Lecture 18 - Motivation Flashcards Preview

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Flashcards in Lecture 18 - Motivation Deck (18):
1

Motivation

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

2

Basal ganglia circuitry

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

3

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

4

Dopamine

modulates glutamate signals at spiny neurons

5

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

6

Ventral tegmental

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

7

"wanting"

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

8

"liking"

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

9

Tolerance

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

10

Dependence

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

11

Craving

subjective state of intense desire for particular goal

12

Addiction

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

13

Withdrawal

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)

14

Incentive-sensitization hypothesis

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

15

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"

16

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)

17

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"

18

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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