Open Access. Powered by Scholars. Published by Universities.®
Articles 1 - 3 of 3
Full-Text Articles in Medicine and Health Sciences
Two Distinct Ipsilateral Cortical Representations For Individuated Finger Movements., Jörn Diedrichsen, Tobias Wiestler, John W Krakauer
Two Distinct Ipsilateral Cortical Representations For Individuated Finger Movements., Jörn Diedrichsen, Tobias Wiestler, John W Krakauer
Brain and Mind Institute Researchers' Publications
Movements of the upper limb are controlled mostly through the contralateral hemisphere. Although overall activity changes in the ipsilateral motor cortex have been reported, their functional significance remains unclear. Using human functional imaging, we analyzed neural finger representations by studying differences in fine-grained activation patterns for single isometric finger presses. We demonstrate that cortical motor areas encode ipsilateral movements in 2 fundamentally different ways. During unimanual ipsilateral finger presses, primary sensory and motor cortices show, underneath global suppression, finger-specific activity patterns that are nearly identical to those elicited by contralateral mirror-symmetric action. This component vanishes when both motor cortices are …
Prefrontal Neurons Of Opposite Spatial Preference Display Distinct Target Selection Dynamics., Therese Lennert, Julio C Martinez-Trujillo
Prefrontal Neurons Of Opposite Spatial Preference Display Distinct Target Selection Dynamics., Therese Lennert, Julio C Martinez-Trujillo
Brain and Mind Institute Researchers' Publications
Neurons in the primate dorsolateral prefrontal cortex (dlPFC) of one hemisphere are selective for the location of attended targets in both visual hemifields. Whether dlPFC neurons with selectivity for opposite hemifields directly compete with each other for target selection or instead play distinct roles during the allocation of attention remains unclear. We explored this issue by recording neuronal responses in the right dlPFC of two macaques while they allocated attention to a target in one hemifield and ignored a distracter on the opposite side. Forty-nine percent of the recorded neurons were target location selective. Neurons selective for contralateral targets (58%) …
Decoding The Neural Mechanisms Of Human Tool Use., Jason P Gallivan, D Adam Mclean, Kenneth F Valyear, Jody C Culham
Decoding The Neural Mechanisms Of Human Tool Use., Jason P Gallivan, D Adam Mclean, Kenneth F Valyear, Jody C Culham
Brain and Mind Institute Researchers' Publications
Sophisticated tool use is a defining characteristic of the primate species but how is it supported by the brain, particularly the human brain? Here we show, using functional MRI and pattern classification methods, that tool use is subserved by multiple distributed action-centred neural representations that are both shared with and distinct from those of the hand. In areas of frontoparietal cortex we found a common representation for planned hand- and tool-related actions. In contrast, in parietal and occipitotemporal regions implicated in hand actions and body perception we found that coding remained selectively linked to upcoming actions of the hand whereas …