Temporal features of the degree effect in self-relevance: neural correlates

The present study investigated neural correlates underlying the psychological processing of the extent of self-relevance. Event-related potentials were recorded for distracting names different in extent of self-relevance while subjects performed a three-stimulus oddball task. The results showed larger amplitudes and prolonged latencies for high self-relevant than for moderate self-relevant, low self-relevant and non-self-relevant names at P2 component. Furthermore, N2 amplitudes were decreased for the high self-relevant and moderate self-relevant names than for the low self-relevant and non-self-relevant names. Moreover, the high self-relevant names elicited larger positive deflections than the moderate self-relevant names which, in turn, elicited larger positive deflections than the low self-relevant and non-self-relevant names at both P3 and 440-540 ms intervals. Additionally, the peak latencies of P3 were prolonged during the high self-relevant and moderate self-relevant than during the low self-relevant and non-self-relevant conditions. Therefore, in addition to replicating the classic self-relevant effect, the present study extended previous studies by showing a clear self-relevant degree effect, with high self-relevant stimuli processed more preferentially in the brain relative to those low in self-relevance.