Applied Cognitive Psychology food and drugs Flashcards
Detour: (In)Activation of Neurotransmitters
- Blocking release of Neurotransmitter
- Botulinium toxin (ACh) - > muscle paralysis
- Clozapine in Schizophrenia ( ↓ DA) - Reuptake by axon terminals or glial cells for reuse
- Cocaine and Speed delay reuptake of Norepinephrine (↑ pleasure)
- Anti-depressants (Prozac) block reuptake of Serotonin
- Lithium speeds reuptake ( ↓ DA) - Deactivated by enzymes
- COMT –gene encodes an enzyme that modulates DA in the PFC
- Nerve gas (VX) destroys AChE - Diffusion via blood
Dopamine
- “Pleasure” substance
Dopamine Associated with:
- Reward (ice-cream, promotions, ‘schadenfreude’, love :)
- Goal Proximity (to-do lists, video games)
- Motivation (trouble in Parkinson’s)
Dopamine and ADHD=
High Dopamine Transporter Density
- Impulsive, Increased cravings
- Reduced inhibition
Dopamine and Schizophrenia
: Overactive Dopamine
- DA-antagonists (blockers) reduce Hallucinations
Executive Functions
- Working memory = Updating/Monitoring
- Shifting= Switching/Shifting
- Inhibition
Wisconsin Card Sorting Task
- Working memory = Updating/Monitoring
The Wisconsin Card Sorting Task (WCST) is a neuropsychological test used to assess cognitive abilities, particularly abstract reasoning, cognitive flexibility, and executive functions. Participants are asked to sort cards based on different criteria, such as color, shape, or number, with the criteria changing throughout the test. The ability to adapt to these changes and learn new rules is evaluated. The WCST is valuable in diagnosing various neurological conditions and tracking changes in cognitive flexibility over time.
n-Back task
- Working memory = Updating/Monitoring
The n-Back task is a cognitive test used in psychology and neuroscience to assess working memory and attention. During the task, participants are presented with a series of stimuli, such as letters, numbers, or shapes, one at a time. They are then asked to indicate whether the current stimulus matches the one presented “n” steps earlier in the sequence. The value of “n” can vary, typically ranging from 1 to 3, with higher values indicating greater working memory demand. The task requires individuals to continuously update and maintain information in their working memory while simultaneously processing new stimuli, providing insight into their ability to sustain attention and manipulate information in real-time.
Executive Function: 1. Working memory = Updating/Monitoring Updating/Monitoring
- Primarily -> Working Memory
- Encode relevant incoming information
- Update/revise existing representations
- Manipulate representations
- Monitor for changes
Task Switching Paradigm (Alternate Runs)
- Shifting= Switching/Shifting
Executive Function: Switching/Shifting
- Engagement of a new/relevant task
- Disengagement from an old/irrelevant task
- Suppress proactive interference
Stop Signal Task
- Inhibition
The Stop Signal Task is a cognitive task designed to measure response inhibition, a component of executive function. In this task, participants are typically presented with a series of stimuli and instructed to respond to one type of stimulus as quickly as possible. However, occasionally, a “stop signal” is presented shortly after the initial stimulus, indicating that the participant should inhibit their planned response.
The main measure of interest in the Stop Signal Task is the “stop signal reaction time” (SSRT), which is the average time it takes for a participant to inhibit a response after the stop signal is presented. A longer SSRT indicates poorer response inhibition.
The Stop Signal Task is used in psychological research to assess inhibitory control and impulse control, and it has applications in studying disorders such as attention-deficit/hyperactivity disorder (ADHD), substance abuse disorders, and impulse control disorders.
Executive Function: Inhibition
- Suppress irrelevant but dominant actions
- Dominant actions can be:
Learned habits
Personality traits or tendencies
Practiced actions or overlearned skills
Cognitive Control Dilemma
Individual differences!
Dopamine & Cognitive Control
Flexibility vs Stability
Nigrostriatal Pathway:
The Nigrostriatal Pathway, primarily associated with motor control, indirectly influences cognitive functions such as working memory in the prefrontal cortex. While it doesn’t directly project to the prefrontal cortex, its connections with other brain regions, like the basal ganglia, suggest a role in cognitive processes. Dopamine, the neurotransmitter in this pathway, may modulate prefrontal cortical activity, impacting functions like working memory.
Nigrostriatal Pathway provides a signal to update
or maintain WM in the PFC
Tuberoinfundibular Pathway:
This pathway regulates the secretion of hormones from the pituitary gland, specifically the regulation of prolactin.
It connects the hypothalamus to the pituitary gland.
Dopamine released from neurons in the hypothalamus inhibits the release of prolactin from the anterior pituitary. This inhibition helps regulate the levels of prolactin in the bloodstream.
Dysfunction in this pathway can lead to hyperprolactinemia, a condition characterized by elevated levels of prolactin in the blood, which can result in symptoms such as menstrual irregularities, infertility, and lactation outside of pregnancy.
Mesolimbic Pathway:
This pathway is associated with the brain’s reward system and plays a role in motivation, reinforcement, and addiction.
It originates in the ventral tegmental area (VTA), located in the midbrain, and projects to various areas of the limbic system, including the nucleus accumbens, amygdala, and prefrontal cortex.
Dopamine released from neurons in the VTA is involved in mediating the pleasurable effects of rewarding stimuli, such as food, sex, and drugs. It reinforces behaviors that lead to the activation of this pathway.
Dysfunction in the mesolimbic pathway has been implicated in addiction and various psychiatric disorders, including depression and schizophrenia. Dysfunction can lead to abnormalities in reward processing, motivation, and emotional regulation.
High Prefrontal DA ->
Cognitive Stability
(goal maintenance, focusing, suppressing distraction, but inflexible/insensitive)
Low Prefrontal DA->
Cognitive Flexibility
(flexibility - inhibition and switching), but prone to distraction, interference)
U-shaped curve & Dopamine Level
- Both high and low levels of DA are associated with
low cognitive performance. - We all inherently tend to optimise our baseline DA
levels by using CNS stimulants or depressants or
both, sometimes together
schizophenia overdosing
Effects of a drug can depend on many factors:
- Type and difficulty of task
- Genetics predisposition
- Type of drug (stimulant/depressant)
- Dosage, Consumption history
- Age, Gender, Disease, Infection, Immunity..
Parkison and adhd
Detour: COMT-Gene Polymorphism
- Enzymes in the COMT gene inactivate released dopamine,
thereby regulating its flux in the PFC. - COMT gene has 2 flavors or ‘alleles’: Val-Val, Met-Met
Valine amino-acid ->
Fast DA loss -> Low PFC DA
- “Warriors”
- Resilient to stress, Relax quicker
FLEXIBILITY
- Val-allele -> ______ Dopamine in the PFC -> __________ in Stability, but _______ at Flexibility.
low, low, High
Methionine ->
Slow DA loss -> High PFC DA
- More DA is not necessarily a good thing
- “Worriers”
- Neurotic, less resilient to stress
- Higher IQ, do well at school, creative
STABILITY
Met-allele -> ______ Dopamine in the PFC -> Good at _________________, but bad at _________
High, Goal maintance , Inhibition
Nigrostriatal Pathway PROMOTES:
Low Prefrontal DA -> Cognitive Flexibility
Mesolimbic Pathway PROMOTES:
High Prefrontal DA -> Cognitive Stability
Stability vs. Flexibility in COMT genotypes
KIJKTABEL
Delaying the __________ mechanism of ___________ neurotransmitter is central to prolonging the
‘pleasure’ attained from drugs like Cocaine.
Reuptake , dopamine
AMP & Wisconsin Card Sorting = with dopamine Task Val-Val vs. Met-Met : Predictions?
KIJKTABEL
WCST and AMP
Val-carriers (Low PFC DA) are worse in sustained attention task as compared to Met-carriers, but improve with AMP. Met-carriers show decline with AMP.
dus val gaat beter met amphetamine aantal errors neemt af
en met gaat minder goed met amphetamine aantal errors neemt toe
Placebo/Baseline WCST en AMP=
Val + PBO < Met + PBO
Higher errors in Val
N-Back task and AMP
KIJK NOTES
Tyrosine: Alternative to Dopamine Drugs
- Precursor of Dopamine (and NE), naturally produced in body
- Source: Apples, soy, chicken, fish, milk, spinach etc.
- 1 hr after intake, DA levels go up. Half life = 2 hrs.
- Can reverse mental decline and improve cognition in shortterm
- Low TyrH expression in Parkinson’s
- Very difficult to overdose on TYR due to limited TyrH!
- Safe to use as compared to performance enhancing
supplements like Ritalin.
Tyrosine formula
Tyrosine + tyrosine hydroxyfase toe* is limited) ->
L-DOPA + (DOPADECARBOXYFASE) ->
DOPAMINE + DOPAMINE B-HYDROXYLASE ->
= NOREPINEPRHINE = noradrenaline
Tyrosine: Reversing DA depletion Why is there no effect in 1-Back task?
Serotonin
“Happy” neurotransmitter
Serotonin is associated with:
- Sleep, Mood
- Aggression
- OCD (reduced information processing)
- Low – Depression, Autism, OCD
- High – Serotonin Syndrome
Decreasing serotonin leads to:
- Less affiliative behavior (social/emotional bonding)
- Increased aggression
- Stronger response to unfairness
- Bias towards negative stimuli
Tryptophan Alternative to
Serotonin Drugs
Tryptophan=
- Precursor to Serotonin (and melatonin)
- Not produced naturally in the body
- Source: Salmon, Poultry, Eggs, Spinach, Nuts etc.
- Half life = 2hours.
- Used for treating depression, anxiety and as a sleep aid.
- Increases recall of positive material
- Decreases recognition of negative faces
Tryptophan formula
Tryptophan+ Tryptophan hydroxylase ->
5-HydroxyTryptophan (5HPT)
+ AROMATIC L-AMINOACID DECARBOXYLASE
=5 HYDROXYTRYPTAMI (5 HT: SEROTINE)
Tryptophan induces a
+ve emotional bias
Those who received the tryptophan supplement might show a tendency to rate positive stimuli more positively or recall more positive stimuli compared to those who received the placebo. This shift towards a positive emotional bias could suggest that tryptophan supplementation has influenced their emotional processing.
On AMP, Val-individuals show a/an ___________ in performance on ________________ type of tasks
- At _______ task load, Met-carriers on AMP perform _________ than Val-carriers
Increase, substained attention, high, worse
Long-term and Recreational drug users are __________ than non-users in time-critical situations like
_________. Lifetime exposure to cocaine is ________ correlated with the extent of this deficit.
worse, driving, positively
In ____________ situations, Tyrosine supplements can ___________ DA depletion.
stressfull, reverse
Reduced serotonin activity leads to less ____________ and more ____________ behavior.
affiliate, aggresive
____________ is a supplement that is useful in reducing __________ and promoting sleep
Tryptophan, anxiety
Recreational and long-term users of Cocaine show
inhibition deficits – Effect of Dosage
The effect of DA on cognition follows an inverted U-shaped curve and depends on:
- Baseline DA levels, Genetic predispositions
- Task (+Difficulty), Stress
- Dosage & Consumption history
- Age, Gender, Disease, Infection, Immunity..
Tyrosine enhances _________ control and cognitive_______, especially beneficial in______ situations
inhibitory, flexibility, stressful
Unlike Ritalin, Tyrosine cannot be overdosed due to ________
limited TyrH availability
________ are crucial in understanding the effect of psychoactive drugs.
Individual differences
