Biopsychology

What is a neuron?

What is a neuron?

A nerve cell that transmits messages as an electrical signal

What are the branch like structures that stick out from the cell body and carry impulses from neighbouring neurons towards the cell body?

Dendrites

What is the function of the cell body in a neuron

Where the nucleus is located (storing all genetic material). Also where summation happens - signals from different dendrites are summed, determining whether an action potential travels down the axon or not

What is the axon? What does it do?

The branch extending from the cell body that carries impulses away from it towards the terminal buttons.

What is the name of the fatty layer around the axon of some neurons? What does it do?

Myelin sheath. Speeds up the electrical transmission/signal

What are the three types of neuron?

Sensory, Relay, Motor

What is the role of the sensory neuron?

Carries messages from the peripheral nervous system (receptors) to the central nervous system

Which kind of neuron will have long dendrites which are connected to receptors (which detect signals from the environment)?

Sensory neurons

What is the role of a relay neuron?

Transfers messages from sensory neurons to other relay or motor neurons

Where are relay neurons located?

CNS (brain or spinal cord)

What is the role of a motor neuron?

Carries messages from the central nervous system to effectors (muscles and glands)

Which type of neuron will synapse with an effector (such as a muscle or gland), rather than another neuron?

Motor neuron

What are the stages of the reflex arc? Use as many specialist terms as possible.

Stimulus detected by sense organs (receptors) in peripheral nervous system, Sense organs cause signal to be sent along sensory neuron and into the central nervous system, Sensory neuron synapses (connects) with a relay neuron, Relay neuron synapses with a motor neuron, Motor neuron carries signal to an effector, Effector carries out reflex response

How are signals within neurons transmitted?

Electrically

How are signals between neurons transmitted?

Chemically

What is a synapse?

The tiny gap between neurons, across which neurotransmitters diffuse so that information can be passed from one neuron to the next

The name for the process by which nerve impulses are converted from an electrical signal into a chemical one through the release of neurotransmitters into the small gap between one neuron and another.

Synaptic transmission

Describe the process of synaptic transmission. Use as many specialist terms as possible.

Electrical impulse -> the terminal button of the axon of the presynaptic neuron. Release of neurotransmitters (NTs) from synaptic vesicles. NTs diffuse across the synaptic cleft (from high to low concentration). NTs bind with receptors on the dendrite of the post synaptic neuron. Summation of excitatory and inhibitory NTs determines if action potential occurs in the post synaptic neuron. NTs are released from the receptor sites and are broken down or reabsorbed by the presynaptic neuron.

What are neurotransmitters?

Chemical messengers that diffuse across synapses, can be excitatory or inhibitory.

What effect does an excitatory neurotransmitter have?

It makes the postsynaptic neuron more likely to fire (by increasing the positive charge in the neuron)

What effect does an inhibitory neurotransmitter have?

It makes the postsynaptic neuron less likely to fire (by increasing the negative charge in the neuron)

What are the two sides of the brain called?

Hemispheres

What are the four lobes of the brain?

Frontal, parietal, occipital and temporal

What structures make up the CNS?

Brain and spinal cord

What is the function of the CNS?

Origin of all complex commands and decisions - connects the nerves of the peripheral nervous system to the brain and spinal cord.

What type of action is controlled from the spinal cord?

Reflex actions

What is the function of the peripheral nervous system?

Sends information from receptors (outside info) to the CNS, and transmits information from the CNS to the effectors (muscles or glands)

What are the two subsections of the peripheral nervous system?

Autonomic Nervous System and Somatic Nervous System

Which part of the nervous system is the autonomic nervous system part of?

Peripheral nervous system

Which part of the nervous system is the somatic nervous system part of?

Peripheral nervous system

What is the function of the somatic nervous system?

Carries sensory and motor information to and from the spinal cord, controls voluntary muscle movement

What is the function of the autonomic nervous system?

Transmits information to and from internal bodily organs, controls automatic involuntary processes like breathing/heart rate etc. Homeostasis (keeping the body in a stable state)

What are the two branches of the autonomic nervous system? What do they do?

Sympathetic and Parasympathetic

What is the role of the sympathetic nervous system?

Prepares the body to expend energy e.g. for fight or flight. Increase in blood pressure and heart rate, Decrease in digestive activity, Increase in muscle tension, Increase in perspiration, Breathing rate increases, Pupil size increases, Decrease in salivation

What is the role of the parasymptathetic nervous system?

State in which the body maintains body functions and conserves energy as much as possible. E.g. 'rest and digest'. Reduces heart rate. Increased blood flow to digestive areas and reduced flow to skin and muscles.

Give one evaluation of theories of the role of the sympathetic nervous systems

E.g. gender (beta) bias. Women may 'tend and befriend'. Oversimplisitc - Von Dawans (2012) found that that stress can lead to friendly and cooperative behaviour e.g. during 9/11

What is the endocrine system?

Collection of gland and hormones that regulate metabolism, growth and development, sexual function, sleep, mood etc.

What is the main difference between the endocrine system and the nervous system?

Endocrine system controls slow processes, nervous system controls much faster processes.

What is a gland?

An organ in the body that creates a substance such as hormones

What is the hypothalamus?

The structure in the brain that links the nervous system and endocrine system through control of the pituitary gland.

Give an example of a gland and its function

Any from; Thyroid gland - produces thyroxine that increases metabolism. Testes - produce testosterone that controls secondary sexual characterstics in males, and sperm production. Ovaries - produce oestrogen and progesterone that controls the menstrual cycle in females. Pancreas - produces insulin that controls blood sugar levels. Pituitary gland - master gland that controls all other glands, produces hormones like follicle stimulating hormone involved in the control of the menstrual cycle. Adrenal glands - adrenaline and cortisol control the fight or flight and stress responses.

What is a hormone?

Chemical substance secreted into the bloodstream that affects target organs (have cells with the correct receptors)

What is the role of the adrenal glands?

Release adrenaline to prepare the body for the fight or flight response, causes constriction of blood vessels in digestive system to divert blood supply to the heart and lungs.

What are the stages of the fight or flight response?

Stressor identified. Hypothalamus triggers autonomic nervous system to change from parasympathetic to sympathetic state. Hypothalamus also activates the pituitary gland, which signals to adrenal glands to release adrenaline from the adrenal medulla into the bloodstream. Adrenaline triggers physiological changes in target organs. Once threat has passed the parasympathetic nervous system returns the body to resting state.

The endocrine fight or flight response is sometimes said to involve the 'HPA axis'. What does this refer to?

The hypothalamus-pituitary-adrenal gland pathway, which leads to the release of adrenaline from the adrenal medulla

Define localisation of function

The theory that different parts of the brain are responsible for different behaviours, processes or activities.

What is the outer layer of the brain called?

Cortex

What is the somatosensory area of the brain and where is it?

Front of the parietal lobe, processes sensory information such as touch

What is the visual area of the brain and where is it?

In the occipital lobe, receives and processes visual information

What is the auditory area of the brain and where is it?

Temporal lobe, concerned with initial analysis of sound based information.

Where is Wernicke's area and what would happen if it was damaged?

Temporal lobe of left hemisphere. Damage would lead to impairments with the understanding of language

Where is Broca's area and what would happen if it was damaged?

Frontal lobe of left hemisphere (right at the bottom of the motor cortex). Damage would lead to impairments with speech production

Damage to Wernicke's area leads to which type of aphasia? Damage to Broca's area leads to which type of aphasia?

Receptive (Wernicke's). Expressive (Broca's)

Which lobe of the brain is the motor cortex located in? Which side of the body does the right motor cotex control?

Frontal lobe (though at the far posterior part, i.e. right at the back of the frontal lobe). Right motor cortex controls the left side of the body

Name one famous case study which first demonstrated localisation of function

Tan - Broca's patient with expressive (Broca's) aphasia. Could only say the word 'Tan'. Had damage to Broca's area. OR Phineas Gage. Damage to his frontal cortex and subsequent change in personality suggests there is a causal link between the two (as the frontal lobe controls mood & reasoning). OR H.M. anmesia following removal of the hippocampus - showed formation of long term memories relied on the hippocampus

What is white matter in the brain made up of?

Axons

What is the grey matter in the brain made up of?

Cell bodies of neurons

What is the job of the hippocampus?

Formation and consolidation of new long term memories (and also spatial memory/navigation). Demostrated by e.g. case of H.M., who had his hippocampus removed, and developed anterograde amnesia (inability to create new long term memories)

What was the name of Broca's famous patient

Tan

What evidence suggests that communication may be as important as localisation of function?

Cuomo (2013) - 'The teacher who couldn't read'. Described a case in which the loss of the ability to read resulted from damage to the connection between Wernicke's area and the visual cortex. This suggests that damage to the connection between any two points may resemble damage to a localised brain region.

Who found evidence against localisation of function? How?

"Dronkers et al. (2007). MRI on 2 preserved brains of Broca's patients. Damage in other areas besides Broca's area. Suggests that language and cognition are more complicated and involve networks of brain regions rather than one localised region. OR... Cuomo (2013) - 'The teacher who couldn't read'. Suggested that damage to the connection between any two points may resemble damage to a localised brain region."

What are alternative theories to localisation of brain function?

Network theory (suggesting that networks of specialised areas may be needed to perform complex functions, rather than just single areas). Another is Holistic theory (equipotentiality) - but there is very little support for this

What is a compromise between localisation of function and holistic theory of brain function?

Network theory. Some processes are more localised than others - more complex processes (like learning) involved multiple areas of the brain. Networks needed, not just specialised areas. E.g. Dronkers (2007) or Cuomo (2013)

This term refers to the fact that the left and right halves, or hemispheres, of the brain have centres that are specifically associated with different brain activities, eg speech centres on the left and the ability to make sense of 3D arrangements on the right.

Hemispheric lateralisation

What is hemispheric lateralisation? Give an example.

The idea that certain mental processes or behaviours are controlled or dominantly controlled by one hemisphere rather than the other. Language on the left, facial/object recognition on the right, right controls left side movement, left controls right side movement

What is the corpus callosum?

The band of neural fibres (white matter) that connects the left and right hemispheres of the brain.

What has happened to a split brain patient?

They have had their corpus callosum cut (commisurotomy), usually as a last resort for relieving severe epilepsy.

Why did Sperry make his split brain patients fix their eyes on a dot in the middle of a screen?

To ensure that they are not able to move their eyes. This makes sure that stimuli presented to one side are only processed by one visual field

If an image or word is presented to a split brain patient's right visual field they can...

Name it (verbally)

If an image or word is presented to a split brain patient's left visual field they can...

Draw it or select a matching object from a selection (using their left hand)

If a face is shown to a split brain patient's left visual field...

They can correctly choose the face from a selection

If a face is shown to a split brain patient's right visual field...

They will struggle to identify it

The problems with the split brain research are...

Small sample, Different levels of severing, Varied time since surgery - possibility of some functional recovery? Artificial task - in real life patients can just make use of both eyes à exaggerating the differences

Turk et al. (2002) examined the case study of split brain patient J.W., who showed evidence against lateralisation of brain function. How?

J.W. developed the capacity to speak out of the right hemisphere - he could speak about information presented to the left or right VF (Turk et al., 2002)

What is brain plasticity?

The brain's tendency to change and adapt as a result of learning and experience

What is functional recovery?

A specific type of brain plasticity - occurs following a trauma

Name 3 processes involved in functional recovery. How does each process allow for functional recovery?

Axonal sprouting (growth of new neurons can bypass areas of damage), recruitment of homologous areas (other similar regions of the cortex - e.g. on opposite hemisphere - can take over lost functions), neuronal unmasking (previously 'dormant', unused circuits can be reactivated following damage to the dominant circuits

Why is Maguire et al.'s (2000) taxi driver study evidence for plasticity?

Maguire found significantly more grey matter in the posterior hippocampus of taxi drivers than a control group. Hippocampus is an area important for spatial memory and navigational skills, rso this seems to show plasticity as the brain has changed (increase in size of the hippocampus due to having more grey matter), as a result of the environment (training for 'the knowledge', learning the London street pattern)

What are the 4 ways of studying the brain that you should know?

fMRI, post mortems, EEGs and ERPs

What is an fMRI, what does it measure?

Functional magnetic resonance imaging, measures brain activity using a powerful electromagnet. The magnetic field can detect changes in blood oxygenation (more active areas use more oxygen). This provides a 3D scan of brain activity

A technique of brain-scanning which uses a magnetic field and radio signals to monitor the blood flow in the brain. Areas of the brain that are involved in activities done by the person during scanning have a greater blood oxygenation and flow, so specific brain areas can be linked to specific abilities.

Functional Magnetic Resonance Imaging (fMRI)

What is an EEG, what does it measure?

Electroencephalogram, Uses a net of electrodes placed on the scalp to record the electrical activity of millions of neurons producing brain wave patterns that can be characteristic of specific states/behaviours e.g. stages of sleep

What is an ERP, what does it measure?

Event related potentials. Using the same equipment as for EEGs, but using a statistical averaging techniques on the EEG data to try and isolate specific responses of neurons to specific stimuli or tasks.

Compare an EEG and an ERP

EEG is a recording of general brain activity usually linked to states such as sleep or conditions such as epilepsy, whilst ERPs are elicited by specific stimuli presented to the participant. ERPs involve calculating average neural responses over a long time/many trials. This means all extraneous activity can be removed and responses to the stimulus can be isolated

In brain scanning, what does the term 'temporal resolution' refer to?

Temporal resolution is the amount of time needed to acquire data from the same location (or 'how quickly the technique is able to produce new measurements from the same location?') It is measured as a time (s/ms)

In brain scanning, what does the term 'spatial resolution' refer to?

Spatial resolution is a measure of the smallest amount of space that can be distinguished by the scanning method (i.e. how closely it can 'zoom' in to a specific area). It is measured as a distance (cm or mm)

Compare scanning techniques in terms of temporal resolution

Compared to FMRI, EEG and ERP have HIGH TEMPORAL RESOLUTION. EEG/ERP have a temporal resolution of miliseconds, whereas fMRI has a temporal resolution of seconds

Compare scanning techniques in terms of spatial resolution

Compared to FMRI, EEG and ERP have LOW SPATIAL RESOLUTION. EEG/ERP have a spatial resolution of around 2cm, whereas fMRI has a spatial resolution of as low as 1mm

How do we use post-mortems in psychology?

Compare brains to 'neuro-typical' brains to identify differences and try to correlate these abnormalities to behaviours seen before death.

What are the strengths and weaknesses of using post-mortems as a method of studying the brain?

"POSITIVES - Improve medical knowledge of conditions. Provided a foundation of early knowledge of the brain e.g. Broca's area

NEGATIVES - Ethical issues e.g. informed consent is difficult. Causation is problematic, as the brain may change after death, or the damage in the brain may have occured after the changes in the person's behaviour"

What are circadian rhythms?

Natural cycles that occur once every 24 hours

Give an example of a circadian rhythm.

Sleep-wake cycle, Body temperature

What are infradian rhythms?

Natural cycles that occur less than once every 24 hours (longer cycles)

Give an example of an infradian rhythm.

Menstrual cycle, Seasonal affective disorder

What are ultradian rhythms?

Natural cycles that occur more than once every 24 hours (short cycles)

Give an example of an ultradian rhythm.

Sleep cycle (stages of sleep)

Who first found EEG evidence for the stages of sleep?

Kleitman (1957)

What is brain activity like in each stage of sleep (wave type/speed etc.)?

1 - alpha waves, slower and more rhythmic than when awake, 2 - sleep spindles and theta waves 3&4 - Slow wave sleep - delta waves, slower waves with larger amplitude 5 - REM - activity similar to when awake

What is one way that an infradian rhythm has been found to impact on human behaviour?

Human mate choice varies across the menstrual cycle (Penton-Voak et al, 1999). Women normally prefer a slightly more feminised male face, but when ovulating prefer a more masculine face