Knott V, Lapierre Y, Griffiths L, de Lugt D, Bakish D
Department of Psychiatry and Psychology, University of Ottawa, Canada.
J Affect Disord. 1991 Sep;23(1):43-8. doi: 10.1016/0165-0327(91)90034-p.
Depressive episodes have been frequently characterized by deficits in information processing efficiency which are particularly evident when required to sustain or focus attention. As cerebral event-related potentials (ERPs) have been shown to reflect various aspects of selective attention and attentional dysfunction, this study attempted to examine ERPs in depressed patients performing a selective auditory attention task. Twenty-nine patients with a diagnosis of major depressive disorder (DSM-III) and 15 normal, non-psychiatric controls served as experimental subjects. Auditory potentials were recorded from the vertex of subjects who listened selectively to a series of tone pips in one ear and ignored concurrent tone pips to the other ear. Tone pips were delivered at short (320-500 ms) interstimulus intervals and subjects were required to detect, within the attended ear, rare 'target' tones of a different pitch than the more frequent 'standard' tones. In addition to behavioral indices of 'hits' and 'false alarms', ERP-derived measures included N1 amplitudes to attended and ignored stimuli, 'coefficients of attention' as calculated from N1 amplitude ratios and the latency onset and amplitude of the 'negative difference' (Nd) wave resulting from the subtraction of attended and ignored waveforms. Behavioral measures indicated that depressed patients were as efficient as controls in task performance and in fact they exhibited a significant left ear advantage in the additional task. Although a significant 'N1 effect' was observed with attended tones eliciting larger amplitudes than unattended tones, ERP measures of selective attention did not tend to differentiate the two groups.
抑郁发作常常表现为信息处理效率低下，在需要持续或集中注意力时尤为明显。由于大脑事件相关电位（ERP）已被证明能反映选择性注意和注意功能障碍的各个方面，本研究试图检测抑郁症患者在执行选择性听觉注意任务时的ERP。29名被诊断为重度抑郁症（DSM-III）的患者和15名正常的非精神科对照者作为实验对象。从受试者头顶记录听觉电位，受试者选择性地听一只耳朵中的一系列短音，并忽略同时传入另一只耳朵的短音。短音以短的（320 - 500毫秒）刺激间隔呈现，受试者需要在被关注的耳朵中检测出与更频繁出现的“标准”音调音高不同的罕见“目标”音调。除了“命中”和“误报”的行为指标外，从ERP得出的测量指标包括对被关注和被忽略刺激的N1波幅、根据N1波幅比率计算的“注意系数”以及由被关注和被忽略波形相减得到的“负向差异”（Nd）波的潜伏期起始和波幅。行为测量表明，抑郁症患者在任务表现上与对照组一样高效，事实上他们在附加任务中表现出显著的左耳优势。尽管观察到了显著的“N1效应”，即被关注的音调比未被关注的音调引发更大的波幅，但选择性注意的ERP测量指标并没有区分两组的倾向。
