Biopsychology Flashcards
Nervous system structure
-Nervous system split into CNS (central nervous system) and PNS (peripheral nervous system)
-CNS split into brain and spinal cord
-PNS split into somatic nervous system and autonomic nervous system
-Autonomic nervous system is further split into sympathetic and parasympathetic nervous systems
What is the role of the somatic nervous system?
The somatic nervous systemm facilitates communication between between CNS and real-life movements + muscle movements
What is the role of the autonomic nervous system?
The autonomic nervous system is responsible for homeostasis and consists of only motor pathways
4 main lobes that the brain consists of
The 4 main lobes that the brain consists of:
-Ocipital lobe (processes visual info)
-Perietal lobe (spatial navigation)
-Frontal lobe (logic, reasoning)
-Temporal lobe (processes auditory info)
What is the role of the sympathetic nervous system?
The sympathetic nervous system is involved in the responses that prepare the body for fight or flight responses (increasing/decreasing functions)
What is the role of the parasympathetic nervous system?
The parasympathetic nervous system relaxes the body and returns it to its normal state, by increasing/decreasing functions following a ‘fight or flight’ response
Similarities + Differences of the parts of the CNS
Similarities + Differences of the parts of the CNS:
-Similarity = both brain and spinal cord control involuntary processes
-Difference = brain provides conscious awareness wheras spinal cord responsible for simple reflexes
Similarities + Differences of the parts of the PNS
Similarities + Differences of the parts of the PNS :
-Similarity = sympathetic and somatic respond to external stimuli
-Difference = autonomic consists of two components whereas somatic has only one component
Function of the sensory neurones
Sensory neurones carries information to the CNS
Function of the relay neurones
Relay neurones carry information between sensory and motor neurones
Function of the motor neurones
Motor neurones control muscle movement by carrying info from relay to effector cells
Dendrites
Dendrites recieve signals from other neurones
Axons
Axons are fibres that carry nerve impulses in form of electrical signals called an action potential
Myelin sheaths
Myelin sheaths insulate axons (except for relay neurones) and speeds up transmission
Axon terminals
Axon terminals connect neurones using process called synaptic termi
Synaptic transmission
Synaptic transmission: action potential - carried in synaptic vesicles (neurotransmitters), across synpatic gap by diffusion to postsynaptic neurone - either inhibitory or excitory effects
Excitatory neurotransmitters eg noradenalinie
Excitatory neurotransmitters - makes the post-stynaptic cell more likely to fire - causes an excitaroy post-synaptic potential (EPSP)
Inhibitory neurotransmitters eg GABA
Inhibitory neurotransmitters make post-synaptic cell less likely to fire - results in an inhibitory post-synaptic potential (IPSP)
What is the endocrine system
Endocrine system - network of glands - releases hormones
Glands that make up the endocrine system
Glands that make up the endocrine system:
-Hypothalamus
-Pituiary gland
-Pineal gland
-Thyroid and parathyroid glands
-Thymus
-Pancreas
-Adrenal glands
-Ovary
-Placenta
-Testicle
Role of the hypothalamus?
Hypothalamus - connected to the pituitary gland - responsible for stimulating or controlling the release of hormones from the pituitary gland
Role of the pituitary gland?
The pituitary gland = known as master gland - controls and stimulates release of hormones from other gland
-Divided in to the anterior (front), posterior (read) and lobes - each release different hormones
Key hormones released from the different parts of the pituitary gland
Posterior lobe of the -Pitutiary gland - releases oxytocin (love hormone - uterus contractions during childbirth)
-Anterior love - ACTH - stimulates adrenal cortex to release cortisol
The pineal gland
The pineal gland releases melotonin - responsible for important biological rhythms including the sleep-wake cycle
Thryoid gland
Thyroid gland - releases thryoxine - regulates metabolism
Adrenal gland
Adrenal gland:
-Adrenal cortex - coritsole - stimulates glucose release to provide energy whilst supressing immune system
-Adrenal medulla - adrenaline and noradrenaline
Testes
Testes - releases androgens including tostesterone - development of male sex characteristics
Ovaries
Ovaries - release oestrogen - controls regulation of the female reproductive system including menstruation and pregnancy
Process of adrenaline release
Adrenaline release:
-Stressful situation
-Amgydala activated + sends distress signal to hypothalamus
-Hypothalamus activates SAM pathway
-SNS stimulates adrenal medulla
-Adrenal medulla secrets adrenaline and noradrenaline
Physiological changes brought about by the fight or flight response
Physiological changes brought about by the fight or flight response:
-Increased heart rate - more blood flow
-Increased breathing rate
-Pupil dilates
-Sweat
-Reduction of non-essential functions
Fight or flight response evaluation
Fight or flight response evaluation:
- = third response - freeze
- = counterintuitive for woman - research says woman adopt ‘tend and befriend’ response - more likely to flight - danger
- = conducted moslty on males - androcentrism - beta bias
- = less needed now than compared to ancestors, negative consequences on health - eg high blood pressure if stimulated continuously
What is plasticity?
Plasticity = brain altering both its structure and function -> important for learning and recovery after trauma
What are the 4 main principles of plasticity?
The 4 main principles of plasticity:
-Impulse transmission across neurones
-Neural pathways created as new info is passed between neurones
-The more these pathways are used -> the stronger the connections become
-Connections weaken if pathway is not used regularly
Sperry (1968) - Effects of split-brain surgery - Procedure
Sperry (1968) - Effects of split-brain surgery - Procedure:
-Natural experiment
-11 participants (10 men, 1 woman)
-Range of visual (image flashing) and tactile tests (objects placed in either right/left hand)
Sperry (1968) - Effects of split-brain surgery - Findings
Sperry (1968) - Effects of split-brain surgery - Findings:
-Right visualfield = info can be described
-Left visual field = no memory or description
-Objects in right hand = can be described
-Objects in left hand = guesses, sometimes didnt know they held anything
Sperry (1968) - Effects of split-brain surgery - Conclusion
Sperry (1968) - Effects of split-brain surgery - Conclusion: Findings support the theory that for right handed people, language is processed in the left hemisphere of the brain
Sperry (1968) - Effects of split-brain surgery - Evaluation
Sperry (1968) - Effects of split-brain surgery - Evaluation:
+ = Controlled and standardised -> reliable
- = Small sample
- = Individual differences
- = Lack of ecological validity
Maguire Taxi Study
Maguire Taxi Study: MRI scans -> London taxi drivers -> larger grey matter in brain -> proof of plasticity
What is lateralisation?
Lateralisation is the idea that the no halves of the brais are functionally different and that each hemisphere has functional specialisations
How are the two brain hemispheres connected?
The two hemispheres of the brain are connected by nerve fibres called corpus callosum, which facilitate interhemispheric communication - allowing the left and right to ‘talk’ to eachother
Sperry’s split brain research study aim
Sperrys Split brain surgery aim = theaim of their research was to examine the extent to which the two hemispheres are specialised for their function
What is method used by Sperry in his split brain research:
Sperrys split brain research method: an image/word is projected to the patient’s left visual field (which is processed in the right hemisphere) or the right hemisphere (which is processed by the left hemisphere). When information is presented to one hemisphere in a split-brain patient, the information is not transferred between hemispheres as the corpus callosum is cut
What tasks were involved in Sperry’s split-brain research?
Sperry’s split brain research tasks:
-Describing what patients saw when picture was presented to either left or right visual field
-Tactile test - placing object in either left orright hand and they had to say what they felt
-Drawing task - drawing what they see
Findings of Sperry’ Split-Brain research
Findings of Sperry’ Split-Brain research:
-Description task = Picture presented to right visual field greater description from left hemisphere showing it has better language prouction
-Tactile task = object in right hand clear when processed by left hemisphere, opposite for left hand
-Drawing task = Right hemisphere better at visual motor tasks as drwing better drawn with left hand
Conclusion of Sperry’s split brain research
Conclusion of Sperry’s split brain research = findings highlighted key differences between two hemispheres:
-Left dominant in speech and language
-Right dominant in visual-motor tasks
Split-brain research evaluation
Split-brain research evaluation:
+ = Lateralisation increases neural processing capacity (the ability too perform multiple tasks simultaneously
- = Lateralisation changes with age - questions wether everyone has one hemisphere that is dominant t the other
- = Language may not be restricted to the left hemisphere - Turk discvered a patient who suffered damage to left but could still speak - laterlisatin is not fixed
What are biological rhythms?
Biological rhythms are cyclic patterns within biological systems that have evolvedin response to environmental influences - they are governed by endogenous pacemakers and exogenous zeitgebers
What is the circadian rhythm?
The circadian rhythm is a 24-hour clock which is reset by the levels of light, including our sleep-wake cycle
What is an infradian biological rhythm?
Infradian biological rhythm = rhythm that lasts longer than 24 hours, such as the female menstrual cycle
What is an ultradian biological rhythm?
Ultradian biological rhythm = lasts less than 24 hours -> found in patterns of human sleep -> REM (rapid eye movement) and NREM (non-rapid movement)
-Consists of 5 stages: light sleep -> deep sleep -> REM sleep -> brain waves speed up and dreaming occurs
What are endogenous pacemakers?
Endogenous pacemakers are internal mechanisms that govern biological rhythms
-Most important pacemaker = Superchiasmatic Nucleus (SCM), which is closely linked to the pineal gland which releases melatonin
What are exogenous zeitgebers?
Exogenous zeitgebers are environmental events that are responsible for resetting the biological clock
-Social cues such as mealtimes and social activities
-Temperature
-Light
Siffre Case study
Siffre case study:
-‘Caveman’ who spent time underground to study the effects on his biological rhythms
-Free-running biological rhythm was set to 25 hours, but did continue to sleep and follow his regular sleep schedule, despite lack of real light and sound exposure (his only light source was artifical)
Endogenous pacemakers + Exogenous Zeitgebers Evaluation
Endogenous pacemakers + Exogenous Zeitgebers Evaluation:
+ = Research -> Decoursey removed chipmunk’a SCN and proved importance of biological rhythms as sleep-wake cycle was interrupted
- = Decoursey’s chipmunks was unethical as they died to predators as a result, it is also hard to generalise findings to humans
- = Biologically reductionist
Biological Rhythms Evaluation (circadian rhythms)
Biological Rhythms Evaluation (circadian rhythms):
+ = Practical application to shift work - night shift workers = economic implicaiton
+ = practical application to drug treatment -> time of day when drugs are most effective
- = Use of case studies + small samples (Siffre)
- = Individual difference
- = Biological reductionism
A03 evaluation of ultradian rhythms
A03 evaluation of ultradian rhythms:
+ = Research conducte duner laboratory experiments = eg use of EEG when looking at sleep stages
- = Artificial lab experiments - sleeping under unusual conditions
- = Androcentric lab findings -> eg Dement’s experiment into sleep stages using male participants -> physiological differences?
Dement and Kleitman EEG research into Ultradian Rhythms
Dement and Kleitman EEG research into Ultradian Rhythms:
-Used EEG to identify systematic changes in brain waves at regular intervals in sleep
-Used 9 male participants upto 61 nights in a lab - found two types - REM sleep and NREM sleep (no rapid eye movements)
-79% of people when woken up during REM had dreams, 7% from NREM
Physiology of the Infradian Rhythm cycle of menstruation
The Physiology of the Infradian cycle of Menstruation:
1. Relates to activity in the endocrine system that prepares the womb for the possibility of conception after egg cells are released.
2. Hormones are controlled by pituitary gland. Each cycleends with menstruation (unless pregnancy occurs).
3. The pituitary gland may be influenced by levels of light and the secretion of melatonin and this is supported by research.
This suggests that the infradian rhythm of menstruation is controlled mainly by internal factors (endogenous pacemakers).
McClintock rearch into dormitory effect on menstrual synchrony
McClintock rearch into dormitory effect on menstrual synchrony:
-Cycles of women became synchronised due to pheromones (smell chemicals when secreted, causing specific reactions in other individuals)
-Further investigated with older woman with irregular periods, found that when smelling chemicals caused a response
Infradian Rhythms AO3 Evaluation
Infradian Rhythms AO3 Evaluation:
+ = Supporting research -> Barnard found women who spent a lot of time together had synchronised periods due to pheromones -> shows biological rhythms are controlled both by EP’s and EZ’s)
- = Not entirely ethical research from McClintock -> as woman’s menstrual cycles have been purposely changed -> effects of this unknown
- = Studies are field experiments -> less control over extraneous variables -> cannot confirm causality
What are the 4 ways of studying the brain?
Ways of studying the brain:
-> fMRI
-> EEG
-> ERP’S
-> Post-martem examinatiion
What is fMRI + evaluation?
fMRI = Detects changes in O2 of blood
+ = No radiation and non-invasive
- = Doesn’t measure electrical activity
What is EEG and evaluation?
EEG = Measures electrical activity
+ = Diagnosis of epilepsy
- = Source unclear
What is ERP and evaluation?
ERP = Analysis of EEG data
+ = Finds neuronal source
- = Lack of standardisation across research
What are post-martem examinations and evaluation?
Post-martem examinations = analysis of brain after death
+ = Scientific advancements
- = Lack of causation
