Department of Psychology, Sapienza University of Rome, Rome, Italy.
IRCCS Istituto delle Scienze Neurologiche di Bologna, Bologna, Italy.
Transl Psychiatry. 2024 Oct 22;14(1):446. doi: 10.1038/s41398-024-03162-w.
The "Sign-tracker/Goal-tracker" (ST/GT) is an animal model of individual differences in learning and motivational processes attributable to distinctive conditioned responses to environmental cues. While GT rats value the reward-predictive cue as a mere predictor, ST rats attribute it with incentive salience, engaging in aberrant reward-seeking behaviors that mirror those of impulse control disorders. Given its potential clinical value, the present study aimed to map such model onto humans and investigated resting state functional magnetic resonance imaging correlates of individuals categorized as more disposed to sign-tracking or goal-tracking behavior. To do so, eye-tracking was used during a translationally informed Pavlovian paradigm to classify humans as STs (n = 36) GTs (n = 35) or as Intermediates (n = 33), depending on their eye-gaze towards the reward-predictive cue or the reward location. Using connectivity and network-based approach, measures of resting state functional connectivity and centrality (role of a node as a hub) replicated preclinical findings, suggesting a major involvement of subcortical areas in STs, and dominant cortical involvement in GTs. Overall, the study strengthens the translational value of the ST/GT model, with important implications for the early identification of vulnerable phenotypes for psychopathological conditions such as substance use disorder.
“标记追踪/目标追踪”(ST/GT)是一种动物模型,用于研究学习和动机过程中的个体差异,这些差异归因于对环境线索的独特条件反射。GT 大鼠将奖励预测线索仅仅视为一种预测器,而 ST 大鼠则赋予其激励显著性,从而表现出异常的奖励寻求行为,这些行为与冲动控制障碍的行为相似。鉴于其潜在的临床价值,本研究旨在将该模型映射到人类身上,并研究将个体归类为更倾向于标记追踪或目标追踪行为的静息状态功能磁共振成像相关性。为此,使用眼动追踪技术在转化启发式的巴甫洛夫范式期间对人类进行分类,根据他们的目光注视是朝向奖励预测线索还是奖励位置,将人类分为 ST 组(n=36)、GT 组(n=35)或中间组(n=33)。使用连接和基于网络的方法,静息状态功能连接和中心性(节点作为枢纽的作用)的测量复制了临床前发现,表明 ST 主要涉及皮质下区域,而 GT 主要涉及皮质区域。总体而言,该研究加强了 ST/GT 模型的转化价值,对早期识别物质使用障碍等精神病理学疾病的易感性表型具有重要意义。