Porcelli Anthony J, Cruz Daniel, Wenberg Karen, Patterson Michael D, Biswal Bharat B, Rypma Bart
Rutgers University, United States.
Physiol Behav. 2008 Oct 20;95(3):282-9. doi: 10.1016/j.physbeh.2008.04.027. Epub 2008 May 20.
We examined the relationship between acute stress and prefrontal-cortex (PFC) based working memory (WM) systems using behavioral (Experiment 1) and functional magnetic resonance imaging (fMRI; Experiment 2) paradigms. Subjects performed a delayed-response item-recognition task, with alternating blocks of high and low WM demand trials. During scanning, participants performed this task under three stress conditions: cold stress (induced by cold-water hand-immersion), a room temperature water control (induced by tepid-water hand-immersion), and no-water control (no hand-immersion). Performance was affected by WM demand, but not stress. Cold stress elicited greater salivary cortisol readings in behavioral subjects, and greater PFC signal change in fMRI subjects, than control conditions. These results suggest that, under stress, increases in PFC activity may be necessary to mediate cognitive processes that maintain behavioral organization.
我们使用行为学范式（实验1）和功能磁共振成像（fMRI；实验2）来研究急性应激与基于前额叶皮质（PFC）的工作记忆（WM）系统之间的关系。受试者执行一项延迟反应项目识别任务，其中包含高WM需求试验和低WM需求试验交替的组块。在扫描过程中，参与者在三种应激条件下执行此任务：冷应激（通过冷水浸手诱导）、室温对照（通过温水浸手诱导）和无浸手对照（不浸手）。表现受WM需求影响，但不受应激影响。与对照条件相比，冷应激在行为学受试者中引发了更高的唾液皮质醇读数，在fMRI受试者中引发了更大的PFC信号变化。这些结果表明，在应激状态下，PFC活动的增加可能是介导维持行为组织的认知过程所必需的。
