Biopsychology
- Created by: beckyyatess
- Created on: 07-07-18 14:29
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- Biopsychology
- The Nervous System
- THE NS - specialised network of cells in the human body and is our primary internal communication system.
- CENTRAL NERVOUS SYSTEM - made up of the brain and spinal cord
- SPINAL CORD - transfers messages to and from the brain and the rest of the body - also responsible for simple reflex actions
- THE BRAIN - provides conscious awareness and is involved in all psychological processes - brain stem connects brain and spinal cord and control involuntary processes
- PERIPHERAL NERVOUS SYSTEM - PNS transmits messages via millions of neurons to and from the CNS.The PNS is further divided into the autonomic nervous system and the somatic nervous system
- SOMATIC NERVOUS SYSTEM - maintains communication between central nervous system abd outside world. Consists of: 1. Sensory pathways: carry info to spinal cord and brain 2. Motor Pathways: allow brain to control movement
- AUTONOMIC NERVOUS SYSTEM - plays an important role in homeostatis - it only consists of motor pathways
- SYMPATHETIC NERVOUS SYSTEM - prepares body for fight/flight response Eg. increases blood pressure, heart rate, dilates pupils etc
- PARASYMPATHETIC NERVOUS SYSTEM - returns body to normal resting state - opposite actions to sympathetic nervous system
- CENTRAL NERVOUS SYSTEM - made up of the brain and spinal cord
- THE NS - specialised network of cells in the human body and is our primary internal communication system.
- The Endocrine System
- HYPOTHALAMUS - control release of hormones in pituitary gland and regulates endocrine system
- PITUITARY GLAND - control release of hormones from other glands
- ACTH - released by anterior lobe - stimulates the adrenal cortex and release of cortisol
- OXYTOCIN - released by posterior lobe - responsible for uterus contractions in child birth
- PINEAL GLAND
- MELATONIN - responsible for important biological rhythms including sleep/wake cycle.
- THYROID GLAND
- THYROXINE- responsible for the regulation of metabolism
- ADRENAL GLANDS - helps trigger the fight/flight response
- ADRENALINE AND NORADRENALINE - released by adrenal medulla - plays key role in fight/flight response
- CORTISOL - released by adrenal cortex - stimulates release of glucose whilst suppressing the immune system
- OVARIES
- OESTROGEN - controls regulation of female reproductive system including menstrual cycle and pregnancy
- TESTES
- ANDROGENS - eg. testosterone - responsible for development of male characteristics during puberty/ muscle growth
- Structure and Function of neurons
- CELL BODY - includes nucleus which contains genetic material
- DENTRITES - branch off nerve cell to connect whith other neurons - carry impulses towards cell body
- AXON TERMINAL - send impulse to next neuron across synapse - contain tiny sacs called neurotransmitters
- THE AXON - carries nerve impulses away from cell body
- NODES OF RANVIER - gaps in myelin sheath - increase speed of electrical impulase
- THE MYELIN SHEATH - Insulates and protects the axon and helps speed up electrical transmission
- FIGHT/FLIGHT Evaluation
- 1 - Human behaviour is not limited to only 2 responses
- Gray - suggests first response to danger is to avoid it all together ("Freeze" response)
- Humans are hypervigilant while they assess a situation - suggest that fight/flight response explanation of behaviour is limited - doesn't fuly explain complex cognitive and biological factors
- Gray - suggests first response to danger is to avoid it all together ("Freeze" response)
- 2 - doesn't fully explain stress response in females
- Taylor et al - suggests females adopt a tend and befriend response in stressful situations - women are more likely to protect their offspring and form alliances with other women
- Highlights a beta-bias in this area of psychology because psychologists assumed that females responded in the same way as males - limited application in females
- Taylor et al - suggests females adopt a tend and befriend response in stressful situations - women are more likely to protect their offspring and form alliances with other women
- 3 - can have negative / detrimental effect on health
- modern life rarely requires such an intense biological response - this matters because the activation of this response can increase blood pressure, cause damage to blood vessels and contribute to heart disease - maladaptive to everyday life
- 1 - Human behaviour is not limited to only 2 responses
- Lateralisation of function - the idea that 2 hemispheres have different functions
- Left - dominant for language, logical and analytical thought and complex movements
- Right - dominant for non-linguistic functions eg. face recognition, music, emotion and intuition
- Split-brain research - Sperry - to demonstrate that hemispheres have different functions and each hemisphere has its own conscious awareness and memory
- NATURAL EXPERIMENT - 11 male participants (epileptics who had all undergone commisectory
- VISUAL STIMULI TESTS - slides projected either side of a fixation point at rate of one picture per 1/10 second - participants say/write what they have seen
- Results and objects only recognised when presented to same eye (evidence for 2 sperate memories
- VISUAL STIMULI TESTS - slides projected either side of a fixation point at rate of one picture per 1/10 second - participants say/write what they have seen
- NATURAL EXPERIMENT - 11 male participants (epileptics who had all undergone commisectory
- Evaluation
- Evidence - Sperry's pioneering work has produced and impressive and sizable body of research findings - support Sperrys conclusion of functions of left and right hemispheres
- Methodological strengths - highly specialised and standardised procedures - short amount of time looking as pictures meant that pp couldn't ajust visual field so only one hemisphere was receiving info at one time
- Theoretical basiss - prompted philosophical debate about degree of communication between 2 hemispheres in everyday functioning - some think two hemispheres behave independently whereas others believe they act together
- Synaptic transmission
- Nerve impulse travels down axon and arrives at presynaptic terminal
- vesicles release their neurotransmitter across the synapse
- this chemical then locks into special recptor sites of the adjacent neuron (post synaptic recptor sites)
- Enzymes are released to break down excess neurotransmitter
- OR excess neurotransmitter is reabsorbed by synaptic terminals where it was released
- vesicles are replenished with new and reused neurotransmitters ready for the next impulse
- OR excess neurotransmitter is reabsorbed by synaptic terminals where it was released
- Enzymes are released to break down excess neurotransmitter
- this chemical then locks into special recptor sites of the adjacent neuron (post synaptic recptor sites)
- vesicles release their neurotransmitter across the synapse
- Nerve impulse travels down axon and arrives at presynaptic terminal
- Localisation of function
- the idea that different parts of the brain perform different tass and are involved with different parts of the body
- Right hemisphere mostly responsible for left side of the body
- left hemisphere mostly responsible for right side
- VISUAL - occipital lobe
- AUDITORY - Temporal lobe
- SOMATO SENSORY - Parietal lobe
- integrates info to and from different senses and important role in spatial navigation - causes lack of skin sensation if damaged
- Speech production - Brocas area (left frontal lobe) - converting memories and thoughts into words - damage = Broca's aphasia - speech is slow and lacking in fluency
- Speech comprehension - Wernicke's area (left temporal lobe) - comprehension or recognition of spoken words - damage = Wernicke's aphasia - difficulty understanding what others say
- Processes sound - causes partial and total deafness if damaged
- SOMATO SENSORY - Parietal lobe
- MOTOR - frontal lobe
- controls body movement - damages causes impaired movement
- AUDITORY - Temporal lobe
- EVIDENCE FOR LOCALISATION OF FUNCTION
- Many lab studies using brain scans show how blood flow is concentrated in regions where tasks are performed
- eg. Dougherty et al - reported on 44 OCD patients who had undergone a cingulotomy (procedure that involves lessoning of the cingulate gyrus)P - at post surgical follow up after 32 weeks one third met the criteria for successful response to the surgery and 14% for partial response - suggest behaviours associated with disorders alike are localised
- Many lab studies using brain scans show how blood flow is concentrated in regions where tasks are performed
- EVIDENCE AGAINST LOCALISATION OF FUNCTION
- HOLISTIC FUNCTIONING - although some functions are located in certain areas of the brain, most functions involves many interconnected areas of the brain
- people with damage to a specific area often recover functioning over time because another area of the brain takes over - referred to as brain plasticity
- the idea that different parts of the brain perform different tass and are involved with different parts of the body
- Brain plasticity - refers to the brains ability to change and adapt as a result of experience
- Research into brain plasticity: MAGUIRE ET AL
- the role of the hippocampus is to facilitate spatial memory in the form of navigation
- Taxi drivers undergo extensive training known as "The knowledge" and therefore make an ideal group for study of spatial navigation
- Aim: to examine whether structural changes could be detected in the brains of people with extensive experience of spatial navigation
- Method: Structural MRI scans were obtained - 16 right-handed London taxi drivers - all had been driving for more than 1.5 years - scans of healthy, right handed males who did not drive taxis as control group
- Findings - significantly more grey matter posterior hippocampus of taxi drivers than control group
- Method: Structural MRI scans were obtained - 16 right-handed London taxi drivers - all had been driving for more than 1.5 years - scans of healthy, right handed males who did not drive taxis as control group
- Aim: to examine whether structural changes could be detected in the brains of people with extensive experience of spatial navigation
- Taxi drivers undergo extensive training known as "The knowledge" and therefore make an ideal group for study of spatial navigation
- the role of the hippocampus is to facilitate spatial memory in the form of navigation
- Evaluation
- Practical application - has contributed to field of neurorehabilitation - although the brain may have capacity to fix itself to a point, this process requires further intervention to be completely successful
- Negative plasticity - maladaptive behavioural consequences - eg. prolonged drug use results in poorer cognitive function and increased risk of dementia later in life
- Age and plasticity - plasticity tends to reduce with age - in childhood its constantly adapting due to many new experiences and learning
- Research into brain plasticity: MAGUIRE ET AL
- Functional recovery - unaffected areas of the brain are often able to adapt and compensate for areas that are damaged
- Brain is able to rewire and reorganise itself by forming new synaptic connections close to the are of damage
- Secondary neural pathways would not be used typically to carry out certain functions are activated enable functioning to continue
- Supported by a number of structural changes in brain:
- Axonal sprouting : growth of new nerve endings which connect the undamaged nerve cells to form new neuronal pathways
- Reformation of blood vessels
- Recruitment of homologous (similar) areas ont he opposite side of the brain to perform specific tasks - eg. Broca's area damaged on left side of brain , right side equivalent would carry out its functions
- Supported by a number of structural changes in brain:
- Secondary neural pathways would not be used typically to carry out certain functions are activated enable functioning to continue
- Brain is able to rewire and reorganise itself by forming new synaptic connections close to the are of damage
- Ways of studying the brain
- POST-MORTEMS - analysis of persons brin after death
- + = vital in providing a foundation for early understanding of key processes - allow examinations of deep regions of the brain - allow for a more detailed examination of the anatomical and neurochemical areas of the brain
- - = causation - ethical issues, may not be able to give informed consent eg. HM
- FUNCTIONAL MAGNETIC RESONANCE IMAGINING (fMRI) - method used to measure persons brain activity whilst doing a task - detects blood oxygenation
- + = no radiation needed - risk free - non-invasive - straightforward to use - high spatial resolution
- - = expensive - need to be perfectly still - poor temporal resolution
- EVENT-RELATED POTENTIALS (ERPs) - brains electrophysiological response to a specific, cognitive or motor event can be isolated through analysis of EEG data
- + = much more specificity than EEG - excellent temporal resolution
- - = lack of standardisation in ERP methodology between different research studies - elimination of background noise and extraneous data is not always easy to achieve
- POST-MORTEMS - analysis of persons brin after death
- Biological Rhythms
- INFRADIAN - last longer than 24 hours - female menstrual cycle
- Female reproductive system regulated by hormones - ovulations occurs roughly halfway through cycle when oestrogen levels are highest - usually lasts for 16-32 hrs - after ovulation progesterone levels increase ready for possible embryo implantation - cycle approx 28 days
- SAD - seasonal affective disorder - changes in eating habits , lowered moods - related to changing patterns of light - affect circadian rhythms which changes mood - serotonin levels low due to less light - treated with light therapy an, SSRI's and psychotherapy - melatonin released affects production of serotonin
- Advantageous for mothers cycles to be synced and fall pregnant at the same time as babies could be cared for collectively so increases child's chance of survival
- Methodological issues such as many factors that influence women's menstrual cycle
- Female reproductive system regulated by hormones - ovulations occurs roughly halfway through cycle when oestrogen levels are highest - usually lasts for 16-32 hrs - after ovulation progesterone levels increase ready for possible embryo implantation - cycle approx 28 days
- ULTRADIAN - last less than 24 hours eg. human sleep - this cycle alternated between REM (rapid eye movement) and NREM (non-rapid movement) - five stages
- eg. sleep cycle
- Evidence from Dement and kleitman who monitored sleep patterns of 6 pp in sleep lab - brainwave patterns recorded on EEG and caffeine and alcohol were controlled - REM activity was highly correlated with experience of dreaming
- - = sample size
- Evidence from Dement and kleitman who monitored sleep patterns of 6 pp in sleep lab - brainwave patterns recorded on EEG and caffeine and alcohol were controlled - REM activity was highly correlated with experience of dreaming
- eg. sleep cycle
- Endogenous pacemakers - internal mechanisms that govern biological rhythms - eg. circadian seep/wake cycle
- Exogenous zeitgebers - influence biological rhythms - environmental events that are responsible to resetting the body clock of an organism eg. light, exercise, meal times, social activities
- CIRCADIAN - 24 - hour eg. sleep/wake cycle and body temperature
- SIFFRE - absence of external cues significantly affect the circadian rhythm - when he retured for an underground cave where there was no light he believed the date to be a month earlier than it was - suggests that his 24hr sleep/wake cycle was increased by lack of external cues - making him think one day was loner than it was
- ASHOFF AND WEVER - WW2 bunker - 4 weeks - deprived of natural light - majority of pp displayed circadian rhythms between 24-25 hrs
- Practical application in shift work - diseases resulted from stress of adjusting different sleep patterns
- Practical application to drug treatments drug work better at different time of the day
- INFRADIAN - last longer than 24 hours - female menstrual cycle
- The Nervous System
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