Timing and magnitude of frontal activity differentiates refixation and anti-saccade performance. 
EEG data were recorded while 10 subjects generated refixation saccades towards a visual target and antisaccades away from a visual cue.  Theoretically, the same basic neural circuitry supports refixation and correct anti-saccade performances, with additional activity in primarily dorsolateral prefrontal cortex circuitry supporting antisaccade-associated inhibitory processes.  Analyses demonstrated that sensory registration of visual stimuli is similar for refixation and anti-saccade conditions.  Increased frontal brain activity at 5 and 15 Hz was observed preceding correct antisaccades when compared to refixation saccades.  These analyses provide specific information suggesting that 160-60 ms before saccade generation is the critical period for response inhibition.