Mind-wandering

Mind-wandering (sometimes referred to as task unrelated thought) is the experience of thoughts not remaining on a single topic for a long period of time, particularly when people are not engaged in an attention-demanding task. It is the topic of research in the study of attention and consciousness, as it relates to attentional lapses, or digression due to lack of focus on the task in hand.

Mind-wandering tends to occur during driving, reading and other activities where vigilance may be low. In these situations, people report having no memory of what happened in the surrounding environment while pre-occupied 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 thinking is not focused on the task in hand, the brain processes both task relevant and unrelated sensory information in a less detailed manner.

Mind-wandering appears to be both a stable trait of people and a transient state. Studies have linked performance problems in the laboratory and in daily life. Mind-wandering is also intimately linked to states of affect; studies indicate that task unrelated thought is common in states of low or depressed mood. Mind-wandering is also common when drunk through the consumption of alcohol.

It is common during mind-wandering to engage in mental time travel—the consideration of personally relevant events from the past and the anticipation of events in the future. Poet Joseph Brodsky described it as a “psychological Sahara,” a cognitive desert “that starts right in your bedroom and spurns the horizon.” The hands of the clock seem to stop; the stream of consciousness slows to a drip. We want to be anywhere but here.

Studies have demonstrated a prospective bias to spontaneous thought because individuals tend to engage in more future than past related thoughts during mind-wandering.