Describe and evaluate the synaptic homeostasis model of sleep
Essay
Describe and evaluate the synaptic homeostasis model of sleep
The synaptic homeostasis model of sleep (Tononi & Cirelli, 2003) explains memory consolidation as a by-product of synaptic downscaling that occurs during sleep. This essay will describe the synaptic homeostasis model of sleep and evaluate how valid its predictions are in the face of empirical research.
According to this model, synaptic potentiation is associated with the homeostatic regulation of slow wave activity, which is associated with synaptic downscaling. Information encoding in the day during wakefulness leads to a net increase of synaptic strength in the synapses of many brain circuits, enabling plasticity. However, this net increase in synaptic strength leads to an oversaturation of learning capacity, and takes up both a lot of space and energy. Hence, during sleep, synaptic downscaling occurs, decreasing synaptic strength globally to a sustainable level in terms of space and energy demands and enabling the reuse of these synapses for future encoding.
One prediction made by the synaptic homeostasis model is that the higher the amount of synaptic potentiation that has occurred in the previous wakefulness period, the higher the increase in slow wave activity during sleep. Huber et al (2004) asked participants to complete a visuomotor task, where subjects reached towards targets with a handheld cursor. There were two versions of the task- the rotation adaptation task, where the cursor trajectory was deviated at a certain angle, and participants would unconsciously learn and adapt to the task requirements, and the normal task, which shared the similar kinematic requirements and was subjectively indistinguishable from the rotation adaptation task. The participants completed the normal version of the task either a week before or after the rotation adaptation task. When the sleep EEG recordings from the two conditions were compared, Huber et al (2004) found a local increase in slow
Describe and evaluate the synaptic homeostasis model of sleep
The synaptic homeostasis model of sleep (Tononi & Cirelli, 2003) explains memory consolidation as a by-product of synaptic downscaling that occurs during sleep. This essay will describe the synaptic homeostasis model of sleep and evaluate how valid its predictions are in the face of empirical research.
According to this model, synaptic potentiation is associated with the homeostatic regulation of slow wave activity, which is associated with synaptic downscaling. Information encoding in the day during wakefulness leads to a net increase of synaptic strength in the synapses of many brain circuits, enabling plasticity. However, this net increase in synaptic strength leads to an oversaturation of learning capacity, and takes up both a lot of space and energy. Hence, during sleep, synaptic downscaling occurs, decreasing synaptic strength globally to a sustainable level in terms of space and energy demands and enabling the reuse of these synapses for future encoding.
One prediction made by the synaptic homeostasis model is that the higher the amount of synaptic potentiation that has occurred in the previous wakefulness period, the higher the increase in slow wave activity during sleep. Huber et al (2004) asked participants to complete a visuomotor task, where subjects reached towards targets with a handheld cursor. There were two versions of the task- the rotation adaptation task, where the cursor trajectory was deviated at a certain angle, and participants would unconsciously learn and adapt to the task requirements, and the normal task, which shared the similar kinematic requirements and was subjectively indistinguishable from the rotation adaptation task. The participants completed the normal version of the task either a week before or after the rotation adaptation task. When the sleep EEG recordings from the two conditions were compared, Huber et al (2004) found a local increase in slow