Cortical mechanisms of cognition in primates.
Researchers in my laboratory study the brain mechanisms of cognition by recording from single neurons in the cerebral cortex of behaving monkeys. Our interests include spatial vision, visual pattern recognition, and executive control.
Spatial vision encompasses a host of skills including the ability to see how parts are arranged in an object. Object-centered spatial vision is critical to various human activities including reading, which hinges on appreciating the arrangement of letters in a word. We study the neural underpinnings of object-centered spatial vision by recording from frontal and parietal neurons in monkeys trained to remember and respond to particular locations on objects.
Visual pattern recognition depends critically on inferotemporal cortex (IT), an area in which neurons respond selectively to particular visual images. We study the neural basis of pattern recognition by recording from single IT neurons while monkeys discriminate among complex patterns. One aim of current work is to establish a direct link between the behavioral effect of previously having seen an image (priming) and the effect on neural activity in IT (response suppression).
Executive control–deciding what to do moment by moment–depends on considering the consequences associated with particular actions and selecting the action that give rises to the best outcome. We study the neural mechanisms of executive control by recording from neurons in frontal cortex while monkeys choose among actions that will result in different rewards or penalties. Neurons in some areas signal the emotional impact of an anticipated outcome (positive for reward and negative for penalty). Neuronal activity in other areas rises or falls according to how motivated the monkey is (regardless of whether motivation is driven by the promise of a reward or the threat of a penalty). We are interested in working out the neural processing stages by which emotional evaluation of consequences associated with actions gives rise to motivated behavior.
Baker, C.I., Behrmann, M., and Olson, C.R. Impact of visual discrimination training on the representation of parts and wholes in monkey inferotemporal cortex. Nature Neuroscience 5:1210-1216, 2002.
Roesch, M.R., and Olson, C.R. Neuronal activity related to reward value and motivation in primate frontal cortex. Science 304: 307-310, 2004.
Roesch, M.R., and Olson, C.R. Neuronal activity in primate orbitofrontal cortex reflects the value of time. J. Neurophysiol. 94: 2451-2471, 2005.
Moorman, D., and Olson, C.R. Impact of learning on representation of object-centered space in macaque supplementary eye field. J. Neurophysiol. 97:2159-2173, 2007.
McMahon, D.B.T., and Olson, C.R. Repetition suppression in monkey inferotemporal cortex: Relation to behavioral priming. J. Neurophysiol 97: 3532-3543, 2007.