Response Inhibition In Children With High Functioning Autism: A Near-infrared Spectroscopy Study

【Objective】The objectives of this study were to compare the function of response inhibition between children with high functioning autism (HFA) and normal controls; to investigate the characteristics of blood flow activity changing in prefrontal cortex during response inhibition task; to investigate the relationship between response inhibition and clinical symptoms and to explore the neurophysiology basis of pathogenesis in children with HFA.【Methods】Go/no-go task and Stroop task were applied to assess the function of response inhibition in 26 children with HFA and 20 normal controls, while all the data of oxygenated hemoglobin (oxy-Hb) concentration levels in prefrontal cortex area were collected by functional near-infrared spectroscopy (NIRS), which would be in a statistical comparison between HFA group and healthy controls by multivariate analysis of variance (MANOVA). And correlation between scores of Childhood Autism Rating Scale (CARS) and behavioral performance of response inhibition or oxy-Hb concentration levels in prefrontal cortex area of children with HFA were analyzed,too.【Results】(1) The HFA group had more commission errors [(6.19±5.24) vs (2.90±1.59), P<0.05] and longer reaction time [(577.10±123.85) ms vs (476.60±46.39) ms, P<0.05] than control group during no-go task, after controlling for IQ or age, the two groups still had significant difference in reaction time (P<0.05); but the two groups had no difference in commission errors and reaction time during stroop task (P>0.05). (2) There was a positive correlation between scores of CARS and commission errors(r=0.403, P=0.041) or reaction time(r=0.427, P=0.029) in HFA group during no-go task (P < 0.05), but no correlation during stroop task (P>0.05). (3) The HFA group had lower levels of oxy-Hb concentration in the right prefrontal cortex area during performing no-go task than that in controls [(-0.35±0.47)(10^-2×a.u) vs (0.16±0.67)(10^-2×a.u)], but higher levels in the left prefrontal cortex than that in controls[(0.60±0.74)(10^-2×a.u) vs (0.02±0.70)(10^-2×a.u)], after controlling for IQ or age, the two groups still had significant difference in reaction time (P<0.05); but the two groups had no difference in concentration levels of oxy-Hb during stroop task (P>0.05). (4)There was a negative correlation between CARS score and concentration levels of oxy-Hb (r=-0.423, P=0.032) in the right prefrontal cortex area in HFA group during performing no-go task (P<0.05), but no correlation during stroop color-word interference task (P>0.05).【Conclusion】(1) The children with HFA have deficits in some but not all aspects of response inhibition. (2) There may be a positive correlation between lesion degree of response inhibition and severity of clinical symptom in children with HFA. (3) It was shown that levels of oxy-Hb concentration in right prefrontal cortex were significantly negatively correlated with the severity of clinical symptoms in children with HFA.