Department of Psychiatry, University of Connecticut School of Medicine, Farmington, CT, USA.
Department of Psychology, Rochester Institute of Technology, Rochester, NY, USA.
Int J Obes (Lond). 2017 Oct;41(10):1489-1495. doi: 10.1038/ijo.2017.144. Epub 2017 Jun 20.
The present study investigated the value of intrasubject variability (ISV) as a metric for revealing differences in cognition and brain activation associated with an obese versus lean body mass.
Ninety-six adolescents with a lean body mass (body mass index (BMI) percentile=5-85), and 92 adolescents with an obese body mass (BMI percentile ⩾95), performed two tasks (Stroop and Go/No-Go) challenging response inhibition skills. The s.d. values and averages of their reaction time and P300 electroencephalographic responses to task stimuli were computed across trials.
During the Go/No-Go task, the reaction times of subjects with an obese body mass were more variable than those of their lean body mass peers. Accompanying the greater ISV in reaction times was a group difference in P300 amplitude ISV in the opposite direction across both tasks. The effect sizes associated with these group differences in ISV were marginally greater than the effect sizes for the comparisons of the group means.
ISV may be superior to the mean as a tool for differentiating groups without significant cognitive impairment. The co-occurrence of reduced ISV in P300 amplitude and elevated ISV in reaction time may indicate a constraint among obese adolescent girls in the range of information processing strategies and neural networks that can compete to optimize response output. It remains to be determined whether this decrement in neural plasticity has implications for their problem solving skills as well as their response to weight management interventions.
本研究旨在探讨个体内变异性（ISV）作为一种指标的价值，用于揭示与肥胖和瘦体重相关的认知和大脑激活差异。
96 名瘦体重青少年（体重指数（BMI）百分位=5-85）和 92 名肥胖青少年（BMI 百分位⩾95）进行了两项任务（Stroop 和 Go/No-Go），以挑战反应抑制技能。计算了他们在整个试验中对任务刺激的反应时间和 P300 脑电图反应的标准差值和平均值。
在 Go/No-Go 任务中，肥胖青少年的反应时间变异性大于瘦体重青少年。与反应时间更大的 ISV 相伴的是，在两个任务中，P300 振幅 ISV 的组间差异呈相反方向。这些 ISV 组间差异的效应大小略大于组间均值比较的效应大小。
ISV 可能优于均值，是一种区分无明显认知障碍的群体的工具。P300 振幅中 ISV 降低和反应时间中 ISV 升高的同时出现，可能表明肥胖青少年女孩在信息处理策略和神经网络的范围内存在竞争，以优化反应输出的约束。尚需确定这种神经可塑性的降低是否对她们的解决问题的技能以及对体重管理干预的反应有影响。
