biopsychology

Cerebrum

Conscious thought, voluntary movement, memories

Cerebellum

A large structure of the hindbrain that controls fine motor skills. Balance and coordination

Medulla oblongata

Part of the brainstem that controls vital life-sustaining functions such as heartbeat, breathing, blood pressure, and digestion.

Hypothalamus

A neural structure lying below the thalamus; it directs several maintenance activities (eating, drinking, body temperature), helps govern the endocrine system via the pituitary gland, and is linked to emotion and reward.

Somatic nervous system

Controls skeletal muscle and sensory organs, voluntary. Reflexes are an exception

Autonomic nervous system

Involuntary muscle control eg smooth and cardiac. Divided into parasympathetic and sympathetic divisions

parasympathetic nervous system

Rest and digest
Inhibit heart rate, constrict pupils etc. conserves energy

Sympathetic nervous system

Fight or flight, increases heart rate, dilates pupils etc

Axons vs Dendrites

Axons carry signals away from the body, dendrites towards

Sensory neurons

neurons that carry incoming information from the sensory receptors to the brain and spinal cord. Tell the brain about the internal and external environment (know how to identify)

Relay neurons

Carry messages from one part of the CNS to another. Connect motor and sensory (know how to identify)

Motor neurons

Carry signals from the CNS to organs and effectors (know how to identify)

Reflex arc

Nerve pathway making a fast automatic response, innate. We all have them and they dont have to be learned.

Saltatory conduction

Action potentials jump from node to node in the myelin sheath to increase the speed that impulses travel at. This allows for faster information processing and development of complex cognitive abilities.

Synaptic transmission process

1. Electrical impulses travel down presynaptic neurone axon
2. Vesicles containing neurotransmitters move towards presynaptic membrane
3. Vesicles fuse w membrane and release nrtnsmtrs into synaptic cleft
4. Ntrnsmtrs diffuse across synapse and bind to receptors on post synaptic membrane
5. Causes a change in the postsynaptic neurone which increases or decreases likelihood of an AP in the second neurone
6. Electrical impulse triggered and travels down the axon
7. Neurotransmitter recycled into presynaptic neurone.

excitatory potentials

make it more likely for the neuron to start an action potential (dopamine)

Inhibitory potentials

Make it less likely for a neuron to start an action potential (GABA)

Endocrine system

Collection of glands of an organism that secrete hormones directly into circulatory system to be carried towards a target organ. Eg pituitary gland (master gland)

Thyroid- Thyroxine

regulates metabolism

Adrenal medulla - adrenaline

fight or flight, raises heart rate etc, triggers blood vessels to redirect to major organs like the lungs and the heart.

Adrenal cortex - glucocorticoids

increase blood glucose for energy

Testes: Testosterone

affects development of sexual organs in males and secondary sexual characteristics

Ovaries (oestrogen)

Development of female sexual characteristics; aspects of pregnancy and foetal development

Pineal - melatonin

Regulation of arousal and biological rhythms (sleep wake cycle)

Fight or flight response

Stressful situation
Amygdala sends distress signal to hypothalamus
Hypothalamus activates the SAM pathway which runs to the adrenal medulla and sympathetic nervous system
The sympathetic NS stimulates the adrenal medulla and adrenaline and noradrenaline are secreted into the bloodstream
This triggers bodily ForF changes eg increase in heart rate and dilation of pupils

Fight or flight (A03) - tend and befriend (Taylor et al 2000)

Different between males and females
Taylor et al suggested that for women, responses to stress may be characterised by protecting themselves and their young through nurturing and forming protective alliances with other women (befriending). Could be due to oxytocin production in females, decreases stress response so women are less likely to "fight"
Women also dont have the SRY gene (Lee and Harley) which promotes aggression.

Fight or flight (A03) - positive rather then fof (Von Dawans et al)

Challenged the view that men respond w fof and women with tend and befriend
Found that acute stress can leas to greater cooperative behaviour, even in men. This is bc humans and fundamentally social animals and our protective nature has allowed our species to survive. Explains connection that humans have during times of crisis like terrorist attacks.

Fight or flight (A03) - negative consequences of fight or flight

The stressors of modern day life rarely require high levels of physical activity such as running away from a stressor. Problems arise when the stress response is repeatedly activated.
Eg increased blood pressure associated with SNS activation can lead to physical damage in blood vessels and lead to heart disease.

What is localisation of function in the brain?

The theory that different areas of the brain are responsible for different behaviours, processes or activities.

Brain hemispheres

Connected by corpus callosum
Activity of left side of body controlled by right hemisphere and vice versa
Brocas and Wernickes found on left side: it handles language functions
Right side: emotions,, face recognition, spatial comprehension

4 lobes of each hemisphere

frontal, parietal, temporal, occipital

Frontal lobe

Cognition, problem solving, motor skills, emotions, planning. At the front of the skull. Damage includes personality changes.

Back of the frontal lobe - motor area

Controls voluntary movement in the opposite side of the body. Damage \= loss of control over fine movements.

Parietal lobe

Sensation, perception and spatial reasoning. Processes sensory info., information processing. Damage \= issues with reading/writing/language. Right side damage may \= inability to dress etc, left side damage \= language disorders.

Front of parietal lobe - somatosensory area

Where sensory information from the skin is represented. Amount of ssa devoted to an area denotes its sensitivity.

Temporal lobe

Process auditory sounds, hearing. Form long term memories and interpret smells and sounds.

Temporal lobe - auditory area

Analyses speech based information. Damage \= hearing loss.

Occipital lobe

Back of the skull, vision and visuospatial processing, colour recognition. Damage\= vision problems.

Occipital lobe - visual area

Each eye sends info from their visual field to the corresponding visual cortex. It is processed.

Broca's area - Tan - left frontal lobe

Controls language production.
Tan could only produce that one syllable, but could comprehend spoken language and communicate with hand gestures. Had a lesion in Broca's area.
Damage \= Broca's Aphasia: slow speech, not grammatically correct, usually single words

Wernickes area - left temporal lobe

Language comprehension. Patients able to speak but unable to comprehend language. Damage \= Wernickes aphasia - production of nonsense words but can speak.

+ Localisation A03: Brain scan evidence - Peterson et al 1988

Wealth of evidence proving localisation of function, especially in relation to language and memory. Peterson et al used brain scans to demonstrate how Wernickes area was active during a listening task and Brocas area was active during a reading task, suggesting that these areas of the brain have different functions.

+ Localisation A03: Clive Wearing

Had a damaged hippocampus and had a short term memory and no long term memory, had procedural memory but not episodic. This suggests the memory stores are looked after by different parts of the brain.

+ Localisation A03: neurosurgical evidence

Surgically removing or destroying areas of the brain to control aspects of behaviour - Freeman's lobotomies to control aggressive behaviour.
Dougherty et al reported 44 OCD patients who'd undergone a cingulotomy, 1/3 met thr criteria for a successful response to the surgery. Success of procedures like this suggests symptoms and behaviours associated with serious mental disorders are localised.

- Localisation A03: neurosurgical evidence

2/3 of the Dougherty et al sample did not respond fully to the surgery which suggests that maybe there are surrounding/different areas that are also connected to the development of mental disorders.

+ Localisation A03: Phineas Gage

Metal pole went straight through his cheek and out of his left frontal lobe. The frontal lobe is said to control personality and behaviour factors, and his personality was said to have changed after the accident- he became vulgar and rude. Supports localisation.

- Localisation A03: Lashleys research

Removed areas of the cortex in rats that were learning a maze. No area was proven to be more important than any other area in terms of the Rats ability to learn the maze. The process of learning seemed to require every part of the cortex rather than being confined to a single area. Behaviour is too complex to be localised (HOWEVER: its rats so we cant really generalise)

- Localisation A03: plasticity

When the brain has become damaged, and a particular function has become compromised or lost, the rest of the brain is able to recognise itself in an attempt to recover the lost function. Documented case studies of stroke victims being able to recover abilities that were seemingly lost.

+ Localisation A03: further eval with Sarah Scott and Byron Peterson

SS - Brocas Aphasia - had a stroke and couldn't formulate coherent fluid speech
Byron Peterson - Wernickes Aphasia - had a stroke and could produce fluent language but he spoke in nonsense words and didn't understand what he was saying - had a lesion on the WA.

Hemispheric lateralisation

The idea that the two halves of the brain are functionally different and that certain mental processes and behaviours are mainly controlled by one hemisphere rather than the other.

Sperrys split brain research into HL 1968

Involved a group of individuals who had a commissurotomy - corpus callosum was cut down the middle to prevent seizures. Sperry devised an experiment to see to what extent the two hemispheres were specialised for certain functions.
Presented an image/word to the right visual sphere, and the same/different img/word presented to the left. In a normal brain the hemispheres would share the info to give a complete picture of the visual world.
Findings: when picture shown to right vf, patient could describe what was seen. If shown to left vf, couldn't describe what was seen. Inability to describe is due to the lack of language centres in the right hemisphere. Patients couldn't describe objects presented in the left vf, but they could suggest a matching object from a bag of different objects using their left hand (right hs). Couldn't describe the object but could understand what it was.
Conclusions: different areas of the brain specialise in different functions. LH converts sight into spoken and written language, RH can still produce a non verba response

+ Sperry A03: demonstrated lateralised brain functions

Pioneering work into split brain phenomenon, impressive and sizeable body of research findings, main conclusion of which appears to be that the left hemisphere is more geared towards analytic and verbal tasks, and the right towards spatial tasks. Paved the way for further advances. Influential.

+ Sperry A03: combined qualitative and quantitative approaches

Used a mixture of quasi experiments and clinical case studies. This combination allows for the collection of statistically reliable information to be enhanced by information about the research participants explanation. It makes up for validity lost by the experiment, and the experiment makes up for reliability lost by the case study.

- Sperry A03: small sample size + control group

Only had 11 participants, however Sperry may have not had any control over this as there may not be man split brain people to study. Small sample also allowed Sperry to gain more in-depth data. We also cannot be sure how long each of the patients had experienced ineffective drug therapy which could've been affecting the findings. The comparison group used by Sperry was also just people with no inter hemisphere disconnection, could be argued that a much more valid group would be epileptic people who hadn't had their hemispheres disconnected.

- Sperry A03: differences in function may be overstated

Sperrys work overemphasises and oversimplifies the functions between the L+R hemispheres. Modern neurosciences would argue that the distinction between hemisphere functioning is not as clear cut as Sperry suggests, in abnormal brai the hemispheres are in constant communication and many behaviours performed by one hemisphere can be performed by the other (plasticity), which challenges Sperrys work and emphasises complexity in brain function.

Brain plasticity

Existing neural connections can change and new ones can be formed as a result of new learning and experience (plasticity)

+ Maguire et al 2000 plasticity

Studied brains of london taxi drivers
More volume of grey matter in the posterior hippocampus than in a control group
This area of the brain is associated with the development of spatial/navigational skills.
London taxi drivers do tests of streets and possible routes.
As a result of this learning, their brain structure is altered.

+ Draganski et al 2006 plasticity

Imaged brains of medical students 3 months before and after their final exams and discovered earning induced changes to the hippocampus and parietal lobe. Shows brain can change over time as a result of choices.

+ Mechelli et al 2004 plasticity

Larger parietal cortex in the brains of people who were bilingual compared to monolingual controls.

+ Kuhn et al 2014 plasticity

Vide games increase grey matter in various parts of the brain including the hippocampus and cerebellum when comparing to a control group. This is believed to be because video games involve complex cognitive and motor actions which result in new synaptic connections in the brain areas responsible for spatial awareness and navigation.

+ Danielli et al 2013 plasticity + functional recovery

14 year old EB had a left hemispherectomy at 2 and a half, Brocas and Wernickes areas were removed. Lost all language ability. After 2y of recovery, he recovered language ability and developed normally as he aged despite some dyslexia like symptoms. This shows that the brain can adapt and recover, his right hemisphere took on the roles of his left hemisphere.

+ Gabby Giffords plasticity + functional recovery

Assassination attempt, shot in the head
Within months, abl to walk and control her left arm and leg. Could read and understand and speak in short phrases.

What happens in the brain during recovery

Forms new synaptic connections
Secondary neural pathways are "unmasked"/activated to enable functioning to continue
Axonal sprouting: growth of new nerve endings which connect wit other undamaged nerve cells to form new neuronal pathways
Reformation of blood vessels
Recruitment of similar areas on the opposite side of the brain to perform specific tasks.
Stem cells: differentiate into other types of cells for example functioning nerve cells.

Wall 1977 neuronal unmasking

Identified "Dormant synapses" within the brain - their functions are blocked and ineffective, neural input too low for activation. Damage to other areas causes these pathways to become "unmasked" and open the dormant synapses as new routed for neural input. Develops new structures which take over the functions oof damaged areas.

+ Plasticity and functional recovery A03: practical application to real life

Contributed to neurorehabilitation. We are now aware that spontaneous recovery after injury slows after some eels, so physical therapy may be required to maintain the improvements in functioning. Movement therapy and electrical stimulation of the brain may be experienced after a stroke. Although the brain can initially heal itself, therapy may be necessary for long term success.

- Plasticity and functional recovery A03: negative consequences of plasticity

Brains ability to rewire itself may have maladaptive behavioural consequences. Prolonged dug use has been shown to result in poorer cognitive functioning as well as increased risk of dementia. 60-80% develop phantom leg syndrome. This is thought to be due to cortical reorganisation in the somatosensory cortex.
Functional plasticity tends to reduce with age also.

+ Plasticity and functional recovery A03: research support from animal experiments (Kempermann et al, Hubel & Wiesel)

Kempermann et al 1988: studied rats to see whether enriched environments could alter neurons within the brain. When rats were in complex environments compared to a control group, they found that they had an increase in hippocampus neurons, associated with formation of new memories and navigation. This supports the view that life exeriences can cause brain plasticity.
Hubel & Wiesel 1963: sewed an eye of a kitten shit and analysed brains cortical responses. The area of the visual cortex associated with the shut eye was not as idle as expected and instead continued to process information from the open eye.

+ Plasticity and functional recovery A03: research support from human studies

Maguire et al + evidence in previous flashcards (Danielli + Gabby)

Ways of investigating the brain: fMRI + Shergill at al

3D scans that provide structural and functional information, detects changes in blood oxygenation and flow that occur as a result of neural activity. When a brain area is more active, it consumes more oxygen and to meet this demand blood flow is directed to that area.
Can be used to diagnose medical problems as they can show damaged or diseased areas of the brain.
Shergill et al 2001: showed which areas of the brain were active during hallucinations in a patient with schizophrenia.

Ways of investigating the brain: EEG

Shows overall electrical activity of the brain, picks up signals of firing neurons together, not individual neurons. Measure this via electrodes fixed to an individuals scalp. Recording represents brainwave patterns generated from neurons, a pattern of waves which represent different levels of consciousness and arousal. Often used to diagnose arrhythmic patterns of activity eg epilepsy.
Used in sleep studies and have been used to study depression and schizophrenia. Can be used as a diagnostic tool.

Ways of investigating the brain: ERPs

How EEG wave pattern changes in response to a stimulus. All extraneous activity from the EEG is filtered out leaving only responses to the presence of s stimulus or performance of a specific task. ERPs remain, types of brainwave triggered by particular events. Used in memory research.

Ways of investigating the brain: Post morgen examinations

Dissecting the brain of someone who has died. Physically look at the internal structure of the brain. Areas of damage are examined to establish likely cause of the affliction the person suffered. May include comparison with a neurotrophic al brain. Provided evidence for localisation of function in the brain.

A03: fMRI

+ doesnt rely on the use of radiation, it is virtually risk free, non invasive, straightforward.
Produces very high spatial resolution images, depicting lots of detail. Provides a clear picture of how brain activity is localised
- expensive, only captures a clear image if the person stays completely still. Poor temporal resolution. Can only measure blood flow in the brain, cannot focus on the activity of individual neurons, so it's difficult to tell what kind of brain activity is bring represented on screen.

A03: EEGs

+ contributed too the understanding of the stages involves in sleep. High temporal resolution, accurately detects brain activity.
- generalised nature of the information received- for the entire brain activity. Not useful for pinpointing the exact source of neural activity and does not allow researchers to distinguish between activities originating in different but adjacent locations.

A03: ERPs

+ beings more specificity to the measurement of neural processes, high temporal resolution, widespread use, allocation of attentional resources and the maintenance of working memory. Allows us to pinpoint different sources of brain activity.
- lack of standardisation. Methodology between studies makes it difficult to confirm any findings. In order to establish pure data with the ERP, background noise and extraneous variables must be completely eliminated which is not easy.

A03: Post Mortem Examinations

+ was vital in providing a foundation for early understanding of key processes in the brain. Broca + Wernicke relied on it to establish links between language, brain and behaviour. Improves medical knowledge and helps generalise a hypothesis for further study.
- causation is an issue as we cant be sure damage seen in the PM is linked directly to brain behaviour. PM studies raise ethical issues of consent from individuals before death. For example HM did not give consent but his postmortem was still carried out.

Biological rhythm

Patterns of changes in body activity over cyclical period. Influenced by internal body clocks (endogenous pacemakers) and external environmental changes (exogenous zeitgebers)

circadian rhythm

the biological clock; regular bodily rhythms that occur on a 24-hour cycle. Regulate a number of body processes like the sleep and wake cycle and changes in body temperature.

The sleep/wake cycle

Circadian rhythm
We feel drowsy at night and alert during the day, demonstrates effects of daylight (exogenous zeitgeber)

Circadian sleep/wake cycle: Siffre (+EP and EZ)

Spent two months in a cave to deprive himself of light and sound. Did the same for 6 months. Each time, his biological rhythm settled down to one that was beyond 24h (25h) though he continued to fall asleep and wake up on a regular schedule. (Supports EPs). Suggests natural sleep/wake cycle may be slightly longer than 25h but it is entrained by EZs within our day eg meal times and light. (EZ support)

Circadian sleep/wake cycle: Aschoff & Wever (+EP and EZ)

Group of ppts spent 4 weeks in a bunker deprived of natural light, all but one displayed a circadian rhythm between 24-25 hours. (EPs). Suggests natural sleep/wake cycle may be slightly longer than 25h but it is entrained by EZs within our day eg meal times and light. (EZ support)

Circadian sleep/wake cycle: Folkard et al (+EP -EZ)

Studied 12 people who agreed to live in a dark cave, going to bed when the clock said 11.45pm and rising when it said 7.45am. Over the course of the study the researchers sped up the clock (unbeknownst to the ppts) so a 24h day only lasted 22h. Not one of the ppts could adjust to it, this suggests a strong free running circadian rhythm that cannot be easily overridden by changes in the environment (EP support)

+ Circadian sleep/wake cycle A03: practical application to shift work (boivin et al)

Knowledge of circadian rhythms have given researchers a better understanding of the adverse consequences that can occur as a result of their disruption. Eg night workers engaged in shift work experience a period of reduced concentration around 6am (circadian trough), meaning mistakes and accidents are more likely (Boivin et al)

+ circadian sleep/wake cycle A03: practical application to drug treatments

Circadian rhythms coordinate a number of the body's basic processes like heart rate, digestion and hormone levels. This has an effect on how well drugs are absorbed and distributed by the body, research into CRs has shown there are peak times during the day/night when drugs are most effective, has led to development of guidelines to do with timing of drug dosing (Baraldo 2008)

- circadian sleep/wake cycle A03: use of case studies and small samples

Studies of the s/w cycle tend to involve small groups of participants, as in Aschoff and Wever, or individuals like Siffre. People involved may not be representative of the wider population, limits the extent to which meaningful generalisations can be made.

- circadian sleep/wake cycle A03: individual differences

Individual cycles can vary, in some cases from 13-65 hours (Czeisler et al). Some people also display a natural preference for going to bed early and rising early (larks) and some prefer to do the opposite (owls). There are also age differences in sleep/wake patterns.

Infradian rhythms

Take longer than 2h to complete, eg menstrual cycle and seasonal affective disorder

The menstrual cycle

Monthly changes in hormone levels which regulate ovulation. Tim between the first day of her period and the day before her next. Takes approximately 28 days to complete. Hormones include progesterone and oestrogen. Endogenous system.

Stern + McClintock influence of EZs on menstrual cycle

29 women with history of irregular period were interviewed, samples of pheromones gathered from 9 women at different stages of their cycles. On day 1, samples were applied to all 20 women, on day 2 given a sample from the second day of the cycle etc. 68% of women experienced changes to their cycle which brought them closer to whoever gave them the pheromones.

Seasonal affective disorder

Depressive disorder with a seasonal pattern of onset. Persistent low mood and lack of interest and activity. Lack of light in the morning means the brain secretes melatonin for longer. This is thought to have a knock on effect on the production of serotonin in the brain, a chemical linked to the onset of depression.

Ultradian rhythms

biological rhythms that occur more than once each day eg the stages of sleep

Stages of sleep

1 and 2: light sleep, person easily woken, brain waves become slower as sleep becomes deeper
3 and 4: very slow delta waves, deep sleep, hard to wake someone
5: body paralysed yet brain activity sleeps up, rapid eye movement, dreaming.

+/- Infradian and ultradian rhythm A03: evolutionary value/low validity

Research shows evolutionary value of IRs, it may have been advantageous for ancestor female to menstruate together and become pregnant around the same time so offspring could be cared for collectively, increasing their chances of surival.
However Schank 2004 questions the validity of this perspective as too many females cycling together within a social group would produce competition for the highest quality males, lowering the fitness of potential offspring. Therefore avoiding synchrony may be the best evolutionary strategy.

- Infradian and ultradian rhythm A03: Infradian study methodology

Many factors which may change a woman's menstrual cycle that could confound the research, for example diet or stress. Therefore any pattern of synchronisation may occur by chance. Research also involves small samples of women and relies on them self reporting the onset of their own sample, it may be inaccurate. Important aspects of synchronisation studies may therefore lack validity.

+ Infradian and ultradian rhythm A03: Dement & Kleitman evidence for sleep stages

Monitored sleep patterns of 9 ppts and found evidence for the stages of sleep, especially REM sleep, brain activity varied according to how vivid dreams were, ppts were woken during dreaming and had accurate recall of their dreams. Suggests rem sleep is a distinct past of the ultradian sleep cycle.

+/- Infradian and ultradian rhythm A03: SAD practical application

Effective treatment for SAD is phototherapy, light box stimulates strong light in the morning and evening to reset melatonin levels. Relieved symptoms in up to 60% of sufferers (Eastman). But the same study recorded a placebo effect of 30% using a sham negative ion generator. This cast doubt on the real value of phototherapy which may just be effective because of expectations.

+ Infradian and ultradian rhythm A03: Reinberg study

Young woman lived in a cave for 3months and her cycle lengthened to 24.6 hours, and her menstrual cycle shortened to 25.7 days. It took a year before her cycle returned to normal. Light levels can influence period cycle. Supported by Finland, where during its very long symmertime daylight hours, conception rates increase. This suggests the menstrual cycle is longer in those months, and that the menstrual cycle overall is affected by Exogenous zeitgebers.

Endogenous pacemakers and the sleep/wake cycle

Mechanisms within the body that regulate internal biological rhythms
Suprachiasmatic nucleus (SCN)- bundle of nerve cells in the hypothalamus, maintains circadian rhythms like she s/w cycle. Receives info about light which continues even when eyes are closed, enabling the biological clock to adjust to changing patterns of daylight. Passes info about the day length and light that it receives to the pineal gland which secretes melatonin.
+ DeCoursey at al - destroyed SCN connections in the brains of 30 chipmunks who were returned to their natural habitat and observed for 80 days, sleep/wake cycle disappeared and a lot of them were killed by predators because they were awake and vulnerable to attack when they should have been asleep.
+ Ralph et al bred mutant hamsters with a 20h sleep/wake cycle. When SCN cells from the foetal tissue of these hamsters were put into the brains of normal hamsters, their cycles changed to 20h. Emphasises the role of the SCN in maintaining circadian rhythms.

Exogenous zeitgebers and the sleep/wake cycle

Environmental cues which help regulate the biological clock, eg light.
Light resets the SCN and plays a role in the maintenance of sleep/wake cycle. It helps control hormone secretion and blood circulation.
+ Campbell & Murphy demonstrated that light may be detected in skin receptor sites on the body even when the same information is not received by the eyes. 15 ppts woken at various times and light was shone on the back of their knees, deviated sleep wake cycle by up to 3 hours. Suggests light is a powerful EZ.
Social cues are also EZs, schedules imposed by parents on babies like mealtimes and bedtimes. Local time zones is also a social cue, and we should live by those.

- EP and EZ A03: SCN research may obscure other body clocks

Body clocks are found in many organs and cells like lung and skin, highly influenced by SCN actions but can act independently. Damiola et al showed how feeding patterns in mice altered circadian rhythms of liver cells for up to 12h, leaving rhythm of the SCH unaffected. Suggests there are many other influences on the sleep/wake cycle, aside from the SCN.