AbstractThe continuous performance test (CPT) is a behavioural assessment of attentional modulation of the motor system (Rosvold et al., 1956). It has firstly been used in patients with brain injuries and then applied to assess sustained attention and vigilance in epilepsy, brain tumor, dementia, schizophrenia and other psychiatric diseases, such as attention-deficit hyperactivity disorder (ADHD) and anxiety disorders (Rosvold et al., 1956; Honey et al., 2005; Kanaka et al., 2008). There are several versions of the test. For instance, the X-CPT version presents randomly different stimuli and subjects are asked to push a button only on presentation of the target stimuli (X). In the AX-CPT version, the subjects are required to push the button only when a cue stimulus is presented before the target one (A before X). The following items are measured for the X and AX tasks: omission errors (number of times subjects fail to respond to target stimulation), commission errors (number of times subjects respond to non target stimulation), average reaction time and coefficient of variance for both correct reactions and commission errors (Suwa et al., 2004). There are other versions, such as the CPT-not X version where the subjects are asked not to push a button when the target stimulus (X) is presented; the Degraded Stimuli (DS)-CPT (Nuechterlein, 1983); the CPT playing card version (Rutschmann et al., 1977); and the CPT Identical Pairs version (Cornblatt et al., 1988), which is a more difficult task prepared to assess high risk population. Interestingly, the Identical Pairs version has been included in the Matrics neurocognitive assessment, a consensus cognitive battery for clinical trials of cognition in schizophrenia (Nuechterlein et al., 2008).