Biopsychology Flashcards
What is the nervous system?
Specialist network of cells in the human body, collects and responds to information and coordinates organs and cells in the body
What is the Central nervous system?
Consists of the brain and spinal cord, is the origin of all complex commands and decision. Spinal cord is responsible for reflex actions
What is the Peripheral nervous system? + the 2 divisions?
Transmits messages via neurons to and from the CNS.
-Autonomic: Works vital functions in the body (heart rate, digestion)
-Somatic: Works muscle movement and receives information from sensory receptors.
What are the 2 divisions of the Autonomic system?
-Sympathetic: prepares the body for physical activity when the hypothalamus detects a stimuli, triggered when the body is in an ‘alert’ state. adrenaline is released to fuel activity, as well as physiological changes (increased heart rate, fight or flight response)
-Parasympathetic: Returns the body to usual state and preserves energy, enables ‘recovery’ mode (rest & digest)
What are neurons?
Provide the nervous system with the ability to communicate
Sensory Neurons
Carry messages from the PNS-CNS, have long dendrites and short axon, located outside of the CNS in the PNS in clusters called Ganglia.
Relay Neurons
Connect sensory and motor neurons, short dendrites + axon, 97% of all neurons, most found within the brain and visual system
Motor neurons
Connect the CNS to effectors (muscles + glands), short dendrites and long axon, cell bodies may be in CNS, long axons may form in the PNS
What is synaptic transmission?
Neurons communicate within neural networks, signals within neurons are electrically transmitted, when electrical signal reaches the Presynaptic terminal, neurotransmitters are released.
What are neurotransmitters?
Chemicals that diffuse across the synapse, taken up by dendrites of the next neurons postsynaptic receptor, signal is converted back to electrical. Each neurotransmitter has a specific molecular structure
Ach- found where a motor neuron meets a muscle, makes muscles contract
What is Excitation?
Increases the postsynaptic receptors positive charge, making it more likely to fire.
Adrenaline: stimulates action potential
What is Inhibition?
Increases the neurons negative charge, less likely to fire.
Serotonin: inhibits action potential
What is Summation?
The process of whether a postsynaptic neuron will fire or not
What is Action Potential?
Only triggers the neuron if the excitation or inhibition limit is reached
What is the Endocrine system?
instructs glands to release hormones directly into the bloodstream (chemical)
What are Glands and Hormones?
Gland: An organ that synthesises substances
Hormones: Biochemical substance that only affects target organs.
Glands produce hormones, hormones are secreted and affect and cells that have that specific hormones receptor
What hormones do the Pituitary, Thyroid, Pancreas, Adrenal Medulla control?
Pituitary: is in the hypothalamus, controls all other glands
Thyroid: thyroxine, increases heart rate, increases metabolic rates
Pancreas: produces insulin
Adrenal medulla: releases adrenaline
What is the Fight or Flight response?
-A threat is perceived, the hypothalamus activates the Pituitary gland and triggers the sympathetic state
-Adrenal Medulla releases adrenaline into the bloodstream
-Adrenaline then triggers the sympathetic state and physiological changes in the body; increased heart rate, inhibited digestion
-After the threat has passed, the parasympathetic state returns the body to resting state (rest+ digest)
What is a fMRI?
-Detects changes in oxygenated blood flow in the brain. An active area will consume more oxygen.
-Uses large magnets to produce a 3D image
-More active area= brighter colour image
fMRI evaluation:
+ High spatial resolution, allows an insight into how the brain works
+ Non-invasive and doesn’t use radiation, not harmful, ethical validity
-Low temporal resolution, 5 second delay, may mi9ss some information
What is an EEG?
-Places electrodes onto the scalp to record brain activity (skull cap)
-Electrodes measure activity of the cells below them, more electrodes= more detail
-Shows brain waves
-Used to diagnose sleep issues and seizures
EEG Evaluation
+Useful to study sleep patterns, sleep stages and epilepsy, real-world application
+High resolution, a millisecond
-Generalised activity of all neurons, not useful to source where activity originated
What is an ERP?
-uses the same technique as EEG, records when there is activity in a response to a stimulus
-Filters EEG data using a statistical averaging technique, the waves show when a cognitive process occurs (attention and perception)
ERP Evaluation
+cheaper than fMRI’s, allows easier epilepsy diagnosis
+High temporal resolution, accurate measurements of electrical activity when a task is performed
-Lack of standardisation between different studies, difficult to confirm findings, extraneous variables
What are Post-Mortem examinations?
-Used to determine cause of behaviours during their lifetime
-investigates brain structure, infers correlations between brain + behaviours
-Alzheimer’s is determines by PME
Brain is sliced and analysed
Post-Mortem evaluation
+Alzheimer’s diagnosis, conclusively confirms the disease, real-life usage
+Harmless to a living person, as long as consent is given
-Hard to gain full consent, limits ethics
What is a circadian rhythm?
A biological rhythm that occurs over a 24 hour cycle, if disrupted can increase risk of dementia, diabetes, depression
Describe the sleep/wake cycle
The SCN (suprachiasmatic nuclei) is found in the hypothalamus, it detects changes in light present. It controls the release of hormones (melatonin is released when less light is detected).
Describe Siffre’s study (1962)
-Spent 6 months in a cave, deprived of natural light and sounds, to study the effect on his biological rhythms
-RESULTS: Hid sleep/wake cycle remained regular
CONCL: Our biological rhythm of 24 hours is free-running.
Evaluate Siffre’s study
+ Practical application to shift work, it desynchronises circadian rhythms which has economic implications (sick pay)
- Case study evidence, results cannot be generalised as well as a lack of control over factors such as artificial light, lack of validity
What is an infradian rhythm? and an example
Biological rhythm that occurs less than once in 24 hours, menstrual cycle
Explain the menstrual cycle (infradian)
-28 day cycle
-Oestrogen levels increase causing an egg to release from the ovaries - Ovulation
-Progesterone increases, thickens the womb lining
Describe Stern + McClintock’s study (1998) and Evaluate
A- To see whether menstrual cycles synchronise as a result of the influence of pheromones
M- 29 women with irregular periods, rubbed a cotton pad on their upper lip, this cotton pad had previously been placed in another woman’s armpit
R- 68% of women’s cycles changed, closer to the pheromone donor
C- Pheromones can synchronise women’s menstrual cycles
+ Synchrony research can be explained by natural selection. Babies who lost mothers could have breast milk from other synchronised mothers, which improves survival
- Synchrony research could have many confounding variables, flawed studies, lack replication
What is Seasonal Affective Disorder (SAD)?
(infradian)
Winter days (darker and longer) result in more melatonin being released, leading to lower mood and higher risk of depression, and less serotonin is released
+ Can be treated with light therapy, real-world application
What is an Ultradian rhythm? + example
Biological rhythms that occur more than once in 24 hours, stages of sleep
Stages of sleep:
1+2: Sleep escalator: ‘light sleep’, slow alpha waves.
Sleep spindles: short bursts of brain activity, common in Stage 2
3+4: Deep sleep: Delta waves, slow and deep with greater amplitude
5: REM sleep: Rapid-eye movement, indicates dreaming is taking place. Brain activity speed up, CNS is cut off when dreams occur.
-75% of sleep time is stages 1-4 (NREM)
-Brain waves are monitored by an EEG
Evaluate the stages of sleep
+ Improved understanding of age-related sleep changes, Elderly lack SWS (slow wave sleep) resulting in a sleep-deficit. To increase SWS, meditation and relaxion is necessary. Ultradian rhythms have practical value
- Significant variation between people, Tucker found large differences within stages 3+4, biologically determined. Meaning it is difficult to describe ‘normal sleep’
+ Used laboratory studies, high control over extraneous variables
- However, sleeping in a lab is artificial and results would not reflect ordinary sleep patterns.
What are Endogenous pacemakers? and how to they impact the sleep/wake cycle?
-Internal mechanisms which determine our biological rhythms (body clocks)
-SCN: induces sleep, sends signals to pineal gland, then produces melatonin
-Peripheral oscillators: Other Endogenous pacemakers located outside of the SCN (lungs, pancreas)
Animal studies: DeCoursey et al
- destroyed 30 chipmunks SCN connections, then returned them to their natural habitat. Observed them for 80 days, they were attacked as they were active when they should have been asleep.
shows the influence of the SCN
Animal studies: Ralph et al
Bred mutant hamsters, who had a 20 hour sleep/wake cycle. SCN cells from these mutant hamsters, were put into normal hamsters. The cycle adjusted to 20 hours instead of 24 hours.
What are Exogenous Zeitgebers? and how to they impact the sleep/wake cycle?
-External factors that affect our biological rhythms.
-Light: can reset the SCN, affects our hormone secretion and blood circulation
Campbell + Murphy: Shone a light pad onto back of knee when ppt asleep, this affected the sleep cycle by 3 hours
- Maintains the sleep/wake cycle
-Social cues: Schedules, that we respond to which can affect rhythms
Evaluate Endogenous Pacemakers
- Research may obscure other peripheral oscillators, Damiola: change in feeding patterns, affected the liver by up to 12 hours.
-They cannot be studied in isolation, pacemakers and zeitgebers interact in everyday life, so it makes little sense to try and separate them, leads to a lack of validity.
Evaluate Exogenous Zeitgebers
-They do not have the same effect in all environments, light has no effect in the Arctic Circle, suggests their is no external effect on the sleep/wake cycle
- Evidence challenging Exo Zeitgebers, Miles: study of a man (who has been blind since birth) who has an abnormal circadian rhythm of 24.9 hours, despite exposure to social cues. Social cues have no effect in resetting biological rhythms.
+ Hood: Elderly insomnia reduced if they became more active and exposed to more natural light.
What is localisation of function?
The theory that different areas of the brain are responsible for specific behaviours, processes or activities
What is in the Frontal Lobe?
-Motor area: controls movement
-Prefrontal cortex: executive functioning (planning, controlling impulses)
-Broca’s area: speech production
What is in the Temporal lobe?
-Auditory area: auditorial processing
-Hippocampus: memory and spatial navigation
-Wernicke’s area: language comprehension
What is in the Parietal lobe?
-Somatosensory area: responsible for touch sensation
-Governs body orientation
-Aids learning of complex precise movements (writing)
What is in the Occipital lobe?
-Visual area: Process visual information, helps with depth perception, aids recognition of objects and faces
What is the 1.Cerebellum, 2.Brain stem, 3.Sentral sulcus?
- Controls balance and coordination
- Controls involuntary responses (reflexes)
- Separates the motor and somatosensory areas
What is Broca’s area?
-Left frontal lobe, responsible for speech production
-Damage: Broca’s aphasia; slow speech which lacks fluency
-Patient TAN; damaged Broca’s area could only say tan
What is Wernicke’s area?
-Left Temporal lobe, responsible for language comprehension
-Damage: Wernicke’s aphasia; produce fluent but meaningless speech
Who is patient HM?
-Amnesia
-Epilepsy patient who had his hippocampus removed.
-Now can’t form new memories (LTM damaged)
-supports localisation
Evaluate Localisation -Strengths
+Damage to areas of the brain has been linked to mental disorders, Cingulotomy isolates the cingulate gyrus, which has links to OCD. Dougherty analysed 44 people with OCD who had a cingulotomy. After 32 weeks, 30% had a positive response. Success shows mental disorders to be localised
+ Petersen used brain scans to show Wernicke’s area to be active when performing a listening task, Broca’s when reading. Confirms localisation in everyday life (objective method)
+Phineas Gage; linked personality changes, to the frontal lobe (damage changed his personality)
Evaluate Localisation- Weaknesses
-Lashley; removed areas of the cortex, in mice, they had to learn a route, no area proved more significant than others, holistic view
-Dick + Tremblay; only 2% of researchers believe language is limited to only Broca and Wernicke area’s, fMRI’s have shown language streams throughout the brain, language may be more holistic
-Case study evidence (Gage), results can’t be generalised to society, subjective, lack causality
What is Hemispheric Lateralisation?
One hemisphere of the brain performing a particular function.
What happens in the left hemisphere?
-Language area’s
-Analyses language
What happens in the right hemisphere?
-Synthesizes language
How is vision lateralised?
-Each hemisphere receives information form both eyes (contralateral + ipsilateral wiring).
-Right hem. controls the left side of the body
-Left hem. controls the right side of the body
-Loss of vision in one eye results in a lack of depth perception (2D vision)
Evaluate Hemispheric Lateralisation
+Fink; used PET scans to identify which area’s are active during a visual task:
Right; more active when looking at the bigger picture. Left; more active when looking for finer details.
-Research suggests that there isn’t a dominant sides which create personality. Neilson; analysed 1000 brain scans (age7-29), showed lateralisation but no dominant side
What is Spit-brain research?
-Corpus collosum removed, stopping the 2 hemispheres communicating
-For epilepsy patients to reduce symptoms
Describe Sperry(1968)
A- To investigate how the 2 separated hemispheres work (speech + vision)
M-11 patients, who had the operation, were studied. an image was shown to either the left or right visual field
R- Right field: ppt could describe what was seen (processed in the left hemisphere)
Left field: ppt couldn’t describe what was seen (use language), they could use their left hand to draw or select similar objects and showed an emotional reaction
C- Certain functions are lateralised
LH=verbal
RH= silent but emotional
Evaluate Sperry
+Gazzaniga~: found split-bran patients to be better at some tasks that normal brains (odd one out), supports distinct hemispheres
- Epilepsy is a confounding variable, relationship hard to establish, the split-brain may not be what caused the results
-Ethics: repeated testing may cause stress.
What is brain plasticity?
The brain’s tendency to adapt and change as a result of experience and new learning, growth of new connections
What is synaptic pruning?
Rarely-used connections are deleted, frequently-used ones are strengthened
Infants: 15,000 connections per neuron
Adults: 7,000 per neuron
What was Maguire’s study?
-Studied London taxi drivers brains
-More grey matter found in the posterior hippocampus than the control group
-The posterior hippocampus is linked to navigation and spatial skills
-Shows how learning alters brain structure
What was Draganski’s study?
-Analysed medical students brain scans, 3 months before and after exams
-Changes in posterior hippocampus + parietal cortex, presumably due to learning.
Evaluate Brain plasticity
-May have negative consequences, drug use has caused poor cognitive functioning and increased dementia risk. 60-80% of amputees develop ‘phantom limb’ syndrome, as they believe their limb is still there. Brain plasticity may not always be positive
+ Life-long ability, Bezzola: Showed how 40hours of golf training produced changes in neural representations of movement (ppts aged 40-60), shows neural plasticity can continue throughout our lifespan.
What is functional recovery?
The brain’s ability to redistribute functions performed by damaged areas to undamaged areas
Doige’s theory
The brain forms new synaptic connections close to the area of damage. New connections enable functioning to continue.
Doidge: Axonal Sprouting
Growth of new nerve ending which connect with other undamaged cells, to form new neuronal pathways - a diversion
Doidge: Denervation Super-sensitivity
Axons with similar functions become aroused to a higher capacity to compensate for the damaged ones, this can cause oversensitivity - strengthen supporting networks
Doidge: Recruitment of homologous areas
Areas on the opposite side of the brain, perform the same function but on the other hemisphere using existing pathways.
Evaluate Functional Recovery
+ Real-world application, stroke patients use neuro-rehabitation, to try to use damaged area, by restraining the undamaged area. Helpful in the medical field
-Schneider: revealed that the more time that people with a brain injury had education, had a greater chance of fully recovering. Brain damage patients who have insufficient education into recovery are less likely to recover.
