Psychology - Biopsychology

Julia complains that her baby is sleeping all day and keeping her awake all night.

Using your knowledge of research into exogenous zeitgebers, discuss what Julia could do to encourage her baby to sleep more at night. (8 marks)

3 AO1; 2 AO2; 3AO3

ao1

• external cues acts zeitgebers

• these cues may influence biological rhythms

• light supresses melatonin production from pineal gland → influences wake cycle

ao2

• julia should keep the baby in the dark at night (shutting of curtains) , expose baby to light during the day (keep curtains open; go outside)

• only use social cues (verbal communication, eye contact, feeding) during the dau

ao3

siffre (1962) →lived in cave with no natural light for several months → sleep-wake cycle extended beyond 24 hours → absence of light cues causes disruption of biological rhythms → lack of external time cues → demonstrates the role of light as zeitgebers

Outline and evaluate one or more ways of studying the brain. (8 marks)

ao1

• studying the brain allows us to gain important insights into underlying foundations of behaviour and mental processes

• fMRI → magnetic field and radiowaves to monitor blood flow → measures the change in the energy released by haemoglobin, reflecting brain activity → activity in brain regions compared during base line & specific activities

• EEGs →measures electrical activity by attaching electrodes on scalp → small electrical charges detected by electrodes → indicates level of activity

• ERPs → measures small voltage changes in the brain in response to a stimuli introduced by reseacher

ao3

• 🙂 → EEG has good temporal resoultion → takes readings every millisecond → records brain activity in real time as opposed to looking at a passive brain → accurate measurements of electrical activity when responding to a specific task → 😕 → EEGs are uncomfrotable → electrodes are uncomfortable when attached to head → patient’s discomfort may cause unrepresentative readings due to possible impact of cognitive responses to situations → fMRIs are non-invasive → no patient discomfort → more accurate recordings

• 🙂 → ERPs cheaper, more widely used in research → enables determination of how processing is affected by specific experimental manipulation → more experimentally robust method → eliminates extraneous neural activity

Explain the process of synaptic transmission. (4 marks)

• action potential reach presynaptic terminal

• action potential triggers the release of neurotransmitters from synapse vesicles

• neurotransmitters diffuse across the synaptic cleft

• neurotransmitters bind to receptors on the postsynaptic membrane

A psychologist wanted to test the effects of biological rhythms on the ability to solve maths problems. She used random sampling to form two groups each of 20 students.

She tested one group on one set of maths problems at 3 am in the morning. The other group were tested on another set of maths problems at 3 pm in the afternoon. She found that performance of the group tested at 3 pm was significantly better than the group tested at 3 am.

When submitted for peer review the paper was rejected because of serious design problems.

Explain one problem with the design of this study and suggest ways of dealing with this problem. (4 marks)

• random sampling problem → group used at 3pm might have just been better than 3am group

• solution → matched pairs design (matched on math ability eg)

Briefly evaluate the use of EEGs as a way of identifying cortical specialisation in the brain.

(Total 3 marks)

• safe way of measuring brain activity

• takes readings every millisecond → records brain activity in real time opposed to passive brain activity

• electrodes uncomfortable → unrepresentative readings due to patients discomfort messing up cognitive responses

The electroencephalogram (EEG) and event-related potentials (ERPs) both involve recording the electrical activity of the brain.

Outline one difference between the EEG and ERPs. (2 marks)

• eegs measure general activity in the brain over time

• erps are specific patterns of brain activity linked to particular stimuli

Explain one difference and one similarity between Functional Magnetic Resonance Imaging (MRI) and Event-Related Potentials (ERPs) as ways of studying the brain. (4 marks)

• fmri have poor temporal resoltuion, erps have good temporal resolution

• fmris and erps both are non-invasive and don’t use radiation

Outline one example of a circadian rhythm.

(Total 4 marks)

• sleep-wake cycle

• 24 hour periodicity

• controlled by internal body clock →the scn in hypothalamus

• influenced by external cues such as light →regulates melatonin made in pineal gland which makes us feel sleepy

• melatonin levels increase at night to help us sleep → light exposure during the day reduces melatonin to stay awake

Outline one or more examples of ultradian rhythms. (4 marks)

• sleep cycle

• less than 24 hours → repeats approx every 90 min

• alternates between rem and nrem ( n1, n2, n3) sleep during the night

• during the night, we cycle through the stages multiple times → rem stages get longer as the night goes on

• helps with physical restoration and memory consolidation

Biological rhythms are influenced by endogenous pacemakers and exogenous zeitgebers.

Outline the difference between endogenous pacemakers and exogenous zeitgebers.

Use examples in your answer.

(Total 2 marks)

• endogenous pacemakers are internal; exogenous zeitgebers are external

• eg, effects of SCN (endogenous) & light (exogenous)

Sam is a police officer. She has just started working the night shift and after a week, she finds that she has difficulty sleeping during the day and is becoming tense and irritable. Sam is also worried that she is less alert during

the night shift itself.

Using your knowledge of endogenous pacemakers and exogenous zeitgebers, explain Sam's experiences.

(Total 4 marks)

• endogenous pacemakers - internal biological rhythms

• exogenous pacemakers - external factors eg, light

• moving to night shifts means pacemakers try to impose inbuilt rhythm of sleep, but now out of synchrony due to light

• disruption of this leads to disrupted sleep patterns → increased anxiety and decreased alertness and vigilance

Josie is twelve. Last year she was involved in a serious road accident and suffered head injuries that caused problems with speech and understanding language. Now, a year later, Josie has recovered most of her language abilities.

Using your knowledge of plasticity and functional recovery of the brain after trauma, explain Josie's recovery. (4 marks)

• josie is young → recovery from trauma more likely while brain is still maturing

• transfer of functions to undamaged areas (neural reorganisation) which explains her recovery

• growth of new neurons to compensate for damaged areas (neural regeneration), explains her recovery

• plasticity allows brain to cope better with indirect effects of brain damage → eg, swelling

Outline and evaluate split-brain research. (8 marks)

AO1 (3 marks):

• Split-brain research involves patients who have had their corpus callosum severed, usually to reduce severe epilepsy. This prevents communication between the two hemispheres.

• Sperry’s (1968) studies involved presenting information to one hemisphere at a time using a special setup (e.g. a fixation point with images flashed to either the left or right visual field).

• Findings showed that when an image was presented to the left visual field (processed by the right hemisphere), patients could not verbally describe it, suggesting language is localised in the left hemisphere.

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AO3 (5 marks):

• + High scientific control: Sperry’s experiments were well-controlled and standardised, increasing the reliability of the results.

• + Demonstrated lateralisation: The research provided strong evidence for hemispheric lateralisation, especially how the left hemisphere is dominant for language.

• - Small sample size: The studies used a very small number of participants (often under 20), limiting generalisability.

• - Unusual sample: All participants had severe epilepsy, which may have affected their brain functioning — not representative of the general population.

• - Oversimplified hemispheric functions: Later research shows that the two hemispheres are more integrated and not as clearly separated in their roles as Sperry suggested.

Lotta's grandmother suffered a stroke to the left hemisphere, damaging Broca's area and the motor cortex.

Using your knowledge of the functions of Broca's area and the motor cortex, describe the problems that Lotta's grandmother is likely to experience. (4 marks)

• damage to broca’s area - likely to suffer from language / speech problems

• affects language production but not language comprehension

• her grandmother will be only be able to talk in short meaningful sentences → takes great effort

• damage to motor cortex → suffer from muscle paralysis → motor impairments on the right side of the body

Lotta worries that because of her grandmother's age she will not be able to make

any recovery.

Using your knowledge of plasticity and functional recovery of the brain after trauma, explain why Lotta might be wrong. (4 marks)

• might still be capable of functional reorganisation

• functional compensation by other undamaged areas

• although her brain is older, it might still be able to form new connections between neurons (axons and dendrites)

• neuronal loss may be compensated for by regeneration

The adrenal gland is part of the endocrine system that produces adrenaline to help the body prepare for the fight or flight response.

Using an example of a gland and hormone, outline the function of the endocrine system.

Do not use the adrenal gland/adrenaline as your example.

(Total 4 marks)

• the endocrine system helps to regulate the activity of the cells and organs in the body

• communicates chemical messages to the organs of the body

• thyroid gland produces thyroxine → increases heart and metabolic rates

• the pineal gland produces melatonin → helps regulate the wake-sleep cycle

Martha was telling her friend Sanya about her recent frightening experience.

I was walking home by myself in the dark. Suddenly, I heard footsteps behind me and I realised that someone was getting closer to me. I saw a bus at the bus stop and decided to run. I don't think I have ever moved with such speed. I leapt on the bus - shaking, sweating and my heart was beating so fast I nearly collapsed.'

Outline the role of the central nervous system and autonomic nervous system in behaviour. Refer to Martha's frightening experience in your answer. (4 marks)

AO1 (2 marks):

• The central nervous system (CNS), made up of the brain and spinal cord, processes information and coordinates the body's responses.

• The autonomic nervous system (ANS) controls automatic bodily functions and is divided into the sympathetic and parasympathetic branches.

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AO2 (2 marks):

• In Martha’s case, her CNS processed the sound of footsteps and sent signals to trigger a response.

• Her sympathetic nervous system was activated, causing physical symptoms like a racing heart, sweating, and preparing her body to run (fight-or-flight response).

Xavier was cycling to school when he fell off his bike into the road. A teacher saw a car

what had happened.

swerve, narrowly missing Xavier. The teacher checked Xavier was safe and asked him Xavier could hardly speak; his heart was pounding, and his mouth was dry. He felt sick and his hands were shaking. It took Xavier 20 minutes to feel calm again.

Outline the fight or flight response and use this to explain what Xavier was experiencing.

(Total 6 marks)

• F or F response generated by the sympathetic branch of the autonomic nervous system

• SNS stimulates the adrenal medulla to release adrenaline into the bloodstream and noradrenaline is released

• generalised effects of adrenaline → increased breathing rate, sweating, pupil dilation

• xavier shaky hands caused by adrenaline → increases muscle tension

• adrenaline inhibits saliva production - xavier’s dry mouth

• once the stressor is gone, parasympathetic nervous system acts to dampen the stress response and return heart rate back to resting level → explains why after 20 min after xavier calmed down

Jeremy is digging in the garden. He feels the spade hit a rock and stops digging

immediately.

Explain how sensory, relay and motor neurons would function in this situation.

(6 marks)

• sensory neurons send info from the senses to the brain → receptors in jeremy’s hands sense the jolt of the spade hitting the rock & send info via peripheral nervous system to his brain

• relay neurons connect with other neurons, mostly found in the brain → they would be involved in analysis of the sensation, deciding how to respond

• motor neurons send messages via long axons from the brain to the muscles → message from brain instructs jeremy’s arm muscles to stop working and stop the digging action

You are walking home at night. it is dark and you hear someone running behind you. Your breathing quickens, your mouth dries and your heart pounds. Then you hear your friend call out, "Hey, wait for me! We can walk back together," Your breathing slows down and after a couple of minutes you are walking home calmly with your friend.

Explain the actions of the autonomic nervous system. Refer to the description above in

your answer.

(Total 4 marks)

AO1 (2 marks):

• The autonomic nervous system (ANS) controls involuntary bodily functions and has two branches: the sympathetic and parasympathetic nervous systems.

• The sympathetic nervous system prepares the body for fight or flight, while the parasympathetic nervous system helps it return to a calm, resting state (rest and digest).

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AO2 (2 marks):

• When you heard someone running behind you, the sympathetic nervous system was activated — causing your breathing to quicken, heart to pound, and mouth to dry.

• When you realised it was your friend, the parasympathetic nervous system took over, slowing your breathing and helping you feel calm again as you walked home.

Outline the structures and processes involved in synaptic transmission.

(6 marks)

• Synaptic transmission is the process by which one neuron communicates with another across a synapse.

• The electrical impulse (action potential) travels down the axon of the presynaptic neuron.

• When it reaches the axon terminal, it triggers vesicles to release neurotransmitters into the synaptic cleft.

• These neurotransmitters diffuse across the gap and bind to receptor sites on the postsynaptic neuron's membrane.

• This binding can cause excitation or inhibition in the postsynaptic neuron, making it more or less likely to fire.

• Any leftover neurotransmitters are reabsorbed by the presynaptic neuron through reuptake, or broken down by enzymes in the synaptic cleft.

Briefly outline how excitation and inhibition are involved in synaptic transmission (4 marks)

• neurotransmitters can be excitatory or inhibitory

• excitatory neurotransmitters → postsynaptic neuron is more likely to fire an impulse

• inhibitory neurotransmitters → postsynaptic neuron is less likely to fire an impulse

• the excitatory and inhibitory influences are summed → if net effect is IH, neuron is less likely to fire → if net effect is ET, neuron more likely to fire

Describe the divisions of the nervous system. (6 marks)

• nervous system is divided into central and peripheral nervous systems

• cns comprimes of brain and spinal cord

• pns further divided into somatic nervous system ( sensory and motor neurons to carry sensory and motor info to and from cns & also enables reflex actions) and autonomic nervous system ( largely unconsciously)

• ans divided into sympathetic and parasympathetic nervous system

• the sns prepares us for fight or flight

• pns balances the sns providing ‘rest and digest’ functions

Describe the structure and function of a neuron. (6 marks)

• neurons enable communication within the nervous system

• the cell body (soma) contain the genetic material

• branch-like dendrites extend from the cell body

• dendrites carry functional info towards the cell body

• axons carry messages away from the cell body

• terminal boutons at the end of axons, these make synaptic connections with other cells