Biological

Question 1

Structural imaging MRI

Voxel-based morphometry (VBM)

Pixel counting

Answer 1

magnetic resonance imaging, giant circular magnet, based on principle that protons (hydrogen atoms) can emit energy when placed in external magnetic field. Hydrogen atoms exist naturally in body but concentration in different types of tissue varies. MRI produces magnetic field, protons align with field. Radio signal produced disrupts hydrogen atoms’ alignment. When radio signal turned off, atoms returned to original position in magnetic fields, atoms realign, which produces energy. MRI detects energy, allows differentiation of tissues and organs.

VBM: uses statistics to identify differences in brain anatomy based on density of grey matter
PC: counting pixels in MRI images, two dimensional measurement of area

Question 2

Functional imaging MRI

Answer 2

magnetic resonance imaging, giant circular magnet, slide in. Neurons in brain more active cause capillaries around to dilate + bring more blood and oxygen to neurons. Within red blood cells, O carried by haemoglobin . Haemoglobin releases oxygen, becomes deoxyhaemoglobin. Deoxyhemoglobin more affected by magnetic field than oxygen-rich haem. Contrasts in blood-oxygen response allow for map of brain activity with fMRI.

Question 3

fMRI/MRI S+L

Answer 3

Strengths
Non-exposure to radiation
High resolution, useful for detecting abnormalities in soft tissue of brain
Able to detect brain activity while performing action (with restriction of machine)
Limitations
No metal in body allowed + Noisy + Expensive
Issues with claustrophobia - Must lie still for 40 mins
Produces artificial environment - ecological validity decreases.
Indirect measures of brain activity as measuring the blood oxygen rather than neurotransmitters themselves - assumptions must be made.
Artefacts can affect brain scan (activity in the brain due to something other than what is being investigated (e.g. anxiety in an fMRI)

Question 4

Study: Antonova

Answer 4

Aim: To investigate role of neurotransmission on spatial memories.
Procedure: Male adults. Souble-blind procedure and participants were injected with either scopolamine (an antagonist of acetylcholine, neurotransmitter found in hippocampus) or placebo before experiment. Participants were placed into fMRI while playing virtual reality game where they had to navigate around virtual arena to reach pole. After they successfully located pole, screen went blank for 30 seconds, while participants were told to rehearse route to pole. When screen turned back on, participant was placed in different starting position and they had to use spatial memory to find location of pole. Participants redid experiment 3-4 weeks later, with opposite condition/injection.
Results: Researchers found that participants injected with scopolamine showed significant reduction in activation of hippocampus compared to when they received placebo. Acetylcholine receptor sites are highly concentrated in hippocampus.
Link to techniques: Through technological technique of fMRI, Antonova was able to compare and determine role of hippocampus in spatial memory, and in particular, importance of acetylcholine in encoding and retrieval of spatial memory.
Link to neurotransmission: Therefore, this demonstrates that neurotransmission of acetylcholine could play important role with encoding of spatial memories in humans.
Link to localisation:

Strengths
Repeated measures design - reducing effect of participant variability.
Counter-balanced - some did scopolamine condition first, others did placebo first. Controlled for practice effect.
Double blind; this controls for demand characteristics and researcher bias.
Limitations
No significant difference in rate of error. However, difference in hippocampus activity = significant. Task designed may not have been best for showing performance differences; without fMRI, no way to know biological level significant differences in two conditions.
In debriefing, many participants said they had felt stressed, either due to injection or fMRI. Could have effect on working of hippocampus; we know that stress may interfere with memory encoding.
Sample size = small. Need replication for reliability.
Sample = all males, low generalisability to females

Question 5

Localisation of function

Answer 5

Argues that different parts of brain have different functions which play role in behaviour.

Question 6

Neuroplasticity

Answer 6

Brains ability to change in response to experience, learning or injury

Question 7

Neural network

Answer 7

series of connected neurons that allows processing and transmitting of information. Specific networks are responsible for specific tasks

Question 8

Neural pruning

Answer 8

Synaptic pruning can be studied by observing loss in grey matter density in brain via MRI. Grey matter consists of cell bodies, dendrites and synapses. More grey matter, more synaptic connections and neural networks. Loss of neural connections due to disuse. Especially true for adolescents (teenagers) because synaptic pruning occurs mostly during this stage

Question 9

Study: Maguire (2000)

Answer 9

Aim: To investigate whether brains of London taxi drivers would be somehow different as result of their training and extensive use of spatial memory.
Procedure: Participants were right-handed male London taxi drivers. London taxi drivers train so that they know whole map of London and every possible route. MRI of taxi drivers was compared to control MRI of right-handed males (not taxi drivers), which was taken from MRI database. Research used single-blind procedure, where researcher did not know whether she was looking at scan of taxi driver or control. Data from MRI was measured using voxel-based morphology (VBM), to measure differences in density of grey matter of brain, and pixel counting, counting pixels in order to calculate area of hippocampus.
Results: Through pixel counting, Maguire discovered that posterior hippocampus of taxi drivers was significantly larger relative to those of control subjects and anterior hippocampus was significantly smaller. VBM showed that volume of right posterior hippocampus correlated with amount of time spent as taxi driver.
Link to techniques: Through technological technique of MRI, Maguire was able to compare brains of London taxi drivers and non-taxi drivers to discover that posterior hippocampus plays key role in spatial memory and navigation. Psychologists investigating localization of brain function from biological approach use brain-imaging techniques to investigate correlation between brain processes and structures and human behaviour.
Link to neuroplasticity: Through technological technique of MRI, Maguire was able to compare brains of London taxi drivers and non-taxi drivers to discover that posterior hippocampus plays key role in spatial memory and navigation. Psychologists investigating localization of brain function from biological approach use brain-imaging techniques to investigate correlation between brain processes and structures and human behaviour.
Link to localisation:

Strengths
High ecological validity - taxi drivers continue doing their driving and normal day-to-day activities, MRI just takes snapshot of their brain
Controlled quasi-experiment, decreases confounding variables, clear cause and effect relationship. Bidirectional ambiguity removed, volume of posterior hippocampus correlated with time spent as taxi driver.
Single-blind procedure, researcher did not know whether looking at scan of taxi driver or control, reduces researcher bias.
Mean age, handedness and gender of both groups were same, reduces participant variability.
Limitations
Low generalisability to women taxi drivers - sampling bias
MRI scans of control group were used from MRI database of London hospital which raises ethical concerns regarding informed consent in use of data.
Small sample size of 16 taxi drivers which leads to low validity of results.

Question 10

Study: Draganski et al

Answer 10

Aim: To investigate whether learning new skill would have effect on brains of participants.
Procedure: All participants = non-jugglers at start of study. Each participant had MRI scan at start of study. Participants randomly allocated into two conditions (juggling and non-juggling), independent samples design. Juggling group taught juggling routine, after mastering it, they would undergo second MRI scan. After scan, they were told to not juggle for 3 months; third scan was carried out 3 months later. Non-juggling group served as control group. To analyse MRI scans, researchers used voxel-based morphometry (VBM) to determine if there was significant difference in neural density (grey matter) in brains of jugglers and non-jugglers.
Results: From baseline scans, they found no significant regional differences in grey matter between two conditions. However, jugglers showed significantly larger amount of grey matter in mid-temporal area in both hemispheres - area associated with visual memory. 3 months after participants stopped juggling, amount of grey matter in these parts decreased. No change over duration of study in no juggling sample.
Link to neuroplasticity: It appears that juggling relies more on visual memory, perception and spatial anticipation of moving objects, than on procedural or motor memories that would more likely show change in cerebellum or basal ganglia.
Link to techniques:
Strengths
Although independent samples design, three separate brain scans taken to show effect of learning juggling on brain for each juggling participant, allowing each brain scan to be compared to brain scans of each participant separately.
True experiment w controlled variables, clear cause + effect relationship.
High ecological validity, participants did day-to-day activities + people would learn to juggle in real life, MRI was just used to take snapshot of brains.
Limitations
Independent samples design, participant variability as participants’ data is compared to that of other participants.
Small sample size (24), decreased validity of results.
Sample of adults aged 20-24, low generalisability to other age demographics
Juggling condition not watched over three months told not to juggle, researchers cannot be certain that they did juggle.

Question 11

Neurons

Answer 11

send electrochemical messages within nervous system to brain so that people can respond to stimuli.

Question 12

Neurotransmission

Answer 12

process of communication of neurons around body. The communication between neurons occurs at synapse, where neurons are separated by microscopically small synaptic cleft. The signal is initiated by axon terminal of presynaptic neuron, and received by postsynaptic neuron. In presynaptic neuron, chemical signals/neurotransmitters are packaged into small sacs called vesicles. Presynaptic neurons, excited by electrical impulse/action potential, release neurotransmitters into synaptic cleft. The neurotransmitters interact and bind to receptors of dendrite like ‘lock and key’.
Neurotransmitters or drugs may be excitatory (activate neuron) or inhibitory (prevent neuron from firing and passing signal)

Question 13

Agonist

Answer 13

binds to receptor site and mimics actions of neurotransmitter whose receptor sites it’s binding to.

Question 14

Antagonist

Answer 14

binds to receptor and then stops that neurotransmitter from binding and sending signal.

Question 15

Study: Rogers & Kesner

Answer 15

Aim: To investigate role of acetylcholine, neurotransmitter found in many animals including rats and humans, in formation and retrieval of spatial memory.
Procedure: Researchers had 30 rats placed into Hebb Williams maze, with food in one of corners. The rats first familiarised themselves with maze so that they would not feel scared. The independent variables were two conditions that rats were subjected to, either injected with scopolamine or saline solution directly into hippocampus 10 minutes before doing maze. Scopolamine (an antagonist of acetylcholine) blocks acetylcholine receptor sites and inhibits any response. The encoding of memory was assessed by average number of errors made on first five trials of Day 1, compared to last five trials of Day 1. Whereas retrieval of memory was assessed by comparing average number of errors on last five trials of Day 1 with first five trials of Day 2. The time they took to complete maze was also recorded.
Results: The researchers found that group injected with scopolamine took longer and made more mistakes in learning maze; they had higher average number of errors in last five trials of Day 1. The scopolamine did not appear to affect retrieval of memories; average errors for first five trials of Day 2 were similar for both groups.
Link to neurotransmitters: Therefore, due to scopolamine negatively impacting encoding and consolidation of spatial memories, it can be concluded that acetylcholine and neurotransmission may play important role in consolidation of spatial memories.

Strengths
Rigorously controlled experiment with placebo condition to avoid effect of confounding (extraneous) variables.
The study is able to establish cause and effect relationship;
The research could one day lead to development of treatments for people suffering from dementia or Alzheimer’s disease.
Limitations
Reductionist approach to understanding memory. Several different types of memory and process of memory consolidation is very complex.
Biologists believe that animals can serve as models for human physiology and behaviour; however, there are questions about extent to which findings can be generalized to humans

Question 16

Hormones

Answer 16

chemical messengers in body, released by glands in endocrine system into bloodstream to various tissues and organs, regulates long-term ongoing changes such as growth, digestion etc.

Question 17

Cortisol

Answer 17

‘stress’ hormone produced in adrenal glands, increases glucose in blood and increases metabolism of fats, proteins and carbohydrates. It provides energy in ‘fight/flight response’ allowing body to stay on high alert.

Question 18

Study: Newcomer et al (1999)

Answer 18

Aim: To investigate whether high levels of cortisol would interfere with verbal declarative memory (memory of facts, knowledge and events).
Procedure: A double blind laboratory experiment with matched pairs design of age and gender in one of three conditions. In all three conditions, tablet was given to participant each day over four-day experiment.
In high cortisol level condition, tablet contained 160mg of cortisol (similar to cortisol levels in people experiencing major stress event).
The low cortisol level condition, tablet contained 40mg of cortisol (similar to cortisol levels in people experiencing low level stressor).
The third condition was placebo group, given tablet which looked like other tablets but did not have any active ingredients.
All participants were asked to listen to and recall parts of prose paragraph. This tested their verbal declarative memory before tablets were given and then over period of four days.
Results: The results indicated that high cortisol levels impaired performance in memory task since participants who received highest level of cortisol showed worst performance in memory task. The effect was not permanent. The performance in high cortisol condition returned to similar levels as placebo after they stopped taking hormone tablet.
Link to hormones: This indicates that there is clear link between hormone, cortisol, and behaviour of memory. It appears that high levels of cortisol interfered with recall of prose passage, whereas low cortisol levels may have assisted in recall of passage. This makes sense as there are cortisol receptor sites on hippocampus, which is responsible for transfer of information from short term memory storage to long term memory store.

Strengths
establish clear cause and effect relationship
researchers carried out baseline test to eliminate possible confounding variable of individual differences between groups
Different texts days 1 and 4. Counterbalanced texts to act as control so difficulty of text did not play role in recall.
Ethical considerations: participants ingested cortisol which affected memory negatively. However, participants had signed informed consent form and damage was not permanent.
Limitations
Several days and participants not in lab whole time, not full control over extraneous variables - individual stressors in participant lives. Clear relationship between cortisol ingested and performance on memory test.
Memorising prose = not most authentic memory experience. May explain student exam stress, limited generalisability.

Question 19

Study: McGaugh & Cahill

Answer 19

Aim: To study role of emotion in creation of memories.
Procedure: OG flashbulb exp. but participants in “traumatic story” condition injected with either beta-blocker called propranolol which is antagonist that blocks hormone adrenaline or placebo. Drug that is used to treat heart disease because beta-blockers block target cells for adrenaline so that heart will pump more slowly and efficiently. However, in this study, it was used to prevent activation of adrenaline in amygdala.
Results: The researchers found that participants who had heard more emotionally arousing story demonstrated better recall of specific details of story. They could also recall more details from slides. In follow-up study however, those that had received beta-blocker did no better than group that had heard “boring” story. They, therefore, concluded that hormone adrenaline plays significant role in creation of memories linked to emotional arousal.
Link to localisation:

Strengths
cause-and-effect relationship
easily replicated because of its standardised procedure, increases reliability of results
significant difference between total recall of participants in different test conditions, so study demonstrates internal validity
applied to treatment of PTSD patients
Limitations
Artificial in nature and highly controlled, low ecological validity
Unlikely to be quizzed about slides
recognition task had three options = not valid test of memory.

Question 20

Pheromones

Answer 20

‘ecto-hormones’, chemical messengers that are emitted into external environment from body where they can then activate specific physiological or behavioural responses in other animals, and theorised to also be in humans.

Question 21

Attraction

Answer 21

interest in and liking of one individual over another

Question 22

Sexual selection

Answer 22

choosing best mate to reproduce most healthy offspring

Question 23

Pheromones S+L

Answer 23

Strengths: Could be explanation for mate selection
Limitations: Research tends to have small sample sizes. Inability to eliminate effect of other variables that may influence human scent. The human process of scent detection is very complex and difficult to measure.

Question 24

Study: Thorne and Naeve

Answer 24

Aim: To investigate role of pheromones on female ratings of male attractiveness.
Method: Female undergraduate students were selected for study via opportunity sampling. Half participants were contraceptive pill users. The participants came to laboratory on two separate occasions based on menstrual cycle phase. During both lab visits, participants were asked to rate attractiveness of male faces. A counter-balances, repeated measures design was used where experimental conditions were involved exposing females to male axillary secretions, sweat from underarms of men, thought to be pheromones.
Results: There was significant positive correlation between exposure to male axillary secretions and ratings of attractiveness. This means that participants were more likely to highly rate faces when exposed to secretions. There was no effect of menstrual cycle or contraceptive use on ratings of attractiveness.
Link to pheromones: Exposure to natural male axillary pheromones can significantly enhance female perceptions of various aspects of male attractiveness, indicating link between pheromones and mate selection.

Strengths
Supports other pheromone studies
Limitations
Prone to false positive

Question 25

Study: Wedekind et al

Answer 25

Aim: To investigate whether one’s MHC would affect attraction and mate choice.
Procedure:
Female and male participants were tested+sorted into different types of MHC.
Male participants given clean cotton t-shirt to be worn and asked to keep in open plastic bag when not wearing.
Given perfume-free detergents and perfume-free soap. Asked to not use anything or do activities that may affect smell of t-shirts.
Women tested second week after beginning of menstruation as women appear to be most odour-sensitive at this time.
T-shirts placed into seven boxes depending on MHC type, hole for women to smell odour. Three boxes with t-shirts MHC similar to women’s own, three with t-shirts from MHC dissimilar men, and one contained unworn t-shirt as control. Individually scored odours of t-shirts for intensity (0-10) and pleasantness/sexiness (1-10, 5=neutral).
Results+link: Women scored male body odours as more pleasant when differed from their own MHC, supports theory that one’s MHC genes affects attraction and may play important role in mate selection.
Strengths
Supports evolutionary argument for mate selection. Successfully replicated + showed this to be case for male mice, which show preference for females of different MHC.
Research shows couples who suffer from repeated miscarriages and newborn with reduced mass often share higher proportion of MHC than control couples. -> Ability to detect MHC could play key role in search for “best mate”
Double-blind = minimize demand characteristics.
Ethical standards as consent obtained from participants debriefed.
Limitations
Reductionist, over-simplifies mate selection by bringing it down to MHC – ignoring cognitive/sociocultural factors.
Sample not considered representative as participants were similar in age and culture

Link: Individuals want to choose the best mate in order to have healthiest offspring

Question 26

Genes

Answer 26

made up of DNA that provides blueprint for structure and function of human body, including behaviour. An individual’s genome refers to all genes that individual possesses.

Question 27

Gene regulation and gene expression

Answer 27

Not all genes individual possesses are expressed at all times. Genes can be switched on and off. Gene regulation resulting in differential gene expression. Therefore, having gene for particular behaviour does not necessarily mean that individual will exhibit that behaviour.

Question 28

Study: Caspi et al. (2003)

Answer 28

Aim: To investigate role gene mutation and epigenetics may play in major depressive disorder
To investigate whether functional change in 5HTT gene is linked to risk of depression in individual
Procedure: Opportunity sample from cohort of participants from anorlongitudinal study. 847 26-year-olds, 3 grups depending on length of their allele on 5HTT transporter gene. 2 short, 1 long 1 short, or 2 long alleles.
Stressful life events between 21 and 26 birthday assessed using life-history calendar.
Past year depression assessed using Diagnostic Interview Scheudle.
Correlation tested between stressful life events and depresion, between allele length and depression, and interaction between perceived stress and allele length.
Futher test done to see life events could predict increase in depression over time among participants with 1 or 2 short alleles.
Results: Participants with 2 short alleles in 5HttPR gene reported more depression symtoms in response ot stressful life events than either of other groups. Long allele participants reported fewer depression symptoms. Childhood maltretament predictive of depression in adulthood only in adults with either 1 or 2 short alleles.
Link to genes: No direct relation between short alleles on 5HTT gene and depression, relationshop between these and incidences of stress and usbsequent depression. Long alleles protected againsts suffering depression as result of sress. Effects of gene adaptation and expression dependent on evironmental exposure to stress.

Strengths
Large sample size
Age controlled to isolate variable of number of stressful life events between ages 21 and 26
Natural experiment (IV = length of alleles)
Limitations
Gene action = complex, actions of other genes not controlled
Stressfulness=subjective/personal whether participants marks event as stressful or not
Symptoms of depression self-reported (one colleague contacted to verify), can be unreliable

Question 29

Study: Meyer-Lindenberg et al.

Answer 29

Aim: To see how differences in MAOA gene (high expression vs. low expression) affects brain activity when exposed to threat (MAOA: codes breakdown of important neurotransmitters like serotonin and dopamine)
Procedure: Participants were in one of two conditions: they either had the MAOA low expression gene (MAOA-L) or high expression gene (MAOA-H). The MAOA gene was thought to be linked with aggression. Their brain volume was measured using an MRI. The participants were placed in fMRIs to see brain activity while viewing angry or fearful faces (emotional stimuli).
Results: MAOA-H participants had increased volumes of grey matter in the amygdala. Activity in amygdala was higher in MAOA-L participants than MAOA-H ones while perceiving the angry or fearful faces. However, activity in the prefrontal cortex was lower in MAOA-L participants than MAOA-H ones when perceiving emotional stimuli. Prefrontal cortex is important for inhibiting impulsive behaviour. Reduced activity in the PFC may result in a threatened individual acting aggressively on impulse. The chances of this behaviour are increased with the higher activity in the amygdala, since activity in their amygdala is associated with high levels of emotion and arousal, which are important components of anger and aggression.
Link to genes: This shows that the MAOA gene expression may play an important role in the behaviour of aggression as it can lead to increased chances of brain activity related with aggression.
Strengths
Large sample size (142)
Natural experiment, high ecological validity
Limitations
Gene action = complex, actions of other genes not controlled
Maybe another cause of activity eg. being in fMRI

Question 30

Genetic similarities

Answer 30

use of people with similar genes in research. These are used as variables in studies on relative effect of genes on behaviour (e.g. heritability).

Question 31

Kinship study

Answer 31

Studies about family and their genetic similarities.

Question 32

Study: Weissman et al (2005)

Answer 32

Aim: To investigate potential genetic nature of Major Depressive Disorder.
Procedure:
Longitudinal family study over 20 years for high and low risk for depression
Original sample of depressed patients (first generation, now grandparents) and non-depressed participants selected from same community.
The original patients and their children (second generation) interviewed 4 times during period. Children have had children, allowing for study of third generation.
Data was collected from clinicians, blind to past diagnosis. Researcher triangulation used: children evaluated by two experienced clinicians. The inter-rater reliability (similarities between two clinician’s evaluations) of their diagnoses=very high.
Results: Higher rates of psychiatric disorders in grandchildren with two generations of major depression. Children had increased risk of any disorder if depression was observed in both previous generations. Severity of parent’s depression correlated with increased rate of mood disorder in children. However, if parent was depressed without history of depression in grandparents, no significant effect of parental depression on grandchildren.

Question 33

Evolutionary explanation of behaviour

Answer 33

Explaining how behaviour helps individual to pass on their genes by helping them to survive, procreate and/or produce healthy offspring (children).

Question 34

Major Histocompatibility Complex

Answer 34

group of genes which make molecules that enable immune system to recognise pathogens; more diverse MHC genes of parents, stronger immune system of offspring. MHC genes expressed co-dominantly (inherited alleles from both parents and are expressed equally). Therefore, it is beneficial to be able to recognise immune systems with different MHC genes to maximise offspring’s immune response. Evolutionary psychologists argue that our ‘smell’ is sign of MHC.