6. Biopsychology Flashcards
Assumptions of biopsychology?
- Everything that is psychological is first biological.
- We have through selective adaptation.
- Looking at biological structures and processes within the body such as genes, the nervous system and neurochemistry, brain structure to explain our behaviour.
Research methods used in biopsychology?
- MZ and DZ twins.
- Family studies.
- PET scans, fMRIs and neurosurgery.
- Natural selection (Darwin).
What are the two branches off of the HNS?
Peripheral nervous system (PNS), central nervous system (CNS).
What are the two branches off of the PNS?
Somatic nervous system and the autonomic nervous system.
What are the two branches off of the autonomic nervous system?
Sympathetic nervous system and the parasympathetic nervous system.
What are the two branches off of the CNS?
Brain and the Spinal Chord.
What is the role of the brain?
The brain receives and processes all incoming information from the sense.
It then generates a response – it controls the behaviours that may result from a stimulus in our environment.
What is the role of the CNS in human behaviour?
The CNS acts as an information processing and control centre for information we receive and responses that we make in our environment.
What is the role of the spinal cord?
Relays information between brain and body.
What is the role of the somatic nervous system?
To carry sensory information from the outside world to the brain and provide muscle responses via these motor pathways that allow us to respond to the environment.
What features allow the somatic nervous system to carry out its role?
- Sensory receptors: carry information to spinal cord and brain.
- Motor pathways: allow brain to control movement.
What is the role of the autonomic nervous system?
Transmits information to and from internal organs to sustain life. Plays an important part of homeostasis which maintains internal processes. Carries out actions without your conscious awareness.
What is the autonomic nervous system made up of?
Motor pathways.
What is the role of the sympathetic system?
Increased bodily activity for the fight/flight response.
Examples:
- Dilates pupils.
- Accelerates heartbeat.
- Inhibits peristalsis
- Secretion of adrenaline.
What is the role of the parasympathetic system?
Maintains normal bodily activity (homeostasis) for example rest/digest actions. Acts as a brake and reduces the activities of the body that have been increased by sympathetic nervous system.
Examples:
- Slows heartbeat.
What is the cerebrum?
The cerebrum is referred to as the ‘wrinkles’ - it is the largest part of the brain and it is divided into four lobes.
What is the corpus callosum?
The hemispheres are joined together by a massive bundle of neurones called the ‘corpus callosum’. The main function of the corpus callosum is to ensure the two hemispheres are able to communicate with each other.
What is the cerebellum?
The cerebellum sits at the back of the cerebrum. Controls motor skills and balance, coordinates muscles to allow for precise movement.
What is the brain stem?
The brain stem is the lowest part of the brain regulates essential functions for life, for example breathing, heartbeat and swallowing. Also connects the brain to the spinal cord.
What is the brain stem made up of?
The brain stem is made up of three parts – midbrain, pons, medulla.
Where is the frontal lobe?
They sit just inside the front of the skull.
What is the role of the frontal lobe?
- Planning & organizing.
- Problem solving.
- Memory & attention.
- Controlling behaviour, emotions & impulses.
Where is the parietal lobe located?
Behind the frontal lobe.
What is the role of the parietal lobe?
- Integrate sensory information from various parts of the body.
- Contain the primary sensory cortex, which controls sensation.
- Tell us which way is up.
- Help to keep us from bumping into things when we walk.
Where is the occipital lobe?
Lower back of the head.
What is the role of the occipital lobe?
- To receive and process visual information
- Contain areas that help in perceiving shapes and colours.
Where is the temporal lobe?
On the sides of the brain, under the parietal lobes, and behind the frontal lobes.
What is the role of the temporal lobe?
- Recognizing and processing sound.
- Understanding and producing speech.
- Various aspects of memory.
Where is the diencephalon located?
Beneath the cerebrum and above the brain stem.
What does the diencephalon contain?
Contains the thalamus and hypothalamus.
What is the thalamus’ function?
To transfer the information it collects from other parts of the brain to the cerebral cortex. It also regulates sleep, alertness and wakefulness.
What is the hypothalamus’ function?
It regulates body temperature, hunger, thirst. It also links to the endocrine system to control release of hormones.
What is plasticity?
Brain plasticity refers to the brain’s ability to change and adapt because of experience.
What is the function of the axon?
A long branch from the cell body that passes electrical impulses down the end of the neuron to allow it to communicate with others.
What is the function of the dendrites?
Branches at the top end of a neuron that receive messages from other neurons.
What is the function of the cell body?
The main part of the cell where the nucleus sits. It also contains mitochondria.
What is the function of the nucleus?
A cell within the nervous system – it stores the neuron’s DNA.
What is the function of the axon hillock?
Generates the electrical impulse to travel down the axon.
What is the function of the myelin sheath?
The fatty deposits that provides electrical insulation, it speeds up the action potential.
What is the function of the Nodes of Ranvier?
Gaps between adjacent myelin sheaths, which speed up action potential.
What is the function of synapses?
The gap between the pre-synaptic neuron and the post-synaptic neuron. This is where neurotransmitters are released.
What is the function of Schwann Cells?
A type of glial cell (cells that hold nerve cells in place and help them work the way they should) and helps hold the myeline sheath together.
What is the function of the axon terminal?
Transmits messages via neurotransmitters to other neurons.
What is the role of the motor neuron?
Take messages from brain & spinal cord (CNS) TO muscles & glands.
What is the role of sensory neurons?
Receive messages from senses and send these messages to the CNS.
What is the role of the relay neuron?
Only found in CNS. Connect neurons to other neurons in the CNS, including sensory and motor neuron.
Summary of synaptic transmissions.
- Pre-synaptic neuron – electrical impulse travels down the axon and arrives at synaptic terminal.
- The vesicles release neurotransmitters, electrical impulse binds, becomes chemical and diffuses across the synaptic gap
3) Neurotransmitters bind with receptors on the post-synaptic neuron.
4) If the summation (overall charge of the impulse) is positive then the post-synaptic neuron will fire (excitatory) and the impulse continues.
5) If the summation is negative then the post-synaptic neuron will not fire (inhibitory).
6) Neurotransmitters are then:
- Broken down by enzymes in the synapse.
- Reabsorbed (reuptake) by the pre-synaptic neuron ready for the next impulse.
- Diffused away.
What is an excitatory repsonse?
It makes it more likely that the next neuron will fire.
→ When the neurotransmitters bind to the receptors on the post-synaptic membrane, the post-synaptic neuron becomes positively charged and an action potential is created.
What is an inhibitory response?
It makes it less likely that the next neuron will fire.
→ When the neurotransmitters bind to the receptors on the post-synaptic membrane, the post-synaptic neuron becomes negative charged and an action potential is not created.
What is the role of the endocrine system?
- Supplements the work of the nervous system.
- Regulates cells and organs in the body
What is the endocrine system made up of?
- A network of glands throughout the body that manufacture and secrete hormones.
- The endocrine system uses blood vessels to deliver hormones to their target site in the body.
What is the ‘master gland’?
Pituitary gland.
Hormones definition?
Hormones: chemical substances produced in a specialised gland and transported in blood to stimulate specific cells or organs into action.
Where is the command centre of the endocrine system?
In the hypothalamus.
What happened when enough receptor sites are stimulated by a hormone?
A physiological reaction occurs in the target cell.
What are the two parts of the pituitary gland?
o The posterior is the back of the pituitary gland which controlled oxytocin
o The anterior ACTH (Adrenocorticotropic hormone) – stimulates production of cortisol (stress!).
Where is the hypothalamus and what hormones does it release?
- Location: Brain
- Hormones: Oxytocin and antidiuretic hormone.
What is the effect of the hormones released by the hypothalamus on the body?
- Regulates the pituitary gland.
- Maintains homeostasis.
- Influences stress response, reproductive behaviour, and emotional states.
Where is the pituitary gland and what hormones does it release?
Location: Brain.
Hormones:
- Anterior: ACTH (FSH and LH in women.
- Posterior: oxytocin and ADH.
What is the effect of the hormones released by the pituitary gland on the body?
- Controls growth, metabolism, stress response, milk production, and reproductive processes.
- Stimulates other glands like the thyroid and adrenal glands.
Where is the pineal gland and what hormones does it release?
Location: Brain
Hormones: Melatonin
What is the effect of the hormones released by the pineal gland on the body?
- Regulates sleep-wake cycle.
- Influences seasonal biological rhythms.
Where is the adrenal gland and what hormones does it release?
Location: on the top of each kidney.
Hormones:
- Cortex: cortisol, aldosterone and androgens.
- Medulla: adrenaline, noradrenaline.
Explain the role of adrenaline.
- Fight or flight helps an individual to react quickly to a threatening or stressful situation.
- The heart beats faster, breathing becomes more rapid, muscles tense. These reactions is the flight or fight response.
- This is a survival mechanism enabling humans and animals to react quickly to life threatening situations.
Describe the process for an acute stress response.
- The amygdala associates sensory signals with emotions such as fear and sends a ‘distress signal’ to the hypothalamus.
- The hypothalamus in response to the threat releases CRH into the bloodstream.
- The sympathetic nervous system prepares the body for fight or flight.
- The adrenal medulla releases adrenaline into the bloodstream, stimulating increased heart rate and release of blood sugar.
- When the threat has passed the parasympathetic nervous system dampens down the stress response that you felt.
Describe the process for a chronic stress response.
- The amygdala associates sensory signals with emotions such as fear and sends a ‘distress signal’ to the hypothalamus.
- The hypothalamus in response to the threat releases CRH into the bloodstream.
- The sympathetic nervous system prepares the body for fight or flight.
- The adrenal medulla releases adrenaline into the bloodstream, stimulating increased heart rate and release of blood sugar.
- If the brain continues to perceive something as threatening the chronic second system kinks in – HPA Axis.
- The hypothalamus releases CRH into the bloodstream.
- CRH causes the pituitary gland to release ACTH into the bloodstream and from there to its target site in the adrenal gland.
- The adrenal cortex releases stress hormones including cortisol in response to stress.
- The feedback system, cortisol levels are monitored so that CRH and ACTH production is inhibited if cortisol is too high.
Strengths of the fight or flight explanation.
- We know from this model that the response may be stimulated for a situation that does require the same amount of energy that was needed in the past. As a result our body can overwork and damage our heart; therefore we know that it is important to keep stress low.
- Genetic differences – research has been conducted into the different responses in men and women. Lee and Harley (2012) found evidence of a genetic basis for gender differences in the fight-or-flight response.
Weaknesses of the fight or flight explanation.
- Lack of generalisability – the findings are drawn on research of mainly males. Taylor et al. suggested that for females behavioural responses to stress are characterised by a pattern of tend and befriend because of higher oxytocin levels.
- Not the whole picture – Gray (1988) argued that there is a third ‘freeze’ response.
- Real world scenarios – Von Dawans et al. found that acute stress can lead to greater cooperative and friendly behaviour. This could explain the behaviour of NYC residents during the 9/11 terrorist attacks.
Definition of localisation of function?
The theory that specific areas of the brain are associated with physical and psychological functions.
What happened to Phineas Gage?
- He was a railroad worker who survived a severe brain injury when an iron rod was driven through his skull.
- His accident, in 1848, led to changes in his personality.
How did Gage provide evidence for localisation of function?
He provided evidence that the frontal lobe plays a key role in personality, and different parts of the brain have different functions.
What are the issues with case studies such as that of Gage?
- Hard to generalise.
- We cannot replicate.
- Ethical issues – the person doesn’t know they are being studied and don’t know they can consent to withdraw.
- Retrospective data – there is no context, so we rely of anecdotal data.
What are the three concentric layers of the brain?
The central core, the limbic system and the cerebrum.
What is the role of the central core?
This regulates our most primitive and involuntary behaviours such as breathing, sleeping or sneezing.
Where is the central core found?
Found in the centre of the brain to protect it the most.
What is the central core comprised of?
It includes the brain stem and regulates the endocrine system (hypothalamus, pituitary gland).
What is the role of the limbic system?
Controlling our emotions.
Where is the limbic system found?
Around the central core.
What is the limbic system comprised of?
The hippocampus.
What is the role of the cerebrum?
This regulates higher intellectual processes.
What is the cerebrum comprised of?
The cerebrum is made up of the left and right hemisphere which are connected by a bundle of fibred called the corpus callosum.
What is lateralisation?
The dominance of one hemisphere of the brain for particular physical and psychological functions.
What is Broca’s Area?
Broca’s Area is a region in the frontal lobe of the brain, typically in the left hemisphere, associated with speech production and language processing.
What does Broca’s area control?
Controls speech production, language comprehension, and grammar processing.
What does Broca’s aphasia cause?
Causes difficulty in speech production however, comprehension remains relatively intact.
What is Wernicke’s area?
Wernicke’s area is a region of the brain located in the superior temporal gyrus of the left hemisphere, near the auditory cortex.
What does Wernicke’s area control?
It is primarily responsible for language comprehension, including the understanding of spoken and written language.
What does Wernicke’s aphasia cause?
Fluent but nonsensical speech and difficulty understanding language.
What are the strengths of the localisation of function theory?
- Brain scan evidence:
o The research of Petersen et al. used brain scans to show how Wernicke’s area was active during a listening task and Broca’s was active during reading. - Neurosurgery:
o Walter Freeman developed the lobotomy to control aggressive behaviours.
o Dougherty et al. (2002) reported that one third of the 44 OCD patients who had undergone cingulotomy had a successful response. - Phineas Gage – case studies such as that of Phineas Gage further support the theory of localisation of function within the brain.
What are the weaknesses of the localisation of function theory?
- Contradictory research - Karl Lashley (1950) suggested that higher cognitive functions are not localised - through an experiment on rats in a maze.
- Plasticity – this suggests that when the brain has become damaged the rest of the brain appears to be able to reorganise itself to recover (best it can) the lost functions.
- Issues with case studies – much of the early research into localisation came from the case study of Phineas Gage however this had many issues.
- Ethical issues – some research into localisation of function has been unethical.
o Case studies – the person doesn’t know they are being studied and don’t know they can consent to withdraw.
o Neurosurgery – during the 1950s many people didn’t have the choice about the surgery that was performed on them.
What is the left side of the brain responsible for?
- Processes information from the right side of the body.
- Views objects in right visual fields.
- Known as the “major hemisphere” as it processes language.
- Logical thinking / Analysis / Controlling emotions.
What is the right side of the brain responsible for?
- Processes information from the left side of the body.
- Views objects in the left visual fields.
- Known as the “minor hemisphere” as it cannot process language.
- It contributes to emotion context to words.
- Facial recognition and creativity.
What is the optic chiasm?
The optic chiasm is where the optic nerves from each eye cross, allowing visual information from both eyes to be processed by both hemispheres of the brain.
What was the aim of Sperry’s 1968 experiment?
To examine the extent to which the two hemispheres are specialised for certain functions.
What procedure had Sperry’s participants undergone prior to the experiment?
A commissurotomy (where the corpus callosum is cut). They had it to treat their severe epilpsy.
What were the three different tests that Sperry conducted on the participants?
- Visual.
- Tactile.
- Verbal.
Outline the procedure of Sperry’s experiment?
- He asked his participants to gaze at a fixation point in the centre of the screen.
- Images or words are flashed to either side of the fixation point very briefly (1/10th sec).
- This tests what they are seeing in each visual field.
- The subject is then asked to either say what they saw, write what they saw or to feel from a hidden selection of objects to choose the one that matches what they thought they saw.
Outline some of the key findings from the experiment.
- When an object is displayed in the RVF participants can describe it in speech and writing.
- When an object is displayed in the LVF participants cannot say what they have seen and instead say they have seen nothing.
- But if asked to use the left hand to feel for to a matching object on the table they can do so, while still insisting nothing was seen.
Give three examples of specific results from Sperry’s experiments.
- Describe what you see:
- Patient saw a picture (cat) in their LVF.
- They reported seeing nothing at all. - Tactile tests:
- The patient has an object (banana) placed in their left hand they cannot see it.
- They made wild guesses as to what the object was.
- When given the chance to identify the object by touching it as well they could complete the task. - Drawing task:
- A picture (Key) is presented in the LVF.
- They could draw beautiful image with the left hand (even if they were right handed).
Strengths of Sperry’s research.
- Ethics: the participants had already had the surgery.
- Very scientific: high control everyday items, increases the internal validity and mundane realism.
- Practical application: helps us to inform people that the side effects of the surgery is dramatic.
Weaknesses of Sperry’s research.
- Small sample size: only 11 people were involved in the study.
- Participants had had the surgery at different points from a few weeks to 5 years.
- The validity could be lowered because participants may have showed demand characteristics.
- Reductionist: all the tasks were typical left/right brain tasks rather than holistic tasks that included both hemispheres.
What are post mortems and what are they used for?
- The role of a post mortem is to investigate the brain after death.
- If a person had an affliction in their lifetime, the brain can be acquired and investigated.
What are PET scans and what are they used for?
- PET scans allow us to see the activity that is occurring in the brain.
- The scans detect the metabolism of substance and show which parts of the brain are most active (using up glucose energy) over a period of minutes.
What is the process of PET scans?
o A small amount of harmless radioactive substance is injected into the patient.
o The radioactive material bind to glucose forming a tracer.
o When the brain uses glucose for energy, the area of the brain which are most active absorbs the tracer.
o The radioactive material emits positively charged particles called positrons, which are subsequently picked up by the scanner.
o This information allows a computer to produce coloured images of the level of activity occurring throughout the brain.
What are MRIs and what are they used for?
- MRIs allows us to investigate the structure of the brain.
- Strong magnetic waves are sent through the body.
- The body sends out its own radio waves.
- The scanner picks up these signals and the computer turns them into an image.
What are fMRIs and what are they used for?
- fMRI scans allow us to observe and measure brain function rather than just the structure of the brain.
- Studies the areas that are currently active.
- They work by detecting blood oxygenation to each area of the brain. This is called the B.O.L.D. signal (Blood-oxygen level dependent Signal).
What are EEGs and what are they used for?
- EEGS are when electrodes are placed on the surface of the skull.
- They measure changes in electrical activity when they performs a specified task. This is recorded as a crude measurement shown in waves.
- They can be used to diagnose epilepsy and brain death.
What are ERPs and what are they used for?
- Patients undergo multiple ERPs and are presented with a specific stimulus more than 50 times.
- The signals are averaged out so extraneous signals diminish and the signal related to the event remains.
- By removing the background noise of general brain activity, researchers can see which electrical activity occurred in response to the event.
Strengths of post mortems?
- PMs were vital in providing a foundation for understanding of processes in the brain.
- Both Broca and Wernicke relied on PM studies in establishing inks between language, brain and behaviour.
- PM studies improve medical knowledge and help generate hypotheses for further studies.
Weaknesses of post mortems?
- Causation: observed damage to the brain may not be linked to the deficits under review.
- Ethical issues of consent from the patient before death. Patients may not be able to provide informed consent.
Strengths of MRIs/fMRIs?
- MRIs have high spatial resolution: meaning you can see many fine details.
- No radiation and non-invasive so there are fewer risks to the patient.
Weaknesses of MRIs/fMRIs?
- Low temporal resolution there is approximately a 5 second time lag – this means the patients have to stay still for a long period of time.
- Expensive.
- A limited range of stimuli/responses can be measured (sleep, hallucinations etc).
- Not always possible to replicate some activity in the scanner.
Strengths of EEGs?
- EEGs are useful in the diagnosis of epilepsy – bursts of activity in the brain can be easily detected.
- They have contributed much to our understanding of the stages of sleep.
- Has extremely high temporal resolution.
Weaknesses of EEGs?
- EEGs tend to produce generalised information so it isn’t useful for pinpointing the area of neural activity.
- EEGs do not allow researchers to distinguish between activity originating in different but adjacent locations of the brain.
Strengths of ERPs?
- ERPs bring much more specificity to the measurement of neural processes than EEPs.
- Excellent temporal resolution.
- Use in the measurement of cognitive functions and deficits.
- Researchers have been able to identify different types of ERP and describe the precise role of these in cognitive functioning including parts of working memory.
What are the three main types of biological rhythms?
- Circadian.
- Ultradian.
- Infaradian.
How long is the circadian rhythm?
Around 24 hours.
How long is the ultradian rhythm?
Less than 24 hours.
How long is the infaradian rhythm?
More than 24 hours
What are all biological rhythms regulated by?
- Endogenous pacemakers
- Exogenous zeitgebers
What are endogenous pacemakers?
The body’s internal body clocks that regulates biological rhythms.
What are exogenous zeitgebers?
External factors in the environment which reset our biological clocks.
What was the aim of Michel Siffre’s research?
To see whether desynchronisation can occur.
Outline the procedure of Siffre’s work.
- Siffre spent 2 months living in total isolation in a cave, without access to clock, calendar, or sun.
- Sleeping and eating only when his body told him to, his goal was to discover how the natural rhythms of human life would be affected by living “beyond time”.
- After a 2 month cave stay, he then lived in a cave for 6 months. The lights came on when he woke and went off when he slept.
What did Siffre find?
- He settled into a sleep/wake cycle of 25 to 30 hours.
- His sleep/wake cycle had become desynchronised.
What other studies have been conducted on the idea of desynchronisation?
- Aschoff and Wever (1976)
- Czeisler et al (1999)
- Folkard et al. (1985)
What did Aschoff and Wever (1976) find?
The participants of their experiment (in a WW2 bunker) settled into a sleep/wake cycle of 25-27 hours.
What did Czeisler et al (1999) find?
Argued that the use of bright lights was artificial. Their experiment in low light conditions resulted in a circadian cycle of 24hrs 11 mins.
What did Folkard et al. (1985) find?
They sped up the pace of clocks to be 22 hour days rather than 24 - none of the subjects could adjust comfortably to the pace of the clock.
Strengths of the idea of circadian rhythms?
- Practical applications in shift work and drug administration.
Weaknesses of the idea of circadian rhythms?
- Siffre’s research is only a case study - lacks generalisability.
- Poor control in the studies.
What is the SCN?
The SCN is a tiny bundle of nerve cells located in the hypothalamus.
What does the SCN do?
It receives information about light directly from this structure – this continues ever when the eyes are closed enabling the biological clock to adjust itself.
Outline the 2 animal studies conducted relating to the endogenous pacemakers?
- Patricia DeCoursey et al. destroyed the SCN connection in chipmunks: the sleep/wake cycle disappeared.
- Martin Ralph et al. bred hamsters with 20h sleep cycles - when this tissue was transplanted to normal hamster the cycles of the 2nd group defaulted to 20h.
What is the role of the pineal gland in the sleep/wake cycle?
The SCN passes information on day length and light that it receives to the pineal gland. During the night the pineal gland increases production of melatonin.
How does light play a role in the sleep/wake cycle?
Light can reset the body’s main endogenous pacemaker, the SCN and thus plays a role in maintenance of the sleep/wake cycle. Light is also an indirect influence on the key processes in the body that control such functions such as blood circulation and hormone secretion.
Who researched skin being detected by skin receptors?
Scott Campbell and Patricia Murphy.
What did Scott Campbell and Patricia Murphy find.
By shining a light pad on the back of the participants’ knees they were able to make the usual sleep/wake cycle deviate from its norm.
