Detection of a novelty event in the identification of faces in a passive VEP task

The degree of severity of several psychopathologies coming along with cognitive deficits often impedes the adequate execution of complex cognitive tasks, demanding for objective analysis of cognitive function in an easy-to-follow paradigm for uncooperative patients. The broad availability of electroencephalography (EEG) provides an auspicious base for the development of a fast and reliable tool for the objective diagnosis of pathological cognitive limitations. In the development of the paradigm and follow-up data analysis, we focussed on the objective assessment of the most common cognitive deficits in psychopathological disorders, i.e., limitations in working-memory span and the corresponding loss of attentional resources as well as deficits in facial recognition, contributing to severe social cuts. In a passive face recognition task, we monitored the N170 component of late visual evoked potentials (VEP) in healthy subjects for establishing a methodological base for the diagnostics of cognitive deficits in patients. In line with our preliminary work, we were able to demonstrate a loss of phasic coherence in the single-trial analysis of subsequent visual stimuli during the repetitive face presentation. The novelty event however involuntarily captures attentional resources, resulting in an afresh increase in intertrial phase coherence. These results provide a new viable methodology for accessing the novelty-effect in cognitive deficit patients using a passive visual ERP paradigm of involuntary attentional guidance and habituation.