Biopsychology

• The nervous system is made up of the brain and the spinal cord
• The peripheral nervous system (PNS) relays messages from the environment to the CNS via sensory neurones and from the CNS to effectors via motor neurones
• The PNS is subdivided into the autonomic nervous system (controls involuntary vital functions) and the somatic nervous system (receives information from sensory receptors and stimulates effectors)
• The autonomic nervous system has sympathetic and parasympathetic branches that work in an antagonistic pair during the 'rest and digest' response
• The endocrine system is the main chemical messenger system of the body, where hormones are secreted into the bloodstream from glands and transported towards target cells
• The pituitary gland controls the release of hormones from all other glands in the body
• The fight or flight response involves sensory receptors sending information to the hypothalamus, triggering increased activity in the sympathetic branch of the ANS
• Adrenaline is released from the adrenal medulla, creating physiological arousal needed for the fight or flight response
• The parasympathetic branch decreases activity increased by the sympathetic branch, triggering the rest and digest response
• Synaptic transmission is a method of neurons communicating with each other
• An action potential causes depolarisation, leading to the release of neurotransmitters into the synaptic cleft
• Neurotransmitters can have inhibitory (e.g. serotonin) or excitatory (e.g. dopamine) effects
• Localisation theory suggests certain areas of the brain are responsible for specific processes, behaviours, and activities
• Motor area in the frontal lobe regulates and coordinates movements
• Auditory area in the temporal lobe processes auditory information and speech
• Visual area in the occipital lobe processes visual information
• Somatosensory area in the parietal lobe processes information associated with the senses
• Wernicke's Area in the left temporal lobe is responsible for speech comprehension
• Broca's Area in the left frontal lobe is responsible for speech production
• Left hemisphere of the brain is associated with language production and comprehension
• Plasticity refers to the brain's ability to adapt and change in response to trauma, new experiences, and learning
• Functional recovery allows the brain to transfer functions of damaged areas to healthy parts, enabling normal functioning
• Negative plasticity can result in painful consequences, while positive plasticity can lead to desirable outcomes
• Neuroplasticity occurs in animals too
• Hubel and Weisel (1970) sutured the right eye of kittens, who are blind from birth, for a period of 6 months, opening the eyes and several points and monitoring brain activity in the visual cortex
• Activity in the left visual cortex was observed, corresponding to the development of occular dominance columns
• During high susceptibility periods, eye closure for 3-4 days led to a decline in the number of cells that can be driven from both eyes
• Cognitive reserve may increase the rate of functional recovery
• Cognitive reserve is the level of education a person has attained and how long they have been in education
• Increased cognitive reserve increases the likelihood of making a disability-free recovery after trauma, due to increased rates of neuroplasticity
• Individuals with more years of education may have developed the ability to form neuronal connections at a high rate, leading to high levels of functional recovery
• Limits to spontaneous and functional recovery
• After trauma, the brain activates secondary neural circuits to reinstate normal function
• Motor therapy or electrical stimulation may be needed beyond a specific point for further recovery
• Constraint-induced movement therapy improved motor performance in stroke patients significantly
• Hemispheric lateralisation
• Each hemisphere of the brain is mainly responsible for certain behaviours, processes, and activities
• The right hemisphere controls the left side of the body, and vice versa
• Split-brain research on epileptic patients demonstrated lateralised functions of the two hemispheres
• Left hemisphere is dominant for language tasks, while the right hemisphere is dominant for visuo-spatial tasks