Subjective health awareness and sensory ability of taste and olfaction: A case study of a health promotion class for older people.

The quality of the dietary habits of older adults is important for increasing healthy life expectancy. As with other physical senses, the senses of taste and olfaction change with age. In contrast to physical sensations that can be visibly compared with those of other people, taste and olfaction are personal sensations, making it challenging to infer associated changes. This study investigated the characteristics of taste and olfaction in healthy older adults and compared them with those of young adults. In the taste assessment, threshold values were measured using the whole-mouth method with a diagnostic assay kit (Tastedisc). The olfactory assessment measured the overall identification ability using a card-type olfactory identification test kit (Open Essence). Additionally, participants' subjective health awareness was measured using a visual analog scale. The taste and olfactory assessments results showed that the older group had lower overall sensory sensitivity than the young group, and that there was no correlation between taste and olfactory sensitivity in the older group, while a trend was observed in the young group. Moreover, there was no significant difference between the two groups regarding subjective health awareness, indicating that participants in our research considered themselves healthy regardless of age. This suggests that the subjective health awareness of older people in the health promotion class is somehow independent from their sensory ability.

First bite for hardness judgment as haptic exploratory procedure.

This study examines whether the modulation of biting behavior while subjects are engaged in food texture judgment can be explained as an intra-oral exploratory procedure optimized for recognizing a specified sensory attribute. Subjects were asked to compare two cheese samples for "the force required to penetrate the sample with the molar teeth" (the definition for "hardness" used in this study). Based on this definition, we hypothesize that the subjects targeted the first peak of the bite time-force profile (i.e. the intra-oral phenomenon of the initial fracture) as an essential property for judgment. We observed significant elongation of the first peak in the judgmental biting, compared to the biting without judgment, for all subjects. Shortening of the second peak (teeth-to-teeth contact) duration and decrease of the second peak force were also observed for all subjects. These active biting modulations suggested that the first peak was targeted for judgment, whereas the second peak was not targeted. The sample with greater maximum force or time-integral of the bite force at the first peak was also judged as requiring greater force; these agreements were statistically significant. This result confirmed that the parameters related to the first peak were targeted as judgmental cues. We concluded that the biting behavior in hardness judgment functions as the exploratory procedure and was optimized for encoding the target sensory properties.

Gazefinder as a clinical supplementary tool for discriminating between autism spectrum disorder and typical development in male adolescents and adults.

BACKGROUND: Gaze abnormality is a diagnostic criterion for autism spectrum disorder (ASD). However, few easy-to-use clinical tools exist to evaluate the unique eye-gaze patterns of ASD. Recently, we developed Gazefinder, an all-in-one eye-tracking system for early detection of ASD in toddlers. Because abnormal gaze patterns have been documented in various ASD age groups, we predicted that Gazefinder might also detect gaze abnormality in adolescents and adults. In this study, we tested whether Gazefinder could identify unique gaze patterns in adolescents and adults with ASD. METHODS: We measured the percentage of eye fixation time allocated to particular objects depicted in movies (i.e., eyes and mouth in human face movies, upright and inverted biological motion in movies that presented these stimuli simultaneously, and people and geometry in movies that presented these stimuli simultaneously) by male adolescents and adults with ASD (N = 26) and age-matched males with typical development (TD; N = 35). We compared these percentages between the two groups (ASD and TD) and with scores on the social responsiveness scale (SRS). Further, we conducted discriminant analyses to determine if fixation times allocated to particular objects could be used to discriminate between individuals with and without ASD. RESULTS: Compared with the TD group, the ASD group showed significantly less fixation time at locations of salient social information (i.e., eyes in the movie of human faces without lip movement and people in the movie of people and geometry), while there were no significant groupwise differences in the responses to movies of human faces with lip movement or biological motion. In a within-group correlation analysis, a few of the fixation-time items correlated with SRS, although most of them did not. No items significantly correlated with SRS in both ASD and TD groups. The percentage fixation times to eyes and people, which exhibited large effect sizes for the group difference, could differentiate ASD and TD with a sensitivity of 81.0% and a specificity of 80.0%. CONCLUSIONS: These findings suggest that Gazefinder is potentially a valuable and easy-to-use tool for objectively measuring unique gaze patterns and discriminating between ASD and TD in male adolescents and adults.