Neuropsychological tests are designed to target specific cognitive functions and used for cognitive evaluation in disorders such as dementias, psychoses; however, numerous cognitive subcomponents are involved in each test. We wanted to decompose the cognitive components by recording event related potentials (ERPs) during administration of computerized versions of three frontal executive function tests, go-nogo, continuous performance task (CPT) and Stroop. Through the choice of three tests targeting complementary cognitive domains we aimed to define the ERP correlates of response inhibition, sustained attention and resistance to interference in the same subject population. 32 channel-EEG was recorded continuously from 24 subjects. ERPs were averaged and N100, P100, N200, P300 peak amplitudes and latencies were measured. For Stroop, 550ms-950ms time period was divided into 100ms intervals and mean amplitudes were measured. N200 was pronounced and the P300 had a central maximum in the nogo trials in go-nogo and CPT. All amplitudes were larger in CPT compared to go-nogo. In Stroop, a left lateralized negativity around 400ms and a parietoccipital negative difference in the 650-750ms time window were observed in incongruent trials. Our results show that go-nogo and CPT have similar P3 topographies probably reflecting the common response inhibition component and the observation of a general increase in amplitudes in CPT might be reflecting the additional sustained attention component of this test. Although Stroop seems to include a similar response inhibition effect, the characteristics of the ERPs show that the resistance to interference effect in Stroop involves a more complex, lateralized activation pattern than the simpler response inhibition tasks.