Most international reports regarding research on autism spectrum disorder（ASD）and the characteristics of dreams have conducted analysis based on emotions and themes of dreams; however, there are few reports on this topic in Japan. Recently, DSM-5 added a new paresthesia to the diagnostic criteria for ASD; therefore, it is expected that future research on paresthesia and dream sensations will be needed. The purpose of this study is to classify the sensory and emotional features of dreams recorded in the home dream diaries of adolescents with ASD. Dream materials were obtained from a fourth-year college student with ASD the collaborator was able to recall their dreams in vivid detail and enjoyed the dream reports. Qualitative analysis suggested that the content of the recalled dream reflected the vividness of the visual and auditory image and hypersensitivity of the minor sensations in the dreams such as gustatory and olfactory. Additionally, the collaborator experienced many positive emotions in their recalled dreams, although few negative emotions surfaced. A future challenge is to investigate the relationship between paresthesia in ASD and dreams using an enough sample data spanning from childhood to adolescence.

This study attempted to develop a Representation Style Inventory（RSI）for measuring individual differences in the preference and experiences for object-visual, spatial-visual, and verbal thinking. On the basis of factor analysis, we obtained three factors in the questionnaire. A 10-item object-visual thinking scale assesses preferences and experiences for representing colorful, pictorial, and high-resolution images of individual objects or scenes; a 10-item spatial-visual thinking scale assesses preferences and experiences for representing schematic images and spatial locations of objects; and a 10-item verbal thinking scale assesses preferences and experiences for processing verbal information. Additionally, the RSI demonstrated acceptable internal reliability as well as construct and criterion-related validity. This study’s results showed that the RSI is useful for measuring preferences and experiences for object-visual, spatial-visual, and verbal thinking.

The origin of imagery ability is an important issue that has not yet been clarified. This paper attempts to discuss, from two perspectives, the possibility that individual differences in imagery ability have innate bases.

The first is an attempt to infer hypothetically the innate bases of imagery ability by referring to the findings from behavioral genetic studies for the characteristics of the imagery test scores’distribution, personality factors that relate to individual differences in imagery ability, and the mechanisms on which imagery ability is based.

The second is an attempt in children to confirm individual imagery differences similar to adults and to infer the innate bases of imagery ability based on the findings in children that verify the predictive efficacy of imagery tests on cognitive tasks and events, and findings regarding how children respond to imagery tests. In this paper,imagery ability dimensions, that is, vividness, controllability, preference（imagery type）, and absorption, are considered. Based on the findings from behavioral genetic studies, it can be inferred that imagery ability has innate bases in the following points:（a）Positive skews in the score distributions of vividness, controllability and visualization may indicate the universality of image generation.（b）Personality factors that relate to imagery traits have innate bases: temperaments（combination of neuroticism and version, and persistence）,aesthetic sensitivity, repressive tendency/ego permissiveness for vividness, neuroticism for controllability,openness and self-transcendence for absorption, and also neuroticism for fantasy proneness.（c）Mechanisms on which imagery ability is based have innate bases: large capacity of visual working memory for vividness and preference, neuropsychological bases for vividness and imagery type, executive functions of working memory for controllability, encodings that correspond to imagery type for preference, and strong imaginative involvement and induction of relaxation for absorption. Based on the findings from developmental studies in children, it can be confirmed that individual imagery differences similar to adults have already become actualized in schoolchildren,which suggests the involvement of innate factors in a similar way to adults:（a）For all imagery ability dimensions, imagery tests have predictive efficacy for cognitive tasks and events in children, which contributes equally to adults in identifying mechanisms of imagery ability.（b）Children's responses to imagery tests are very similar to those of adults, especially with the following basic characteristics in common: the cross-modality characteristic of vividness, the loose associations between each of the dimensions, the positive skews in the score distributions of vividness, controllability and visualization, and the normality of the absorption scores. The very expectation that behavioral genetic studies will be conducted on each dimension of imagery ability, and the need for research into individual imagery differences in young children and longitudinal studies are offered.