Medial axis shape coding in macaque inferotemporal cortex.
The basic, still unanswered question about visual object representation is this: what specific information is encoded by neural signals? Theorists have long predicted that neurons would encode medial axis or skeletal object shape, yet recent studies reveal instead neural coding of boundary or surface shape. Here, we addressed this theoretical/experimental disconnect, using adaptive shape sampling to demonstrate explicit coding of medial axis shape in high-level object cortex (macaque monkey inferotemporal cortex or IT). Our metric shape analyses revealed a coding continuum, along which most neurons represent a configuration of both medial axis and surface components. Thus, IT response functions embody a rich basis set for simultaneously representing skeletal and external shape of complex objects. This would be especially useful for representing biological shapes, which are often characterized by both complex, articulated skeletal structure and specific surface features.
Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, 725 N Wolfe Street, Baltimore, MD 21205, USA.
Chia-Chun
CC
Hung
Eric T
ET
Carlson
Charles E
CE
Connor
D000200:Action Potentials / Q000502:physiology; D000818:Animals; D005260:Female; D005556:Form Perception / Q000502:physiology*; D008253:Macaca mulatta; D008297:Male; D009474:Neurons / Q000502:physiology*; D010364:Pattern Recognition, Visual / Q000502:physiology; D010775:Photic Stimulation; D013702:Temporal Lobe / Q000502:physiology*; D014795:Visual Pathways / Q000502:physiology*