Tohoku University Graduate School of Medicine, Japan.
Psychosom Med. 2011 Sep;73(7):588-97. doi: 10.1097/PSY.0b013e318223c7f8. Epub 2011 Aug 23.
Individuals with alexithymia have a reduced ability to use their feelings to guide their behavior appropriately in social situations. To reveal the capacity to use emotional signals in alexithymia under conditions of uncertainty, this study investigates neural substrates and performance on the Iowa Gambling Task (IGT), which was developed to assess decision making based on emotion-guided evaluation.
The participants were 10 men with alexithymia and 13 without. Alexithymia was assessed by the 20-item Toronto Alexithymia Scale. Regional cerebral blood flow (rCBF) was measured by [¹⁵O]-H₂O positron emission tomography during four trials of the IGT and two visuomotor control tasks.
The participants with alexithymia failed to learn an advantageous decision-making strategy, with performance differing significantly from the nonalexithymic group in the fourth IGT trial (p = .029). Comparing performance between the IGT and the control tasks, both groups showed brain activation in the dorsolateral frontal area, inferior frontal lobe, pre-supplementary motor area, inferior parietal lobe, fusiform gyrus, and cerebellum. Men with alexithymia showed lower rCBF in the medial frontal area (Brodmann area [BA] 10) and higher rCBF in the caudate and occipital areas in the first and second IGT trials, which are within a learning phase according to test performance data. All brain data were significant at p ≤ .001, uncorrected.
BA10 activity may be associated with using internal signals accompanying affective evaluation of the stimuli, which is crucial for successful decision making. Reduced BA10 activity in participants with alexithymia suggests that they may not use an emotion-based biasing signal to lead to advantageous decision making.
患有述情障碍的个体在社交情境中使用自身感受来适当引导行为的能力降低。为了揭示在不确定条件下述情障碍者使用情绪信号的能力，本研究采用了旨在评估基于情绪引导评估的决策制定的 Iowa 赌博任务（IGT），考察了神经基础和参与者的表现。
参与者为 10 名男性述情障碍者和 13 名非述情障碍者。采用 20 项多伦多述情障碍量表评估述情障碍。在 IGT 的 4 次试验和 2 次视动控制任务期间，通过[¹⁵O]-H₂O 正电子发射断层扫描测量局部脑血流（rCBF）。
述情障碍者未能学习到有利的决策策略，在 IGT 的第 4 次试验中的表现与非述情障碍组有显著差异（p =.029）。将 IGT 和控制任务的表现进行比较，两组在背外侧额区、额下回、补充运动区、下顶叶、梭状回和小脑均显示脑激活。述情障碍男性在 IGT 的第 1 次和第 2 次试验中，额内侧区（Brodmann 区[BA]10）的 rCBF 较低，尾状核和枕叶区的 rCBF 较高，而根据测试表现数据，这两个区域均处于学习阶段。所有脑数据均在 p ≤.001 未经校正的情况下具有统计学意义。
BA10 区的活动可能与使用伴随对刺激的情感评估的内部信号有关，这对成功决策至关重要。述情障碍者 BA10 区活动减少表明，他们可能不会使用基于情绪的偏向信号来做出有利的决策。
