Mind-wandering
Mind-wandering is broadly defined as thoughts that are task-unrelated and stimulus-independent. This can take the form of three different subtypes: positive constructive daydreaming, guilty fear of failure, and poor attentional control.
A common understanding of mind-wandering 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.
One context in which mind-wandering often occurs is driving. This is because driving under optimal conditions becomes an almost automatic activity that can require minimal use of the task positive network, the brain network that is active when one is engaged in an attention-demanding activity. In situations where vigilance is low, 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 have shown that mind-wandering reduces the brain's processing of external information. 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. Nondirective meditation methods, like Acem-meditation, utilize the spontaneous mind-wandering tendencies of the mind. Therefore, such techniques may be less demanding and more effective than meditation methods that apply concentration.
History
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 considered mind-wandering as an important aspect of his second stage of creative thought – incubation. It was not 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, 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.
Research methods
and colleagues popularized the study of 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.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, signifying mind-wandering.
Another task to judge TUTs is the experience sampling method. Participants carry around a personal digital assistant that signals several times a day. At the signal a questionnaire is provided. The questionnaire questions vary but can include: whether or not their minds had wandered at the time of the what state of control they had over their thoughts and 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.
Neuroscience
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 medial frontal and medial parietal cortex known as the default mode 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. This data suggests 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.
Individual differences
There are individual differences in some aspects of mind-wandering between older and younger adults. Although older adults reported less mind-wandering, these older participants showed the same amount of mind-wandering as younger adults. There were also differences in how participants responded to an error.After an error, older adults took longer to return focus back to the task when compared with younger adults. It is possible that older adults reflect more about an error due to conscientiousness. Research has shown that older adults tend to be more conscientious than young adults. Personality can also affect mind-wandering.
People that are more conscientious are less prone to mind-wandering. Being more conscientious allows people to stay focused on the task better which causes fewer instances of mind-wandering. Differences in mind-wandering between young and older adults may be limited because of this personality difference.
Mental disorders such as ADHD are linked to mind-wandering. Seli et al. found that spontaneous mind-wandering, the uncontrolled or unwarranted shifting of attention, is a characteristic of those who have ADHD. However, they note that deliberate mind-wandering, or the purposeful shifting of one's attention to different stimuli, is not a consistent characteristic of having ADHD.
Franklin et al. arrived at similar conclusions; they had college students take multiple psychological evaluations that gauge ADHD symptom strength. Then, they had the students read a portion of a general science textbook. At various times and at random intervals throughout their reading, participants were prompted to answer a question that asked if their attention was either on task, slightly on task, slightly off task, or off task prior to the interruption.
In addition, they were asked if they were aware, unaware, or neither aware nor unaware of their thoughts as they read. Lastly, they were tasked to press the space bar if they ever caught themselves mind-wandering. For a week after these assessments, the students answered follow-up questions that also gauged mind-wandering and awareness.
This study's results revealed that students with higher ADHD symptomology showed less task-oriented control than those with lower ADHD symptomology. Additionally, those with lower ADHD symptomology were more likely to engage in useful or deliberate mind-wandering and were more aware of their inattention. One of the strengths of this study is that it was performed in both lab and daily-life situations, giving it broad application.
Mind-wandering in and of itself is not necessarily indicative of attention deficiencies. Studies show that humans typically spend 25-50% of their time thinking about thoughts irrelevant to their current situations.
In many disorders it is the regulation of the overall amount of mind-wandering that is disturbed, leading to increased distractibility when performing tasks. Additionally, the contents of mind-wandering is changed; thoughts can be more negative and past-oriented, particularly unstable or self-centered.