Child - Bio - Topic 1 & 2

Intelligence and Pre-adult Brain Development

Topic 1 - Intelligence

What psychologists mean by intelligence and what bio factors could affect intelligence

Van Leeuwen - twin family study of general IQ

One method of assessing intelligence

Bio assumptions

The mind resides in the physical structures of the brain and so all thoughts, feelings, emotions ultimately have physiological cuase

Behaviour is caused by our biology and the way or body works - “All that is psychological is physiological”

BR- Spearman

1904

Our cognitive ability is what we might commonly call our intelligence

BR- Sternberg

Triarchic theory of intelligence/Theory of Successful Intelligence - based on three forms of intelligence: analytical, practical, creative.

Constructed the Sternberg Triarchic Abilities Test (STAT) to assess ^

BR- Cattell

Over 100 skills which someone uses when they are planning what to do - can be considered as intelligence.

Intelligence is what you do when you do not know what to do.

Fluid and crystallised intelligence.

Fluid intelligence

Biological and innate ability which doesn’t change (static)

Crystallised intelligence

What we learn or develop (knowledge that we have taken in and used)

Tested by IQ tests which assess knowledge, use of language. acquired skills.

BR- Horn

Researched 14-61 year olds

Found fluid intelligence tended to be higher for younger adults than older adults

Crystallised intelligence generally higher for older adults than younger adults.

Fluid intelligence lost with age, crystallised intelligence increase

BR- Gardner

Theory of multiple intelligences

Intelligence cannot be measured by single IQ test - more complicated

Idea of mathematical and linguistic, musical, spatial, kinesthetic intelligences and others

What biological factors could affect intelligence?

• Genetics

• Environmental Biology

• Brain size

BR- Genetics - Plomin and Defries

Found identical twins who were raised in raised environments had scores of significantly greater similarities than the scores of non-identical twins raised in shared environments.

Even when reared apart, identical twins have greater similarity than non-identical twins who were raised together.

Contribution of genetics to intelligence 25-50%

BR - Environmental - Lucas

Found premature babies who were breast fed had higher IQs than those who were bottle fed

BR - Environmental - Schoenthaler et al.

Researched children 9-12 who did not have nutritious diet and who had low IQ

IQ score improved when vitamin supplement given

BR - Brain size - 19th century scholars

Studies indicated people with a larger head were more intelligent - small correlation between intelligence and head size.

Difference in brain size between males and females indicated males were more intelligent than females.

Van Leeuwen - Aim

To investigate intelligence using a study in twins, their siblings, parents to assess the relationship between family members and IQ

Van Leeuwen - Sample

112 families used from Netherlands

MZ or DZ twins, siblings 9-14

Families all had 2 parents

Only included families whose children were without self-reported psychiatric problems, mental illnesses, other disabilities

No significant educational level differences of mothers compared to rest of population

Van Leeuwen - Design

Research article/paper which focuses on a correlation study with extended twin design

Van Leeuwen - Procedure

Families provided DNA via cheek swab to check whether the twins were identical. Members had MRI scans on brains to provide extra data

All children completed IQ tests individually in separate rooms - SPM test. No time limit. Given verbal instructions. Range of cognitive tasks - identifying missing puzzle piece to completing analogies.

All parents completed APM test. Given written instructions. Questions became progressively more difficult.

Van Leeuwen - Retest reliability for SPM and APM

SPM - +0.88

APM - +0.91

Van Leeuwen - Results

Correlation of IQ scores higher in MZ twins than DZ twins

No statistically significant gender differences

Correlation of IQ level between couples WAS significant (+0.33) - suggests individuals are more likely to mate with people of a similar intellectual ability

Suggests genetics account for 67% of intelligence

Van Leeuwen - Conclusions

Main influence of IQ = genetic factors BUT genes do interact with environmental factors to influence intelligence levels in significant ways

Suggests environment is relatively more important in explaining individual differences in low IQ families than high IQ families

Applications/IQ tests - Raven’s Progressive Matrices

Nonverbal test - does not rely on language - instructions for test can be provided orally - neutrality in terms of culture

Research: Used in Van Leeuwen’s study and informed by Cattell- assesses fluid intelligence

Describe: Number of incomplete, novel, pictorial patterns and each p must complete by selecting missing design from group of possibilities

Items get progressively more challenged throughout - reflected in calculations

Once a score is generated, it can be compared to average score from the same age

3 versions of Raven’s Progressive Matrices

Colour Progressive Matrices - CPM - 4-7yo, the elderly, groups with mental difficulties - 36 items - mostly colour.

Standard Progressive Matrices - SPM - 7-18yo - 60 items in black and white

Advanced Progressive Matrices - APM - Adults 18+ - 48 items

Applications/IQ test - The Goodenough Harris Drawing Test

Developed in 1926. Deviated from standard IQ tests - involves assessing intelligence based on drawings rather than logic.

Research: Informed by Gardner’s research - focuses on understanding of visual spatial skills as standard measure of intelligence

Children asked to draw a man, woman, and themselves.

Drawings analysed in terms of features, levels of detail, proportion. System analyses 14 different aspects of the drawings (specific body parts + clothes) for various criteria like presence of detail and proportion.

Eval: BUT concurrent validity questionable, cannot provide quantitative IQ score BUT could be used alongside other measures

Topic 2 - Pre-adult Brain Development

Brain development and the impact of this on risk taking behaviour

Neural representation of expected value in the adolescent brain

At least one strategy to reduce risk taking behaviours using knowledge of brain development

BR- Most brain structure development occurs when?

First 3 months of life and continues through early infancy at an astounding rate

BR- Which areas of the brain are not at peak maturation until adolescence and adulthood?

The limbic system - responsible for social info, emotional behaviour, formation of new memories

The cerebral cortex - associated with high level reasoning, decision making

BR- When do certain behaviours develop?

Infantile grasping/blinking to light - Birth - Cerebellum and Occipital lobe developing

Able to identify shapes - 2 ½ - 3 years - Parietal lobe

Able to talk and have a conversation which makes sense - 3 years - Temporal lobe

Understand what is right/wrong and able to follow rules (morality) - 4 - 8 years - Frontal lobe

Able to understand wider principles of morality and universal ethics in decision making - 14 - 18 years - Frontal lobe

BR- Regions of the brain and their functions

Frontal lobe - decision making

Parietal lobe - assists with interpretation of touch, understanding of objects, shapes, space

Occipital lobe - processes visual information

Temporal lobe - perception of sound, recognition of objects and visual memory

Brainstem - transfer of info between brain and body, role in automatic functions like heartbeat + breathing

Cerebellum - major role in balance and voluntary motor skills

BR- White/Grey matter

Adolescence - grey matter reaches peak volume

Grey matter: made up of nerve cell bodies, makes up 40% of adult brain, processes info

White matter: made up of neurons with long axons that carry messages to and from grey matter areas, between grey matter and to other parts of body

Brain eliminates unused neurons- allowing brain to use its energy supply more resourcefully

BR- Epstein

Brain weight at birth = 350 grams

Brain weight at 2yo = 1000 grams which is 75% of adult brain.

BR- Myelination

Process insulates neurons, enables them to conduct electrical impulses more easily within the nervous system.

Carries on into adolescence but mostly occurs in the first few years of life

At birth, a baby’s nerves will not have a mature myelin sheath which results in uncoordinated and awkward movements. As the child develops, myelin sheaths develop and movements become smoother and more co-ordinated.

BR- Synapse Pruning

In infant’s brain, x2 as many synapses as there are in adults brain.

3yo - Synapse Pruning occurs

Synapse connections that are not being used will die off, leading to greater organisation within the brain so that areas become specialised for certain functions.

Continues throughout entire duration of brain development.

BR- Examples of risk-taking behaviour that adolescents are more prone to

Unprotected s3x, drug use, situations that could cause injuries of accidents, reckless driving

BR- The perfect storm

Underdeveloped Prefrontal Cortex - will not reasonably assess the consequences

Matured ventral Striatum- highly sensitive to rewards/gratification, leads to sense of independence and novel adult-like activities

Extremely active Limbic System- teenagers are dominated by emotions rather than reason/logic when making decisions

Leads to time of risk-taking behaviour for adolescents

BUT environment aspects too - drinking to ease insecurity

BR- Problems with neurochemicals such as serotonin

Research into monkeys- Reduction in serotonin, seen in situations where the offspring has been subjected to stress as a baby, can lead to impulsivity

Suggests children who suffered stressful infanthood may have lowered levels of serotonin and increased impulsivity

Mix of environmental factors and biological factors

Barkley-Levenson and Galvan- Aim

Aim was to identify if there is a difference in neural activity between adolescent and adult brains when given risk-taking scenarios (gambling).

Barkley-Levenson and Galvan- Sample

19 adult p’s (8m:11f) - mean age = 27.9

22 adolescents (11m:11f) - mean age = 15.6

USA, University of California Campus

All healthy (mental and neurological illnesses were also checked), right handed

Volunteer sample- recruited from advertisements on posters and the internet

FINAL NO. OF P. = 20 adolescents, 17 adults

Barkley-Levenson and Galvan- Design + Method

Quasi experiment conducted in a lab

Independent measures

IV- naturally occurring - adult or adolescent

DV- performance on simple mixed gambles game, VS activity during brain scan by fMRI

House Money Effect

Gambling term - suggests people are happier to take bigger risks when the money they are playing does not belong to them

Barkley-Levenson and Galvan- Procedure 1 (Intake Session)

Collected info of each p’s amount of spending money per month before experiment - mean for adolescents = $52, mean for adults = $469

Familiarised top fMRI environment with mock scanner

P’s given $20 as “playing” money during fMRI task, told they had opportunity to win another $20 but also a possibility to lose this $20 during the gambling task.

Barkley-Levenson and Galvan- Procedure 2 (Gambling task)

1 week after pre-experiment session

P’s presented with series of gambles - each with 50% probability of gaining the amount shown on one side of the “spinner” and 50% probability of losing the amount shown on the other side

Range of profit values - +$5 and +$20, -$5 and -$20

Total of 144 trials

24 gain only trials, 24 loss only trials

Either accepted or rejected each bet based on the Expected Value

Differences in brain activity would reveal if adolescents and adults consider risk differently, how the amount of risk might affect the level of brain activity

Barkley-Levenson and Galvan- Results

Both groups accepted the gamble when the expected value was positive rather than zero

The higher the expected value of a win, the more likely the adolescents to accept the gamble compared to the adults

Left VS activity was significantly greater in the adolescents than adults, activity increased as the expected value rose

Adolescents and adults behaved similarly when there was no risk involved in the gambles

Amount of disposable income did not have an effect

Barkley-Levenson and Galvan- Conclusions

Adolescents are more likely to engage in advantageous risk-taking. No significant differences when risks are not present

Significant developmental differences found in VS- adolescents showing much greater activation in VS than found in adults

Adolescents place greater value on rewards than adults - increases risk of high stakes behaviour

Applications - Graduated Driver Licensing Schemes (GLS)

Informed by Barkley-Levenson and Galvan- adolescents are more likely to engage in risk-taking behaviour due to their lack of cognitive control

Therefore, adolescents more likely to drive in riskier manner than adults, more accidents.

Describe: GLS involves withholding a full driving license from adolescents until they have successfully passed a probationary period

Explain how to implement: Several restrictions imposed on younger drivers below 21 to limit their need to make cognitive decisions. This could include: no night time driving 10pm-5am, maximum speed limits, zero blood alcohol, limited number of passengers. Monitor this with a black box - to limit speed.

Eval: Optimistic, easy to implement BUT less generalisable due to ind. char., reductionist, socially sensitive

Applications - Parenting Strategies

Informed by Newman’s research- adolescents who are brought up in authoritative families have consistently shown fewer risk behaviours than those categorised as being from non-authoritative families.

Authoritative families: high expectations, heavily punished.

Their disapproval of early sex has been positively correlated with delayed initiation and future development of STI’s

Describe: Adolescents with authoritative parents who have positive relationships and open communication and perceived parental support are significantly less likely to develop risk-taking behaviours

Explain how to implement: Parents need to discipline their kids when they engage in risky behaviours (Operant conditioning) so they are less likely to repeat risky action. Parents should model (SLT) positive non risky behaviours. BUT parents should not be so authoritative so as to prohibit healthy relationships and limit communication to avoid simply delaying risky behaviours or leading to lack of support when things go wrong.

Eval: Easy to set up parenting class - but ind. diff. the parents need to be engaged in it, parents don’t want to hear they’re doing bad job