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Brain Waves: Difference between revisions
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[[File:Brain-Frequency-Chart.jpg|thumb|Brain Frequency Chart]] | |||
At the root of all our thoughts, emotions and behaviours is the communication between [[Neurons]] within our [[Brain]]s called [[Brain Waves]]. Brain waves are produced by synchronised electrical pulses from masses of neurons communicating with each other. | At the root of all our thoughts, emotions and behaviours is the communication between [[Neurons]] within our [[Brain]]s called [[Brain Waves]]. Brain waves are produced by synchronised electrical pulses from masses of neurons communicating with each other. | ||
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Each serves a purpose to help us cope with various situations – whether it is to help us process and learn new information or help us calm down after a long stressful day. The five brain waves in order of highest frequency to lowest are as follows: gamma, beta, alpha, theta, and delta.<ref>[http://mentalhealthdaily.com/2014/04/15/5-types-of-brain-waves-frequencies-gamma-beta-alpha-theta-delta/ Mental Health Daily]</ref> | Each serves a purpose to help us cope with various situations – whether it is to help us process and learn new information or help us calm down after a long stressful day. The five brain waves in order of highest frequency to lowest are as follows: gamma, beta, alpha, theta, and delta.<ref>[http://mentalhealthdaily.com/2014/04/15/5-types-of-brain-waves-frequencies-gamma-beta-alpha-theta-delta/ Mental Health Daily]</ref> | ||
==Neural | ==Neural Oscillations== | ||
[[Neural Oscillations]] have been most widely studied in neural activity generated by large groups of neurons. Large-scale activity can be measured by techniques such as EEG. In general, EEG signals have a broad spectral content similar to pink noise, but also reveal oscillatory activity in specific frequency bands. The first discovered and best-known frequency band is alpha activity (7.5–12.5 Hz) that can be detected from the occipital lobe during relaxed wakefulness and which increases when the eyes are closed. Other frequency bands are: delta (1–4 Hz), theta (4–8 Hz), beta (13–30 Hz) and gamma (30–70 Hz) frequency band, where faster rhythms such as gamma activity have been linked to cognitive processing. Indeed, EEG signals change dramatically during sleep and show a transition from faster frequencies to increasingly slower frequencies such as alpha waves. In fact, different sleep stages are commonly characterized by their spectral content. Consequently, neural oscillations have been linked to cognitive states, such as awareness and consciousness.<ref>[https://en.wikipedia.org/wiki/Neural_oscillation Neural Oscillation]</ref> | [[Neural Oscillations]] have been most widely studied in neural activity generated by large groups of neurons. Large-scale activity can be measured by techniques such as EEG. In general, EEG signals have a broad spectral content similar to pink noise, but also reveal oscillatory activity in specific frequency bands. The first discovered and best-known frequency band is alpha activity (7.5–12.5 Hz) that can be detected from the occipital lobe during relaxed wakefulness and which increases when the eyes are closed. Other frequency bands are: delta (1–4 Hz), theta (4–8 Hz), beta (13–30 Hz) and gamma (30–70 Hz) frequency band, where faster rhythms such as gamma activity have been linked to cognitive processing. Indeed, EEG signals change dramatically during sleep and show a transition from faster frequencies to increasingly slower frequencies such as alpha waves. In fact, different sleep stages are commonly characterized by their spectral content. Consequently, neural oscillations have been linked to cognitive states, such as awareness and consciousness.<ref>[https://en.wikipedia.org/wiki/Neural_oscillation Neural Oscillation]</ref> | ||
==Frequency response== | ==Frequency response== | ||
In response to input, a neuron or neuronal ensemble may change the frequency at which it oscillates, thus changing the rate at which it spikes. Often, a neuron's firing rate depends on the summed activity it receives. Frequency changes are also commonly observed in central pattern generators and directly relate to the speed of motor activities, such as step frequency in walking. However, changes in relative oscillation frequency between different brain areas is not so common because the frequency of oscillatory activity is often related to the time delays between brain areas.<ref>[https://en.wikipedia.org/wiki/Neural_oscillation Neural Oscillation]</ref> | In response to input, a neuron or neuronal ensemble may change the frequency at which it oscillates, thus changing the rate at which it spikes. Often, a neuron's firing rate depends on the summed activity it receives. Frequency changes are also commonly observed in central pattern generators and directly relate to the speed of motor activities, such as step frequency in walking. However, changes in relative oscillation frequency between different brain areas is not so common because the frequency of oscillatory activity is often related to the time delays between brain areas.<ref>[https://en.wikipedia.org/wiki/Neural_oscillation Neural Oscillation]</ref> | ||
==Alpha Waves== | ==Alpha Waves== | ||