Why do we feel sleepy during boring classes?
Sleep is a physiological process required for normal intellectual function, consolidation of memory, rest for the musculoskeletal system, decreasing energy expenditure and also replenishing the storage reserves. Sleep allows learning and memory to function properly and reinforces what we learn during the day. This is the reason why students should have adequate sleep especially before exams.
Sleep results from the complex interaction of multiple neurotransmitter systems. Sleep is regulated by the Ventrolateral Preoptic Nucleus (VLPO) region located in the anterior Hypothalamus which in turn is controlled by the complex neural and hormonal mechanisms. The VLPO becomes active during sleep and uses the inhibitory neurotransmitters GABA to initiate sleep by inhibiting the arousal regions of the brain. There is also a biological clock with in our body called the circadian rhythm which is regulated by the suprachiasmatic nucleus and the hormone, Melatonin. This helps in the normal sleep–wake cycle, body temperature and secretion of hormones depending on the time of the day.
One of the important mechanisms that keeps us awake is the Ascending Reticular Activating System (ARAS) which collects the inputs from all sensory organs (Eating, Vision, Hearing and Smell etc.) and keeps activating our brain thus making us awake and alert. During the process of sleep, the signal from the ARAS is switched-off, so that the person is unaware of the external stimuli.
In a boring class room session, the student himself withdraws from the external stimulus and gradually goes to sleep. This reduces the sensory input and also activates the sleep centre. The brain gradually becomes less responsive to visual, auditory, and other environmental stimuli during the transition from wake to sleep, which is considered to be stage I of sleep. There can be other factors which are additive to this process such as sleep deprivation the previous day, certain medications, excessive physical exercise etc.
Adolescents(10-17 years) require 8.5-9.25 hours of sleep per day. But if a person gets regular excessive day time sleepiness, then it is better to consult a sleep specialist.
Dr. SELVA SEETHARAMAN S.
Consultant Plastic Surgeon
SRM Institute of Medical Sciences (SIMS)