IB Psychology HL - BLOA - Discuss 2 Effects of Environment on Physiological Processes

dynamic system that interacts with the environment

the brain can determine and change its own behaviour

behaviour and environment can also change the brain

neuroplasticity

nurturing environment increases size of hippocampus (Luby, 2012)

enriched environment increases thickness of cerebral cortex (Rosenzweig and Bennett, 1972)

To investigate the effects nurturing mothers have on the brain development of their children

Experiment conducted with 92 mother-and-child pairs, with children aged 3-6 years

They were left with a brightly-wrapped package that was not allowed to be opened until the mother finished filling out some forms; this was meant to copy the usual stressors of daily parenting

Generally either one of the two things was observed:

- nurturing: mothers offered reassurance and support

- non-nurturing: mothers ignored/scolded the child

Researchers then divided them into two categories (participants were unaware of this)

When the children were 7-10 years old, researchers used MRI to scan their brains

children with nurturing mothers had hippocampi 10% larger than children with non-nurturing mothers

nurturing mothers had a positive impact on the brain development of children

not all variables controlled

non-nurturing mothers may feed their child healthily

the diet may impact brain development as well

to investigate the effect of either enrichment or deprivation on the development of neurons in the cerebral cortex

Placed rats in one of 2 conditions:

- environmentally enriched (e.g. giving interesting toys to play with)

- environmentally deprived (e.g. no interesting toys to play with)

Rats spent 60 days in their respective environments before being dissected

The thickness of each rat’s frontal cortex was measured

post-mortem studies showed that rats in the enriched condition had increased thickness in cerebral cortex

the frontal lobe is associated with thinking, planning, and decision-making

it was found to be heavier in enriched condition rats

evidence of neuroplasticity due to environmental conditions

having interesting toys created the best conditions for developing cerebral thickness of rat brains

tightly controlled study with defined IV/DV

animal study; caution should be used when generalizing to humans

ethically followed the correct guidelines for treatment of animals

rats were bred for experimental purposes and were used sparingly

the brain’s ability to rearrange the connections between its neurons

i.e. redistribute brain mass according to usage/necessity

result of learning or experience

the brain is a dynamic system that interacts with the environment

so the brain can both affect and be affected by behaviour and the environment

Luby (2012): hippocampus is associated with memory and emotion, and a nurturing environment likely correlates to positive emotions

Rosenzweig, Bennet, and Diamond (1972): cerebral cortex is associated with thinking, planning, decision-making, all of which were exercised over the 60 days

general conclusion of the two studies: a nurturing and stimulating environment aids brain development

define neuroplasticity

describe + explain the effects of a nurturing (Luby, 2012) and stimulating (Rosenzweig, Bennet, and Diamond, 1972) environment on neuroplasticity

include background info/reasons for every point

explain why neuroplasticity occurs in the context of those environments

discuss:

give a balanced review with a focus on EXPLAINING EFFECTS rather than EVALUATIONS

state your opinions and give evidence to support them

evaluate all empirical evidence cited (e.g. methodology, ethnics, extent of generalization the results can have)

discuss the usefulness of the findings: mention possible applications and how effective + universal these applications are