Chapter 12 - Emotional and Motivated Behavior Flashcards
innate releasing mechanisms (IRMs)
mechanisms that detect specific stimuli (e.g. seeing a prey) and direct an organism to take a particular action (e.g. stalking the prey)
preparedness
the nervous system has a predisposition to respond to certain stimuli differently from other stimuli
olfaction (smell)
used to discriminate between something safe/familiar and something unsafe/unfamiliar
- about 400 types of olfactory receptors embedded in the olfactory epithelium in the nasal cavity
olfactory bulb
where olfactory receptors project to
- connected primarily to the pyriform cortex and the amygdala (primary pathway), and via the thalamus to the orbitofrontal cortex (secondary pathway)
pheromones
biochemical fragrances released by an animal that acts as a chemical signal and influences the physiology or behavior of another animal
gustation (taste)
important for emotional and motivated behavior
- five types of taste receptors: sweet, salty, sour, bitter, and umami (savory)
- all receptors distributed over the tongue, soft-palate, roof of the mouth, sides of the mouth, and back of the mouth
gustatory pathways to the brain
- the first goes through the thalamus and reaches S1 and the primary gustatory cortex
- the second goes directly to the hypothalamus and amygdala
regulatory behavior
behavior motivated to meet the survival needs of the animal
- necessary for survival such as eating behavior, drinking behavior, and temperature management
- regulated by internal stimuli via the hypothalamus
- necessary for a single individual and is caused by the homeostatic mechanism
non-regulatory behavior
not necessary for the survival of the individual but may be necessary for the survival of the species
- e.g. sexual behaivor, parental behavior, and curiosity
- strongly influenced by external stimuli via the hypothalamus, limbic system, and the prefrontal cortex
most important neural structures in emotional and motivated behavior
hypothalamus, pituitary gland, limbic system, and frontal lobes
homeostasis
keeping the internal state of the body constant within precisely defined limits, a so-called set point
- by regulating vital body functions
- hypothalamus is important for homeostatic mechanisms
hypothalamus
involved in emotions, reproduction, the autonomic nervous system, and the hormonal (endocrine) system
- one primary function is to control the pituitary gland
pituitary gland
is an endocrine gland on the underside of the hypothalamus
- located just behind the optic chiasm
- consists of 2 systems: posterior and anterior pituitary
posterior pituitary
made of neural tissue
- receives hormones from the hypothalamus through axons, and releases hormones into the bloodstream through capillaries
anterior pituitary
made of glandular tissue
- receives releasing hormones from the hypothalamus through capillaries
- releasing hormones can either stimulate or inhibit the release of anterior pituitary hormones into the bloodstream
- synthesizes its own horomones (growth hormone, prolactin, TSH)
feedback loops
the release of hormones from the hypothalamus stimulates the pituitary gland to release hormones as well
- the pituitary hormones in turn stimulate the organs to release their hormones
- in the feedback loop, the hormones of the organs also influence the hypothalamus to lower the secretion of hormones
neural regulation
through cognitive observations, certain processes, normally regulated by hormones, may be controlled by neurons
experience-based responses
a third control on the hormonal activities of the hypothalamus is the brain’s response to experience
- neurons in the hypothalamus undergo a structural and biochemical change, just as cells in other brain regions do
lateral hypothalamus (in rats)
linked to the feeling of hunger
- if it is lesioned, there is aphagia (failure to eat)
ventromedial hypothalamus (in rats)
linked to the feeling of fullness
- if it is lesioned, there is hyperphagia (overeating)
osmotic thirst
occurs when the balance between moisture inside and outside a cell is disturbed
- it is then necessary to drink something that ensures that the concentrations are again in the right proportions
hypovolemic thirst
when there is too little fluid in your body
- we tend to want to drink something other than water, because water would dilute the solute concentration in the blood
organizing effects
effect during prenatal development (e.g. the influence of androgens on the masculinization of the brain)
activating effects
effects in the adult brain
- in females, oestrogen levels are linked to sexual behaivor
- in men, testosterone levels are linked to sexual behavior
subjective feelings
like fear, anger, love
- the amygdala and prefrontal cortex are important here
physiological responses
autonomic bodily reactions
- related to the hypothalamus
cognition
under the influence of the cerebral cortex, such as the evaluation of stimuli and thoughts about the experience
constructivist theory (James-Lange theory)
this theory states that the reaction precedes the emotion
- first there is the physiological change like an acceleration of the heart and then the brain interprets this change as an emotion
- empirically supported
Cannon-Bard theory
maintains that humans first see a stimulus, then feel an emotion, and then behave accordingly
- proven false
appraisal theory
views emotions as processes rather than states; emotional episodes are the coordinated/synchronized activities of multiple biological components
- an appraisal component
- somatic components
- a behavioral component
- a feeling component
limbic system
a brain region just beneath the neocortex which is important for emotional behavior, containing the following structures:
- cingulate gyrus
- hippocampus
- amygdala
- mammillary nucleus of the hypothalamus
cingulate gyrus
responsible for evaluating reward and punishment
hippocampus
responsible for memory and spatial navigation, and is vulnerable to the effects of stress
mammillary nucleus of the hypothalamus
involved in memory
amygdala
evaluates sensory information for emotional and motivational meaning
- connected to the hypothalamus and brainstem
- influences neural activity associated with emotions and species-typical behavior
electrical stimulation to the amygdala
leads to autonomic responses
- fear and anxiety
removal of both amygdalae
leads to Kluever-Bucy syndrome
- involves tameness and loss of fear, indiscriminate eating and sexual behaivor, overreacting to visual stimuli, examining objects with the mouth, and visual agnosia (inability to recognize objects)
anatomy of the frontal lobe
consists of the prefrontal cortex, premotor, and the motor cortex
prefrontal cortex
receives input from all sensory areas
- has many connections to the amygdala and hypothalamus
- damage has serious effects on social and emotional behavior
- damage can cause apathy and loss of initiative or drive, inability to plan and organize, resulting in bad decisions and radical personality changes
nucleus accumbens
in the basal ganglia and is important for both wanting and liking
- highly addictive drugs increase dopamine in the nucleus accumbens
