L55 - Behavioral neuroscience

Question 1

Define motivation and what drives motivation?

Answer 1

Motivation is what initiates, maintains and directs behavior

– Internal states (e.g. thirst, hunger, pain)
– External stimuli (e.g. water, food, predator)

Question 2

Define instincts and what elicits it?

Answer 2

inborn (i.e. not learned) patterns of behavior common to a biological species

elicited by both internal state and external stimuli

Question 3

Describe the Drive Theory?

Answer 3

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

Question 4

Describe how the hypothalamus increases hunger arousal during fasting?

Answer 4

Low glucose in blood stream
» Activate median eminence of hypothalamus (no BBB)
» activate orexin neurons
» Increase arousal and food seeking

Question 5

Brain region involved in hypophagia?

Answer 5

Hypophagia can result from lateral hypothalamic lesions

Question 6

Neurological causes of Hyperphagia?

Answer 6

Ventromedial hypothalamic lesions (related to satiety)

Increased ghrelin
Leptin deficiency

Question 7

Which brain regions are involved in anorexia nervosa?

Answer 7

• 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

Question 8

Behavior is only motivated by the maintenance of homeostasis. T or F?

Answer 8

False

Certain stimuli (e.g. food) have incentive (rewarding) properties

> > motivate behavior even without an internal drive

Question 9

Describe classical conditioning?

Answer 9

if a conditioned stimulus is repeatedly paired with an unconditioned stimulus,

then the Conditioned Stimulus will eventually elicit the automatic response by itself

Question 10

Describe instrumental conditioning?

Answer 10

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)

Question 11

Which neurological pathways are involved in incentive salience (egaerness of action to get reward)?

Answer 11

dopamine

via the mesolimbic(ventral striatum) and mesocortical pathways

Question 12

Which brain areas are responsible for positive reinforcement of rewarding behavior/ addiction?

Answer 12

ventral striatum (nucleus accumbens) and lateral hypothalamus: forms REWARD CIRCUIT

Normally activated by natural rewards (i.e. food)

Question 13

Neurological effects of drugs causing addiction?

Answer 13

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

Question 14

Brain region responsible for associative learning of aversive stimuli?

Answer 14

Amygdala

Question 15

Describe negative reinforcement behavior?

Answer 15

behaviors that elicit aversive stimuli will become less frequent (punishment)

behaviors that reduce aversive stimuli will become more frequent

Question 16

Define the evolutionary function and neurological effects of anxiety?

Answer 16

• 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

Question 17

Define Phobias?

Answer 17

• extreme and irrational anxiety response to an object or situation
• causing avoidance of the feared object or situation

Question 18

Describe how learned helplessness manifests?

Answer 18

repeatedly exposed to aversive stimuli that cant be influenced or avoided

> > become inactive to hopeless situation, accept defeat, conserve resources, reflect and plan

Question 19

List 2 clinical questionnaires + 1 cognitive test for depression assessment?

Answer 19

Beck Depression Inventory, BDI
Hamilton Depression Scale, HAM-D

Stroop task

Question 20

Describe the stroop task?

Answer 20

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

Question 21

List the brain regions involved in control of emotions

Answer 21

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)

Question 22

Define negative rumination?

Answer 22

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

Question 23

How is behavior modulated by higher cognitive centers different from classical/ operant conditioned behavior?

Answer 23

Higher cognitive function = greater degree of flexibility and sophistication in behavior

Question 24

List some higher cognitive functions?

Answer 24

– Working memory
– Verbal fluency
– Abstract reasoning and planning (executive function)
– Social perception (empathy / theory of mind)
– Inhibition of primitive (instinctive) impulses

Question 25

Key brain structures for higher cognitive functions?

Answer 25

prefrontal cortex and association cortices, basal ganglia and thalamus

Question 26

Describe the formation of goal-focused behavior by diff. brain regions?

Answer 26

prefrontal cortex with working memory interacts with the basal ganglia

> > initiate goal-directed behaviors

Question 27

Describe how goal-directed behavior is reset to new tasks?

Answer 27

Dopaminergic input reports new salient rewards

> > opens “gate” for incoming information to prefrontal cortex

> > reset the working memory to new tasks

Question 28

Difference between schizophrenia and affective psychosis?

Answer 28

schizophrenia = psychosis accompanied by cognitive deficits

affective psychosis = psychosis accompanied by mood symptoms

Question 29

How does excess dopamine alter behavior and cause psychosis?

Answer 29

– Inappropriate incentive salience to neutral stimuli leads to delusions

– Impaired sensory gating leads to rapid switches in working memory and thought disorder

Question 30

List 2 tests for executive functions.

Answer 30

Wisconsin card sorting test

Tower tests for abstract planning