Faces, Attention, and the Temporal Lobe
We perceive the world as a space of objects. We can recognize these objects with an ease belying the daunting complexity of the computational challenges involved. But, as I will argue in my talk, evolution has presented us with a unique model system to decipher the mechanisms of object recognition. The temporal lobes of macaque monkeys contain neural machinery to support face recognition, consisting of a fixed number of discrete patches of face-selective cortex. The three main organizing features of this system, concentration of cells encoding the same complex object category into modules, spatial separation of modules, and integration of modules into a network, make it possible to break down the process of face recognition into its components. In the second part of my talk I will turn to something completely different, attention. Using fMRI in macaque monkeys, we found a network of areas to be modulated by attention in motion-discrimination task, included a hitherto unsuspected region within inferotemporal cortex, PITd. We then targeted PITd for electrophysiological recordings and electrical microstimulation in different tasks to learn about its role in sensory information processing and spatial attention. I will discuss the somewhat radical conclusion we arrived at, namely that PITd may constitute a region for attentional control.