Paper 2: Topic 6: Biopsychology

Question 1

What are the 5 divisions of the nervous system

Answer 1

1. The Central Nervous System
   • Brain (centre of conscious awareness) & Spinal Cord (reflex actions)
   • Coordinates incoming sensory information and sends instructions to other parts of the NS
   • Cerebral cortex comprises grey and white matter
2. The Peripheral Nervous System
   • Network of nerve fibres (axons) that connects parts of the body with the CNS
   • Transmits messages from the CNS to muscles/glands
3. The Somatic System
   • Conscious movement; myelination enables rapid transmission; reflex arc
4. The Autonomic Nervous System
   • Involuntary bodily functions (eg breathing, heartbeat)
   • Transmits information between organs; not as fast (unmyelinated)
5. Sympathetic & Parasympathetic Nervous System
   • Fight or flight (sympathetic) and rest & digest (parasympathetic)

Question 2

What’s the nervous system

Answer 2

The body’s main communication system which is very fast acting.
• It is a complex network of specialised nerve cells (neurons) which pass information around the body using electrical signals and chemicals (neurotransmitters).

Question 3

What are the 2 divisions of the human nervous system

Answer 3

The central nervous system
The peripheral nervous system

Question 4

What’s the 2 subdivisions of the peripheral nervous system

Answer 4

The autonomic nervous system
The somatic system

Question 5

What’s the 2 subdivisions of the autonomic nervous system

Answer 5

Sympathies division
Parasympathetic division

Question 6

What’s the central nervous system

Answer 6

Brain - centre of conscious awareness
Spinal cord - reflex actions

Question 7

Function of the central nervous system

Answer 7

-Coordinates incoming sensory information and sends instructions to other parts of the NS.
-This is our store of knowledge and habits.

Question 8

Structure of the central nervous system

Answer 8

Made up of the brain and spinal cord
• The brain is the centre of conscious awareness
• The cerebral cortex (3mm outer layer) is highly developed in humans and distinguishes our higher mental functions from other animals
• The spinal cord is an extension of the brain. It is responsible for reflex actions

Question 9

Describe the cerebral cortex of the central nervous system

Answer 9

Outer layer of the brain
Cerebral cortex is also known as grey matter due to the colour of it.
Grey matter is made up of cell bodies.
The white matter is made up of axons which form fibre tracts

Question 10

Structure of the peripheral nervous system

Answer 10

-made up of a Network of nerve fibres (axons) which are connected to the CNS
-it sends info to the CNS from the outside world and transmits messages from the CNS to muscles and glands (effectors) in the body

Question 11

Describe the somatic nervous system of the peripheral nervous system

Answer 11

-controls conscious movement as it sends instructions from CNS to effectors in muscles and glands
-transmits info from receptor cells in sense organs to the CNS (takes info from external environ.)
-needs to act quickly as it’s made up of myelinated neurons

Question 12

Describe the reflex arc of the somatic nervous system

Answer 12

1) stimulus detection: sensory receptor detects a stimulus
2) sensory neuron activation: The sensory receptor sends an electrical impulse along a sensory neuron towards the central nervous system (CNS), typically the spinal cord.
3) relay neuron: In the spinal cord, the action potential reaches an integration centre (usually a synapse) between the sensory neuron and a motor neuron or an interneuron, which then relays the signal.
4) motor neuron activation: The impulse is transmitted to a motor neuron. The motor neuron carries the signal away from the CNS to an effector.
5) effector response: The effector, which is usually a muscle or gland, produces a response. For instance, in the hot object scenario, the effector would be the muscles in your arm, causing you to withdraw your hand quickly

Question 13

Describe the pathway of the somatic nervous system

Answer 13

Stimulus -> sensory neuron -> relay neuron -> motor neuron -> effector (muscle/gland)

Question 14

Function of the autonomic nervous system

Answer 14

-controls involuntary boldly functions which aren’t consciously directed eg: breathing, heartbeat, digestive processes and sexual arousal
-only transmits info to and from internal bodily organs (don’t need sensory pathways)
-acts more slowly than the SNS (somatic) and therefore made of unmyleinated nerve fibres
- divided into sympathetic and parasympathetic nervous system

Question 15

Describe the sympathetic divisions of the autonomic nervous system

Answer 15

works with the endocrine system (comprising glands & hormones) to get the body prepared for fight or flight

Question 16

Describe the parasympathetic divisions of the autonomic nervous system

Answer 16

works with the endocrine system to return the body to its normal resting state (rest and digest).

Question 17

Brief:
What does the PNS system consist of and function

Answer 17

Network of nerve fibres

Connects parts of the body with CNS

Question 18

Brief:
What does the ANS system consist of and function

Answer 18

Network of unmyelinated nerve fibres (slower acting)

Controls the automatic functions of the body e.g. breathing, heart rate Connects the senses and the organs with the CNS
Concerned with emotions, threats and bodily changes

Question 19

Brief:
What does the SNS system consist of and function

Answer 19

Network of myelinated sensory and motor neurons (quicker acting)

Controls the conscious movement e.g. reflex of touching a hot pan
Carries sensory information from the outside world and internal organs to the CNS (sensory neurons)
Carries instructions for movement from the CNS (motor neurons)

Question 20

What’s the function of the spinal cord

Answer 20

Responsible for reflex actions
Ensures signals from the brain are transmitted to the rest of the body through the Peritheral nervous system

Question 21

2: Structure and functions of neurons

What is a neuron?

Answer 21

Specialised nerve cells which are part of the nervous system
80% of neurons are located in the brain and 20% are in the spinal cord, peripheral nervous system, and the gut (gut brain axis)

Question 22

2: Structure and functions of neurons

How do neurons transmit info?

Answer 22

electrically (through action potentials)
chemically (using neurotransmitters)

Question 23

2: Structure and functions of neurons

What do all neurons consist of?

Answer 23

Cell body, dendrites, mylien sheath, axon, nodes of ranvier
Dendrites receive signals; action potentials propagate the signal down the axon to the axon terminal, stimulating the release of neurotransmitters

Question 24

2: Structure and functions of neurons

What are dendrites and what do they do?

Answer 24

Dendirtes protrude (stick out) from the cell body, these carry nerve impulses (action potentials) from neighbouring neurons towards the cell body

Question 25

2: Structure and functions of neurons

What is the function of the cell body?

Answer 25

Includes a nucleus which contains the genetic material of the cell
Also called the Soma

Question 26

2: Structure and functions of neurons

What is the axon?

Answer 26

Carries action potential away from the cell body down the length of the neuron. It’s covered in a myelin sheath that protects the axon and speeds up electrical transmission of the action potential

Question 27

2: Structure and functions of neurons

What is the axon terminal and myelin sheith

Answer 27

Protrude from the axon and form synapses with the dendrites of the neighbouring neuron

Covers the axon, protects the axon and speeds up electrical transmission of the impulse
It’s segmented by gaps called nodes of ranvier which speed up the transmission by forcing it to ‘jump’ across the gaps along the axon

Question 28

2: Structure and functions of neurons

What disease results from degeneration of the myelin sheath?

Answer 28

Multiple Sclerosis. A chromic autoimmune disorder where the immune system attacks the myelin sheath in the CNS, including the brain and spinal cord, causing slowing of neurotransmissiom, resulting in symptoms like fatigue, numbness, weakness, vision problems, difficulty with coordination and balance and cognitive issues

Question 29

2: Structure and functions of neurons

Describe the neuron pathway

Answer 29

Stimulus -> sensory neurons -> relay neurons (in brain) -> motor neuron -> response
Sensory input -> integration -> motor output

Question 30

2: Structure and functions of neurons

What size dendrites and axons do sensory neurons have?

Answer 30

Sensory neuron – afferent (incoming to the brain) neurons

Long dendirtes and short axons. Cell Body is in the middle of the spinal cord.

Question 31

2: Structure and functions of neurons

Function of sensory neuron

Answer 31

Take sensory information from the environment (pocked with a needle) and sends signals to the brain and convert a specific type of stimulus by their receptors into action potentials

Question 32

2: Structure and functions of neurons

Do all messages go to the brain from sensory neurons

Answer 32

No. Some end in the spinal cord to allow reflex actions to occur quickly without the delay of sending impulses to the brain

Question 33

2: Structure and functions of neurons

What size dendrites and axons do motor neurons have?

Answer 33

Efferent (outgoing) neurons

Short dendrites: connect to axons of relay neurons
Long axons: to connect to effector organs

Question 34

2: Structure and functions of neurons

Function of motor neurons

Answer 34

Take messages from the CNS to effectors like glands and muscles

Question 35

2: Structure and functions of neurons

Where is its cell body and axon located in motor neurons?

Answer 35

n the spinal cord
Fibre (axon) projects outside the spinal cord to directly or indirectly control effector organs

Question 36

2: Structure and functions of neurons

What size dendrites and axons do relay neurons have?

Answer 36

Interneuron Neurons

Short dendrites and short axons – as they don’t have to span long distances and aren’t myelinated

Question 37

2: Structure and functions of neurons

What is the function of relay neurons

Answer 37

Connect sensory neurons to the motor or other relay neurons
Allow motor neurons and sensory neurons to communicate with eachother
Found only in the brain and spinal cord. Make up 97% of all neurons

Question 38

2: Structure and functions of neurons

Give an example of when relay neurons are used in the reflex arc

Answer 38

Patellar reflex

Reflex arc:
1) Stimulus detection: sensory receptor detects a stimulus
2) Sensory neuron activation:
3) Relay neuron:
4) Motor neuron activation:
5) Effector response:

Question 39

2: Structure and functions of neurons

Describe the human connectors project

Answer 39

Sensory receptors synapses with inter neuron in spinal cord. Inter neuron synapse with motor neuron which causes contract in quadriceps so leg move

Question 40

2: Structure and functions of neurons

Define the nodes of ranvier

Answer 40

Gaps between the myelin sheath which speed up transmission by making by action potential ‘jump’ across the gaps along the axon

Question 41

3: synaptic transmission

What is the process of synaptic transmission?

Answer 41

one neuron communicates with another by releasing neurotransmitters to diffuse across the synapse

Electrochemical transmission of nerve impulses through infra-neuronal propagation of action potentials and inter-neurornal release of neurotransmitters that bind to post-synaptic receptors, affecting the electric charge of the post-synaptic neuron and prosperity to fire and an action potential

Question 42

3: synaptic transmission

Explain what the synapse is.

Answer 42

The gap between the presynaptic neurons axon terminal and the post synpaic neurons dendrites/cell body where neuronal communication continues via release/uptake of neurotransmitters that diffuses across the gap

Question 43

3: synaptic transmission

How does a neurotransmitter work?

Answer 43

How neurons communicate chemically
1) The electrical signal arrives at the axon terminal of the presynaptic neuron, the neurotransmitter to be released over supposed
2) Neurotransmitters bind to completely Receptors on the post synaptic neuron
3) This activation of the receptor determines whether the post-synaptic neuron will generate an alectrical signal

Question 44

3: synaptic transmission

Explain how an action potential works
(Electrical impulse)

Answer 44

When a neuron is in a resting state, it’s negatively charged compared to the outside

When a neuron is activated by a stimulus, if this causes to become more positively charged it caused an action potential to travel down the axon

Question 45

3: synaptic transmission

How does an action potential cause release of a neurotransmitter?

Answer 45

1) Action potential travels along the axon to the axon terminal of the presynaptic neuron
2) This triggers the vesicles to migrate towards and bind to the presynaptic memebrane and release neurostamnsitters
3) Neurotransmitters diffuse across the synapse and bind with the post synpaic receptors like a lock and key

Question 46

3: synaptic transmission

Name 4 neurotransmitters

Answer 46

Adrenaline – right or flight
GABA – claiming, reduces anxiety (links to benzodiazepines for treating OCD) – inhibitory
Noradrenaline – concentration
Dopamine – pleasure

Question 47

3: synaptic transmission

Explain how excitation works, and what is an EPSP?

Answer 47

Excitatory effects facilitate the firing of action potentials, promoting alertness and activity, if a neurotransmitter is excitatory , it leads to the generation of a excitatory postsynaptic potential (EPSP) leading to a positive charge at the postsynaptic membrane.
Makes the inside of the postsynaptic neuron less negitive compared to outside, moving the membrane potential closer to the threshold needed to trigger an action potmetial.
It’s more likely that the neuron will fire an action potential.

Question 48

3: synaptic transmission

Explain how inhibition works, and what is an IPSP?

Answer 48

help to calm the mind and body and involved in inducing sleep.
When a neurotransmitter caused an inhibitory effect, it leads to the generation of an inhibitory postsynaptic potential (IPSP) leading to a negitive charge at the postsynaptic membrane.
Makes the inside of the postsynaptic neuron more negitive compared to the outside, moving the membrane potential further away form the threshold needed to trigger an action potential.
Making it less likely that the neuron will fire an action potential .

Question 49

3: synaptic transmission

Explain temporal summation and spatial summation

Answer 49

Temporal: the combined effects of inputs over time
Spatial: the combined effects of inputs across multiple neurons

Summation:
A nerve cell can receive both EPSP and IPSPs at the same time
Summation is the net sum of the total IPSPs and EPSPs which determines whether or not the cell fires. The threshold is -60v for an action potential to be created.

Question 50

4: endocrine system

What is the endocrine system?

Answer 50

A communication system that instructs glands to release hormones directly into the bloodstream which carry the hormones to the target organs (effectors). It works along side the NS to control vital bodily functions.

Question 51

4: endocrine system

What speed does the endocrine system pass messages compared to the nervous system?

Answer 51

It acts slower than the NS but still has powerful effects

Question 52

4: endocrine system

What is a hormone?

Answer 52

A chemical substance that circulates the bloodstream and affects target organs. Produced in large quantities.
They have a slower release but longer action than neurotransmitters

Question 53

4: endocrine system

Label the diagram on the Cornell notes of the glands

Answer 53

.

Question 54

4: endocrine system

What does the hypothalamus do?

Answer 54

Brain region connected to the pituitary gland.
Responsible for stimulating or controlling the release of hormones from the pituitary gland.
It’s the control system which regulates the endocrine system

Question 55

4: endocrine system

What effects do hormones have?

Answer 55

Finish this.

Question 56

4: endocrine system

What are the 2 adrenal gland regions?

Answer 56

-adrenal cortex (outside)
-adrenal medulla (inside)

Question 57

4: endocrine system
What is released from the adrenal medulla gland and what impact does it have:

Answer 57

Secretes adrenaline and noradrenaline for the fight or flight response

Question 58

4: endocrine system

What is released from the testes glands and what impact does it have:

Answer 58

Secretes testosterone which is responsible for the male sex charectaristics during puberty and muscle growth

Question 59

4: endocrine system

What is released from the adrenal cortex glands and what impact does it have:

Answer 59

Secretes cortisol which stimulates the release of glucose to provide the body with energy whilst suppressing the immune system

Question 60

4: endocrine system

What is released from the ovaries glands and what impact does it have:

Answer 60

Secretes oestrogen which regulates female reproductive system including menstral cycle and pregnancy

Question 61

4: endocrine system

What is released from the pineal glands and what impact does it have:

Answer 61

Secretes melatonin which regulates sleep-wake cycle

Question 62

4: endocrine system

What is released from the pituitary gland and what impact does it have:

Answer 62

Secretes Growth hormone, prolactin, ACTH, TSH, FSH, ADH, oxytocin
(The majority of hormones abreviated into capital letters are secreted by the pituary gland)
It’s the master gland that regulates other endocrine glands, controls growth, lactation, stress response (ACTH) and water balance (ADH)

Question 63

5: fight or flight response

What is a gland?

Answer 63

Specialised organ that produces and secretes hormones, enzymes and fluids into the bloodstream

Question 64

5: fight or flight response

What is a hormone?

Answer 64

A chemical messenger produced by glands that regulates various physiological processes in the body by affecting target cells or organs

Question 65

5: fight or flight response

Name 8 major endocrine glands

Answer 65

Hypothalamus – part of CNS – connects to pituatory gland (the master gland)
Thyroid – metabolism
Testes – testostrione
Ovaries – oestorgen and progesterone
Adrenal glands – fight and flight
Pancreas – controls blood sugar

Question 66

5: fight or flight response

Which two biological systems combine to implement the fight or flight response?

Answer 66

Endocrine system and nervous system, necessary to sustain arousal

Question 67

5: fight or flight response

What phrase is used when talking about fight or flight?

Answer 67

‘Make the body prepared’
A sequence of activities within the body that are triggered when the body prepares itself for defending or attacking (fight) or running away to safety (flight)

Question 68

5: fight or flight response

What’s the evolutionary origin of the fight or flight response

Answer 68

It’s our engrained survival instinct And represents the options our ancient ancestors could choose when dealing with dangerous environments

Question 69

5: fight or flight response

Which brain region is involved in sensing danger, and what is the name of the pathway which is activated by it?

Answer 69

Amygdala
It’s assossiated with emotional processes and is the body’s ‘threat’ sensor
Part of the limbic system
If it alerts that there’s a threat then it will activate a sequence of events (the sympathomedullary (SAM) pathway)

Question 70

5: fight or flight response

What are the steps of the activation of the SAM pathway?

Answer 70

Amygdala activates the SAM pathway -> Hypothalamus activates -> sympathetic nervous system triggers -> adrenal medulla ->releases/secretes adrenaline and noradrenaline facilitates -> fight or flight response

Question 71

5: fight or flight response

In detail, what are the steps of the activation of the SAM pathway

Answer 71

1) The amygdala sends distress signals to the hypothalamus which activates the sympathetic branch of the autonomic nervous system (ANS)
- The ANS changes from resting state (parasympathetic) to the physiologically aroused (sympathetic)
2) This triggers the adrenal medulla to relase the stress hormone adrenaline into the blood stream
- Adrenaline triggers physiological changes in the body eg: increases heart rate which prepares the body for the fight or flight response
3) One the threat has passed the parasympathetic NS return sbody to its resting state and bodily functions (rest and digest). The parasympathetic NS and sympathetic NS work as an antagonistic pair; when one is activates the other isn’t. Eg: Heart rate and blood pressure return to resting level and pupils constrict, bladder control is regained and liver stored glucose in the form of glycogen for future use

Question 72

5: fight or flight response

List 5 effects of the role of adrenaline

Answer 72

increase your heart rate: pushing blood to the muscles to enable action and to the brain to facilitate rapid response planning to prepare the body for action
-pupillary dilation: allows more light into eyes and to increase awareness of visual information to prepare the body for action
-breathing becomes more rapid to take in more oxygen to provide to the muscles to aid movement to prepare the body for action
-blood sugar (glucose) and fats are released into the bloodstream to provide energy to provide the body for action
-diversion of blood away from the digestive system to conserve energy by constricting blood vessels to provide the body for action
-increase in sweating: to cool your body

Question 73

5: fight or flight response

Describe the involvement of the HPA Axis in the stress response

Answer 73

1) Detection of stress: when encountering a stressor (physical, emotional or psychological) the hypothalamus senses this and activated the HPA axis
2) Release of CRH: hypothalamus scope creates cortiotropin-releasing hormone (CRH) Into the blood, which travels to the pituitary gland
3) Release of ACTH: in response to CRH, the pituatory gland releases adrenocortiotropic hormone (ACTH) into the blood stream
4) Stimulation of the Adrenal glands: ACTH reaches the adrenal glands and stimulates the adrenal cortex to produce and release the hormone cortisol
5) Effects of cortisol: cortisol helps mobilise energy by increasing glucose in the bloodstream, enhancing brains use of glucose and increasing availability of substances that repairs tissue. It curbs functions thay would be nonessential in the fight ornfligh situation eg: growth, reproduction, digestion
6) Short term and long term effects: ST – enables te body to repsond to threats, but chronic activation can lead to impaired cognition and immunity and has been linked to anxiety, depression and weight gain

Question 74

5: fight or flight response

Compare the HPA axis and the SAM pathway

Answer 74

HPA axis is activated more slowly (minutes to hours)m releasing cortisol
SAM pathway provides a more rapid and immediate response, releasing adrenaline

HPA Axis: cortisol hormone
SAM pathway: adrenaline hormone

Question 75

8/16 marker hasn’t come up before:

5: fight or flight response

3 limitations of the Fight or flight response

Answer 75

P: negitive consequences on the body in todays modern world
Eg: stressors of modern life don’t generally need such a physical reaction that gives us energy to fight or flight as they’re more psychological and longer term
Ex: the problem for modern humans arises when the stress response is repeatedly activated. This increases levels of cortisol which in small amounts is good but too much of it suppresses the immune system
L: it’s not always helpful in todays modern world. By learning coping strategies like breathing techniques people can learn how to activate the parasympathetic NS and reduce these negitive consequences

: gender differences in the acute stress response which are ignores and presents a beta bias
Eg: Taylor suggests females may display a different patterns to males. She argues that females protect themselves and their young through nurturing behaviours (tending) and forming protective alliances with other women (befriending)
Ex: women may have a completely different system to coping with stress because their responses evolved in the context of being the primary caregiver of their children. Fleeing too readily would put their offspring at risk
L: so the theory many minimise the differnce between male and females

incomplete explaination
Eg: Gray argues that the first phase of reaction to a threat is not to fight or flee but to avoid confrontation. He suggests that prior to responding with attacking or running away, most animals typically display the ‘freeze’ response to ‘stop, look and listen’ response.
Ex: adaptive advantages of this for humans is that ‘freezing’ focuses attention and makes them look for new info in order to make the best response to the threat.
L: this suggests that the original theory is only a partial explaination to how danger reacts to immediate short term danger

Question 76

6: localisation of function

What does localization of function mean?

Answer 76

The concept of Functions including movement, speech and memory are performed in/ specific to distinct regions of the brain (localised)
This includes the motor cortex, somatosensory cortex, auditory cortex and visual cortex
For example, Broca’s area is specific to language production.

Question 77

6: localisation of function

How does localisation of function contrast to a holistic view?

Answer 77

It suggests all parts of the brain are involved in the processing of thought and action
Before scientific study of the brain, it was generally believed that the brain worked holistically i.e. all parts together for all functions
Nowadays the brain is seen as more locialised for specific functions

Question 78

6: localisation of function
What is the outer layer of the brain / both hemispheres called?

Answer 78

Cerebral cortex (grey matter)
3mm thick

Grey – Cell bodies and dendirtes

Question 79

6: localisation of function

What are gyri and sulci?

Answer 79

On cerebral cortex:
Gyri – outer folds
Saulci – inner folds

Increases surface area to volume ratio

Question 80

6: localisation of function

What is the hemispheric lateralisation of function?

Answer 80

concept that different hemispheres in the brain have differing functions. For example, the language functions are typically lateralised to the left hemisphere of the brain.

Lateralisation: some of our physical and psychological functions are controlled or dominated by a particular hemisphere.
Left and right hemispheres are separated

Contralateral control: right hemispheres activity including motor cortex controls left side, left hemispheres activity including motor cortex controls right

Question 81

6: localisation of function

What are the 4 lobes of the brain called?

Answer 81

Frontal lobe – persona
Parietal lobe – sensory perception and awareness
Occipital lobe – vision
Temporal lobe – auditory, speech, Broca’s area
Cerebellum – movement, breathing, unconscious actions

Frontal lobe and parietal lobe is seperated by central salcus
Central salcus- separates motor cortex and somatosensory cortex
Everything on motor cortex side is frontal lobe side
Somatosensory cortex is on parental love side

Question 82

6: localisation of function

What is the role of the limbic system?

Answer 82

Midbrain, unique to only mammals
Includes: Thalamus, Striatum, Amygdala
MacLean – suggests it’s centre of emotion and learning

Question 83

6: localisation of function

Who were 2 neurosurgeons known for identifying areas of the brain associated with speech processing?

Answer 83

Broca:
Identified a small area in the left posterior frontal lobe for speech production. Lesions in this area causes Brocas aphasia which is chaarectarised by speech that’s slow, laborious and lacking in fluency
Inferior frontal gyrus

Wernicke:
Studied patients with severe difficulties in understanding language but no problems speaking and producing it.
He identified an area in the left posterior temporal lobe as being responsible for speech comprehension – Wernickes area
Patients with Wernickes aphasia often produce nonsense words eg: word salad

Question 84

6: localisation of function

What is Broca’s aphasia, and how is it caused?

Answer 84

Studied patient named Tan and eight other post mortems who had speech production issues and lesions in their left frontal hemisphere
Led Broca to identify the existence of a language centre for speech production in the posterior portion of the frontal lobe of the left hemisphere (Brocas area)
Those with it stuggle with speech production

Question 85

6: localisation of function

What is Wenicke’s aphasia, and how is it caused?

Answer 85

Studied a patient who suffered a stroke and could not understand language. He studied his brain post-mortem
Led Wernickesto identify that the area of the brain involved in understanding language was in the posterior portion of the left temporal lobe (Wernickes area)
Those with it stuggle with speech comprehension

Question 86

6: localisation of function

How is the case of Phineas Gage seen as evidence for the localisation of function?

Answer 86

1848 Railroad
25 years old
Iron pole went through his gages left check through his left eye and exciting his skull and loosing most of his left frontal lobe
Survived but severe personality changes from calm to quick-tempered and rude
Change in temperament suggests the frontal lobe may be responsible for regulating mood
Case study - can’t extrapolate

Question 87

6: localisation of function

What is the role of the frontal lobe

Answer 87

Where the motor area is located, it’s responsible for voluntary movements by sending signals to muscle in the body and personality eg: Phineas Gage

Question 88

6: localisation of function

What’s the role of the parietal lobe

Answer 88

Receives sensory information from the skin to produce sensations related to pressure pain, temperature, etc. different parts of the somatosensory area receives messages from different locations of the body

Question 89

6: localisation of function

What’s the role of the occipital lobe

Answer 89

At the back of the brain, where the visual area is located. contains different parts that process different types of information including colour, shape or movement.

Question 90

6: localisation of function

What’s the role of the temporal lobe

Answer 90

Where the auditory area is located (Superior temporal gyrus – upper temporal outer lobe). Responsible for analysing and processing acoustic info. The auditory area contains different parts, and the primary auditory area is involved processing simple features of sound including loudness, tempo and pitch.

Question 91

6: localisation of function

What’s the role of the left frontal lobe

Answer 91

Where Broca’s area is found in the left frontal lobe and is thought to be involved in fluent language production

Question 92

6: localisation of function

What’s the role of the left temporal love

Answer 92

Where Wernickes area is found In the left temporal lobe and is thought to be involved in language comprehension

Question 93

6: localisation of function

How is the spatial arrangement of the motor cortex linked to its function?

Answer 93

Role of the motor area is to control volentrary motor movement by sending signals to muscles in the body
It also controls muscles on the opposite side of the body, eg: left hemisphere controls muscle movement on the right, vise versa.
Regions of the motor area are arranged in a logical order, eg: region controlling finger movement is located next to the region that controls the hand

Question 94

6: localisation of function

Strengths of localisation of function

Answer 94

P: lots of evidence from brain scans which provides support that neurological functions are localised
Eg: Tulving revealed that semantic and episodic memories red side in different parts of the prefrontal cortex with semantic memories in the left hemisphere and episodic in the right.
Peterson revealed how Wernickes area was active during a listening task and Broca’s area during a reading task.
Ex: both of these studies show the different areas of the brain are active during different cognitive functions, demonstrating a localisation of function
Modern imaging methods also indentified the functional connectivity of spatially distributed brain circuits, rather than individual brain regions, to be involved in the
Performance of cognitive function Suggesting that functional localisation Invoves brain circuits not just isolated regions
L: Increases validity as it supports idea that Different brain regions carry out different functions.

P: evidence from case studies from patients with brain damage that helped develop our understanding
Eg: patient HM who had experimental surgery which removed his hippocampus following epileptic seizures after an accident. After the hippocampus was removed, he was no longer able to transfer episodic episodic and semantic memories from his STM to his LTM but was able to learn new procedural tasks eg: mirror drawing task
Ex: this shows that the hippocampus has a role in formation of new LTM memories,
Expect procedural memories which are assossiated with the motor cortex and the cerebellum and basil ganglia
L: case studies like HM and Broca’s ‘patient Tan’who could only produce a single syllable after lesions in his Broca’s area , provides researchers with an in-depth understanding of the role of certain Regions in the brain and increases the validity of the theory

Question 95

6: localisation of function

Limitation of localisation of functions

Answer 95

P: critised by researchers who argue that the brain works more holistically
Eg: Lashleys theory known as the principle of equipotentially, suggets that basic motor and sensory functions are local sided but that higher mental functions aren’t. The removal of 10-50% of cortex in rats; no area more important than others. He claimed that interact areas of the cortex could take over a responsibility for specific cognitive functions following an injury
Ex: He argues that localisation is biologically reductionist as it tries to reduce very complex human behaviours and cognitive processes to one specific brain region.
Arguin that more holistic understanding of the brain is truly required to understand complex cognitive processes like language. Modern imaging methods have focused on the functional connectivity between regions, and have emphasised the role of more distributed brain circuits eg: limbic system or fro to-striatal system, rather than specific brain regions

P: failure to consider individual differences
Eg: Harasty et al. found larger languages Broca’s Areas and Wernickes areas in females than males, which might explain women’s greater ease with language. This introduces beta bias as the theory overlooks gender differences and doesn’t account for variations of brain regions size and activity between men and women, leading to proportionally inaccurate generalisations
Ex: individual differences also include age related changes in brain function and plasticity. These differences are crucial for developing effective treatments for neurological conditions. Ignoring them can result in less effective interventions
L: generalising research on localisation of function to both gnenders without caution of their differences is problematic. Future research should include diverse samples to understand how individual differences affect brain function, ensuring theories are taileired to various individuals charectarisitcs, enhancing effectivenessr

Question 96

7: hemispheric lateralisation

What does hemispheric laterlisation mean?

Answer 96

Concept that the 2 different hemispheres (halves) in the brain have differing functions. Eg: the language functions are typically lateralised to the left hemisphere of the brain. Certain mental process and behaviours are mainly controlled by one hemisphere rather than another
The divisions of functions between two hemispheres .

Question 97

7: hemispheric lateralisation

What is the difference between localisation and lateralisation?

Answer 97

Hemispheric lateralisation is specific to functions in the 2 hemispheres whereas localisation of function is about specific regions of the brain controlling specific functions

Question 98

7: hemispheric lateralisation

Which hemisphere processes the left visual field

Answer 98

The right hemisphere
The brain is comtralateral- left side controls right visa versa

Question 99

7: hemispheric lateralisation

Which hemisphere processes the right visual field?

Answer 99

Left

Question 100

7: hemispheric lateralisation

Where does the left visual field project to on the retina?

Answer 100

Nasal retina
Cro Left eye: nasal retina
Right eye: temporal retima

Right side of the. Rain process info from left side of bod (eg: visual info from the left visual field) yet both eyes process it

Question 101

7: hemispheric lateralisation

Which part of the retina sends information to the contralateral hemisphere?

Where does this occur?

Answer 101

Info from Nasal retima crosses to comtralateral hemisphere at the optic chiasm

Question 102

7: hemispheric lateralisation

Which part of the retina does not send information to the contralateral hemisphere, and where is it sent?

Answer 102

Temporal retina
So remains in the ipsilateral hemisphere

Question 103

7: hemispheric lateralisation

At which point is the visual information combined, and which structure is involved?

Question 104

7: hemispheric lateralisation

Where does the right visual field project information to?

Answer 104

Right eye: nasal retina
Left eye: temporal retina

Question 105

7: hemispheric lateralisation

What happens to visual information if the corpus callosum is severed?

Answer 105

Info arriving at the cortex can’t be exchanged between hemispheres
Each hemisphere will only be aware of the contralateral info

Question 106

7: hemispheric lateralisation

Which hemisphere is language largely processed in?

Answer 106

Left
Where Broca’s area and Wernickes area are located
Broca – speech production
Wernicke – speech processing and comprehension

Question 107

7: hemispheric lateralisation

Which hemisphere are faces and facial emotion processed in?

Answer 107

Right
Right doesn’t have verbal language

Question 108

7: hemispheric lateralisation

Who conducted experiments on split-brain patients?

Answer 108

Sperry

Question 109

7: hemispheric lateralisation

Define split brain research

Answer 109

serious of studies on people who habe 2 separated hemispheres of their brain. This occurred because of serious epilepsy, epileptic patients who had experienced a surgical separation of the hemispheres at the corpus callosum (a commissurotomy) This allowed researchers to investigate the extent to which brain function is lateralised as the electrical discharge of epilepsy can’t move across to the whole brain

Question 110

7: hemispheric lateralisation

What was Sperry’s experiment?

Answer 110

He realised that the split brain patent d who had undergone a commissurotomy
Could be studied to independently
Procedure: the divide field method. Ppts look ahead at the dot in the centre of the screen and see one item to the left (of their visual field) and one item to the right (of their visual field) for 0.2 secs

Question 111

7: hemispheric lateralisation

Why was the visual stimulus presented so briefly?

Answer 111

So it only appears in one hemisphere To prevent subjects from moving their eyes, and thus transferring information between the visual fields

Question 112

7: hemispheric lateralisation

What happened when visual information was presented to the right visual field and why?

Answer 112

Processed by the left hemisphere
The left hemisphere is dominant for verbal processing, the patients answer matches the word

Question 113

7: hemispheric lateralisation

What would happen when visual information was presented to the left visual field, and why?

Answer 113

The right hemisphere can’t share info with the left, so late it is unable to say what he saw, but can draw it

Question 114

7: hemispheric lateralisation

What happened when participants were asked to recognise objects presented to the left visual field by touch

Answer 114

Object in right hand:
Processed by left hemisphere
Could describe wha they felt, could identify the object by selecting similar object from a series of objects

Object in left hand:
Processed by right hemisphere
Couldn’t describe what they felt, so made guesses
But left hand could identify a test object, by selecting a similar object from a series of a objects

Question 115

7: hemispheric lateralisation

What happened when composite faces (composed of a female and a male face), and why?

Answer 115

Picture presented to right visual field:
Processed by left hemisphere
While right hand would attempt to draw a picture, it wasn’t as clear as left hand picture as right hemisphere is dominant for visual motor tasks
Picture presented to left visual field:
Left hand (controlled by right hemisphere) would consistently draw clearer and better pictures than the right hand (even though all ppts were right-handed)

Question 116

7: hemispheric lateralisation

What do we conclude from work on split-brain patients?

Answer 116

The findings of Sperry and Gazzaniga’s research highlights a number of key differences between the two hemispheres.
• Firstly, the left hemisphere is dominant in terms of speech and language.
• Secondly, the right hemisphere is dominant in terms of visual-motor tasks

Question 117

7: hemispheric lateralisation

Strength and 2 limitations

Answer 117

P: research to support the understanding of hemispheric specialisation
Eg: Luck et al. (1989) showed that split-brain participants are faster than normal controls at identifying the odd one out in an array of similar objects, highlighting the
specialised processing abilities of the hemispheres. Kingstone et al. (1995) suggest that in the normal brain, the superior processing abilities of the left hemisphere are ‘watered down’ by the inferior right hemisphere.
These findings align with Sperry’s earlier conclusions, reinforcing the idea that the left and right hemispheres have distinct functions and abilities.
This supports Sperry’s earlier findings, demonstrating the robustness of the concept that the ‘left brain’ and ‘right brain’ are distinct in terms of functions and abilities.

Limit: Sperry’s research on split-brain patients is the methodological challenges that may impact the generalizability and internal validity of the findings.
The study was a quasi-experiment, so participants were not randomly assigned to groups, introducing potential bias. Only individuals with epilepsy severe enough to warrant surgery were included in the experimental group, while the control group consisted of individuals without epilepsy, making epilepsy a potential confounding variable. Furthermore, the small sample size of 11 patients, all of whom had epilepsy, raises concerns about population validity.
These factors make it difficult to generalize the findings, as the unique characteristics of these patients could limit the
applicability of the results to a broader population.
Therefore, the study design and the specific characteristics of the participants may reduce the generalizability of Sperry’s conclusions to the general population.

Limit:
P: limitation of the split-brain research is that findings from challenge the earlier conclusions of split-brain
research, particularly regarding the lateralization of language in the brain.
Initially, split-brain research suggested that the right hemisphere
was incapable of handling even basic language functions. However, E more recent case studies, such as that of patient J.W., demonstrate
otherwise. J.W. developed the ability to speak using the right hemisphere, enabling him to verbally express information presented to either the left or the right hemisphere.
This case illustrates the brain’s remarkable ability to adapt following damage, suggesting that language may not be exclusively localized to the left hemisphere as previously thought. The adaptability of J.W.’s brain challenges the oversimplified view of hemispheric lateralization proposed by early split-brain research, highlighting the complexity of brain functions and the potential for neural plasticity.
Therefore, Gazzaniga’s findings call into question the validity of earlier research on hemispheric lateralization, suggesting that the brain’s language capabilities may be more flexible and less localized than initially believed. This emphasizes the need for continued research to fully understand the intricacies of brain function following damage.

Question 118

8. Plasticity and functional recovery

Define plasticity

Answer 118

Brains ability to change and adapt over time as a result of experience and learning

Question 119

8. Plasticity and functional recovery

How the view on brain plasticity has changed

Answer 119

Research has demonstrated that the brain continues to create new neural pathways and alter existing ones in response to changing experiences
Before it was thought that vhs he’s were restricted to the developing brain within childhood and the adult brain has moved beyond a critical period would remain fixed and static in terms of function and structure

Question 120

8. Plasticity and functional recovery

Effects of aging:
How does infant development demonstrate plasticity?

How does this relate to the adult brain?

Answer 120

In infancy: brain experiences growth in the number of synaptic connections it has; peaking around 15,000 per neuron at age 2-3. Twice as many as in the adult
As we age, connections that are rarely used are deleted and frequently used connections are strengthened- synaptic pruning

More stimulations = more synaptic connections = more dense the synapses

Question 121

8. Plasticity and functional recovery

What is functional recovery?

Answer 121

Form of neural plasticity where following damage from trauma the brain is able to redistribute functions normally performed by damaged areas to other undamaged areas
Eg: Romanian orphans

Question 122

8. Plasticity and functional recovery

Give 4 examples of how when environments are enriched or impoverished, it is reflected in brain plasticity

Answer 122

1) Davidson found Tibetan monks had increases gamma waves (coordinate neural activity when meditating. Shows LT effects
2) Rosenweig brains of enriched rats were different from the impoverished rats, the neurons were larger, the cerebral cortex heavier and thicker
3) Boyke found there’s a natural decline in cognitive function with age. Boyke found 60 year olds had increased grey matter in the visual cortex when learning to juggle. It’s decreased when they stopped
4) Therapy

Question 123

8. Plasticity and functional recovery

Explain Maguire’s (2000) study: what was the aim, method, results?

Answer 123

Studied the brains in London taxi drivers and found significantly more volume of grey matter in the posterior hippocampus than in a matched control group.
This part of the brain is associated with the development of spacial and navigation skills in humans and animals

London cab drivers must take a test called ‘the Knowledge’ which assesses their recall of the city streets and possible routes

Maguire used 16 healthy right handed males who were taxi drivers compared to non 50 healthy right handed males who were not taxi drivers. An MRI was used to detect changes in the structure of the brain as a result of experience
The results showed the taxi drivers had larger posterior (back) hippocampus compared to the controls that had a larger anterior hippocampi compared to taxi drivers

Data is only correlational

Question 124

8. Plasticity and functional recovery

What might be an alternative explanation?
What does the research imply?

Question 125

8. Plasticity and functional recovery

Name 2 other studies that are consistent with the findings of Maguire.

Answer 125

Draganksi – imaged brains of medical students 3 months before and after their final exams. Learning-induced changes were seen to have occurred in the posterior hippocampus and parietal lobe, presumably as a result of studying for exams
Mechelli – found a larger parietal cortex in the brain of people who were bilingual compared to matched monolingual conditions

Question 126

8. Plasticity and functional recovery

How does functional recovery suggest plasticity?

Question 127

8. Plasticity and functional recovery

How does neural reorganisation support plasticity?

Answer 127

Healthy brains may take over the functions of those areas that are damaged, destroyed or even missing (neural reorganisation)
Neuroscientists suggest that is process can occur quickly after trauma (spontaneous recovery) and then slow down after several weeks or months. At this point the individual may need rehabilitate therapy

Question 128

8. Plasticity and functional recovery

How can neural reorganisation occur?

Answer 128

Recruitment of homologous areas is when a homologous (similar) area of the brain on the opposite side is used to perform a specific task
One example would be Broca’s area was damaged (usually on the left side of the brain) the right side equivalent would carry out the functions (JW case study
After time,

Question 129

8. Plasticity and functional recovery

What is neurogenesis?

Answer 129

Brain is able to retire and reorganise itself by forming new neurons

Question 130

8. Plasticity and functional recovery

How might secondary neural pathways be involved in functional recovery?

Answer 130

The brain doing neurogenesis and forming new synaptic connections close to the area of damage. Secondary pathways are activated to enable functioning to containers, often in the same ways as before (Doidge 2007)

Question 131

8. Plasticity and functional recovery

Name 3 structural changes related to plasticity.

Answer 131

1) Axonal sprouting: growth of new nerve endings which connects with other undamaged nerve cells to form new neural pathways
2) Reformation of blood vessels
3) Denervation super-sensitivity: axons become more responsive to compensate for the loss of adjacent neurons

Question 132

8. Plasticity and functional recovery

2 strengths

Answer 132

P: empirical support from studies, which provides strong evidence to support that the brain can undergo structural changes in response to environmental demands.
Maguire et al. (2000) used MRI scans on London taxi drivers and found that their posterior hippocampal volume was significantly larger than that of a control group, correlating with the length of time spent as a taxi driver.
This finding supports the concept of neuroplasticity, as it shows that the hippocampus can increase in size due to the demands placed on spatial navigation by the taxi drivers’ profession. The ability of the brain to adapt structurally highlights the plastic nature of neural circuits, reinforcing the idea that experience can directly shape the brain’s architecture.
Therefore, empirical evidence such as this increases the validity of the neuroplasticity theory, demonstrating its practical application and relevance in real-world scenarios.

P: strongly supported by empirical evidence that shows how the brain can change its structure in response to environmental stimuli.
Rosenzweig et al. (1972) placed rats in either impoverished or enriched cages for 30-60 days and conducted post-mortem studies. They found that rats in enriched environments (EC) developed a heavier and thicker brain cortex, with the frontal lobes being heavier and showing more acetylcholine receptors.
This study supports neuroplasticity by demonstrating that the rats’ brains physically changed as a result of a stimulating environment. Although there are concerns about extrapolating results from animal studies to humans, subsequent research on humans has found similar results, indicating that this finding is reliable and applicable across species.
Therefore, this empirical evidence not only increases the validity of the neuroplasticity theory but also enhances our understanding of how the brain can adapt and change in response to our environment.

Question 133

8. Plasticity and functional recovery

limitation

Answer 133

A limitation of the role in the brain’s ability to recover from injury is due to age, with younger individuals generally experiencing better functional recovery outcomes.
Plata et al. (2008) conducted a study investigating the impact of age on recovery from traumatic brain injury (TBI). Their findings indicated that younger patients had a higher likelihood of achieving a better recovery compared to older individuals. The study showed that younger brains exhibit more robust neuroplasticity, allowing for more effective reorganization and compensation for lost functions.
This study highlights the concept of cognitive reserve, which tends to be higher in younger individuals due to greater neuroplasticity. As people age, the brain’s ability to form new neural connections diminishes, making recovery from injuries more challenging.
Therefore, this research underscores the importance of considering age as a crucial factor in functional recovery from brain injuries

Question 134

9. Ways of studying the brain

4 methods of studying the brain

Answer 134

-fMRI (functional magnetic resonance imaging)
-EEG’S
-ERP’S (event related potentials)
-Post mortem examinations

Question 135

9. Ways of studying the brain

Explain the 2 types of resolution that are important for imaging

Answer 135

1) spatial resolution: refers to the smallest feature (or measurement) that a scanner can detect. Greater spatial resolution allows psychologists to discriminate between different brain regions with greater accuracy

2) temporal resolution:
the accuracy of the scanner in relation of time or how quickly the scanner can detect changes in brain activity
How many scans your taking in a period of time

Question 136

9. Ways of studying the brain

How does fMRI work?

Answer 136

Based on neurovascular coupling of neural activity and blood oxygenation
Changes in blood oxygenation and deoxygenation
Deoxygated area = more activate area
Neural vascular coupling between synaptic transmission of the neural response and the BOLD response

Question 137

9. Ways of studying the brain

Strengths of fMRI

Answer 137

High spatial resolution: can distinguish different brain areas and regions well

Non invasive: no use of radioactive tracers unlike PET

Question 138

9. Ways of studying the brain

Limitation of fMRI

Answer 138

• low temporal resolution of approx 0.8 secs
• expensive so potentially decreases sample size so lowers reliability
• indirect measure of neural activity, not causational
• movement artifacts can disrupt image
• accessibility eg: no pacemakers or metal or tattoos or pregnant women due to strong magnetic field

Question 139

9. Ways of studying the brain

What are EEG’s

Answer 139

Measures the electrical activity of scalp electrodes while the subject is at rest

Electrode caps, with different configurations, higher spacial resolution with more number of electrodes on cap

Question 140

9. Ways of studying the brain

What is the basis of the EEG signal
What’s the 4 types of EEG waves and how do they differ

Answer 140

Alpha
Delta
Theta
Beta

Question 141

9. Ways of studying the brain

How are EEG’S used

Question 142

9. Ways of studying the brain

Advantages of EEG’s

Answer 142

• high temporal resolution
• non-invasive
• low cost: can have a higher sample size
• portable: accessibility for more participants for example; can bring to the patient whoch helps patients who are severely ill, old or antisocial p
• Wider range of populations eg: can use anyone as all you need to do is put a cap on the: contributed to sleep studies
• Direct measure As you’re just measuring the neural levels and activity

Question 143

9. Ways of studying the brain

Limitations of EEG

Answer 143

Low spatial resolution
Susceptible to artefacts
Limited to surface activity: can only measure the 3mm cerebral cortex, so you can pick up some activity from other brain regions but don’t know where the activity/signals are coming from, making it difficult to interpret and therefore harder to diagnose or make conclusions
Requires skilled technicians

Question 144

9. Ways of studying the brain

What are ERP’s

Answer 144

event-related potential (ERP’s)
Cognitive or sensory situations
Very similar to EEG but Averaged and time locked
Averaged and time locked response to a stimulus
They isolate specific neural responses associated with sensory, cognitive and motor events
They use a statistical averaging technique
Triggered by a cognitive or sensory stimulus

Question 145

9. Ways of studying the brain

Advantage of ERP’s

Answer 145

gh temporal resolution (same as EEG’S)
Non invasive
Relatively low lost
Sensitive to cognition

Question 146

9. Ways of studying the brain

Limitatioms of ERP’s

Answer 146

Low spatial resolution
Low signal-to-noise ratio and that’s why you need to use averages to cancel out the noise

Question 147

9: Ways of studying the brain

How is post-mortem data used in psychology research?

Question 148

9: Ways of studying the brain

Advantages of post-mortem research

Answer 148

Highly detailed analysis – molecular level, microscopic so can have high spacial resolution
Access to human tissue
Validate imaging data – used to agree with data from imaging studies
Identify disease mechanisms

Question 149

9: Ways of studying the brain

Limitations of post-mortem research

Answer 149

Limited availability – majority comes from accidents and diseases that killed.
This creates a selection bias
Time-dependant changes – can cause artifacts as the brain tissue dies after death
Ethical considerations – always need doner or next of kin consent, should we be taking brains from dead people
No temporal resolution

Question 150

10. Circadian rhythms

What are biological rhythms

Answer 150

Cyclical patterns within biological systems

Question 151

10. Circadian rhythms

What’s the Frequency of:
1) circadian
2) infradian
3) ultradian

Answer 151

1) circa = around dian=day
2) lasts longer than one day
3) more than one per day

Question 152

10. Circadian rhythms

What are endogenous pacemakers?

Answer 152

Internal (endo) mechanisms that govern biological rhythms eg: pineal gland

Internal biological clocks

Question 153

10. Circadian rhythms

What are exogenous zeitgebers?

Answer 153

External (external) mechanisms that govern biological rhythms eg: light/dark
‘Time givers’

External influences

Question 154

10. Circadian rhythms

What is the relationship between endogenous pacemakers and exogenous zeitgebers?

Answer 154

All organisms have biological rhythms which are governed by endogenous pacemakers and entrained by exogenous zeitgebers.

Question 155

10. Circadian rhythms

What is the sleep wake cycle

Answer 155

Sleep wake cycle is a free running cycle by an endogenous pacemaker working as a body clock

Question 156

10. Circadian rhythms

What is the biological basis for the sleep-wake cycle?

Answer 156

Superchiasmatic Nucleus is the endogenous pacemaker that controls our sleep wake cycle.
SCN is in the hypothalamus.
When the optic nerves from the eye cross over, it gets stimulated by light that penetrates our closed eye lids
SCN recieves info about light and dark directly from the eye retina so light is the exogenous zeitgeber in the sleep/wake cycle

Question 157

10. Circadian rhythms

What role does the pineal gland play?
What is the role of melatonin?

Answer 157

The pineal gland increases the production of melatonin which we know induces sleep
Sunlight in the morning stops the production of melatonin. Increasing cortisol which increases wakefulness.

SCN -> sends messages to pineal gland -> dark – night = increases melatonin -> induces sleep

Question 158

10. Circadian rhythms

What is the role of homeostasis

Answer 158

Maintenance of constant internal environment
It controls (along with the circadian rhythm) sleeping and wakefulness

When an individual has been awake for a long time, homeostasis tells the body that there’s a need for sleep increases throughout the day, reaching its maximum in late evening

Question 159

10. Circadian rhythms

How is body temp a circadian rhythm

Answer 159

It’s lowest (36°) at 4:30am and highest (38°) at 6pm
Sleep occurs when core temp begins to drop, it rises during last few hours of sleep promoting a feeling of alertness in the morning

Question 160

10. Circadian rhythms

Micheal Siffres study

Answer 160

Aim: investigate the human body’s natural circadian rhythms in the absense of external cues

Procedure:
-isolated himself Ina cave for 6 months, away from natural light, clocks, sunlight.
Controlled environment including temp and humidity
- he recorded his sleep-wake cycles, body temp and psychological state, while researchers monitored with activities remotely

Findings:
His cycle extended to 25 hours, so each ‘day’ lasted an hour longer than the natural 24 hour cycle so his sleep and waking times drifted later each day

Conclusion:
The circadian rhythm is naturally slightly longer than 24 hours
External cues like natural light rest the internal clock to align with the 24 hour day.

Question 161

10. Circadian rhythms

Other evidence for extended sleep wake cycles in the absence of external light

Answer 161

Aschoff and Wever convinced p’s to spend 4 weeks in WW2 bunker deprived of light
All but 1 ppt displayed a circadian rhythm of 24-25 hours the other extended to 29 hours
Researchers sped up the clocks

Question 162

10. Circadian rhythms

What’s desynchronisation and how does it occur wit sleep

Answer 162

Occurs when individuals internal body clock is out of sync with the external environment
Jet lag:
- Caused by travelling across several time zones within several hours
- Internal clock (SCN) isn’t synchronised with the day time-night time rhythm at the place of arrival
- Social cues are involved, adapting to local times for eating and sleeping, entraining circadian rhythms
- Jet lag causes insomnia, fatigue, irritability, poor concentration

Question 163

10. Circadian rhythms

Describe Ralph’s study on sleep wake cycle in humans

Answer 163

Bred a group of hamsters to follow 20 hour cycle
SCN cells were removed and transplanted into brains of rats
Rats adapted to the 20 hour cycle

• Their Brian’s were transplanted with SCN cells from 24 hour cycle
• Cells from SCN were removed from rats with the 24 hour cycle of neural activity persisted in the isolated cells
• Suggests circadian rhythms were primarily controlled by evolutionary determined biological structures

Question 164

10. Circadian rhythms

What experimental biological evidence is there for sleep-wake cycles existing outside the body?

Answer 164

Yamasaki
Found isolated lungs and livers and other tissues grown in a lab still persist in showing circadian rhythms
Suggests cells are capable of amounting a circadian rhythm even when they’re not under control of any brain structures that most boldly cells are tuned into following a daily circadian rhythm

Question 165

8/16 marker hasn’t come up before:

10. Circadian rhythms

Strength of circadian rhythms

Answer 165

P: evidence supporting the role of the Suprachiasmatic Nucleus (SCN) as a crucial endogenous pacemaker in regulating the sleep-wake cycle is from animal data showing the consequences of SCN ablation
Eg: DeCoursey et al. (2000)
destroyed the SCN connections in the brains of 30 chipmunks and observing them in their natural habitat for 80 days. The researchers found that the chipmunks’ sleep-wake cycles
disappeared, and a significant proportion of them were killed by predators, likely because they were awake and vulnerable when they should have been asleep.
Ex: support for the hypothesis that the SCN is essential in establishing and maintaining the circadian rhythm, particularly the sleep-wake cycle. The study’s ecological validity is enhanced by the fact that the chipmunks were observed in their natural environment, making the findings more applicable to real- world settings.
L: validating the role of the SCN,

Question 166

8/16 marker hasn’t come up before:

10. Circadian rhythms

Limitations of circadian rhythms

Answer 166

P: Siffres cave study into sleep wake cycle has methological issues
Eg: lack of control as he used artificial light when im the cave. Which could’ve confounded the results as other research has shown circadian rhythms can be adjusted as a result of dim lighting
Ex experimenter bias, influencing results of study
L: reduces the interval validity, impact of extraneous variables means it’s hard to isolate the effect of the IV on the DV, through this is somewhat mitigated by replication from other studies

P: limitation of the argument that light is the main exogenous zeitgeber for the sleep wake cycle is that temperature may be more important than light in determining circadian rhythms.
Buhr et al. (2010) found that fluctuations in temperature set the timing of cells in the body and caused tissues and organs to become active or inactive. Buhr claimed that information about light levels is transformed into neural messages that set the body’s temperature.
Ex: Body temperature fluctuates on a 24-hour circadian rhythm and even small changes in it can send a powerful signal to our body clocks. This shows that circadian rhythms are controlled and affected by several different factors, and undermines the validity of the theory that light is the only external zeitgeber for the sleep wake cycle.

Question 167

11. Infradian rhythms

What is an infradian rhythm? Give an example, with details

Answer 167

Biological rhythm a which is governed by a cycle which lasts more than one day

Menstrual cycle and seasonal affective disorder

Question 168

11. Infradian rhythms

Describe the sequence of the menstrual cycle

Answer 168

28 day cycle
2 phases: Luteal phase and Follicular phase

Luteal: progesterone helps the womb lining to grow thicker to prepare for embryo implantation.

Follicular: rising levels of oestrogen causes ovary to develop and ovulate

Question 169

11. Infradian rhythms

Describe McClintock and Stern study

Answer 169

Aim: investigate whether the menstrual cycle is influenced by pheromonal secretions from other women

Procedure:
29 female uni students, not on birth control
Design: quasi

Findings:
They inhaled secretions from women who were about to ovulate, their menstrual cycles became shorter
Their menstrual cycle became longer
68% of women experienced changes to their menstrual cycle

Conclusion:

Question 170

11. Infradian rhythms

What’s seasonal affective disorder

Answer 170

A depressive disorder which has a seasonal pattern of onset, and is described and diagnosed as a mental health disorder by DSM-5
Symptoms: persistent low mood

Question 171

11. Infradian rhythms

What’s a yearly cycle called

Answer 171

Circannual rhythm

Question 172

11. Infradian rhythms

What is a potential mechanism for seasonal affective disorder?

Answer 172

Caused by melatonin
During the night, the pineal gland secretes melatonin until dawn when there’s an increase of light
During winter, the lack of light Im the morning means the secretion process contributes longer
Has a knock on effect on production of serotonin in the brain, melatonin levels increase due to prolonged darkness, leading to lower levels of serotonin

Question 173

11. Infradian rhythms

Treatment for SAD

Answer 173

SSRI’s
Light therapy treatment

Question 174

11. Infradian rhythms

2 strengths of infradian rhythms

Answer 174

P: menstrual cycle is influenced by exogenous zeitgebers is supporting empirical evidence from a case study.
Eg: Reinberg reported a women who spent 3 on this isolated in a cave with minimal light, only a small lap. During her period, her menstrual cycle shorted from 28 days to 25.7 days
Ex: suggests the reduction in light exposure, a key exogenous zeitgeber
, directly influenced the length of her menstrual cycle.
C: methodological Limitatioms of study – reliance on a single ppt and lack of controls during time in cave eg: stress, dietary changes, temperature
L: provides evidence supporting the idea that external environment factors can significantly impact infradian rhythms which increases validity but should be treated with caution as it’s a case study

P: evidence for infradian rhythms, such as the menstrual cycle, is that they play a significant role in regulating human behavior, particularly in relation to sexual preferences.
Eg: Eg: Penton-Volk conducted research showing that omen during their least fertile stage preferred men with more feminine faces, and in their most fertile stage preferred men with more masculine face
Ex: suggests women’s sexual behaviour

Question 175

11. Infradian rhythms

Limitation

Answer 175

A limitation of early research into menstrual cycle synchronization, such as the studies conducted by McClintock, is the lack of rigorous control over potential confounding variables.

While the research attempted to demonstrate exogenous influences on biological rhythms, it failed to account for a variety of factors that could independently affect the timing of a woman’s menstrual cycle, such as stress, dietary changes, physical activity, and even environmental factors like light exposure.
This methodological flaw undermines the internal validity of the findings, as it becomes difficult to ascertain whether observed synchrony is a genuine effect of pheromonal interactions or merely a coincidence arising from these uncontrolled variables. Furthermore, the reliance on self- reported data in these studies could have introduced bias, further questioning the accuracy of the results.
Therefore, the lack of rigorous controls and the potential for these confounding factors mean that these studies might not accurately measure the intended phenomenon, casting doubt on the robustness of their conclusions, and undermining the validity of the theory.

Question 176

12. Ultradian rhythms

How many stages of sleep are there?

Answer 176

5

Question 177

12. Ultradian rhythms

Over what time frequency do they repeat?

Answer 177

5 stages that all together span over 90 mins approx and repeat throughout sleep

Question 178

12. Ultradian rhythms

Describe the features of Stages 1 and 2

Answer 178

Light sleep, when a person can be easily woken
At the beginning of sleep, brain wave patterns start to become slower and more rhythmic (alpha and theta waves)

Question 179

12. Ultradian rhythms

Describe the feature of Stages 3,4 and 5

Answer 179

and 4: Involves delta waves which are slower still and have a greater amplitude than earlier wave patterns
This is deep sleep or slow wave sleep and it’s difficult to wake someone at this point
Stage 5: REM (rapid eye movement) sleep the body is paralysed yet brain activity speeds up significantly in a manner that resembles the awake brain.
Stage assossiated with dreaming

Question 180

12. Ultradian rhythms

What change occurs over the approximately 5 cycles of the sleep stages?

Answer 180

Sleep staircasing describes progression through the different stages of sleep in an strutted pattern throughout the night
Individuals sleep typically moves from lighter stages to deeper stages and back to lighter stages before entering REM sleep
Resembles a staircase, with each step representing a different stage of sleep

Question 181

12. Ultradian rhythms

Describe the study and findings of Dement & Kleitman (1957)

Answer 181

Aim:
Investigate the relationship between eye movements in REM and non-REM sleep

Procedure:
Monitored 9 adults for 6-17 nights. Their brain activity was recorded on an EEG
They all consumed no caffeine or alcohol as a control

IV: whether they woke up from REM/NREM
DV: whether they could recall a dream and if so the details

Findings:
-more dreams were recalled I’m REM (153) than NREM (11)
-ppts could accurately estimate dream duration
-eye movements were strongly related to dream content eg: one said looking up and down at a ladder(vertical)

Conclusion:
REM activity during sleep was highly correlated with the experience of dreaming, brain activity varied according to how vivid dreams were, ps woken during dreaming reported very accurate recall of their dreams

Question 182

12. Ultradian rhythms

How are meal patterns an ultradian rhythm

Answer 182

Follows a 3-5 hour cycles
Influenced by:
-biological basis - tied to body metabolic processes, influencing in blood sugar levels, release of gherlim (stimulates appetite) and insulin (manages blood sugar levels) and laptop (satisfies appetite)
-environmental and social influences - times of meals can be affected by work schedules, social norms and food availability

Question 183

12. Ultradian rhythms

One strength

Answer 183

P: One strength of understanding ultradian rhythms, such as sleep cycles, is that it helps us grasp age-related changes in sleep patterns.
Ex: research shows slow-wave sleep (vital for growth hormone production) decreases with age.
Van Cauter suggests this reduction may contribute to the physical impairments commonly observed in older adults due to decreased release of growth hormones during sleep
Ex: when slow wave naturally declines with age, interventions like relaxation techniques and medications can enhance this stage, potentially mitigating some age-related health issues.
L: this highlights the practical value of understanding ultradian rhythms as it informs clinical treatments aimed at improving life quality of older adults

Question 184

8/16 marker hasn’t come up before:

12. Ultradian rhythms

2 limitations

Answer 184

P: One significant methodological issue in sleep studies is the low ecological validity due to the highly artificial environments in which participants are studied.
Eg: ppts are often required to sleep in labs, wired to EEG machines, restricted from consuming alcohol or caffeine. This is far removed from normal sleeping comdotioms, so low mundane realism and potentially affecting sleep naturalness
Ex: this artificial environment can also introduce demand charectaristics, when ppts alter their behaviour such as providing inaccurate dream recalls due to annoyance, a desire to return to sleep early or embarrassment.
The small sample size often limited to specific demographics raises concerns about generalisability of findings to target population
L: suggests while sleep studies provide valuable insights but findings aren’t fully reflective of real world sleep patterns and may be limited in application to different populations

One limitation of studying the sleep cycle is the significant individual differences that exist between people.
Eg: Tucker found large variations in duration of each sleep stage among ppts, particularly in stages 3 and 4 which are crucial for deep sleep and restorative processes
Ex: these differences are likely influenced by biological factors eg: genetics, age, health. Meaning them challenging to control or predict in research settings
L: this variability complicates the use of a nomothetic approach in sleep research and suggets generalised findings may not apply equally across all individuals, potentially limiting the applicability and generlisability of research outcomes

Question 185

What’s the resting potential

Answer 185

-65mV (also called polarised state)