Inhibition and Disinhibition

When we are talking of a person as “losing control” we usually talk of an excess of behavior. We may talk of someone who is intoxicated as losing control when they show an exaggerated emotional response with little provocation. A person who shows this kind of behavioral excess is referred to as being disinhibited.

Disinhibition is simply defined as lack of restraint in responding to a situation. A patient exhibiting disinhibition reacts impulsively and often inappropriately.

An individual who has problems with disinhibition may daydream during lectures, or respond impulsively rather than thoughtfully to a social cue.

Problems with disinhibition may also have an effect on a person’s ability to use effective strategies to perform a task.

In general, behaviors and ideation related to disinhibition may be traceable to general difficulties in impulse control that are a large element in attention deficit hyperactivity disorder (ADHD) Opens in new window.

As opposed to being disinhibited, there is another sense in which we lose control of our own behavior, and this is manifested by an inability to initiate behavior, which is referred to as inhibition.

Strangely, a patient with frontal pathology can, at various times, be both inhibited and disinhibited. Thus, they may have difficulty getting going or initiating a behavior spontaneously (inhibited), but may also be goaded into some automatic routine of behavior in a disinhibited manner and then not be able to stop when it is appropriate (disinhibition).

An example of this was evident in a recent dementia patient at an emergency department who, according to MRI brain scan, showed evidence of atrophy in the frontal lobes.

On assessment, the patient lacked any flexibility Opens in new window on a number of tasks and had difficulty in producing a response on others.

When asked to produce words beginning with “F” (time allowed, 1 minute) this conservatively dressed older lady produced only three words (inhibited), one of which was a rude four-letter one (disinhibited).

She then proceeded to hug and kiss the author fervently when it was time for her to go (disinhibited). Overall, the problem is one of control.

Impulsivity is associated with disinhibition and is strongly but not exclusively related to orbital pathology. This phenomenon may have something in common with distractibility Opens in new window in the sense that external stimuli may draw the exclusive attention of the subject.

Impulsivity Opens in new window is well illustrated by go-no go tasks (Drewe, 1975). In these tasks, patients are typically asked to make one response to one signal and an absence of response to another signal.

For example, the patient is instructed to squeeze or tap the examiner’s hand when the examiner says “stop” but must withhold a response to the word “go”. There is a tendency in this instance to make the error of squeezing in response to the word “go”, when a response should be withheld.

  1. Bechara, A. Damasio, A. R., Damasio, H., & Anderson, S. W. (1994). Insensitivity to future consequences following damage to human prefrontal cortex. Cognition, 50, 7-15.
  2. Anderson, P. (2008). Towards a developmental model of executive function. In V. Anderson, R. Jacobs, & P. Anderson (Eds.), Executive functions and the frontal lobes (pp. 3-22). New York, NY:Taylor and Francis Group.
  3. Aron, A. R. (2007). The neural basis of inhibition in cognitive control. Neuroscientist, 13, 214-228.
  4. Aron, A. R. (2011). From reactive to proactive and selective control: Developing a richer model for stopping inappropriate responses. Biological Psychiatry, 69, e55-e68.