L55 - Behavioral neuroscience Flashcards
Define motivation and what drives motivation?
Motivation is what initiates, maintains and directs behavior
– Internal states (e.g. thirst, hunger, pain)
– External stimuli (e.g. water, food, predator)
Define instincts and what elicits it?
inborn (i.e. not learned) patterns of behavior common to a biological species
elicited by both internal state and external stimuli
Describe the Drive Theory?
mechanism for maintaining homeotasis: 3 parts:
- Need –a deviation from the normal range requiring correction (e.g. low blood glucose level)
- Drive –a state of tension in the nervous system induced by a need (e.g. hunger)
- Behavior –an action that reduces drive (e.g. eating) and returns the body to its normal range
Describe how the hypothalamus increases hunger arousal during fasting?
Low glucose in blood stream
» Activate median eminence of hypothalamus (no BBB)
» activate orexin neurons
» Increase arousal and food seeking
Brain region involved in hypophagia?
Hypophagia can result from lateral hypothalamic lesions
Neurological causes of Hyperphagia?
Ventromedial hypothalamic lesions (related to satiety)
Increased ghrelin
Leptin deficiency
Which brain regions are involved in anorexia nervosa?
- Eating is suppressed despite increased ghrelin and decreased leptin
> > Hypothalamus has less influence than cortical regions (e.g. insula, anterior cingulate, prefrontal cortex) in causing disorder
Behavior is only motivated by the maintenance of homeostasis. T or F?
False
Certain stimuli (e.g. food) have incentive (rewarding) properties
> > motivate behavior even without an internal drive
Describe classical conditioning?
if a conditioned stimulus is repeatedly paired with an unconditioned stimulus,
then the Conditioned Stimulus will eventually elicit the automatic response by itself
Describe instrumental conditioning?
Actions consistently followed by a reward tends to increase in frequency – positive reinforcement**
“Goal-directed”: reward elicits internal focus and eagerness of action (incentive salience)
Which neurological pathways are involved in incentive salience (egaerness of action to get reward)?
dopamine
via the mesolimbic(ventral striatum) and mesocortical pathways
Which brain areas are responsible for positive reinforcement of rewarding behavior/ addiction?
ventral striatum (nucleus accumbens) and lateral hypothalamus: forms REWARD CIRCUIT
Normally activated by natural rewards (i.e. food)
Neurological effects of drugs causing addiction?
Increase dopaminergic activity at ventral striatum, activating the reward circuit
> > positive reinforcement of drug use
> > increase frequency of drug use elicit craving
> > Drug use becomes less pleasurable and more compulsive
> > behavior being driven more by the dorsal striatum than the ventral striatum
Brain region responsible for associative learning of aversive stimuli?
Amygdala
Describe negative reinforcement behavior?
behaviors that elicit aversive stimuli will become less frequent (punishment)
behaviors that reduce aversive stimuli will become more frequent
Define the evolutionary function and neurological effects of anxiety?
- function= prepare against danger/ anticipation of aversive stimuli
- Somatic features: increased heart rate, hyperventilation, tingling sensations, dizziness, nausea, muscle tensionand tremor.
- Psychological features: worry, apprehension, agitation
Define Phobias?
- extreme and irrational anxiety response to an object or situation
- causing avoidance of the feared object or situation
Describe how learned helplessness manifests?
repeatedly exposed to aversive stimuli that cant be influenced or avoided
> > become inactive to hopeless situation, accept defeat, conserve resources, reflect and plan
List 2 clinical questionnaires + 1 cognitive test for depression assessment?
Beck Depression Inventory, BDI
Hamilton Depression Scale, HAM-D
Stroop task
Describe the stroop task?
measure depressed mood, by assessing whether reaction time is interfered with by emotional content of the word
e.g. the word SAD would have a relatively slower reaction time in a depressed subject
List the brain regions involved in control of emotions
1) prefrontal cortex (ventromedial prefrontal and anterior cingulate)
2) subcortical nuclei (amygdala and ventral striatum)
system regulated by input from dorsolateral prefrontal cortex (interact cognition and emotion)
Define negative rumination?
Patients with depression exhibit NEGATIVE COGNITIVE BIAS:
– Selective attention to negative events, negative memories
– Negative appraisal of trivial social cues
– Internal (self) attribution of failures
How is behavior modulated by higher cognitive centers different from classical/ operant conditioned behavior?
Higher cognitive function = greater degree of flexibility and sophistication in behavior
List some higher cognitive functions?
– Working memory
– Verbal fluency
– Abstract reasoning and planning (executive function)
– Social perception (empathy / theory of mind)
– Inhibition of primitive (instinctive) impulses
Key brain structures for higher cognitive functions?
prefrontal cortex and association cortices, basal ganglia and thalamus
Describe the formation of goal-focused behavior by diff. brain regions?
prefrontal cortex with working memory interacts with the basal ganglia
> > initiate goal-directed behaviors
Describe how goal-directed behavior is reset to new tasks?
Dopaminergic input reports new salient rewards
> > opens “gate” for incoming information to prefrontal cortex
> > reset the working memory to new tasks
Difference between schizophrenia and affective psychosis?
schizophrenia = psychosis accompanied by cognitive deficits
affective psychosis = psychosis accompanied by mood symptoms
How does excess dopamine alter behavior and cause psychosis?
– Inappropriate incentive salience to neutral stimuli leads to delusions
– Impaired sensory gating leads to rapid switches in working memory and thought disorder
List 2 tests for executive functions.
Wisconsin card sorting test
Tower tests for abstract planning
