Biopsychology

The nervous system

Central nervous system, peripheral nervous system

Central nervous system

Integration and processing of sensory information to create an appropriate motor response of output.
Spinal cord, Brain, brain stem

Spinal cord

transfers messages to and from the brain, responsible for simple reflex actions that don't involve the brain

Brain

Conscious awareness
- frontal lobe
- parietal lobe
- temporal lobe
- occipital lobe

Brian stem

connects the brain and spinal cord, controls involuntary processes

Peripheral nervous system

relay messages from the CNS to the rest of the body.
- somatic nervous system
- autonomic nervous system

Somatic nervous system

facilitates communication between CNS and rest of the world, made up of sensory receptors and motor pathways. Provide muscle response

Autonomic nervous system

controls homeostasis, fight or flight, only consists of motor pathways,
- sympathetic nervous system
- parasympathetic nervous system

sympathetic nervous system

prepare the body for fight or flight

parasympathetic nervous system

relax the body for fight or flight (rest + digest)

The endocrine system

network of glands that secrete chemical messengers (hormones), uses blood vessels:
- hypothalamus, connected to pituitary gland
- pituitary gland, master gland, stimulates other glands
- pineal gland, melatonin - sleep wake cycle
- thyroid gland, thyroxine, metabolism
- adrenal gland, adrenal medulla, adrenal cortex
- testes, testosterone
- ovaries, oestrogen - menstrual cycle

components involved fight or flight

-amygdala - neurones located deep in brain's medial temporal lobe
- limbic system - set of structures that lie on both sides of the thalamus under the cerebrum --\> the hypothalamus, hippocampus, amygdala, several others
- noradrenaline - works on alpha receptors to increase and maintain blood pressure
-norepinephrine - continuously released into circulation
- epinephrine - released during times of stress

flight or flight process

1. a person enters a stressful situation
2. the amygdala is activated which sends a distress signal to the hypothalamus
3. hypothalamus activated the Sympathomedually Pathway - runs through adrenal medulla and sympathetic nervous system (SNS)
4. the SNS stimulates the Adrenal medulla
5. Adrenal medulla secretes adrenaline and noradrenaline
6. adrenaline causes psychological changes to prepare for fight or flight

physiological changes of fight or flight

Increased heart rate
Pupil dilation
Increased breathing rate
Stopping of unimportant functions

fight or flight AO3

Fight or flight or freeze - not limited to 2 responses, Gray 1988
Females tend to befriend - Taylor et al 2002, females more likely to protect their offspring
Modern society - negative effect on health so could lead to heart disease

types of neurones

sensory, relay, motor

sensory neurone

found in receptor cells, carry nerve impulses to spinal cord and brain. Translate nerve impulses into sensations

relay neurone

between sensory input and motor output. Found in brain and spinal cord and allow them to communicate

motor neurone

control muscle movement, release neurotransmitters that trigger a response

parts of a neurone

Dendrite - receives signals from other neurons or from sensory receptor, connected to cell body
Axon - long slender fibre that carries nerve impulses as action potential
Myelin sheath - insulates the axon so that electrical impulses travel faster along the axon
Axon terminal - connects neuron to other neuron using synaptic transmission.

transmission process

stimulus --\> receptor --\> CNS (sensory, relay, motor) --\> effector

synaptic transmission process

1. information passed down the axon of the neurone as action potential (ap)
2. once the ap reaches the axon it transfers across the synaptic vesicles
3. neurotransmitters pass the synaptic gap and bind to receptors on the post synaptic cell
the post-synaptic neurone will then be activated producing either excitatory/ inhibitory effects
a. excitatory neurotransmitters make the postsynaptic cell more likely to fire (i.e noradrenaline)
b. inhibitory makes then less likely to fire (GABA)

localisation of function in the brain meaning

certain functions have certain locations within the brain

brain

provides conscious awareness involved in psychological processes

lobes + areas in the brain

occipital lobe
temporal lobe
parietal lobe
frontal lobe
brocas area
wernickes area

occipital lobe

visual lobe

temporal lobe

auditory information

parietal lobe

integrates information from senses + spatial navigation

frontal lobe

higher order functions: planning, abstract reasoning, and logic

Broca's area

Paul broca
Responsible for speech production
Patient Tan - Aphasia led to damage in this area

Wernicke's area

Carl Wernicke - Language comprehension - damage meant could talk but not understand language

Localisation of function AO3

Fails to account individual differences - Herasty 1997 women have a larger Broca and Wernicke area than men leading to greater ease of language
Equipotentiality theory - basic motor and sensory functions are localised but not higher mental functions
Biological reductionism
Case studies demonstrate the functions - Patient Tan

plasticity meaning

the brain's ability to change and adapt because of experiences --\> research suggested that the brain continues to create new neural pathways and alter existing ones in response to changing experiences

functional recovery meaning

the transfer of functions from a damaged area of the brain after trauma to other undamaged areas
- neuronal unmasking
- axonal sprouting
- stem cells

neuronal unmasking

where dormant synapses open connections to compensate for a nearby damaged area of the brain

axonal sprouting

undamaged axons grow new nerve endings to reconnect neurons whose links were injured or severed

stem cells

can be used through differentiation

Maguire et al (2000) aim

To research whether the role of the hippocampus is to facilitate spatial memory in the form of navigation
Examine whether structural changes can be detected in the brains of people with experience of spatial navigation

Maguire et al method

MRI scans of 16 right handed male London taxi drivers (other 1.5 years) and 50 healthy right handed male non-taxi drivers

Maguire et al results

increased grey matter found in the brains of taxi drivers in the posterior hippocampus. Also correlation found between amount of time spent as a taxi driver and volume in the right posterior hippocampus

Maguire et al conclusion

provides support of brain plasticity and suggests experience can change the structure of the brain

further research of brain plasticity

Draganski et al 2006, Mechelli et al 2004

Grey matter definition

part of the brain that processes information and contains all neuronal cells in your brain

Brain plasticity

Research support - Draganski et al 2006, Mechelli et al 2004, Maguire et al
Applicaiton to neurorehabilitation - motor therapy, electrical stimulation, improved cognitive functions
Biological reductionism

Hemispheric Lateralisation definition

The idea that the 2 halves are functionally different and each hemisphere has a function

hemispheric lateralisation key study

Sperry and Gazzaniga 1967 - used split brain patients who had their corpus callosum using commissurotomy

Sperry and Gazzaniga task

describe what you see, tactile test, drawing faces

Sperry and Gazzaniga results

Right hemisphere - could not describe what was shown/ felt but could identify similar objects and draw clearer pictures

Right hemisphere/ left visual field

Visual task, creativity

Left hemisphere/ right visual field

language, logic, number skills

hemispheric lateralisation AO3

Research evidence - multitasking, Rogers et al (2004) chickens can still find food whilst checking for predators
Language in right hemisphere - Turk et al 2002
Idiographic approach
Methodological - only examined 11 patients

Ways of studying the brain

fMRI, EEG, ERP, Post-mortem

fMRI (functional magnetic resonance imaging)

Measures blood flow in the brain when a person performs a task.
- neurons require energy
-energy comes from glucose and oxygen
- oxygen is released for use by the neurones so the haemoglobin becomes deoxygenated.
-deoxygenated and oxygenated haemoglobin have different magnetic qualities which can be detected to create a dynamic 3D map of the brain

temporal/spatial resolution fMRI

temporal \= 1-4s after
spatial \= accurate within 1-2mm

EEG (electroencephalogram)

Measure electrical activity through electrodes on the scalp.
Information is processed in the brain as electrical activity in the form of action potential.
4 type of EEG patterns: alpha, beta, theta, delta

amplitude definition

the intensity or size of the activity

frequency definition

the speed or quantity of activity

synchronised EEG patterns

recognisable wave form (alpha, beta, delta, theta)
Usually detected during sleep

desynchronised EEG patterns

no pattern. Usually a mixture of all 4 waves, often detected when someone is awake

ERP (event related potentials)

Use electrodes attached to the scalp.
A stimulus is presented to a participant and the researcher looks for activity related to that stimulus.
An average response will be graphed.

Latency definition

The time or interval between the presentation of the stimulus and the response

EEG & ERP temporal/spatial resolution

temporal \= show activity every millisecond
spatial \= only superficial activity, general areas

Post Mortem examination

The study of the physical brain of a person who displayed a particular behaviour before they died
- Iverson \= schizophrenic patients \= higher dopamine concentrations

fMRI use

To understand structure and function - left/right handed tasks
Medical diagnosis
Abnormal activity

EEG use

Sleep studies
Depression, Schizophrenia
Epilepsy
Eating Disorders
Abnormal wave pattern
Diagnostic tool

ERP use

memory research
Information processing
Phobias
Psychiatric disorders

Post Mortem uses

Medical condition alive \= structural abnormalities when dead
Schizophrenia \= enlarged ventricles in the brain
Evidence of localisation of function as a result of trauma or damage

fMRI AO3

+ non invasive
-1-4s temporal resolution
+1-2mm spatial resolution
-Does not provide a direct measure of neural activity

EEG Ao3

+ non invasive
+ 1-10 ms temporal resolution
- superficial general regions only
- electrical activity is detected in several regions it can be difficult to pinpoint exact region

ERP AO3

+non invasive
+ 1-10 ms temporal resolution
- superficial general regions only
+ enable the determination of how processing is affected by experimental manipulation

Post Mortem examination AO3

- deficits a patient displays during lifetime may not be linked to deficits found in the brain

circadian rhythms definition

a pattern of behaviour that occurs and reoccurs every 24 hours being re set by environmental light levels

circadian rhythms examples

Sleep wake cycle - light detected in the eye sends a message to the suprachiasmatic nuclei which coordinates the activity of the circadian system
Body temperature - lowest \= 36 \=4:30 highest \= 38 \= 6
Hormone production

Michael Siffre

spent 61 days in the Southern Alps.
He resurfaced on 17th September but though it was the 20th August

Circadian rhythm AO3

Research support - Michael Siffre
Shift work
Real life application

Infradian rhythm

less than 24 hours

infradian rhythm example

menstrual cycle, hibernation

Stern McClintock (1998)

29 women with irregular periods. 68% of women experienced changes in their cycle to match their odour donor

Infradian rhythm AO3

real life application

Ultradian rhythm

Less than 24 hours

ultradian rhythm example

human sleep patterns, meal patterns

REM

rapid eye movement

NREM

non rapid eye movement

sleep wake cycle

Consists of 5 stages which repeat over 90 mins, on average 5 cycles a night
1 + 2 light sleep \= theta waves
3+4 deep sleep \= greater amplitude
5 \= REM, body paralysed, desynchronised brain waves

Ultradian rhythms AO3

Randy Gardener - awake for 264 hours
Individual differences - Turker et al
Highly controlled research in a lab
Lack of ecological validity

Endogenous pacemakers

the body's internal biological clock (Suprachiasmatic nuclei)

exogenous zeitgebers

external cues - social cues/light etc

endogenous pacemakers/exogenous zeitgebers AO3

Research support of endogenous pacemakers - Morgan bred hamsters with a rhythm of 20 hours - not generalisable to humans
Research support of exogenous zeitgebers - Michael Siffre - importance of light on the sleep wake cycle - but researcher bias and no generalisabilty
Reductionist - over simplified
Influenced by other people and social norms