Problem 4 Flashcards
What is the pharmacologic working of MPH and AMP?
MPH results in less dopamine reuptake of the presynaptic neurons, AMP does the same but also result in more dopamine release. Both resulting in more dopamine in the synaptic cleft.
What could be alternative reasons for users experience effects of ‘smart pills’?
Placebo effect; the drug alters the students perception of work quality and amount; the drug enhances energy, wakefulness and motivation improving the work with an unchanged level of cognitive ability
Can you come up with additional explanations as to why smartpills have an effect?
Regression to the mean, undiagnosed ADHD, lower scoring baseline participants benefit more
What is the effects of AMP and MPH on learning?
The stimulants enhance consolidation in declarative learning, results where better after longer test periods
What is the effects of AMP and MPH on working memory?
Mixed results. Stimulants probably do enhance working memory for spme individuals (val/val)
What is the effects of AMP and MPH on cognitive control?
More null results than positive results. People who perform poorly on placebo, people with COMT val val gene, and people who are impulsive experienced cognitive enhancement
What is the effects of AMP and MPH on other executive functions?
Only two of eight studies found that stimulants enhanced cognitive performance so it is difficult to draw a conclusion
What is the pharmacological working of modafinil?
Stimulant drug that affects both online and offline processes; it directly inhibits central dopamine and norepinephrine uptake trabsporters, causing an elevation in the catecholamine levels, this enhances serotonin glutamate histamine and orexin and reduces GABA
What problems are there with using neuropsychological tests to examine cognition enhancing effects?
- simple tasks are too simple, whereas complex tasks are too difficult to standardize
- complex tasks cannot measure a single subcomponent of cognition
- there is a practice effect in a within-subject design
What are the differences between simple and complex tasks?
- simple tasks have a ceiling effect, complex tasks do not
- simple tasks can measure discrete subcomponents and compare them
- complex tasks can measure more integrated features of cognition
What did Battleday find on the effect of Modafinil in Simple tasks?
Simple tasks found benefits for executive functions (inhibitory control), learning (non-verbal short term memory)
What did Battleday find on the effevts on Complex tasks?
Complex tasks found an effect on attention, executive function and memory
What did Battleday find on the relationship between mood and modafinil?
Overall no changes in mood; some studies reported increasing anxiety and decreased contentedness
What recommendations does Battleday give for future task design?
- for use of healthy rather than clinical animal populations
- focus on one or more cognitive domains and their subcomponents
- integrate adaptive training and testing
- include testing on other un-trained cognitive domains
What recommendations does Battleday give for future trail design?
- test over multiple days
- include follow-up testing
- use a design that includes between and within subject
- include analysis of higher and lower baseline performers
- be required to report side effects
Ilieva et al suggestexplanations for mixed results for the enhancing properties of stimulants, what are they?
- moderation of enhancement by individual differences
- regression to the mean and baseline performance
- moderation by order of drug administration
Explain the goal of the MAS experiment:
Examining the actual cognitive rnhancing effects of MAS, and comparing it to the perceived cognitive effects
Explain the set up of the MAS experiment
first, there was a practice session where participants got acquainted with the tasks. After 2-4 days, the participants made baseline cognitive tests such as the SAT. After a week, the first pill was administered and again the cognitive tasks were made. After another week, the second pill was administered and again the cognitive tasks were made.
Did they use control groups in the MAS experiment?
- The placebo group is the control group; it’s a 2x2x2 design, where the first factor is drugs vs. placebo; it is a placebo-controlled study!
- Counterbalancing in the order of the drug administration (between-subjects);
- The study was double-blind
Explain the results of the MAS expermient?
- The was no enhancinf effect on cognitive performance
- below-median performers had more enhancement
- Participants perceived more enhancement subjectively
What shortcomings of their study do Ilieva et al. mention?
Did not vary drug doses; only used Adderall and no other enhancers; did not measure bioavailability; the participants were not representative of the general population (all white males); all participants had a health criteria
Explain the set-up of the Wadha et al. experiment
Rats were used and given caffeine and modafinil, during a phase of 48 sleep deprivation. The sleep deprivation was induced by shaking the cage when the rats fell asleep. The effects of sleep deprivation on short term memory performance was evaluated by a novel recognition tasks. After, the rats were euthanized and the brain tissue was collected and examined.
Did Wdha et al. use control groups?
yes. They had seven conditions, where sleep deprivation, normal sleep, and aparatus control were compared. And Modafinil, caffeine, and saline were compared.
Explain the results of Wadha et al. at the behavioral level
Sleep deprived rats scored more poorly on the NORT test; however, caffeine and modafinil treatment improved the memory performance on NORT for the sleep deprived rats, compared to sleep deprived rats that were treated with saline. Rats that were not sleep deprived showed no effect whether they were treated with caffeine, modafinil or saline
