★A paper by Researcher Kota Otani, Assistant Professor Ryuta Kuwamizu, and colleagues on inner speech in young children was published in Acta Psychologica
A study by Researcher Kota Otani and Assistant Professor Ryuta Kuwamizu of ARIHHP, University of Tsukuba, and their colleagues has been published in the international journal Acta Psychologica. A research news release on the study has also been issued by the University of Tsukuba.
In this study, the researchers investigated the development of “inner speech”—language used silently in the mind and therefore difficult to observe directly—using a simple mental counting task in children aged 3 to 6 years. Participants were asked to count from 1 to 5 silently in their minds.
The results showed that silent counting became increasingly stable with age. Around age 5, children were also more likely to count entirely in their minds without relying on overt speech or movements of their fingers or lips.
These findings demonstrate that a simple and familiar activity—counting numbers—may provide an objective way to capture developmental changes in inner speech, even in young children who may have difficulty verbally reporting their internal experiences.
In addition, a presentation related to this study, “How can we measure children’s inner speech? Examining the objective measurement and developmental trajectory of inner speech using a mental counting task,” received an Excellent Presentation Award at the 89th Annual Convention of the Japanese Psychological Association.
For further details, please see the original article and the University of Tsukuba Research News.
In this study, the researchers investigated the development of “inner speech”—language used silently in the mind and therefore difficult to observe directly—using a simple mental counting task in children aged 3 to 6 years. Participants were asked to count from 1 to 5 silently in their minds.
The results showed that silent counting became increasingly stable with age. Around age 5, children were also more likely to count entirely in their minds without relying on overt speech or movements of their fingers or lips.
These findings demonstrate that a simple and familiar activity—counting numbers—may provide an objective way to capture developmental changes in inner speech, even in young children who may have difficulty verbally reporting their internal experiences.
In addition, a presentation related to this study, “How can we measure children’s inner speech? Examining the objective measurement and developmental trajectory of inner speech using a mental counting task,” received an Excellent Presentation Award at the 89th Annual Convention of the Japanese Psychological Association.
For further details, please see the original article and the University of Tsukuba Research News.
【Publication Information】
Title: The developmental origin of inner speech: Evidence from a mental counting task in 3- to 6-year-old children
Authors: Kota Otani, Ryoichi Watanabe, Ryuta Kuwamizu, Nozomi Yamamoto, Yusuke Moriguchi
Journal: Acta Psychologica, 270, 107716 (2026).
DOI: 10.1016/j.actpsy.2026.107716
Title: The developmental origin of inner speech: Evidence from a mental counting task in 3- to 6-year-old children
Authors: Kota Otani, Ryoichi Watanabe, Ryuta Kuwamizu, Nozomi Yamamoto, Yusuke Moriguchi
Journal: Acta Psychologica, 270, 107716 (2026).
DOI: 10.1016/j.actpsy.2026.107716
University of Tsukuba Research News
Counting to Five Reveals How Children’s “Inner Speech” Develops
Counting to Five Reveals How Children’s “Inner Speech” Develops
【Award】
Presentation: How can we measure children’s inner speech? Examining the objective measurement and developmental trajectory of inner speech using a mental counting task
Authors: Kota Otani, Ryoichi Watanabe, Ryuta Kuwamizu, Nozomi Yamamoto, Yusuke Moriguchi
Award: Excellent Presentation Award, 89th Annual Convention of the Japanese Psychological Association
Presentation: How can we measure children’s inner speech? Examining the objective measurement and developmental trajectory of inner speech using a mental counting task
Authors: Kota Otani, Ryoichi Watanabe, Ryuta Kuwamizu, Nozomi Yamamoto, Yusuke Moriguchi
Award: Excellent Presentation Award, 89th Annual Convention of the Japanese Psychological Association
