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Smallwood (2013) made important contributions to the science of mind wandering by distinguishing between 2 aspects of the mind-wandering experience: (a) how the mind wanders, which entails the process of maintaining the continuity of a mind-wandering episode, and (b) why the mind wanders, which refers to those mechanisms that lead to the occurrence of a mind-wandering episode. This new process-occurrence framework offers a way to compare and contrast existing theories of mind wandering and highlights key questions to be addressed in future work; however, we suggest that in characterizing one of the core mechanisms of mind wandering, Smallwood conflated the occurrence of a phenomenon with its explanation. Specifically, the occurrence of perceptual decoupling (i.e., that mind wandering is associated with reduced attention to external stimuli) was conflated with an explanation for its occurrence (i.e., in order to insulate the internal train of thought). Disentangling the theory of perceptual decoupling raises questions regarding both its role in insulating the internal train of thought in mind wandering and its unique theoretical contributions to the how/process of mind wandering., (PsycINFO Database Record (c) 2013 APA, all rights reserved.)

Although consciousness can be brought to bear on both perceptual and internally generated information, little is known about how these different cognitive modes are coordinated. Here we show that between-participant variance in thoughts unrelated to the task being performed (known as task unrelated thought, TUT) is associated with longer response times (RT) when target presentation occurs during periods when baseline Pupil Diameter (PD) is increased. As behavioral interference due to high baseline PD can reflect increased tonic activity in the norepinephrine system (NE), these results might implicate high tonic NE activity in the facilitation of TUTs. Based on these findings, it is hypothesised that high tonic mode NE leads to a generalised de-amplification of task relevant information that prioritses internally generated thought and insulates it from the potentially disruptive events taking place in the external environment.

The N400 is an event-related potential (ERP) component that is elicited by semantically meaningful stimuli; one of its defining characteristics is that it is amplified for sentence completions that are semantically unexpected or incongruous with the preceding context. Some prior reports using visual sentence reading paradigms have suggested that there may also be a Cz-centered P400 (a P400cz) that is also responding to semantic congruity manipulations, distinct from the classic Pz-centered N400 (the N400pz). In the present experiment, sentences were presented visually one word at a time, and half of the sentences ended with a semantically incongruent ending. High-density 129-channel event-related potential data were recorded from 26 participants. A combination of temporo-spatial principal components analysis (PCA) and item averaging was applied to decompose the waveforms. The presence of the P400cz was confirmed. The P400cz was much more sensitive to congruity and somewhat more sensitive to cloze probability than the N400pz. The separation of the N400 semantic effect into these two portions is consistent with both MEG studies and intracranial studies. The data suggest that the N400pz has its major source in the bilateral anterior medial temporal lobe (AMTL) whereas it is suggested that the P400cz has its major source in the medial parietal region. It is further suggested that whereas the N400pz process appears to be semantic in nature, some prior reports suggest that the P400cz reflects a general sequential expectancy system., (Copyright © 2010 Elsevier B.V. All rights reserved.)

The current study sought to uncover how temporal information is represented in our knowledge about routine events. In Experiment 1 we collected norming data on eight routines taken from Galambos (1983). In Experiment 2 participants were presented with two actions of varying distance from a routine and asked "Are the actions in the correct order?". We found that a number of variables interact with distance, including action position, routine familiarity, and experimental block. These data suggest that sometimes participants are faster when the actions are far apart in the routine, while at other times they are faster when actions are closer together, providing evidence for both distance and reverse-distance effects, respectively. A model is presented to help interpret these data in which temporal information for routine events is both: (1) coarsely coded, and processed by an estimation mechanism; and (2) represented serially, and processed by a scanning mechanism.