Attenuated Face And Non-Face Processing During Mind Wandering:Evidence From An ERP Study

Mind Wandering(MW)refers to the phenomenon in which people’s attention is shifted from an ongoing task and/or from events in the external environment to self-generated thoughts and feelings.As an important part of the human consciousness experience,it is particularly important to explore the neural mechanism of the occurrence of MW.Previous studies have found out that MW not only attenuates the processing of external perceptual information,but also affects cognitive analysis and assessment of stimuli.However,it is not clear whether stimulus itself will affect its extent of attenuation during MW,or it is related to task paradigm.The Sustained Attention to Response Task(SART)was hereby adopted and event-related potential technique was put into use,which was of high temporal resolution to track the time course of MW,and to explore whether MW affected the processing of face and non-face(building)pictures.Each participant completed two SARTs respectively,being instructed to respond via button press to high-frequency non-targets and withhold their response to low-frequency targets.Moreover,participants were asked to report their attention state when each probe appeared.Marvelous significance has been attached to the behavioral and ERP response to the seven non-targets(face or non-face pictures)preceding probes and targets.The results were as follows:1)Behavioral results showed that mind wandering rates or no-go error rates did not differ significantly between faces and buildings.2)There was pre-error speeding of MW.Specifically,RTs for the non-target trials preceding targets error was significantly faster than those preceding correct responses,regardless of types of stimulus.3)ERP results revealed that there was no significant difference in the PI amplitude elicited by the faces or buildings preceding on-task reports(or a correctly withheld response to targets)and off-task reports(or a response error to targets).However,the latency of P1 component elicited by faces or buildings preceding targets error was significantly longer than preceding accurate responses.4)Faces elicited N170,while N170 was not elicited by buildings.Furthermore,there was no significant difference in the N170 amplitude elicited by the faces or buildings preceding on-task reports(or a correctly withheld response to targets)and off-task reports(or a response error to targets).5)P3 amplitude elicited by faces or buildings preceding off-task reports significantly declined than on-task reports,while P3 amplitude elicited by faces or buildings did not differ significantly between the two objective indicators.In summary,face processing is special,and the N170 component is not affected by MW.Moreover,the results indicated that off-task reports could be associated with an attenuated processing of face and non-face pictures,and the effect presented in the late but not in the early ERP response to face or non-face pictures.Thus,the impact of MW on cognitive analysis of stimulus is mainly related to task paradigm rather than stimulus itself,which supports attentional decoupling hypothesis.In short,the attentional decoupling hypothesis can be extended directly from the meaningless stimulus to a meaningful one.