Allocentric representations for target memory and reaching in human cortex. Issue 1 (17th October 2019)

• Record Type: Journal Article
• Authors: Chen, Ying; Crawford, J. Douglas
• Editors: Miller, Michael B.; Kingstone, Alan
• Is Part Of: Annals of the New York Academy of Sciences. Volume 1464:Issue 1(2020)
• Page Start: 142
• Page End: 155
• Publication Date: 2019-10-17
• Subjects: allocentric coding -- directional selectivity -- reach -- fMRI; Medical sciences -- Periodicals; Medicine -- Periodicals; Science -- Periodicals; 610
• DOI: 10.1111/nyas.14261
• Languages: English
• ISSNs: 0077-8923

Abstract

Abstract: The use of allocentric cues for movement guidance is complex because it involves the integration of visual targets and independent landmarks and the conversion of this information into egocentric commands for action. Here, we focus on the mechanisms for encoding reach targets relative to visual landmarks in humans. First, we consider the behavioral results suggesting that both of these cues influence target memory, but are then transformed—at the first opportunity—into egocentric commands for action. We then consider the cortical mechanisms for these behaviors. We discuss different allocentric versus egocentric mechanisms for coding of target directional selectivity in memory (inferior temporal gyrus versus superior occipital gyrus) and distinguish these mechanisms from parieto‐frontal activation for planning egocentric direction of actual reach movements. Then, we consider where and how the former allocentric representations of remembered reach targets are converted into the latter egocentric plans. In particular, our recent neuroimaging study suggests that four areas in the parietal and frontal cortex (right precuneus, bilateral dorsal premotor cortex, and right presupplementary area) participate in this allo‐to‐ego conversion. Finally, we provide a functional overview describing how and why egocentric and landmark‐centered representations are segregated early in the visual system, but then reintegrated in the parieto‐frontal cortex for action. Abstract : The use of allocentric cues for movement guidance is complex because it involves the integration of visual targets and independent landmarks and the conversion of this information into egocentric commands for action. The focus of the review will be on the neural mechanisms of allocentric versus egocentric representations of reach targets in memory in humans.