Schneider F, Gur R E, Alavi A, Seligman M E, Mozley L H, Smith R J, Mozley P D, Gur R C
Department of Psychiatry, School of Medicine, University of Pennsylvania, Philadelphia, USA.
Am J Psychiatry. 1996 Feb;153(2):206-12. doi: 10.1176/ajp.153.2.206.
The study addressed the question of whether unsolvable as opposed to solvable cognitive problems activate discrete neuronal systems in the human brain.
Twelve healthy humans tried to solve unsolvable anagrams. Solvable anagrams and a resting baseline after each anagram task served as control conditions in a within-subject design. Activation was measured with the equilibrium infusion method by using 15O-labeled water and positron emission tomography, with absolute quantitation of anatomically defined regional cerebral blood flow (CBF).
Compared to rest, both anagram tasks increased activity in frontal and temporal regions. The soluble task condition increased hippocampal activation and decreased mammillary bodies activity, while unsolvable anagrams were associated with increased CBF to the mamillary bodies and amygdala and decreased hippocampal activity.
A limbic network integrating negative emotion and cognition seems reflected in reciprocal diencephalic and limbic activation with solvable and unsolvable anagrams. Since unsolvable anagrams have been used to induce learned helplessness in humans, this finding may provide an initial step toward clarifying its neural substrate.
本研究探讨了与可解决的认知问题相比，不可解决的认知问题是否会激活人脑中不同的神经元系统这一问题。
12名健康受试者尝试解决无法解出的变位词。在受试者内设计中，可解决的变位词以及每个变位词任务后的静息基线作为对照条件。使用15O标记水和正电子发射断层扫描，通过平衡灌注法测量激活情况，并对解剖学定义的局部脑血流量（CBF）进行绝对定量。
与静息状态相比，两种变位词任务均增加了额叶和颞叶区域的活动。可解决任务条件增加了海马体的激活并降低了乳头体的活动，而无法解出的变位词则与乳头体和杏仁核的CBF增加以及海马体活动降低相关。
一个整合负面情绪和认知的边缘系统网络似乎反映在可解决和不可解决变位词时间脑和边缘系统的相互激活中。由于不可解决的变位词已被用于在人类中诱导习得性无助，这一发现可能为阐明其神经基础迈出了第一步。
