Fifth, we examined microstimulation-induced effects on RT distributions. For each session, we collapsed trials (correct and error) across coherence

levels and computed the cumulative RT distributions, separately for the two choices and microstimulation conditions (Figure S4). For each choice, we computed the difference in cumulative RT distributions between trials with and without microstimulation. The microstimulation effect on the RT distribution was measured as the average difference across sessions, separately for the two choices. For model predictions, choice and RT data were simulated with session-specific fitting parameters and with trial numbers Palbociclib purchase for the different coherence × direction conditions matched to the experimental data. Simulated data were analyzed in the same way as the experimental data. Mean and standard deviation of the simulated difference in cumulative RT distribution were estimated using bootstrap methods. We thank Takahiro Doi, Matt Nassar, and Yin Li for helpful comments and Jean Zweigle for animal care. This work was supported

by NIH K99–EY018042 and ARRA supplement (L.D.) and R01–EY015260 (J.I.G.) from the National Eye Institute. “
“During natural vision, many stimuli simultaneously Protease Inhibitor Library ic50 activate our visual system. In primary visual cortex, two separate stimuli typically activate two separate groups of neurons. These separate groups of neurons send anatomical connections that converge onto postsynaptic neurons in higher visual areas (Fries, 2009). Through this convergence, the postsynaptic neurons can respond to either one of the two stimuli. Yet, if one of those stimuli is behaviorally relevant, it Oxymatrine dominates the activity of the postsynaptic neurons at the expense of the irrelevant stimulus (Moran and Desimone, 1985; Treue and Maunsell, 1996; Reynolds et al., 1999). This effect can be explained as a selective enhancement of synaptic

gain of the relevant input (Reynolds et al., 1999). A candidate mechanism for this enhancement needs to fulfill at least the following criteria: (1) it has to be specific for the relevant subset of synaptic inputs versus the irrelevant subset, even though the two sets are probably interspersed on a postsynaptic neuron; (2) it has to be flexible to select different subsets of synapses as the relevant stimulus undergoes changes; and (3) it has to be able to switch within a few hundred milliseconds from strengthening one set of synapses to another set, because switching attention from one stimulus to another affects the activity of the postsynaptic neurons and behavior at this time scale (Busse et al., 2008). To meet these requirements, we and others have proposed that the selective enhancement of relevant synaptic input is implemented by the selective rhythmic synchronization of the neuronal target group with the relevant input (Fries, 2005, 2009; Börgers and Kopell, 2008).