Week 10 Lec 19 Flashcards
What are the primary unit of information processing?
Neurons
What are contact points between neurons
Synapses
How do you measure and manipulate electrical transmission?
Measure: Single unit recording
Manipulate: TMS, tDCS
How do you measure and manipulate chemical transmission?
Measure: Voltammetry
Manipulate: Drugs
How do you measure neurotransmitter levels?
PET neuroimaging
What parts of the brain have T receptors?
Amygdala, hypothalamus, VS
What facets of social behaviour is T implicated in?
Aggression, social dominance and status related behaviours
Where is T synthesized?
Adrenal glands and gonads
What did Apicella (2008) find when assessing if baseline T levels were associated with risk taking in an investment task?
They found that for every increase in one SD above the mean level of T, there was a 12% increase in investment
What were higher levels of endogenous T associated with?
Increased financial risk taking
What did Coates and Herbert (2008) find when investigating endogenous T in traders?
Traders earned more money on days they had elevated T in the morning
What have meta analyses on measuring endogenous T levels and risk taking?
Significant but small correlation between T levels and risk taking
What did Zethraeus find when assessing effect of T on economic behaviour?
Found that T and E did not influence altruism (DG), reciprocity (UG), trust and trustworthiness (TG) and risk attitudes
Study only used women and assessed over 4 week period
What did Stanton (2017) find when assessing T levels and consumer behaviour?
Found that driving a Porsche (reflecting higher status) led to increases in T when compared to driving an old car
What did Votinov (2020) find when assessing exogenous T levels and emotion regulation system?
Exogenous T levels disrupted resting state connectivity within fronto-subcortical and fronto-parietal circuits
Decreased connectively between right DLPFC and right amygdala
T modulates brain networks important for social emotional processing even in absence of specific task relevant to testosterone
What are neuromodulators?
Dopamine and serotonin
What did Imamura find after administering L-Dopa to patients?
L-dopa increased pathological gambling
What does blocking dopamine do?
Reduces risky choice
What did Long (2009) find when studying serotonin depletion?
Increased likelihood of choosing risky option when expected value was equivalent to safe choice (decreased safety premium)
What are time discounted values of delayed outcomes?
Preference for small immediate rewards over larger delayed rewards
Role in overeating, overspending and procrastination
What are therapeutic effects of amphetamines in ADHD?
Reduces impatient choice
Psychostimulants enhance dopaminergic neurotransmission (stimulates dopamine release and inhibits re-uptake)
What Pine (2010) find when combining temporal discounting and pharmacology?
Dopamine makes people more impatient (shifted preference towards short term rewards)
Increased dopamine increase discount rate (steeper discounting), leading to reduced SV for delayed rewards
How does dopamine affect brain regions with increasing delays to large rewards?
Decreases activity in the VS, Insula and lateral OFC
How does serotonin influence intertemporal choice?
Acute tryptophan depletion reduces serotonin, which makes people more impatient
What brain regions does serotonin modulate ITC?
Tryptophan/serotonin depletion enhances activity in VS during short term reward prediction
