Lecture 8 / Motivation

Motivation

An internal state that propels individuals to engage in goal-directed behavior.

Hunger in Blow Flies

Regulated by receptors in the legs that signal if a fly is standing on food and stretch signals from the stomach that indicate if it is not full.

Appetitive Behavior (The Seek)

A flexible, active searching phase driven by "wanting" and influenced by learning, such as checking the fridge.

Consummatory Behavior (The Do)

A fragile, stereotypical, and reflexive phase of engaging with a goal, such as the act of chewing and swallowing.

Drive Reduction Theory

Posits that biological needs (e.g., hunger, thirst) create unpleasant states of tension that compel individuals to act to return to homeostasis.

Incentive Motivation

Expecting certain outcomes based on certain decisions, and those expectations are what motivate the behavior.

Pavlovian Instrumental Transfer

A phenomenon where environmental cues associated with a reward alter the frequency or intensity of goal-directed behavior.

Dopamine and Motivation

A chemical system where performance in reward tasks declines if dopamine neurons die, but can be reversed by enhancing dopamine levels with substances like amphetamine.

The Reward System

A neural circuit centered on the ventral tegmental area (VTA) that involves the nucleus accumbens (NAcc) and the prefrontal cortex.

Incentive Salience Hypothesis

The theory that "wanting" (dopamine-driven urge) and "liking" (opioid-driven sensory pleasure) are two independent neurological processes.

Taste Reactivity

A method of studying pleasure by observing universal facial expressions (sweet vs. bitter) across species when they encounter rewards.

Amotivation

Diminished motivation for physical, cognitive, or emotional activity, often referred to in the context of neurological or psychiatric disorders.

Anhedonia

The inability to experience pleasure from activities that are usually enjoyable, which can include a loss of interest in previously rewarding activities.

Apathy

A state of indifference characterized by a lack of motivation and emotion, representing a decline from a person's previous functioning.

Avolition or Abulia

A condition where individuals are unable to generate action plans or options but can still perform the actions when verbally prompted.

Steps to Pursue a Goal

1. Generate options for achievement, 2. Make cost-benefit decisions and initiate behavior, 3. Reevaluate reward value based on enjoyment.

VTA (The Engine)

The part of the reward system that produces dopamine.

Ventral Striatum / NAcc (The Hype Man)

The part of the reward system that turns the dopamine spark into excitement and anticipation.

Prefrontal Cortex / PFC (The CEO)

The part of the reward system that receives excitement signals and decides whether to take action.

Addiction

A state of dependence characterized by a lack of control over consumption, use without achieving satiety, and an increased preoccupation with the substance or behavior.

Compulsion

Repetitive, ritualistic behavior that is no longer consciously controlled, driven by changes in the circulatory reward system.

PFC/OFC (The Brakes)

The front of the brain intended to stop harmful behaviors; these "brakes" weaken in addiction, making it physically difficult to stop.

D2R Downregulation

A process where repeated exposure to drugs or high-fat/sugar food reduces receptors in the striatum, impairing prefrontal regulation.

Behavioral Addictions

Dependencies on activities rather than substances, such as gambling, sexual addiction, and video game addiction.

Measuring Apathy (Tasks)

Researchers use pupil dilation and physical effort tasks (like grip force) to see how much reward is needed to motivate action.

Apathy Offer Likelihood

The likelihood of accepting a task increases with the reward amount (number of apples) and decreases with the effort required (height of the line).

Cocaine Compulsion Statistic

In experiments, about 80% of animals stop using cocaine when it is paired with an electric shock, while 20% continue despite the pain.

Ranking of Addictive Potential

Opiates are considered the most dangerous, followed closely by cocaine and barbiturates, then alcohol and nicotine