β 波

β 波（英文：beta wave）係腦電波嘅一種。呢種波喺人類當中係指頻率處於 12.5 至 30 Hz 之間嘅腦電波，有得再細分做三種：低 Beta 波（12.5 至 16 Hz；或者叫「Beta 1」）、Beta 波（16.5 至 20 Hz；或者叫「Beta 2」）、同埋高 Beta 波（20.5 至 28 Hz；或者叫「Beta 3」）^[1]。

一般嚟講，Beta 波俾人認為佢反映咗個人正常噉醒緊而且處於一個有返噉上下精神嘅狀態（冇瞌眼瞓或者點）^[2]^[3]。

個名出自希臘字母當中嘅「β」。

功能

Beta 波同埋專注力

Beta 波最常喺個人醒緊、而且擘開咗眼嗰陣出現，而當個人合埋眼或者覺得攰、瞌眼瞓嗰陣時會變弱^[4]。
低幅、而且有住些微頻率上落嘅 Beta 波一般都俾人認為係同活躍或者焦慮嘅思考同專注有關^[5]。
額葉（frontal lobe；塊大腦皮層最近額頭嗰忽）嘅 Theta-beta 比例（theta-beta ratio）同焦慮嘅情緒成正相關^[6]：一個人愈係焦慮，佢塊額葉嘅 Theta 波幅度比 Beta 波幅度嘅比例就會愈高，反映佢個額葉（一個主管自我控制同目的嘅腦區）冇乜高頻嘅活動^[7]，所以有科學家建議 Theta-beta 比例可以攞嚟評估一個人有幾焦慮^[6]。

運動皮層嘅 Beta 波

喺運動皮層（motor cortex；主管身體郁動嘅腦區）嗰度，Beta 波同等強直郁動（isotonic movement；指肌肉長度改變但係張力不變）當中發生嘅肌肉收縮有啦掕，而喺個郁動改變之前同埋當中，運動皮層嘅 Beta 波會受壓抑^[8]。有研究顯示，當研究人員用經顱微電流刺激療法（Cranial electrotherapy stimulation）等嘅方法刺激運動皮層，令到佢多咗 Beta 波活動嗰陣時，個人嘅郁動會變得慢咗^[9]。
一吓吓嘅 Beta 活動同運動控制當中嘅感知反遣有關，而當郁動改變嗰陣會下跌^[10]。
Beta 活動喺個人要特登抗拒唔做某個動作嗰陣會上升^[11]。

同 GABA 嘅關係

喺好多情況下，Beta 波俾人認為佢反映咗由 GABA（全名「gamma aminobutyric acid」，喺哺乳類當中最緊要嗰種壓抑性神經傳遞素）所調整、壓抑某啲腦活動嘅大腦皮層傳訊。
有啲調制 GABA 受容器嘅藥－例如係 Benzodiazepines 噉－會令人類同大家鼠嘅腦電圖出現 Beta 波^[12]^[13]。
自發而且擴散式嘅 Beta 波會喺有 Dup15q 症候群嘅細路嘅頭嗰度用腦電圖量度得到。Dup15q 係一種遺傳上嘅異常，會令到個細路個腦入面某幾款嘅 GABA 受容器（GABRA5、GABRB3、同 GABRG3）數量多咗^[14]，搞到佢哋容易有自閉症或者發羊吊。所以有科學家主張喺某啲臨床情況之下，可以用 Beta 波嚟評估一個人個腦嘅某啲 GABA 活動係咪有異常^[14]。

例子

一個 28 個月大、有 Dup15q 嘅細路嘅腦電圖數據；當中度到擴散式嘅 Beta 波。

睇埋

腦電波

𝛿 波 – (0.5 – 3 Hz)
θ 波 – (4 – 7 Hz)
α 波 – (8 – 13 Hz)
μ 波 – (7.5 – 12.5 Hz)
SMR 波 – (12.5 – 15.5 Hz)
β 波 – (16 – 31 Hz)
γ 波 – (32 – 100 Hz)

參考書

Brazier, M. A. B. (1970), The Electrical Activity of the Nervous System, London: Pitman.

攷

↑ Rangaswamy M, Porjesz B, Chorlian DB, Wang K, Jones KA, Bauer LO, Rohrbaugh J, O'Connor SJ, Kuperman S, Reich T, Begleiter (2002). "Beta power in the EEG of alcoholics". Biological Psychology. 52 (8): 831–842.
↑ Dustman, R. E., Boswell, R. S., & Porter, P. B. (1962). Beta brain waves as an index of alertness. Science, 137(3529), 533-534.
↑ Miller, R. (2007). Theory of the normal waking EEG: from single neurones to waveforms in the alpha, beta and gamma frequency ranges. International journal of psychophysiology, 64(1), 18-23.
↑ Buzsáki, György (2006). Rhythms of the Brain. New York: Oxford University Press. p. 4.
↑ Baumeister J, Barthel T, Geiss KR, Weiss M (2008). "Influence of phosphatidylserine on cognitive performance and cortical activity after induced stress". NUTRITIONAL NEUROSCIENCE. 11 (3): 103–110.
↑ ^6.0 ^6.1 Putman, P., van Peer, J., Maimari, I., & van der Werff, S. (2010). EEG theta/beta ratio in relation to fear-modulated response-inhibition, attentional control, and affective traits. Biological psychology, 83(2), 73-78.
↑ Putman, P., Verkuil, B., Arias-Garcia, E., Pantazi, I., & van Schie, C. (2014). EEG theta/beta ratio as a potential biomarker for attentional control and resilience against deleterious effects of stress on attention. Cognitive, Affective, & Behavioral Neuroscience, 14(2), 782-791.
↑ Baker, SN (2007). "Oscillatory interactions between sensorimotor cortex and the periphery". Current Opinion in Neurobiology. 17 (6): 649–55.
↑ Pogosyan, A; Gaynor, LD; Eusebio, A; Brown, P (2009). "Boosting cortical activity at Beta-band frequencies slows movement in humans". Current Biology. 19 (19): 1637–41.
↑ Lalo, E; Gilbertson, T; Doyle, L; Di Lazzaro, V; Cioni, B; Brown, P (2007). "Phasic increases in cortical beta activity are associated with alterations in sensory processing in the human". Experimental brain research. Experimentelle Hirnforschung. Experimentation cerebrale. 177 (1): 137–45.
↑ Zhang, Y; Chen, Y; Bressler, SL; Ding, M (2008). "Response preparation and inhibition: the role of the cortical sensorimotor beta rhythm". Neuroscience. 156 (1): 238–46.
↑ Feshchenko, V; Veselis, R; Reinsel, R (1997). "Comparison of the EEG effects of midazolam, thiopental, and propofol: the role of underlying oscillatory systems". Neuropsychobiology. 35: 211–20.
↑ Van Lier, Hester; Drinkenburg, Wilhelmus; Van Eeten, Yvonne; Coenen, Anton (2004). "Effects of diazepam and zolpidem on EEG beta frequencies are behavior-specific in rats". Neuropharmacology.
↑ ^14.0 ^14.1 Frohlich, Joel; Senturk, Damla; Saravanapandian, Vidya; Golshani, Peyman; Reiter, Lawrence; Sankar, Raman; Thibert, Ronald; DiStefano, Charlotte; Huberty, Scott; Cook, Edwin; Jeste, Shafali (December 2016). "A Quantitative Electrophysiological Biomarker of Duplication 15q11.2-q13.1 Syndrome". PLOS One. 11: e0167179.

[1] Rangaswamy M, Porjesz B, Chorlian DB, Wang K, Jones KA, Bauer LO, Rohrbaugh J, O'Connor SJ, Kuperman S, Reich T, Begleiter (2002). "Beta power in the EEG of alcoholics". Biological Psychology. 52 (8): 831–842.

[2] Dustman, R. E., Boswell, R. S., & Porter, P. B. (1962). Beta brain waves as an index of alertness. Science, 137(3529), 533-534.

[3] Miller, R. (2007). Theory of the normal waking EEG: from single neurones to waveforms in the alpha, beta and gamma frequency ranges. International journal of psychophysiology, 64(1), 18-23.

[4] Buzsáki, György (2006). Rhythms of the Brain. New York: Oxford University Press. p. 4.

[5] Baumeister J, Barthel T, Geiss KR, Weiss M (2008). "Influence of phosphatidylserine on cognitive performance and cortical activity after induced stress". NUTRITIONAL NEUROSCIENCE. 11 (3): 103–110.

[putman1-6] 6.0 ^6.1 Putman, P., van Peer, J., Maimari, I., & van der Werff, S. (2010). EEG theta/beta ratio in relation to fear-modulated response-inhibition, attentional control, and affective traits. Biological psychology, 83(2), 73-78.

[7] Putman, P., Verkuil, B., Arias-Garcia, E., Pantazi, I., & van Schie, C. (2014). EEG theta/beta ratio as a potential biomarker for attentional control and resilience against deleterious effects of stress on attention. Cognitive, Affective, & Behavioral Neuroscience, 14(2), 782-791.

[8] Baker, SN (2007). "Oscillatory interactions between sensorimotor cortex and the periphery". Current Opinion in Neurobiology. 17 (6): 649–55.

[9] Pogosyan, A; Gaynor, LD; Eusebio, A; Brown, P (2009). "Boosting cortical activity at Beta-band frequencies slows movement in humans". Current Biology. 19 (19): 1637–41.

[10] Lalo, E; Gilbertson, T; Doyle, L; Di Lazzaro, V; Cioni, B; Brown, P (2007). "Phasic increases in cortical beta activity are associated with alterations in sensory processing in the human". Experimental brain research. Experimentelle Hirnforschung. Experimentation cerebrale. 177 (1): 137–45.

[11] Zhang, Y; Chen, Y; Bressler, SL; Ding, M (2008). "Response preparation and inhibition: the role of the cortical sensorimotor beta rhythm". Neuroscience. 156 (1): 238–46.

[12] Feshchenko, V; Veselis, R; Reinsel, R (1997). "Comparison of the EEG effects of midazolam, thiopental, and propofol: the role of underlying oscillatory systems". Neuropsychobiology. 35: 211–20.

[13] Van Lier, Hester; Drinkenburg, Wilhelmus; Van Eeten, Yvonne; Coenen, Anton (2004). "Effects of diazepam and zolpidem on EEG beta frequencies are behavior-specific in rats". Neuropharmacology.

[froh-14] 14.0 ^14.1 Frohlich, Joel; Senturk, Damla; Saravanapandian, Vidya; Golshani, Peyman; Reiter, Lawrence; Sankar, Raman; Thibert, Ronald; DiStefano, Charlotte; Huberty, Scott; Cook, Edwin; Jeste, Shafali (December 2016). "A Quantitative Electrophysiological Biomarker of Duplication 15q11.2-q13.1 Syndrome". PLOS One. 11: e0167179.

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