Lecture 12- Decision Making

Question 1

What is decision making?

Answer 1

A decision involves the selection of one option among several. It
typically involves the evaluation of the expected outcomes
associated with each option.

The subjective value of an item is made up of multiple variables
that include payoff amount, context, probability, effort/cost,
temporal discounting, novelty and preference.

Cognition is difficult and costly, partially because of peoples’
limited processing capacity.

Question 2

What is the Dual Systems Model of Decision-Making?

Answer 2

System 1: doesn’t require high level thinking (like heuristics)
-Processes of an experiential-affective nature
-Predominantly automatic
-Associative
-Rapid
-Undemanding

System 2: requires high level thinking
-Rational and analytic in nature
-Controlled
-Deliberative
-Rule-based
-Slow
-Conscious

Question 3

What do we consider when using system 2 to make rational decisions?

Answer 3

Payoff, Probability, Cost, Context, Preference……

-Look at external factors, then internal factors, then integrate these factors in deciding two possible courses of action. Comparison of these options then results in an outcome.

Question 4

What is temporal discounting?

Answer 4

-Involves weighing up a reward of certain amount now or waiting and receiving more later
-Temporal discounting refers to the fact that we devalue the reward later in order to feel okay about accepting the reward now
-The more time we need to wait to get the reward the more it’s subjective value decays (the more discounting occurs)

Question 5

What does temporal discounting curve look like in different groups of participants? What does this reveal?

Answer 5

-Those with an orbitofrontal lesion are a lot faster to decay the value of the later reward with patience running out after 2 weeks
-They are therefore much more likely to accept an immediate reward then weight.

Question 6

What does the idea of temporal discounting relate to?

Answer 6

-How long one should exploit a depleting resource before moving on i.e. patches of food in an environment
-Known as the exploit/ explore contrast

Question 7

In the exploit/ explore contrast when is the optimum time to move on from a patch?

Answer 7

-When instantaneous energy intake from the patch is equal to the
habitat average
-This is known as the Marginal Value Theorem (Charnov, 1974) as there there is no value in exploiting the patch any longer as from now on you will be
gaining less energy than you could from other patches. This means it is time to start exploring.

Question 8

Does Marginal Value Theorem apply for things other that food patches in an environment?

Answer 8

-Yes, works for social situations and also just general human cognition e.g. the balance between trying to find information on one webpage and exploring/ doing a new search for information

Question 9

What is the role of the Anterior Cingulate Cortex in patch leaving?

Answer 9

-Anterior Cingulate Cortex neurons encode value and firing is related to patch leaving
-There is a specific firing rate that corresponds to leaving (double rate from the baseline)

Question 10

What area of the brain is invovled in emotional decision making?

Answer 10

The Amygdala

Question 11

What does damage to the amygdala result in?

Answer 11

Damage to the anterior temporal lobes, including the
amygdala, produces the Kluver-Bucy syndrome:

-consumption of almost anything
-increased sexual activity
-investigate objects with the mouth
-a lack of fear

Question 12

What did a comparison between those more than 200 miles from 9/11 and those 9/11 exposed (less then 1.5 miles) show in regards to amygdala activation?

Answer 12

-Even three years later those exposed to 9/11 had a much greater difference in response (amygdala activation) between being shown calm and fearful faces
-This shows that being invovled in a traumatic experience can causes changes in the amygdala altering fear response

Question 13

What system of the dual process in decision making is more based on instinct?

Answer 13

System 1: it’s more automatic not rational. The body informs you of correct decision instead of thinking through. This may be conscious or unconscious.

Question 14

Where is emotional processing in the amygdala projected to?

Answer 14

ventromedial prefrontal cortex and anterior cingulate

Question 15

What case study shows vmPFC (ventromedial prefrontal cortex) involvement in emotional processing?

Answer 15

Phineas Gage - vmPFC lesion - fitful, irreverent, indulging at times in the grossest profanity, impatient of restraint or advice when it conflicts with his desires

Question 16

How is the thalamus connected to the amygdala for emotional processing? What does this allow?

Answer 16

-Direct pathway.
-Doesn’t go through complete complex processing but is enough to produce a rapid response (reflex like)

Question 17

What is the downfall with fast/ crude responses?

Answer 17

Like heuristics most the time they are fine and will keep you safe, however, occasionally because not fully reasoning it can lead to mistakes

Question 18

What did the anticipated pleasantness of both future events and autobiographical memories correlate with?

Answer 18

vmPFC (OFC) activation (Dixon et al., 2017)

Question 19

What is Damasio’s Somatic Marker Hypothesis (SMH)?

Answer 19

When faced with complex decisions, we make choices that are in
our best interest only after properly weighing potential short-term
and long-term outcomes (this is system 2: slow)

A key idea of the SMH is that when these outcomes are
ambiguous or uncertain, then emotions and feelings are essential
to making a decision (system 1: fast)

The VMPC (particularly orbitofrontal) is critical for triggering
various bodily changes (somatic states) in response to stimuli such
as cues for reward or punishment.

In other words, Somatic markers facilitate decision making by influencing potential responses via their affective value

Question 20

In Damasio (1994) what did patients with ventromedial frontal cortico damage fail to do?

Answer 20

-Patients with ventromedial frontal cortical damage failed to show autonomic emotional responses (line was flat) to arousing stimuli (innate responses e.g. to a loud noise were still intact meaning that the autonomic nervous system is working).

-Measured emotional response via galvanic skin response (2 electrodes measuring resistance , difference between them= conductance) and changed according to arousal.

Question 21

What is the Iowa Gambling Task (Bechara et al, 1994; 1999)? What were the key findings?

Answer 21

Two decks:
-Disadvantageous deck: high risk, long-term loss (win $1000, lose $3100)
-Advantageous deck: low risk, long-term gain (win $500, lose $330)

-13 control subjects, 5 amygdala damage, 5 VMF damage. Skin conductance response (SCR) measured from palms.

-The control patients quickly swap from the disadvantageous deck to the advantageous deck. While those with amygdala damage and VMF damage don’t swap sticking to using the disadvantageous deck.

-The galvanic skin response showed that those in the control group had a much larger response (pre picking card) for both the advantageous and disadvantageous decks (more pronounced for disadvantageous) suggesting that the nervous system is giving signals about which deck to use. In other words, they feel more anxious using the high stakes deck so swap. Those with amygdala or VMF damage however, have much less of a galvanic skin response overall and not much difference between the two deck types.

-The skin conductance response to punishment in the disadvantageous deck was also a lot bigger comparative to the advantageous deck for normal participants. Not much difference between the decks was shown for the other groups or for reward in the normal group.

Question 22

What are somatic markers? Under what type of decision making can they operate?

Answer 22

-Somatic markers (SM) are a special instance of feelings generated from secondary emotions.

-Those emotions and feelings have been connected by learning to predicted future outcomes of certain scenarios.

-In simple language somatic markers are feelings in the body associated with emotions e.g. racing heartbeat for anxiety or nausea for disgust

-SM can operate in both type 1 and type 2 mode

Question 23

The lateral side of the prefrontal cortex is invovled with…
The medial side of the prefrontal cortex is invovled with…

Answer 23

-Lateral= cold processes (more classic thinking of cognition without input of emotion)
-Medial= hot processes (where emotions do influence/ come into play)

Question 24

Are there circumstances where prefrontal cortex is inhibited?

Answer 24

Alcohol intoxication

Question 25

Does alcohol reduces PFC activity in go/no go task?

Answer 25

-Placebo= most activation, moderate= a little activation, high dose of alcohol= not much activation
-Prefrontal activation in the go/no task occurs during false alarms where you respond to an X but not to K
-The less activation there is in prefrontal cortex the more dangerous it becomes to carry out tasks like driving (why there is a blood-alcohol limit).

Question 26

Other than alcohol what is another situation where prefrontal cortex is inhibited?

Answer 26

Threat/Fear:
Reactive Fear - fast escape decisions (this one is where prefrontal cortex is inhibited)
Cognitive Fear – Slow, strategic escape (this is where there is build up and rationale/ the prefrontal cortex comes in)

Question 27

What did Wendt et al (2017) investigate?

Answer 27

The effects of approaching threat:
-Shown a visual stimulus that gets bigger and bigger (progressing from stage 1 to 5) across a 15 second time span.
-At stage 5 (where circle hits edges of box) must press button within ~ 240 ms in order to prevent aversive stimulus (tap on toe)
-fMRI scanning occurs during experiment and shows that approaching threat inhibits vmPFC activity

Question 28

What experiment was used to show Fear and it’s role in modulating information acquisition for decision-making?

Answer 28

-Frey et al 2014
-Sampling before oral surgery (fear group) or waiting for a comedy show (happy group)
-Each button (A/B) has a different probability of payoff/ loss and a different outcome value. Sample to work out which is best then make choice.
-Sample as many times as you like. Then choose which button you like.
-Fearful group tended to sample more before choosing, but were less likely to switch between buttons

Question 29

To summarize what does immediate threat cause?

Answer 29

-Inhibit prefrontal activity
-Compromise choice behavior because of inflexibility

This is not always helpful, particularly in circumstances that we haven’t experienced in our evolutionary history

Question 30

How has evolution shaped our response to unexpected threat?

Answer 30

-Fight, Flight or Freeze

Fight:
gaze oriented to threat
body oriented to threat
arms oriented to threat

System 1 response?
Fewer options considered, limited analysis