Parcet Maria Antònia, Adrián-Ventura Jesús, Costumero Víctor, Ávila César
Neuropsychology and Functional Neuroimaging, Jaume I University, Castellón, Spain.
Center for Brain and Cognition, Pompeu Fabra University, Barcelona, Spain.
Front Behav Neurosci. 2020 Apr 9;14:53. doi: 10.3389/fnbeh.2020.00053. eCollection 2020.
Sensitivity to reward is a personality trait that predisposes a person to several addictive behaviors, including the presence of different risky behaviors that facilitates uncontrolled eating. However, the multifactorial nature of obesity blurs a direct relationship between the two factors. Here, we studied the brain anatomic correlates of the interaction between reward sensitivity and body mass index (BMI) to investigate whether the coexistence of high BMI and high reward sensitivity structurally alters brain areas specifically involved in the regulation of eating behavior. To achieve this aim, we acquired T1-weighted images and measured reward sensitivity using the Sensitivity to Punishment and Sensitivity to Reward Questionnaire (SPSRQ) and BMI in a sample of 206 adults. Results showed that reward sensitivity and BMI were not significantly correlated. However, neuroimaging results confirmed a relationship between BMI and reduced volume in the medial and lateral orbitofrontal cortex, and between reward sensitivity and lower striatum volume. Importantly, the interaction between the two factors was significantly related to the right anterior hippocampus volume, showing that stronger reward sensitivity plus a higher BMI were associated with reduced hippocampal volume. The hippocampus is a brain structure involved in the higher-order regulation of feeding behavior. Thus, a dysfunctional hippocampus may contribute to maintaining a vicious cycle that predisposes people to obesity.
对奖励的敏感是一种人格特质，它使一个人易产生多种成瘾行为，包括存在不同的危险行为，这些行为会助长无节制饮食。然而，肥胖的多因素性质模糊了这两个因素之间的直接关系。在此，我们研究了奖励敏感性与体重指数（BMI）之间相互作用的脑解剖学关联，以调查高BMI与高奖励敏感性并存是否会在结构上改变专门参与饮食行为调节的脑区。为实现这一目标，我们获取了T1加权图像，并在206名成年人的样本中使用惩罚敏感性和奖励敏感性问卷（SPSRQ）测量奖励敏感性以及测量BMI。结果显示，奖励敏感性与BMI无显著相关性。然而，神经影像学结果证实了BMI与内侧和外侧眶额皮质体积减小之间的关系，以及奖励敏感性与纹状体体积减小之间的关系。重要的是，这两个因素之间的相互作用与右侧前海马体体积显著相关，表明更强的奖励敏感性加上更高的BMI与海马体体积减小有关。海马体是参与进食行为高级调节的脑结构。因此，功能失调的海马体可能有助于维持一个使人易患肥胖症的恶性循环。
