Chapter 12 Flashcards
Emotions
Cognitive interpretations of subjective experiences
Innate releasing mechanism
Hypothetical
Detects specific sensory stimuli, directs an organism to take a particular action
Aids survival
Innate but modified by experience
Evolutionary psychology
Assume behaviour occurs because natural selection favoured the neural circuits that produce it
Neural circuits
Brain circuits for reward that can modulate to increase or decrease activity
Skinner- environmental influences
Certain events function as reinforcers
When a reinforcer follows a particular action similar actions are more likely to occur
Learned tase aversion
Acquired association between a specific tase or odour and an illness leading to an aversion
associative learning
Preparedness
Predisposition to respond to certain stimuli differently from other stimuli
prewired to make certain associations but not others
Olfactory receptors
Scent interacts with chemical receptors
Receptors constantly replaced
Each receptor ends in cilia in a mucous layer
Olfactory epithelium
Receptor surface for olfaction in the nasal cavity
receptors and support cells
Olfactory bulb
gets information from receptor cells, synapses with mitral cells which connect to forebrain areas
Thalamic connection in olfaction
Most targets have no connection through the thalamus
There is a thalamic connection to the orbitofrontal cortex
Oribitofrontal cortex
Prefrontal area behind the eye sockets
Emotional and social behaviours including eating
Pheromones
Biochemicals released by one animal that act as chemosignals
Affect the behaviour of another animal of the same species
Detected by vemernasal organ
Vemeronasal organ
Detects pheromones
Sends axons to accessory olfactory bulb that connects with the amygdala and hypothalamus- role in reproductive and social behaviour
Gustatory receptors
Tastebuds on an under the tongue, roof of mouth, sides of mouth, back of mouth. nasopharynx
Sweet, sour, salty, bitter
taste buds
Groups of gustatory receptors
Each contains several (or all) receptor types
Solitary tract (gustation)
Cranial nerves 7. 9. 10- main gustatory nerve
Splits in the brainstem
1st gustatory route
Projections to somatosensory cortex: tactile info and texture
Primary gustatory cortex: taste
Orbital frontal cortex: perception of flavour, affected by ambience
2nd gustatory route
Goes to the hypothalamus and amygdala
Regulatory behaviours
Motivated by an organisms survival
Controlled by homeostatic mechanism
Homeostatic mechanisms
Maintains critical body functions within a narrow range
Nonregulatory behaviours
Not required to meet basic survival needs
Not controlled my homeostatic mechanism
Hypothalamic circuit
Hypothalamus acts on the endocrine system and the ANS to regulate the internal environment
Influences behaviours selected by the rest of the brain
Medial forebrain bundle
Connects the brainstem with the limbic system
Forms activating projections that run from the brainstem to the basal ganglia and frontal cortex
Hypothalamic tract peptides
Neurones in hypothalamus make peptides that are transported down their axon to the posterior pituitary
Posterior pituitary
Receives peptides from hypothalamus
Sends APs to terminals to release stored peptides
Peptides enter the blood stream
Anterior pituitary
Synthesizes hormones
Hypothalamus controls the release by producing releasing hromrones
Feedback loops
Homeostatic control, regulates the initiation of neural activity or hormonal release
Hypothalamus and experimental responses
Neurons in the hypothalamus undergo changes in response to experience
changes can affect hormones
Hypothalamus and generating behaviour
Central to goal-directed behaviour
When the hypothalamus is stimulated in animals they engage in complex behaviours
3 parts controlling eating
Cognitive factors: thinking about food, environmental cues
Hypothalamus
Digestive system
Digestive system
Controlled by ENS
As door travels through the tract, nutrients are extracted
Body has detector cells to track the level of each nutrient in the blood stream
Glucose
Primary fuel, only energy source for the brain
What happens when blood sugar (glucose) levels are low
Detector cells tell the liver to convert glycogen into glucose for release
Feedback mechanisms of the digestive system
When food reaches the intestines it interacts with ENS receptors to trigger release of peptide hormones
Hormones act as satiation or satiety signals
Hypothalamus and eatin
Eating influenced by hormones
Lateral hypothalamus and eating
Damage causes aphagia: stops eating
Stimulation elicits eating
Ventromedial hypothalamus and eating
Damage causes hyperphasia: overeating
Stimulation inhibits eating
2 major classes of neurons in arcuate nucleus (eating)
one initiates eating, one reduces eating Changes in hormone levels reflecting glucose and lipid levels stimulate either class of neurons
Cognitive control of eating
Pleasure or absence of pleasure
External sensations and learned associations
Damage to amygdala and eating
Damage alters food preferences and abolishes taste aversion learning
Damage to orbitofrontal cortex and eating
decreases eating due to diminished sensory responses
Osmotic thirst
Results from a high concentration of dissolved chemicals in body fluids
Receptors in hypothalamus detect solute concentration and send message to stimulate us to drink and reduce water excretion in kidneys
Water intoxication
Drinking more water than the kidneys can handle
body tissues swell with fluid and drowns the cells
Electrolyte imbalance
Hypovolemic thirst
When the total volume of body fluid declines
Encourages us to choose something other than water so the solute concentration isn’t diluted
When fluid volume drops kidneys send hormone signal, stimulates hypothalamus, stimulates drinking
2 general effects of gonadal hormones
Organizing- gonadal hormones organize the brain during development
Activate sex-specific behaviours in adulthood
Organizing effects of gonadal hormones
During fetal development, testes produce androgens which alter structures
cells in the brain produce aromatase which converts testosterone into estradiol which masculinizes the male brain
Activating effects of gonadal hormones
Ovarian hormones can change structures of dendrites and synapses
Testosterone activates sexual behaviour
Hypothalamus and sexual behaviour
Controls copulatory behaviour in males and females
Ventromedial hypothalamus and sexual behaviour
Controls female mating posture
Medial preoptic area and sexual behaviour
Controls copulation in males
Does not control motivation
Amygdala and sexual behaviour
Controls motivation
Sexual determination
Determined during early development, genetic and epigenetic factors
Differences in the hypothalamus
Cognitive influences of sexual behaviour
The cortex is not essential for motivation and copulation
Involved in imagining sexual activity and thinking about and planning sexual activity
3 forms of emotional experience
Autonomic responses
Strong subjective feelings
Thoughts or plans related to the experience
Constructivist theory of emotion (James-Lange theory)
The brain interprets physiological changes as emotions
Produces a cognitive response to autonomic information
Appraisal theory of emotion
Emotions are processes rather than states
Activity of biological subsystems and extensive neural networks
4 biological subsystems of the appraisal theory of emotion
Appraisal component: evaluation
Semantic component: physiological
Behavioural component
Feeling component: subjective
General neuropsychological theory of emotion
Emotional control is lateralized
Left hemisphere interprets feelings
Right hemisphere has a role in producing strong emotions and is more automatic
Limbic circuit
How emotion reaches consciousness
The hippocampus, amygdala, and prefrontal cortex all connect with the hypothalamus
3 subdivisions of the amygdala
Corticomedial area
Basolateral area
Central area
Amygdala
Receives inputs from all sensory systems
Many neurons are multimodal
Sends connections primarily to the hypothalamus and brain stem
Kluver-Bury syndrome
Removal of amygdala of monkeys
Principal symptoms include: loss of fear, indiscriminate dietary behaviour, increase in autoerotic activity with inappropriate objects, attend to every visual stimulus, came all objects by mouth
2 components of awareness of danger and safety
Innate component: automatic processing of species-relevant sensory information
Learned component: avoidance of specific things the organism associates with danger (involvement of amygdala)
Role of prefrontal cortex
Selects behaviours appropriate to the particular time and place
Receives highly processed info from all sensory areas
Specifying goals
inferior prefrontal region
Sends axons to amygdala and hypothalamus
Route for influencing ANS and ENS and internal processes of emotions
Dorsolateral prefrontal region
Larger role in cognitive behaviours not emotional
Ventromedial prefrontal cortex
Role in decision making
Major depression
Prolonged feelings of worthlessness and guilt, disruptions of normal eating habits, sleep disturbances, slowing of behaviour
Genetic component
Role of epigenetic changes: early life stress
3 main components of reward
Learning about rewards and their availability cues
Motivation for rewards and associated cues
Affective responses to pleasure of rewards
Intracranial self-stimulation
Rats press a bar to administer stimulation to specific sites of their brain
Activating system underlying rewards
2 independent processes of reward
Wanting and liking
Wanting
Generated by a large distributed brain system
Dopamine projections
Liking
Generated by a smaller set of hedonic areas within limbic circuitry
Hedonic hotspots
Opioids and endocannibanoids
Hedonic gloss
Networks of hedonic hotspots (pleasure) and cold spots (displeasure)
