Colinear facilitation promotes reliability of single-cell responses in catstriate cortex

Behavior is controlled by neural activity in the brain. The final outcome o f this neural control may critically depend on the firing reliability of in dividual neurons. A nearly constant, proportional relationship is usually f ound between the response mean and response variance. Here we asked whether lateral interactions within striate cortex that modulate response magnitud e also proportionately modify the response variance of cortical neurons. In many cases, response variability depended on stimulus organization: discre te flankers colinearly placed well outside the neuron's receptive field inc reased response magnitude without a proportional increase in variance, thus improving the neuron's response reliability. Since colinear flanker facili tation is often seen near the neuron's firing threshold, increased response reliability for weak stimuli may contribute to enhancing perceptual salien cy.