There is a common saying for expressing familiarity with something. It refers to our hands, and strangely enough, in English, one says to know something like the back of the hand, whereas in other cultures, for example, Italy, Spain and France, the same expression is with the palm. Previous behavioural data have suggested that our ability to visually discriminate a right from a left hand is influenced by perspective. This behavioural finding has remained without neurophysiological counterparts. We used an implicit motor imagery task in which 30 right-handed subjects were asked to decide whether a picture portrayed a right rather than a left hand during an fMRI event-related experiment. Both views (back and palm) were used, and the hands were rotated by 45° in 8 possible angles. We replicated previous behavioural evidence by showing faster reaction times for the back-view and view-specific interaction effects with the angle of rotation: for the back view, the longest RTs were with the hand facing down at 180°; for the palm view, the longest RTs were at 90° with the hand pointing away from the midline. In addition, the RTs were particularly faster for back views of the right hand. fMRI measurements revealed a stronger BOLD signal increase in left premotor and parietal cortices for stimuli viewed from the palm, whereas back-view stimuli were associated with stronger occipital activations, suggesting a view-specific cognitive strategy: more visually oriented for the back of the hand; more in need of the support of a motoric imagery process for the palms. Right-hand back views were associated with comparatively smaller BOLD responses, attesting, together with the faster reaction times, to the lesser need for neural labour because of greater familiarity with that view of the hand. These differences suggest the existence of brain-encoded, view-dependent representations of body segments

Zapparoli, L., Invernizzi, P., Gandola, M., Berlingeri, M., De Santis, A., Zerbi, A., et al. (2014). Like the back of the (right) hand? A new fMRI look on the hand laterality task. EXPERIMENTAL BRAIN RESEARCH, 232(12), 3873-3895 [10.1007/s00221-014-4065-z].

Like the back of the (right) hand? A new fMRI look on the hand laterality task

ZAPPAROLI, LAURA;BERLINGERI, MANUELA;PAULESU, ERALDO
2014

Abstract

There is a common saying for expressing familiarity with something. It refers to our hands, and strangely enough, in English, one says to know something like the back of the hand, whereas in other cultures, for example, Italy, Spain and France, the same expression is with the palm. Previous behavioural data have suggested that our ability to visually discriminate a right from a left hand is influenced by perspective. This behavioural finding has remained without neurophysiological counterparts. We used an implicit motor imagery task in which 30 right-handed subjects were asked to decide whether a picture portrayed a right rather than a left hand during an fMRI event-related experiment. Both views (back and palm) were used, and the hands were rotated by 45° in 8 possible angles. We replicated previous behavioural evidence by showing faster reaction times for the back-view and view-specific interaction effects with the angle of rotation: for the back view, the longest RTs were with the hand facing down at 180°; for the palm view, the longest RTs were at 90° with the hand pointing away from the midline. In addition, the RTs were particularly faster for back views of the right hand. fMRI measurements revealed a stronger BOLD signal increase in left premotor and parietal cortices for stimuli viewed from the palm, whereas back-view stimuli were associated with stronger occipital activations, suggesting a view-specific cognitive strategy: more visually oriented for the back of the hand; more in need of the support of a motoric imagery process for the palms. Right-hand back views were associated with comparatively smaller BOLD responses, attesting, together with the faster reaction times, to the lesser need for neural labour because of greater familiarity with that view of the hand. These differences suggest the existence of brain-encoded, view-dependent representations of body segments
Articolo in rivista - Articolo scientifico
Implicit motor imagery, Hand laterality task, fMRI, BOLD, Activation
English
2014
232
12
3873
3895
none
Zapparoli, L., Invernizzi, P., Gandola, M., Berlingeri, M., De Santis, A., Zerbi, A., et al. (2014). Like the back of the (right) hand? A new fMRI look on the hand laterality task. EXPERIMENTAL BRAIN RESEARCH, 232(12), 3873-3895 [10.1007/s00221-014-4065-z].
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/10281/52744
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