Mind-wandering

Mind-wandering (sometimes referred to as task unrelated thought, or, colloquially, autopilot) is the experience of thoughts not remaining on a single topic for a long period of time, particularly when people are engaged in an attention-demanding task. Mind-wandering (sometimes referred to as task unrelated thought, or, colloquially, autopilot) is the experience of thoughts not remaining on a single topic for a long period of time, particularly when people are engaged in an attention-demanding task. Mind-wandering tends to occur during driving, reading and other activities where vigilance may be low. In these situations, people do not remember what happened in the surrounding environment because they are preoccupied with their thoughts. This is known as the decoupling hypothesis. Studies using event-related potentials (ERPs) have quantified the extent that mind-wandering reduces the cortical processing of the external environment. When thoughts are unrelated to the task at hand, the brain processes both task-relevant and unrelated sensory information in a less detailed manner. Mind-wandering appears to be a stable trait of people and a transient state. Studies have linked performance problems in the laboratory and in daily life. Mind-wandering has been associated with possible car accidents. Mind-wandering is also intimately linked to states of affect. Studies indicate that task-unrelated thoughts are common in people with low or depressed mood. Mind-wandering also occurs when a person is intoxicated via the consumption of alcohol. Studies have demonstrated a prospective bias to spontaneous thought because individuals tend to engage in more future than past related thoughts during mind-wandering. The default mode network is thought to be involved in mind-wandering and internally directed thought, although recent work has challenged this assumption The history of mind-wandering research dates back to 18th century England. British philosophers struggled to determine whether mind-wandering occurred in the mind or if an outside source caused it. In 1921, Varendonck published The Psychology of Day-Dreams, in which he traced his ''trains of thoughts' to identify their origins, most often irrelevant external influences'. Wallas (1926) considered mind-wandering as an important aspect of his second stage of creative thought – incubation. It wasn't until the 1960s that the first documented studies were conducted on mind-wandering. John Antrobus and Jerome L. Singer developed a questionnaire and discussed the experience of mind-wandering. This questionnaire, known as the Imaginal Processes Inventory (IPI), provides a trait measure of mind-wandering and it assesses the experience on three dimensions: how vivid the person's thoughts are, how many of those thoughts are guilt- or fear-based, and how deep into the thought a person goes. As technology continues to develop, psychologists are starting to use functional magnetic resonance imaging to observe mind-wandering in the brain and reduce psychologists' reliance on verbal reports. Jonathan Smallwood and colleagues popularized mind-wandering using thought sampling and questionnaires. Mind-wandering is studied using experience sampling either online or retrospectively. One common paradigm within which to study mind-wandering is the SART (sustained attention to response) task. In a SART task there are two categories of words. One of the categories are the target words. In each block of the task a word appears for about 300 ms, there will be a pause and then another word. When a target word appears the participant hits a designated key. About 60% of the time after a target word a thought probe will appear to gauge whether thoughts were on task. If participants were not engaged in the task they were experiencing task-unrelated thoughts (TUTs), signifying mind-wandering. Another task to judge TUTs is the experience sampling method (ESM). Participants carry around a personal digital assistant (PDA) that signals several times a day. At the signal a questionnaire is provided. The questionnaire questions vary but can include: (a) whether or not their minds had wandered at the time of the (b) what state of control they had over their thoughts and (c) about the content of their thoughts. Questions about context are also asked to measure the level of attention necessary for the task. One process used was to give participants something to focus on and then at different times ask them what they were thinking about. Those who were not thinking about what was given to them were considered 'wandering'. Another process was to have participants keep a diary of their mind-wandering. Participants are asked to write a brief description of their mind-wandering and the time in which it happened. These methodologies are improvements on past methods that were inconclusive. Mind-wandering is important in understanding how the brain produces what William James called the train of thought and the stream of consciousness. This aspect of mind-wandering research is focused on understanding how the brain generates the spontaneous and relatively unconstrained thoughts that are experienced when the mind wanders. One candidate neural mechanism for generating this aspect of experience is a network of regions in the frontal and parietal cortex known as the default network. This network of regions is highly active even when participants are resting with their eyes closed suggesting a role in generating spontaneous internal thoughts. One relatively controversial result is that periods of mind-wandering are associated with increased activation in both the default and executive system a result that implies that mind-wandering may often be goal oriented. It is commonly assumed that the default mode network is known to be involved during mind-wandering. The default mode network is active when a person is not focused on the outside world and the brain is at wakeful rest because experiences such as mind-wandering and daydreaming are common in this state. It is also active when the individual is thinking about others, thinking about themselves, remembering the past, and planning for the future. However, recent studies show that signals in the default mode network provide information regarding patterns of detailed experience in active tasks states. These data suggest that the relationship between the default mode network and mind-wandering remains a matter of conjecture. In addition to neural models, computational models of consciousness based on Bernard Baars' Global Workspace theory suggest that mind-wandering, or 'spontaneous thought' may involve competition between internally and externally generated activities attempting to gain access to a limited capacity central network.