Context-Dependent Duration Signals in the Primate Prefrontal Cortex.

The activity of some prefrontal (PF) cortex neurons distinguishes short from long time intervals. Here, we examined whether this property reflected a general timing mechanism or one dependent on behavioral context. In one task, monkeys discriminated the relative duration of 2 stimuli; in the other, they discriminated the relative distance of 2 stimuli from a fixed reference point.

The relation of cognitive load and pupillary unrest.

Objective: This study examines the relationship between pupillary unrest (PU) and cognitive load.

Background: PU represents a measure of reduced central nervous tonic arousal (sleepiness). A loss of tonic arousal can be associated with difficulties in maintaining the required level of performance.