Achievement

Trainee Steinmetz's research exemplifies the interplay between computational and experimental approaches in our program. He and co-mentor Boahen used a computational model to examine the hypothesis that a special class of neurotransmitter receptors (NMDA receptors) could mediate gain modulation of neural activitiy during spatial attention as revealed in neuronal recording studies conducted by Steinmetz in his primary mentor's laboratory. They designed a large-scale model with two simulated cortical areas, each containing an excitatory and an inhibitory population of spiking neurons. One area fed back activation to NMDA synapses of neurons in the other areas. They found that this feedback could account for the particular multiplicative gain modulations observed in the neuronal recordings. Based on these results they predict that blocking NMDA receptors in extrastriate visual cortex would eliminate attention-driven firing rate modulations; Steinmetz is testing this in current studies.