1 / 11

LECTURE 23: EMOTIONS, MOTIVATION, AND DRUGS OF ABUSE

LECTURE 23: EMOTIONS, MOTIVATION, AND DRUGS OF ABUSE. REQUIRED READING: Kandel text, Chapters 50, 51. Emotion and Feeling are two interconnected states. Emotion is a group of physiological and motor responses to a set of stimuli.

chelsea-roth
Download Presentation

LECTURE 23: EMOTIONS, MOTIVATION, AND DRUGS OF ABUSE

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. LECTURE 23: EMOTIONS, MOTIVATION, AND DRUGS OF ABUSE REQUIRED READING: Kandel text, Chapters 50, 51 Emotion and Feeling are two interconnected states. Emotion is a group of physiological and motor responses to a set of stimuli. These emotional responses communicate our state to others, prepare us or drive us for consequent action, and have powerful effects on our unconscious (implicit) memory of the stimulus events. Feeling represent the conscious (explicit) awareness of our emotional state. EXAMPLES: The taste of a great dessert can elicit the emotion of enjoyment and satisfaction and the feeling of having something delicious Upon hearing a joke, one may experience the emotion of laughter and the feeling of a funny experience EMOTIONS EXERT POWERFUL INFLUENCES ON MOTIVATIONAL BEHAVIOR

  2. EMOTIONAL EXPERIENCES CAN BE STEREOTYPICAL OR SUBJECTIVE Hearing an unanticipated loud explosion triggers a startle emotion characterized by heightened awareness, shivering or freezing, elevated pulse and blood pressure, and a specific facial expression, while triggering the feeling of fear Seeing David Ortiz of the Boston Red Sox hit a home run against the New York Yankees can trigger exhaltation, sadness, or nothing depending upon one’s interest in baseball and whether one is a Red Sox or Yankees fan Why?: Just as conscious cortical activity can shape our reflexive responses to stimuli, it can also shape our automatic emotional responses to certain stimuli Conscious decisions can shape value (ethical) judgments which inform our emotional responses

  3. THE LIMBIC SYSTEM CONTROLS GENERATION OF EMOTIONAL STATES

  4. THE AMYGDALA IS CRITICAL FOR EMOTIONAL RESPONSES, PARTICULARLY TO NEGATIVE EMOTIONS

  5. LEARNED EMOTIONAL RESPONSES ARE PROCESSED IN THE AMYGDALA

  6. AMYGDALA AND HIPPOCAMPUS ARE SEPARATELY NEEDED FOR THE FEARFUL AND COGNITIVE COMPONENTS OF PAST EXPERIENCE Individuals with brain lesions were shown different colored slides, and some slide colors were followed by a loud startling noise LESION CONSCIOUS MEMORY LEARNED FEAR OF COLORS OF COLORS NONE YES YES AMYGDALA YES NO HIPPOCAMPUS NO YES BOTH NO NO

  7. DEAZOPENE (VALIUM) INHIBITS FEAR AND ANXIETY Valium is a widely used medication used to reduce anxiety and fear, often prescribed prior to surgeries without general anesthesia Valium interacts with GABA ionotropic receptors, and enhances GABA-induced chloride conductance. At optimal dosages, valium inhibits firing of neurons in fear and anxiety circuits Valium is often used, often addictively, as a means to relieve “life” stress

  8. MOTIVATIONAL BEHAVIORS ARE OFTEN DIRECTED TOWARDS MAINTENANCE OF PHYSIOLOGICAL HOMEOSTASIS The hypothalamus plays a pivotal role in homeostatic motivations, acting as physiological sensor and coordinating autonomic and motivational responses Examples: Thermal regulation: Certain hypothalamic neurons fire at different rates at different temperatures. Deviation from set point (37oC in humans) triggers other regions of hypothalamus initiate autonomic functions and behavioral drives Appetite: Hunger level is driven in part by hypothalamic control. Certain hypothalamic neurons have receptors for a hormone, leptin, which is produced by fat tissue. Leptin suppresses apetite.

  9. SOME MOTIVATIONS ARE NOT DRIVEN BY DIRECT PHYSIOLOGICAL NEEDS, BUT BY PLEASURABLE EMOTIONS AND ANTICIPATION OF PLEASURE We (and rats) tend to eat more calories of flavorful food than bland diet Sexual behavior is drive towards pleasure fulfillment Stimuli that are pleasurable are believed to signal “pleasure” by activating certain midbrain dopaminergic neurons in the ventral tegmental area (VTA) that project to the nucleus accumbens (NA) region of the forebrain Rats can be implanted with electrodes into the VTA, with stimulation triggered by the animals pressing a lever. Such animals learn to frequently self-”reward” by pressing the lever

  10. MANY DRUGS OF ABUSE ACT BY PROMOTING THE DOPAMINERGIC PLEASURE CIRCUIT Cocaine and amphetamines act by blocking dopamine reuptake transporters, resulting in prolonged dopaminergic signaling. These drugs cause sensory-independent sensation of pleasure and also enhance pleasure associated with certain stimuli Nicotine mediates excess release of VTA dopamine by stimulating presynaptic cholinergic receptors on VTA axons Mu opiates (e.g., morphine) act by inhibiting GABAergic neurons that project to VTA dopaminergic neurons

  11. DRUG CRAVING CAN BE TRIGGERED BY SENSORY CUES ASSOCIATED WITH DRUG USE: A FORM OF CONDITIONED STIMULUS Drug exposure follows a sequence of behavioral and sensory cues that act as conditioning stimuli to the drug unconditional stimulus Consequence is conditioned response, whereby the cues alone trigger anticipation of drug “reward”

More Related