Lecture 18 - Motivation Flashcards Preview

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Flashcards in Lecture 18 - Motivation Deck (18):


construct used to explain variability and flexibility in behavior output attributable to external stimuli and internal states
-appetitively motivated behaviors: goal of attaining psoitive objects or envi consequences (food, water, sex)
-aversively motivated behaviors: prevent/terminate negative stimuli


Basal ganglia circuitry

input from cortical mantle --> striatum --> palladium --> thalamic
-indirect vs. direct pathway


Nucleus accumbens

ventral, medial, anterior aspect of basal ganglia
-part of the "limbic" CSPT circuit
-innervated by ascending dopamine pathways
-medium-spiny neurons receive NT signal and integrate multiple complex neurochemically specified inputs



modulates glutamate signals at spiny neurons


CPST loop

prefrontal cortex/amygdala/hippocampus --> nucleus accumbens --> ventral pallidum --> MD thalamus --> cortical motor-planning regions
-parallel loops from distict cortical areas
-palladial level of BG also outputs directly to brainstem
-specialized for motivationally relevant info


Ventral tegmental

strongest self-stimulation behavior
-input to hippocampus
-dopamine-rich = reward



dopamine regulated
-identify salient reinforcers and pursue them
-go after something
-important for learning about rewards:
> The 1st time experiencing new reward
> observing stimuli that reliably predicts award ***
> when previous reward is better than predicted
-dopamine firing early in training is direct response to reward
-dopamine firing later in training associated with stimulus that predicts reward



opioid regulated
-subjective emotional experience of pleasure upon interacting with reinforcer



progressively diminished phys response to drug with repeated exposure (right shift of dose-effect fx)
-opposite: sensitization



phys state induced by repeated exposure to drug where drug presence is necessary for normal function



subjective state of intense desire for particular goal



-loss of control over limiting intake
-habit persists despite negative consequences
-narrowing of other activities
-potential for relapse throughout life-span



homeostatic adaptation to drug = tolerance, and absence of drug = withdrawal
-expressed as physical symptoms or psychological symptoms
Opponent process theory
-rush/euphoria peak gets smaller over time due to adaptation, as does peak of withdrawal (gets worse)


Incentive-sensitization hypothesis

learning-based theory of addiction
-drug use leads to long-lasting sensitization of dopamine's ability to produce drug "wanting"


Reward-error prediction hypothesis

learning-based theory of addiction
-enhanced dopamine release during drug taking produces a condition in which ALL stimuli encountered during drug use are experienced as being "better than expected"


Impulsive behavior and addiction

2 relevant features:
1. tendency to consistently choose immediate reinforcement over delayed gratification, even when immediate reinforcement is smaller or less beneficial
2. impairment in ability to inhibit a course of action once initiated
-excessive "wanting" of drugs or drug-related stimuli, such that inhibitory control is overwhelmed
-impaired PFC function (nucleus accumbens gets input from PFC --> controls impulsivity, so if compromised lose inhibitory control so abnormal accumbens fx)


Compulsive behavior and addiction

repeat/prolong certain behavior strategy even in face of unsuccessful or adverse outcomes
-in addiction, individuals often report "wanting' the drug more even though they "like" it less. They also "want" the drug despite adverse outcomes
-shift from prefrontal-accumbens motor circuits to emphasis on dorsal striatal control
-dorsal striatum mediates compulsive "habits"


Addiction cycle

1. preoccupation/anticipation
--> (persistent desire, larger amounts taken than expected) 2. binge/intoxication
--> (tolerance, withdrawal, compromised social, occupational or recreational activities)
3. withdrawal/negative affect
--> preoccupation with obtaining, persistent physical/psych problems
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