Biopsychology

• The central nervous system is made up of the brain and the spinal cord and is responsible for conscious awareness.
• The somatic nervous system is the part of the nervous system that controls voluntary movements. It also transmits sensory information to the CNS.
• The autonomic nervous system controls involuntary movements and plays a role in homeostasis.
• The autonomic and the somatic nervous systems make up the peripheral nervous system.
• The autonomic nervous system has two sub categories within it. The parasympathetic nervous system calms the body down to its normal resting state. The sympathetic nervous system readies the body for action, otherwise known as the fight or flight response.
• Sensory neurons carry information from the senses to the CNS, to be felt as sensations. Motor neurons control movement through the release of neurotransmitters. Relay neurons allow communication between the motor and the sensory neurons.
• Synaptic transmission is where an electrical impulse is passed down the neuron as action potential. At the axon terminal the vesicles (containing the neurotransmitter) reach the synaptic cleft/gap. Vesicles release the neurotransmitter and they bind to receptor sites on the postsynaptic cell. Excitatory or inhibitory effects occur on the postsynaptic cell.
• Which region of the peripheral nervous system is known as the fight or flight response?

  Sympathetic nervous system
• Excitatory neurotransmitters make the postsynaptic cell more likely to fire e.g adrenaline. Inhibitory neurotransmitters make the postsynaptic cell less likely to fire e.g Noradrenaline
• The hypothalamus stimulates the release of hormones from the pituitary gland. The pituitary gland is labelled as the master gland and its hormones stimulate other glands to secrete. The pituitary gland has two lobes, the anterior and the posterior. A key hormone that is released from the anterior lobe triggers ACTH which triggers the release or cortisol.
• The pineal gland secretes melatonin, which is responsible for biological rhythms like the sleep wake cycle. The thyroid gland secretes thyroxine and regulates metabolism. The adrenal glands are made up of the adrenal medulla, which releases adrenaline and noradrenaline, and the adrenal cortex, which releases cortisol.
• The SAM pathway stands for the sympathomedullary pathway, and is otherwise known as the fight or flight response.
• The SAM pathway is triggered by a stressor. This then activates the amygdala which sends a distress signal to the hypothalamus gland. The hypothalamus gland activates the SAM to stimulate the sympathetic nervous system and therefore the adrenal medulla. The adrenal medulla secretes adrenaline and noradrenaline, which cause physiological changes.
• A limitation to the fight or flight response is the freeze response discovered by Gray. This response causes hyper vigilance. This is important because it highlights that the 2 responses are limited.
• Fight or flight also has gender bias. Taylor et al found that women tend and befriend in stressful situations, and form alliances with other women as a response. This shows the F or F response is beta bias, and that it is androcentric.
• Another limitation to the F or F response is that it may not be needed from an evolutionary standpoint. This is due to humans coming across stressful dangerous situations less often in modern civility.
• Localisation of function is the idea that certain functions have certain locations in the brain.
• The motor area is located in the frontal lobe. It controls voluntary movements. It is is both hemispheres.
• The somatosensory area in located in the parietal lobes and converts sensory information into sensations. It is in both hemispheres.
• The visual area in located in the occipital lobes and receives visual information. Sub sections can interpret shapes and colours. It is located in both hemispheres with the left visual field being processed in the right hemisphere and vis versa.
• The auditory area is located in the temporal lobe and analyses and processes acoustic information. It is in both hemispheres, but information from the left ear is processed primarily in the right hemisphere and vis versa.
• The Broca's area is responsible for language production and is found in the left frontal lobe. Found due to Broca's patient Tan.
• The Wernicke's area is responsible for language comprehension and is found in the left temporal lobe.
• Sperry and Gazzangia (1964) investigated the extent to which the 2 hemispheres are specialised.
• There is an idea that the two hemispheres of the brain are functionally different. The right hemisphere relates to visual and motor tasks, while the left is associated with language.
• Sperry and Gazzangia had 3 variations in the study. Describe what you see, tactile test and a drawing test.
• The corpus collosum are nerve fibres that facilitate interhemispheric communication.
• A strength of S and G split brain research is that it was highly controlled, meaning extraneous variables were controlled and there was a clear cause and effect relationship. However, the lab setting meant that it lacked ecological validity, for example one of the PS eyes was covered.
• A limitation of S&G split brain research is that it had a very limited and unique sample. They all had epilepsy, where on some sort of medication and had undergone hemispheric surgery. This classed the study as idiographic meaning it can't be fully generalisable to the rest of the population.
• Rodgers et al (2004) supports S&G split brain research. He found a chicken that could carry out duel tasks (looking for food and watching out for predators). It provided evidence that split brain patients have enhanced cognitive ability and that each hemisphere is separately functionally different.
• Brain plasticity is the brains ability to change and adapt because of experience.
• Functional recovery is the transfer of functions to an undamaged area of the brain post trauma. It achieve this through neuronal unmasking, uses dormant synapses to open connections to compensate for nearby damage.
• Synaptic pruning is the deletion of unused neural pathways.
• Evidence for brain plasticity: Kuhn - Increased grey matter in people who consistently played video games. Davidson- Buddhist monks, meditation permenant brain change.
• A strength of research into brain plasticity is the application into neurorehabilitation.
• Spatial resolution is how accurate the scans unit of measurement is. Greater spatial resolution means psychologists can discriminate between brain regions better.
• Temporal resolution if the accuracy of a scan in relation to time. Greater temporal validity helps to determine the accuracy of onset brain activity.