Study: Inner Speech Can Improve Verbal Ability

Researchers used a new term ‘anendophasia’  to describe a lack of inner speech that varies from individual to individual.

The word “Anendophasia” can be broken into – an (lack) + endo (inner) + phasia (speech). This word has its root in  Greek that is phasia (aphasia, paraphasia, etc.)

Inner speech refers to the act of silently talking to yourself, which is universal. Inner speech has a complex relationship with the cognitive processes of humans. Most people experience this phenomenon so it was assumed common for everyone but the study showed some people are lacking this inner speech from a moderate level to complete absence of it.

These individuals tend to have lower performance on tasks that include verbal working memory and rhyme judgments. However, it does not affect cognitive processes like task-switching abilities.

The said research focused on investing in the behavioural implications of anendophasia. It includes four separate experiments as follows:

1. Rhyme Judgments: In this experiment, participants were shown pairs of images and instructed to indicate if their names rhyme or not. This task was based on verbal processing.
2. Verbal Working Memory: This was assessed memory for sets of words, either orthographically similar and phonologically different or phonologically similar and orthographically different. 
3. Task Switching: This refers to switching between adding and subtracting numbers.
4. Same/different Judgments: This experiment used black silhouettes of three cats and three dogs. The participants have to make physical identification judgments and category judgments.

Two groups of participants were assessed for the research based on their self-reported levels of inner speech. One group includes individuals who reported low inner speech (N = 46) and showed poorer performance in verbal working memory tasks than the group of individuals with high inner speech (N = 47).

Characteristics of the participants like age, gender, dyslexia, education, and first language were the same for both groups.

The result suggests that inner speech may play an important role in our ability to store and modify information.

In the experiment of rhyme judgment, individuals with low inner speech faced more challenges. From this result, researchers assumed that inner speech may increase the linguistic modification required for such tasks. Also, inner speech may support a range of verbal activities like reading, creative writing etc.

However, all cognitive functions that involve verbal processing are not affected by the levels of inner speech. Also task-switching performance where participants had to shift attention between tasks did not show different results between the two groups.

The study does not find any significant categorical effects on perceptual judgments regarding inner speech.

Limitation :

The research completely relied upon subjective experience.