Activity in primary visual cortex predicts performance in a visual detection task

Visual attention can affect both neural activity and behavior in humans. To quantify possible links between the two, we measured activity in early vis ual cortex (V1, V2 and V3) during a challenging pattern-detection task. Act ivity was dominated by a large response that was independent of the presenc e or absence of the stimulus pattern. The measured activity quantitatively predicted the subject's pattern-detection performance: when activity was gr eater, the subject was more likely to correctly discern the presence or abs ence of the pattern. This stimulus-independent activity had several charact eristics of visual attention, suggesting that attentional mechanisms modula te activity in early visual cortex, and that this attention-related activit y strongly influences performance.