Neuroscience, Systems and Cognition (NEUROCS) Research Unit, Institute of Psychology, Catholic University of Louvain, Louvain-la-Neuve, Belgium.
PLoS One. 2011;6(8):e23190. doi: 10.1371/journal.pone.0023190. Epub 2011 Aug 12.
Olfactory abilities are now a flourishing field in psychiatry research. As the orbitofrontal cortex appears to be simultaneously implicated in odour processing and executive impairments, it has been proposed that olfaction could constitute a cognitive marker of psychiatric states. While this assumption appears promising, very few studies have been conducted on this topic among psychopathological populations. The present study thus aimed at exploring the links between olfaction and executive functions. These links were evaluated using two tasks of comparable difficulty, one known to rely on orbitofrontal cortex processing (i.e., a confabulation task), and one not associated with this area (i.e., Stop-Signal task).
METHODOLOGY/PRINCIPAL FINDINGS: Twenty recently detoxified alcoholic individuals and twenty paired controls took part in an experiment evaluating olfactory abilities and executive functioning (i.e., Stop-Signal task and confabulation task). Comorbidities and potential biasing variables were also controlled for. Alcoholic individuals exhibited impaired performance for high-level olfactory processing and significant confabulation problems as compared to controls (but no deficit in Stop-Signal task), even when the influence of comorbidities was taken into account. Most importantly, olfactory abilities and confabulation rates were significantly correlated in both groups.
CONCLUSIONS/SIGNIFICANCE: Alcoholism jointly leads to olfactory and memory source impairments, and these two categories of deficits are associated. These results strongly support the proposition that olfactory and confabulation measures both index orbitofrontal functioning, and suggest that olfaction could become a reliable cognitive marker in psychiatric disorders. Moreover, it underlines the need to take into account these olfactory and source memory impairments in a clinical context.
嗅觉能力现在是精神病学研究中的一个热门领域。由于眶额皮层似乎同时与气味处理和执行功能障碍有关，因此有人提出嗅觉可能是精神状态的认知标志物。虽然这一假设似乎很有希望，但很少有研究在精神病理人群中对此进行探讨。本研究旨在探索嗅觉与执行功能之间的联系。使用两个难度相当的任务来评估这些联系，一个是已知依赖于眶额皮层处理的任务（即虚构任务），另一个与该区域无关的任务（即停止信号任务）。
方法/主要发现：20 名最近戒酒后的酒精个体和 20 名配对对照者参加了一项实验，评估嗅觉能力和执行功能（即停止信号任务和虚构任务）。还控制了共病和潜在的偏差变量。与对照组相比，酒精个体在高级嗅觉处理和显著的虚构问题方面表现出受损的表现（但在停止信号任务中没有缺陷），即使考虑到共病的影响也是如此。最重要的是，嗅觉能力和虚构率在两组中均呈显著相关性。
结论/意义：酒精中毒共同导致嗅觉和记忆源损伤，这两种类型的缺陷是相关的。这些结果强烈支持了嗅觉和虚构测量都反映眶额皮层功能的观点，并表明嗅觉可能成为精神障碍的可靠认知标志物。此外，它强调了在临床环境中需要考虑这些嗅觉和源记忆损伤。
