P50 係事件相關電位(event-related potential)嘅一種,出現喺接收到一個刺激(通常係一吓聲響)之後大約 50 至 60 毫秒[1],好多時出現喺顳葉(temporal lobe;主管聽覺嘅腦葉)嗰頭[2]。對 P50 嘅研究好多時會視佢為代表感覺門控(sensory gating)嘅腦活動-感覺門控係指個腦有能力選擇性噉篩走一部份所收到嘅感覺訊息(例如係喺一個好多人好嘈嘅集會當中集中精神淨係聽身邊嗰個人講嘢),而如果一個受試者對於某一個聽覺刺激冇 P50 嘅反應,就表示佢個腦嘅感覺門控機制喺度發揮效用,令佢接收唔到嗰個刺激[3]。
有研究顯示,P50 仲可以用嚟預測同診斷某啲心理病,例如係精神分裂症嘅患者就出現唔能夠正確噉做 P50 嘅現象(即係好多時會唔受控噉接收好多唔應該接收嘅刺激)[4][5][6]。除咗精神分裂之外,外傷性腦損傷嘅病人、娛樂性用藥、同埋有創傷後心理壓力緊張症候群(PTSD)嘅病人都有 P50 失調嘅情況[7]。
- ↑ Nathan Zasler; Douglas Katz, MD; Ross D. Zafonte (2007). Brain Injury Medicine: Principles and Practice. Demos Medical Publishing. pp. 160–161.
- ↑ Korzyukov, O., Pflieger, M. E., Wagner, M., Bowyer, S. M., Rosburg, T., Sundaresan, K., ... & Boutros, N. N. (2007). Generators of the intracranial P50 response in auditory sensory gating. Neuroimage, 35(2), 814-826.
- ↑ Huotilainen, M., Winkler, I., Alho, K., Escera, C., Virtanen, J., Ilmoniemi, R. J., ... & Näätänen, R. (1998). Combined mapping of human auditory EEG and MEG responses. Electroencephalography and Clinical Neurophysiology/Evoked Potentials Section, 108(4), 370-379.
- ↑ Clementz, B. A., Blumenfeld, L. D., & Cobb, S. (1997). The gamma band response may account for poor P50 suppression in schizophrenia. Neuroreport, 8(18), 3889-3893.
- ↑ Michael S. Ritsner (21 April 2009). The Handbook of Neuropsychiatric Biomarkers, Endophenotypes and Genes: Volume I: Neuropsychological Endophenotypes and Biomarkers. Springer. p. 120.
- ↑ Christoph Mulert; Louis Lemieux (29 October 2009). EEG - fMRI: Physiological Basis, Technique, and Applications. Springer. p. 84.
- ↑ Michelle de Haan (15 April 2013). Infant EEG and Event-Related Potentials. Psychology Press. p. 240.