Entry Date:
December 26, 2006

Neural Correlates of Recognition

Principal Investigator Pawan Sinha

In conjunction with our behavioral studies of face perception with degraded images, we have attempted to determine the neural correlates of this task. Using fMRI, we have investigated neuronal responses when human observers view clear and highly degraded images of faces. We find that a specific brain region (in the fusiform gyrus) is activated when participants view clear facial images. This is not surprising, and several past studies have reported this result. What is surprising, however, is that we find that this region is also activated even when the images are so degraded that the intrinsic facial information (the pattern of eyes, nose and mouth) is entirely obliterated, so long as the surrounding contextual cues (such as the presence of a body) suggest that the degraded region might be a face. In other words, the neural circuitry in the human brain is such as to be able to use context to compensate for extreme levels of image degradations. We are following-up on these studies with single unit recordings in monkey IT cortex (in collaboration with Prof. Earl Miller) to investigate the neural encoding of facial identity in highly degraded images. Besides helping to elucidate the functional architecture of the brain's recognition machinery, these investigations are also informing our work on neurodevelopmental disorders which are characterized by difficulties in information integration.