Attentional Changes in Either Criterion or Sensitivity Are Associated with Robust Modulations in Lateral Prefrontal Cortex.

Visual attention is associated with neuronal changes across the brain, and these widespread signals are generally assumed to underlie a unitary mechanism of attention. However, using signal detection theory, attention-related effects on performance can be partitioned into changes in either the subject's criterion or sensitivity. Neuronal modulations associated with only sensitivity changes were previously observed in visual cortex, raising questions about which structures mediate attention-related changes in criterion and whether individual neurons are involved in multiple components of attention. Here, we recorded from monkey lateral prefrontal cortex (LPFC) and found that, in contrast to visual cortex, neurons in LPFC changed their firing rates, pairwise correlation, and Fano factor when subjects changed either their criterion or their sensitivity. These results indicate that attention-related neuronal modulations in separate brain regions are not a monolithic signal and instead can be linked to distinct behavioral changes.