The current study was conducted to review the literature related to cognitive psychological studies for individuals with intellectual disabilities (IDs) to reveal their characteristics and issues for future research. A summary of 206 publications produced through August 2023 suggests four characteristics of these studies in Japan. First, the number of publications in this area in Japan has been declining. Second, while many cross-sectional studies have been reported, longitudinal studies remain scarce. Third, few studies have examined individuals with IDs, classified by causative or comorbidity, excluding Down syndrome and autism. Fourth, considerable research has examined the original conditions, with tasks from earlier studies under the original framework, employing analyses with multiple indicators. It is noteworthy that many of these original tasks were influenced by Soviet psychology.

This article presents a comprehensive review of the literature on the cognitive psychology of executive functions in individuals with intellectual disabilities (IDs) in Japan. Specifically, it highlights research by Japanese scholars, in line with the theme of the special issue titled “Special Education in Japan.” The paper begins by defining the concept and components of executive functions. Subsequently, it contextualizes executive functions within the realm of intellectual disability research, considering both the limitations of intellectual functioning and adaptive behavior, which serve as diagnostic criteria for IDs. An overview of Japanese research on executive functions in this population is also provided, addressing essential questions, such as the nature of impairments in executive functions, their relationship with adaptive behavior and academic skills, and potential intervention strategies. In conclusion, this research outlines future research directions to promote self-reliance and social participation among individuals with IDs.

Memory is a widely investigated cognitive domain in individuals with intellectual disabilities (IDs). While experimental studies of memory in IDs have been vigorously conducted in Japan, much of the research has been published in Japanese, potentially limiting its international visibility. This research seeks to provide a concise review of studies on memory in individuals with IDs as presented in Japanese publications. Examining the two research topics of short-term memory and control processes in memory, this review elucidates the contributions of earlier Japanese studies of memory in individuals with IDs and the significance of further research in this field.

This concise review introduces Japanese research exploring the role of language-based regulation in perception and action among individuals with intellectual disabilities. Earlier findings have validated that even in movements traditionally regarded as reflexive and automatic, such as optokinetic nystagmus and body swaying, individuals with intellectual disabilities who struggle with language-based action regulation might encounter difficulties in smooth and stable execution. The effectiveness of visual cues was also reported for movement by individuals with intellectual disabilities. The significance of assessing individuals with intellectual disabilities was emphasized by assessing their language-based action-regulation abilities alongside their other psychological abilities. Furthermore, the necessity for a more precise categorization of distinct intellectual disabilities was highlighted. The emphasis on perception and action in Japanese empirical psychology for individuals with intellectual disabilities aligns with current concepts in cognitive psychology such as affordances and embodied cognition.

We conducted a questionnaire survey with 36 elementary school teachers who work with 93 foreign students to investigate the hurdles teachers face in supporting foreign students and the difficulties these students encounter in participating in classes and school life. Analyses employing the Mann–Whitney U test, the Pearson’s chi-square test and multiple regression analysis demonstrated that all elementary school teachers had trouble communicating with students’ parents from foreign backgrounds. Additionally, this research validated that according to the teachers, learning factors such as “listening,” “writing,” and “calculation and reasoning ability” substantially impacted foreign students’ participation in classes and school life. This work may contribute to elevating approaches for supporting foreign students as they navigate their struggles and serve as a foundation for more in-depth research on this topic.

It is proposed that in Japanese, the transition from the core vowels of the first syllables of words to the subsequent segments affects the occurrence of stuttering. This study aimed to investigate whether this segmental transition affects the frequency of stuttering with not only simple words but also with compound words. Participants were 14 school-age children who stuttered. Reading tasks of 16 simple and 16 compound words were used. The results showed that the frequency of stuttering on words with an inter-syllabic transition was significantly higher than on those with an intra-syllabic transition for both simple and compound words. These results suggest that the transition from core vowels in the first syllables of words affects the occurrence of stuttering not only in simple word production, but in compound word production as well. In addition, the frequency of stuttering with each type of transition was not significantly different between simple and compound words. These results suggest that the morphological factor that combines words would not significantly affect the occurrence of stuttering in school-age children.

This research examined the effects of the family-centered positive behavior support (PBS) approach and parent monitoring on the behaviors of young children with autism spectrum disorders (ASDs) and their parents. The family-centered PBS approach involved collaboratively selecting target behaviors and routines, parental monitoring of children’s target behaviors, planning behavior intervention strategies for each routine based on ABC analysis results, coaching parents on the strategies, and providing feedback on the outcomes of the parents’ implementation of the strategies. The results confirmed that the family-centered PBS approach was associated with enhancements in the children’s target behaviors. Additionally, the findings validated that the parents may apply the behavior intervention strategies to nontrained routines. Possible factors that influenced this outcome were that the parent monitoring may have functioned as a self-monitoring of the parents’ behaviors that the checklist in the parent monitoring may have served as a discriminative stimulus for the implementation of the intervention plan, that feedback promoted parents’ attention to the situation where the target behaviors occurred, and that the parents were relatively positive about their parenting.