Biopsychology Flashcards
What is the human nervous system?
Body wide system of nerve cells that collects information from the world, processes this info and then takes action by directing body organs and muscles via the transmission of electro chemical messages.
What is the central nervous system?
Involves complex processing. Includes the Brain for all conscious and most unconscious processing. And the spinal cord which receives and transmits information and some reflex processing.
What is the peripheral nervous system?
Body wide network of messenger neurones. Sensory neurones take info to the CNS, and motor neurone take information away from the CNS
What is the automatic nervous system?
The part of the PNS that controls actions of internal glands is a involuntary system (not under conscious control)
What is the somatic nervous system?
The part of the PNS that controls skeletal muscles. It is a voluntary system (under conscious control)
What is the Sympathetic system?
Part of the ANS. Increases bodily activities. Releases noradrenaline, activated in fight/flight response. Increased heart/sweat/breathing rate, dilates pupils.
What is the parasympathetic nervous system
Part of the ANS. Decreases bodily activities. Releases acetylcholine. Activated in rest. (Rest and digest) decreased heart/sweat/breathing rates, constricts pupils
What is homeostasis?
Our internal environment is regulated by a balance between the sympathetic and parasympathetic systems
What is the endocrine system?
Collection of glands around the body that regulate bodily functions, growth, and psychological factors. It acts by releasing chemical messengers called hormones into the blood
What does the pituitary gland do?
Master gland: hormone (ACTH), controls the release of hormones from other glands.
What does the hypothalamus do?
Hormone (CRH) links the nervous system to the endocrine system
What does the pineal gland do?
Hormone (Melatonin) modulates sleep pattern, keeping the body to a day/night rhythm
What does the thyroid gland do?
Hormone: (thyroxine) modulates metabolism (rate of energy use in the body)
What does the thymus gland do?
Hormone (thymosine) stimulates the development of T cells in the immune system
What does the pancreas do?
Hormone (insulin) regulates blood sugar levels
What do the adrenal glands do?
Hormone (adrenaline) Regulate the effects of the fight or flight response
What do the ovaries do?
(Female): hormone (oestrogen) develops secondary sexual characteristics in females
What do the testicles do?
(Male): hormone (testosterone) leads to the development of secondary sexual characteristics in males
Function of the sensory neurone?
Detect sensations at the sensory receptors. Action potential travels across the nerve passing along the myelinated axon then the electrical signal is converted into a chemical signal to cross the synapse
Function of the relay neurone?
After synaptic transmission, a new action potential forms in the dendrites, this neurone is in the spine, and sends a signal along its axon to the motor neurone
Function of the motor neurone?
Detects signal from the relay neurone via synaptic transmission and passes this signal along its own myelinated axon to stimulate an effector.
What is the synapse?
Also called axon terminal. This structure is found at the end of a nerve cell and allows neurones to communicate by passing on chemical signals this process is called synaptic transmission
What are neurotransmitters?
Chemical messengers released by neurones. These are either excitatory (stimulate/ make more likely) or inhibitory (male less likely) the development of an action potential (electric message) in other (post synaptic neurones)
What is the process of synaptic transmission?
The action potential travels down the axon of the presynaptic neurone. This forces vesicles containing neurotransmitters to merge with the cell membrane and release neurotransmitters into the synaptic cleft. Receptors on the postsynaptic neurones dendrite membrane detects the presence of neurotransmitters, changing the chemistry within the postsynaptic neurone. If the charge inside the post synaptic neurone passes a threshold a new action potential forms and the message is passed on. The neurotransmitters detach from the receptors and return to the presynaptic cell via transport proteins, this process is called reuptake.
What is excitation?
Excitatory neurotransmitters increase the likelihood of a new action potential forming in the post synaptic cell. When detected by receptors the electrical charge inside becomes more positive and likely to fire - depolarisation.
What is inhibition?
Inhibitory neurotransmitters decrease the likelihood of a new action potential forming in the post synaptic cell. When detected by receptors the electric charge inside becomes more negative and less likely to fire - hyperpolarisation
What is summation?
Combine effect of all inhibitory and excitatory influences, resulting in a new action potential forming or not forming.
What is uni direction?
Information can only be passed between pre and postsynaptic neurones in one direction. This is all due to the structure of the synapse such as the location of neurotransmitters and receptors.
What is fight or flight response?
An evolutionarily survival mechanism in response to a threat. It primes the body and mind for extreme action, such as fighting for out life of escaping a threat. The body returns to homeostasis after the threat has passed.
What is the process and mechanisms of fight or flight response?
A stressor is detected by the hypothalamus. The HPA axis in the endocrine system is activated, and the pituitary gland released ACTH; this is detected by the adrenal cortex, releasing cortisol. The hypothalamus also activated the sympathetic branch of the ANS, and the adrenal medulla is triggered via the sympathetic adrenomedullary pathway, releasing adrenaline.
What is the role of adrenaline?
Psychological effects of adrenaline include increased anxiety, attention and alertness. The physical effects of adrenaline include increased blood flow to the brain and skeletal muscles (quick thinking/reactions) and decreased blood flow to the skin and the digestive immune systems. Dilated pupils (improved vision) and faster breathing rate (increased oxygen)
Why is the fight or flight response maladaptive in the modern world?
It is frequently triggered by stimuli that cannot be run away from or fought (e.g. exams). In the short term, this results in acute stress, a response to immediate pressures, exciting in small amounts and giving you focus and energy but exhaustive if maintained. Long term frequent triggering of the fight or flight response results in chronic stress, which can result in stress related illness affecting the immune and circulatory systems.
What is localisation of function?
Functions such as movement, speech/language and memory are performed in distinct regions of the brain. The opposite view is the brain acts holistically to perform functions
What is contralateral?
Each hemisphere controls the opposite side of the body. Including both motor and sensory pathways and vision of the contralateral visual field.
What is hemispheric lateralisation?
Each hemisphere is specialised to perform different functions. (Language centres are in the left hemisphere, visuospatial tasks are best performed by the right)
What is the function of the motor cortex?
Voluntary muscle movement across the body. Contralateral. At the back of the frontal lobe and separated from the somatosensory cortex by a fold called the central sulcus. Damage: injuring results in the loss of muscle function or after severe trauma, paralysis on the opposite side of the body.
What is the function of the somatosensory cortex?
Receiving sense impressions from around the body. Contralateral. Front of the parietal lobe and separated from the motor cortex by a fold called the central sulcus. Damage: loss of sensation in opposite side in damage, ignoring areas of the body.
What is the function of Broca’s area?
Located in the left frontal lobe only, Broca’s area is responsible for speech production. Damage: motor aphasia/ difficulty producing fluent speech
What is the function of Wernickes area?
Located in the left temporal lobe only, responsible for speech comprehension. Damage: sensory aphasia/ difficulty understanding speech
Function of the auditory cortex?
Receives and processes sound information from ears. Located in both hemispheres
Function of the visual cortex?
(Occipital lobe) visual processing each hemisphere receives info from opposite visual field.
How do case study research support brain localisation?
Clinical case study research demonstrates loss of certain functions if damage is caused to particular areas of the brain e.g. Broca and wernicke’s case studies (aphasia) and Clive wearing (amnesia). This suggests these functions (language/memory recollection) are localised and located in these areas damaged.
Why are case studies not good evidence for brain localisation?
The use of case studies is seen as unscientific, especially in brain research with damage often covering multiple regions, as seen when modern MRI scans were made of Tans brain
How do brain scanning techniques support brain localisation?
Modern brain scanning techniques like fMRI support older research on language centres, showing activation in the regions previously associated when healthy participants perform language tasks.
What is a positive and a negative for brain localisation
Motor and somatosensory functions are highly localised, however systems like language are more distributed and some functions like consciousness appear not to be localised at all. This suggests the correct approach for the localised of holistic nature of the brain is dependent on the function. Also due to high connectivity of the brain, no one area is truly independent.
What is corpus callosotomy?
A surgical procedure for epilepsy. Cutting the corpus callosum which isolates each hemisphere from the other. Reduces epileptic symptoms and has few side effects for such an invasive procedure.
What was sperrys (1968) split brain research?
Quasi experiment using 11 patients who had all undergone corpus callosotomy. Sperry projected information to each visual field, so controlling the information that each hemisphere had access to. In a series of tests participants would be required to say what they had seen, draw objects or select from a number of objects that were hidden from view with their hands. Found, information presented to the left hemisphere could be spoken, but not spoken if delivered to the right hemisphere. However, the right hemisphere could draw or select the object by using the left hand. Suggesting the hemispheres are both capable of acting independently (memories and awareness) also supporting the theory that language centres are in the left side of the brain.
What was gazzanigas (1983) split brain research?
Split Brian research also using patients who had undergone corpus callosotomy found that when each hemisphere of split brain patients were presented with faces the right hemisphere was much more able to recognise them. Suggesting that the right hemisphere was specialised for facial recognition.
What was wrong with the participants used by sperry?
The sample of split brain patients in the studies are small, participants were compared against non-epileptics, had varying amounts of connection cut and all undergone drug therapy. The control group used by spotty also were healthy with no history to fits. This suggests some of the result may have been due to participant variables making the results ungeneralisable to the wider population.
What is wrong with the validity of the studies on split brain research?
Experimental procedure used is unlike how these individuals would process information and act in normal day to day life (tasks lack mundane realism). In reality these people led mostly normal lives, moving their head from side to side and using other cues to pass on information to both hemispheres resulting in low external validity.
Positive of split brain research
Research has had a fundamental impact on the psychological and philosophical understanding of both the unity of consciousness and identity. Suggesting that the brain is a combination of separate intelligent processes working together.
What is plasticity?
The brain adapts in both its function and structure as a result of change in the environment. These changes could be due to damage or to meet cognitive demands of learning new skills
Four reasons for plasticity are: learning new skills, result of developmental changes, response to direct trauma to area of the brain, response to indirect effects of damage such as brain swelling or bleeding
What is functional recovery?
The functions that were performed by areas of the brain that are lost or damaged are performed by undamaged areas of the brain. - functional reorganisation
What is synaptic pruning?
Synapses that are used frequently become stronger over time, however unused synaptic connections are lost. This makes the brain a more efficient communication system over time.
Axonal sprouting?
When existing neurones grow new axons to connect to adjacent neurons. Neural regeneration is the growth of new neuronal cells.
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What is Denervation super sensitivity?
To compensate for the loss of axons in a pathway the remaining axons become more sensitive. (More likely to fire. This can result in side effects such as pain.
Factors affecting functional recover?
Age: children have the best ability to recover, then young adults. Gender: women are more able to recover from brain damage. Access to rehabilitative therapy: focused effort results in improvement. Constrained induced therapy is stopping patients form using coping strategies.
How does maguires study sport brain plasticity?
Maguire (2000) MRI of 16 male taxi drivers were compared to MRI ago 16 matched (age, gender) non taxi driver controls. The posterior hippocampi in the London taxi drivers were found to be significantly larger than the controls. Suggesting the physical structure of the brain is plastic, able to reconfigure itself to better adapt to psychological demands.
How does danelli’s (2013) case support brain plasticity?
Case study of 14 year old EB. At 2 EB had a hemispherectomy of the left side of his brain to remove a tumour. This removed the language centres of Broca’s and Wernicks areas. Immediately after surgery EB had lost all language ability. However after two years of recover EB had recovered his language ability.
Practical benefits of plasticity research?
Research on brain plasticity and functional recovery had practical benefits. It has been useful in rehabilitative therapy e.g. constraint induced therapy, stopping patients using coping strategies makes them improve via functional reorganisation. Helping people return to their lives and being productive, ultimately benefiting the wider economy.
Support for brain plasticity?
Research on individuals recovering lost function can help psychologists understand more about the functions and regions of the brain that were initially damaged.
What was Mathias (2015) meta analysis?
Meta analysis demonstrated not everyone has high levels of plasticity, finding IQ and education background are positively correlated with better outcomes after traumatic brain injury, suggesting some individuals have a greater cognitive reserve, helping in recovery and some people will struggle to regain function.
What is functional magnetic resonance imaging?(fMRI)
Detects blood flow in the brain. As more active areas of the brain need more blood, these active areas can be compared to low activation areas with a lower blood supply and displayed on an FMRI image.
Positive of fMRI?
Good spatial resolution of 1mm. Precisely identifying brain regions and patterns of activation over time while participants complete experimental conditions.
Negative of fMRI?
Poor temporal resolution as one image is taken every few seconds and dealt in blood flow after activity. Many brain processes are too fast to study.
fMRI are expensive to build and operate. Also the participants need to be still, body movements are not possible.
What is and electroencephalogram (EEG)?
EEG is a collection between 22-34 electrodes that are attached to a cap, and fitted careful,y to the scalp with conductive gel. The read out from each electrode is the sum total of activation of the brain cortex under the electrode. This is displayed as a series of lines showing distinct patterns called brain waves. The amplitude show wave intensity and frequency show the speed of activation.
Positives for EEG?
historically important in understanding brain activity in areas such as sleep research and medical diagnosis.
Cheaper than alternatives such as fMRI a and able to be used in experiments in which the participants move
Very good temporal accuracy, measuring brain activity with a resolution measure in milliseconds
Negative of EEG?
poor spatial activity as pattern is a large number of neurons in the cortex under the electrode. Also cannot detect activity deep within the brain.
What is an event related potential (ERP)?
Use the same technique as EEG but present the stimulus many times, creating a smooth curve of activation by combining data in a process called statistical averaging. This removes background noise unrelated to the stimulus. The waveforms peaks and dope show exactly when cognitive processes in the brain happen after the stimulus is prepared.
Positive for ERP?
Allow researchers to isolate and study how cognitive processes take place in the brain whilst EEGS record general brain activity
Good temporal resolution with millisecond sampling rate
Negative of ERP?
Very poor spatial resolution, some techniques cannot be studied due to not being able to present the stimulus many times.
What are post-mortem examinations?
Brains are precisely cut after treatment to give a firmer texture. Unusual brains are dissected such as brains that suffered trauma, or from individuals that suffer from mental illness. These brains are compared with neurotypical brains. Broca’s area, responsible for language production was discovered using post mortem on a patient called Tan, who could only say Tan. Damage to an area of the frontal lobe was found after Tans death.
Positive of post mortem examination?
High spatial resolution, microscopic studies down to the neuronal level
Theories tested can be compared with other techniques
Negatives of post mortem?
Anything found is a correlation as it’s not conducted on a living brain
What is a circadian rhythm?
Biological rhythm that lasts 24 hours. We have a circadian rhythm for regulating sleep and wake, the release of hormones, and varying our body temperature and blood pressure.
What are endogenous pacemakers?
Internal body clocks that keep our biological processes to time
What are exogenous zeitgebers.
External cues that entrain internal body clocks to match the environment
What is the sleep wake cycle?
Pattern of sleep and wakefulness that repeats every 24 hours. Conflicts between EP and EZ like light and social cues in situations such as jet lag. EP will be entrained by the EZs to the new time zone but it can take several days.
What is the suprachiasmatic nucleus (SCN)?
EP for the sleep wake cycle, known as the master clock. The SCN is part of the hypothalamus within the limbic system. It’s located at the optic chiasm, the point on the optic nerves where they cross. When light is detected by the SCN it sends a signal to the pineal gland, stopping the production of melatonin, a hormone that results in a sleep response
What was Siffres case study?
Lived in a cave for 179 days. The cave had no natural light or other potential EZs such as clocks or social cues. Siffres body clock maintained a regular cycle of around 25 hours without EZs, longer than the expected 24 hour cycle. Suggesting the EP for the sleep wake cycle is free running but needs entrainment to keep the 24 hour cycle.
Negative for using artificial light in isolation experiments?
Artificial lights disrupt the free-running circadian rhythm measurement by acting as an EZ. Other studies that controlled for artificial light found the circadian rhythm was closer to 24 hours, with little drift.
What was Vetters study?
Found 27 office workers who were exposed to strong blue light shifted the timing to their circadian rhythms to match the office lighting. this suggests artificial light is a strong EZ for the sleep wake cycle.
What was Ralph’s study?
Surgically transplanted SCN between ordinary hamsters and hamsters with Tau mutation (20 hour CR). Found hamsters sleep wake circadian rhythm shifted to match the new SCN suggesting the SCN is the EP in sleep wake cycle.
Positive of CR research?
Practical applications, from understanding how blue light from devices disrupt sleep, how to combat the adverse effects of jet lag and shift work, and understanding the circadian blood pressure rhythms helps with timing drug treatments
What is an infradian rhythm?
Biological rhythm that takes longer than 24 hours to complete the cycle
E.g. SAD disorder (seasonal affective disorder). Emotional moods lower in winter and improve in summer
Process of the menstrual cycle?
28 day cycle with 6 days fertility, however, cycles can be shorter or longer, ranging from between 24-35 days. Biological aspects of this cycle include releasing the egg (ovulation), thickening of the womb lining and losing the womb lining during menstruation. These biological changes are regulated by the hormones oestrogen pre ovulation and progesterone post ovulation. The levels of these hormones act as endogenous pacemakers keeping the biological processes to time, acting as an internal body clock for the menstrual cycle.
What was McClintocks study?
Found 135 women who lived in the same dormitory at university appeared to synthesise their cycles with their friendships groups. This suggests the menstrual cycle infradian rhythm synchronises.
What was Stern and McClintocks study?
20 women were given pads taken from the armpits of donor women on their top lip each day. It was found that the women could shorten or extend their menstrual cycle to match the donor. This suggests infradian rhythm synchronisation due to the presence of pheromones, acting as EZ
Negative of pheromones?
Scientists are not sure we are able to detect the pheromones despite it being common in animals.
What did trevathan find?
Cohabitating lesbian couples did not synchronise, the optimal conditions for possible synchronisation, countering McClintocks theory.c
Negative of menstrual cycle studies?
They can vary in length, could just be the variability of the cycles which is something not taken into consideration in the studies showing positive results.
What is the evolutionarily conflict?
Some argue synchronisation is advantageous, stopping one male impregnating all the women at once, leading to genetic diversity in humans. Or maladaptive if they synchronised not all women could be fertilised by the male with the best genes, needing to compete with other women for him.
What is Ultradian rhythm?
Biological rhythm that takes less than 24 hours to complete one cycle.
What are the stages of sleep?
1-3 are non REM or NREM termed n1 n2 n3. After passing back through n2 n1, stage 4 is REM. One cycle take 90 minutes to complete and repeats 4-5 times over the course of one nights sleep.
What are the brainwaves?
Measured by EEG: delta, theta, alpha, beta, gamma. Vary by frequency and amplitude.
Outline Sleep stages
N1 - easy to wake up and sudden body movements. Sensation of falling and hypnagogic hallucinations
N2 - harder to wake, body is relaxed, heart rate and body temp lowered, still eyes.
N3 - deepest sleep, difficult to wake, most relaxed state, heart rate lowered.
From n1 to n3 less easily woken, slowing of brain wave frequency and increased amplitude.
Outline REM?
Similar to wakefulness however body is paralysed
Rapid eye movement and associated with dreaming
Dermot and kleitman?
Used eeg to record the brain activity of 33 participants during one nights sleep. Brain waves followed a cyclic activation pattern, with bodily relaxation during slow-wave sleep and rapid eye movement during periods of high activation. This supports the theory that stages of sleep are an ultradian rhythm with distinct features at each stage.
What was Shaprio’s study?
Ultramarathon runners showed longer sleep after intense physical activity. Also, an increased proportion of slow wave sleep supports the theory SWS is for the body’s physical recovery.
Haiders study?
EEGs of 10 patients recovering from drug overdose showed increased rem sleep, suggesting REM is mental recovery
Negative of individuals differences in sleep stages?
Newborn babies spending 80% of sleep in rem compared to 20-25% in adults. Suggests state of sleep is not a process but adapts to the developmental needs of the individual.
Czeisler found?
Longest period of REM sleep coincides with the lowest point in the circadian body temperature cycle. This suggests that circadian and ultradian rhythms are connected and perhaps shouldn’t be considered separate processes; both processes could use the same internal body clock (EP) the suprachiasmatic nucleus
Positives of ultradian rhythm research?
Practical applications; technology and devices based on understanding sleep stages have been developed. Track sleep and help individuals improve sleep. Avoid waking in stage 4 stops people from feeling disorientated. Leads to happier, healthier, more economically productive populations.
