L28 & 29 - Addictive behaviours Flashcards
What are the two highest causes of preventable deaths?
Alcohol and smoking
Of those regularly using a drug - % will become dependent (rate does not differ widely by type of drug)
10-15%
Stated below is how drug-related stimuli attain salience:
Drugs produce euphoria by activating _____ centres in the brain via release of __ in the _____ _______. The limbic system is closely tied to learning centres such as the _________, and repeatedly pairing drug-induced euphoria with drug-related stimuli creates an association
Pleasure/limbic, DA, nucleus accumbens, hippocampus
The magnitude of drug-related cue-induced activation of limbic and medial prefrontal regions predicts alcohol dependent individuals who subsequent relapse
The magnitude of drug-related cue-induced activation of limbic and medial prefrontal regions predicts alcohol dependent individuals who subsequent relapse
Damaging which cortical area will make smokes 100 times more likely to quit?
Insula cortex
*Not 100% fullproof so you wouldn’t want to get rid of insula cortex, it will affect other functions as well
If you looked at availability of D2 receptor in the mid brain - low or high availability linked to vulnerability to addiction and greater impulsivity to seek reward (drugs)?
Low - where else high availability has shown to be a protective factor (but this study was done in people in their 30s who still have a lot of time to become dependent on drugs)
What is the inverted U-shape curve hypothesis by Volkow
There is an optimal level of DA stimulation for the drug to be perceived as pleasant. Those with low D2 receptors will fill euphoria when drugs increase DA as in pushes it to the peak of the curve.
Those with high D2 receptors will fill unpleasant as the drug pushes them into the lower range of the curve
The level of DA metabolism depletion appears to worsen in?
Chronic Methamphetamine use
*Leads to greater impulsivity for reward
What gene influences the expression of DA D2 R density in the brain?
Taq1A allele - having 2 copies of the allele is associated with reduced density of D2 R in the striatum (midbrain), also predicts risk of drug dependence and may have resistance to drug treatment and learn following reward rather than from punishment
The DA hypothesis
People with low density of D2 R have increased desire to seek DA stimulation - direct (e.g. cocaine) or indirect (e.g. risky behaviour) and greater neural response to DA
Besides drug addiction, what other conditions are also characterized by low tonic levels of DA and impulsivity?
PD, Schiz, OCD, frontotemporal demention, Tourettte’s, Huntington’s
T/F - The role of DA in response inhibition is known
F- it is unclear
DA replacement therapy doesn’t work - may cause impulsive-compulsive behaviours instead THIS IS COUNTERINTUITIVE - This example shows that we know a little bit but it is still unclear
DA replacement therapy doesn’t work - may cause impulsive-compulsive behaviours instead THIS IS COUNTERINTUITIVE - This example shows that we know a little bit but it is still unclear
In delay discounting task - would heroine dependent individuals rather take the reward asap or wait for x amount of days?
Take it asap
Inhibitory control is when conscious internal goals take precedence over automatic processes
Inhibitory control is when conscious internal goals take precedence over automatic processes
What brain region detects the need for greater levels of control? And which brain region implements top-down control over performance?
ACC, DLPFC
in the stroop task, you are not stopping word reading but rather, amplifying the representation of the goal related task information - how is the ACC and DLPFC involved?
ACC detects the response conflict present in an incongruent word
DLPFC cognitive control system resolves this conflict through biasing attention to colour processing rather than word reading
If right inferior frontal gyrus is damaged - how is the stop-signal task time affected?
Decreased
Successful response inhibition requires a network of 3 regions - what are they?
Right Inferior frontal, Right parietal and Dorsal ACC regions
Dependent drug users and gamblers show significantly poorer performance on control tasks - this is due to lower activity in which cortical area?
dorsal ACC and DLPFC
Is prefrontal dysfunction present in drug-naïve children with a family history of drug dependence?
Yes
If you use drug-related words (evocative words) - they will be slower in responding to the colour of the item as they find it harder to control and ignore drug-related stimuli in the environment
If you use drug-related words (evocative words) - they will be slower in responding to the colour of the item as they find it harder to control and ignore drug-related stimuli in the environment
Does cognitive skills improve after abstinence from drugs?
Improvements only seen after 13 months - but only in motor abilities and info processing speed BUT no improvement in learning, memory and executive function
*We don’t look any further then after 13 months since the sample size tend to be a difficult bunch, moving around a lot
What drug increases attention in ADHD children?
Ritalin
