Paper 1: Biological approach

Psychology IB paper 1 biological approach SL/HL This flashcard sets contains the SL SAQ content only. APFC stands for Aims, Procedure, Findings and Conclusion.

What is meant by ‘localisation of function‘?

What is meant by ‘localisation of function‘?

The theory that specific parts of the brain are responsible for specific functions

What is equipotential theory?

The theory (opposite of localisation of function) that asserts all areas of the brain are equally active in overall mental functioning

What are the four main lobes in the brain (in the cerebrum)?

Temporal lobe, occipital lobe, parietal lobe, frontal lobe

What is the role of the brainstem?

Controls basic functions such as regulation of breathing and heart rate. It is not usually studied by psychologists.

Temporal lobe

• Hearing, forming sentences, and recognising language

• Contains the hippocampus which is important for the formation of memories

Occipital lobe

• The brain’s major centre for processing visual information

Parietal lobe

• Integrates sensory information, including touch, temperature, pressure and pain

Frontal lobe

• Responsible for higher executive functions such as emotional regulation, planning, reasoning and problem solving

Which study can be used to support localisation of function?

Maguire et al (2000)

Maguire et al (2000) APFC:

A: To compare brains of London cab drivers to brains of non-cab drivers

P: A neuroimaging technique called VBM was used on the 16 cabbies and 50 non-cabbies (all male, healthy and right-handed)

F: Grey matter had shifted from the anterior to the posterior hippocampus in cabbies although overall volume was around the same

C: spatial memory is localised to the hippocampus (can also be linked to neuroplasticity)

In Maguire’s study, what is VBM?

Voxel-based morphometry is a neuroimaging technique (a type of MRI) that investigates focal differences in brain anatomy. Its core process is separating the brain into grey matter, white matter and cerebrospinal fluid, warping the segmented images to a template space and smoothing.

How can Phineas Gage be used as evidence for localisation of function?

• Phineas Gage took an iron rod to the temporal lobe and suffered changes to his personality, becoming unpleasant and impulsive

• This supports the idea of localisation of rational thinking (“system 2“) to the frontal lobe

Define neuroplasticity

The brain’s ability to rearrange the connections between its neurons as a result of learning or experience

Define synaptic pruning

The process by which excess synaptic connections are eliminated so as to increase the efficiency of neural transmissions

What study can be used for an SAQ about neuroplasticity?

Draganski et al (2004)

Dragonski (2004) APFC:

A: To investigate whether learning a new skill could change participants’ brains

P: 24 young male and female volunteers had MRI brain scans. Then half of the participants learned to juggle and they repeated the brain scans 3 months later and another 3 months later when the jugglers had forgotten the skill.

F: Jugglers showed an increase in grey matter in the mid-temporal region and then a subsequent reduction.
C: Juggling relies in visual and spatial memory rather than procedural memory (which would have more likely changed the cerebellum or basal ganglia)

What is an excitatory neurotransmitter?

Excitatory neurotransmitters increase the likelihood of a neuron firing by depolarizing the neuron. Acetylcholine is an excitatory neurotransmitter.

What is an inhibitory neurotransmitter?

Decreases the likelihood of a neuron firing by hyperpolarizing the neuron.

What is an agonist in terms of neurotransmitters?

Agonists are drugs that occupy the receptor site and cause an effect in the next neuron

What is an antagonist in terms of neurotransmitters?

Antagonists occupy the neurotransmitter receptor sites and have no effects themselves on the next neuron. However they prevent receptor activation by agonists.

Which study can be used in an SAQ about neurotransmitters?

Antonova (2011)

Antonova (2011) APFC:

A: To investigate whether blocking ACh receptors would affect spatial memory in humans
P: 20 healthy males were injected with either scopolamine which blocks ACh receptors in the brain, or a placebo. Then they had to do a computer-based spatial memory test called the “arena game“. Repeated 3-4 weeks later with control and experimental group swapped.

F: Significant reduction in activation of hippocampus compared to placebo participants.
C: ACh could be involved in encoding spatial memories.

What were the agonist, antagonist and the target behaviour in Antonova’s study?

Agonist: acetylcholine

Antagonist: scopolamine which blocks acetylcholine receptors in the brain

Target behaviour: memory/learning

What is the role of acetylcholine?

An excitatory neurotransmitter which plays a role in concentration, memory, cognition and muscle function.

What does MRI stand for, and when and who by was it invented?

Magnetic resonance imaging.

The first full-body MRI scan of a human was performed in 1977 by Damadian to diagnose cancer.

What does fMRI stand for?

Functional magnetic resonance imaging

Who invented fMRI and in what year?

It was invented in 1990 by a team of scientists at Bell Laboratories led by Seiji Ogawa

How does fMRI work?

Energy emitted from relaxation of protons is measured and the calculations are aimed at measuring how the level of oxygenated blood supply changes

How does fMRI measure neural activity?

Measuring changes in blood flow is an indirect measure of neural activity

What do the colours on an fMRI scan mean?

Red- the highest level of blood flow, yellow- above average levels of blood flow, green- normal levels of blood flow, blue- below average levels of blood flow

What study can be used in an SAQ about fMRI?

Fisher (2005)

How does Fisher’s study link to the use of fMRI?

Fisher used fMRI to observe activity in the brain.

She saw increased levels of blood flow in the caudate nucleus and ventral tegmental area, indicating a higher level of activity in these areas which are associated with dopamine release.

Which study can be used for the use of kinship/twin studies?

Natsuaki (2005)

Natsuaki (2005) APFC:

A: Investigate the concordance rate of antisocial behaviours in siblings

P: 390 sibling pairs (MZ and DZ twins, half and full siblings, and step-siblings) were measured for antisocial behaviours eg. theft, vandalism and violence

F: Correlation coefficient was highest in MZ twins at 0.59, then DZ (0.21), then full siblings (0.13). Genetically unrelated siblings had a cc of 0.22 but this finding was found to be statistically insignificant.

C: Aggressive behaviour is in part cause by genetics.

What is concordance rate?

The presence of the same trait in both members of a pair of twins.

What is the heritability coefficient?

A score from 0 to 1. A score closer to zero means a trait is less heritable (ie. more due to nurture) and a score closer to one means a trait is more heritable (ie. more due to nature). Aggression is thought to have one of 0.4.

What are hormones?

Hormones are chemical messengers that are secreted into the bloodstream by glands, and they affect specific target cells/target organs (effects can occur over minutes to hours)

Where is oxytocin produced from and where does it act?

It is produced by the hypothalamus and is secreted into the bloodstream by the pituitary gland. It can affect the brain and when it does, it is said to be acting as a neurotransmitter.

Which study can be used in an SAQ about the effect of one hormone on behaviour?

Ditzen (2009)

What are pheromones?

Substances secreted by an individual that can be detected by an individual of the same species via a process similar to smell.

They can communicate messages about things like health, recent diet and place in a hierarchy.

Which study can be used in an SAQ about pheromones?

Wedekind (1995) [See social relationships unit for APFC]

What behaviour did Wedekind investigate?

Mate choice/sexual selection

How do the findings from Wedekind’s study link to pheromones?

The findings suggest that women were able to detect when men had different MHC genes to them via pheromone detection and rated the T-shirts accordingly

Why is the existence of pheromone detection uncertain in humans?

Because humans lack the accessory olfactory bulb and the vomeronasal organ (vno) that is found in some mammals.

What is the role of the MAOA gene?

The monoamine oxidase A gene is responsible for breaking down important neurotransmitters in the brain including serotonin and dopamine

What is the MAOA-L gene?

A variation of the MAOA gene which results in serotonin not being broken down in the brain due to fewer MAOA proteins being produced, meaning that the brain is bathed in serotonin and dopamine= low responsiveness to the effects of these nts

What is the effect of the MAOA-L gene in males?

The first candidate gene linked to antisocial behaviour, thought to cause a predisposition to aggression (nicknamed the “warrior gene“) especially in men

However the effects are only seen when the person has had early-life trauma too.

Which study can be used in an SAQ about genetics?

Caspi et al (2002)

Caspi et al (2002) APFC:

A: Investigate effect of MAOA-L gene

P: Longitudnal study of 1000 children in Dunedin, NZ. They and their teachers/friends/family were interviewed every few years for 25 years. Financial and legal records were used confidentially.

F: Participants with the MAOA-L gene and childhood abuse were more at risk of committing anti-social behaviour/being aggressive compared to MAOA-L gene alone.

C: The warrior gene is more likely to be triggered in those abused/mistreated in childhood.

What is the diathesis stress model?

Diathesis (ie. predisposition or vulnerability)

+ environmental stressor such as abuse or trauma

= aggressive or antisocial behaviour