Biomedical subjects

Kiyoshi Yaguchi

Publications and source records attributed to Kiyoshi Yaguchi.

3 recordsLinked to original sources

PubMed2005

Deviant gaze processing in children with autism: an ERP study.

This study investigated event-related potentials (ERP) during an oddball task in which detection of specific eye direction was required of children with and without autism. The detection of a change in eye direction elicited occipito-temporal negativity, which had two major differences between children with and without autism. First, while this occipito-temporal negativity predominated in the right hemisphere of typically developed children, it was distributed equally bilaterally in children with autism. Second, the amplitude of this negativity was more pronounced in typically developed children in response to the detection of direct gaze as compared to averted gaze, but was not sensitive to direct/averted gaze direction in children with autism, which converges with behavioral reports. The results concur with previous literature, suggesting the importance of the right hemisphere, especially the superior temporal sulcus, in gaze processing. Results indicate that deviant neural substrates might be involved in gaze processing in individuals with autism.

Adolescent↗

PubMed2003

Eye contact does not facilitate detection in children with autism.

Eye contact is crucial in achieving social communication. Deviant patterns of eye contact behavior are found in individuals with autism, who suffer from severe social and communicative deficits. This study used a visual oddball paradigm to investigate whether children with high functioning autism have difficulty in detecting mutual gaze under experimental conditions. The results revealed that children with autism were no better at detecting direct gaze than at detecting averted gaze, which is unlike normal children. This suggests that whereas typically developing children have the ability to detect direct gaze, children with autism do not. This might result in altered eye-contact behavior, which hampers subsequent development of social and communicative skills.

Adolescent↗

PubMed2002

Sound complexity and 'speechness' effects on pre-attentive auditory discrimination in children.

The evidence in adults suggests that at a cortical level simple and complex sounds are processed by partly divergent subsystems. In children, central processing of sounds differing in complexity has not been investigated. Therefore, the present study examined preconscious discrimination of the differences in sound frequency and duration as a function of sound complexity in 8-10-year-old children. A mismatch negativity (MMN) component of auditory event-related potentials was elicited in a paradigm where 'deviant' (rare) stimuli were either shorter in duration or higher in frequency than the 'standard' (repetitive) sounds. Vowels and vowel-matched complex and simple tones were presented in separate sequences. The stimulus complexity effects were sizable and appeared as larger areas and shorter and more consistent latencies of the MMNs, elicited by more complex stimuli. In addition, the vowel frequency MMN showed left hemisphere preponderance compared to the complex tone frequency MMN. No such effect was found for the duration decrement MMNs. In addition, the complex tone duration decrement MMN was distributed posteriorly to either the vowel or sinusoidal tone MMNs. A late discriminative negativity, LDN, did not show consistent effects of sound complexity. In conclusion, acoustically rich sound content facilitates auditory sensory discrimination in 8-10-year-old children. The sound 'speechness' effects were not as robust though present. Unlike adults, children demonstrated high intersubject variability in discriminating spectrally poor, but not rich, sounds. The discrimination of the sound duration appears to differ from that of the sound frequency in nature and, consequently, in the neural substrates.

Acoustic Stimulation↗