Genes vs Environment Flashcards
classic vulnerability framework
Is it that this framework only shows the negative sides of genetic plasticity?
differential susceptibility hpothesis
the differential susceptibility hypothesis states, that people differ in vulnerability towards adversity in their life.
For people with a genetic vulnerability factor, it is more likely to be affected by contextual changes than for people without a genetic vulnerability.
People further vary in how much they are benefiting from supporting environments and rewards.
Scientific support for the differential susceptibility hypothesis:
- 5HTT Serotonin transport gene gene which makes people differentially vulnerable to develop a depression.
- DR4 Dopamine receptor gene
–> modulates experiental and behavioural responses to the environment.
- promoting phenotypic vulnerability for obesity and overeating.
binge eating
binge eating and other disorders that are based on a regulatory dysfunction are based on a reward and self control inbalance in neural circuits.
higher food cue reactivity
less ability to stop impulses
–> due to a sentisation of the dopaminergic mesolimbic system
Study :
people were positioned in an fMRI and were presented with food cues
High caloric foods:
activated regions of reward anticipation (Striatum) and taste representation ( insula) .
- increased activation in ( dorsal striatum, insula, hippocampus) people sufferering from obesity.
integrated model of environmental sensitivity
integrates the diathesis model ( negative) and the vantage sensitivity framework (positive)
for both negative and positive sensitivity
adaptive calibration model
- patterns of individual stress responsibility
environmental layers —> developmental stages
- cortisol - in the mothers blood , sleep behaviour
- mother child bond - insecure attachement
- unhealthy attachement - more mental health and health risks - also more risks of obesity.
- bad parenting is associated with a higher risk of emtional eating.
- parental feeding style- food environment –> strict parenting is maladaptive
- food and community environment / social capita
Extra factors:
socioeconomic status
- gender differences
–> leptin and insulin have a different effect on males and females.
Gender differences in food preferences :
- men prefer a meal
- women prefer to snack
homeostasis vs hedonic hunger
reward deficiency syndrom
hyper sensitivity :
- reward sensitivity.
hypo sensitivity :
one does not feel as much reward compared to other people
appetitive model of obesity
states that obesity is solely a result of appetitive conditioning and does not take into account the genetic component - role of plasticity genes and early enviroment influences on the development.
diathesis stress model
some individuals are more sensitive to negative adverse influences of the environment than others.
sensory processing sensitivity
a persons responsiveness to stress is shaped by the environment they life in.
safe environment = high responsiveness to stress
moderate stress= less responsiveness to stress
high stress environment = high sensitivity vigilant pattern
traumatic stress= no responsiveness
biological sensitivity to context
adaptive calibration model
neuro-sensitivity hypothesis
sensitivity of the nervous system is affected by the environment and genes directly as well as by the interaction between genes and the environment .
plasticity
changes of the genetic phenotype ( cognitive, emotional, behavioural) that are triggered through experiences.
Genes that are differently expressed due to the environment are not called vulnerabilty genes anymore but plasticity genes.
Serotonin 5HT
Dopamine 4R
The Serotonin 5HT gene plasticity is involved in a persons sensitivity towards adversity, punishment and behavioural inhibition.
–> low levels are associated with disorders that lack impulse control. Such as mania and aggression or drug abuse.
Dopamine is associated with guiding human behaviour, reward, motivation, reinforcement and associative learning…
A differential expression of the DR4 Dopamine receptor gene can affect eating behaviour and lead to eating disorders.
Go - no go task
Chikazoe 2017 What does activation in the insula mean?
–> not necessarily connected to pleasure
- biggest activation in the reveresed inhibition task was Disgust.
–> but the disgust might be felt because the task is too demanding.
working memory activation because participants have to sustain the task rules
Participants may have the feeling of sweetness because the gustation of sweetness may be associated with a reward in a gustation task.
Ecological momentary system
differentiating which triggers are especially triggering for specific individuals.
ADHD
ADHD can be linked to obesity because individuals with ADHD have less trait self control and are therefore less able to override there unhealthy impulses.
Empirical study Nederkoorn 2014
How do obesity and impulsivity play a role in the sensitivity to environmental cues?
Assesment of food purchases in an online supermarket.
Condition 1 : Snacks on sale
Condition 2: Snacks not on sale
The persons weight and impulsivity were measured beforehand.
Results:
No effect of price sale on the low weight participants.
Impulsive participants bought more high caloric food than low impulsive participants.
There was an interaction effect found between high weight and highly impulsive participants. –> advertisement was effective for these participants.
The combination of a food reward and high impulsivity makes ( obeses) people more vulnerable for their environment.
behavioural Susceptibility theory ( obesity)
Tries to find the mediating traits to link genes and behaviour.
Appetitive traits:
on set and off set
on set ( high sensitivity)
–> how reponsive are you to food cues
off set ( low inhibition)
–> how able are you to stop?
mindset is important
