Visual attention can affect both neural activity and behavior in humans.
To quantify possible links between the two, we measured activity in early
visual cortex (V1, V2 and V3) during a challenging pattern-detection task.
Activity was dominated by a large response that was independent of the presence
or absence of the stimulus pattern. The measured activity quantitatively predicted
the subject's pattern-detection performance: when activity was greater, the
subject was more likely to correctly discern the presence or absence of the
pattern. This stimulus-independent activity had several characteristics of
visual attention, suggesting that attentional mechanisms modulate activity
in early visual cortex, and that this attention-related activity strongly
influences performance.
