Araneda Rodrigo, De Volder Anne G, Deggouj Naïma, Renier Laurent
Institute of Neuroscience (IoNS), Université catholique de Louvain, Brussels, Belgium.
Institute of Neuroscience (IoNS), Université catholique de Louvain, Brussels, Belgium; Department of Oto-Rhino-Laryngology & Head and Neck Surgery, Université catholique de Louvain and clinique universitaire St-Luc, Brussels, Belgium.
PLoS One. 2015 Mar 12;10(3):e0120387. doi: 10.1371/journal.pone.0120387. eCollection 2015.
Tinnitus is the perception of sound in the absence of external stimulus. Currently, the pathophysiology of tinnitus is not fully understood, but recent studies indicate that alterations in the brain involve non-auditory areas, including the prefrontal cortex. In experiment 1, we used a go/no-go paradigm to evaluate the target detection speed and the inhibitory control in tinnitus participants (TP) and control subjects (CS), both in unimodal and bimodal conditions in the auditory and visual modalities. We also tested whether the sound frequency used for target and distractors affected the performance. We observed that TP were slower and made more false alarms than CS in all unimodal auditory conditions. TP were also slower than CS in the bimodal conditions. In addition, when comparing the response times in bimodal and auditory unimodal conditions, the expected gain in bimodal conditions was present in CS, but not in TP when tinnitus-matched frequency sounds were used as targets. In experiment 2, we tested the sensitivity to cross-modal interference in TP during auditory and visual go/no-go tasks where each stimulus was preceded by an irrelevant pre-stimulus in the untested modality (e.g. high frequency auditory pre-stimulus in visual no/no-go condition). We observed that TP had longer response times than CS and made more false alarms in all conditions. In addition, the highest false alarm rate occurred in TP when tinnitus-matched/high frequency sounds were used as pre-stimulus. We conclude that the inhibitory control is altered in TP and that TP are abnormally sensitive to cross-modal interference, reflecting difficulties to ignore irrelevant stimuli. The fact that the strongest interference effect was caused by tinnitus-like auditory stimulation is consistent with the hypothesis according to which such stimulations generate emotional responses that affect cognitive processing in TP. We postulate that executive functions deficits play a key-role in the perception and maintenance of tinnitus.
耳鸣是在没有外部刺激的情况下对声音的感知。目前，耳鸣的病理生理学尚未完全了解，但最近的研究表明，大脑中的改变涉及非听觉区域，包括前额叶皮层。在实验1中，我们使用了一个“是/否”范式来评估耳鸣参与者（TP）和对照受试者（CS）在听觉和视觉模态的单峰和双峰条件下的目标检测速度和抑制控制。我们还测试了用于目标和干扰物的声音频率是否会影响表现。我们观察到，在所有单峰听觉条件下，TP比CS反应更慢且误报更多。在双峰条件下，TP也比CS反应更慢。此外，当比较双峰和听觉单峰条件下的反应时间时，CS在双峰条件下出现了预期的增益，但当使用与耳鸣匹配频率的声音作为目标时，TP没有。在实验2中，我们在听觉和视觉“是/否”任务中测试了TP对跨模态干扰的敏感性，其中每个刺激之前都有一个未测试模态的无关预刺激（例如，视觉“否/否”条件下的高频听觉预刺激）。我们观察到，在所有条件下，TP的反应时间都比CS长且误报更多。此外，当使用与耳鸣匹配/高频声音作为预刺激时，TP的误报率最高。我们得出结论，TP的抑制控制发生了改变，并且TP对跨模态干扰异常敏感，这反映了难以忽略无关刺激。最强的干扰效应由类似耳鸣的听觉刺激引起这一事实与以下假设一致，即这种刺激会产生影响TP认知处理的情绪反应。我们推测执行功能缺陷在耳鸣的感知和维持中起关键作用。
