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Psychology Paper 2 > Biopsychology > Flashcards

Biopsychology Flashcards

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1
Q

The nervous system

A

-Specialised netwrok of cells in the human body and is our primary internal communication system
-Based on electrical and chemical signals
-Average response time is 0.25s but can be as quick as 100milliseconds
Functions: to collect, process and respond to information in the environment
- To coordinte the working of different organs and cells in the body
Divided into 2 subsystems : Central nervous system and Peripheral nervous system

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2
Q

The Central nervous system

A

-Brain and spinal cord
-Brain is the centre of all conscious awareness.
-The brains outer layer, Cerebral cortex only found in mammals
-Brain is highly developed in humans and distinguished our higher mental functions of other animals.
-Brain divided into 2 hemispheres
-Spinal cord is an extension of the brain that passes messages to and form the brain and connects nerves to the PNS. Also responsible for reflex actions

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3
Q

The peripheral nervous system

A

-Transmits messages, via millions of neurons (nerve cells) to and from the CNS
-Afferent (sensory) neurons to CNS
-Efferent (Motor) neurons away from CNS
Divided into:
-Automatic nervous system: Governs vital functions in the body such as breathing,heart rate,digestion,sexual arousal and stress responses , involuntary
-Somactic nervous system: Governs muscle movement and recieves infromation from sensory receptors, voluntary, controls skeletal movement

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4
Q

Automatic nervous system

A

Sympathetic nervous system:Increases bodily activities like Noradrenaline.
-Activates in stress response (gifht or flight) e.g heart rate increase,sweat increase, dilates pupils
Parasympathetic nervous system:Decreases bodily activities . Releases acetylcholine . Activates in rest .e.g heart rate decrease ,sweat decrease

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5
Q

Homeostatis

A

Regulation of internal environment so balanced between parasympethic and sympathetic systems

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6
Q

Nervous system diagram

A
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7
Q

The endocrine system parts

A

Glands and Hormones
Endocrine system and ANS working together: flight or fight

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8
Q

Glands and hormones in the endocrine sytem

A

-Work alongside nervous system to control vital functions in the body
-Acts more slowly than nervous system but has widespread and powerful effects
-Glands produce hormones e.g Thyroid gland
-Hormones are secreted into bloodstream and affect any cell in the body that has a receptor for that particular hormone
-Most hormones affect cells in more than one body organ leading to many diverese and powefful responses
e.g Thyroid gland produces hormone thyroxine
-This affects cells in the heart (increases heart rate)
-Also affects cells throughout body increasing metabolic rates (the chemical procsesses taking place in the cells)
-This affects growth rates
-Key endocrine gland is the pituitary gland, in brain
-Often called master gland as it controls the release of hormones from other endocrine glands in the body

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9
Q

Main endocrine glands in the body

A
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10
Q

Endocrine and ANS working together : Fight or flight

A

Work together during a stressful event
-When a stressor is percieved, the hypothalamus (in brain) activates the pituritary gland and triggers activity in the sympathetic branch of the ANS
-ANS changes from Parasympathetic state (resting) ti the sympathetic state (physiologically aroused)
-Adrenaline is released form the adrenal medulla into the bloodstream
-Adrenaline triggers physiological changes in the body e.g increased heart rate which creates the physiological arousal necessary fr the fight or flight response
-Happens immediately and automatically
-When threat passes, the parasympathetic nervous system returns the body to its resting state.
-PNS works antagonistically to the sympathetic system
-Reduces activities of the body that were increased by actions of the sympathetic branch aka Rest and Digest

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11
Q

Neurons transmit how

A

Electrically and chemically

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12
Q

3 Types of neurons

A

Sensory neurons, relay neurons and motor neurons

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13
Q

Types of neurons diagram

A
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14
Q

The structure of a neuron

A

-From less than a millimetre to a metre long
-Cell body/soma includes a nucleus which contains the genetic material of the cell
-Branchlike structures called Dendrties protude from the cell body that carry nerve impulses from neighbouring neurons towards the cell body
-Axon carries the impulses away from the cell body down the length of a neuron
-Axon is covered in myelin sheath that protects the axon and speeds up electrical transmission of the impulse
-If myelin shath was continious it would reverse effect and slow down the electrical imlse so it is segmented by gaps called Nodes of Ranvier. They speed up the transmission of the impulse by forcing it to jump across the gaps along the acon
-At the end of the axon are terminal buttons that communicate with the next neuron in the chain across a gap called the synapse

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15
Q

Location of neurons

A

-Cell bodies of motor neurons may be in the Central Nervous system but axons form part of the Peripheral nervous ststem
-Sensory neurons locates outside of central nervous system, in the Peripheral nervous system in clusters known as Gangla
-Relay neurons make up 97% of most neurons and are found within the brain and visual system

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16
Q

Electrical transmission of neurons

A

When neuron is in a resting state the inside of the cell is negatively charged compared to the outside
-When a nueron is activated by a stimulus, the inside of the cell becomes positively charged for a split second, causing an action potential to occur
-This creates an electrical impulse that travels own the axon towards the end of a neuron

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17
Q

Neuron

A

Basic building blocks of the nervous system, nerve cells that process and transmit messages through electrical and chemical signals

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18
Q

Sensory neuron

A

Carry messages from the PNS to the CNS. They have long dendrites and short axons

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19
Q

Relay neuron

A

Connect the sensory neuron to the motor or other relay neurons.
Short dendrites and short axons

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20
Q

Motor nueron

A

Connect the CNS to effectors such as muscles and glands. Short dendrites and long axons

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21
Q

Synaptic transmission parts

A

Chemical transmissions
Neurotransmitters
Excitation and inhibtiion
Summation

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22
Q

Synaptic transmission : Chemical transmission

A

Neurons communicate with eachother within groups known as neural networks
-Neurons are sepereated by gaps from the next called synapse
-Signals between neurons are transmitted chemically across the synapse
-When the electrical impulse reaches the endof the neuron (the presynaptic terminal) it triggers the release of neurotransmitter from tiny scas called synaptic vesicles

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23
Q

Chemical transmision diagram

A
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24
Q

Synaptic transmission: Neurotransmitters

A

-Neurotransmiters are chemicals that diffuse across the synapse to the next neuron in the chain
-Once a neurotransmitter crosses the gap, it is taken up by a postsynaptic receptor site on the dendrites of the next neuron
-The chemical message is converted back into an alectrical impulse and the process of transmission begins again in this other neuron
-Direction of travel is one way because the neurotransmitters are released from the presynaptic neuron terminal and recieved by the post synaptic neuron (at the receptor sites)
-Several dozen types of neurotransmitter have been identified in the brain as well as the spinal cord and glands
-Each neurotransmitter has its own specific molecular structure that fits perfectly into a postsynaptic receptor site
-They also have specialist functions e.g Acetylcholine (ACh) is found at each point where a motor neuron meets a muscle and upon its release, it will cause muscles to contract

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25
Q

Synaptic transmisions :Excitation and Inhibiton of neurotransmitters

A

Neurotransmitters either have excitatory or inhibitory effect on the neighbouring neuron
-e.g Serontonin causes inhibition in the recieving neuron, resulting the neuron becoming more negatively charged and less likely to fire
-However adrenaline (both hormone and neurotransmitter) causes excitation of the postynaptic neuron by increasing its positive chage and making it more likely to fire

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26
Q

Synaptic transmissions: summation of postsynaptic neuron

A

Whether a postsynapti neuron fires is deided by summation process
-The excitaroy and inhibitory influences are summed so if the net efffect of the postsynaptic neuro is inhibitory then the postsynaptic neuron is less likely to fire
-If the net effect is excitatory it is more likely to fire i.e the inside of the postynaptic neuron momentarily becomes positively charged
-Once electrical impulse is creeated it travels down the neuron
-Therefore th action potential of the postynaptic neuron is only triggered if the sum of the excitatory and inhibitory signals at any one time reaches the threshold

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27
Q

Synaptic transmission

A

The process of neighbouring neurons communicating with eachother by sending chemical messages across the synapse that seperates them

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28
Q

Neurotransmitter

A

Brain chemicals released from synaptic vesicles that can relay signals across the synapse from one neuron to another
-Neurotransmitters can be broadly divided into those that perfrom an excitatory function and those that perform an inhibitory function

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29
Q

Excitation

A

When a neurotransmitter, such as adrenaline increases the positive charge of the postsynaptic neuron
This increases the likeliihood that the postsynaptic neuron will pass on the electrical impulse

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30
Q

Localisation of function definition

A

Theory that diferent areas of the brain are responsible for specific behaviours, processes or activities

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31
Q

Motor area

A

A reigon of the frontal lobe involved in regulating movement

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32
Q

Somatosensory area

A

Area in the pareital lobe that porcesses sensory infromation such as touch

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33
Q

Visual area

A

A part of the occipital lobe that recievs and processes visual information

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34
Q

Auditory area

A

Located in the temporal lobe and concerned with the analysis of the speech based information

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35
Q

Broca’s area

A

An area of the frontal lobe in the left hemiphere, responsible for speech production

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36
Q

Wernicke’s area

A

An area of the temporal lobe (encircling the auditory cortex) in the left hemisphere, responsible for language comprehension

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37
Q

Localisation of function parts

A

Localisation vs holistic theory
Hemispheres of the brain
The motor, somatosensory, visual and auditory centres
The language centres of the brain

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38
Q

Localisation of function: Localisation vs holisitc theory

A

Broca and Wernicke discovered that specific areas of the brain are associated with particular physical and psychological functions
-Before they supported the holistic theory of the brain, that all parts of the brain were involved in the processing of thought and action
-Broca and Wernicke argued for the localisation of function aka Cortical specialisation, the idea that different parts of the bain perfrom different tasks and are involved with different parts of the body. If a certain area of the brain becomes damaged through illness of injurt, the function associated with that area will also be affected

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39
Q

Localisation of function:Hemispheres of the brin

A

The Cerebum (main part of the brain) is divided into the left and right hemisphere
-Some of our physical and psychological functions are controlled or dominated by a particular hemisphere, called lateralisation
-Activity on the left side of body is controlled by the right hemisphere and the right is controlled by the Left hemisphere
-Language is also linked to the left

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40
Q

Localisation of function: The motor

A

The cerebral cortex, outer layer of brain, is divided into lobes
-Frontal lobe, parietal lobe , occipital lobe and the temporal lobe
-Motor area is at the back of the frontal lobe, both hemispheres, which controls voluntary movement in the opposite side of the body. Damage leads to loss of control over fine movements

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41
Q

Localisation of function:The somatosensory

A

-At the front of the parietal lobes which is seperated by the central sulcus
-Somatosensory is where sensory infromation from the skin is represented
-The amount of somatosensory area devoted to a particular body part denotes its sensitivitye.g receptors in face and hand occupy over half of the somatosensory area

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42
Q

Localisation of function: The Visual area

A

-In the occipital lobe at the back of the brain
-AKA visual cortex
-Each eye sends infromation from the right visual field to the left visual cortex and from the left visual field to the right visual cortex
-Means damage to the left hemisphere can produce blindnesss in the right visual field of both eyes

43
Q

Localisation of function:The Auditory area

A

-In the temporal lobes
-Analyses speech based information
-Damage may cause partial hearing loss
-The more extensive the damage, the more extensive the loss
-Also, damage to a specific area of the temporal lobe - Wernicke’s area may affect the ability to comprehend language

44
Q

The language centres of the brain

A

-Language is restricted to the left side of th brain
-Broca identified a small area in the left frontal lobe responsible for speech production
-Damage to Broca’s area causes Broca’s aphasia which is characterised by speech that is slow and non fluent
-Often have difficulties with prepositions and conjunctions e.g a, the, and
-Wernicke’s area in the left temporal lobe was responsible for language understanding
-This results in Wernicke’s aphasia when damaged
-People who have Wernicke’s aphasia will often produce nonsense words (neoglisms) as part of their speech
-No problem producing language but severe difficulties understanding it- speech they roduced was fluent but meaningless

45
Q

Phineas Gage

A

Gage had a pole go through his left cheek, passing behind his left eye and removing his left frontal lobe
-From calm and reserved to rude and quick tempered
-Suggests frontal lobe is responsible for regulating mood

46
Q

Laterlisation of the brain diagram draw it

A
47
Q

Laterlisation of function in the brain evulation

A

-Evidence from neurosurgery
-Brain scans
-Language localistion questioned
-Gage

48
Q

Hemispheric laterlisation definition

A

Idea that two hemispheres of the brain are functionaly different and that certain mental processes are mainly controlled by one hemisphere rather than the other e.g language which is localised aswell as laterlised

49
Q

Split brain research

A

A series of studies which began in the 1960s and ongoing involving people with epilepsy who ahd experienced a surgical seperation of the hemispheres of their brain to reduce the severity of their epilepsy
-This enabled researchers to test lateral functions of the brain in isolation

50
Q

Hemispheric laterlisation parts

A

Localisation and laterisation
Left and right hemispheres

51
Q

Hemispheric laterlisation: Location and laterlisation

A

For some functions, the localised areas apear in both hemisheres e.g Vision. The visual area is in the left and right occiptal lobe ,lovcated in the left and right hemisphere
-not language

52
Q

Hemispheric laterlisation: Left and right hemispheres

A

-Language’s two main centres are only in the Left hemisphere for most people
-Broca’s area is the elft frontal lobe and Wernicke’s area is the left temporal lobe, thus language is laterlised
-The right hemisphere cano only produce basic words and phrases but contributes to the emotional contect to what is being said
-Led to the suggestion that the LH is the analyser and the RH is the synthesiser
-But the motor area the brain cross wired: contralateral wiring
-The RH controls movement on the left side of the body whilst the LH controls movement of the right
-Vision is both contralateral and ipsilateral (opposite and same sided)
-Each eye receives light from the left visual field and the right visual field
-The LVF of both eyes is connected to the RH and the RVF of both eyes is connected to the LH
-This enables the visual areas to compare the slightly different to compare slightly different perspective from each aye and aids depth perception
-There is a similar arrangement for auditory input to the auditory area and the disparity from the two inputs helps us locate the source of sounds

53
Q

Hemispheric lateralisation evaluation

A

-Validity PET
-Analyser & synthesiser wrong
-Laterlised chickens

54
Q

Split brain research how and why

A

-Split brain operation = devering the connectionsn between the RH and LH, mainly the corpus collosum, a surgery to reduce epilepsy
-During a seizure the brain has excessive elicrtical activity hich travels from one emisphere to the other
-Split brain research studies how the hemisheres function when they cant communcate with eachother

55
Q

Split brain research procedure

A

SPERRY How 2 hemispheres deal with speech and vision
-11 people who had split brain operation had an image projected to the LVF (processed by the RH). In the normal brain, the corpus callosum would immediately share the infromation between both hemispheers giving a complet epicture of the visual world. However presenting the image to one hemisphere of a split brain persoon meant this couldnt happen

56
Q

Split brain findings

A

-Covered 1 eye
When a picture of an object was shown to a particiants RVF (LH), the participant could descibe wat was seen due to langage being on the LH
-Bu said there was ‘nothing there’ with objects shown to the LVF (RH)
-Because in the connected brain, messages from the RH are relayed to the language, but not possibe in a split brain
-Though participants couldnt give verbal labels to objects projected to the LVF, they could select a match object out of sight using their left hand (linked to RH).
-The left hand was also able to select an object most associated to the object presesnted to the LVF (e.g ashtray from cigarrete picture)
-If a pinup picture was shown to the LVF there was just an emotional reaction e.g giggle but the participants reported seei nothing or just a flash of light

57
Q

Split brain conclusions

A

-Certain functions are lateralised in the brain and suppor that the LH is verbal and the RH is silent but emotional

58
Q

Split brain evaluation

A

-Research suport Gazzaniga
-Generlisation issues
-Ethics

59
Q

Brain plasticity

A

-Brain can chnage throughout life
-During infancy, the brain rapidly grows the number of synaptic connections it has up to15,000 per neuron at 2-3
-Twice as many as an adult
-With age, rarely used connections are deleted and frequents are stengthened by processo f synaptic pruning
-Synaptic pruning enables life long plasticity where new neural connections are formed in response to new demands on the brain

60
Q

Research into plasticity

A

-Maguire studied brains of London taxi drivers and found significant more grey matter in the posterior hippocampus than a matched control group
-This is associated with the development of spatial and navigational skills in humans and animals
-London cabbies must take ‘The Knowledge’ asessing recall of streets and routes
-Maguire foudn this learning experience alters the structure of the taxi dirvers’ brains
-Longer taxi men have been in the job, the more pornounced was the structural diference (postiive correlation )
-Draganski imaged the brains of 3 medical students 3 months before and after their final exams
-Learning induced changed pccurred in the posterior hippocampus an the parietal cortex as a result of learning

61
Q

Plasticity evaluation

A

-Negative plasticity drug and limb
-Age and plasticity
-Seasonal brain changes

62
Q

Functoinal recovery definition

A

A form of plasticity . Folowing damage through trauma, the brains ability to redistribute or transfer functions usually performed by a damaged area to another undamaged area

63
Q

Functional recovery after brain trauma

A

Follwing injury or trauma such as a stroke, unaffected areas of the brain can adapt and compensate for those area that are damaged, destroyed or even missing
-Neuroscientist suggests this process can occur quickly, spontaneous recover, nd hen slow down after several weeks or months
-They may then need rehabilative therapy to further their recovery

64
Q

Functional recovery process

A

-Brain can rewire and reorganise itself by forming new synaptc connections close to area of damage
-Secondary neaural pathways that would not tpyically be used to carry out functions are activated to enable functioning
-This is supported by a number of structural changes as:
Axonal sproutin - the growth of new nerve endings which connect with other undamaged nerve cells to form new neuronal pathways
-Denervation supersensitivy - When axons that do a similar job become aroused to a higher level to compensate for the ones that are lost. However it can have a negative consequence of oversinsitivity to messages such as pain
-Recruitment of homologus areas on the opposite side of the brain - Specific tasks can stil be erfromed e.g Broca’s area damaed on the left side of the brain, the rigt sided equivalent can still carry out its functions. After a period of time, functionality may shift back to the left side

65
Q

Functional recovery evautation

A

-Real world application , neurohabilitation
-Cognitive reserve

66
Q

Ways of studying the brain and purpose

A

FMRI
EEG
ERP
Post morten examinations
Investing localisation

67
Q

FMRI

A

Functional Magnetic Resonance Imaging
-Measured brain activity while a person is perfoming a task.
-Detects radio waves from changing magnetic fields
-Can see what reigons of brain are rich in oxygen and thus active
-Detecing changes in blood ocygenation and flow that occur as a result of neural activity in specific parts of the brain
-When a brain area is more active it consumes more oxygen and to meet this increased demand, blood flow is directed to the active area caled haemodyamic response
-Produces 3D images known as activation maps showing which parts of the brain are inolved in a particular mental process and this has important impilcations for understanding localisation of function

68
Q

EEG

A

Electroenecphalogram
-Measures electrical activity in the brain via electrodes fixed to an indiciduals scalp using a skull cap
-Scan recording represents the brain patterns that are generated form the action of thousand of neurons, providing an overall account of brain activity
-By measuring characteristic wave patterns
-Often used by clinicians as a diagnostic tool as unusual arrhythmic patterns of activity mad inidicate abnormalities such as epilepsy, tumours or some sleep disorders

69
Q

ERP

A

Event related potentials
-EEG s too general but cntains all neural responsees for specific sensory, cognitive and mottor events
-Using statistical avreraging tehcnique, all extraneous brain activity from oringal EEG recording is filtered out leaving only those responses that relate to e.g the presentation of a specific or perfromance of a specific task
-Whats remains are ERPS - types of brain waves that are triggred by particular events
-Many dfferent forms of ERP e.g how these are linked to cognitive processes like attaention and perception
-The electrophysiological rsponse of the brain to a specific sensory,congnitive or motor event that can be isolated through statistical analysis of EEG data

70
Q

Post moretn examinations

A

-Anaysis of a brain following their death
-Those subject to post morten examination are likely to be those who have a rare disorder and have experienced unusual deficits in cognitive processes of behaviour during their life
-Areas of damage wihin the brain are examined after death, establishing the likely cause of the affliction the person experienced
-May involve comparison with a neurotypical brain in ordr to ascertain the extent of difference

71
Q

fMRI evaluation

A

Strengths: Safe & Clear
Limit: Expensive & poor temporal resolution

72
Q

EEG evaluation

A

Strengths: Diagnoses and high temporal resolution
Limit: Too generalised

73
Q

ERP evlauation

A

Strengths: Specific & temporal resolution
Limits: Lack of standardisation r.g background noise

74
Q

Post Mortem examinations evaluations

A

Strengths: Useful
Limits: Causation & ethical issues

75
Q

Circadian rhythms

A

Biological rhythms , subject to a 24 hour cycle, which regulate a number of body processes such as the sleep/wake cycle and changes in core body teperature

76
Q

Biological rythms definition

A

Distinct patterns of changes in body activity that confrom to cyclical time periods. Influecnd by internal body clocks (endogenous pacemakers) as well as external changes to the environment (exogenous zeitgebers)
-An example of a circadian rhythms

77
Q

Circadian rythms parts

A

Biological rthms
The sleep wake cycle
Siffre’s svae study
Other research

78
Q

Biological rhythms

A

All organisms are subject to biological rhythms and are important for how body systems behave
-Biological rhythms are goverened by Endogenous pracemakers (internal biological clocks) and exogenous zeitgebers (external changes in the environement)
-Ultradian rhythms occur many times during the day
-Infradian rhythms take longer than a day to complete
-Circannual rhythms take much logner
-Circadian rhythms last around 24 hours e.g sleep wake ycle an core body temperature

79
Q

The sleep wake cycle

A

-Drowsy at nightime is due to effects of day light, an important exogenous zeitgeber on our sleeep wake cycle
-Cycle is also governed by endougenous pacemaker, a biological clock called the suprachismatic nucleus (SCN)
SCN is above the optic chiasm which provided information from the eye about light
-Exogenous zietgebers (light) can reset the SCN

80
Q

Siffre’s cave study

A

-Spent several extended period underground to study the effects of his own biological rhythms
-Deprivedof natural light and sound but access to food and drink
-Spent 2 months until September but believed it was mid August
-Then spent 6 months in a different cave
-In each case his free running biological rhythm settled to around 25 hours though he did continue to fall alseep and wake up on a regular schedule

81
Q

Other research on the sleep wake cycle

A

Wever covinced group of participants to speng 4 weeks in a WW2 bunker deprived of natural light
-All had a circadian rhythm of 24-25 hours except one who had 29
-Both Siffre and bunker study suggest that the natural sleep wke cycle is slightly longer than 24 hours but it is entrained by exogenous zeitgebers associated with the 24 hour day e.g number of daylight hours, typical meal times
-We should not underestimate the influence of exogenous xeitgebers on out internal biological clock
-Folkard stued 12 people who agreed to live in a adark cave for 3 weeks, going to bed at 11.45 pm and waking at 7.45pm
-Researchers gradually sped up the clock so 24 hours only lasted 22 hours
-Only 1 of the participants could adjust t the new regime
-Suggests the existence of a strong free running circadian rhythm cannot be easily over ridden by exogenous zeitgebers

82
Q

Circadian rhythm evaluation

A

-Shift workers
CP: Divorce
-Medical treatment
-Individual differences
-School

83
Q

Infradian rhythm definition

A

A type of biological rythm with a frequency of less than one cycle in 24 hours, such as menstruation and seasonal affective disorder

84
Q

Ultradian rhythm definiton

A

A type of biological rhythm with a frquency of more than one cylce in 24 hours, such as stages of sleep, the sleep cycle

85
Q

Waves during sleep

A
86
Q

Types of infradian rythms

A

The mestrual cycle & Seasonal Affective disorder

87
Q

The mestrual Cycle

A

-An infradian rhythm, governed by monhtly changes in hormon levels which regulate ovulation
-Cycle is the time between the first day of the period, when the womb lining is shed to the day before next period
-Approx 28 days
-During cycle hormone oestrogen causes ovary to devleop egg and release it (ovulation)
-After ovulation, the hormone porgesterone helps the womb lining grow thicker, readying womb for pregnancy.
-If pregancy doesnt occur, the egg absorbs into the body and th womb lining leaves the body (mestrual flow)

88
Q

Synchronising the mestrual flow study

A

-Though it is an endogenous system, evidence suggests it may be influenced by exogenous factors such as cycle of other women
-McClintock studied 29 women wih a history of iregular periods
-Samples of pheromones gathered from 9 women at different stages of their mestural cycles via cotton pad places in arpit
-Pads worn for 8 hours to ensure peromones were picked up
-Pads treted with alchohol and frozen to be rubbed on the upper lip of other participants
-On day one, pads from the start of the mestrual cycle were applied to all 20 women and on day 2, the were give a pad from the second day and so on
-Found 68% of women experienced changes to their cycle which brought them closer to the cycle of their odur donor

89
Q

Seasonal affective disorder

A

-Depressive disorder which has a seasonal patter of onset and is desrcibed as a mental disorder in DSM -5
-Low mood and lack of activity nd interest in life
-AKA winter blues as symptoms are triggered during winter months when number of daylight hours become shorter
-Particular type of infradian rhythm called circannual rhythm as it is subject to a yearly cycle
-Also clased as circadian rhythm as experience of SAD may be due to disruptin of the slep/wake cycle and this can be attributed to polonged periods of daily darkness during winter
-The hormone melantonin is involved
-During night, the pieal gland secretes melantonin until dawn when there is an increase in light
-During winter, lack of light means secretion process continues for longer
-This has a knock on effect of production of serontonin in the brain, chemcical linked to depressive symtoms

90
Q

Ultradian rhythms in sleep stages

A

Stages 1&2: Light sleep and can easil be woken. Stage 1 brain waves are high frquency and have a short amplitude: Alpha waves
Stage 2- alpha waves continue but there are occasional random changes in pattern called sleep spindles
Stages 3&4 : Known as deep sleep of Slow Wave Sleep. The brain waves are delta waves with lower frequency and higher amplitutde. Difficult to wake some one up
Stage 5: REM SLEEP. The body is paralysed yet brain activity resembles the wake brain. Theta waves and the eyes occasionally move around thus rapid eye movement . Dreams experienced but may also occur in deep sleep

91
Q

Infradian rhythms :Menstural cycle research & SAD evaluation

A

-Evolutionary basis
-Methodological limitations
-Real world application Light

92
Q

Ultrdian rhythms sleep Evlauation

A

-Improved understanding
-Individual differences
-Controlled settings

93
Q

Endogenous pacemakers defintions

A

Internal body clocks that regulate many of our biological rhythms such as the influence of the suprachiasmatic nucleus on the sleep wake cycle

94
Q

Exogenouz zeitgebers defitinitons

A

External factors that affect of entrain our biological rhytms such as the influence of light on the sleep wake cycle

95
Q

Sleep wake cycle defintion

A

A daily cycle of our biological activity based on a 24 hour period (circadian rhythm) that is influenced by regular variations in the environment, such as the alternation of night and day

96
Q

Endogenous pacemakers and sleep/wake cycle parts

A

The suprachiasmatic nucleus
Animal studies and the SCN
The pieneal gland and melantonin

97
Q

The suprachiasmatic nucelus

A

-Tiny bundles of nerve cells located in the hypthalamus in each hemisphere of the brain
-One of the primary endogenous pacemakers and maintains carcadian rhythms such as the sleep wake cycle
-Nerve fibres connected to the eye cross an area called the optic chiasm on their way to the let and right visual area of the cerebral cortex
-The SCN lies just aboce the optic chiasm
-It reiceneves infromation about light directly from this sturcture
-This continues with eyes closed, enabling the biological clock to adjust to changing patterns of daylight while we sleep

98
Q

Animal studies and the SCN

A

-DeCoursey destroyed the SCN connections in the brains of 30 chipmunks who were then returned to their natural habitat and obsereved for 80 days
-The sleep wake cycle of the chipmunks disapeareed and by the end of the study a significant proportion of them were killed by predator, because they awak and vulnerable to attack when they shoudlve been asleep
-Ralph bred mutant hamsters with a 20 hour sleep wake cycle
-When the SCN cells fro mthe foetal tissue of mutant hamsters were transplanted into the brains of normal hamsters, thhe cycles of the second group defaulted to 20 hours

99
Q

The pinieal gland and melantonin

A

The SCN passes infromtion on day length and light that it recieves to the pineal gland
-This is another endogenous mechanism guiding the sleep wake cycle
-During night, the pineal gland increases production of melantonin - a chemical that induces sleep and is inhibited during perios of wakefulness
-Melantonin suggested as a casual factor in SAD

100
Q

Exogenous zeitgebers and the sleep wake cycle parts

A

Light
Social cues

101
Q

Light exogenous zeitgeber in the sleepwake cycle

A

-Can reset the body’s main endogenous pacemaker ,the SCN and plays the role in the maintainence of the sleepwake/cycle
-Also indriect influence on key processes such as hormone secretion and blood circulation
-Murphy deonstrated that light may be deteceted by skin receptor sited on the body even when the same information is not recieved my the eyes
15 ppts were woken at various ties and a light pad was shone on the back of their knees
-The researchers managed to produce a deviation in participants usual sleep wake cycle of up to 3 hours
-Suggests light is a powerful exogenous zeitgeber that does need the eyes to exert its influence on the brain

102
Q

Social cues in the sleewake cycle

A

Babies sleep wake cycle is random
-At 6 weeks the circadian rhythm begins and by 16 weeks babies have been entrained by the schedules imposed by parents, including adult determined mealtimes and bed tiems
-Research on jet lag suggets that adpating to local times for eating and sleeping rather than own hunger and fatugue is an effective way of entraining circadian rhythms and beating jet lag when travelling long distances

103
Q

Endogenous pacemakers on sleep evaluation

A

-SCN
-Interactionist
-Ethics of animals

104
Q

Exogenous pacemakers evaluation

A

-environmental observations
-Case study evidence Miles
-Age related
CP: Lights

Psychology Paper 2 (3 decks)

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