We report a method for quantitative analysis of erythema and pigmentation using a videomicroscope interfaced with a computer. The analysis was carried out by examining the brightness intensity of every picture element, composed of an image picked up from each band of red, green, and blue, and by deriving the quasi-absorbance value (absorbance index) from the mean brightness for each band. In assessments of UV-induced erythema and tanning, excellent linear correlations were found between the results obtained with our system and those with a narrow-band reflectance spectrometer. Moreover, the absorbance indices of haemoglobin and melanin solutions showed linear relationships with their concentrations in in vitro examination. As the monitored picture becomes out of focus if incorrect pressure is exerted on the skin, and as regions of interest can be chosen from a magnified image, this system offers excellent interobserver reproducibility, and is suitable for the evaluation of erythema or pigmented lesions which are too small or irregular to quantify by conventional methods such as colorimetry.

Aim:The aim of this study is to examine the hemodynamic changes induced by the cognitive process of facial expression by using multi-channel nearinfrared spectroscopy in healthy subjects with varying degrees of autism tendency.Methods: Subjects were 38 volunteers, 20 men and 18 women. Autism tendency was measured by the Autism Spectrum Quotient. The hemodynamic changes in the prefrontal cortex were measured by 24-channel near-infrared spectroscopy system, while subjects were asked to judge their own emotional response to standardized pictures of eight kinds of facial expressions on a computer screen.Results: There were significant negative correlations between Autism Spectrum Quotient scores and accuracy of fearful expression recognition as well as increases in the concentration of oxygenated hemoglobin in response to four kinds of emotional faces (fear, contempt, sadness and disgust). Conclusion:Our findings suggest that the greater tendency to autism that subjects have, the more difficulty they have in recognizing a fearful expression and the less hemodynamic change in the prefrontal cortex they show in response to negative facial expressions.

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: The purpose of the present study was to investigate the activity of frontal lobe of patients with schizophrenia during performance of two Japanese versions of the Stroop task (kana and kanji) by measuring changes in the concentration of oxygenated hemoglobin (oxyHb) with near-infrared spectroscopy (NIRS). Fourteen schizophrenia patients and 14 age-and gender-matched healthy control subjects participated in the study after giving consent. The relative changes of concentrations of oxyHb were measured by NIRS during performance of the Stroop task. Significant Stroop effects, as measured by the number of correct responses, were observed with both the kana and the kanji versions. Analysis of NIRS data revealed that the schizophrenia patients showed reduced activation in the prefrontal cortex compared to healthy controls during performance of the kana Stroop task, and that both schizophrenia patients and healthy controls showed lack of activity in the prefrontal cortex during performance of the kanji Stroop task. The results of the present study suggest the possibility that the kana Stroop task cause a greater Stroop effect than the kanji Stroop task, and schizophrenia patients show decreased prefrontal vascular reactivity associated with the inhibition required during the performance of the kana Stroop task. J. Med. Invest. 59 : 45-52, February, 2012

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