Biomedical subjects

Atsunobu Suzuki

Publications and source records attributed to Atsunobu Suzuki.

6 recordsLinked to original sources

PubMed2006

Decline or improvement? Age-related differences in facial expression recognition.

We examined age-related differences in facial expression recognition in association with potentially interfering variables such as general cognitive ability (verbal and visuospatial abilities), face recognition ability, and the experiences of positive and negative emotions. Participants comprised 34 older (aged 62-81 years) and 34 younger (aged 18-25 years) healthy Japanese adults. The results showed not only age-related decline in sadness recognition but also age-related improvement in disgust recognition. Among other variables, visuospatial ability was moderately related to facial expression recognition in general, and the experience of negative emotions was related to sadness recognition. Consequently, age-related decline in sadness recognition was statistically explained by age-related decrease in the experience of negative emotions. On the other hand, age-related improvement in disgust recognition was not explained by the interfering variables, and it reflected a higher tendency in the younger participants to mistake disgust for anger. Possible mechanisms are discussed in terms of neurobiological and socio-environmental factors.

Adolescent↗

PubMed2006

Disgust-specific impairment of facial expression recognition in Parkinson's disease.

There is contradictory evidence regarding whether the impairments of the recognition of emotional facial expressions in Parkinson's disease are specific to certain emotions such as disgust and fear. Generally, neurological case reports on emotion-specific impairments have been suspected of being confounded with the factor of task difficulty. Using a refined assessment method in which the difficulty factors were controlled by means of mixed facial expressions and item response theory, we attempted to clarify whether Parkinson's disease disproportionately impaired the recognition of specific emotions. We studied 14 patients with Parkinson's disease and 39 healthy controls who were matched in terms of gender, age, years of education and intelligence quotient. Whereas the refined method revealed that the patients with Parkinson's disease displayed significantly lower scores in disgust recognition alone, conventional methods failed to detect this impairment. In addition, control measures including face recognition abilities did not statistically explain the impairment observed in the patients. The results indicate that Parkinson's disease can indeed selectively impair the recognition of facial expressions of disgust; this provides concrete evidence for emotion-specific impairments that sufficiently withstands criticisms regarding the difficulty artefacts. Furthermore, the results support the proposed role of the basal ganglia-insula system in disgust recognition. This study effectively demonstrates the benefits of refining neuropsychological assessment by taking advantage of the modern psychometric theory.

Aged↗

PubMed2006

Is the genetic structure of human personality universal? A cross-cultural twin study from North America, Europe, and Asia.

This study examined whether universality of the 5-factor model (FFM) of personality operationalized by the Revised NEO Personality Inventory is due to genetic influences that are invariant across diverse nations. Factor analyses were conducted on matrices of phenotypic, genetic, and environmental correlations estimated in a sample of 1,209 monozygotic and 701 dizygotic twin pairs from Canada, Germany, and Japan. Five genetic and environmental factors were extracted for each sample. High congruence coefficients were observed when phenotypic, genetic, and environmental factors were compared in each sample as well as when each factor was compared across samples. These results suggest that the FFM has a solid biological basis and may represent a common heritage of the human species.

Canada↗

PubMed2005

Measuring individual differences in sensitivities to basic emotions in faces.

The assessment of individual differences in facial expression recognition is normally required to address two major issues: (1) high agreement level (ceiling effect) and (2) differential difficulty levels across emotions. We propose a new assessment method designed to quantify individual differences in the recognition of the six basic emotions, 'sensitivities to basic emotions in faces.' We attempted to address the two major assessment issues by using morphing techniques and item response theory (IRT). We used morphing to create intermediate, mixed facial expression stimuli with various levels of recognition difficulty. Applying IRT enabled us to estimate the individual latent trait levels underlying the recognition of respective emotions (sensitivity scores), unbiased by stimulus properties that constitute difficulty. In a series of two experiments we demonstrated that the sensitivity scores successfully addressed the two major assessment issues and their concomitant individual variability. Intriguingly, correlational analyses of the sensitivity scores to different emotions produced orthogonality between happy and non-happy emotion recognition. To our knowledge, this is the first report of the independence of happiness recognition, unaffected by stimulus difficulty.

Adolescent↗

PubMed2004

Genetic and environmental structure of Cloninger's temperament and character dimensions.

The multivariate genetic and environmental structure of Cloninger's Temperament and Character Inventory (TCI) was investigated in a sample of 617 pairs of adolescent and young adult twins from Japan. Additive genetic factors accounted for 22% to 49% of the variability on all TCI temperament scales. Although the theory predicts lower heritability for the character scales, all character subscales had a substantial genetic contribution, and nonshared environmental influences accounted for the remainder. Multivariate genetic analyses showed that several subscales used to define one dimension shared a common genetic basis with subscales defining others. Using the degree of shared genetic influence as the basis to rearrange the TCI subscales into new dimensions, it was possible to create genetically independent scales. The implications for personality measurement, theory, and molecular genetic research are discussed.

Adolescent↗

PubMed2003

Application of the somatic marker hypothesis to individual differences in decision making.

The somatic marker hypothesis (Damasio, Tranel, & Damasio, 1991) is a controversial theory asserting that somatic activities implicitly bias human behavior. In this study, we examined the relationship between choice behaviors in the Iowa Gambling Task and patterns of skin conductance responses (SCRs) within a healthy population. Results showed that low SCRs for appraising the monetary outcome of risky decisions were related to persistence in risky choices. Such adherence to risky decisions was not related to poor explicit knowledge about the task. On the other hand, anticipatory SCRs and the effect of them on performance were not confirmed. Our findings suggest that a variation in covert physiological appraisal underlies individual differences in decision making.

Adolescent↗