Kähkönen Seppo, Ahveninen Jyrki, Pekkonen Eero, Kaakkola Seppo, Huttunen Juha, Ilmoniemi Risto J, Jääskeläinen Iiro P
Cognitive Brain Research Unit, Department of Psychology, University of Helsinki, Helsinki, Finland.
Clin Neurophysiol. 2002 Dec;113(12):1894-902. doi: 10.1016/s1388-2457(02)00305-x.
Dopaminergic function has been closely associated with attentional performance, but its precise role has remained elusive.
Electrophysiological and behavioral methods were used to assess the effects of dopamine D2-receptor antagonist haloperidol on involuntary attention shifting using a randomized, double-blind, placebo-controlled cross-over design. Eleven subjects were instructed to discriminate equiprobable 200 and 400ms tones in a forced-choice reaction-time (RT) task during simultaneous measurement of whole-head magnetoencephalography and high-resolution electroencephalography.
Occasional changes in task-irrelevant tone frequency (10% increase or decrease) caused marked distraction on behavioral performance, as shown by significant RT increases to deviant stimuli and subsequent standard tones. Furthermore, while the standard tones elicited distinct P1-N1-P2-N2-P3 waveforms, deviant tones elicited additional mismatch negativity (MMN), P3a, and reorienting negativity (RON) responses, indexing brain events associated with involuntary attention shifting. While haloperidol did not affect the source loci of the responses of magnetic N1 and MMN, the amplitude of the electric P3a and that of RON were significantly reduced and the latency of magnetic RON were delayed following haloperidol administration.
The present results suggest that dopamine modulates involuntary attention shifting to task-irrelevant deviant events. It appears that dopamine may disrupt the subsequent re-orienting efforts to the relevant task after distraction.
多巴胺能功能与注意力表现密切相关，但其确切作用仍不明确。
采用电生理和行为学方法，使用随机、双盲、安慰剂对照的交叉设计，评估多巴胺D2受体拮抗剂氟哌啶醇对非自愿注意力转移的影响。11名受试者在同时测量全脑磁脑电图和高分辨率脑电图时，被要求在强制选择反应时（RT）任务中区分等概率的200和400毫秒音调。
任务无关音调频率的偶尔变化（增加或减少10%）会对行为表现造成明显干扰，表现为对异常刺激和随后标准音调的反应时显著增加。此外，虽然标准音调引发了明显的P1-N1-P2-N2-P3波形，但异常音调引发了额外的失配负波（MMN）、P3a和重新定向负波（RON）反应，这些反应标志着与非自愿注意力转移相关的脑电活动。虽然氟哌啶醇不影响磁N1和MMN反应的源位置，但给药后电P3a和RON的振幅显著降低，磁RON的潜伏期延迟。
目前的结果表明，多巴胺调节对任务无关异常事件的非自愿注意力转移。似乎多巴胺可能会在注意力分散后干扰随后对相关任务的重新定向努力。
