Department of Psychological Clinical Science, University of Toronto, Toronto, Ontario, Canada.
Department of Psychology (Scarborough), University of Toronto, Toronto, Ontario, Canada.
Cereb Cortex. 2021 Mar 31;31(5):2701-2719. doi: 10.1093/cercor/bhaa384.
The rodent ventral and primate anterior hippocampus have been implicated in approach-avoidance (AA) conflict processing. It is unclear, however, whether this structure contributes to AA conflict detection and/or resolution, and if its involvement extends to conditions of AA conflict devoid of spatial/contextual information. To investigate this, neurologically healthy human participants first learned to approach or avoid single novel visual objects with the goal of maximizing earned points. Approaching led to point gain and loss for positive and negative objects, respectively, whereas avoidance had no impact on score. Pairs of these objects, each possessing nonconflicting (positive-positive/negative-negative) or conflicting (positive-negative) valences, were then presented during functional magnetic resonance imaging. Participants either made an AA decision to score points (Decision task), indicated whether the objects had identical or differing valences (Memory task), or followed a visual instruction to approach or avoid (Action task). Converging multivariate and univariate results revealed that within the medial temporal lobe, perirhinal cortex, rather than the anterior hippocampus, was predominantly associated with object-based AA conflict resolution. We suggest the anterior hippocampus may not contribute equally to all learned AA conflict scenarios and that stimulus information type may be a critical and overlooked determinant of the neural mechanisms underlying AA conflict behavior.
啮齿动物的腹侧和灵长类动物的前海马体被认为与趋近-回避（AA）冲突处理有关。然而，尚不清楚该结构是否有助于 AA 冲突的检测和/或解决，以及它的参与是否扩展到没有空间/上下文信息的 AA 冲突条件。为了研究这一点，神经健康的人类参与者首先学习接近或回避单个新的视觉对象，以最大限度地获得积分。接近会导致正、负对象分别获得积分增益和损失，而回避对得分没有影响。然后在功能磁共振成像期间呈现这些物体的成对，每个物体具有非冲突（正-正/负-负）或冲突（正-负）的效价。参与者要么做出 AA 决策以得分（决策任务），要么指示物体是否具有相同或不同的效价（记忆任务），要么遵循视觉指令来接近或回避（动作任务）。多元和单变量的融合结果表明，在中颞叶中，眶额皮层而不是前海马体，与基于物体的 AA 冲突解决关系最密切。我们认为，前海马体可能不会平等地参与所有习得的 AA 冲突情景，并且刺激信息类型可能是 AA 冲突行为背后的神经机制的关键且被忽视的决定因素。
