Certain brain regions involved in planning and controlling movements show patterns of activation related specifically to action type, regardless of the body part used, a study finds. Reaching toward and grasping objects engage partially separable neural circuits in the human brain's frontal cortex and parietal cortex. However, it is unclear whether activity in these brain networks is driven by reaching or grasping behavior regardless of the body part used to perform the action. Ella Striem-Amit, Yuqi Liu, and colleagues used functional MRI to compare brain activity in seven typically developed individuals and four individuals born with severely shortened or completely absent upper limbs due to dysplasia, a condition marked by abnormal growth or development of cells within tissues or organs. While being scanned, participants reached toward and touched a foam bar with their fingers or toes, or reached toward and grasped the foam bar using their hand or foot. Action-specific regions in a wide network of frontoparietal association sensorimotor cortices involved in planning and controlling movements were activated in both typically developed individuals and individuals with dysplasia. Further, this brain network showed different activity for reaching versus grasping, regardless of the body part used. According to the authors, the findings suggest that the functions of many regions in the human brain emerge based on innate constraints, regardless of motor or sensory experience in early development.
Article #20-17789: "Evidence for an effector-independent action system from people born without hands," by Yuqi Liu, Gilles Vannuscorps, Alfonso Caramazza and Ella Striem-Amit.
MEDIA CONTACTS: Ella Striem-Amit, Georgetown University Medical Center, Washington, DC; tel: 857-205-8023; e-mail: Ella.StriemAmit@georgetown.edu; Yuqi Liu, Georgetown University Medical Center, Washington, DC; tel: 302-509-1173; e-mail: yl1179@georgetown.edu
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Journal
Proceedings of the National Academy of Sciences