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Author Salzer, Y.; Friedman, J.
Title Reaching trajectories unravel modality-dependent temporal dynamics of the automatic process in the Simon task: a model-based approach Type Journal Article
Year 2020 Publication Psychological Research Abbreviated Journal Psychol Res
Volume 84 Issue 6 Pages (up) 1700-1713
Keywords
Abstract The Simon effect represents a phenomenon in which the location of the stimuli affects the speed and accuracy of the response, despite being irrelevant for the task demands. This is believed to be due to an automatic activation of a response corresponding to the location of the stimuli, which conflicts with the controlled decision process based on relevant stimuli features. Previously, differences in the nature of the Simon effect (i.e., the pattern of change of the effect across the distribution of response times) between visual and somatosensory stimuli were reported. We hypothesize that the temporal dynamics of visual and somatosensory automatic and controlled processes vary, thus driving the reported behavioral differences. While most studies have used response times to study the underlying mechanisms involved, in this study we had participants reach out to touch the targets and recorded their arm movements using a motion capture system. Importantly, the participants started their movements before a final decision was made. In this way, we could analyze the movements to gain insights into the competition between the automatic and controlled processes. We used this technique to describe the results in terms of a model assuming automatic activation due to location-based evidence, followed by inhibition. We found that for the somatosensory Simon effect, the decay of the automatic process is significantly slower than for the visual Simon effect, suggesting quantitative differences in this automatic process between the visual and somatosensory modalities.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0340-0727 ISBN Medium
Area Expedition Conference
Notes PMID:30980236 Approved no
Call Number Serial 97
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Author Raveh, E.; Friedman, J.; Portnoy, S.
Title Evaluation of the effects of adding vibrotactile feedback to myoelectric prosthesis users on performance and visual attention in a dual-task paradigm Type Journal Article
Year 2018 Publication Clinical Rehabilitation Abbreviated Journal Clin Rehabil
Volume 99 Issue 11 Pages (up) 2263-2270
Keywords
Abstract Objective: To evaluate the effects of adding vibrotactile feedback to myoelectric prosthesis users on the performance time and visual attention in a dual-task paradigm.

Design: A repeated-measures design with a counterbalanced order of two conditions.

Setting: Laboratory setting.

Subjects: Transradial amputees using a myoelectric prosthesis with normal or corrected eyesight (N=12, median age=65 ± 13 years). Exclusion criteria were orthopedic or neurologic problems.

Interventions: Subjects performed grasping tasks with their prosthesis, while controlling a virtual car on a road with their intact hand. The dual task was performed twice: with and without vibrotactile feedback.

Main measures: Performance time of each of the grasping tasks and gaze behavior, measured by the number of times the subjects shifted their gaze toward their hand, the relative time they applied their attention to the screen, and percentage of error in the secondary task.

Results: The mean performance time was significantly shorter (P=0.024) when using vibrotactile feedback (93.2 ± 9.6 seconds) compared with the performance time measured when vibrotactile feedback was not available (107.8 ± 20.3seconds). No significant differences were found between the two conditions in the number of times the gaze shifted from the screen to the hand, in the time the subjects applied their attention to the screen, and in the time the virtual car was off-road, as a percentage of the total game time

(51.4 ± 15.7 and 50.2 ± 19.5, respectively).

Conclusion: Adding vibrotactile feedback improved performance time during grasping in a dual-task paradigm. Prosthesis users may use vibrotactile feedback to perform better during daily tasks, when multiple cognitive demands are present.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0269-2155 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number Penn State @ write.to.jason @ Serial 89
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Author Raveh, E.; Portnoy, S.; Friedman, J.
Title Myoelectric Prosthesis Users Improve Performance Time and Accuracy Using Vibrotactile Feedback When Visual Feedback Is Disturbed Type Journal Article
Year 2018 Publication Archives of Physical Medicine and Rehabilitation Abbreviated Journal Arch Phys Med Rehabil
Volume 99 Issue 11 Pages (up) 2263-2270
Keywords Amputation; Prosthesis; Rehabilitation; Sensory feedback; Visual feedback
Abstract OBJECTIVE: To evaluate the effects of adding vibrotactile feedback (VTF) in myoelectric prosthesis users during performance of a functional task when visual feedback is disturbed. DESIGN: A repeated-measures design with a counter-balanced order of 3 conditions. SETTING: Laboratory setting. PARTICIPANTS: Transradial amputees using a myoelectric prosthesis with normal or corrected eyesight (N=12, median age 65+/-13y). Exclusion criteria were orthopedic or neurologic problems. INTERVENTIONS: All participants performed the modified Box and Blocks Test, grasping and manipulating 16 blocks over a partition using their myoelectric prosthesis. This was performed 3 times: in full light, in a dark room without VTF, and in a dark room with VTF. MAIN OUTCOME MEASURES: Performance time, that is, the time needed to transfer 1 block, and accuracy during performance, measured by number of empty grips, empty transitions with no block and block drops from the hand. RESULTS: Significant differences were found in all outcome measures when VTF was added, with improved performance time (4.2 vs 5.3s) and a reduced number of grasping errors (3.0 vs 6.5 empty grips, 1.5 vs 4 empty transitions, 2.0 vs 4.5 block drops). CONCLUSIONS: Adding VTF to myoelectric prosthesis users has positive effects on performance time and accuracy when visual feedback is disturbed.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0003-9993 ISBN Medium
Area Expedition Conference
Notes PMID:29935153 Approved no
Call Number Serial 96
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Author Zopf, R.; Friedman, J.; Williams, M.A.
Title The plausibility of visual information for hand ownership modulates multisensory synchrony perception Type Journal Article
Year 2015 Publication Abbreviated Journal Experimental Brain Research
Volume 233 Issue 8 Pages (up) 2311-2321
Keywords Multisensory perception; Temporal synchrony perception; Virtual hand; Body representations; Body ownership; Sensory predictions
Abstract We are frequently changing the position of our bodies and body parts within complex environments. How does the brain keep track of one’s own body? Current models of body ownership state that visual body ownership cues such as viewed object form and orientation are combined with multisensory information to correctly identify one’s own body, estimate its current location and evoke an experience of body ownership. Within this framework, it may be possible that the brain relies on a separate perceptual analysis of body ownership cues (e.g. form, orientation, multisensory synchrony). Alternatively, these cues may interact in earlier stages of perceptual processing—visually derived body form and orientation cues may, for example, directly modulate temporal synchrony perception. The aim of the present study was to distinguish between these two alternatives. We employed a virtual hand set-up and psychophysical methods. In a two-interval force-choice task, participants were asked to detect temporal delays between executed index finger movements and observed movements. We found that body-specifying cues interact in perceptual processing. Specifically, we show that plausible visual information (both form and orientation) for one’s own body led to significantly better detection performance for small multisensory asynchronies compared to implausible visual information. We suggest that this perceptual modulation when visual information plausible for one’s own body is present is a consequence of body-specific sensory predictions.
Address
Corporate Author Thesis
Publisher Springer Berlin Heidelberg Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0014-4819 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number Serial 78
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Author Dempsey-Jones, H.; Wesselink, D.B.; Friedman, J.; Makin, T.R.
Title Organized Toe Maps in Extreme Foot Users Type Journal Article
Year 2019 Publication Cell Reports Abbreviated Journal Cell Reports
Volume 28 Issue 11 Pages (up) 2748-2756.e4
Keywords
Abstract Although the fine-grained features of topographic maps in the somatosensory cortex can be shaped by everyday experience, it is unknown whether behavior can support the expression of somatotopic maps where they do not typically occur. Unlike the fingers, represented in all primates, individuated toe maps have only been found in non-human primates. Using 1-mm resolution fMRI, we identify organized toe maps in two individuals born without either upper limb who use their feet to substitute missing hand function and even support their profession as foot artists. We demonstrate that the ordering and structure of the artists’ toe representation mimics typical hand representation. We further reveal “hand-like” features of activity patterns, not only in the foot area but also similarly in the missing hand area. We suggest humans may have an innate capacity for forming additional topographic maps that can be expressed with appropriate experience.
Address
Corporate Author Thesis
Publisher Elsevier Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2211-1247 ISBN Medium
Area Expedition Conference
Notes doi: 10.1016/j.celrep.2019.08.027 Approved no
Call Number Serial 99
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