Exaggerated object affordance and absent automatic inhibition in alien hand syndrome.

Patients with alien hand syndrome (AHS) experience making apparently deliberate and purposeful movements with their hand against their will. However, the mechanisms contributing to these involuntary actions remain poorly understood. Here, we describe two experimental investigations in a patient with...

Full description

Bibliographic Details
Main Authors: McBride, J, Sumner, P, Jackson, SR, Bajaj, N, Husain, M
Format: Journal article
Language:English
Published: 2013
_version_ 1797064480825278464
author McBride, J
Sumner, P
Jackson, SR
Bajaj, N
Husain, M
author_facet McBride, J
Sumner, P
Jackson, SR
Bajaj, N
Husain, M
author_sort McBride, J
collection OXFORD
description Patients with alien hand syndrome (AHS) experience making apparently deliberate and purposeful movements with their hand against their will. However, the mechanisms contributing to these involuntary actions remain poorly understood. Here, we describe two experimental investigations in a patient with corticobasal syndrome (CBS) with alien hand behaviour in her right hand. First, we show that responses with the alien hand are made significantly more quickly to images of objects which afford an action with that hand compared to objects which afford an action with the unaffected hand. This finding suggests that involuntary grasping behaviours in AHS might be due to exaggerated, automatic motor activation evoked by objects which afford actions with that limb. Second, using a backwards masked priming task, we found normal automatic inhibition of primed responses in the patient's unaffected hand, but importantly there was no evidence of such suppression in the alien limb. Taken together, these findings suggest that grasping behaviours in AHS may result from exaggerated object affordance effects, which might potentially arise from disrupted inhibition of automatically evoked responses.
first_indexed 2024-03-06T21:14:56Z
format Journal article
id oxford-uuid:3f73ecfa-5c0c-42a4-aab9-5b16d02bfb7d
institution University of Oxford
language English
last_indexed 2024-03-06T21:14:56Z
publishDate 2013
record_format dspace
spelling oxford-uuid:3f73ecfa-5c0c-42a4-aab9-5b16d02bfb7d2022-03-26T14:32:06ZExaggerated object affordance and absent automatic inhibition in alien hand syndrome.Journal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:3f73ecfa-5c0c-42a4-aab9-5b16d02bfb7dEnglishSymplectic Elements at Oxford2013McBride, JSumner, PJackson, SRBajaj, NHusain, MPatients with alien hand syndrome (AHS) experience making apparently deliberate and purposeful movements with their hand against their will. However, the mechanisms contributing to these involuntary actions remain poorly understood. Here, we describe two experimental investigations in a patient with corticobasal syndrome (CBS) with alien hand behaviour in her right hand. First, we show that responses with the alien hand are made significantly more quickly to images of objects which afford an action with that hand compared to objects which afford an action with the unaffected hand. This finding suggests that involuntary grasping behaviours in AHS might be due to exaggerated, automatic motor activation evoked by objects which afford actions with that limb. Second, using a backwards masked priming task, we found normal automatic inhibition of primed responses in the patient's unaffected hand, but importantly there was no evidence of such suppression in the alien limb. Taken together, these findings suggest that grasping behaviours in AHS may result from exaggerated object affordance effects, which might potentially arise from disrupted inhibition of automatically evoked responses.
spellingShingle McBride, J
Sumner, P
Jackson, SR
Bajaj, N
Husain, M
Exaggerated object affordance and absent automatic inhibition in alien hand syndrome.
title Exaggerated object affordance and absent automatic inhibition in alien hand syndrome.
title_full Exaggerated object affordance and absent automatic inhibition in alien hand syndrome.
title_fullStr Exaggerated object affordance and absent automatic inhibition in alien hand syndrome.
title_full_unstemmed Exaggerated object affordance and absent automatic inhibition in alien hand syndrome.
title_short Exaggerated object affordance and absent automatic inhibition in alien hand syndrome.
title_sort exaggerated object affordance and absent automatic inhibition in alien hand syndrome
work_keys_str_mv AT mcbridej exaggeratedobjectaffordanceandabsentautomaticinhibitioninalienhandsyndrome
AT sumnerp exaggeratedobjectaffordanceandabsentautomaticinhibitioninalienhandsyndrome
AT jacksonsr exaggeratedobjectaffordanceandabsentautomaticinhibitioninalienhandsyndrome
AT bajajn exaggeratedobjectaffordanceandabsentautomaticinhibitioninalienhandsyndrome
AT husainm exaggeratedobjectaffordanceandabsentautomaticinhibitioninalienhandsyndrome