Biopsych Revision Notes PDF

Biopsych revision notes Theories of the brain Aristotle- mentalist- the mind and psyche influenced behavior Descartes- explained the brain in terms of machines- mind body problem Dualism- the philosophical position that behavior is controlled by two entities Gall- the brain is the organ of the...

Biopsych revision notes Theories of the brain Aristotle- mentalist- the mind and psyche influenced behavior Descartes- explained the brain in terms of machines- mind body problem Dualism- the philosophical position that behavior is controlled by two entities Gall- the brain is the organ of the mind- the size of the organ is a measure of its power Ways of studying the brain Cytoarchitecture- cell connectivity Neuropsychology- brain lesions such as Phineas gage Imaging techniques- MRI and fMRI- studies brain anatomy, by producing a statistical map- fMRI- good spatial resolution and poor temporal resolution EEG- electrodes- good temporal resolution and poor spatial resolution ERP- task related Stimulating techniques- transcranial magnetic stimulation (TMS)- involvement and timing- good spatial resolution and good temporal resolution Magnetic induction- used to test visual attention Action potential – all or nothing events Concentration and electrical gradient Sodium potassium pump causes an imbalance by pumping 3 positive sodium ions out of the cell and 2 positive potassium ions in the cell At rest the neuron is negatively charged (-65mV) - resting potential- if the neuron is stimulated- the resting potential becomes an action potential Action potential is generated at the axon hillock Myelinated axons conduct action potential faster that unmyelinated axons, by saltatory conduction on the nodes of Ranvier The correct balance of excitatory (EPSP) and inhibitory (IPSP) signals is necessary for the proper working of the nervous system (too active->epilepsy) ESP- released at Type I synapses IPSP- released at Type II synapses EPSPs and IPSPs are graded potentials- not all or nothing events, unlike action potentials- degrade over space and time No stimulus -> resting potential Small stimulus-> graded potential Stimulus above the threshold-> action potential Depolarization- the process by which a neuron's cell membrane potential decreases from its resting potential Repolarisation- the process by which a neuron's membrane potential returns to its resting state after an action potential Hyperpolarisation- cell's membrane potential becomes more negative Dendrite->cell body->axon->axon terminal Refractory period- the delay in response time to a second stimulus after being stimulated by a first stimulus- larger than usual stimulus to reach threshold- the cell is hyperpolarised due to the potassium leaving the cell Alcohol stimulates the GABA receptors, increasing the effect of the inhibitory neurotransmitter, leading to sedative-like effect Parkinson’s- results from a loss of dopaminergic neurons in the brain stem Different drugs affect the uptake of neurotransmitters- prolongs the effect of dopamine, leading to increase feelings of arousal Link between drug talking and reward circuits in the brain Lobe functions: Sulci and fissures- cracks and gyri-bumps Brodmann- the organization of types of neurons within the cortex Occipital lobe: visual processing Parietal lobe: touch, balance and movement Temporal lobe: hearing, speech, comprehension, memory and visual recognition Frontal lobe: movement, thinking and planning, decision making, reasoning Longitudinal fissure- separates the two lobes Sensation- the registration of physical stimuli from the environment by the sensory organs Perception- the interpretation of sensation by the brain Somatosensation Hapis (touch) Nocioception (pain and Proprioception (body temperature) awareness) Meissner’s corpuscle Slow adaptation Rapid adaptation (touch)-> Rapid Pacinian corpuscle (flutter) -> Rapid Ruffini corpuscle (vibration) -> Rapid Receptive field- sensory receptors which are sensitive to physical stimuli - Sensory receptors indicate how strong a stimulus is by the number of action potentials they fire - Stronger stimuli produce more action potentials per unit time than weaker stimuli More receptors on the hands and face compared to other areas of the body Mastication- unlocks odor from food and mixes them with- adds to flavor Synesthesia- neurological condition that causes people to experience multiple senses simultaneously when one sense is stimulated Sound Low frequency- slow vibrations and low pitch High frequency- fast vibrations and high pitch Amplitude- refers to the number of air molecules that vibrate in a sound wave- loudness is denoted by the frequency of action potentials Doppler effect- police sirens- higher pitch, low frequency, as frequency increases, distance decreases Middle ear (ear drum) transmits sound energy mechanically to the fluid filled inner ear (cochlea) Inner ear (cochlea) converts mechanical vibrations into electrical signals Bending of the basilar membrane- determines sound- the location of the bending changes the frequency Receptor neurons on different parts of the basilar memebrane respond to different frequencies of sound and form a tonotopic map Genetic mutations - Turner’s syndrome (XO)- short stature and lack of sexual development in women - CAH- abnormally high levels of circulating androgens that result in masculine phenotype of XX individuals - Androgen insensitivity syndrome (AIS) not responsive to circulating levels of androgen-> feminization of XY individuals Amygdala- motivation Hypothalamus- sexual behavior Oxytocin- promotes pair bonding during the final stages of birth Differences in cognitive abilities Male Female Spatial reasoning Verbal reasoning Explanation: hunting over large territories Explanation: formed social groups- develop tools for social communication Frontal love and corpus callosum is larger in women vs men- women more symmetrical Savic and Lindstromin (2008)- showed gay women have asymmetric brains like straight men (amygdala connects more to the sensorimotor system and striatum of the basal ganglia- action related response) and gay men have more symmetric brains like straight women (amygdala connects to areas of the brain that manifest mood, fear and anxiety) Differences in Brain structure - SCN bigger in homosexual male brain - SCN has 3x as many neurons in the male brain than the corresponding female region - SCN is 2x as large in gay men as heterosexual men - INAH3 is 2x as large in males as females - Differences in the structure of the hypothalamus may form the basis for sexual orientation and identity  - Orientation- disturbed interaction between brain development and circulating hormones? Sleep Zeitgebers- external cues Jet lag- more prevalent when travelling west to east SAD- importance of light in circadian rhythm- 60% of people report depression in northern hemisphere during winter Adolescents- delayed melatonin release Paralysed druing REM sleep- body temp. Increases- occipital lobe most active Dreaming- REM sleep Nightmares- nREM Types of LTM memory: - Episodic- personal events - Semantic- general knowledge of the world - Procedural- does not require conscious awareness e.g riding a bike Amygdala (part of the limbic system)- responsible for emotional response- Dopamine- reward Amygdala- negative emotions Serotonin- mood balance RH- negative emotions LH- positive emotions