AQA Psychology for A Level Year 2 - Student Bk

revision summaries the nervous system and the endocrine system A major physiological system that regulates behaviour. the nervous system Central nervous system Brain and the spinal cord. Peripheral nervous system Autonomic nervous system (sympathetic and parasympathetic). Somatic nervous system (body). the endocrine system Glands and hormones Hormones distributed in bloodstream. Pituitary is the master gland. Glands and hormones Hormones distributed in bloodstream. Pituitary is the master gland. Neurons and synaptic transmission Another major physiological system that regulates behaviour. Structure and function of neurons Types of neuron Motor, sensory and relay neurons. Structure of a neuron Cell body contains nucleus, has dendrites. Axon covered in myelin sheath divided by nodes of Ranvier. Electrical transmission Positive charge leads to action potential. Synaptic transmission Synapse Terminal buttons at synapse, presynaptic vesicles release neurotransmitter. Neurotransmitters Postsynaptic receptor site receives neurotransmitters from dendrites of adjoining neuron. Specialist functions, e.g. acetylcholine for muscle contraction. Excitation or inhibition Adrenaline is excitatory, serotonin is inhibitory. Psychotherapeutic drugs SSRIs increase serotonin activity. Split-brain research into hemispheric lateralisation Right and left hemisphere not connected. Split-brain research Hemispheric lateralisation Left hemisphere has different functions (e.g. language). Split-brain studies Corpus callosum cut to prevent electrical signals crossing between hemispheres. Procedure Images presented to one hemisphere at a time. Key findings Can’t describe an object in left visual field. Can recognise with left hand. Composite words: Write ‘key’ with left hand, say ‘ring’. Right hemisphere better at recognising faces. evaluation Demonstrated lateralised brain functions The left hemisphere analyses, the right hemisphere synthesises. Strengths of the methodology Standardised and controlled procedures to control input into each hemisphere. Theoretical basis Puvetti: Two minds = duality in the brain. In reality it is an integrated system. Issues with generalisation Small unrepresentative sample, with no control group. Differences in function may be overstated Distinction between hemispheres is messier than the research suggests. Localisation of function in the brain Different behaviours are controlled by specific areas of the brain. Localisation of function in the brain Localisation versus holistic theory Are brain functions in specific areas or across the whole brain? Hemispheres of the brain and the cerebral cortex Each hemisphere controls the opposite side of the body. Cortex is outer layer of the brain. Motor, somatosensory, visual and auditory centres Each of the four lobes of the brain (frontal, parietal, occipital and temporal lobes) is linked to different functions. Language centre in the brain Broca’s related to production, Wernicke’s related to understanding. evaluation Brain scan evidence of localisation Peterson et al. showed Broca and Wernicke areas active. Neurosurgical evidence Dougherty et al. : One third of OCD patients responded to cingulotomy, supports localisation. Case study evidence Phineas Gage: Personality change. Lashley’s research Rats’ maze learning unaffected by removeal of cortical material. Plasticity The law of equipotentiality (Lashley). plasticity and functional recovery of the brain after trauma The brain’s ability to change and adapt permits recovery from trauma. plasticity and functional recovery of the brain after trauma Brain plasticity Research suggests that neural connections can change or new connections can be formed. Research into plasticity Maguire et al. : Hippocampus in taxi drivers changes structure after learning the Knowledge. Draganski et al. : Changes in hippocampus and the parietal cortex before and after exams. Functional recovery of the brain after trauma Healthy brain areas take over functions of damaged areas. What happens in the brain during recovery? Axonal sprouting. Reforming of blood vessels. Recruitment of homologous brain areas. evaluation Practical application Neurorehabilitation required to maintain improvement because spontaneous recovery slows down. Negative plasticity Drug use may cause neural changes (Medina et al. ). Phantom limb syndrome due to reorganisation in somatosensory cortex (Ramachandran). Age and plasticity Plasticity reduces with age, though Bezzola et al. showed how golf training caused neural changes in over 40s. Support from animal studies Hubel and Wiesel: Pioneering research into kittens’ cortical response, caused permanent damage. The concept of cognitive reserve Schneider et al. : The more time spent in education, the greater the brain’s capacity to heal. Chapter 2 Biopsychology 54 •