Zomet Ativ, Amiaz Revital, Grunhaus Leon, Polat Uri
Goldschleger Eye Research Institute, Tel-Aviv University, Tel Hashomer, Israel.
Department of Psychiatry, Sheba Medical Center, Tel Hashomer, Israel.
Biol Psychiatry. 2008 Oct 15;64(8):667-671. doi: 10.1016/j.biopsych.2008.05.030. Epub 2008 Jul 17.
Major depression disorder is a syndrome that involves impairment of cognitive functions such as memory, attention, and plasticity. In this study, we explored whether depression affects perception as well.
We used a recently developed paradigm that assesses the filling-in process by probing false-positive reports (false alarm [FA]), hit rates (pHit), sensitivity (d'), and decision criteria (Cr). We used a Yes-No paradigm in a low-level detection task involving a Gabor target, in the presence of collinear flankers, inducing filling-in, with differing target-flanker separations of 3-15 lambda(wavelength). The depressive state of patients was assessed using the Hamilton Depression Rating Scale. Two groups were tested: an experimental group with major depression (n = 27) and a control group (n = 32).
The performances of the control and the experimental groups were not significantly different regarding d'. In contrast, a specific pattern of significant differences between the control group and the hospitalized group was found for the decision criterion, pHit, and pFA, but only for target-flanker separations of 3 lambda, whereas the results for the other separations were insignificant. The differences between the control and the depressed groups are not due to a global cognitive dysfunction in depression.
The results suggest that the filling-in process is deficient, probably because of reduced excitation among neurons. Neural excitation is a key factor in the neural processing involved in memory and decision making. In addition, it is still possible that the patients may be unable to match their internal representation to the changing sensory information.
重度抑郁症是一种涉及记忆、注意力和可塑性等认知功能受损的综合征。在本研究中，我们探讨了抑郁症是否也会影响感知。
我们使用了一种最近开发的范式，通过探测假阳性报告（误报[FA]）、命中率（pHit）、敏感性（d'）和决策标准（Cr）来评估填补过程。我们在一个涉及加博尔目标的低水平检测任务中使用了是/否范式，在共线侧翼刺激存在的情况下，诱导填补，目标 - 侧翼刺激的间距为3 - 15个波长（λ）。使用汉密尔顿抑郁量表评估患者的抑郁状态。测试了两组：重度抑郁症实验组（n = 27）和对照组（n = 32）。
对照组和实验组在d'方面的表现没有显著差异。相比之下，在决策标准、pHit和pFA方面，发现对照组和住院组之间存在显著差异的特定模式，但仅在目标 - 侧翼刺激间距为3λ时出现，而其他间距的结果不显著。对照组和抑郁症组之间的差异并非由于抑郁症中的整体认知功能障碍。
结果表明填补过程存在缺陷，可能是由于神经元之间的兴奋减少。神经兴奋是参与记忆和决策的神经处理中的关键因素。此外，患者仍有可能无法将其内部表征与不断变化的感觉信息相匹配。
