Expectations Attenuate the Negative Influence of Neural Adaptation on the Processing of Novel Stimuli: ERP Evidence

When processing repeated stimuli, the neural response is attenuated (i.e., neural adaptation) and performance seems to be facilitated; however, this neural adaptation negatively influences the subsequent processing of novel stimuli. The present study was designed to test whether and how temporal expectations reduce neural adaptation and attenuate the negative influence of neural adaptation on subsequent novel problem solving. Temporal expectations were experimentally manipulated by asking participants to solve a novel problem following three to five repeated problems, generating the expectation of repeated events in the first three serial positions as well as that of novel events in the fourth to sixth serial positions. Compared to the first occurrence, repeated problems evoked more negative deflections, including greater N1, lower P2 and greater LNC amplitudes, regardless of whether participants expected a repeated or novel event; however, the mean amplitudes of the P2 and LNC were smaller in the latter condition. These results show neural adaptation during processing of repeated stimuli and demonstrate that neural adaptation is reduced when a novel event is expected. Regarding the novel events, the conflict monitoring- and resolution-related N400, P600 and LNC amplitudes decreased with decreased neural adaptation. These results indicate that the expectation of novel events attenuate the negative influence of neural adaptation on the subsequent processing of novel events. This study provides new insight into alleviating the constraints imposed by frequently used knowledge on the processing of novel stimuli.