Do we all have a 'little voice' in our head?

Inner speech is the “little voice” in our head — although some rightly argue that it can get loud indeed. Inner speech constitutes the covert behaviour of talking to ourselves in silence. We can also talk to ourselves out loud when alone, known as “self-talk.” Inner speech is always verbal, can be condensed (abbreviated, like isolated words) or expanded (like full sentences) and can be spontaneous or voluntary. Seeing mental images in one’s head or experiencing emotions or sensations, such as happiness and hunger, do not represent inner speech instances.

We talk to ourselves for many reasons, including planning, problem-solving, decision-making, remembering, replaying past conversations or mentally anticipating future ones, calculating and reading. A significant portion of inner speech is about us (our emotions, appearance, goals, health, career, etc.), suggesting that it serves an important self-reflective function aimed at understanding ourselves. Although talking to ourselves is largely healthy, it becomes detrimental when we engage in rumination — that is, a repetitive, self-critical and uncontrollable internal dialogue. Rumination increases the likelihood of experiencing depression and social anxiety.

Debates playing out on social media such as YouTube and Facebook have sparked a controversy regarding whether one can have no inner speech at all. Some people have claimed that they do not have an inner voice — a condition called anendophasia.

A recent study titled, “Not everybody has an inner voice: Behavioral consequences of anendophasia,” published in Psychological Science in 2024, examined possible consequences of rarely engaging in inner speech and found lower working memory performance — for instance, having difficulties verbally recalling a list of grocery items. Critics have pointed out that participants had reduced inner speech as opposed to a genuine lack of inner speech. In Descriptive Experience Sampling studies, volunteers get randomly interrupted in their natural environment by the sound of a beeper and are asked to report whatever they were internally experiencing when beeped. Typically, inner speech is present about a quarter of the time when participants are beeped; those reporting experiencing no inner speech at all are very rare.

One important possibility is that people who report having no inner speech do experience it but either are unaware of their inner verbal experiences or are misinterpreting them as being something else, such as sensations or mental images. After all, we would expect anendophasia to result in a host of debilitating deficits, including poor judgment and planning, memory problems and self-control issues. We would also predict self-awareness difficulties, such as being unable to label one’s current emotions or remember one’s past. Indeed, patients who lose their inner voice following a stroke report experiencing such impairments.

Perhaps anendophasia really exists and people with no inner speech have found ways to compensate in non-verbal ways. One strategy to settle the controversy could be to record spontaneous brain activity occurring in anendophasia participants. One brain area gets reliably activated when people engage in inner speech: the left inferior frontal gyrus (LIFG). The expectation would be to observe an absence of LIFG activity in such participants. Observing LIFG activity would challenge the existence of anendophasia.

Dr. Alain Morin, PhD, is a professor in Mount Royal’s Department of Psychology.