations of the RPMC paradigm have used pantomimed movements to compare plan- vs. rule-based action-selection. In the present work we attempt to determine the generalizability of previous RPMC findings to real object interaction by use of a grasp-to-rotate task. In the plan task, participants had to use prospective planning to achieve a comfortable post-handle rotation hand posture. The rule task used implementation intentions (if-then rules) leading to the same comfortable end-state. In Experiment A, we compare RPMC performance of 16 healthy participants in pantomime and real object conditions of the experiment, within-subjects. Higher processing efficiency of rule- vs. plan-based action-selection was supported by diffusion model analysis. Results show a significant response-time increase in the pantomime condition compared to the real object condition and a greater response-time advantage of rule-based vs. plan-based actions in the pantomime compared to the real object condition. In Experiment B, 24 healthy participants performed the real object RPMC task in a task switching vs. a blocked condition. Results indicate that plan-based action-selection leads to longer response-times and less efficient information processing than rule-based action-selection in line with previous RPMC findings derived from the pantomime action-mode. Particularly in the task switching mode, responses were faster in the rule compared to the plan task suggesting a modulating influence of cognitive load. Overall, results suggest an advantage of rule-based action-selection over plan-based action-selection; whereby differential mechanisms appear to be involved depending on the action-mode. We propose that cognitive load is a factor that modulates the advantageous effect of implementation intentions in motor cognition on different levels as illustrated by the varying speed advantages and the variation in diffusion parameters per action-mode or condition, respectively.

Differential effects of social and novelty enrichment on individual differences in impulsivity and behavioral flexibility.

PubMed

Wang, Maya Zhe; Marshall, Andrew T; Kirkpatrick, Kimberly

2017-06-01

Early life experience profoundly impacts behavior and cognitive functions in rats. The present study investigated how the presence of conspecifics and/or novel objects, could independently influence individual differences in impulsivity and behavioral flexibility. Twenty-four rats were reared in an isolated condition, an isolated condition with a novel object, a pair-housed social condition, or a pair-housed social condition with a novel object. The rats were then tested on an impulsive choice task, a behavioral flexibility task, and an impulsive action task. Novelty enrichment produced an overall increase in impulsive choice, while social enrichment decreased impulsive choice in the absence of novelty enrichment and also produced an overall increase in impulsive action. In the behavioral flexibility task, social enrichment increased regressive errors, whereas both social and novelty enrichment reduced never-reinforced errors. Individual differences analyses indicated a significant relationship between performance in the behavioral flexibility and impulsive action tasks, which may reflect a common psychological correlate of action inhibition. Moreover, there was a relationship between delay sensitivity in the impulsive choice task and performance on the DRL and behavioral flexibility tasks, suggesting a dual role for timing and inhibitory processes in driving the interrelationship between these tasks. Overall, these results indicate that social and novelty enrichment produce distinct effects on impulsivity and adaptability, suggesting the need to parse out the different elements of enrichment in future studies. Further research is warranted to better understand how individual differences in sensitivity to enrichment affect individuals' interactions with and the resulting consequences of the rearing environment. Copyright © 2017 Elsevier B.V. All rights reserved.

Differential effects of social and novelty enrichment on individual differences in impulsivity and behavioral flexibility

PubMed Central

Wang, Maya Zhe; Marshall, Andrew T.; Kirkpatrick, Kimberly

2017-01-01

Early life experience profoundly impacts behavior and cognitive functions in rats. The present study investigated how the presence of conspecifics and/or novel objects, could independently influence individual differences in impulsivity and behavioral flexibility. Twenty-four rats were reared in an isolated condition, an isolated condition with a novel object, a pair-housed social condition, or a pair-housed social condition with a novel object. The rats were then tested on an impulsive choice task, a behavioral flexibility task, and an impulsive action task. Novelty enrichment produced an overall increase in impulsive choice, while social enrichment decreased impulsive choice in the absence of novelty enrichment and also produced an overall increase in impulsive action. In the behavioral flexibility task, social enrichment increased regressive errors, whereas both social and novelty enrichment reduced never reinforced errors. Individual differences analyses indicated a significant relationship between performance in the behavioral flexibility and impulsive action tasks, which may reflect a common psychological correlate of action inhibition. Moreover, there was a relationship between delay sensitivity in the impulsive choice task and performance on the DRL and behavioral flexibility tasks, suggesting a dual role for timing and inhibitory processes in driving the interrelationship between these tasks. Overall, these results indicate that social and novelty enrichment produce distinct effects on impulsivity and adaptability, suggesting the need to parse out the different elements of enrichment in future studies. Further research is warranted to better understand how individual differences in sensitivity to enrichment affect individuals’ interactions with and the resulting consequences of the rearing environment. PMID:28341610

Material-specific difficulties in episodic memory tasks in mild traumatic brain injury.

PubMed

Tsirka, Vassiliki; Simos, Panagiotis; Vakis, Antonios; Vourkas, Michael; Arzoglou, Vasileios; Syrmos, Nikolaos; Stavropoulos, Stavros; Micheloyannis, Sifis

2010-03-01

The study examines acute, material-specific secondary memory performance in 26 patients with mild traumatic brain injury (MTBI) and 26 healthy controls, matched on demographic variables and indexes of crystallized intelligence. Neuropsychological tests were used to evaluate primary and secondary memory, executive functions, and verbal fluency. Participants were also tested on episodic memory tasks involving words, pseudowords, pictures of common objects, and abstract kaleidoscopic images. Patients showed reduced performance on episodic memory measures, and on tasks associated with visuospatial processing and executive function (Trail Making Test part B, semantic fluency). Significant differences between groups were also noted for correct rejections and response bias on the kaleidoscope task. MTBI patients' reduced performance on memory tasks for complex, abstract stimuli can be attributed to a dysfunction in the strategic component of memory process.

The Effect of Question Format and Task Difficulty on Reasoning Strategies and Diagnostic Performance in Internal Medicine Residents

ERIC Educational Resources Information Center

Heemskerk, Laura; Norman, Geoff; Chou, Sophia; Mintz, Marcy; Mandin, Henry; McLaughlin, Kevin

2008-01-01

Background: Previous studies have suggested an association between reasoning strategies and diagnostic success, but the influence on this relationship of variables such as question format and task difficulty, has not been studied. Our objective was to study the association between question format, task difficulty, reasoning strategies and…

Raised visual detection thresholds depend on the level of complexity of cognitive foveal loading.

PubMed

Plainis, S; Murray, I J; Chauhan, K

2001-01-01

The objective of the study was to measure the interactions between visual thresholds for a simple light (the secondary task) presented peripherally and a simultaneously performed cognitive task (the primary task) presented foveally The primary task was highly visible but varied according to its cognitive complexity. Interactions between the tasks were determined by measuring detection thresholds for the peripheral task and accuracy of performance of the foveal task. Effects were measured for 5, 10, 20, and 30 deg eccentricity of the peripherally presented light and for three levels of cognitive complexity. Mesopic conditions (0.5 lx) were used. As expected, the concurrent presentation of the foveal cognitive task reduced peripheral sensitivity. Moreover, performance of the foveal task was adversely affected when conducting the peripheral task. Performance on both tasks was reduced as the level of complexity of the cognitive task increased. There were qualitative differences in task interactions between the central 10 deg and at greater eccentricities. Within 10 deg there was a disproportionate effect of eccentricity, previously interpreted as the 'tunnel-vision' model of visual field narrowing. Interactions outside 10 deg were less affected by eccentricity. These results are discussed in terms of the known neurophysiological characteristics of the primary visual pathway.

Body Unloading Associated with Space Flight and Bed-rest Impacts Functional Performance

NASA Technical Reports Server (NTRS)

Bloomberg, J. J.; Ballard, K. L.; Batson, C. D.; Buxton, R. E.; Feiveson, A. H.; Kofman, I. S.; Lee, S. M. C.; Miller, C. A.; Mulavara, A. P.; Peters, B. T.;

Enhancement of object-permanence performance in the Down's syndrome infant.

PubMed

Morss, J R

1984-01-01

Four infants with Down's syndrome (aged 19-33 months) were presented with a restructured version of an object-permanence task. Restructuring consisted of the embedding of single trials of the task within a sequence of simpler, related steps. Following failure on a standard presentation of the task, three Down's syndrome (DS) infants demonstrated success on trials embedded in the training sequence. Comparison was made with the performance of normal infants (aged 14-19 months) matched in terms of failure on the pre-test. Only two out of nine normal infants registered success on the embedded trials. Results are discussed in terms of the differences between the DS infant and the normal infant, and the former's reliance on the deliberate structuring of his learning environment by a parent or educator.

Using link analysis to explore the impact of the physical environment on pharmacist tasks.

PubMed

Lester, Corey A; Chui, Michelle A

2016-01-01

National community pharmacy organizations have been redesigning pharmacies to better facilitate direct patient care. However, evidence suggests that changing the physical layout of a pharmacy prior to understanding how the environment impacts pharmacists' work may not achieve the desired benefits. This study describes an objective method to understanding how the physical layout of the pharmacy may affect how pharmacists perform tasks. Link analysis is a systems engineering method used to describe the influence of the physical environment on task completion. This study used a secondary data set of field notes collected from 9 h of direct observation in one mass-merchandise community pharmacy in the U.S. State, Wisconsin. A node is an individual location in the environment. A link is the movement between two nodes. Tasks were inventoried and task themes identified. The mean, minimum, and maximum number of links needed to complete each task were then determined and used to construct a link table. A link diagram is a graphical display showing the links in conjunction with the physical layout of the pharmacy. A total of 92 unique tasks were identified resulting in 221 links. Tasks were sorted into five themes: patient care activities, insurance issues, verifying prescriptions, filling prescriptions, and other. Insurance issues required the greatest number of links with a mean of 4.75. Verifying prescriptions and performing patient care were the most commonly performed tasks with 36 and 30 unique task occurrences, respectively. Link analysis provides an objective method for identifying how a pharmacist interacts with the physical environment to complete tasks. This method provides designers with useful information to target interventions to improve the effectiveness of pharmacist work. Analysis beyond link analysis should be considered for large scale system redesign. Copyright © 2015 Elsevier Inc. All rights reserved.

Spatial short-term memory is impaired in dependent betel quid chewers.

PubMed

Chiu, Meng-Chun; Shen, Bin; Li, Shuo-Heng; Ho, Ming-Chou

2016-08-01

Betel quid is regarded as a human carcinogen by the World Health Organization. It remains unknown whether chewing betel quid has a chronic effect on healthy betel quid chewers' memory. The present study aims to investigate whether chewing betel quid can affect short-term memory (STM). Three groups of participants (24 dependent chewers, 24 non-dependent chewers, and 24 non-chewers) were invited to carry out the matrix span task, the object span task, and the digit span task. All span tasks' results were adopted to assess spatial STM, visual STM, and verbal STM, respectively. Besides, there are three set sizes (small, medium, and large) in each span task. For the matrix span task, results showed that the dependent chewers had worse performances than the non-dependent chewers and the non-chewers at medium and large set sizes. For the object span task and digit span task, there were no differences in between groups. In each group, recognition performances were worse with the increasing set size and showing successful manipulation of memory load. The current study provided the first evidence that dependent betel quid chewing can selectively impair spatial STM rather than visual STM and verbal STM. Theoretical and practical implications of this result are discussed.

The development of a model to predict the effects of worker and task factors on foot placements in manual material handling tasks.

PubMed

Wagner, David W; Reed, Matthew P; Chaffin, Don B

2010-11-01

Accurate prediction of foot placements in relation to hand locations during manual materials handling tasks is critical for prospective biomechanical analysis. To address this need, the effects of lifting task conditions and anthropometric variables on foot placements were studied in a laboratory experiment. In total, 20 men and women performed two-handed object transfers that required them to walk to a shelf, lift an object from the shelf at waist height and carry the object to a variety of locations. Five different changes in the direction of progression following the object pickup were used, ranging from 45° to 180° relative to the approach direction. Object weights of 1.0 kg, 4.5 kg, 13.6 kg were used. Whole-body motions were recorded using a 3-D optical retro-reflective marker-based camera system. A new parametric system for describing foot placements, the Quantitative Transition Classification System, was developed to facilitate the parameterisation of foot placement data. Foot placements chosen by the subjects during the transfer tasks appeared to facilitate a change in the whole-body direction of progression, in addition to aiding in performing the lift. Further analysis revealed that five different stepping behaviours accounted for 71% of the stepping patterns observed. More specifically, the most frequently observed behaviour revealed that the orientation of the lead foot during the actual lifting task was primarily affected by the amount of turn angle required after the lift (R(2) = 0.53). One surprising result was that the object mass (scaled by participant body mass) was not found to significantly affect any of the individual step placement parameters. Regression models were developed to predict the most prevalent step placements and are included in this paper to facilitate more accurate human motion simulations and ergonomics analyses of manual material lifting tasks. STATEMENT OF RELEVANCE: This study proposes a method for parameterising the steps (foot placements) associated with manual material handling tasks. The influence of task conditions and subject anthropometry on the foot placements of the most frequently observed stepping pattern during a laboratory study is discussed. For prospective postural analyses conducted using digital human models, accurate prediction of the foot placements is critical to realistic postural analyses and improved biomechanical job evaluations.

Family environment influences emotion recognition following paediatric traumatic brain injury

PubMed Central

SCHMIDT, ADAM T.; ORSTEN, KIMBERLEY D.; HANTEN, GERRI R.; LI, XIAOQI; LEVIN, HARVEY S.

2011-01-01

Objective This study investigated the relationship between family functioning and performance on two tasks of emotion recognition (emotional prosody and face emotion recognition) and a cognitive control procedure (the Flanker task) following paediatric traumatic brain injury (TBI) or orthopaedic injury (OI). Methods A total of 142 children (75 TBI, 67 OI) were assessed on three occasions: baseline, 3 months and 1 year post-injury on the two emotion recognition tasks and the Flanker task. Caregivers also completed the Life Stressors and Resources Scale (LISRES) on each occasion. Growth curve analysis was used to analyse the data. Results Results indicated that family functioning influenced performance on the emotional prosody and Flanker tasks but not on the face emotion recognition task. Findings on both the emotional prosody and Flanker tasks were generally similar across groups. However, financial resources emerged as significantly related to emotional prosody performance in the TBI group only (p = 0.0123). Conclusions Findings suggest family functioning variables—especially financial resources—can influence performance on an emotional processing task following TBI in children. PMID:21058900

A Male Advantage for Spatial and Object but Not Verbal Working Memory Using the N-Back Task

ERIC Educational Resources Information Center

Lejbak, Lisa; Crossley, Margaret; Vrbancic, Mirna

2011-01-01

Sex-related differences have been reported for performance and neural substrates on some working memory measures that carry a high cognitive load, including the popular n-back neuroimaging paradigm. Despite some evidence of a sex effect on the task, the influence of sex on performance represents a potential confound in neuroimaging research. The…

Developmental Progression of Looking and Reaching Performance on the A-not-B Task

PubMed Central

Cuevas, Kimberly; Bell, Martha Ann

2013-01-01

From a neuropsychological perspective, the cognitive skills of working memory, inhibition, and attention and the maturation of the frontal lobe are requisites for successful A-not-B performance on both the looking and reaching versions of the task. This study used a longitudinal design to examine the developmental progression of infants’ performance on the looking and reaching versions of the A-not-B task. Twenty infants were tested on both versions of the task once a month from 5 to 10 months of age. Infants had higher object permanence scores on the looking version of the task from 5 to 8 months, with comparable performance across response modalities at 9 and 10 months. The same pattern of performance was found on nonreversal (A) trials: Infants performed better on looking trials from 5 to 7 months and they performed equally on both response trials from 8 to 10 months. Overall, infants performed better on looking reversal (B) trials than reaching reversal trials. These data suggest that performance differences between response modalities early in development can be attributed to major differences in the maturation of brain circuitry associated with the actual task response. PMID:20822245

Social perception and aging: The relationship between aging and the perception of subtle changes in facial happiness and identity.

PubMed

Yang, Tao; Penton, Tegan; Köybaşı, Şerife Leman; Banissy, Michael J

2017-09-01

Previous findings suggest that older adults show impairments in the social perception of faces, including the perception of emotion and facial identity. The majority of this work has tended to examine performance on tasks involving young adult faces and prototypical emotions. While useful, this can influence performance differences between groups due to perceptual biases and limitations on task performance. Here we sought to examine how typical aging is associated with the perception of subtle changes in facial happiness and facial identity in older adult faces. We developed novel tasks that permitted the ability to assess facial happiness, facial identity, and non-social perception (object perception) across similar task parameters. We observe that aging is linked with declines in the ability to make fine-grained judgements in the perception of facial happiness and facial identity (from older adult faces), but not for non-social (object) perception. This pattern of results is discussed in relation to mechanisms that may contribute to declines in facial perceptual processing in older adulthood. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

Attentional Predictors of 5-month-olds' Performance on a Looking A-not-B Task.

PubMed

Marcovitch, Stuart; Clearfield, Melissa W; Swingler, Margaret; Calkins, Susan D; Bell, Martha Ann

2016-01-01

In the first year of life, the ability to search for hidden objects is an indicator of object permanence and, when multiple locations are involved, executive function (i.e. inhibition, cognitive flexibility and working memory). The current study was designed to examine attentional predictors of search in 5-month-old infants (as measured by the looking A-not-B task), and whether levels of maternal education moderated the effect of the predictors. Specifically, in a separate task, the infants were shown a unique puppet, and we measured the percentage of time attending to the puppet, as well as the length of the longest look (i.e., peak fixation) directed towards the puppet. Across the entire sample ( N =390), the percentage of time attending to the puppet was positively related to performance on the visual A-not-B task. However, for infants whose mothers had not completed college, having a shorter peak looking time (after controlling for percentage of time) was also a predictor of visual A-not-B performance. The role of attention, peak fixation and maternal education in visual search is discussed.

Cognitive-evaluative features of childhood social anxiety in a performance task.

PubMed

Tuschen-Caffier, Brunna; Kühl, Sigrid; Bender, Caroline

2011-06-01

Using an experimental design, we analysed differences in the occurrence of cognitive-evaluative distortions and performance deficits across children with social anxiety disorder, with subclinical anxiety and without any anxiety symptoms. Twenty-one children with full syndrome social phobia, 18 children with partial syndrome social phobia and 20 children without any symptoms of social phobia were compared with respect to their degree of anxiety, negative thinking and task performance during two social-evaluative tasks. In addition, self-ratings of task performance, performance estimations for other children and objective behavioural ratings by two independent observers were obtained. Children with social anxiety disorder and subclinical social anxiety showed higher degrees of experienced anxiety and negative thinking than healthy control children. There was no group difference in respect to actual task performance. Findings are discussed with regard to the continuum assumption of childhood social anxiety disorder and the need of well-adapted early interventions. Copyright © 2010. Published by Elsevier Ltd.

The relationship between visual attention and visual working memory encoding: A dissociation between covert and overt orienting.

PubMed

Tas, A Caglar; Luck, Steven J; Hollingworth, Andrew

2016-08-01

There is substantial debate over whether visual working memory (VWM) and visual attention constitute a single system for the selection of task-relevant perceptual information or whether they are distinct systems that can be dissociated when their representational demands diverge. In the present study, we focused on the relationship between visual attention and the encoding of objects into VWM. Participants performed a color change-detection task. During the retention interval, a secondary object, irrelevant to the memory task, was presented. Participants were instructed either to execute an overt shift of gaze to this object (Experiments 1-3) or to attend it covertly (Experiments 4 and 5). Our goal was to determine whether these overt and covert shifts of attention disrupted the information held in VWM. We hypothesized that saccades, which typically introduce a memorial demand to bridge perceptual disruption, would lead to automatic encoding of the secondary object. However, purely covert shifts of attention, which introduce no such demand, would not result in automatic memory encoding. The results supported these predictions. Saccades to the secondary object produced substantial interference with VWM performance, but covert shifts of attention to this object produced no interference with VWM performance. These results challenge prevailing theories that consider attention and VWM to reflect a common mechanism. In addition, they indicate that the relationship between attention and VWM is dependent on the memorial demands of the orienting behavior. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

The Relationship between Visual Attention and Visual Working Memory Encoding: A Dissociation between Covert and Overt Orienting

PubMed Central

Tas, A. Caglar; Luck, Steven J.; Hollingworth, Andrew

2016-01-01

There is substantial debate over whether visual working memory (VWM) and visual attention constitute a single system for the selection of task-relevant perceptual information or whether they are distinct systems that can be dissociated when their representational demands diverge. In the present study, we focused on the relationship between visual attention and the encoding of objects into visual working memory (VWM). Participants performed a color change-detection task. During the retention interval, a secondary object, irrelevant to the memory task, was presented. Participants were instructed either to execute an overt shift of gaze to this object (Experiments 1–3) or to attend it covertly (Experiments 4 and 5). Our goal was to determine whether these overt and covert shifts of attention disrupted the information held in VWM. We hypothesized that saccades, which typically introduce a memorial demand to bridge perceptual disruption, would lead to automatic encoding of the secondary object. However, purely covert shifts of attention, which introduce no such demand, would not result in automatic memory encoding. The results supported these predictions. Saccades to the secondary object produced substantial interference with VWM performance, but covert shifts of attention to this object produced no interference with VWM performance. These results challenge prevailing theories that consider attention and VWM to reflect a common mechanism. In addition, they indicate that the relationship between attention and VWM is dependent on the memorial demands of the orienting behavior. PMID:26854532

I saw where you have been--The topography of human demonstration affects dogs' search patterns and perseverative errors.

PubMed

Péter, András; Topál, József; Miklósi, Ádám; Pongrácz, Péter

2016-04-01

Performance in object search tasks is not only influenced by the subjects' object permanence ability. For example, ostensive cues of the human manipulating the target markedly affect dogs' choices. However, the interference between the target's location and the spatial cues of the human hiding the object is still unknown. In a five-location visible displacement task, the experimental groups differed in the hiding route of the experimenter. In the 'direct' condition he moved straight towards the actual location, hid the object and returned to the dog. In the 'indirect' conditions, he additionally walked behind each screen before returning. The two 'indirect' conditions differed from each other in that the human either visited the previously baited locations before (proactive interference) or after (retroactive interference) hiding the object. In the 'indirect' groups, dogs' performance was significantly lower than in the 'direct' group, demonstrating that for dogs, in an ostensive context, spatial cues of the hider are as important as the observed location of the target. Based on their incorrect choices, dogs were most attracted to the previously baited locations that the human visited after hiding the object in the actual trial. This underlines the importance of retroactive interference in multiple choice tasks. Copyright © 2016 Elsevier B.V. All rights reserved.

Remember to do: insomnia versus control groups in a prospective memory task.

PubMed

Fabbri, Marco; Tonetti, Lorenzo; Martoni, Monica; Natale, Vincenzo

2015-01-01

Primary insomnia is characterized by difficulty in falling asleep and/or remaining asleep, by early morning awakening and/or nonrestorative sleep, and resultant daytime dysfunction in the absence of specific physical, mental, or substance-related causes. However, the studies on daytime cognitive functioning of insomnia patients report inconclusive results. This retrospective study aimed to compare the performance of insomnia patients (N = 54) to that of controls (N = 113) in a naturalistic prospective memory task. Task performance was defined by the percentage of times the event-marker button of an actigraph was pressed, at lights-off time and at wake-up time. The performance pattern in the prospective memory task was similar in both groups. In addition, the task was performed better at lights-off time than at wake-up time regardless of group. Post-hoc subgroup analysis showed that there were more insomnia patients who performed the task perfectly (i.e., 100%) than controls. Performance at wake-up time was significantly correlated to objective sleep quality (i.e., sleep efficiency) only in insomnia patients.

Hippocampus, perirhinal cortex, and complex visual discriminations in rats and humans

PubMed Central

Hales, Jena B.; Broadbent, Nicola J.; Velu, Priya D.

2015-01-01

Structures in the medial temporal lobe, including the hippocampus and perirhinal cortex, are known to be essential for the formation of long-term memory. Recent animal and human studies have investigated whether perirhinal cortex might also be important for visual perception. In our study, using a simultaneous oddity discrimination task, rats with perirhinal lesions were impaired and did not exhibit the normal preference for exploring the odd object. Notably, rats with hippocampal lesions exhibited the same impairment. Thus, the deficit is unlikely to illuminate functions attributed specifically to perirhinal cortex. Both lesion groups were able to acquire visual discriminations involving the same objects used in the oddity task. Patients with hippocampal damage or larger medial temporal lobe lesions were intact in a similar oddity task that allowed participants to explore objects quickly using eye movements. We suggest that humans were able to rely on an intact working memory capacity to perform this task, whereas rats (who moved slowly among the objects) needed to rely on long-term memory. PMID:25593294

Different Effects of Adding White Noise on Cognitive Performance of Sub-, Normal and Super-Attentive School Children

PubMed Central

Helps, Suzannah K.; Bamford, Susan; Sonuga-Barke, Edmund J. S.; Söderlund, Göran B. W.

2014-01-01

Objectives Noise often has detrimental effects on performance. However, because of the phenomenon of stochastic resonance (SR), auditory white noise (WN) can alter the “signal to noise” ratio and improve performance. The Moderate Brain Arousal (MBA) model postulates different levels of internal “neural noise” in individuals with different attentional capacities. This in turn determines the particular WN level most beneficial in each individual case–with one level of WN facilitating poor attenders but hindering super-attentive children. The objective of the present study is to find out if added WN affects cognitive performance differently in children that differ in attention ability. Methods Participants were teacher-rated super- (N = 25); normal- (N = 29) and sub-attentive (N = 36) children (aged 8 to 10 years). Two non-executive function (EF) tasks (a verbal episodic recall task and a delayed verbal recognition task) and two EF tasks (a visuo-spatial working memory test and a Go-NoGo task) were performed under three WN levels. The non-WN condition was only used to control for potential differences in background noise in the group testing situations. Results There were different effects of WN on performance in the three groups-adding moderate WN worsened the performance of super-attentive children for both task types and improved EF performance in sub-attentive children. The normal-attentive children’s performance was unaffected by WN exposure. The shift from moderate to high levels of WN had little further effect on performance in any group. Significance The predicted differential effect of WN on performance was confirmed. However, the failure to find evidence for an inverted U function challenges current theories. Alternative explanations are discussed. We propose that WN therapy should be further investigated as a possible non-pharmacological treatment for inattention. PMID:25393410

Computer task performance by subjects with Duchenne muscular dystrophy.

PubMed

Malheiros, Silvia Regina Pinheiro; da Silva, Talita Dias; Favero, Francis Meire; de Abreu, Luiz Carlos; Fregni, Felipe; Ribeiro, Denise Cardoso; de Mello Monteiro, Carlos Bandeira

2016-01-01

Two specific objectives were established to quantify computer task performance among people with Duchenne muscular dystrophy (DMD). First, we compared simple computational task performance between subjects with DMD and age-matched typically developing (TD) subjects. Second, we examined correlations between the ability of subjects with DMD to learn the computational task and their motor functionality, age, and initial task performance. The study included 84 individuals (42 with DMD, mean age of 18±5.5 years, and 42 age-matched controls). They executed a computer maze task; all participants performed the acquisition (20 attempts) and retention (five attempts) phases, repeating the same maze. A different maze was used to verify transfer performance (five attempts). The Motor Function Measure Scale was applied, and the results were compared with maze task performance. In the acquisition phase, a significant decrease was found in movement time (MT) between the first and last acquisition block, but only for the DMD group. For the DMD group, MT during transfer was shorter than during the first acquisition block, indicating improvement from the first acquisition block to transfer. In addition, the TD group showed shorter MT than the DMD group across the study. DMD participants improved their performance after practicing a computational task; however, the difference in MT was present in all attempts among DMD and control subjects. Computational task improvement was positively influenced by the initial performance of individuals with DMD. In turn, the initial performance was influenced by their distal functionality but not their age or overall functionality.

Categorization is modulated by transcranial direct current stimulation over left prefrontal cortex.

PubMed

Lupyan, Gary; Mirman, Daniel; Hamilton, Roy; Thompson-Schill, Sharon L

2012-07-01

Humans have an unparalleled ability to represent objects as members of multiple categories. A given object, such as a pillow may be-depending on current task demands-represented as an instance of something that is soft, as something that contains feathers, as something that is found in bedrooms, or something that is larger than a toaster. This type of processing requires the individual to dynamically highlight task-relevant properties and abstract over or suppress object properties that, although salient, are not relevant to the task at hand. Neuroimaging and neuropsychological evidence suggests that this ability may depend on cognitive control processes associated with the left inferior prefrontal gyrus. Here, we show that stimulating the left inferior frontal cortex using transcranial direct current stimulation alters performance of healthy subjects on a simple categorization task. Our task required subjects to select pictures matching a description, e.g., "click on all the round things." Cathodal stimulation led to poorer performance on classification trials requiring attention to specific dimensions such as color or shape as opposed to trials that required selecting items belonging to a more thematic category such as objects that hold water. A polarity reversal (anodal stimulation) lowered the threshold for selecting items that were more weakly associated with the target category. These results illustrate the role of frontally-mediated control processes in categorization and suggest potential interactions between categorization, cognitive control, and language. Copyright © 2012 Elsevier B.V. All rights reserved.

Categorization is modulated by transcranical direct current stimulation over left prefrontal cortex

PubMed Central

Lupyan, Gary; Mirman, Daniel; Hamilton, Roy; Thompson-Schill, Sharon L.

2013-01-01

Humans have an unparalleled ability to represent objects as members of multiple categories. A given object, such as a pillow may be—depending on current task demands—represented as an instance of something that is soft, as something that contains feathers, as something that is found in bedrooms, or something that is larger than a toaster. This type of processing requires the individual to dynamically highlight task-relevant properties and abstract over or suppress object properties that, although salient, are not relevant to the task at hand. Neuroimaging and neuropsychological evidence suggests that this ability may depend on cognitive control processes associated with the left inferior prefrontal gyrus. Here, we show that stimulating the left inferior frontal cortex using transcranial direct current stimulation alters performance of healthy subjects on a simple categorization task. Our task required subjects to select pictures matching a description, e.g., “click on all the round things.“ Cathodal stimulation led to poorer performance on classification trials requiring attention to specific dimensions such as color or shape as opposed to trials that required selecting items belonging to a more thematic category such as objects that hold water. A polarity reversal (anodal stimulation) lowered the threshold for selecting items that were more weakly associated with the target category. These results illustrate the role of frontally-mediated control processes in categorization and suggest potential interactions between categorization, cognitive control, and language. PMID:22578885

NEEMO 14: Evaluation of Human Performance for Rover, Cargo Lander, Crew Lander, and Exploration Tasks in Simulated Partial Gravity

NASA Technical Reports Server (NTRS)

Chappell, Steven P.; Abercromby, Andrew F.; Gernhardt, Michael L.

2011-01-01

The ultimate success of future human space exploration missions is dependent on the ability to perform extravehicular activity (EVA) tasks effectively, efficiently, and safely, whether those tasks represent a nominal mode of operation or a contingency capability. To optimize EVA systems for the best human performance, it is critical to study the effects of varying key factors such as suit center of gravity (CG), suit mass, and gravity level. During the 2-week NASA Extreme Environment Mission Operations (NEEMO) 14 mission, four crewmembers performed a series of EVA tasks under different simulated EVA suit configurations and used full-scale mockups of a Space Exploration Vehicle (SEV) rover and lander. NEEMO is an underwater spaceflight analog that allows a true mission-like operational environment and uses buoyancy effects and added weight to simulate different gravity levels. Quantitative and qualitative data collected during NEEMO 14, as well as from spacesuit tests in parabolic flight and with overhead suspension, are being used to directly inform ongoing hardware and operations concept development of the SEV, exploration EVA systems, and future EVA suits. OBJECTIVE: To compare human performance across different weight and CG configurations. METHODS: Four subjects were weighed out to simulate reduced gravity and wore either a specially designed rig to allow adjustment of CG or a PLSS mockup. Subjects completed tasks including level ambulation, incline/decline ambulation, standing from the kneeling and prone position, picking up objects, shoveling, ladder climbing, incapacitated crewmember handling, and small and large payload transfer. Subjective compensation, exertion, task acceptability, and duration data as well as photo and video were collected. RESULTS: There appear to be interactions between CG, weight, and task. CGs nearest the subject s natural CG are the most predictable in terms of acceptable performance across tasks. Future research should focus on understanding the interactions between CG, mass, and subject differences.

The effects of perceptual priming on 4-year-olds' haptic-to-visual cross-modal transfer.

PubMed

Kalagher, Hilary

2013-01-01

Four-year-old children often have difficulty visually recognizing objects that were previously experienced only haptically. This experiment attempts to improve their performance in these haptic-to-visual transfer tasks. Sixty-two 4-year-old children participated in priming trials in which they explored eight unfamiliar objects visually, haptically, or visually and haptically together. Subsequently, all children participated in the same haptic-to-visual cross-modal transfer task. In this task, children haptically explored the objects that were presented in the priming phase and then visually identified a match from among three test objects, each matching the object on only one dimension (shape, texture, or color). Children in all priming conditions predominantly made shape-based matches; however, the most shape-based matches were made in the Visual and Haptic condition. All kinds of priming provided the necessary memory traces upon which subsequent haptic exploration could build a strong enough representation to enable subsequent visual recognition. Haptic exploration patterns during the cross-modal transfer task are discussed and the detailed analyses provide a unique contribution to our understanding of the development of haptic exploratory procedures.

Performance Evaluation of a Mobile Touchscreen Interface for Assistive Robotic Manipulators: A Pilot Study.

PubMed

Chung, Cheng-Shiu; Ka, Hyun W; Wang, Hongu; Ding, Dan; Kelleher, Annmarie; Cooper, Rory A

2017-01-01

Background: Assistive robotic manipulators (ARMs) have been developed to provide enhanced assistance and independence in performance of daily activities among people with spinal cord injury when a caregiver is not on site. However, the current commercial ARM user interfaces (UIs) may be difficult to learn and control. A touchscreen mobile UI was developed to overcome these challenges. Objective: The object of this study was to evaluate the performance between 2 ARM UIs, touchscreen and the original joystick, using an ARM evaluation tool (ARMET). Methods: This is a pilot study of people with upper extremity impairments ( N = 8). Participants were trained on 2 UIs, and then they chose one to use when performing 3 tasks on the ARMET: flipping a toggle switch, pushing down a door handle, and turning a knob. Task completion time, mean velocity, and open interviews were the main outcome measurements. Results: Among 8 novice participants, 7 chose the touchscreen UI and 1 chose the joystick UI. All participants could complete the ARMET tasks independently. Use of the touchscreen UI resulted in enhanced ARMET performance (higher mean moving speed and faster task completion). Conclusions: Mobile ARM UIs demonstrated easier learning experience, less physical effort, and better ARMET performance. The improved performance, the accessibility, and lower physical effort suggested that the touchscreen UI might be an efficient tool for the ARM users.

Soft-light overhead illumination systems improve laparoscopic task performance.

PubMed

Takai, Akihiro; Takada, Yasutsugu; Motomura, Hideki; Teramukai, Satoshi

2014-02-01

The aim of this study was to evaluate the impact of attached shadow cues for laparoscopic task performance. We developed a soft-light overhead illumination system (SOIS) that produced attached shadows on objects. We compared results using the SOIS with those using a conventional illumination system with regard to laparoscopic experience and laparoscope-to-target distances (LTDs). Forty-two medical students and 23 surgeons participated in the study. A peg transfer task (LTD, 120 mm) for students and surgeons, and a suture removal task (LTD, 30 mm) for students were performed. Illumination systems were randomly assigned to each task. Endpoints were: total number of peg transfers; percentage of peg-dropping errors; and total execution time for suture removal. After the task, participants filled out a questionnaire on their preference for a particular illumination system. Total number of peg transfers was greater with the SOIS for both students and surgeons. Percentage of peg-dropping errors for surgeons was lower with the SOIS. Total execution time for suture removal was shorter with the SOIS. Forty-five participants (69% in total) evaluated the SOIS for easier task performance. The present results confirm that the SOIS improves laparoscopic task performance, regardless of previous laparoscopic experience or LTD.

Sleep Deprivation and Time-on-Task Performance Decrement in the Rat Psychomotor Vigilance Task

PubMed Central

Oonk, Marcella; Davis, Christopher J.; Krueger, James M.; Wisor, Jonathan P.; Van Dongen, Hans P.A.

2015-01-01

Study Objectives: The rat psychomotor vigilance task (rPVT) was developed as a rodent analog of the human psychomotor vigilance task (hPVT). We examined whether rPVT performance displays time-on-task effects similar to those observed on the hPVT. Design: The rPVT requires rats to respond to a randomly presented light stimulus to obtain a water reward. Rats were water deprived for 22 h prior to each 30-min rPVT session to motivate performance. We analyzed rPVT performance over time on task and as a function of the response-stimulus interval, at baseline and after sleep deprivation. Setting: The study was conducted in an academic research vivarium. Participants: Male Long-Evans rats were trained to respond to a 0.5 sec stimulus light within 3 sec of stimulus onset. Complete data were available for n = 20 rats. Interventions: Rats performed the rPVT for 30 min at baseline and after 24 h total sleep deprivation by gentle handling. Measurements and Results: Compared to baseline, sleep deprived rats displayed increased performance lapses and premature responses, similar to hPVT lapses of attention and false starts. However, in contrast to hPVT performance, the time-on-task performance decrement was not significantly enhanced by sleep deprivation. Moreover, following sleep deprivation, rPVT response times were not consistently increased after short response-stimulus intervals. Conclusions: The rat psychomotor vigilance task manifests similarities to the human psychomotor vigilance task in global performance outcomes, but not in post-sleep deprivation effects of time on task and response-stimulus interval. Citation: Oonk M, Davis CJ, Krueger JM, Wisor JP, Van Dongen HPA. Sleep deprivation and time-on-task performance decrement in the rat psychomotor vigilance task. SLEEP 2015;38(3):445–451. PMID:25515099

Evaluation of a conceptual framework for predicting navigation performance in virtual reality.

PubMed

Grübel, Jascha; Thrash, Tyler; Hölscher, Christoph; Schinazi, Victor R

2017-01-01

Previous research in spatial cognition has often relied on simple spatial tasks in static environments in order to draw inferences regarding navigation performance. These tasks are typically divided into categories (e.g., egocentric or allocentric) that reflect different two-systems theories. Unfortunately, this two-systems approach has been insufficient for reliably predicting navigation performance in virtual reality (VR). In the present experiment, participants were asked to learn and navigate towards goal locations in a virtual city and then perform eight simple spatial tasks in a separate environment. These eight tasks were organised along four orthogonal dimensions (static/dynamic, perceived/remembered, egocentric/allocentric, and distance/direction). We employed confirmatory and exploratory analyses in order to assess the relationship between navigation performance and performances on these simple tasks. We provide evidence that a dynamic task (i.e., intercepting a moving object) is capable of predicting navigation performance in a familiar virtual environment better than several categories of static tasks. These results have important implications for studies on navigation in VR that tend to over-emphasise the role of spatial memory. Given that our dynamic tasks required efficient interaction with the human interface device (HID), they were more closely aligned with the perceptuomotor processes associated with locomotion than wayfinding. In the future, researchers should consider training participants on HIDs using a dynamic task prior to conducting a navigation experiment. Performances on dynamic tasks should also be assessed in order to avoid confounding skill with an HID and spatial knowledge acquisition.

Evaluation of a conceptual framework for predicting navigation performance in virtual reality

PubMed Central

Thrash, Tyler; Hölscher, Christoph; Schinazi, Victor R.

2017-01-01

Previous research in spatial cognition has often relied on simple spatial tasks in static environments in order to draw inferences regarding navigation performance. These tasks are typically divided into categories (e.g., egocentric or allocentric) that reflect different two-systems theories. Unfortunately, this two-systems approach has been insufficient for reliably predicting navigation performance in virtual reality (VR). In the present experiment, participants were asked to learn and navigate towards goal locations in a virtual city and then perform eight simple spatial tasks in a separate environment. These eight tasks were organised along four orthogonal dimensions (static/dynamic, perceived/remembered, egocentric/allocentric, and distance/direction). We employed confirmatory and exploratory analyses in order to assess the relationship between navigation performance and performances on these simple tasks. We provide evidence that a dynamic task (i.e., intercepting a moving object) is capable of predicting navigation performance in a familiar virtual environment better than several categories of static tasks. These results have important implications for studies on navigation in VR that tend to over-emphasise the role of spatial memory. Given that our dynamic tasks required efficient interaction with the human interface device (HID), they were more closely aligned with the perceptuomotor processes associated with locomotion than wayfinding. In the future, researchers should consider training participants on HIDs using a dynamic task prior to conducting a navigation experiment. Performances on dynamic tasks should also be assessed in order to avoid confounding skill with an HID and spatial knowledge acquisition. PMID:28915266

Handedness results from Complementary Hemispheric Dominance, not Global Hemispheric Dominance: Evidence from Mechanically Coupled Bilateral Movements.

PubMed

Woytowicz, Elizabeth J; Westlake, Kelly P; Whitall, Jill; Sainburg, Robert L

2018-05-09

Two contrasting views of handedness can be described as 1) complementary dominance, in which each hemisphere is specialized for different aspects of motor control, and 2) global dominance, in which the hemisphere contralateral to the dominant arm is specialized for all aspects of motor control. The present study sought to determine which motor lateralization hypothesis best predicts motor performance during common bilateral task of stabilizing an object (e.g. bread) with one hand while applying forces to the object (e.g. slicing) using the other hand. We designed an experimental equivalent of this task, performed in a virtual environment with the unseen arms supported by frictionless air-sleds. The hands were connected by a spring, and the task was to maintain the position of one hand, while moving the other hand to a target. Thus, the reaching hand was required to take account of the spring load to make smooth and accurate trajectories, while the stabilizer hand was required to impede the spring load to keep a constant position. Right-handed subjects performed two task sessions (right hand reach and left hand stabilize; left hand reach and right hand stabilize) with the order of the sessions counterbalanced between groups. Our results indicate a hand by task-component interaction, such that the right hand showed straighter reaching performance while the left showed more stable holding performance. These findings provide support for the complementary dominance hypothesis and suggest that the specializations of each cerebral hemisphere for impedance and dynamic control mechanisms are expressed during bilateral interactive tasks.

Design and testing of a functional arm orthosis in patients with neuromuscular diseases.

PubMed

Rahman, Tariq; Sample, Whitney; Seliktar, Rahamim; Scavina, Mena T; Clark, Alisa L; Moran, Kacy; Alexander, Michael A

2007-06-01

The objective of this study was to determine the utility of a passive gravity-balanced arm orthosis, the Wilmington robotic exoskeleton (WREX), for patients with neuromuscular diseases. The WREX, a four-degrees-of-freedom functional orthosis, is energized by rubber bands to eliminate gravity and is attached to the wheelchair. The development and clinical testing of WREX is described in this report. Seventeen patients (14 boys and 3 girls) with muscular disabilities participated in the study. Ages ranged from 4 to 20 years. Criteria for inclusion included a weakened arm, use of a wheelchair, the ability to grasp and release objects, and the ability to provide feedback on device use. Testing consisted of administering the Jebsen test of hand function without WREX and then testing again after approximately two weeks of wearing the WREX orthosis. The timed results of each task within the test then were compared. Specific tasks related to vertical movement required less time to perform with the WREX. A large number of subjects were able to perform the Jebsen tasks with the WREX, where they were unable to perform the task without the WREX. Patients can benefit from WREX because it increases their performance in daily living activities and makes many tasks possible. The range-of-motion in the patients' arms increased considerably, while the time required to complete some of the Jebsen test tasks decreased. Most patients were very receptive to WREX, although a few were ambivalent.

Impairment in judgement of the moral emotion guilt following orbitofrontal cortex damage.

PubMed

Funayama, Michitaka; Koreki, Akihiro; Muramatsu, Taro; Mimura, Masaru; Kato, Motoichiro; Abe, Takayuki

2018-04-19

Although neuroimaging studies have provided evidence for an association between moral emotions and the orbitofrontal cortex, studies on patients with focal lesions using experimental probes of moral emotions are scarce. Here, we addressed this topic by presenting a moral emotion judgement task to patients with focal brain damage. Four judgement tasks in a simple pairwise choice paradigm were given to 72 patients with cerebrovascular disease. These tasks consisted of a perceptual line judgement task as a control task; the objects' preference task as a basic preference judgement task; and two types of moral emotion judgement task, an anger task and a guilt task. A multiple linear regression analysis was performed on each set of task performance scores to take into account potential confounders. Performance on the guilt emotion judgement task negatively correlated with the orbitofrontal cortex damage, but not with the other variables. Results for the other judgement tasks did not reach statistical significance. The close association between orbitofrontal cortex damage and a decrease in guilt emotion judgement consistency might suggest that the orbitofrontal cortex plays a key role in the sense of guilt, a hallmark of morality. © 2018 The British Psychological Society.

Interactive Tools for Measuring Visual Scanning Performance and Reaction Time

PubMed Central

Seeanner, Julia; Hennessy, Sarah; Manganelli, Joseph; Crisler, Matthew; Rosopa, Patrick; Jenkins, Casey; Anderson, Michael; Drouin, Nathalie; Belle, Leah; Truesdail, Constance; Tanner, Stephanie

2017-01-01

Occupational therapists are constantly searching for engaging, high-technology interactive tasks that provide immediate feedback to evaluate and train clients with visual scanning deficits. This study examined the relationship between two tools: the VISION COACH™ interactive light board and the Functional Object Detection© (FOD) Advanced driving simulator scenario. Fifty-four healthy drivers, ages 21–66 yr, were divided into three age groups. Participants performed braking response and visual target (E) detection tasks of the FOD Advanced driving scenario, followed by two sets of three trials using the VISION COACH Full Field 60 task. Results showed no significant effect of age on FOD Advanced performance but a significant effect of age on VISION COACH performance. Correlations showed that participants’ performance on both braking and E detection tasks were significantly positively correlated with performance on the VISION COACH (.37 < r < .40, p < .01). These tools provide new options for therapists. PMID:28218598

Performance of four different rat strains in the autoshaping, two-object discrimination, and swim maze tests of learning and memory.

PubMed

Andrews, J S; Jansen, J H; Linders, S; Princen, A; Broekkamp, C L

1995-04-01

The performance of four strains of rats commonly used in behavioural research was assessed in three different tests of learning and memory. The four strains included three outbred lines (Long-Evans, Sprague-Dawley, Wistar) and one inbred strain (S3). Learning and memory were tested using three different paradigms: autoshaping of a lever press, a two-object discrimination test, and performance in a two-island swim maze task. The pigmented strains showed better performance in the autoshaping procedure: the majority of the Long-Evans and the S3 rats acquired the response, and the majority of the Wistar and Sprague-Dawley failed to acquire the response in the set time. The albino strains were slightly better in the swim maze than the pigmented strains. There appeared to be a speed/accuracy trade-off in the strategy used to solve the task. This was also evident following treatment with the cholinergic-depleting agent hemicholinium-3. The performance of the Long-Evans rats was most affected by the treatment in terms of accuracy and the Wistar and Sprague-Dawleys in terms of speed. In the two-object discrimination test only the Long-Evans showed satisfactory performance and were able to discriminate a novel from a known object a short interval after initial exposure. These results show large task- and strain-dependent differences in performance in tests of learning and memory. Some of the performance variation may be due to emotional differences between the strains and may be alleviated by extra training. However, the response to pharmacological manipulation may require more careful evaluation.(ABSTRACT TRUNCATED AT 250 WORDS)

Effect of feedback mode and task difficulty on quality of timing decisions in a zero-sum game.

PubMed

Tikuisis, Peter; Vartanian, Oshin; Mandel, David R

2014-09-01

The objective was to investigate the interaction between the mode of performance outcome feedback and task difficulty on timing decisions (i.e., when to act). Feedback is widely acknowledged to affect task performance. However, the extent to which feedback display mode and its impact on timing decisions is moderated by task difficulty remains largely unknown. Participants repeatedly engaged a zero-sum game involving silent duels with a computerized opponent and were given visual performance feedback after each engagement. They were sequentially tested on three different levels of task difficulty (low, intermediate, and high) in counterbalanced order. Half received relatively simple "inside view" binary outcome feedback, and the other half received complex "outside view" hit rate probability feedback. The key dependent variables were response time (i.e., time taken to make a decision) and survival outcome. When task difficulty was low to moderate, participants were more likely to learn and perform better from hit rate probability feedback than binary outcome feedback. However, better performance with hit rate feedback exacted a higher cognitive cost manifested by higher decision response time. The beneficial effect of hit rate probability feedback on timing decisions is partially moderated by task difficulty. Performance feedback mode should be judiciously chosen in relation to task difficulty for optimal performance in tasks involving timing decisions.

Self-motion impairs multiple-object tracking.

PubMed

Thomas, Laura E; Seiffert, Adriane E

2010-10-01

Investigations of multiple-object tracking aim to further our understanding of how people perform common activities such as driving in traffic. However, tracking tasks in the laboratory have overlooked a crucial component of much real-world object tracking: self-motion. We investigated the hypothesis that keeping track of one's own movement impairs the ability to keep track of other moving objects. Participants attempted to track multiple targets while either moving around the tracking area or remaining in a fixed location. Participants' tracking performance was impaired when they moved to a new location during tracking, even when they were passively moved and when they did not see a shift in viewpoint. Self-motion impaired multiple-object tracking in both an immersive virtual environment and a real-world analog, but did not interfere with a difficult non-spatial tracking task. These results suggest that people use a common mechanism to track changes both to the location of moving objects around them and to keep track of their own location. Copyright 2010 Elsevier B.V. All rights reserved.

Automated Support for da Vinci Surgical System

DTIC Science & Technology

2011-05-01

MScore, which provides objective assessment measuring robotic surgery skills across all computed metrics (Figure 7). In addition to viewing single ...holding an object. Data Collection & Analysis (Task 5)  Preliminary Experiments  During the first phase of data collection, a single performance of...a single task (anastomosis) trial was recorded from six different users – three each for the da Vinci and the dV-Trainer platforms. On each platform

Gaze Following in Children with Autism: Do High Interest Objects Boost Performance?

ERIC Educational Resources Information Center

Thorup, Emilia; Kleberg, Johan Lundin; Falck-Ytter, Terje

2017-01-01

This study tested whether including objects perceived as highly interesting by children with autism during a gaze following task would result in increased first fixation durations on the target objects. It has previously been found that autistic children differentiate less between an object another person attends to and unattended objects in terms…

Application of objective clinical human reliability analysis (OCHRA) in assessment of technical performance in laparoscopic rectal cancer surgery.

PubMed

Foster, J D; Miskovic, D; Allison, A S; Conti, J A; Ockrim, J; Cooper, E J; Hanna, G B; Francis, N K

2016-06-01

Laparoscopic rectal resection is technically challenging, with outcomes dependent upon technical performance. No robust objective assessment tool exists for laparoscopic rectal resection surgery. This study aimed to investigate the application of the objective clinical human reliability analysis (OCHRA) technique for assessing technical performance of laparoscopic rectal surgery and explore the validity and reliability of this technique. Laparoscopic rectal cancer resection operations were described in the format of a hierarchical task analysis. Potential technical errors were defined. The OCHRA technique was used to identify technical errors enacted in videos of twenty consecutive laparoscopic rectal cancer resection operations from a single site. The procedural task, spatial location, and circumstances of all identified errors were logged. Clinical validity was assessed through correlation with clinical outcomes; reliability was assessed by test-retest. A total of 335 execution errors identified, with a median 15 per operation. More errors were observed during pelvic tasks compared with abdominal tasks (p < 0.001). Within the pelvis, more errors were observed during dissection on the right side than the left (p = 0.03). Test-retest confirmed reliability (r = 0.97, p < 0.001). A significant correlation was observed between error frequency and mesorectal specimen quality (r s = 0.52, p = 0.02) and with blood loss (r s = 0.609, p = 0.004). OCHRA offers a valid and reliable method for evaluating technical performance of laparoscopic rectal surgery.

Dual tasking negatively impacts obstacle avoidance abilities in post-stroke individuals with visuospatial neglect: Task complexity matters!

PubMed

Aravind, Gayatri; Lamontagne, Anouk

2017-01-01

Persons with perceptual-attentional deficits due to visuospatial neglect (VSN) after a stroke are at a risk of collisions while walking in the presence of moving obstacles. The attentional burden of performing a dual-task may further compromise their obstacle avoidance performance, putting them at a greater risk of collisions. The objective of this study was to compare the ability of persons with (VSN+) and without VSN (VSN-) to dual task while negotiating moving obstacles. Twenty-six stroke survivors (13 VSN+, 13 VSN-) were assessed on their ability to (a) negotiate moving obstacles while walking (locomotor single task); (b) perform a pitch-discrimination task (cognitive single task) and (c) simultaneously perform the walking and cognitive tasks (dual task). We compared the groups on locomotor (collision rates, minimum distance from obstacle and onset of strategies) and cognitive (error rates) outcomes. For both single and dual task walking, VSN+ individuals showed higher collision rates compared to VSN- individuals. Dual tasking caused deterioration of locomotor (more collisions, delayed onset and smaller minimum distances) and cognitive performances (higher error rate) in VSN+ individuals. Contrastingly, VSN- individuals maintained collision rates, increased minimum distance, but showed more cognitive errors, prioritizing their locomotor performance. Individuals with VSN demonstrate cognitive-locomotor interference under dual task conditions, which could severely compromise safety when ambulating in community environments and may explain the poor recovery of independent community ambulation in these individuals.

The Effect of Two-dimensional and Stereoscopic Presentation on Middle School Students' Performance of Spatial Cognition Tasks

NASA Astrophysics Data System (ADS)

Price, Aaron; Lee, Hee-Sun

2010-02-01

We investigated whether and how student performance on three types of spatial cognition tasks differs when worked with two-dimensional or stereoscopic representations. We recruited nineteen middle school students visiting a planetarium in a large Midwestern American city and analyzed their performance on a series of spatial cognition tasks in terms of response accuracy and task completion time. Results show that response accuracy did not differ between the two types of representations while task completion time was significantly greater with the stereoscopic representations. The completion time increased as the number of mental manipulations of 3D objects increased in the tasks. Post-interviews provide evidence that some students continued to think of stereoscopic representations as two-dimensional. Based on cognitive load and cue theories, we interpret that, in the absence of pictorial depth cues, students may need more time to be familiar with stereoscopic representations for optimal performance. In light of these results, we discuss potential uses of stereoscopic representations for science learning.

Cerebral mechanisms underlying the effects of music during a fatiguing isometric ankle-dorsiflexion task.

PubMed

Bigliassi, Marcelo; Karageorghis, Costas I; Nowicky, Alexander V; Orgs, Guido; Wright, Michael J

2016-10-01

The brain mechanisms by which music-related interventions ameliorate fatigue-related symptoms during the execution of fatiguing motor tasks are hitherto under-researched. The objective of the present study was to investigate the effects of music on brain electrical activity and psychophysiological measures during the execution of an isometric fatiguing ankle-dorsiflexion task performed until the point of volitional exhaustion. Nineteen healthy participants performed two fatigue tests at 40% of maximal voluntary contraction while listening to music or in silence. Electrical activity in the brain was assessed by use of a 64-channel EEG. The results indicated that music downregulated theta waves in the frontal, central, and parietal regions of the brain during exercise. Music also induced a partial attentional switching from associative thoughts to task-unrelated factors (dissociative thoughts) during exercise, which led to improvements in task performance. Moreover, participants experienced a more positive affective state while performing the isometric task under the influence of music. © 2016 Society for Psychophysiological Research.

In-Vehicle Display Icons and Other Information Elements: Literature Review

DOT National Transportation Integrated Search

1998-05-01

This report describes the objectives, methods, and findings associated with Task A: Perform Literature Review. The purpose of Task A is to conduct a review of relevant symbols and research, including the use of symbols by manufacturers and after-mark...

The contributions of visual and central attention to visual working memory.

PubMed

Souza, Alessandra S; Oberauer, Klaus

2017-10-01

We investigated the role of two kinds of attention-visual and central attention-for the maintenance of visual representations in working memory (WM). In Experiment 1 we directed attention to individual items in WM by presenting cues during the retention interval of a continuous delayed-estimation task, and instructing participants to think of the cued items. Attending to items improved recall commensurate with the frequency with which items were attended (0, 1, or 2 times). Experiments 1 and 3 further tested which kind of attention-visual or central-was involved in WM maintenance. We assessed the dual-task costs of two types of distractor tasks, one tapping sustained visual attention and one tapping central attention. Only the central attention task yielded substantial dual-task costs, implying that central attention substantially contributes to maintenance of visual information in WM. Experiment 2 confirmed that the visual-attention distractor task was demanding enough to disrupt performance in a task relying on visual attention. We combined the visual-attention and the central-attention distractor tasks with a multiple object tracking (MOT) task. Distracting visual attention, but not central attention, impaired MOT performance. Jointly, the three experiments provide a double dissociation between visual and central attention, and between visual WM and visual object tracking: Whereas tracking multiple targets across the visual filed depends on visual attention, visual WM depends mostly on central attention.

Visual long-term memory and change blindness: Different effects of pre- and post-change information on one-shot change detection using meaningless geometric objects.

PubMed

Nishiyama, Megumi; Kawaguchi, Jun

2014-11-01

To clarify the relationship between visual long-term memory (VLTM) and online visual processing, we investigated whether and how VLTM involuntarily affects the performance of a one-shot change detection task using images consisting of six meaningless geometric objects. In the study phase, participants observed pre-change (Experiment 1), post-change (Experiment 2), or both pre- and post-change (Experiment 3) images appearing in the subsequent change detection phase. In the change detection phase, one object always changed between pre- and post-change images and participants reported which object was changed. Results showed that VLTM of pre-change images enhanced the performance of change detection, while that of post-change images decreased accuracy. Prior exposure to both pre- and post-change images did not influence performance. These results indicate that pre-change information plays an important role in change detection, and that information in VLTM related to the current task does not always have a positive effect on performance. Copyright © 2014 Elsevier Inc. All rights reserved.

The interaction of feature and space based orienting within the attention set.

PubMed

Lim, Ahnate; Sinnett, Scott

2014-01-01

The processing of sensory information relies on interacting mechanisms of sustained attention and attentional capture, both of which operate in space and on object features. While evidence indicates that exogenous attentional capture, a mechanism previously understood to be automatic, can be eliminated while concurrently performing a demanding task, we reframe this phenomenon within the theoretical framework of the "attention set" (Most et al., 2005). Consequently, the specific prediction that cuing effects should reappear when feature dimensions of the cue overlap with those in the attention set (i.e., elements of the demanding task) was empirically tested and confirmed using a dual-task paradigm involving both sustained attention and attentional capture, adapted from Santangelo et al. (2007). Participants were required to either detect a centrally presented target presented in a stream of distractors (the primary task), or respond to a spatially cued target (the secondary task). Importantly, the spatial cue could either share features with the target in the centrally presented primary task, or not share any features. Overall, the findings supported the attention set hypothesis showing that a spatial cuing effect was only observed when the peripheral cue shared a feature with objects that were already in the attention set (i.e., the primary task). However, this finding was accompanied by differential attentional orienting dependent on the different types of objects within the attention set, with feature-based orienting occurring for target-related objects, and additional spatial-based orienting for distractor-related objects.

The interaction of feature and space based orienting within the attention set

PubMed Central

Lim, Ahnate; Sinnett, Scott

2014-01-01

The processing of sensory information relies on interacting mechanisms of sustained attention and attentional capture, both of which operate in space and on object features. While evidence indicates that exogenous attentional capture, a mechanism previously understood to be automatic, can be eliminated while concurrently performing a demanding task, we reframe this phenomenon within the theoretical framework of the “attention set” (Most et al., 2005). Consequently, the specific prediction that cuing effects should reappear when feature dimensions of the cue overlap with those in the attention set (i.e., elements of the demanding task) was empirically tested and confirmed using a dual-task paradigm involving both sustained attention and attentional capture, adapted from Santangelo et al. (2007). Participants were required to either detect a centrally presented target presented in a stream of distractors (the primary task), or respond to a spatially cued target (the secondary task). Importantly, the spatial cue could either share features with the target in the centrally presented primary task, or not share any features. Overall, the findings supported the attention set hypothesis showing that a spatial cuing effect was only observed when the peripheral cue shared a feature with objects that were already in the attention set (i.e., the primary task). However, this finding was accompanied by differential attentional orienting dependent on the different types of objects within the attention set, with feature-based orienting occurring for target-related objects, and additional spatial-based orienting for distractor-related objects. PMID:24523682

Progestogens’ effects and mechanisms for object recognition memory across the lifespan

PubMed Central

Walf, Alicia A.; Koonce, Carolyn J.; Frye, Cheryl A.

2016-01-01

This review explores the effects of female reproductive hormones, estrogens and progestogens, with a focus on progesterone and allopregnanolone, on object memory. Progesterone and its metabolites, in particular allopregnanolone, exert various effects on both cognitive and non-mnemonic functions in females. The well-known object recognition task is a valuable experimental paradigm that can be used to determine the effects and mechanisms of progestogens for mnemonic effects across the lifespan, which will be discussed herein. In this task there is little test-decay when different objects are used as targets and baseline valance for objects is controlled. This allows repeated testing, within-subjects designs, and longitudinal assessments, which aid understanding of changes in hormonal milieu. Objects are not aversive or food-based, which are hormone-sensitive factors. This review focuses on published data from our laboratory, and others, using the object recognition task in rodents to assess the role and mechanisms of progestogens throughout the lifespan. Improvements in object recognition performance of rodents are often associated with higher hormone levels in the hippocampus and prefrontal cortex during natural cycles, with hormone replacement following ovariectomy in young animals, or with aging. The capacity for reversal of age- and reproductive senescence-related decline in cognitive performance, and changes in neural plasticity that may be dissociated from peripheral effects with such decline, are discussed. The focus here will be on the effects of brain-derived factors, such as the neurosteroid, allopregnanolone, and other hormones, for enhancing object recognition across the lifespan. PMID:26235328

Measuring beliefs in centimeters: private knowledge biases preschoolers' and adults' representation of others' beliefs.

PubMed

Sommerville, Jessica A; Bernstein, Daniel M; Meltzoff, Andrew N

2013-01-01

A novel task, using a continuous spatial layout, was created to investigate the degree to which (in centimeters) 3-year-old children's (N = 63), 5-year-old children's (N = 60), and adults' (N = 60) own privileged knowledge of the location of an object biased their representation of a protagonist's false belief about the object's location. At all ages, participants' knowledge of the object's actual location biased their search estimates, independent of the attentional or memory demands of the task. Children's degree of bias correlated with their performance on a classic change-of-location false belief task, controlling for age. This task is a novel tool for providing a quantitative measurement of the degree to which self-knowledge can bias estimates of others' beliefs. © 2013 The Authors. Child Development © 2013 Society for Research in Child Development, Inc.

Conditional responding is impaired in chronic alcoholics.

PubMed

Hildebrandt, Helmut; Brokate, B; Hoffmann, E; Kröger, B; Eling, P

2006-07-01

Bechara (2003) describes a model for disturbances in executive functions related to addiction. This model involves deficits in decision-making and in suppressing pre-potent representations or response patterns. We tested this model in 29 individuals with long-term heavy alcohol dependency and compared their performance with that of 20 control subjects. Only individuals without memory impairment, with normal intelligence and normal visual response times were included. We examined word fluency, object alternation, spatial stimulus-response incompatibility, extra-dimensional shift learning and decision-making using the Gambling task. We subtracted the performance in a control condition from that of the executive condition, in order to focus specifically on the executive component of each task. Only the object alternation and incompatibility tasks revealed significant differences between the group of alcoholics and the control group. Moreover, response times in the object alternation task correlated with duration of alcohol dependency. The results do not argue in favor of a specific deficit in decision-making or in shifting between relevant representations. We conclude that long-term alcohol abuse leads to an impairment in conditional responding, provided the response depends on former reactions or the inhibition of pre-potent response patterns.

TASAR Certification and Operational Approval Requirements - Analyses and Results

NASA Technical Reports Server (NTRS)

Koczo, Stefan, Jr.

2015-01-01

This report documents the results of research and development work performed by Rockwell Collins in addressing the Task 1 objectives under NASA Contract NNL12AA11C. Under this contract Rockwell Collins provided analytical support to the NASA Langley Research Center (LaRC) in NASA's development of a Traffic Aware Strategic Aircrew Requests (TASAR) flight deck Electronic Flight Bag (EFB) application for technology transition into operational use. The two primary objectives of this contract were for Rockwell Collins and the University of Iowa OPL to 1) perform an implementation assessment of TASAR toward early certification and operational approval of TASAR as an EFB application (Task 1 of this contract), and 2) design, develop and conduct two Human-in-the-Loop (HITL) simulation experiments that evaluate TASAR and the associated Traffic Aware Planner (TAP) software application to determine the situational awareness and workload impacts of TASAR in the flight deck, while also assessing the level of comprehension, usefulness, and usability of the features of TAP (Task 2 of this contract). This report represents the Task 1 summary report. The Task 2 summary report is provided in [0].

Pathways of the inferior frontal occipital fasciculus in overt speech and reading.

PubMed

Rollans, Claire; Cheema, Kulpreet; Georgiou, George K; Cummine, Jacqueline

2017-11-19

In this study, we examined the relationship between tractography-based measures of white matter integrity (ex. fractional anisotropy [FA]) from diffusion tensor imaging (DTI) and five reading-related tasks, including rapid automatized naming (RAN) of letters, digits, and objects, and reading of real words and nonwords. Twenty university students with no reported history of reading difficulties were tested on all five tasks and their performance was correlated with diffusion measures extracted through DTI tractography. A secondary analysis using whole-brain Tract-Based Spatial Statistics (TBSS) was also used to find clusters showing significant negative correlations between reaction time and FA. Results showed a significant relationship between the left inferior fronto-occipital fasciculus FA and performance on the RAN of objects task, as well as a strong relationship to nonword reading, which suggests a role for this tract in slower, non-automatic and/or resource-demanding speech tasks. There were no significant relationships between FA and the faster, more automatic speech tasks (RAN of letters and digits, and real word reading). These findings provide evidence for the role of the inferior fronto-occipital fasciculus in tasks that are highly demanding of orthography-phonology translation (e.g., nonword reading) and semantic processing (e.g., RAN object). This demonstrates the importance of the inferior fronto-occipital fasciculus in basic naming and suggests that this tract may be a sensitive predictor of rapid naming performance within the typical population. We discuss the findings in the context of current models of reading and speech production to further characterize the white matter pathways associated with basic reading processes. Copyright © 2017 IBRO. Published by Elsevier Ltd. All rights reserved.

Effects of Arm Weight on C-Not-B Task Performance: Implications for the Motor Inhibitory Deficit Account of Search Failures

ERIC Educational Resources Information Center

Riviere, James; Lecuyer, Roger

2008-01-01

Toddlers have been found to fail on a three-location search task involving the invisible displacements of an object, namely the C-not-B task. In this task, a child is shown the experimenter's hand that contains a toy. The toy then successively disappears under the three cloths (A, B, then C). The examiner silently releases the toy under the second…

Human listeners provide insights into echo features used by dolphins (Tursiops truncatus) to discriminate among objects.

PubMed

Delong, Caroline M; Au, Whitlow W L; Harley, Heidi E; Roitblat, Herbert L; Pytka, Lisa

2007-08-01

Echolocating bottlenose dolphins (Tursiops truncatus) discriminate between objects on the basis of the echoes reflected by the objects. However, it is not clear which echo features are important for object discrimination. To gain insight into the salient features, the authors had a dolphin perform a match-to-sample task and then presented human listeners with echoes from the same objects used in the dolphin's task. In 2 experiments, human listeners performed as well or better than the dolphin at discriminating objects, and they reported the salient acoustic cues. The error patterns of the humans and the dolphin were compared to determine which acoustic features were likely to have been used by the dolphin. The results indicate that the dolphin did not appear to use overall echo amplitude, but that it attended to the pattern of changes in the echoes across different object orientations. Human listeners can quickly identify salient combinations of echo features that permit object discrimination, which can be used to generate hypotheses that can be tested using dolphins as subjects.

Object-oriented sequence analysis: SCL--a C++ class library.

PubMed

Vahrson, W; Hermann, K; Kleffe, J; Wittig, B

1996-04-01

SCL (Sequence Class Library) is a class library written in the C++ programming language. Designed using object-oriented programming principles, SCL consists of classes of objects performing tasks typically needed for analyzing DNA or protein sequences. Among them are very flexible sequence classes, classes accessing databases in various formats, classes managing collections of sequences, as well as classes performing higher-level tasks like calculating a pairwise sequence alignment. SCL also includes classes that provide general programming support, like a dynamically growing array, sets, matrices, strings, classes performing file input/output, and utilities for error handling. By providing these components, SCL fosters an explorative programming style: experimenting with algorithms and alternative implementations is encouraged rather than punished. A description of SCL's overall structure as well as an overview of its classes is given. Important aspects of the work with SCL are discussed in the context of a sample program.

Objects predict fixations better than early saliency.

PubMed

Einhäuser, Wolfgang; Spain, Merrielle; Perona, Pietro

2008-11-20

Humans move their eyes while looking at scenes and pictures. Eye movements correlate with shifts in attention and are thought to be a consequence of optimal resource allocation for high-level tasks such as visual recognition. Models of attention, such as "saliency maps," are often built on the assumption that "early" features (color, contrast, orientation, motion, and so forth) drive attention directly. We explore an alternative hypothesis: Observers attend to "interesting" objects. To test this hypothesis, we measure the eye position of human observers while they inspect photographs of common natural scenes. Our observers perform different tasks: artistic evaluation, analysis of content, and search. Immediately after each presentation, our observers are asked to name objects they saw. Weighted with recall frequency, these objects predict fixations in individual images better than early saliency, irrespective of task. Also, saliency combined with object positions predicts which objects are frequently named. This suggests that early saliency has only an indirect effect on attention, acting through recognized objects. Consequently, rather than treating attention as mere preprocessing step for object recognition, models of both need to be integrated.

Brain-computer interface control along instructed paths

NASA Astrophysics Data System (ADS)

Sadtler, P. T.; Ryu, S. I.; Tyler-Kabara, E. C.; Yu, B. M.; Batista, A. P.

2015-02-01

Objective. Brain-computer interfaces (BCIs) are being developed to assist paralyzed people and amputees by translating neural activity into movements of a computer cursor or prosthetic limb. Here we introduce a novel BCI task paradigm, intended to help accelerate improvements to BCI systems. Through this task, we can push the performance limits of BCI systems, we can quantify more accurately how well a BCI system captures the user’s intent, and we can increase the richness of the BCI movement repertoire. Approach. We have implemented an instructed path task, wherein the user must drive a cursor along a visible path. The instructed path task provides a versatile framework to increase the difficulty of the task and thereby push the limits of performance. Relative to traditional point-to-point tasks, the instructed path task allows more thorough analysis of decoding performance and greater richness of movement kinematics. Main results. We demonstrate that monkeys are able to perform the instructed path task in a closed-loop BCI setting. We further investigate how the performance under BCI control compares to native arm control, whether users can decrease their movement variability in the face of a more demanding task, and how the kinematic richness is enhanced in this task. Significance. The use of the instructed path task has the potential to accelerate the development of BCI systems and their clinical translation.

A new paper and pencil task reveals adult false belief reasoning bias.

PubMed

Coburn, Patricia I; Bernstein, Daniel M; Begeer, Sander

2015-09-01

Theory of mind (ToM) is the ability to take other people's perspective by inferring their mental state. Most 6-year olds pass the change-of-location false belief task that is commonly used to assess ToM. However, the change-of-location task is not suitable for individuals over 5 years of age, due to its discrete response options. In two experiments, we used a paper and pencil version of a modified change-of-location task (the Real Object Sandbox task) to assess false belief reasoning continuously rather than discretely in adults. Participants heard nine change-of-location scenarios and answered a critical question after each. The memory control questions only required the participant to remember the object's original location, whereas the false belief questions required participants to take the perspective of the protagonist. Participants were more accurate on memory trials than trials requiring perspective taking, and performance on paper and pencil trials correlated with corresponding trials on the Real Object Sandbox task. The Paper and Pencil Sandbox task is a convenient continuous measure of ToM that could be administered to a wide range of age groups.

Is it a bird? Is it a plane? Ultra-rapid visual categorisation of natural and artifactual objects.

PubMed

VanRullen, R; Thorpe, S J

2001-01-01

Visual processing is known to be very fast in ultra-rapid categorisation tasks where the subject has to decide whether a briefly flashed image belongs to a target category or not. Human subjects can respond in under 400 ms, and event-related-potential studies have shown that the underlying processing can be done in less than 150 ms. Monkeys trained to perform the same task have proved even faster. However, most of these experiments have only been done with biologically relevant target categories such as animals or food. Here we performed the same study on human subjects, alternating between a task in which the target category was 'animal', and a task in which the target category was 'means of transport'. These natural images of clearly artificial objects contained targets as varied as cars, trucks, trains, boats, aircraft, and hot-air balloons. However, the subjects performed almost identically in both tasks, with reaction times not significantly longer in the 'means of transport' task. These reaction times were much shorter than in any previous study on natural-image processing. We conclude that, at least for these two superordinate categories, the speed of ultra-rapid visual categorisation of natural scenes does not depend on the target category, and that this processing could rely primarily on feed-forward, automatic mechanisms.

[Influence of mental rotation of objects on psychophysiological functions of women].

PubMed

Chikina, L V; Fedorchuk, S V; Trushina, V A; Ianchuk, P I; Makarchuk, M Iu

2012-01-01

An integral part of activity of modern human beings is an involvement to work with the computer systems which, in turn, produces a nervous - emotional tension. Hence, a problem of control of the psychophysiological state of workmen with the purpose of health preservation and success of their activity and the problem of application of rehabilitational actions are actual. At present it is known that the efficiency of rehabilitational procedures rises following application of the complex of regenerative programs. Previously performed by us investigation showed that mental rotation is capable to compensate the consequences of a nervous - emotional tension. Therefore, in the present work we investigated how the complex of spatial tasks developed by us influences psychophysiological performances of tested women for which the psycho-emotional tension with the usage of computer technologies is more essential, and the procedure of mental rotation is more complex task for them, than for men. The complex of spatial tasks applied in the given work included: mental rotation of simple objects (letters and digits), mental rotation of complex objects (geometrical figures) and mental rotation of complex objects with the usage of a short-term memory. Execution of the complex of spatial tasks reduces the time of simple and complex sensomotor response, raises parameters of a short-term memory, brain work capacity and improves nervous processes. Collectively, mental rotation of objects can be recommended as a rehabilitational resource for compensation of consequences of any psycho-emotional strain, both for men, and for women.

Place and contingency differential responses of monkey septal neurons during conditional place-object discrimination.

PubMed

Kita, T; Nishijo, H; Eifuku, S; Terasawa, K; Ono, T

1995-03-01

To elucidate spatial and cognitive function of the septal nuclei, neural activity was recorded from alert monkeys during performance of a place-dependent go/no-go (PGN) task. Response/reinforcement contingencies of given objects were conditional upon the location of a motorized, movable device (cab) containing a monkey in one of four places. The task was initiated by presentation of the outside view (place phase) followed by presentation of an object (object phase) selected from a total of four. A lever press was reinforced only if the correct object was seen in its corresponding place, and the same object was never reinforced in any of the other three places. Of 430 septal neurons recorded, the responses during the place phase in the four places were significantly different in 58 neurons. Responses of eight of these neurons were also place-differential during the object phase as well as the place phase. Furthermore, when the outside view was not presented before the object phase, differential responses in the object phase disappeared. Responses of 91 neurons in the object phase were differential in terms of go/no-go responses and reward availability. Of these 91 neurons, 72 were further tested on a place-independent asymmetrical go/no-go (AGN) task, which required no conditional discrimination. Forty-three neurons responded differentially only in the PGN task. It is thus concluded that this PGN-specific activity reflected conditional place-object relations. Of the remaining 29 neurons that responded differentially in both tasks, 21 were further tested by a place-independent symmetrical go/no-go task (no-go responses were also rewarded). Responses of 19 of these 21 neurons were related to the reward/nonreward contingency but not to the response contingency. The results suggest that septal nuclei are involved in integrating spatial information, conditional place-object relations, and reward/nonreward contingency.

Assessment of Joystick control during the performance of powered wheelchair driving tasks

PubMed Central

2011-01-01

Background Powered wheelchairs are essential for many individuals who have mobility impairments. Nevertheless, if operated improperly, the powered wheelchair poses dangers to both the user and to those in its vicinity. Thus, operating a powered wheelchair with some degree of proficiency is important for safety, and measuring driving skills becomes an important issue to address. The objective of this study was to explore the discriminate validity of outcome measures of driving skills based on joystick control strategies and performance recorded using a data logging system. Methods We compared joystick control strategies and performance during standardized driving tasks between a group of 10 expert and 13 novice powered wheelchair users. Driving tasks were drawn from the Wheelchair Skills Test (v. 4.1). Data from the joystick controller were collected on a data logging system. Joystick control strategies and performance outcome measures included the mean number of joystick movements, time required to complete tasks, as well as variability of joystick direction. Results In simpler tasks, the expert group's driving skills were comparable to those of the novice group. Yet, in more difficult and spatially confined tasks, the expert group required fewer joystick movements for task completion. In some cases, experts also completed tasks in approximately half the time with respect to the novice group. Conclusions The analysis of joystick control made it possible to discriminate between novice and expert powered wheelchair users in a variety of driving tasks. These results imply that in spatially confined areas, a greater powered wheelchair driving skill level is required to complete tasks efficiently. Based on these findings, it would appear that the use of joystick signal analysis constitutes an objective tool for the measurement of powered wheelchair driving skills. This tool may be useful for the clinical assessment and training of powered wheelchair skills. PMID:21609435

HLLV avionics requirements study and electronic filing system database development

NASA Technical Reports Server (NTRS)

1994-01-01

This final report provides a summary of achievements and activities performed under Contract NAS8-39215. The contract's objective was to explore a new way of delivering, storing, accessing, and archiving study products and information and to define top level system requirements for Heavy Lift Launch Vehicle (HLLV) avionics that incorporate Vehicle Health Management (VHM). This report includes technical objectives, methods, assumptions, recommendations, sample data, and issues as specified by DPD No. 772, DR-3. The report is organized into two major subsections, one specific to each of the two tasks defined in the Statement of Work: the Index Database Task and the HLLV Avionics Requirements Task. The Index Database Task resulted in the selection and modification of a commercial database software tool to contain the data developed during the HLLV Avionics Requirements Task. All summary information is addressed within each task's section.

Effect of task load and task load increment on performance and workload

NASA Technical Reports Server (NTRS)

Hancock, P. A.; Williams, G.

1993-01-01

The goal of adaptive automated task allocation is the 'seamless' transfer of work demand between human and machine. Clearly, at the present time, we are far from this objective. One of the barriers to achieving effortless human-machine symbiosis is an inadequate understanding of the way in which operators themselves seek to reallocate demand among their own personal 'resources.' The paper addresses this through an examination of workload response, which scales an individual's reaction to common levels of experienced external demand. The results indicate the primary driver of performance is the absolute level of task demand over the increment in that demand.

Self-reported quality of ADL task performance among patients with COPD exacerbations.

PubMed

Bendixen, Hans Jørgen; Wæhrens, Eva Ejlersen; Wilcke, Jon Torgny; Sørensen, Lisbeth Villemoes

2014-07-01

Patients suffering from chronic obstructive pulmonary disease (COPD) experience problems in the performance of activities of daily living (ADL) tasks. The objective was to examine the self-reported quality of ADL task performance among COPD patients, and to investigate whether age, gender, and routine COPD characteristics correlate with the self-reported ADL ability. Eighty patients admitted to hospital with COPD exacerbations participated. In a cross-sectional study, the patients' self-reported ADL ability was assessed using the ADL-Interview (ADL-I) instrument. Data concerning age, gender, and routine COPD characteristics were drawn from the patients' medical records. The patients reported being inefficient to markedly inefficient when performing ADL tasks within the personal hygiene, toileting, dressing, household, mobility, and transportation domains. While more than 90% of the participants reported increased effort and/or fatigue when performing the ADL tasks, up to 88% of the participants relied on help from others in the performance of general household chores like cooking and shopping. Self-reported ADL ability did not correlate with age, gender, or routine COPD characteristics. Decreased quality of ADL task performance seemed to be extremely common among COPD patients. Therefore, addressing the problems in individually tailored pulmonary rehabilitation programmes may be advantageous.

Posture-Motor and Posture-Ideomotor Dual-Tasking: A Putative Marker of Psychomotor Retardation and Depressive Rumination in Patients With Major Depressive Disorder.

PubMed

Aftanas, Lyubomir I; Bazanova, Olga M; Novozhilova, Nataliya V

2018-01-01

Background: Recent studies have demonstrated that the assessment of postural performance may be a potentially reliable and objective marker of the psychomotor retardation (PMR) in the major depressive disorder (MDD). One of the important facets of MDD-related PMR is reflected in disrupted central mechanisms of psychomotor control, heavily influenced by compelling maladaptive depressive rumination. In view of this we designed a research paradigm that included sequential execution of simple single-posture task followed by more challenging divided attention posture tasks, involving concurring motor and ideomotor workloads. Another difficulty dimension assumed executing of all the tasks with eyes open (EO) (easy) and closed (EC) (difficult) conditions. We aimed at investigating the interplay between the severity of MDD, depressive rumination, and efficiency of postural performance. Methods: Compared with 24 age- and body mass index-matched healthy controls (HCs), 26 patients with MDD sequentially executed three experimental tasks: (1) single-posture task of maintaining a quiet stance (ST), (2) actual posture-motor dual task (AMT); and (3) mental/imaginary posture-motor dual task (MMT). All the tasks were performed in the EO and the EC conditions. The primary dependent variable was the amount of kinetic energy ( E ) expended for the center of pressure deviations (CoPDs), whereas the absolute divided attention cost index showed energy cost to the dual-tasking vs. the single-posture task according to the formula: Δ E = ( E Dual-task - E Single-task ). Results: The signs of PMR in the MDD group were objectively indexed by deficient posture control in the EC condition along with overall slowness of fine motor and ideomotor activity. Another important and probably more challenging feature of the findings was that the posture deficit manifested in the ST condition was substantially and significantly attenuated in the MMT and AMT performance dual-tasking activity. A multiple linear regression analysis evidenced further that the dual-tasking energy cost (i.e., Δ E ) significantly predicted clinical scores of severity of MDD and depressive rumination. Conclusion: The findings allow to suggest that execution of concurrent actual or imaginary fine motor task with closed visual input deallocates attentional resources from compelling maladaptive depressive rumination thereby attenuating severity of absolute dual-tasking energy costs for balance maintenance in patients with MDD. Significance: Quantitative assessment of PMR through measures of the postural performance in dual-tasking may be useful to capture the negative impact of past depressive episodes, optimize the personalized treatment selection, and improve the understanding of the pathophysiological mechanisms underlying MDD.

Components of executive functioning in metamemory.

PubMed

Mäntylä, Timo; Rönnlund, Michael; Kliegel, Matthias

2010-10-01

This study examined metamemory in relation to three basic executive functions (set shifting, working memory updating, and response inhibition) measured as latent variables. Young adults (Experiment 1) and middle-aged adults (Experiment 2) completed a set of executive functioning tasks and the Prospective and Retrospective Memory Questionnaire (PRMQ). In Experiment 1, source recall and face recognition tasks were included as indicators of objective memory performance. In both experiments, analyses of the executive functioning data yielded a two-factor solution, with the updating and inhibition tasks constituting a common factor and the shifting tasks a separate factor. Self-reported memory problems showed low predictive validity, but subjective and objective memory performance were related to different components of executive functioning. In both experiments, set shifting, but not updating and inhibition, was related to PRMQ, whereas source recall showed the opposite pattern of correlations in Experiment 1. These findings suggest that metamemorial judgments reflect selective effects of executive functioning and that individual differences in mental flexibility contribute to self-beliefs of efficacy.

Aging and the visual, haptic, and cross-modal perception of natural object shape.

PubMed

Norman, J Farley; Crabtree, Charles E; Norman, Hideko F; Moncrief, Brandon K; Herrmann, Molly; Kapley, Noah

2006-01-01

One hundred observers participated in two experiments designed to investigate aging and the perception of natural object shape. In the experiments, younger and older observers performed either a same/different shape discrimination task (experiment 1) or a cross-modal matching task (experiment 2). Quantitative effects of age were found in both experiments. The effect of age in experiment 1 was limited to cross-modal shape discrimination: there was no effect of age upon unimodal (ie within a single perceptual modality) shape discrimination. The effect of age in experiment 2 was eliminated when the older observers were either given an unlimited amount of time to perform the task or when the number of response alternatives was decreased. Overall, the results of the experiments reveal that older observers can effectively perceive 3-D shape from both vision and haptics.

Persistent spatial information in the frontal eye field during object-based short-term memory.

PubMed

Clark, Kelsey L; Noudoost, Behrad; Moore, Tirin

2012-08-08

Spatial attention is known to gate entry into visual short-term memory, and some evidence suggests that spatial signals may also play a role in binding features or protecting object representations during memory maintenance. To examine the persistence of spatial signals during object short-term memory, the activity of neurons in the frontal eye field (FEF) of macaque monkeys was recorded during an object-based delayed match-to-sample task. In this task, monkeys were trained to remember an object image over a brief delay, regardless of the locations of the sample or target presentation. FEF neurons exhibited visual, delay, and target period activity, including selectivity for sample location and target location. Delay period activity represented the sample location throughout the delay, despite the irrelevance of spatial information for successful task completion. Furthermore, neurons continued to encode sample position in a variant of the task in which the matching stimulus never appeared in their response field, confirming that FEF maintains sample location independent of subsequent behavioral relevance. FEF neurons also exhibited target-position-dependent anticipatory activity immediately before target onset, suggesting that monkeys predicted target position within blocks. These results show that FEF neurons maintain spatial information during short-term memory, even when that information is irrelevant for task performance.

Magnitude Representation and Working Memory Updating in Children With Arithmetic and Reading Comprehension Disabilities.

PubMed

Pelegrina, Santiago; Capodieci, Agnese; Carretti, Barbara; Cornoldi, Cesare

2015-01-01

It has been argued that children with learning disabilities (LD) encounter severe problems in working memory (WM) tasks, especially when they need to update information stored in their WM. It is not clear, however, to what extent this is due to a generally poor updating ability or to a difficulty specific to the domain to be processed. To examine this issue, two groups of children with arithmetic or reading comprehension LD and a group of typically developing children (9 to 10 years old) were assessed using two updating tasks requiring to select the smallest numbers or objects presented. The results showed that children with an arithmetic disability failed in a number updating task, but not in the object updating task. The opposite was true for the group with poor reading comprehension, whose performance was worse in the object than in the number updating task. It may be concluded that the problem of WM updating in children with LD is also due to a poor representation of the material to be updated. In addition, our findings suggest that the mental representation of the size of objects relates to the semantic representation of the objects' properties and differs from the quantitative representation of numbers. © Hammill Institute on Disabilities 2014.

The Influence of Similarity on Visual Working Memory Representations

PubMed Central

Lin, Po-Han; Luck, Steven J.

2007-01-01

In verbal memory, similarity between items in memory often leads to interference and impaired memory performance. The present study sought to determine whether analogous interference effects would be observed in visual working memory by varying the similarity of the to-be-remembered objects in a color change-detection task. Instead of leading to interference and impaired performance, increased similarity among the items being held in memory led to improved performance. Moreover, when two similar colors were presented along with one dissimilar color, memory performance was better for the similar colors than for the dissimilar color. Similarity produced better performance even when the objects were presented sequentially and even when memory for the first item in the sequence was tested. These findings show that similarity does not lead to interference between representations in visual working memory. Instead, similarity may lead to improved task performance, possibly due to increased stability or precision of the memory representations during maintenance. PMID:19430536

Sensory feedback by peripheral nerve stimulation improves task performance in individuals with upper limb loss using a myoelectric prosthesis.

PubMed

Schiefer, Matthew; Tan, Daniel; Sidek, Steven M; Tyler, Dustin J

2016-02-01

Tactile feedback is critical to grip and object manipulation. Its absence results in reliance on visual and auditory cues. Our objective was to assess the effect of sensory feedback on task performance in individuals with limb loss. Stimulation of the peripheral nerves using implanted cuff electrodes provided two subjects with sensory feedback with intensity proportional to forces on the thumb, index, and middle fingers of their prosthetic hand during object manipulation. Both subjects perceived the sensation on their phantom hand at locations corresponding to the locations of the forces on the prosthetic hand. A bend sensor measured prosthetic hand span. Hand span modulated the intensity of sensory feedback perceived on the thenar eminence for subject 1 and the middle finger for subject 2. We performed three functional tests with the blindfolded subjects. First, the subject tried to determine whether or not a wooden block had been placed in his prosthetic hand. Second, the subject had to locate and remove magnetic blocks from a metal table. Third, the subject performed the Southampton Hand Assessment Procedure (SHAP). We also measured the subject's sense of embodiment with a survey and his self-confidence. Blindfolded performance with sensory feedback was similar to sighted performance in the wooden block and magnetic block tasks. Performance on the SHAP, a measure of hand mechanical function and control, was similar with and without sensory feedback. An embodiment survey showed an improved sense of integration of the prosthesis in self body image with sensory feedback. Sensory feedback by peripheral nerve stimulation improved object discrimination and manipulation, embodiment, and confidence. With both forms of feedback, the blindfolded subjects tended toward results obtained with visual feedback.

Impaired Value Learning for Faces in Preschoolers With Autism Spectrum Disorder.

PubMed

Wang, Quan; DiNicola, Lauren; Heymann, Perrine; Hampson, Michelle; Chawarska, Katarzyna

2018-01-01

One of the common findings in autism spectrum disorder (ASD) is limited selective attention toward social objects, such as faces. Evidence from both human and nonhuman primate studies suggests that selection of objects for processing is guided by the appraisal of object values. We hypothesized that impairments in selective attention in ASD may reflect a disruption of a system supporting learning about object values in the social domain. We examined value learning in social (faces) and nonsocial (fractals) domains in preschoolers with ASD (n = 25) and typically developing (TD) controls (n = 28), using a novel value learning task implemented on a gaze-contingent eye-tracking platform consisting of value learning and a selective attention choice test. Children with ASD performed more poorly than TD controls on the social value learning task, but both groups performed similarly on the nonsocial task. Within-group comparisons indicated that value learning in TD children was enhanced on the social compared to the nonsocial task, but no such enhancement was seen in children with ASD. Performance in the social and nonsocial conditions was correlated in the ASD but not in the TD group. The study provides support for a domain-specific impairment in value learning for faces in ASD, and suggests that, in ASD, value learning in social and nonsocial domains may rely on a shared mechanism. These findings have implications both for models of selective social attention deficits in autism and for identification of novel treatment targets. Copyright © 2017 American Academy of Child and Adolescent Psychiatry. Published by Elsevier Inc. All rights reserved.

The effects of huperzine A and IDRA 21 on visual recognition memory in young macaques

PubMed Central

Malkova, Ludise; Kozikowski, Alan P.; Gale, Karen

2011-01-01

Nootropic agents or cognitive enhancers are purported to improve mental functions such as cognition, memory, or attention. The aim of our study was to determine the effects of two possible cognitive enhancers, huperzine A and IDRA 21, in normal young adult monkeys performing a visual memory task of varying degrees of difficulty. Huperzine A is a reversible acetylcholinesterase (AChE) inhibitor, its administration results in regionally specific increases in acetylcholine levels in the brain. In human clinical trials, Huperzine A resulted in cognitive improvement in patients with mild to moderate form of Alzheimer's disease (AD) showing its potential as a palliative agent in the treatment of AD. IDRA 21 is a positive allosteric modulator of glutamate AMPA receptors. It increases excitatory synaptic strength by attenuating rapid desensitization of AMPA receptors and may thus have beneficial therapeutic effects to ameliorate memory deficits in patients with cognitive impairments, including AD. The present study evaluated the effects of the two drugs in normal, intact, young adult monkeys to determine whether they can result in cognitive enhancement in a system that is presumably functioning optimally. Six young pigtail macaques (Macaca nemestrina) were trained on delayed non-matching-to-sample task, a measure of visual recognition memory, up to criterion of 90% correct responses on each of the four delays (10s, 30s, 60s, and 90s). They were then tested on two versions of the task: Task 1 included the four delays intermixed within a session and the monkeys performed it with the accuracy of 90%. Task 2 included, in each of 24 trials, a list of six objects presented in succession. Two objects from the list were then presented for choice paired with novel objects and following two of the four delays intermixed within a session. This task with a higher mnemonic demand yielded an average performance of 64% correct. Oral administration of huperzine A did not significantly affect the monkeys' performance on either task. However, a significant negative correlation was found between the baseline performance on each delay and the change in performance under huperzine A, suggesting that under conditions in which the subjects were performing poorly (55 – 69%), the drug resulted in improved performance, whereas no improvement was obtained when the baseline was close to 90%. In fact, when the subjects were performing very well, huperzine A tended to reduce the performance accuracy, indicating that in a system that functions optimally, the increased availability of acetylcholine does not improve performance or memory, especially when the animals are close to the maximum performance. In contrast, oral administration of IDRA 21 significantly improved performance on Task 2, especially on the longest delay. This finding supports the potential use of this drug in treatment of cognitive and memory disorders. PMID:21185313

Sex and cultural differences in spatial performance between Japanese and North Americans.

PubMed

Sakamoto, Maiko; Spiers, Mary V

2014-04-01

Previous studies have suggested that Asians perform better than North Americans on spatial tasks but show smaller sex differences. In this study, we evaluated the relationship between long-term experience with a pictorial written language and spatial performance. It was hypothesized that native Japanese Kanji (a complex pictorial written language) educated adults would show smaller sex differences on spatial tasks than Japanese Americans or North Americans without Kanji education. A total of 80 young healthy participants (20 native Japanese speakers, 20 Japanese Americans-non Japanese speaking, and 40 North Americans-non Japanese speaking) completed the Rey Complex Figure Test (RCFT), the Mental Rotations Test (MRT), and customized 2D and 3D spatial object location memory tests. As predicted, main effects revealed men performed better on the MRT and RCFT and women performed better on the spatial object location memory tests. Also, as predicted, native Japanese performed better on all tests than the other groups. In contrast to the other groups, native Japanese showed a decreased magnitude of sex differences on aspects of the RCFT (immediate and delayed recall) and no significant sex difference on the efficiency of the strategy used to copy and encode the RCFT figure. This study lends support to the idea that intensive experience over time with a pictorial written language (i.e., Japanese Kanji) may contribute to increased spatial performance on some spatial tasks as well as diminish sex differences in performance on tasks that most resemble Kanji.

Performance assessment in a flight simulator test—Validation of a space psychology methodology

NASA Astrophysics Data System (ADS)

Johannes, B.; Salnitski, Vyacheslav; Soll, Henning; Rauch, Melina; Goeters, Klaus-Martin; Maschke, Peter; Stelling, Dirk; Eißfeldt, Hinnerk

2007-02-01

The objective assessment of operator performance in hand controlled docking of a spacecraft on a space station has 30 years of tradition and is well established. In the last years the performance assessment was successfully combined with a psycho-physiological approach for the objective assessment of the levels of physiological arousal and psychological load. These methods are based on statistical reference data. For the enhancement of the statistical power of the evaluation methods, both were actually implemented into a comparable terrestrial task: the flight simulator test of DLR in the selection procedure for ab initio pilot applicants for civil airlines. In the first evaluation study 134 male subjects were analysed. Subjects underwent a flight simulator test including three tasks, which were evaluated by instructors applying well-established and standardised rating scales. The principles of the performance algorithms of the docking training were adapted for the automated flight performance assessment. They are presented here. The increased human errors under instrument flight conditions without visual feedback required a manoeuvre recognition algorithm before calculating the deviation of the flown track from the given task elements. Each manoeuvre had to be evaluated independently of former failures. The expert rated performance showed a highly significant correlation with the automatically calculated performance for each of the three tasks: r=.883, r=.874, r=.872, respectively. An automated algorithm successfully assessed the flight performance. This new method will possibly provide a wide range of other future applications in aviation and space psychology.

Selective representation of task-relevant objects and locations in the monkey prefrontal cortex.

PubMed

Everling, Stefan; Tinsley, Chris J; Gaffan, David; Duncan, John

2006-04-01

In the monkey prefrontal cortex (PFC), task context exerts a strong influence on neural activity. We examined different aspects of task context in a temporal search task. On each trial, the monkey (Macaca mulatta) watched a stream of pictures presented to left or right of fixation. The task was to hold fixation until seeing a particular target, and then to make an immediate saccade to it. Sometimes (unilateral task), the attended pictures appeared alone, with a cue at trial onset indicating whether they would be presented to left or right. Sometimes (bilateral task), the attended picture stream (cued side) was accompanied by an irrelevant stream on the opposite side. In two macaques, we recorded responses from a total of 161 cells in the lateral PFC. Many cells (75/161) showed visual responses. Object-selective responses were strongly shaped by task relevance - with stronger responses to targets than to nontargets, failure to discriminate one nontarget from another, and filtering out of information from an irrelevant stimulus stream. Location selectivity occurred rather independently of object selectivity, and independently in visual responses and delay periods between one stimulus and the next. On error trials, PFC activity followed the correct rules of the task, rather than the incorrect overt behaviour. Together, these results suggest a highly programmable system, with responses strongly determined by the rules and requirements of the task performed.

A common neural substrate for perceiving and knowing about color

PubMed Central

Simmons, W. Kyle; Ramjee, Vimal; Beauchamp, Michael S.; McRae, Ken; Martin, Alex; Barsalou, Lawrence W.

2013-01-01

Functional neuroimaging research has demonstrated that retrieving information about object-associated colors activates the left fusiform gyrus in posterior temporal cortex. Although regions near the fusiform have previously been implicated in color perception, it remains unclear whether color knowledge retrieval actually activates the color perception system. Evidence to this effect would be particularly strong if color perception cortex was activated by color knowledge retrieval triggered strictly with linguistic stimuli. To address this question, subjects performed two tasks while undergoing fMRI. First, subjects performed a property verification task using only words to assess conceptual knowledge. On each trial, subjects verified whether a named color or motor property was true of a named object (e.g., TAXI-yellow, HAIR-combed). Next, subjects performed a color perception task. A region of the left fusiform gyrus that was highly responsive during color perception also showed greater activity for retrieving color than motor property knowledge. These data provide the first evidence for a direct overlap in the neural bases of color perception and stored information about object-associated color, and they significantly add to accumulating evidence that conceptual knowledge is grounded in the brain’s modality-specific systems. PMID:17575989

A common neural substrate for perceiving and knowing about color.

PubMed

Simmons, W Kyle; Ramjee, Vimal; Beauchamp, Michael S; McRae, Ken; Martin, Alex; Barsalou, Lawrence W

2007-09-20

Functional neuroimaging research has demonstrated that retrieving information about object-associated colors activates the left fusiform gyrus in posterior temporal cortex. Although regions near the fusiform have previously been implicated in color perception, it remains unclear whether color knowledge retrieval actually activates the color perception system. Evidence to this effect would be particularly strong if color perception cortex was activated by color knowledge retrieval triggered strictly with linguistic stimuli. To address this question, subjects performed two tasks while undergoing fMRI. First, subjects performed a property verification task using only words to assess conceptual knowledge. On each trial, subjects verified whether a named color or motor property was true of a named object (e.g., TAXI-yellow, HAIR-combed). Next, subjects performed a color perception task. A region of the left fusiform gyrus that was highly responsive during color perception also showed greater activity for retrieving color than motor property knowledge. These data provide the first evidence for a direct overlap in the neural bases of color perception and stored information about object-associated color, and they significantly add to accumulating evidence that conceptual knowledge is grounded in the brain's modality-specific systems.

Numerosity underestimation with item similarity in dynamic visual display.

PubMed

Au, Ricky K C; Watanabe, Katsumi

2013-01-01

The estimation of numerosity of a large number of objects in a static visual display is possible even at short durations. Such coarse approximations of numerosity are distinct from subitizing, in which the number of objects can be reported with high precision when a small number of objects are presented simultaneously. The present study examined numerosity estimation of visual objects in dynamic displays and the effect of object similarity on numerosity estimation. In the basic paradigm (Experiment 1), two streams of dots were presented and observers were asked to indicate which of the two streams contained more dots. Streams consisting of dots that were identical in color were judged as containing fewer dots than streams where the dots were different colors. This underestimation effect for identical visual items disappeared when the presentation rate was slower (Experiment 1) or the visual display was static (Experiment 2). In Experiments 3 and 4, in addition to the numerosity judgment task, observers performed an attention-demanding task at fixation. Task difficulty influenced observers' precision in the numerosity judgment task, but the underestimation effect remained evident irrespective of task difficulty. These results suggest that identical or similar visual objects presented in succession might induce substitution among themselves, leading to an illusion that there are few items overall and that exploiting attentional resources does not eliminate the underestimation effect.

Compact Heat Exchanger Design and Testing for Advanced Reactors and Advanced Power Cycles

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

Sun, Xiaodong; Zhang, Xiaoqin; Christensen, Richard

The goal of the proposed research is to demonstrate the thermal hydraulic performance of innovative surface geometries in compact heat exchangers used as intermediate heat exchangers (IHXs) and recuperators for the supercritical carbon dioxide (s-CO 2) Brayton cycle. Printed-circuit heat exchangers (PCHEs) are the primary compact heat exchangers of interest. The overall objectives are: To develop optimized PCHE designs for different working fluid combinations including helium to s-CO 2, liquid salt to s-CO 2, sodium to s-CO 2, and liquid salt to helium; To experimentally and numerically investigate thermal performance, thermal stress and failure mechanism of PCHEs under various transients;more » and To study diffusion bonding techniques for elevated-temperature alloys and examine post-test material integrity of the PCHEs. The project objectives were accomplished by defining and executing five different tasks corresponding to these specific objectives. The first task involved a thorough literature review and a selection of IHX candidates with different surface geometries as well as a summary of prototypic operational conditions. The second task involved optimization of PCHE design with numerical analyses of thermal-hydraulic performances and mechanical integrity. The subsequent task dealt with the development of testing facilities and engineering design of PCHE to be tested in s-CO 2 fluid conditions. The next task involved experimental investigation and validation of the thermal-hydraulic performances and thermal stress distribution of prototype PCHEs manufactured with particular surface geometries. The last task involved an investigation of diffusion bonding process and posttest destructive testing to validate mechanical design methods adopted in the design process. The experimental work utilized the two test facilities at The Ohio State University (OSU) including one existing High-Temperature Helium Test Facility (HTHF) and the newly developed s-CO 2 test loop (STL) facility and s-CO 2 test facility at University of Wisconsin – Madison (UW).« less

The role of judgment frames and task precision in object attention: Reduced template sharpness limits dual-object performance.

PubMed

Liu, Shiau-Hua; Dosher, Barbara Anne; Lu, Zhong-Lin

2009-06-01

Multiple attributes of a single-object are often processed more easily than attributes of different objects-a phenomenon associated with object attention. Here we investigate the influence of two factors, judgment frames and judgment precision, on dual-object report deficits as an index of object attention. [Han, S., Dosher, B., & Lu, Z.-L. (2003). Object attention revisited: Identifying mechanisms and boundary conditions. Psychological Science, 14, 598-604] predicted that consistency of the frame for judgments about two separate objects could reduce or eliminate the expression of object attention limitations. The current studies examine the effects of judgment frames and of task precision in orientation identification and find that dual-object report deficits within one feature are indeed affected modestly by the congruency of the judgments and more substantially by the required precision of judgments. The observed dual-object deficits affected contrast thresholds for incongruent frame conditions and for high precision judgments and reduce psychometric asymptotes. These dual-object deficits reflect a combined effect of multiplicative noise and external noise exclusion in dual-object conditions, both related to the effects of attention on the tuning of perceptual templates. These results have implications for modification of object attention theory, for understanding limitations on concurrent tasks.

Effort in Multitasking: Local and Global Assessment of Effort.

PubMed

Kiesel, Andrea; Dignath, David

2017-01-01

When performing multiple tasks in succession, self-organization of task order might be superior compared to external-controlled task schedules, because self-organization allows optimizing processing modes and thus reduces switch costs, and it increases commitment to task goals. However, self-organization is an additional executive control process that is not required if task order is externally specified and as such it is considered as time-consuming and effortful. To compare self-organized and externally controlled task scheduling, we suggest assessing global subjective and objectives measures of effort in addition to local performance measures. In our new experimental approach, we combined characteristics of dual tasking settings and task switching settings and compared local and global measures of effort in a condition with free choice of task sequence and a condition with cued task sequence. In a multi-tasking environment, participants chose the task order while the task requirement of the not-yet-performed task remained the same. This task preview allowed participants to work on the previously non-chosen items in parallel and resulted in faster responses and fewer errors in task switch trials than in task repetition trials. The free-choice group profited more from this task preview than the cued group when considering local performance measures. Nevertheless, the free-choice group invested more effort than the cued group when considering global measures. Thus, self-organization in task scheduling seems to be effortful even in conditions in which it is beneficiary for task processing. In a second experiment, we reduced the possibility of task preview for the not-yet-performed tasks in order to hinder efficient self-organization. Here neither local nor global measures revealed substantial differences between the free-choice and a cued task sequence condition. Based on the results of both experiments, we suggest that global assessment of effort in addition to local performance measures might be a useful tool for multitasking research.

Task frequency as a function of age for the powerline technician trade.

PubMed

Parkhouse, Wade; Gall, Brent

2004-05-15

It is traditionally believed that worker productivity declines with age. The greatest contributor to this stereotype, particularly in physically demanding jobs, is that older workers can no longer maintain their sustained level of work due to the age-associated decline in physical capacity. The objective of this study was to determine the change in the frequency of task performance as a function of age in the power line technician (PLT) trade. The task requirements of the PLT occupation were determined through the use of a detailed job demands analysis (JDA) and the frequency at which these tasks were performed was acquired through a survey derived from the JDA. The results of the survey were assessed as a function of age. Older lineworkers (> or = 50 years) were found to spend more time working on the ground whereas the younger PLTs (< or = 39 years) more frequently performed the climbing tasks and the corresponding work on the poles and towers. In contrast the older PLTs performed all pushing/pulling tasks at a greater or equal frequency to that of the younger lineworkers. Despite these differences the frequency of task performance is similar across the age groups studied.

A virtual work space for both hands manipulation with coherency between kinesthetic and visual sensation

NASA Technical Reports Server (NTRS)

Ishii, Masahiro; Sukanya, P.; Sato, Makoto

1994-01-01

This paper describes the construction of a virtual work space for tasks performed by two handed manipulation. We intend to provide a virtual environment that encourages users to accomplish tasks as they usually act in a real environment. Our approach uses a three dimensional spatial interface device that allows the user to handle virtual objects by hand and be able to feel some physical properties such as contact, weight, etc. We investigated suitable conditions for constructing our virtual work space by simulating some basic assembly work, a face and fit task. We then selected the conditions under which the subjects felt most comfortable in performing this task and set up our virtual work space. Finally, we verified the possibility of performing more complex tasks in this virtual work space by providing simple virtual models and then let the subjects create new models by assembling these components. The subjects can naturally perform assembly operations and accomplish the task. Our evaluation shows that this virtual work space has the potential to be used for performing tasks that require two-handed manipulation or cooperation between both hands in a natural manner.

Histidine-decarboxylase knockout mice show deficient nonreinforced episodic object memory, improved negatively reinforced water-maze performance, and increased neo- and ventro-striatal dopamine turnover.

PubMed

Dere, Ekrem; De Souza-Silva, Maria A; Topic, Bianca; Spieler, Richard E; Haas, Helmut L; Huston, Joseph P

2003-01-01

The brain's histaminergic system has been implicated in hippocampal synaptic plasticity, learning, and memory, as well as brain reward and reinforcement. Our past pharmacological and lesion studies indicated that the brain's histamine system exerts inhibitory effects on the brain's reinforcement respective reward system reciprocal to mesolimbic dopamine systems, thereby modulating learning and memory performance. Given the close functional relationship between brain reinforcement and memory processes, the total disruption of brain histamine synthesis via genetic disruption of its synthesizing enzyme, histidine decarboxylase (HDC), in the mouse might have differential effects on learning dependent on the task-inherent reinforcement contingencies. Here, we investigated the effects of an HDC gene disruption in the mouse in a nonreinforced object exploration task and a negatively reinforced water-maze task as well as on neo- and ventro-striatal dopamine systems known to be involved in brain reward and reinforcement. Histidine decarboxylase knockout (HDC-KO) mice had higher dihydrophenylacetic acid concentrations and a higher dihydrophenylacetic acid/dopamine ratio in the neostriatum. In the ventral striatum, dihydrophenylacetic acid/dopamine and 3-methoxytyramine/dopamine ratios were higher in HDC-KO mice. Furthermore, the HDC-KO mice showed improved water-maze performance during both hidden and cued platform tasks, but deficient object discrimination based on temporal relationships. Our data imply that disruption of brain histamine synthesis can have both memory promoting and suppressive effects via distinct and independent mechanisms and further indicate that these opposed effects are related to the task-inherent reinforcement contingencies.

Haptic-Based Perception-Empathy Biofeedback Enhances Postural Motor Learning During High-Cognitive Load Task in Healthy Older Adults

PubMed Central

Yasuda, Kazuhiro; Saichi, Kenta; Iwata, Hiroyasu

2018-01-01

Falls and fall-induced injuries are major global public health problems, and sensory input impairment in older adults results in significant limitations in feedback-type postural control. A haptic-based biofeedback (BF) system can be used for augmenting somatosensory input in older adults, and the application of this BF system can increase the objectivity of the feedback and encourage comparison with that provided by a trainer. Nevertheless, an optimal BF system that focuses on interpersonal feedback for balance training in older adults has not been proposed. Thus, we proposed a haptic-based perception-empathy BF system that provides information regarding the older adult's center-of-foot pressure pattern to the trainee and trainer for refining the motor learning effect. The first objective of this study was to examine the effect of this balance training regimen in healthy older adults performing a postural learning task. Second, this study aimed to determine whether BF training required high cognitive load to clarify its practicability in real-life settings. Twenty older adults were assigned to two groups: BF and control groups. Participants in both groups tried balance training in the single-leg stance while performing a cognitive task (i.e., serial subtraction task). Retention was tested 24 h later. Testing comprised balance performance measures (i.e., 95% confidence ellipse area and mean velocity of sway) and dual-task performance (number of responses and correct answers). Measurements of postural control using a force plate revealed that the stability of the single-leg stance was significantly lower in the BF group than in the control group during the balance task. The BF group retained the improvement in the 95% confidence ellipse area 24 h after the retention test. Results of dual-task performance during the balance task were not different between the two groups. These results confirmed the potential benefit of the proposed balance training regimen in designing successful motor learning programs for preventing falls in older adults. PMID:29868597

Haptic-Based Perception-Empathy Biofeedback Enhances Postural Motor Learning During High-Cognitive Load Task in Healthy Older Adults.

PubMed

Yasuda, Kazuhiro; Saichi, Kenta; Iwata, Hiroyasu

2018-01-01

Falls and fall-induced injuries are major global public health problems, and sensory input impairment in older adults results in significant limitations in feedback-type postural control. A haptic-based biofeedback (BF) system can be used for augmenting somatosensory input in older adults, and the application of this BF system can increase the objectivity of the feedback and encourage comparison with that provided by a trainer. Nevertheless, an optimal BF system that focuses on interpersonal feedback for balance training in older adults has not been proposed. Thus, we proposed a haptic-based perception-empathy BF system that provides information regarding the older adult's center-of-foot pressure pattern to the trainee and trainer for refining the motor learning effect. The first objective of this study was to examine the effect of this balance training regimen in healthy older adults performing a postural learning task. Second, this study aimed to determine whether BF training required high cognitive load to clarify its practicability in real-life settings. Twenty older adults were assigned to two groups: BF and control groups. Participants in both groups tried balance training in the single-leg stance while performing a cognitive task (i.e., serial subtraction task). Retention was tested 24 h later. Testing comprised balance performance measures (i.e., 95% confidence ellipse area and mean velocity of sway) and dual-task performance (number of responses and correct answers). Measurements of postural control using a force plate revealed that the stability of the single-leg stance was significantly lower in the BF group than in the control group during the balance task. The BF group retained the improvement in the 95% confidence ellipse area 24 h after the retention test. Results of dual-task performance during the balance task were not different between the two groups. These results confirmed the potential benefit of the proposed balance training regimen in designing successful motor learning programs for preventing falls in older adults.

Infants' development of object permanence: a refined methodology and new evidence of Piaget's hypothesized ordinality.

PubMed

Kramer, J A; Hill, K T; Cohen, L B

1975-03-01

To investigate Piaget's theory of object concept development, a series of 6 tasks was administered in a combined longitudinal/cross-sectional design incorporating a number of methodological controls. The tasks spanned the entire sensorimotor period and included single versus sequential displacements combined with visible or invisible hidings. 36 infants from 5 to 32 months of age at initial testing were drawn equally from day-care and home settings. All infants received the 6 tasks during each of 3 testing sessions over a 6-month period. Clear evidence was obtained for task ordinality as proposed by Piaget, with ordinality coefficients ranging from .71 to .82 for the 3 testing sessions. Performance changes across the 3 sessions were also ordinal in 80% of the cases. Expected age, task, and session effects and accompanying interactions were also obtained.

Post-Training Reversible Inactivation of the Hippocampus Enhances Novel Object Recognition Memory

ERIC Educational Resources Information Center

Oliveira, Ana M. M.; Hawk, Joshua D.; Abel, Ted; Havekes, Robbert

2010-01-01

Research on the role of the hippocampus in object recognition memory has produced conflicting results. Previous studies have used permanent hippocampal lesions to assess the requirement for the hippocampus in the object recognition task. However, permanent hippocampal lesions may impact performance through effects on processes besides memory…

Self-Motion Impairs Multiple-Object Tracking

ERIC Educational Resources Information Center

Thomas, Laura E.; Seiffert, Adriane E.

2010-01-01

Investigations of multiple-object tracking aim to further our understanding of how people perform common activities such as driving in traffic. However, tracking tasks in the laboratory have overlooked a crucial component of much real-world object tracking: self-motion. We investigated the hypothesis that keeping track of one's own movement…

Mission planning for autonomous systems

NASA Technical Reports Server (NTRS)

Pearson, G.

1987-01-01

Planning is a necessary task for intelligent, adaptive systems operating independently of human controllers. A mission planning system that performs task planning by decomposing a high-level mission objective into subtasks and synthesizing a plan for those tasks at varying levels of abstraction is discussed. Researchers use a blackboard architecture to partition the search space and direct the focus of attention of the planner. Using advanced planning techniques, they can control plan synthesis for the complex planning tasks involved in mission planning.

Development of Piagetian object permanence in a grey parrot (Psittacus erithacus).

PubMed

Pepperberg, I M; Willner, M R; Gravitz, L B

1997-03-01

The authors evaluated the ontogenetic performance of a grey parrot (Psittacus erithacus) on object permanence tasks designed for human infants. Testing began when the bird was 8 weeks old, prior to fledging and weaning. Because adult grey parrots understand complex invisible displacements (I. M. Pepperberg & F. A. Kozak, 1986), the authors continued weekly testing until the current subject completed all of I. C. Uzgiris and J. Hunt's (1975) Scale 1 tasks. Stage 6 object permanence with respect to these tasks emerged at 22 weeks, after the bird had fledged but before it was completely weaned. Although the parrot progressed more rapidly overall than other species that have been tested ontogenetically, the subject similarly exhibited a behavioral plateau part way through the study. Additional tests, administered at 8 and 12 months as well as to an adult grey parrot, demonstrated, respectively, that these birds have some representation of a hidden object and understand advanced invisible displacements.

Intact haptic priming in normal aging and Alzheimer's disease: evidence for dissociable memory systems.

PubMed

Ballesteros, Soledad; Reales, José Manuel

2004-01-01

This study is the first to report complete priming in Alzheimer's disease (AD) patients and older control subjects for objects presented haptically. To investigate possible dissociations between implicit and explicit objects representations, young adults, Alzheimer's patients, and older controls performed a speeded object naming task followed by a recognition task. Similar haptic priming was exhibited by the three groups, although young adults responded faster than the two older groups. Furthermore, there was no difference in performance between the two healthy groups. On the other hand, younger and older healthy adults did not differ on explicit recognition while, as expected, AD patients were highly impaired. The double dissociation suggests that different memory systems mediate both types of memory tasks. The preservation of intact haptic priming in AD provides strong support to the idea that object implicit memory is mediated by a memory system that is different from the medial-temporal diencephalic system underlying explicit memory, which is impaired early in AD. Recent imaging and behavioral studies suggest that the implicit memory system may depend on extrastriate areas of the occipital cortex although somatosensory cortical mechanisms may also be involved.

Joint Terminal Attack Controllers Sensors and Lasers Modernization

DTIC Science & Technology

2012-09-01

and Evaluation Activity MCSC Marine Corps Systems Command MCT Marine Corps Task MCTL Marine Corps Task List MEMS MicroElectroMechanical Systems...functional relationship of the key performance requirements was associated to Marine Corps Tasks ( MCT ), Critical Operational Issues (COIs...to an accomplishment of mission objectives and achievement of desired results [5]. All COIs are linked to a MCT , which are provided within the

What Do Eye Gaze Metrics Tell Us about Motor Imagery?

PubMed

Poiroux, Elodie; Cavaro-Ménard, Christine; Leruez, Stéphanie; Lemée, Jean Michel; Richard, Isabelle; Dinomais, Mickael

2015-01-01

Many of the brain structures involved in performing real movements also have increased activity during imagined movements or during motor observation, and this could be the neural substrate underlying the effects of motor imagery in motor learning or motor rehabilitation. In the absence of any objective physiological method of measurement, it is currently impossible to be sure that the patient is indeed performing the task as instructed. Eye gaze recording during a motor imagery task could be a possible way to "spy" on the activity an individual is really engaged in. The aim of the present study was to compare the pattern of eye movement metrics during motor observation, visual and kinesthetic motor imagery (VI, KI), target fixation, and mental calculation. Twenty-two healthy subjects (16 females and 6 males), were required to perform tests in five conditions using imagery in the Box and Block Test tasks following the procedure described by Liepert et al. Eye movements were analysed by a non-invasive oculometric measure (SMI RED250 system). Two parameters describing gaze pattern were calculated: the index of ocular mobility (saccade duration over saccade + fixation duration) and the number of midline crossings (i.e. the number of times the subjects gaze crossed the midline of the screen when performing the different tasks). Both parameters were significantly different between visual imagery and kinesthesic imagery, visual imagery and mental calculation, and visual imagery and target fixation. For the first time we were able to show that eye movement patterns are different during VI and KI tasks. Our results suggest gaze metric parameters could be used as an objective unobtrusive approach to assess engagement in a motor imagery task. Further studies should define how oculomotor parameters could be used as an indicator of the rehabilitation task a patient is engaged in.

Work assignments, delegation of tasks and job satisfaction among Danish dental hygienists.

PubMed

Hach, M; Aaberg, K B; Lempert, S M; Danielsen, B

2017-08-01

Recent legislation in Denmark has made it possible for dentists to delegate their tasks to dental hygienists. Previous studies have shown that Danish dental hygienists primarily were performing assignments within their own work field. These assignments include prophylaxis or instructing patients in oral health care. However, studies have also shown that Danish dental hygienists performed dental nurse assignments such as chair-side assistance, unit cleaning and disinfection of instruments. The objectives of this study were to investigate (i) the range of work assignments performed by Danish dental hygienists, (ii) the types of dentist tasks performed by Danish dental hygienists and (iii) job satisfaction among Danish dental hygienists. Dental hygienists graduating in 2004-2007 were invited to participate in this study. Participants answered an email-distributed questionnaire. The questionnaire consisted of questions regarding job satisfaction, assignments performed, postgraduate course attendance, receiving assistance from a dental nurse and which work assignments Danish dental hygienists wish to perform in the future. The results of this study showed that 90% of Danish dental hygienists were satisfied with their job and 52% were performing dentists' tasks. Among dentists' tasks performed by Danish dental hygienists, invasive caries therapy was the most frequently performed task. The type of assignments performed by Danish dental hygienists today appears to be changing compared to previous studies. From initially performing prophylaxis and chair-side assistance for the dentist, Danish dental hygienists today are performing a wider range of tasks which includes dentists' tasks. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Dissociating electrophysiological correlates of subjective, objective, and correct memory in investigating the emotion-induced recognition bias.

PubMed

Windmann, Sabine; Hill, Holger

2014-10-01

Performance on tasks requiring discrimination of at least two stimuli can be viewed either from an objective perspective (referring to actual stimulus differences), or from a subjective perspective (corresponding to participant's responses). Using event-related potentials recorded during an old/new recognition memory test involving emotionally laden and neutral words studied either blockwise or randomly intermixed, we show here how the objective perspective (old versus new items) yields late effects of blockwise emotional item presentation at parietal sites that the subjective perspective fails to find, whereas the subjective perspective ("old" versus "new" responses) is more sensitive to early effects of emotion at anterior sites than the objective perspective. Our results demonstrate the potential advantage of dissociating the subjective and the objective perspective onto task performance (in addition to analyzing trials with correct responses), especially for investigations of illusions and information processing biases, in behavioral and cognitive neuroscience studies. Copyright © 2014 Elsevier Inc. All rights reserved.

In a demanding task, three-handed manipulation is preferred to two-handed manipulation

NASA Astrophysics Data System (ADS)

Abdi, Elahe; Burdet, Etienne; Bouri, Mohamed; Himidan, Sharifa; Bleuler, Hannes

2016-02-01

Equipped with a third hand under their direct control, surgeons may be able to perform certain surgical interventions alone; this would reduce the need for a human assistant and related coordination difficulties. However, does human performance improve with three hands compared to two hands? To evaluate this possibility, we carried out a behavioural study on the performance of naive adults catching objects with three virtual hands controlled by their two hands and right foot. The subjects could successfully control the virtual hands in a few trials. With this control strategy, the workspace of the hands was inversely correlated with the task velocity. The comparison of performance between the three and two hands control revealed no significant difference of success in catching falling objects and in average effort during the tasks. Subjects preferred the three handed control strategy, found it easier, with less physical and mental burden. Although the coordination of the foot with the natural hands increased trial after trial, about two minutes of practice was not sufficient to develop a sense of ownership towards the third arm.

In a demanding task, three-handed manipulation is preferred to two-handed manipulation.

PubMed

Abdi, Elahe; Burdet, Etienne; Bouri, Mohamed; Himidan, Sharifa; Bleuler, Hannes

2016-02-25

Equipped with a third hand under their direct control, surgeons may be able to perform certain surgical interventions alone; this would reduce the need for a human assistant and related coordination difficulties. However, does human performance improve with three hands compared to two hands? To evaluate this possibility, we carried out a behavioural study on the performance of naive adults catching objects with three virtual hands controlled by their two hands and right foot. The subjects could successfully control the virtual hands in a few trials. With this control strategy, the workspace of the hands was inversely correlated with the task velocity. The comparison of performance between the three and two hands control revealed no significant difference of success in catching falling objects and in average effort during the tasks. Subjects preferred the three handed control strategy, found it easier, with less physical and mental burden. Although the coordination of the foot with the natural hands increased trial after trial, about two minutes of practice was not sufficient to develop a sense of ownership towards the third arm.

CLUSTERS OF TASKS PERFORMED BY WASHINGTON STATE FARM OPERATORS ENGAGED IN SEVEN TYPES OF AGRICULTURAL PRODUCTION--GRAIN, DAIRY, FORESTRY, LIVESTOCK, POULTRY, HORTICULTURE, AND GENERAL FARMING. REPORT NO. 27.

ERIC Educational Resources Information Center

LONG, GILBERT A.

THE OBJECTIVE OF THIS STUDY WAS TO OBTAIN UP-TO-DATE FACTS ABOUT CLUSTERS OF TASKS PERFORMED BY WASHINGTON STATE FARM OPERATORS ENGAGED PRIMARILY IN PRODUCING GRAIN, LIVESTOCK, DAIRY COMMODITIES, POULTRY, FOREST PRODUCTS, HORTICULTURAL COMMODITIES, AND GENERAL FARMING COMMODITIES. FROM A RANDOM SAMPLE OF 267 FARMERS REPRESENTING THOSE CATEGORIES…

Guidelines for Conducting a Training Effectiveness Evaluation (TEE). Volume 1. TEE Evaluator’s Handbook

DTIC Science & Technology

1985-02-01

by drawing prerequisite lines, the relationships between all subordinate skills and knowledges and the terminal objective. Thus, for purposes of...functions, tasks, or skills below it, rate the relationship of the performances shown in the superordinate box to those in the subordinate boxes...A useful format for displaying performance relationships between team functions and subordinate tasks or communication and coordination skills

Arthroscopic skills assessment and use of box model for training in arthroscopic surgery using Sawbones – “FAST” workstation

PubMed Central

Goyal, Saumitra; Radi, Mohamed Abdel; Ramadan, Islam Karam-allah; Said, Hatem Galal

2016-01-01

Purpose: Arthroscopic skills training outside the operative room may decrease risks and errors by trainee surgeons. There is a need of simple objective method for evaluating proficiency and skill of arthroscopy trainees using simple bench model of arthroscopic simulator. The aim of this study is to correlate motor task performance to level of prior arthroscopic experience and establish benchmarks for training modules. Methods: Twenty orthopaedic surgeons performed a set of tasks to assess a) arthroscopic triangulation, b) navigation, c) object handling and d) meniscus trimming using SAWBONES “FAST” arthroscopy skills workstation. Time to completion and the errors were computed. The subjects were divided into four levels; “Novice”, “Beginner”, “Intermediate” and “Advanced” based on previous arthroscopy experience, for analyses of performance. Results: The task performance under transparent dome was not related to experience of the surgeon unlike opaque dome, highlighting the importance of hand-eye co-ordination required in arthroscopy. Median time to completion for each task improved as the level of experience increased and this was found to be statistically significant (p < .05) e.g. time for maze navigation (Novice – 166 s, Beginner – 135.5 s, Intermediate – 100 s, Advance – 97.5 s) and the similar results for all tasks. Majority (>85%) of subjects across all the levels reported improvement in performance with sequential tasks. Conclusion: Use of the arthroscope requires visuo-spatial coordination which is a skill that develops with practice. This simple box model can reliably differentiate the arthroscopic skills based on experience and can be used to monitor progression of skills of trainees in institutions. PMID:27801643

The effects of fatigue on performance in simulated nursing work.

PubMed

Barker, Linsey M; Nussbaum, Maury A

2011-09-01

Fatigue is associated with increased rates of medical errors and healthcare worker injuries, yet existing research in this sector has not considered multiple dimensions of fatigue simultaneously. This study evaluated hypothesised causal relationships between mental and physical fatigue and performance. High and low levels of mental and physical fatigue were induced in 16 participants during simulated nursing work tasks in a laboratory setting. Task-induced changes in fatigue dimensions were quantified using both subjective and objective measures, as were changes in performance on physical and mental tasks. Completing the simulated work tasks increased total fatigue, mental fatigue and physical fatigue in all experimental conditions. Higher physical fatigue adversely affected measures of physical and mental performance, whereas higher mental fatigue had a positive effect on one measure of mental performance. Overall, these results suggest causal effects between manipulated levels of mental and physical fatigue and task-induced changes in mental and physical performance. STATEMENT OF RELEVANCE: Nurse fatigue and performance has implications for patient and provider safety. Results from this study demonstrate the importance of a multidimensional view of fatigue in understanding the causal relationships between fatigue and performance. The findings can guide future work aimed at predicting fatigue-related performance decrements and designing interventions.

Analysis of the Structure of Surgical Activity for a Suturing and Knot-Tying Task

PubMed Central

Vedula, S. Swaroop; Malpani, Anand O.; Tao, Lingling; Chen, George; Gao, Yixin; Poddar, Piyush; Ahmidi, Narges; Paxton, Christopher; Vidal, Rene; Khudanpur, Sanjeev; Hager, Gregory D.; Chen, Chi Chiung Grace

2016-01-01

Background Surgical tasks are performed in a sequence of steps, and technical skill evaluation includes assessing task flow efficiency. Our objective was to describe differences in task flow for expert and novice surgeons for a basic surgical task. Methods We used a hierarchical semantic vocabulary to decompose and annotate maneuvers and gestures for 135 instances of a surgeon’s knot performed by 18 surgeons. We compared counts of maneuvers and gestures, and analyzed task flow by skill level. Results Experts used fewer gestures to perform the task (26.29; 95% CI = 25.21 to 27.38 for experts vs. 31.30; 95% CI = 29.05 to 33.55 for novices) and made fewer errors in gestures than novices (1.00; 95% CI = 0.61 to 1.39 vs. 2.84; 95% CI = 2.3 to 3.37). Transitions among maneuvers, and among gestures within each maneuver for expert trials were more predictable than novice trials. Conclusions Activity segments and state flow transitions within a basic surgical task differ by surgical skill level, and can be used to provide targeted feedback to surgical trainees. PMID:26950551

Cognition, personality, and stress in budgerigars, Melopsittacus undulatus.

PubMed

Medina-García, Angela; Jawor, Jodie M; Wright, Timothy F

2017-01-01

To study the fitness effects of individual variation in cognitive traits, it is paramount to understand whether traits such as personality and physiological stress influence cognitive performance. We first tested whether budgerigars showed both consistent personalities and cognitive performance across time and tasks. We tested object and food neophobia, and exploratory behavior. We measured cognitive performance in habituation, ability to solve foraging problems, spatial memory, and seed discrimination tasks. Budgerigars showed consistency in their neophobic tendencies and these tendencies were associated with their exploratory behavior. Birds were also consistent in how they performed in most of the cognitive tasks (temporal consistency), but were not consistent in their performance across tasks (context consistency). Neither corticosterone levels (baseline and stress-induced) showed a significant relationship with either cognitive or personality measures. Neophobic and exploratory tendencies determined the willingness of birds to engage only in the seed discrimination task. Such tendencies also had a significant effect on problem-solving ability. Our results suggest that consistent individual differences in cognitive performance along with consistent differences in personality could determine response to environmental change and therefore have important fitness consequences.

The power of Kawaii: viewing cute images promotes a careful behavior and narrows attentional focus.

PubMed

Nittono, Hiroshi; Fukushima, Michiko; Yano, Akihiro; Moriya, Hiroki

2012-01-01

Kawaii (a Japanese word meaning "cute") things are popular because they produce positive feelings. However, their effect on behavior remains unclear. In this study, three experiments were conducted to examine the effects of viewing cute images on subsequent task performance. In the first experiment, university students performed a fine motor dexterity task before and after viewing images of baby or adult animals. Performance indexed by the number of successful trials increased after viewing cute images (puppies and kittens; M ± SE=43.9 ± 10.3% improvement) more than after viewing images that were less cute (dogs and cats; 11.9 ± 5.5% improvement). In the second experiment, this finding was replicated by using a non-motor visual search task. Performance improved more after viewing cute images (15.7 ± 2.2% improvement) than after viewing less cute images (1.4 ± 2.1% improvement). Viewing images of pleasant foods was ineffective in improving performance (1.2 ± 2.1%). In the third experiment, participants performed a global-local letter task after viewing images of baby animals, adult animals, and neutral objects. In general, global features were processed faster than local features. However, this global precedence effect was reduced after viewing cute images. Results show that participants performed tasks requiring focused attention more carefully after viewing cute images. This is interpreted as the result of a narrowed attentional focus induced by the cuteness-triggered positive emotion that is associated with approach motivation and the tendency toward systematic processing. For future applications, cute objects may be used as an emotion elicitor to induce careful behavioral tendencies in specific situations, such as driving and office work.

The Power of Kawaii: Viewing Cute Images Promotes a Careful Behavior and Narrows Attentional Focus

PubMed Central

Nittono, Hiroshi; Fukushima, Michiko; Yano, Akihiro; Moriya, Hiroki

2012-01-01

Kawaii (a Japanese word meaning “cute”) things are popular because they produce positive feelings. However, their effect on behavior remains unclear. In this study, three experiments were conducted to examine the effects of viewing cute images on subsequent task performance. In the first experiment, university students performed a fine motor dexterity task before and after viewing images of baby or adult animals. Performance indexed by the number of successful trials increased after viewing cute images (puppies and kittens; M ± SE = 43.9±10.3% improvement) more than after viewing images that were less cute (dogs and cats; 11.9±5.5% improvement). In the second experiment, this finding was replicated by using a non-motor visual search task. Performance improved more after viewing cute images (15.7±2.2% improvement) than after viewing less cute images (1.4±2.1% improvement). Viewing images of pleasant foods was ineffective in improving performance (1.2±2.1%). In the third experiment, participants performed a global–local letter task after viewing images of baby animals, adult animals, and neutral objects. In general, global features were processed faster than local features. However, this global precedence effect was reduced after viewing cute images. Results show that participants performed tasks requiring focused attention more carefully after viewing cute images. This is interpreted as the result of a narrowed attentional focus induced by the cuteness-triggered positive emotion that is associated with approach motivation and the tendency toward systematic processing. For future applications, cute objects may be used as an emotion elicitor to induce careful behavioral tendencies in specific situations, such as driving and office work. PMID:23050022

Mastery motivation as a predictor of occupational performance following upper limb intervention for school-aged children with congenital hemiplegia.

PubMed

Miller, Laura; Ziviani, Jenny; Ware, Robert S; Boyd, Roslyn N

2014-10-01

To determine the extent to which children's mastery motivation predicts occupational performance outcomes following upper limb intervention (ULI). In this cohort study, participants received 45 hours of ULI, either in an intensive group-based or distributed individualized model. The Dimensions of Mastery Questionnaire (DMQ) measured mastery motivation at baseline. Occupational performance outcomes were assessed at baseline and 13 weeks' post-intervention using the Canadian Occupational Performance Measure (COPM). Multivariable models determined the contribution of mastery motivation to COPM outcome irrespective of group membership. Forty-two children with congenital hemiplegia (29 males, 13 females; mean age 7y 8mo [SD 2y 2mo]; range 5y 1mo-12y 8mo; Manual Ability Classification System [MACS] I=20 and II=22; predominant motor type unilateral spastic n=41) participated in the study. Significant gains were seen in COPM performance and satisfaction scores (p<0.001) post-intervention with no between group differences. Children who had greater persistence with object-oriented tasks (p=0.02) and better manual ability (p=0.03) achieved higher COPM performance scores at 13 weeks. Children's persistence on object-oriented tasks was the strongest predictor of COPM satisfaction (p=0.01). Children's persistence with object-oriented tasks as well as manual abilities needs to be considered when undertaking ULI. Predetermining children's motivational predispositions can assist clinicians to tailor therapy sessions individually based on children's strengths, contributing to effective engagement in ULI. © 2014 Mac Keith Press.

Do detour tasks provide accurate assays of inhibitory control?

PubMed Central

Whiteside, Mark A.; Laker, Philippa R.; Beardsworth, Christine E.

2018-01-01

Transparent Cylinder and Barrier tasks are used to purportedly assess inhibitory control in a variety of animals. However, we suspect that performances on these detour tasks are influenced by non-cognitive traits, which may result in inaccurate assays of inhibitory control. We therefore reared pheasants under standardized conditions and presented each bird with two sets of similar tasks commonly used to measure inhibitory control. We recorded the number of times subjects incorrectly attempted to access a reward through transparent barriers, and their latencies to solve each task. Such measures are commonly used to infer the differential expression of inhibitory control. We found little evidence that their performances were consistent across the two different Putative Inhibitory Control Tasks (PICTs). Improvements in performance across trials showed that pheasants learned the affordances of each specific task. Critically, prior experience of transparent tasks, either Barrier or Cylinder, also improved subsequent inhibitory control performance on a novel task, suggesting that they also learned the general properties of transparent obstacles. Individual measures of persistence, assayed in a third task, were positively related to their frequency of incorrect attempts to solve the transparent inhibitory control tasks. Neophobia, Sex and Body Condition had no influence on individual performance. Contrary to previous studies of primates, pheasants with poor performance on PICTs had a wider dietary breadth assayed using a free-choice task. Our results demonstrate that in systems or taxa where prior experience and differences in development cannot be accounted for, individual differences in performance on commonly used detour-dependent PICTS may reveal more about an individual's prior experience of transparent objects, or their motivation to acquire food, than providing a reliable measure of their inhibitory control. PMID:29593115

Characterizing Impulsivity in Mania

PubMed Central

Strakowski, Stephen M.; Fleck, David E.; DelBello, Melissa P.; Adler, Caleb M.; Shear, Paula K.; McElroy, Susan L.; Keck, Paul E.; Moss, Quinton; Cerullo, Michael A.; Kotwal, Renu; Arndt, Stephan

2008-01-01

Objective To determine whether specific aspects of impulsivity (response disinhibition, inability to delay gratification, inattention) differ between healthy and bipolar manic subjects, and whether these aspects of impulsivity were associated with each other and severity of affective symptoms. Methods Performance of 70 bipolar I manic or mixed patients was compared to that of 34 healthy subjects on three tasks specifically designed to study response inhibition, ability to delay gratification, and attention; namely a stop signal task, a delayed reward task, and a continuous performance task respectively. Correlations among tasks and with symptom ratings were also performed. Results Bipolar subjects demonstrated significant deficits on all three tasks as compared to healthy subjects. Performance on the three tasks was largely independent. Task performance was not significantly associated with the severity of affective symptom ratings. However, measures of response inhibition and attention were sensitive to medication effects. Differences in the delayed reward task were independent of medication effects or symptom ratings. During the delayed reward task, although bipolar patients made their choices more slowly than healthy subjects, they were significantly more likely to choose a smaller, but more quickly obtained reward. Moreover performance on this task was not associated with performance on the other impulsivity measures. Manic patients showed more impulsive responding than mixed patients. Conclusions Bipolar I manic patients demonstrate deficits on tests of various aspects of impulsivity as compared to healthy subjects. Some of these differences between groups may be mediated by medication effects. Findings suggested that inability to delay gratification (i.e., delayed reward task) was not simply a result of the speed of decision making or inattention, but rather that it reflected differences between bipolar and healthy subjects in the valuation of reward relative to delay. PMID:19133965

Impact of sleep deprivation and obstructive sleep apnea syndrome on daytime vigilance and driving performance: a laboratory perspective.

PubMed

Pizza, F; Contardi, S; Mondini, S; Cirignotta, F

2012-01-01

To study the impact of sleepiness, a well-established cause of car accidents, on driving ability, we designed a 30-min monotonous simulated driving task. Our simulated driving task encompasses both primary vehicle control (standard deviation of lane position, crash occurrence) and secondary tasks (type and reaction times to divided attention tasks). Driving simulator data were correlated to subjective (state/trait) and objective (MSLT/MWT) sleepiness measures in healthy subjects undergoing sleep deprivation (SD) and in obstructive sleep apnea (OSAS) patients. SD induced severe sleepiness during nighttime, when state sleepiness increased while primary vehicle control ability worsened. After SD, driving ability decreased and was inversely correlated to subjective and objective sleepiness at MSLT. OSAS patients driving ability was well correlated to objective sleepiness, with inverse correlation to sleep propensity at the MSLT and even more strict relation with the ability to maintain wakefulness at the MWT. Sleepiness worsens driving ability in healthy subjects after SD and in OSAS patients. Driving ability correlates with subjective and objective sleepiness measures, in particular to the ability to maintain wakefulness.

Direct manipulation of virtual objects

NASA Astrophysics Data System (ADS)

Nguyen, Long K.

Interacting with a Virtual Environment (VE) generally requires the user to correctly perceive the relative position and orientation of virtual objects. For applications requiring interaction in personal space, the user may also need to accurately judge the position of the virtual object relative to that of a real object, for example, a virtual button and the user's real hand. This is difficult since VEs generally only provide a subset of the cues experienced in the real world. Complicating matters further, VEs presented by currently available visual displays may be inaccurate or distorted due to technological limitations. Fundamental physiological and psychological aspects of vision as they pertain to the task of object manipulation were thoroughly reviewed. Other sensory modalities -- proprioception, haptics, and audition -- and their cross-interactions with each other and with vision are briefly discussed. Visual display technologies, the primary component of any VE, were canvassed and compared. Current applications and research were gathered and categorized by different VE types and object interaction techniques. While object interaction research abounds in the literature, pockets of research gaps remain. Direct, dexterous, manual interaction with virtual objects in Mixed Reality (MR), where the real, seen hand accurately and effectively interacts with virtual objects, has not yet been fully quantified. An experimental test bed was designed to provide the highest accuracy attainable for salient visual cues in personal space. Optical alignment and user calibration were carefully performed. The test bed accommodated the full continuum of VE types and sensory modalities for comprehensive comparison studies. Experimental designs included two sets, each measuring depth perception and object interaction. The first set addressed the extreme end points of the Reality-Virtuality (R-V) continuum -- Immersive Virtual Environment (IVE) and Reality Environment (RE). This validated, linked, and extended several previous research findings, using one common test bed and participant pool. The results provided a proven method and solid reference points for further research. The second set of experiments leveraged the first to explore the full R-V spectrum and included additional, relevant sensory modalities. It consisted of two full-factorial experiments providing for rich data and key insights into the effect of each type of environment and each modality on accuracy and timeliness of virtual object interaction. The empirical results clearly showed that mean depth perception error in personal space was less than four millimeters whether the stimuli presented were real, virtual, or mixed. Likewise, mean error for the simple task of pushing a button was less than four millimeters whether the button was real or virtual. Mean task completion time was less than one second. Key to the high accuracy and quick task performance time observed was the correct presentation of the visual cues, including occlusion, stereoscopy, accommodation, and convergence. With performance results already near optimal level with accurate visual cues presented, adding proprioception, audio, and haptic cues did not significantly improve performance. Recommendations for future research include enhancement of the visual display and further experiments with more complex tasks and additional control variables.

Identification of Tasks in Photo-Offset Lithography Occupations.

ERIC Educational Resources Information Center

Iowa State Dept. of Public Instruction, Des Moines. Div. of Career Education.

The research project was designed to provide data pertaining to performance tasks in specific occupations in various areas of vocational/technical education. The data presented in the document is intended to be used to develop appropriate objectives and curricular content to assist in the preparation of individuals entering the specific…

Equipment-Device Task Commonality Analysis and Transfer of Training.

ERIC Educational Resources Information Center

Caro, Paul W.

Procedures were developed to enable training personnel systematically and objectively to determine the potential utility of training devices for teaching how to perform missions in operational rotary wing aircraft. These procedures allow comparison of task stimulus and response elements with corresponding elements in synthetic training equipment.…

Between-object and within-object saccade programming in a visual search task.

PubMed

Vergilino-Perez, Dorine; Findlay, John M

2006-07-01

The role of the perceptual organization of the visual display on eye movement control was examined in two experiments using a task where a two-saccade sequence was directed toward either a single elongated object or three separate shorter objects. In the first experiment, we examined the consequences for the second saccade of a small displacement of the whole display during the first saccade. We found that between-object saccades compensated for the displacement to aim for a target position on the new object whereas within-object saccades did not show compensation but were coded as a fixed motor vector applied irrespective of wherever the preceding saccade landed. In the second experiment, we extended the paradigm to examine saccades performed in different directions. The results suggest that the within-object and between-object saccade distinction is an essential feature of saccadic planning.

Optimization of Skill Retention in the U.S. Army through Initial Training Analysis and Design. Volume 1.

DTIC Science & Technology

1983-05-01

observed end-of-course scores for tasks .- trained to criterion. e MGA software was calibrated to provide retention estimates at two levels of...exceed the MGA estimates. Thirty-five out of forty, or 87.5,o0 of the tasks met this expectation. . * For these first trial data, MGA software predicts...Objective: The objective of this effort was to perform an operational test of the capability of MGA Skill Training and Retention (STAR©) software to

Gender differences in memory for objects and their locations: a study on automatic versus controlled encoding and retrieval contexts.

PubMed

De Goede, Maartje; Postma, Albert

2008-04-01

Object-location memory is the only spatial task where female subjects have been shown to outperform males. This result is not consistent across all studies, and may be due to the combination of the multi-component structure of object location memory with the conditions under which different studies were done. Possible gender differences in object location memory and its component object identity memory were assessed in the present study. In order to disentangle these two components, an object location memory task (in which objects had to be relocated in daily environments), and a separate object identity recognition task were carried out. This study also focused on the conditions under which object locations were encoded and retrieved. Only half of the participants were aware of the fact that object locations had to be retrieved later on. Moreover, by applying the 'process dissociation procedure' to the object location memory assessments and the 'remember-know' paradigm to the object identity measure, the amount of explicit (conscious) and implicit (unconscious) retrieval was estimated for each component. In general, females performed better than males on the object location memory task. However, when controlled for object identity memory, females no longer outperformed males, whereas they did not obtain a higher general object identity memory score, nor did they have more explicit or implicit recollection of the object identities. These complicated effects might stem from a difference between males and females, in the way locations or associations between objects and locations are retrieved. In general, participants had more explicit (conscious) recollection than implicit (unconscious) recollection. No effect of encoding context was found, nor any interaction effect of gender, encoding and retrieval context.

Efficiency in Rule- vs. Plan-Based Movements Is Modulated by Action-Mode

PubMed Central

Scheib, Jean P. P.; Stoll, Sarah; Thürmer, J. Lukas; Randerath, Jennifer

2018-01-01

The rule/plan motor cognition (RPMC) paradigm elicits visually indistinguishable motor outputs, resulting from either plan- or rule-based action-selection, using a combination of essentially interchangeable stimuli. Previous implementations of the RPMC paradigm have used pantomimed movements to compare plan- vs. rule-based action-selection. In the present work we attempt to determine the generalizability of previous RPMC findings to real object interaction by use of a grasp-to-rotate task. In the plan task, participants had to use prospective planning to achieve a comfortable post-handle rotation hand posture. The rule task used implementation intentions (if-then rules) leading to the same comfortable end-state. In Experiment A, we compare RPMC performance of 16 healthy participants in pantomime and real object conditions of the experiment, within-subjects. Higher processing efficiency of rule- vs. plan-based action-selection was supported by diffusion model analysis. Results show a significant response-time increase in the pantomime condition compared to the real object condition and a greater response-time advantage of rule-based vs. plan-based actions in the pantomime compared to the real object condition. In Experiment B, 24 healthy participants performed the real object RPMC task in a task switching vs. a blocked condition. Results indicate that plan-based action-selection leads to longer response-times and less efficient information processing than rule-based action-selection in line with previous RPMC findings derived from the pantomime action-mode. Particularly in the task switching mode, responses were faster in the rule compared to the plan task suggesting a modulating influence of cognitive load. Overall, results suggest an advantage of rule-based action-selection over plan-based action-selection; whereby differential mechanisms appear to be involved depending on the action-mode. We propose that cognitive load is a factor that modulates the advantageous effect of implementation intentions in motor cognition on different levels as illustrated by the varying speed advantages and the variation in diffusion parameters per action-mode or condition, respectively. PMID:29593612

The Role of Motivation, Glucose and Self-Control in the Antisaccade Task

PubMed Central

Kelly, Claire L.; Sünram-Lea, Sandra I.; Crawford, Trevor J.

2015-01-01

Research shows that self-control is resource limited and there is a gradual weakening in consecutive self-control task performance akin to muscle fatigue. A body of evidence suggests that the resource is glucose and consuming glucose reduces this effect. This study examined the effect of glucose on performance in the antisaccade task - which requires self-control through generating a voluntary eye movement away from a target - following self-control exertion in the Stroop task. The effects of motivation and individual differences in self-control were also explored. In a double-blind design, 67 young healthy adults received a 25g glucose or inert placebo drink. Glucose did not enhance antisaccade performance following self-control exertion in the Stroop task. Motivation however, predicted performance on the antisaccade task; more specifically high motivation ameliorated performance decrements observed after initial self-control exertion. In addition, individuals with high levels of self-control performed better on certain aspects of the antisaccade task after administration of a glucose drink. The results of this study suggest that the antisaccade task might be a powerful paradigm, which could be used as a more objective measure of self-control. Moreover, the results indicate that level of motivation and individual differences in self-control should be taken into account when investigating deficiencies in self-control following prior exertion. PMID:25826334

Assessing performance characteristics of sediment basins constructed in Franklin County.

DOT National Transportation Integrated Search

2012-08-01

The objective of the research project was to monitor the performance of newly designed : sediment basins that were constructed on the ALDOT 502 project in Franklin County. The : project included four tasks: (1) assess performance characteristics of s...

Mechanical Objects and the Engineering Learner: An Experimental Study of How the Presence of Objects Affects Students' Performance on Engineering Related Tasks

ERIC Educational Resources Information Center

Bairaktarova, Diana N.

2013-01-01

People display varying levels of interaction with the mechanical objects in their environment; engineers in particular as makers and users of these objects display a higher level of interaction with them. Investigating the educational potential of mechanical objects in stimulating and supporting learning in engineering is warranted by the fact…

Comparison of Physiological and Psychological Relaxation Using Measurements of Heart Rate Variability, Prefrontal Cortex Activity, and Subjective Indexes after Completing Tasks with and without Foliage Plants

PubMed Central

Park, Sin-Ae

2017-01-01

The objective of this study was to compare physiological and psychological relaxation by assessing heart rate variability (HRV), prefrontal cortex activity, and subjective indexes while subjects performed a task with and without foliage plants. In a crossover experimental design, 24 university students performed a task transferring pots with and without a foliage plant for 3 min. HRV and oxyhemoglobin (oxy-Hb) concentration in the prefrontal cortex were continuously measured. Immediately thereafter, subjective evaluation of emotions was performed using a modified semantic differential (SD) method and a profile of mood state questionnaire (POMS). Results showed that the natural logarithmic (ln) ratio of low frequency/high frequency, as an estimate of sympathetic nerve activity, was significantly lower while performing the task with foliage plants for the average 3 min measurement interval. Oxy-Hb concentration in the left prefrontal cortex showed a tendency to decrease in the 2–3 min interval in the task with foliage plants compared to the task without plants. Moreover, significant psychological relaxation according to POMS score and SD was demonstrated when the task involved foliage plants. In conclusion, the task involving foliage plants led to more physiological and psychological relaxation compared with the task without foliage plants. PMID:28930169

Comparison of Physiological and Psychological Relaxation Using Measurements of Heart Rate Variability, Prefrontal Cortex Activity, and Subjective Indexes after Completing Tasks with and without Foliage Plants.

PubMed

Park, Sin-Ae; Song, Chorong; Oh, Yun-Ah; Miyazaki, Yoshifumi; Son, Ki-Cheol

2017-09-20

The objective of this study was to compare physiological and psychological relaxation by assessing heart rate variability (HRV), prefrontal cortex activity, and subjective indexes while subjects performed a task with and without foliage plants. In a crossover experimental design, 24 university students performed a task transferring pots with and without a foliage plant for 3 min. HRV and oxyhemoglobin (oxy-Hb) concentration in the prefrontal cortex were continuously measured. Immediately thereafter, subjective evaluation of emotions was performed using a modified semantic differential (SD) method and a profile of mood state questionnaire (POMS). Results showed that the natural logarithmic (ln) ratio of low frequency/high frequency, as an estimate of sympathetic nerve activity, was significantly lower while performing the task with foliage plants for the average 3 min measurement interval. Oxy-Hb concentration in the left prefrontal cortex showed a tendency to decrease in the 2-3 min interval in the task with foliage plants compared to the task without plants. Moreover, significant psychological relaxation according to POMS score and SD was demonstrated when the task involved foliage plants. In conclusion, the task involving foliage plants led to more physiological and psychological relaxation compared with the task without foliage plants.

Working memory and inattentional blindness.

PubMed

Bredemeier, Keith; Simons, Daniel J

2012-04-01

Individual differences in working memory predict many aspects of cognitive performance, especially for tasks that demand focused attention. One negative consequence of focused attention is inattentional blindness, the failure to notice unexpected objects when attention is engaged elsewhere. Yet, the relationship between individual differences in working memory and inattentional blindness is unclear; some studies have found that higher working memory capacity is associated with greater noticing, but others have found no direct association. Given the theoretical and practical significance of such individual differences, more definitive tests are needed. In two studies with large samples, we tested the relationship between multiple working memory measures and inattentional blindness. Individual differences in working memory predicted the ability to perform an attention-demanding tracking task, but did not predict the likelihood of noticing an unexpected object present during the task. We discuss the reasons why we might not expect such individual differences in noticing and why other studies may have found them.

Creativity and Memory: Effects of an Episodic Specificity Induction on Divergent Thinking

PubMed Central

Madore, Kevin P.; Addis, Donna Rose; Schacter, Daniel L.

2015-01-01

After receiving an episodic specificity induction - brief training in recollecting details of a recent event - people produce more episodic details when imagining future events and solving means-end problems than after receiving a control induction not focused on episodic retrieval. Here we show for the first time that an episodic specificity induction also enhances divergent creative thinking. In Experiment 1, participants exhibited a selective boost on a divergent thinking task that involves generating unusual uses of common objects after a specificity induction compared with a control induction; by contrast, performance was similar on an object association task thought to involve little divergent thinking. In Experiment 2, we replicated the specificity induction effect on divergent thinking using a different control induction, and also found that participants performed similarly on a convergent thinking task following both inductions. These experiments provide novel evidence that episodic memory is involved in divergent creative thinking. PMID:26205963

Selective Maintenance in Visual Working Memory Does Not Require Sustained Visual Attention

PubMed Central

Hollingworth, Andrew; Maxcey-Richard, Ashleigh M.

2012-01-01

In four experiments, we tested whether sustained visual attention is required for the selective maintenance of objects in VWM. Participants performed a color change-detection task. During the retention interval, a valid cue indicated the item that would be tested. Change detection performance was higher in the valid-cue condition than in a neutral-cue control condition. To probe the role of visual attention in the cuing effect, on half of the trials, a difficult search task was inserted after the cue, precluding sustained attention on the cued item. The addition of the search task produced no observable decrement in the magnitude of the cuing effect. In a complementary test, search efficiency was not impaired by simultaneously prioritizing an object for retention in VWM. The results demonstrate that selective maintenance in VWM can be dissociated from the locus of visual attention. PMID:23067118

Selective maintenance in visual working memory does not require sustained visual attention.

PubMed

Hollingworth, Andrew; Maxcey-Richard, Ashleigh M

2013-08-01

In four experiments, we tested whether sustained visual attention is required for the selective maintenance of objects in visual working memory (VWM). Participants performed a color change-detection task. During the retention interval, a valid cue indicated the item that would be tested. Change-detection performance was higher in the valid-cue condition than in a neutral-cue control condition. To probe the role of visual attention in the cuing effect, on half of the trials, a difficult search task was inserted after the cue, precluding sustained attention on the cued item. The addition of the search task produced no observable decrement in the magnitude of the cuing effect. In a complementary test, search efficiency was not impaired by simultaneously prioritizing an object for retention in VWM. The results demonstrate that selective maintenance in VWM can be dissociated from the locus of visual attention. 2013 APA, all rights reserved

The effect of monocular target blur on simulated telerobotic manipulation

NASA Technical Reports Server (NTRS)

Liu, Andrew; Stark, Lawrence

1991-01-01

A simulation involving three types of telerobotic tasks that require information about the spatial position of objects is reported. This is similar to the results of psychophysical experiments examining the effect of blur on stereoacuity. It is suggested that other psychophysical experimental results could be used to predict operator performance for other telerobotic tasks. It is demonstrated that refractive errors in the helmet-mounted stereo display system can affect performance in the three types of telerobotic tasks. The results of two sets of experiments indicate that monocular target blur of two diopters or more degrades stereo display performance to the level of monocular displays. This indicates that moderate levels of visual degradation that affect the operator's stereoacuity may eliminate the performance advantage of stereo displays.

Preliminary investigation of motion requirements for the simulation of helicopter hover tasks

NASA Technical Reports Server (NTRS)

Parrish, R. V.

1980-01-01

Data from a preliminary experiment are presented which attempted to define a helicopter hover task that would allow the detection of objectively-measured differences in fixed base/moving base simulator performance. The addition of heave, pitch, and roll movement of a ship at sea to the hover task, by means of an adaption of a simulator g-seat, potentially fulfills the desired definition. The feasibility of g-seat substitution for platform motion can be investigated utilizing this task.

Inattentional blindness for a gun during a simulated police vehicle stop.

PubMed

Simons, Daniel J; Schlosser, Michael D

2017-01-01

People often fail to notice unexpected objects and events when they are focusing attention on something else. Most studies of this "inattentional blindness" use unexpected objects that are irrelevant to the primary task and to the participant (e.g., gorillas in basketball games or colored shapes in computerized tracking tasks). Although a few studies have examined noticing rates for personally relevant or task-relevant unexpected objects, few have done so in a real-world context with objects that represent a direct threat to the participant. In this study, police academy trainees (n = 100) and experienced police officers (n = 75) engaged in a simulated vehicle traffic stop in which they approached a vehicle to issue a warning or citation for running a stop sign. The driver was either passive and cooperative or agitated and hostile when complying with the officer's instructions. Overall, 58% of the trainees and 33% of the officers failed to notice a gun positioned in full view on the passenger dashboard. The driver's style of interaction had little effect on noticing rates for either group. People can experience inattentional blindness for a potentially dangerous object in a naturalistic real-world context, even when noticing that object would change how they perform their primary task and even when their training focuses on awareness of potential threats.

Anterior Temporal Lobe Morphometry Predicts Categorization Ability.

PubMed

Garcin, Béatrice; Urbanski, Marika; Thiebaut de Schotten, Michel; Levy, Richard; Volle, Emmanuelle

2018-01-01

Categorization is the mental operation by which the brain classifies objects and events. It is classically assessed using semantic and non-semantic matching or sorting tasks. These tasks show a high variability in performance across healthy controls and the cerebral bases supporting this variability remain unknown. In this study we performed a voxel-based morphometry study to explore the relationships between semantic and shape categorization tasks and brain morphometric differences in 50 controls. We found significant correlation between categorization performance and the volume of the gray matter in the right anterior middle and inferior temporal gyri. Semantic categorization tasks were associated with more rostral temporal regions than shape categorization tasks. A significant relationship was also shown between white matter volume in the right temporal lobe and performance in the semantic tasks. Tractography revealed that this white matter region involved several projection and association fibers, including the arcuate fasciculus, inferior fronto-occipital fasciculus, uncinate fasciculus, and inferior longitudinal fasciculus. These results suggest that categorization abilities are supported by the anterior portion of the right temporal lobe and its interaction with other areas.

BDNF Expression in Perirhinal Cortex is Associated with Exercise-Induced Improvement in Object Recognition Memory

PubMed Central

Hopkins, Michael E.; Bucci, David J.

2010-01-01

Physical exercise induces widespread neurobiological adaptations and improves learning and memory. Most research in this field has focused on hippocampus-based spatial tasks and changes in brain-derived neurotrophic factor (BDNF) as a putative substrate underlying exercise-induced cognitive improvements. Chronic exercise can also be anxiolytic and causes adaptive changes in stress reactivity. The present study employed a perirhinal cortex-dependent object recognition task as well as the elevated plus maze to directly test for interactions between the cognitive and anxiolytic effects of exercise in male Long Evans rats. Hippocampal and perirhinal cortex tissue was collected to determine whether the relationship between BDNF and cognitive performance extends to this non-spatial and non-hippocampal-dependent task. We also examined whether the cognitive improvements persisted once the exercise regimen was terminated. Our data indicate that 4 weeks of voluntary exercise every-other-day improved object recognition memory. Importantly, BDNF expression in the perirhinal cortex of exercising rats was strongly correlated with object recognition memory. Exercise also decreased anxiety-like behavior, however there was no evidence to support a relationship between anxiety-like behavior and performance on the novel object recognition task. There was a trend for a negative relationship between anxiety-like behavior and hippocampal BDNF. Neither the cognitive improvements nor the relationship between cognitive function and perirhinal BDNF levels persisted after 2 weeks of inactivity. These are the first data demonstrating that region-specific changes in BDNF protein levels are correlated with exercise-induced improvements in non-spatial memory, mediated by structures outside the hippocampus and are consistent with the theory that, with regard to object recognition, the anxiolytic and cognitive effects of exercise may be mediated through separable mechanisms. PMID:20601027

Preserved cognitive functions with age are determined by domain-dependent shifts in network responsivity

PubMed Central

Samu, Dávid; Campbell, Karen L.; Tsvetanov, Kamen A.; Shafto, Meredith A.; Brayne, Carol; Bullmore, Edward T.; Calder, Andrew C.; Cusack, Rhodri; Dalgleish, Tim; Duncan, John; Henson, Richard N.; Matthews, Fiona E.; Marslen-Wilson, William D.; Rowe, James B.; Cheung, Teresa; Davis, Simon; Geerligs, Linda; Kievit, Rogier; McCarrey, Anna; Mustafa, Abdur; Price, Darren; Taylor, Jason R.; Treder, Matthias; van Belle, Janna; Williams, Nitin; Bates, Lauren; Emery, Tina; Erzinçlioglu, Sharon; Gadie, Andrew; Gerbase, Sofia; Georgieva, Stanimira; Hanley, Claire; Parkin, Beth; Troy, David; Auer, Tibor; Correia, Marta; Gao, Lu; Green, Emma; Henriques, Rafael; Allen, Jodie; Amery, Gillian; Amunts, Liana; Barcroft, Anne; Castle, Amanda; Dias, Cheryl; Dowrick, Jonathan; Fair, Melissa; Fisher, Hayley; Goulding, Anna; Grewal, Adarsh; Hale, Geoff; Hilton, Andrew; Johnson, Frances; Johnston, Patricia; Kavanagh-Williamson, Thea; Kwasniewska, Magdalena; McMinn, Alison; Norman, Kim; Penrose, Jessica; Roby, Fiona; Rowland, Diane; Sargeant, John; Squire, Maggie; Stevens, Beth; Stoddart, Aldabra; Stone, Cheryl; Thompson, Tracy; Yazlik, Ozlem; Barnes, Dan; Dixon, Marie; Hillman, Jaya; Mitchell, Joanne; Villis, Laura; Tyler, Lorraine K.

2017-01-01

Healthy ageing has disparate effects on different cognitive domains. The neural basis of these differences, however, is largely unknown. We investigated this question by using Independent Components Analysis to obtain functional brain components from 98 healthy participants aged 23–87 years from the population-based Cam-CAN cohort. Participants performed two cognitive tasks that show age-related decrease (fluid intelligence and object naming) and a syntactic comprehension task that shows age-related preservation. We report that activation of task-positive neural components predicts inter-individual differences in performance in each task across the adult lifespan. Furthermore, only the two tasks that show performance declines with age show age-related decreases in task-positive activation of neural components and decreasing default mode (DM) suppression. Our results suggest that distributed, multi-component brain responsivity supports cognition across the adult lifespan, and the maintenance of this, along with maintained DM deactivation, characterizes successful ageing and may explain differential ageing trajectories across cognitive domains. PMID:28480894

Learning the ideal observer for SKE detection tasks by use of convolutional neural networks (Cum Laude Poster Award)

NASA Astrophysics Data System (ADS)

Zhou, Weimin; Anastasio, Mark A.

2018-03-01

It has been advocated that task-based measures of image quality (IQ) should be employed to evaluate and optimize imaging systems. Task-based measures of IQ quantify the performance of an observer on a medically relevant task. The Bayesian Ideal Observer (IO), which employs complete statistical information of the object and noise, achieves the upper limit of the performance for a binary signal classification task. However, computing the IO performance is generally analytically intractable and can be computationally burdensome when Markov-chain Monte Carlo (MCMC) techniques are employed. In this paper, supervised learning with convolutional neural networks (CNNs) is employed to approximate the IO test statistics for a signal-known-exactly and background-known-exactly (SKE/BKE) binary detection task. The receiver operating characteristic (ROC) curve and the area under the ROC curve (AUC) are compared to those produced by the analytically computed IO. The advantages of the proposed supervised learning approach for approximating the IO are demonstrated.

Preserved cognitive functions with age are determined by domain-dependent shifts in network responsivity.

PubMed

Samu, Dávid; Campbell, Karen L; Tsvetanov, Kamen A; Shafto, Meredith A; Tyler, Lorraine K

2017-05-08

Healthy ageing has disparate effects on different cognitive domains. The neural basis of these differences, however, is largely unknown. We investigated this question by using Independent Components Analysis to obtain functional brain components from 98 healthy participants aged 23-87 years from the population-based Cam-CAN cohort. Participants performed two cognitive tasks that show age-related decrease (fluid intelligence and object naming) and a syntactic comprehension task that shows age-related preservation. We report that activation of task-positive neural components predicts inter-individual differences in performance in each task across the adult lifespan. Furthermore, only the two tasks that show performance declines with age show age-related decreases in task-positive activation of neural components and decreasing default mode (DM) suppression. Our results suggest that distributed, multi-component brain responsivity supports cognition across the adult lifespan, and the maintenance of this, along with maintained DM deactivation, characterizes successful ageing and may explain differential ageing trajectories across cognitive domains.

How Are Bodies Special? Effects Of Body Features On Spatial Reasoning

PubMed Central

Yu, Alfred B.; Zacks, Jeffrey M.

2015-01-01

Embodied views of cognition argue that cognitive processes are influenced by bodily experience. This implies that when people make spatial judgments about human bodies, they bring to bear embodied knowledge that affects spatial reasoning performance. Here, we examined the specific contribution to spatial reasoning of visual features associated with the human body. We used two different tasks to elicit distinct visuospatial transformations: object-based transformations, as elicited in typical mental rotation tasks, and perspective transformations, used in tasks in which people deliberately adopt the egocentric perspective of another person. Body features facilitated performance in both tasks. This result suggests that observers are particularly sensitive to the presence of a human head and body, and that these features allow observers to quickly recognize and encode the spatial configuration of a figure. Contrary to prior reports, this facilitation was not related to the transformation component of task performance. These results suggest that body features facilitate task components other than spatial transformation, including the encoding of stimulus orientation. PMID:26252072

Cognitive costs of encoding novel natural activities: Can "learning by doing" be distracting and deceptive?

PubMed

von Stülpnagel, Rul; Schult, Janette C; Richter, Claudia; Steffens, Melanie C

2016-01-01

Findings from action memory research suggest that the enactment of simple actions and naturalistic activities results in similar memory performance to that from their observation. However, little is known about potential differences between the conditions during the encoding of the to-be-studied actions and activities. We analysed the cognitive costs of encoding two novel naturalistic activities studied via enactment or via observation in four experiments. In addition to memory performance, we measured objective cognitive costs with a secondary task and subjective cognitive costs with repeated ratings of mental effort and estimates of general activity difficulty. Memory performance was comparable across study conditions throughout all experiments. The enactment of activities repeatedly resulted in slower reaction times in the secondary task than did observation, suggesting higher objective costs. In contrast, subjective costs were rated lower after enactment than after observation. Findings from a pantomimic enactment condition suggested that the low ratings of subjective costs after enactment represent a misinterpretation of task demands. Our findings imply that the widespread belief about "learning by doing" as an easy way of learning does not stem from an actual advantage in memory performance, but rather from continuous feedback about one's performance resulting from enactment.

Space Station Application of Simulator-Developed Aircrew Coordination and Performance Measures

NASA Technical Reports Server (NTRS)

Murphy, Miles

1985-01-01

This paper summarizes a study in progress at NASA/Ames Research Center to develop measures of aircrew coordination and decision-making factors and to relate them to flight task performance, that is, to crew and system performance measures. The existence of some similar interpersonal process and task performance requirements suggests a potential application of these methods in space station crew research -- particularly research conducted in ground-based mock-ups. The secondary objective of this study should also be of interest: to develop information on crew process and performance for application in developing crew training programs.

Interactive Tools for Measuring Visual Scanning Performance and Reaction Time.

PubMed

Brooks, Johnell; Seeanner, Julia; Hennessy, Sarah; Manganelli, Joseph; Crisler, Matthew; Rosopa, Patrick; Jenkins, Casey; Anderson, Michael; Drouin, Nathalie; Belle, Leah; Truesdail, Constance; Tanner, Stephanie

Occupational therapists are constantly searching for engaging, high-technology interactive tasks that provide immediate feedback to evaluate and train clients with visual scanning deficits. This study examined the relationship between two tools: the VISION COACH™ interactive light board and the Functional Object Detection © (FOD) Advanced driving simulator scenario. Fifty-four healthy drivers, ages 21-66 yr, were divided into three age groups. Participants performed braking response and visual target (E) detection tasks of the FOD Advanced driving scenario, followed by two sets of three trials using the VISION COACH Full Field 60 task. Results showed no significant effect of age on FOD Advanced performance but a significant effect of age on VISION COACH performance. Correlations showed that participants' performance on both braking and E detection tasks were significantly positively correlated with performance on the VISION COACH (.37 < r < .40, p < .01). These tools provide new options for therapists. Copyright © 2017 by the American Occupational Therapy Association, Inc.

Theoretical Value Belief, Cognitive Ability, and Personality as Predictors of Student Performance in Object-Oriented Programming Environments

ERIC Educational Resources Information Center

Hall, Dianne J.; Cegielski, Casey G.; Wade, James N.

2006-01-01

The research described in this article reports the results of a study designed to evaluate the relationship among object-oriented (OO) computer programming task performance and a student's (1) theoretical value belief, (2) cognitive ability, and (3) personality. The results of this study do not support the assertion that cognitive ability is a…

Influences on Group Productivity 1: Factors Inherent in the Task. A bibliographic Synopsis

DTIC Science & Technology

1983-04-15

organization structure and job attitudes and job behavior . Variables: Structure defined as the positions and parts of k-ganizations and their systematic and...relatively enduring relationship to each other. Attitudes defined in the broadest sense of "opinion concerning some object." Job behavior is...theory specifying the relations among task structure, leadership behavior and group performance. Indeoendent variables: Degree of structure of task (ac

The fate of task-irrelevant visual motion: perceptual load versus feature-based attention.

PubMed

Taya, Shuichiro; Adams, Wendy J; Graf, Erich W; Lavie, Nilli

2009-11-18

We tested contrasting predictions derived from perceptual load theory and from recent feature-based selection accounts. Observers viewed moving, colored stimuli and performed low or high load tasks associated with one stimulus feature, either color or motion. The resultant motion aftereffect (MAE) was used to evaluate attentional allocation. We found that task-irrelevant visual features received less attention than co-localized task-relevant features of the same objects. Moreover, when color and motion features were co-localized yet perceived to belong to two distinct surfaces, feature-based selection was further increased at the expense of object-based co-selection. Load theory predicts that the MAE for task-irrelevant motion would be reduced with a higher load color task. However, this was not seen for co-localized features; perceptual load only modulated the MAE for task-irrelevant motion when this was spatially separated from the attended color location. Our results suggest that perceptual load effects are mediated by spatial selection and do not generalize to the feature domain. Feature-based selection operates to suppress processing of task-irrelevant, co-localized features, irrespective of perceptual load.

Visual space under free viewing conditions.

PubMed

Doumen, Michelle J A; Kappers, Astrid M L; Koenderink, Jan J

2005-10-01

Most research on visual space has been done under restricted viewing conditions and in reduced environments. In our experiments, observers performed an exocentric pointing task, a collinearity task, and a parallelity task in a entirely visible room. We varied the relative distances between the objects and the observer and the separation angle between the two objects. We were able to compare our data directly with data from experiments in an environment with less monocular depth information present. We expected that in a richer environment and under less restrictive viewing conditions, the settings would deviate less from the veridical settings. However, large systematic deviations from veridical settings were found for all three tasks. The structure of these deviations was task dependent, and the structure and the deviations themselves were comparable to those obtained under more restricted circumstances. Thus, the additional information was not used effectively by the observers.

The counting abilities of children with specific language impairment: a comparison of oral and gestural tasks.

PubMed

Fazio, B B

1994-04-01

This study examined the counting abilities of preschool children with specific language impairment compared to language-matched and mental-age-matched peers. In order to determine the nature of the difficulties SLI children exhibited in counting, the subjects participated in a series of oral counting tasks and a series of gestural tasks that used an invented counting system based on pointing to body parts. Despite demonstrating knowledge of many of the rules associated with counting, SLI preschool children displayed marked difficulty in counting objects. On oral counting tasks, they showed difficulty with rote counting, displayed a limited repertoire of number terms, and miscounted sets of objects. However, on gestural counting tasks, SLI children's performance was significantly better. These findings suggest that SLI children have a specific difficulty with the rote sequential aspect of learning number words.

Reflection enhances creativity: Beneficial effects of idea evaluation on idea generation.

PubMed

Hao, Ning; Ku, Yixuan; Liu, Meigui; Hu, Yi; Bodner, Mark; Grabner, Roland H; Fink, Andreas

2016-03-01

The present study aimed to explore the neural correlates underlying the effects of idea evaluation on idea generation in creative thinking. Participants were required to generate original uses of conventional objects (alternative uses task) during EEG recording. A reflection task (mentally evaluating the generated ideas) or a distraction task (object characteristics task) was inserted into the course of idea generation. Behavioral results revealed that participants generated ideas with higher originality after evaluating the generated ideas than after performing the distraction task. The EEG results revealed that idea evaluation was accompanied with upper alpha (10-13 Hz) synchronization, most prominent at frontal cortical sites. Moreover, upper alpha activity in frontal cortices during idea generation was enhanced after idea evaluation. These findings indicate that idea evaluation may elicit a state of heightened internal attention or top-down activity that facilitates efficient retrieval and integration of internal memory representations. Copyright © 2016 Elsevier Inc. All rights reserved.

Neural correlates of the object-recall process in semantic memory.

PubMed

Assaf, Michal; Calhoun, Vince D; Kuzu, Cheedem H; Kraut, Michael A; Rivkin, Paul R; Hart, John; Pearlson, Godfrey D

2006-10-30

The recall of an object from features is a specific operation in semantic memory in which the thalamus and pre-supplementary motor area (pre-SMA) are integrally involved. Other higher-order semantic cortices are also likely to be involved. We used the object-recall-from-features paradigm, with more sensitive scanning techniques and larger sample size, to replicate and extend our previous results. Eighteen right-handed healthy participants performed an object-recall task and an association semantic task, while undergoing functional magnetic resonance imaging. During object-recall, subjects determined whether words pairs describing object features combined to recall an object; during the association task they decided if two words were related. Of brain areas specifically involved in object recall, in addition to the thalamus and pre-SMA, other regions included the left dorsolateral prefrontal cortex, inferior parietal lobule, and middle temporal gyrus, and bilateral rostral anterior cingulate and inferior frontal gyri. These regions are involved in semantic processing, verbal working memory and response-conflict detection and monitoring. The thalamus likely helps to coordinate activity of these different brain areas. Understanding the circuit that normally mediates this process is relevant for schizophrenia, where many regions in this circuit are functionally abnormal and semantic memory is impaired.

The Interactive Effects of the Availability of Objectives and/or Rules on Computer-Based Learning: A Replication.

ERIC Educational Resources Information Center

Merrill, Paul F.; And Others

To replicate and extend the results of a previous study, this project investigated the effects of behavioral objectives and/or rules on computer-based learning task performance. The 133 subjects were randomly assigned to an example-only, objective-example, rule example, or objective-rule example group. The availability of rules and/or objectives…

The highs and lows of object impossibility: effects of spatial frequency on holistic processing of impossible objects.

PubMed

Freud, Erez; Avidan, Galia; Ganel, Tzvi

2015-02-01

Holistic processing, the decoding of a stimulus as a unified whole, is a basic characteristic of object perception. Recent research using Garner's speeded classification task has shown that this processing style is utilized even for impossible objects that contain an inherent spatial ambiguity. In particular, similar Garner interference effects were found for possible and impossible objects, indicating similar holistic processing styles for the two object categories. In the present study, we further investigated the perceptual mechanisms that mediate such holistic representation of impossible objects. We relied on the notion that, whereas information embedded in the high-spatial-frequency (HSF) content supports fine-detailed processing of object features, the information conveyed by low spatial frequencies (LSF) is more crucial for the emergence of a holistic shape representation. To test the effects of image frequency on the holistic processing of impossible objects, participants performed the Garner speeded classification task on images of possible and impossible cubes filtered for their LSF and HSF information. For images containing only LSF, similar interference effects were observed for possible and impossible objects, indicating that the two object categories were processed in a holistic manner. In contrast, for the HSF images, Garner interference was obtained only for possible, but not for impossible objects. Importantly, we provided evidence to show that this effect could not be attributed to a lack of sensitivity to object possibility in the LSF images. Particularly, even for full-spectrum images, Garner interference was still observed for both possible and impossible objects. Additionally, performance in an object classification task revealed high sensitivity to object possibility, even for LSF images. Taken together, these findings suggest that the visual system can tolerate the spatial ambiguity typical to impossible objects by relying on information embedded in LSF, whereas HSF information may underlie the visual system's susceptibility to distortions in objects' spatial layouts.

Enhancing performance of a motor imagery based brain-computer interface by incorporating electrical stimulation-induced SSSEP

NASA Astrophysics Data System (ADS)

Yi, Weibo; Qiu, Shuang; Wang, Kun; Qi, Hongzhi; Zhao, Xin; He, Feng; Zhou, Peng; Yang, Jiajia; Ming, Dong

2017-04-01

Objective. We proposed a novel simultaneous hybrid brain-computer interface (BCI) by incorporating electrical stimulation into a motor imagery (MI) based BCI system. The goal of this study was to enhance the overall performance of an MI-based BCI. In addition, the brain oscillatory pattern in the hybrid task was also investigated. Approach. 64-channel electroencephalographic (EEG) data were recorded during MI, selective attention (SA) and hybrid tasks in fourteen healthy subjects. In the hybrid task, subjects performed MI with electrical stimulation which was applied to bilateral median nerve on wrists simultaneously. Main results. The hybrid task clearly presented additional steady-state somatosensory evoked potential (SSSEP) induced by electrical stimulation with MI-induced event-related desynchronization (ERD). By combining ERD and SSSEP features, the performance in the hybrid task was significantly better than in both MI and SA tasks, achieving a ~14% improvement in total relative to the MI task alone and reaching ~89% in mean classification accuracy. On the contrary, there was no significant enhancement obtained in performance while separate ERD feature was utilized in the hybrid task. In terms of the hybrid task, the performance using combined feature was significantly better than using separate ERD or SSSEP feature. Significance. The results in this work validate the feasibility of our proposed approach to form a novel MI-SSSEP hybrid BCI outperforming a conventional MI-based BCI through combing MI with electrical stimulation.

Integrating obstacle avoidance, global path planning, visual cue detection, and landmark triangulation in a mobile robot

NASA Astrophysics Data System (ADS)

Kortenkamp, David; Huber, Marcus J.; Congdon, Clare B.; Huffman, Scott B.; Bidlack, Clint R.; Cohen, Charles J.; Koss, Frank V.; Raschke, Ulrich; Weymouth, Terry E.

1993-05-01

This paper describes the design and implementation of an integrated system for combining obstacle avoidance, path planning, landmark detection and position triangulation. Such an integrated system allows the robot to move from place to place in an environment, avoiding obstacles and planning its way out of traps, while maintaining its position and orientation using distinctive landmarks. The task the robot performs is to search a 22 m X 22 m arena for 10 distinctive objects, visiting each object in turn. This same task was recently performed by a dozen different robots at a competition in which the robot described in this paper finished first.

Comparison of Direct Instruction and Problem Centered Instruction for Army Institutional Training

DTIC Science & Technology

2013-04-01

of the ALC small group classrooms and were briefed on the general research objectives. They then completed the pretest and Demographic...Findings For this research, we measured participants’ performance on well-defined (WD) tasks in terms of their score on the pretest and posttest ...WD score was 49% on the pretest and 52% on the posttest . Similarly, we measured participants’ performance on ill-defined (ID) tasks in terms of

The Effects of Feature-Based Priming and Visual Working Memory on Oculomotor Capture.

PubMed

Silvis, Jeroen D; Belopolsky, Artem V; Murris, Jozua W I; Donk, Mieke

2015-01-01

Recently, it has been demonstrated that objects held in working memory can influence rapid oculomotor selection. This has been taken as evidence that perceptual salience can be modified by active working memory representations. The goal of the present study was to examine whether these results could also be caused by feature-based priming. In two experiments, participants were asked to saccade to a target line segment of a certain orientation that was presented together with a to-be-ignored distractor. Both objects were given a task-irrelevant color that varied per trial. In a secondary task, a color had to be memorized, and that color could either match the color of the target, match the color of the distractor, or it did not match the color of any of the objects in the search task. The memory task was completed either after the search task (Experiment 1), or before it (Experiment 2). The results showed that in both experiments the memorized color biased oculomotor selection. Eye movements were more frequently drawn towards objects that matched the memorized color, irrespective of whether the memory task was completed after (Experiment 1) or before (Experiment 2) the search task. This bias was particularly prevalent in short-latency saccades. The results show that early oculomotor selection performance is not only affected by properties that are actively maintained in working memory but also by those previously memorized. Both working memory and feature priming can cause early biases in oculomotor selection.

The Effects of Feature-Based Priming and Visual Working Memory on Oculomotor Capture

PubMed Central

Silvis, Jeroen D.; Belopolsky, Artem V.; Murris, Jozua W. I.; Donk, Mieke

2015-01-01

Recently, it has been demonstrated that objects held in working memory can influence rapid oculomotor selection. This has been taken as evidence that perceptual salience can be modified by active working memory representations. The goal of the present study was to examine whether these results could also be caused by feature-based priming. In two experiments, participants were asked to saccade to a target line segment of a certain orientation that was presented together with a to-be-ignored distractor. Both objects were given a task-irrelevant color that varied per trial. In a secondary task, a color had to be memorized, and that color could either match the color of the target, match the color of the distractor, or it did not match the color of any of the objects in the search task. The memory task was completed either after the search task (Experiment 1), or before it (Experiment 2). The results showed that in both experiments the memorized color biased oculomotor selection. Eye movements were more frequently drawn towards objects that matched the memorized color, irrespective of whether the memory task was completed after (Experiment 1) or before (Experiment 2) the search task. This bias was particularly prevalent in short-latency saccades. The results show that early oculomotor selection performance is not only affected by properties that are actively maintained in working memory but also by those previously memorized. Both working memory and feature priming can cause early biases in oculomotor selection. PMID:26566137

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

Loughran, B; Singh, V; Jain, A

Purpose: Although generalized linear system analytic metrics such as GMTF and GDQE can evaluate performance of the whole imaging system including detector, scatter and focal-spot, a simplified task-specific measured metric may help to better compare detector systems. Methods: Low quantum-noise images of a neuro-vascular stent with a modified ANSI head phantom were obtained from the average of many exposures taken with the high-resolution Micro-Angiographic Fluoroscope (MAF) and with a Flat Panel Detector (FPD). The square of the Fourier Transform of each averaged image, equivalent to the measured product of the system GMTF and the object function in spatial-frequency space, wasmore » then divided by the normalized noise power spectra (NNPS) for each respective system to obtain a task-specific generalized signal-to-noise ratio. A generalized measured relative object detectability (GM-ROD) was obtained by taking the ratio of the integral of the resulting expressions for each detector system to give an overall metric that enables a realistic systems comparison for the given detection task. Results: The GM-ROD provides comparison of relative performance of detector systems from actual measurements of the object function as imaged by those detector systems. This metric includes noise correlations and spatial frequencies relevant to the specific object. Additionally, the integration bounds for the GM-ROD can be selected to emphasis the higher frequency band of each detector if high-resolution image details are to be evaluated. Examples of this new metric are discussed with a comparison of the MAF to the FPD for neuro-vascular interventional imaging. Conclusion: The GM-ROD is a new direct-measured task-specific metric that can provide clinically relevant comparison of the relative performance of imaging systems. Supported by NIH Grant: 2R01EB002873 and an equipment grant from Toshiba Medical Systems Corporation.« less

Cognitive performance and its relationship with postprandial metabolic changes after ingestion of different macronutrients in the morning.

PubMed

Fischer, K; Colombani, P C; Langhans, W; Wenk, C

2001-03-01

The effect of carbohydrate, protein and fat ingestion on simple as well as complex cognitive functions and the relationship between the respective postprandial metabolic changes and changes in cognitive performance were studied in fifteen healthy male students. Subjects were tested in three sessions, separated by 1 week, for short-term changes in blood variables, indirect calorimetry, subjective performance and different objective performance tasks using a repeated-measures counterbalanced cross-over design. Measurements were made after an overnight fast before and hourly during 3 h after test meal ingestion. Test meals consisted of either pure carbohydrates, protein or fat and were served as isoenergetic (1670 kJ) spoonable creams with similar sensory properties. Most aspects of subjective performance did not differ between test meals. For all objective tasks, however, postprandial cognitive performance was best after fat ingestion concomitant with an almost constant glucose metabolism and constant metabolic activation state measured by glucagon:insulin (G:I). In contrast, carbohydrate as well as protein ingestion resulted in lower overall cognitive performance, both together with partly marked changes in glucose metabolism and metabolic activation. They also differently affected specific cognitive functions in relation to their specific effect on metabolism. Carbohydrate ingestion resulted in relatively better short-term memory and accuracy of tasks concomitant with low metabolic activation, whereas protein ingestion resulted in better attention and efficiency of tasks concomitant with higher metabolic activation. Our findings support the concept that good and stable cognitive performance is related to a balanced glucose metabolism and metabolic activation state.

A Virtual Object-Location Task for Children: Gender and Videogame Experience Influence Navigation; Age Impacts Memory and Completion Time.

PubMed

Rodriguez-Andres, David; Mendez-Lopez, Magdalena; Juan, M-Carmen; Perez-Hernandez, Elena

2018-01-01

The use of virtual reality-based tasks for studying memory has increased considerably. Most of the studies that have looked at child population factors that influence performance on such tasks have been focused on cognitive variables. However, little attention has been paid to the impact of non-cognitive skills. In the present paper, we tested 52 typically-developing children aged 5-12 years in a virtual object-location task. The task assessed their spatial short-term memory for the location of three objects in a virtual city. The virtual task environment was presented using a 3D application consisting of a 120″ stereoscopic screen and a gamepad interface. Measures of learning and displacement indicators in the virtual environment, 3D perception, satisfaction, and usability were obtained. We assessed the children's videogame experience, their visuospatial span, their ability to build blocks, and emotional and behavioral outcomes. The results indicate that learning improved with age. Significant effects on the speed of navigation were found favoring boys and those more experienced with videogames. Visuospatial skills correlated mainly with ability to recall object positions, but the correlation was weak. Longer paths were related with higher scores of withdrawal behavior, attention problems, and a lower visuospatial span. Aggressiveness and experience with the device used for interaction were related with faster navigation. However, the correlations indicated only weak associations among these variables.

Mnemonic neuronal activity in somatosensory cortex.

PubMed Central

Zhou, Y D; Fuster, J M

1996-01-01

Single-unit activity was recorded from the hand areas of the somatosensory cortex of monkeys trained to perform a haptic delayed matching to sample task with objects of identical dimensions but different surface features. During the memory retention period of the task (delay), many units showed sustained firing frequency change, either excitation or inhibition. In some cases, firing during that period was significantly higher after one sample object than after another. These observations indicate the participation of somatosensory neurons not only in the perception but in the short-term memory of tactile stimuli. Neurons most directly implicated in tactile memory are (i) those with object-selective delay activity, (ii) those with nondifferential delay activity but without activity related to preparation for movement, and (iii) those with delay activity in the haptic-haptic delayed matching task but no such activity in a control visuo-haptic delayed matching task. The results indicate that cells in early stages of cortical somatosensory processing participate in haptic short-term memory. PMID:8927629

Next-Generation Maneuvering System with Control-Moment Gyroscopes for Extravehicular Activities Near Low-Gravity Objects

NASA Technical Reports Server (NTRS)

Carpenter, Michele; Jackson, Kimberly; Cohanim, Babak; Duda, Kevin R.; Rize, Jared; Dopart, Celena; Hoffman, Jeffrey; Curiel, Pedro; Studak, Joseph; Ponica, Dina;

Sleep Restriction during Simulated Wildfire Suppression: Effect on Physical Task Performance

PubMed Central

Vincent, Grace; Ferguson, Sally A.; Tran, Jacqueline; Larsen, Brianna; Wolkow, Alexander; Aisbett, Brad

2015-01-01

Objectives To examine the effects of sleep restriction on firefighters’ physical task performance during simulated wildfire suppression. Methods Thirty-five firefighters were matched and randomly allocated to either a control condition (8-hour sleep opportunity, n = 18) or a sleep restricted condition (4-hour sleep opportunity, n = 17). Performance on physical work tasks was evaluated across three days. In addition, heart rate, core temperature, and worker activity were measured continuously. Rate of perceived and exertion and effort sensation were evaluated during the physical work periods. Results There were no differences between the sleep-restricted and control groups in firefighters’ task performance, heart rate, core temperature, or perceptual responses during self-paced simulated firefighting work tasks. However, the sleep-restricted group were less active during periods of non-physical work compared to the control group. Conclusions Under self-paced work conditions, 4 h of sleep restriction did not adversely affect firefighters’ performance on physical work tasks. However, the sleep-restricted group were less physically active throughout the simulation. This may indicate that sleep-restricted participants adapted their behaviour to conserve effort during rest periods, to subsequently ensure they were able to maintain performance during the firefighter work tasks. This work contributes new knowledge to inform fire agencies of firefighters’ operational capabilities when their sleep is restricted during multi-day wildfire events. The work also highlights the need for further research to explore how sleep restriction affects physical performance during tasks of varying duration, intensity, and complexity. PMID:25615988

Evaluating Robotic Surgical Skills Performance Under Distractive Environment Using Objective and Subjective Measures.

PubMed

Suh, Irene H; LaGrange, Chad A; Oleynikov, Dmitry; Siu, Ka-Chun

2016-02-01

Distractions are recognized as a significant factor affecting performance in safety critical domains. Although operating rooms are generally full of distractions, the effect of distractions on robot-assisted surgical (RAS) performance is unclear. Our aim was to investigate the effect of distractions on RAS performance using both objective and subjective measures. Fifteen participants performed a knot-tying task using the da Vinci Surgical System and were exposed to 3 distractions: (1) passive distraction entailed listening to noise with a constant heart rate, (2) active distraction included listening to noise and acknowledging a change of random heart rate from 60 to 120 bpm, and (3) interactive distraction consisted of answering math questions. The objective kinematics of the surgical instrument tips were used to evaluate performance. Electromyography (EMG) of the forearm and hand muscles of the participants were collected. The median EMG frequency (EMG(fmed)) and the EMG envelope (EMG(env)) were analyzed. NASA Task Load Index and Fundamentals of Laparoscopic Surgery score were used to evaluate the subjective performance. One-way repeated analysis of variance was applied to examine the effects of distraction on skills performance. Spearman's correlations were conducted to compare objective and subjective measures. Significant distraction effect was found for all objective kinematics measures (P < .05). There were significant distraction effects for EMG measures (EMG(env), P < .004; EMG(fmed), P = .031). Significant distraction effects were also found for subjective measurements. Distraction impairs surgical skills performance and increases muscle work. Understanding how the surgeons cope with distractions is important in developing surgical education. © The Author(s) 2015.

The traveling salesman problem in surgery: economy of motion for the FLS Peg Transfer task.

PubMed

Falcone, John L; Chen, Xiaotian; Hamad, Giselle G

2013-05-01

In the Peg Transfer task in the Fundamentals of Laparoscopic Surgery (FLS) curriculum, six peg objects are sequentially transferred in a bimanual fashion using laparoscopic instruments across a pegboard and back. There are over 268 trillion ways of completing this task. In the setting of many possibilities, the traveling salesman problem is one where the objective is to solve for the shortest distance traveled through a fixed number of points. The goal of this study is to apply the traveling salesman problem to find the shortest two-dimensional path length for this task. A database platform was used with permutation application output to generate all of the single-direction solutions of the FLS Peg Transfer task. A brute-force search was performed using nested Boolean operators and database equations to calculate the overall two-dimensional distances for the efficient and inefficient solutions. The solutions were found by evaluating peg object transfer distances and distances between transfers for the nondominant and dominant hands. For the 518,400 unique single-direction permutations, the mean total two-dimensional peg object travel distance was 33.3 ± 1.4 cm. The range in distances was from 30.3 to 36.5 cm. There were 1,440 (0.28 %) of 518,400 efficient solutions with the minimized peg object travel distance of 30.3 cm. There were 8 (0.0015 %) of 518,400 solutions in the final solution set that minimized the distance of peg object transfer and minimized the distance traveled between peg transfers. Peg objects moved 12.7 cm (17.4 %) less in the efficient solutions compared to the inefficient solutions. The traveling salesman problem can be applied to find efficient solutions for surgical tasks. The eight solutions to the FLS Peg Transfer task are important for any examinee taking the FLS curriculum and for certification by the American Board of Surgery.

Distinct patterns of functional brain connectivity correlate with objective performance and subjective beliefs

PubMed Central

Barttfeld, Pablo; Wicker, Bruno; McAleer, Phil; Belin, Pascal; Cojan, Yann; Graziano, Martín; Leiguarda, Ramón; Sigman, Mariano

2013-01-01

The degree of correspondence between objective performance and subjective beliefs varies widely across individuals. Here we demonstrate that functional brain network connectivity measured before exposure to a perceptual decision task covaries with individual objective (type-I performance) and subjective (type-II performance) accuracy. Increases in connectivity with type-II performance were observed in networks measured while participants directed attention inward (focus on respiration), but not in networks measured during states of neutral (resting state) or exogenous attention. Measures of type-I performance were less sensitive to the subjects’ specific attentional states from which the networks were derived. These results suggest the existence of functional brain networks indexing objective performance and accuracy of subjective beliefs distinctively expressed in a set of stable mental states. PMID:23801762

Age-related differences in listening effort during degraded speech recognition

PubMed Central

Ward, Kristina M.; Shen, Jing; Souza, Pamela E.; Grieco-Calub, Tina M.

2016-01-01

Objectives The purpose of the current study was to quantify age-related differences in executive control as it relates to dual-task performance, which is thought to represent listening effort, during degraded speech recognition. Design Twenty-five younger adults (18–24 years) and twenty-one older adults (56–82 years) completed a dual-task paradigm that consisted of a primary speech recognition task and a secondary visual monitoring task. Sentence material in the primary task was either unprocessed or spectrally degraded into 8, 6, or 4 spectral channels using noise-band vocoding. Performance on the visual monitoring task was assessed by the accuracy and reaction time of participants’ responses. Performance on the primary and secondary task was quantified in isolation (i.e., single task) and during the dual-task paradigm. Participants also completed a standardized psychometric measure of executive control, including attention and inhibition. Statistical analyses were implemented to evaluate changes in listeners’ performance on the primary and secondary tasks (1) per condition (unprocessed vs. vocoded conditions); (2) per task (baseline vs. dual task); and (3) per group (younger vs. older adults). Results Speech recognition declined with increasing spectral degradation for both younger and older adults when they performed the task in isolation or concurrently with the visual monitoring task. Older adults were slower and less accurate than younger adults on the visual monitoring task when performed in isolation, which paralleled age-related differences in standardized scores of executive control. When compared to single-task performance, older adults experienced greater declines in secondary-task accuracy, but not reaction time, than younger adults. Furthermore, results revealed that age-related differences in executive control significantly contributed to age-related differences on the visual monitoring task during the dual-task paradigm. Conclusions Older adults experienced significantly greater declines in secondary-task accuracy during degraded speech recognition than younger adults. These findings are interpreted as suggesting that older listeners expended greater listening effort than younger listeners, and may be partially attributed to age-related differences in executive control. PMID:27556526

Autistic children and the object permanence task.

PubMed

Adrien, J L; Tanguay, P; Barthélémy, C; Martineaú, J; Perrot, A; Hameury, L; Sauvage, D

1993-01-01

Many mentally retarded autistic children can understand the concept of object permanence, but, in comparison to developmental-age matched normal children, the behavioral strategies they employ in carrying out the Casati-Lezine Object Permanence Test are deficient and lead to failure. These deficiencies appear unrelated to interference of stereotypic or other bizarre behavior in task performance. Similar problem-solving deficiencies can be found in mentally retarded children who are not autistic, suggesting that the deficiencies themselves are less related to the social-communication deficits of autistic children, but more to the general problem-solving difficulties found in children with a lower developmental quotient. Nevertheless, the qualitative analysis of results shows a tendency in autistic children, despite their better developmental level, to use less coordinated and regular sequences to solve the task than normal or mentally retarded children.

Development of online use of theory of mind during adolescence: An eye-tracking study.

PubMed

Symeonidou, Irene; Dumontheil, Iroise; Chow, Wing-Yee; Breheny, Richard

2016-09-01

We investigated the development of theory of mind use through eye-tracking in children (9-13years old, n=14), adolescents (14-17.9years old, n=28), and adults (19-29years old, n=23). Participants performed a computerized task in which a director instructed them to move objects placed on a set of shelves. Some of the objects were blocked off from the director's point of view; therefore, participants needed to take into consideration the director's ignorance of these objects when following the director's instructions. In a control condition, participants performed the same task in the absence of the director and were told that the instructions would refer only to items in slots without a back panel, controlling for general cognitive demands of the task. Participants also performed two inhibitory control tasks. We replicated previous findings, namely that in the director-present condition, but not in the control condition, children and adolescents made more errors than adults, suggesting that theory of mind use improves between adolescence and adulthood. Inhibitory control partly accounted for errors on the director task, indicating that it is a factor of developmental change in perspective taking. Eye-tracking data revealed early eye gaze differences between trials where the director's perspective was taken into account and those where it was not. Once differences in accuracy rates were considered, all age groups engaged in the same kind of online processing during perspective taking but differed in how often they engaged in perspective taking. When perspective is correctly taken, all age groups' gaze data point to an early influence of perspective information. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

Effects of spatially displaced feedback on remote manipulation tasks

NASA Technical Reports Server (NTRS)

Manahan, Meera K.; Stuart, Mark A.; Bierschwale, John M.; Hwang, Ellen Y.; Legendre, A. J.

1992-01-01

Several studies have been performed to determine the effects on computer and direct manipulation task performance when viewing conditions are spatially displaced. Whether results from these studies can be directly applied to remote manipulation tasks is quenstionable. The objective of this evaluation was to determine the effects of reversed, inverted, and inverted/reversed views on remote manipulation task performance using two 3-Degree of Freedom (DOF) hand controllers and a replica position hand controller. Results showed that trials using the inverted viewing condition showed the worst performance, followed by the inverted/reversed view and the reversed view when using the 2x3 DOF. However, these differences were not significant. The inverted and inverted/reversed viewing conditions were significantly worse than the normal and reversed viewing conditions when using the Kraft Replica. A second evaluation was conducted in which additional trials were performed with each viewing condition to determine the long term effects of spatially displaced views on task performance for the hand controllers. Results of the second evaluation indicated that there was more of a difference in performance between the perturbed viewing conditions and the normal viewing condition with the Kraft Replica than with the 2x3 DOF.

Supervision of Student Teachers: Objective Observation.

ERIC Educational Resources Information Center

Neide, Joan

1996-01-01

By keeping accurate records, student teacher supervisors can present concrete evidence about physical education student teachers' classroom performance. The article describes various ways to collect objective data, including running records, at-task records, verbal flow records, class traffic records, interaction analysis records, and global scan…

The Onset of Representation and Entry into Stage 6 of Object Permanence Development

ERIC Educational Resources Information Center

Campos, Joseph J.; Ramsay, Douglas S.

1978-01-01

Attempts to determine whether infants' performance in two search tasks is related to their entry into Stage 6 of object permanence development (thereby testing Piaget's claim that only Stage 6 infants possess the capacity for representation). (BD)

A Comparative Analysis of 2D and 3D Tasks for Virtual Reality Therapies Based on Robotic-Assisted Neurorehabilitation for Post-stroke Patients

PubMed Central

Lledó, Luis D.; Díez, Jorge A.; Bertomeu-Motos, Arturo; Ezquerro, Santiago; Badesa, Francisco J.; Sabater-Navarro, José M.; García-Aracil, Nicolás

2016-01-01

Post-stroke neurorehabilitation based on virtual therapies are performed completing repetitive exercises shown in visual electronic devices, whose content represents imaginary or daily life tasks. Currently, there are two ways of visualization of these task. 3D virtual environments are used to get a three dimensional space that represents the real world with a high level of detail, whose realism is determinated by the resolucion and fidelity of the objects of the task. Furthermore, 2D virtual environments are used to represent the tasks with a low degree of realism using techniques of bidimensional graphics. However, the type of visualization can influence the quality of perception of the task, affecting the patient's sensorimotor performance. The purpose of this paper was to evaluate if there were differences in patterns of kinematic movements when post-stroke patients performed a reach task viewing a virtual therapeutic game with two different type of visualization of virtual environment: 2D and 3D. Nine post-stroke patients have participated in the study receiving a virtual therapy assisted by PUPArm rehabilitation robot. Horizontal movements of the upper limb were performed to complete the aim of the tasks, which consist in reaching peripheral or perspective targets depending on the virtual environment shown. Various parameter types such as the maximum speed, reaction time, path length, or initial movement are analyzed from the data acquired objectively by the robotic device to evaluate the influence of the task visualization. At the end of the study, a usability survey was provided to each patient to analysis his/her satisfaction level. For all patients, the movement trajectories were enhanced when they completed the therapy. This fact suggests that patient's motor recovery was increased. Despite of the similarity in majority of the kinematic parameters, differences in reaction time and path length were higher using the 3D task. Regarding the success rates were very similar. In conclusion, the using of 2D environments in virtual therapy may be a more appropriate and comfortable way to perform tasks for upper limb rehabilitation of post-stroke patients, in terms of accuracy in order to effectuate optimal kinematic trajectories. PMID:27616992

An object-based visual attention model for robotic applications.

PubMed

Yu, Yuanlong; Mann, George K I; Gosine, Raymond G

2010-10-01

By extending integrated competition hypothesis, this paper presents an object-based visual attention model, which selects one object of interest using low-dimensional features, resulting that visual perception starts from a fast attentional selection procedure. The proposed attention model involves seven modules: learning of object representations stored in a long-term memory (LTM), preattentive processing, top-down biasing, bottom-up competition, mediation between top-down and bottom-up ways, generation of saliency maps, and perceptual completion processing. It works in two phases: learning phase and attending phase. In the learning phase, the corresponding object representation is trained statistically when one object is attended. A dual-coding object representation consisting of local and global codings is proposed. Intensity, color, and orientation features are used to build the local coding, and a contour feature is employed to constitute the global coding. In the attending phase, the model preattentively segments the visual field into discrete proto-objects using Gestalt rules at first. If a task-specific object is given, the model recalls the corresponding representation from LTM and deduces the task-relevant feature(s) to evaluate top-down biases. The mediation between automatic bottom-up competition and conscious top-down biasing is then performed to yield a location-based saliency map. By combination of location-based saliency within each proto-object, the proto-object-based saliency is evaluated. The most salient proto-object is selected for attention, and it is finally put into the perceptual completion processing module to yield a complete object region. This model has been applied into distinct tasks of robots: detection of task-specific stationary and moving objects. Experimental results under different conditions are shown to validate this model.

Hybrid reflecting objectives for functional multiphoton microscopy in turbid media

PubMed Central

Vučinić, Dejan; Bartol, Thomas M.; Sejnowski, Terrence J.

2010-01-01

Most multiphoton imaging of biological specimens is performed using microscope objectives optimized for high image quality under wide-field illumination. We present a class of objectives designed de novo without regard for these traditional constraints, driven exclusively by the needs of fast multiphoton imaging in turbid media: the delivery of femtosecond pulses without dispersion and the efficient collection of fluorescence. We model the performance of one such design optimized for a typical brain-imaging setup and show that it can greatly outperform objectives commonly used for this task. PMID:16880851

Individual differences in the perception of biological motion and fragmented figures are not correlated

PubMed Central

Jung, Eunice L.; Zadbood, Asieh; Lee, Sang-Hun; Tomarken, Andrew J.; Blake, Randolph

2013-01-01

We live in a cluttered, dynamic visual environment that poses a challenge for the visual system: for objects, including those that move about, to be perceived, information specifying those objects must be integrated over space and over time. Does a single, omnibus mechanism perform this grouping operation, or does grouping depend on separate processes specialized for different feature aspects of the object? To address this question, we tested a large group of healthy young adults on their abilities to perceive static fragmented figures embedded in noise and to perceive dynamic point-light biological motion figures embedded in dynamic noise. There were indeed substantial individual differences in performance on both tasks, but none of the statistical tests we applied to this data set uncovered a significant correlation between those performance measures. These results suggest that the two tasks, despite their superficial similarity, require different segmentation and grouping processes that are largely unrelated to one another. Whether those processes are embodied in distinct neural mechanisms remains an open question. PMID:24198799

Individual differences in the perception of biological motion and fragmented figures are not correlated.

PubMed

Jung, Eunice L; Zadbood, Asieh; Lee, Sang-Hun; Tomarken, Andrew J; Blake, Randolph

2013-01-01

WE LIVE IN A CLUTTERED, DYNAMIC VISUAL ENVIRONMENT THAT POSES A CHALLENGE FOR THE VISUAL SYSTEM: for objects, including those that move about, to be perceived, information specifying those objects must be integrated over space and over time. Does a single, omnibus mechanism perform this grouping operation, or does grouping depend on separate processes specialized for different feature aspects of the object? To address this question, we tested a large group of healthy young adults on their abilities to perceive static fragmented figures embedded in noise and to perceive dynamic point-light biological motion figures embedded in dynamic noise. There were indeed substantial individual differences in performance on both tasks, but none of the statistical tests we applied to this data set uncovered a significant correlation between those performance measures. These results suggest that the two tasks, despite their superficial similarity, require different segmentation and grouping processes that are largely unrelated to one another. Whether those processes are embodied in distinct neural mechanisms remains an open question.

Mental rotation training: transfer and maintenance effects on spatial abilities.

PubMed

Meneghetti, Chiara; Borella, Erika; Pazzaglia, Francesca

2016-01-01

One of the aims of research in spatial cognition is to examine whether spatial skills can be enhanced. The goal of the present study was thus to assess the benefit and maintenance effects of mental rotation training in young adults. Forty-eight females took part in the study: 16 were randomly assigned to receive the mental rotation training (based on comparing pairs of 2D or 3D objects and rotation games), 16 served as active controls (performing parallel non-spatial activities), and 16 as passive controls. Transfer effects to both untrained spatial tasks (testing both object rotation and perspective taking) and visual and verbal tasks were examined. Across the training sessions, the group given mental rotation training revealed benefits in the time it took to make judgments when comparing 3D and 2D objects, but their mental rotation speed did not improve. When compared with the other groups, the mental rotation training group did show transfer effects, however, in tasks other than those practiced (i.e., in object rotation and perspective-taking tasks), and these benefits persisted after 1 month. The training had no effect on visual or verbal tasks. These findings are discussed from the spatial cognition standpoint and with reference to the (rotation) training literature.

Planning sentences while doing other things at the same time: effects of concurrent verbal and visuospatial working memory load.

PubMed

Klaus, Jana; Mädebach, Andreas; Oppermann, Frank; Jescheniak, Jörg D

2017-04-01

This study investigated to what extent advance planning during sentence production is affected by a concurrent cognitive load. In two picture-word interference experiments in which participants produced subject-verb-object sentences while ignoring auditory distractor words, we assessed advance planning at a phonological (lexeme) and at an abstract-lexical (lemma) level under visuospatial or verbal working memory (WM) load. At the phonological level, subject and object nouns were found to be activated before speech onset with concurrent visuospatial WM load, but only subject nouns were found to be activated with concurrent verbal WM load, indicating a reduced planning scope as a function of type of WM load (Experiment 1). By contrast, at the abstract-lexical level, subject and object nouns were found to be activated regardless of type of concurrent load (Experiment 2). In both experiments, sentence planning had a more detrimental effect on concurrent verbal WM task performance than on concurrent visuospatial WM task performance. Overall, our results suggest that advance planning at the phonological level is more affected by a concurrently performed verbal WM task than advance planning at the abstract-lexical level. Also, they indicate an overlap of resources allocated to phonological planning in speech production and verbal WM.

Force sharing and other collaborative strategies in a dyadic force perception task

PubMed Central

Tatti, Fabio

2018-01-01

When several persons perform a physical task jointly, such as transporting an object together, the interaction force that each person experiences is the sum of the forces applied by all other persons on the same object. Therefore, there is a fundamental ambiguity about the origin of the force that each person experiences. This study investigated the ability of a dyad (two persons) to identify the direction of a small force produced by a haptic device and applied to a jointly held object. In this particular task, the dyad might split the force produced by the haptic device (the external force) in an infinite number of ways, depending on how the two partners interacted physically. A major objective of this study was to understand how the two partners coordinated their action to perceive the direction of the third force that was applied to the jointly held object. This study included a condition where each participant responded independently and another one where the two participants had to agree upon a single negotiated response. The results showed a broad range of behaviors. In general, the external force was not split in a way that would maximize the joint performance. In fact, the external force was often split very unequally, leaving one person without information about the external force. However, the performance was better than expected in this case, which led to the discovery of an unanticipated strategy whereby the person who took all the force transmitted this information to the partner by moving the jointly held object. When the dyad could negotiate the response, we found that the participant with less force information tended to switch his or her response more often. PMID:29474433

"Pre-Semantic" Cognition Revisited: Critical Differences between Semantic Aphasia and Semantic Dementia

ERIC Educational Resources Information Center

Jefferies, Elizabeth; Rogers, Timothy T.; Hopper, Samantha; Lambon Ralph, Matthew A.

2010-01-01

Patients with semantic dementia show a specific pattern of impairment on both verbal and non-verbal "pre-semantic" tasks, e.g., reading aloud, past tense generation, spelling to dictation, lexical decision, object decision, colour decision and delayed picture copying. All seven tasks are characterised by poorer performance for items that are…

Executive Functions: Formative versus Reflective Measurement

ERIC Educational Resources Information Center

Willoughby, Michael; Holochwost, Steven J.; Blanton, Zane E.; Blair, Clancy B.

2014-01-01

The primary objective of this article was to critically evaluate the routine use of confirmatory factor analysis (CFA) for representing an individual's performance across a battery of executive function tasks. A conceptual review and statistical reanalysis of N = 10 studies that used CFA methods of EF tasks was undertaken. Despite evidence of…

Pre-Service Teachers' Knowledge and Teaching Comfort Levels for Agricultural Science and Technology Objectives

ERIC Educational Resources Information Center

Wingenbach, Gary J.; White, Judith McIntosh; Degenhart, Shannon; Pannkuk, Tim; Kujawski, Jenna

2007-01-01

Self-efficacy beliefs are defined as context-specific assessments of one's competence to perform specific tasks, influence one's efforts, persistence, and resilience to succeed in a given task. Such beliefs are important determinants when considering agricultural science teachers' subject matter knowledge, teaching comfort levels, and their…

Continuous recognition of spatial and nonspatial stimuli in hippocampal-lesioned rats.

PubMed

Jackson-Smith, P; Kesner, R P; Chiba, A A

1993-03-01

The present experiments compared the performance of hippocampal-lesioned rats to control rats on a spatial continuous recognition task and an analogous nonspatial task with similar processing demands. Daily sessions for Experiment 1 involved sequential presentation of individual arms on a 12-arm radial maze. Each arm contained a Froot Loop reinforcement the first time it was presented, and latency to traverse the arm was measured. A subset of the arms were repeated, but did not contain reinforcement. Repeated arms were presented with lags ranging from 0 to 6 (0 to 6 different arm presentations occurred between the first and the repeated presentation). Difference scores were computed by subtracting the latency on first presentations from the latency on repeated presentations, and these scores were high in all rats prior to surgery, with a decreasing function across lag. There were no differences in performance following cortical control or sham surgery. However, there was a total deficit in performance following large electrolytic lesions of the hippocampus. The second experiment employed the same continuous recognition memory procedure, but used three-dimensional visual objects (toys, junk items, etc., in various shapes, sizes, and textures) as stimuli on a flat runway. As in Experiment 1, the stimuli were presented successively and latency to run to and move the object was measured. Objects were repeated with lags ranging from 0 to 4. Performance on this task following surgery did not differ from performance prior to surgery for either the control group or the hippocampal lesion group. These results provide support for Kesner's attribute model of hippocampal function in that the hippocampus is assumed to mediate data-based memory for spatial locations, but not three-dimensional visual objects.

Detecting spatial memory deficits beyond blindness in tg2576 Alzheimer mice.

PubMed

Yassine, Nour; Lazaris, Anelise; Dorner-Ciossek, Cornelia; Després, Olivier; Meyer, Laurence; Maitre, Michel; Mensah-Nyagan, Ayikoe Guy; Cassel, Jean-Christophe; Mathis, Chantal

2013-03-01

The retinal degeneration Pde6b(rd1) (rd) mutation can be a major pitfall in behavioral studies using tg2576 mice bred on a B6:SJL genetic background, 1 of the most widely used models of Alzheimer's disease. After a pilot study in wild type mice, performance of 8- and 16-month-old tg2576 mice were assessed in several behavioral tasks with the challenge of selecting 1 or more task(s) showing robust memory deficits on this genetic background. Water maze acquisition was impossible in rd homozygotes, whereas Y-maze alternation, object recognition, and olfactory discrimination were unaffected by both the transgene and the rd mutation. Spatial memory retention of 8- and 16-month-old tg2576 mice, however, was dramatically affected independently of the rd mutation when mice had to recognize a spatial configuration of objects or to perform the Barnes maze. Thus, the latter tasks appear extremely useful to evaluate spatial memory deficits and to test cognitive therapies in tg2576 mice and other mouse models bred on a background susceptible to visual impairment. Copyright © 2013 Elsevier Inc. All rights reserved.

CQPSO scheduling algorithm for heterogeneous multi-core DAG task model

NASA Astrophysics Data System (ADS)

Zhai, Wenzheng; Hu, Yue-Li; Ran, Feng

2017-07-01

Efficient task scheduling is critical to achieve high performance in a heterogeneous multi-core computing environment. The paper focuses on the heterogeneous multi-core directed acyclic graph (DAG) task model and proposes a novel task scheduling method based on an improved chaotic quantum-behaved particle swarm optimization (CQPSO) algorithm. A task priority scheduling list was built. A processor with minimum cumulative earliest finish time (EFT) was acted as the object of the first task assignment. The task precedence relationships were satisfied and the total execution time of all tasks was minimized. The experimental results show that the proposed algorithm has the advantage of optimization abilities, simple and feasible, fast convergence, and can be applied to the task scheduling optimization for other heterogeneous and distributed environment.