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Motivation
behavior that seems purposeful and goal directed
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Drive
Hypothetical state of arousal that motivates an organism to engage in particular behavior
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"Flush" model
- Once a behavior is started it will continue until all the energy in its reservoir is gone.
- Separate stores of energy for different behaviors
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Reinforcer
- operant conditioning any event that strengthens the behavior that it follows
- B.F. Skinner
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Learned Taste Aversion
- Aquired association between a specific taste or odor and illness
- leads to an aversion to foods having that taste or odor
- Ex. dead sheep + poison= sad cyote
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Prepardness
- Predisposition to respond to certain stimuli differently than other stimuli
- brain is prewired to make certain types of associations but not others
- Ex. two mice in one cage -> one recieves shock, thinks it's from the other mouse -> ATTACK!!!!
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What are the critical structures of motivated behavior
- Hypothalamus and associated pituitary gland
- Limbic system
- Frontal lobes
- Both limbic system and frontal lobes project to the hypothalamus
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Homeostatic Mechanism
Process that maintains critical body functions within a narrow, fixed range
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Regulatory Behavior
- Behavior motivated to meet the survival needs of the animal
- controlled by homeostatic mechanisms, which INVOLVE THE HYPOTHALAMUS
- Ex. internal body temperature , eating, drinking, salt consumption, waste elimination
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Nonregulatory Behavior
- Behavior unnecessary to meet the basic survival needs
- most involve the frontal lobes more than the hypothalamus (frontal lobes > hypothalamus)
- strongly influenced by the external stimuli.
- Ex. parental behavior, aggression, food preferance, curiosity, reading, SEXY TIME! BOOM BOOM! SKEET SKEET!
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Pituitary Gland
- Endocrine gland attached to the bottom of the hypothalamus
- secretions control the activities of many other endocrine glands
- known to be associated with biological rhythms
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Factors involved in controlling hypothalamic hormone-related activity
- Feedback loops
- Neural regulation
- Experiential responses
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Feedback Loops
Control the amount of hormone that is released
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Neural Regulation
Other brain regions- limbic system and frontal lobes- influence hormone release
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Experiential Responses
Experience can alter the structure and function of hypothalamic neurons
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Electrical stimulation of different nuclei in the hypothalamus will produce goal-directed behaviors, such as:
- Eating and drinking
- Digging
- Displaying fear
- Predatory or attack behavior
- Reproductive behavior
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Amygdala
- Almond-shaped collection of nuclei located within the limbic system
- receives input from all sensory systems
- sends projections primarily to the hypothalamus and brainstem
- influences autonomic and hormonal responses via connections with the hypothalamus
- influences conscious awareness of the consequenses of events and objects via connections with the prefrontal cortex
- involved in species-specific behaviors and emotion
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Klüver-Bucy syndrome
- first shown in rhesus monkeys with large BILATERAL LESIONS OF THE AMYGDALA
- affects social behavior
- caused monkeys to:
- eat anything
- placidity
- lack of fear/aggression
- hypersexuality- FUCK ANY OBJECT THAT TICKLES YOUR FANCY ie- chair, horse, pig, pencil sharpener.
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Three main regions of frontal lobe
- motor cortex
- premotor cortex
- prefrontal cortex
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Motor cortex
Controls fine movements
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Premotor Cortex
Selection of appropriate movement sequences
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Prefrontal Cortex
Involved in specifying the goals toward which movemet should be made
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Three components of emotion
- Autonomic Response- increased heart rate, hypothalamus and associated structures
- Subjective Feelings- fear, amygdala and parts of frontal lobes
- Cognitions- thoughts about the experience, cerebral cortex
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Emotion
- Arouse the autonomic nercous system
- Each situation evokes its own mixture of sympathetic and parasympathetic arousal
- Measurement of evoked responses indicate the brain is specialized to attend strongly to facial expressions
- Not localized in specific parts of the cortex
- single emotion increases activity in various parts of the brain
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James-Lange View of Emotion
- Physiological changes produced by the autonomic nervous system come first
- Brain interprets these changes as an emotion
- EVIDENCE: intensity of emotions in individuals with spinal cord damage depends upon how far up on the spinal cord that the damage is located
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Somatic Marker Hypothesis
- Posits that "marker" signals arising from emotions and feelings act to guide behavior and decision making
- ususally unconscious process
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