Psychobiology Flashcards
2 aspects as to the importance of studying self control
The personal and societal costs of failures at self control eg addiction, debt..
It predicts positive life outcomes (mental health, decision making, relationships..)
Key words in defining self control
Resisting and overriding impulses, temptation
automatic, habitual behaviours
that interfer with goal directed behaviour
to be consist with long term goals
What is the difference between top down and bottom up processing and
Top down processing:
Rational, abstract goal directed behaviour and processing of information.
Bottom up processing:
Emotionally triggered, reflexive behaviourInvolivng primitive strucutres such as amygdala,
What areas of the brain top down and bottom up processing take place?
Top down processing involves cerebral cortex, especially the lateral PFC.
Bottom up processing involves more primitive structures such as the Brainstem
Basal ganglia (ventral striatum)
the limbic system (amygdala and hypothalamus)
The link between self control and volume of different areas (Kim et al 2020)
The thinner the PFC, the less self control
The larger the volume of the amygdala, the lower the self control, a person will be more likely to give in to impulses
Explain the balance model of self control propsoed by Lopez et al (2017)
The balance model proposes that self control is not due to either system (reward, control..) to be held inidividually responsible for failures in self control. Self control is predicted by the balance of acitivty in these different regions
Were the cognitive strategies effective in Kober et al (2010) to regulate participants cigarette cravings? What areas of the brain were activated when using these cognitive strategies
The cognitive strategies significantly reduced cravings and was assoicated with stronger activations of PFC and reduced activity in amygdala and ventral tegmental area
!!What feelings is the ventral striatum associated with? Which other brain regions does it recieve input from?
Its associated with reward, positive reinforcement/associations, addiction…
From amygdala (for threat and .. detection)
Hippocampus
ventral tegmental area (dopamine rich area of brain)
What is the nucleus accumbens?
It is found in the ventral striatum, related to impulses and self control
What are some likely traits of a person who has a stronger preference for smaller-soonger rewards?
They are more likley to be impulsive, prone to addiction, impatient…
What is the smaller-sooner vs larger-later paradigm?
paradigm that involves telling participants that they can get a little bit of something now, but if they wait longer they can get much more of that thing.
What did Aadakumar et al (2018) propose about the connectivtiy in the control and reward and the smaller-sooner .. paradigm?
They proposed that the connectivity in the cortical regions vs limbic regions is likely to influence whether a participant is more likely to choose the smaller-sooner or larger-later option. A greater connectivity between cortical regions (such as dlPFC, Anterior Cingulate Cortex) is more likely to choose larger-later than someone with good connectivity in the limbic system (amygdala, medial Orbitofrontal Cortex..)
What are two methods to carry out studies to create temporary lesions/inactivation of certain brain regions?
rTMS - repetitive Transcranial Magentic Stimulation
Magnetic waves interfere with brain decreasing the excitability of an area
tDCS - transcranial Direct Current Stimultion
Uses electrodes positioned over certain brain region and have current run through, changing the resting membrane potentials of the neurons
What are the dominant areas of the brain assoicated with self control?
PFC
ACC
AI
!!What was Tang et al (2013) findings on meditation and self control? Why was the resting potential of neurons relevant?
It was found that the resting potential/state of smokers (compared to non smokers) was higher than that of smokers, meaning they are triggered more easily into impulsive behaviour. There was less activity in self control areas such as PFC and ACC. After 2 weeks of meditation, there was an increased activation in resting state of ACC and PFC - the resting state of brain had been changed
What is Mischels marshmallow test and example of?
Of a delayed gratification test or smaller-sooner/larger-later test
Casey et al (2011) recruited the original participants of mischels marshmallow test 40 years later. What were the findings?
That the children who had not acted on impulse and chosen larger-later recruited, in adulthood, their PFC better/more often than those who had failed. Those who chose smaller-sooner relied more on subcortical areas such as the ventral striatum as adults
Previously it was thought that adolescents were impulsive, risk taking and in need of peer approval because of the underdeveloped PFC, why cant it just be due to underdeveloped PFC?
Because children also have an underdevloped PFC but do not show the same risk taking impulsive behaviour. The difference is probably that most key regions in the childs brain are underdeveloped whereas adolescents have some developed parts
What is the imbalance model of the brain and what does it try to explain in adolescents? Somerville & Casey (2010)
It proposes that the reason for which adolescents are prone to risk taking behaviour is because of the imbalance of the development of different brain regions. The PFC IS STILL UNDERDEVELOPED whereas the subcortical regions associated with reward, motivation and emotions develop earlier.
The result is a GREATER RELIANCE on SUBCORTICAL REGIONS than prefronal regions during adolescence.
What does presence of peers or emotional information trigger in the brain of an adolescent compared to adults? What is the importance?
Emotional information in experiment was perceived as positive social cues, explained by enhanced activity in the ventral striatum (reward circuit). Peer presence substantially increased the risk taking in adolescents and reliance on subcortical regions whereas adults was more generally PFC
What is the importance of the amygdala in our social brain?
It is the hub of our social brain, connected to many important cortical and subcortical regions. The amygdala can be considered to consist of three networks in a social context - the aversion, perception and affiliation networks
What is the perception network in the amygdala responsible for? What parts of the brain are responsible for these responses?
The perception network is responsible for detecting, decoding and interpreting social social signals and cues, such a sarcasm
VENTROLATERAL amygdala is key, and receives input from temporal cortex (associated with sensory input such as facial expressions) –> patients struggling to understand facial expressions were shown to have structural differences in amygdala, lateral OFC which are key for decoding social perception
What is the affiliation network of the amygdala? What parts of the brain are responsible for these responses?
The affiliation network is responsible for altruism and empathy, motivating prosocial or affiliative behaviours, such as comforting loved one
MEDIAL amygdala and vmPFC and subgenus ACC
Lower gray matter or thickness are associated with diminished empathy and interpersonal warmth
