Dr. Paul Bogdan, Duke University, will lecture "Big and Small Stimulus Representations in the Ventral Stream."
Abstract: One of the oldest questions in the neurosciences is whether the brain encodes information in a localized or distributed fashion. The present research studies this topic while considering that the scale of a neural representation may depend on the area where it is encoded and the type of content being encoded. Using available data from participants (N = 60) who repeatedly viewed different images of objects, we performed an original form of representational similarity analysis (RSA). The analyses revealed that perceptual information across the brain is primarily encoded via local representations, whereas semantic information is more often encoded as representations spanning multiple regions. In this respect, the inferior temporal lobe particularly stood out as it encoded semantic information nearly totally in a distributed fashion - i.e., the fusiform face area, parahippocampal place area, and other areas coordinated to produce wide-scale population codes representing individual objects. In turn, a dissociation emerged in the ventral stream, such that object processing seems to transition from primarily local perceptual coding in the occipital lobe to distributed semantic coding in the inferior temporal lobe. Altogether, these findings inform theories on the unique nature of the inferior temporal lobe and more broadly shed light on the computational architecture of object processing in the brain.
Zoom Meeting ID: 719 402 7586
Passcode: 448953
