Problem Solving and the Brain

Behavioral Studies of Insight

• Metcalfe’s experiment (from earlier). – Ss. studied insight problems (e.g. algebra) as

well as non-insight problems– At 15 seconds intervals, ss. rated how close

they felt to solving the problem– Only for insight problems, ss. suddenly

increased warmness ratings before solving problem

• Perhaps insight is special? But how do we really know what really happens during insight?

Promise of Brain Imaging Studies

• Difficult to link behavioral data to internal processes -- e.g., do warmness ratings really show that insight occurs rapidly?

• With brain imaging techniques, we can get converging evidence for a special insight process. Does insight occur suddenly, in the brain, as behavioral data suggests?

• Jung-Beeman et al. (2004). Studied neural correlates of “aha” moment using fMRI and EEG

Jung-Beeman et al.

• Compound Remote Associate Problems

Example: pine, crab, sauce

Question: what word can form a familiar compound word or phrase with the each of these words?

Solution: apple

(pineapple, crabapple, applesauce)

Example Problems

Problem:

% correct responses within 15 seconds Answer:

1 high/district/house 55% ?2 pike/coat/signal 33% ?3 office/mail/hat 32% ?4 fly/clip/wall 32% ?5 wise/work/tower 13% ?6 baby/spring/cap 13% ?7 break/bean/cake 12% ?8 land/hand/house 3% ?

fMRI• Functional Magnetic

Resonance Imaging

• Measures cerebral blood flow (related to neural activity) in different areas

• Results are usually based on the difference in response between experimental and baseline condition

MRI scan

Experimental Setup

Measure brain response here

Ss. press button when they solved a problem

Ss. press button when they felt insight during problem solving

Areas showing greater fMRI signal for insight than non-insight solutions

increased activity in the right hemisphere anterior Superior Temporal Gyrus

EEG / ERP• EEG: Electroencephalography

• Electrodes placed at the scalp; measuring changes in voltage

• High temporal resolution, poor spatial resolution – good to measure when processes are initiated as opposed to where

Example of EEG

EEG Results

Measure high frequency oscillations in gamma band (> 30Hz)

For insight problems that were correctly solved, a burst of gamma frequencies 0.3 seconds were observed before the solution response

EEG Results

Animation of the last half second (from -0.5 to -0.2) of high-frequency electrical activity at the scalp prior to the button press indicating subjects had solved a problem with insight.

from: http://www.psych.nwu.edu/~mjungbee/PLoS_Supp.htm

Brain Studies of Moral Reasoning

The Trolley Dilemma

• A trolley is running out of control down a track. In its path are 5 people who have been tied to the track by a mad person. Fortunately, you can flip a switch which will lead the trolley down a different track. Unfortunately, there is a single person tied to that track. Should you flip the switch? If you do nothing, the trolley will kill five, but if you intervene it will kill only one. Should you “kill one person” to save five?

SWITCH

• “Save as many as you can.”• “The good of the many outweighs the good of

the few.”• “Act so that you provide the maximum benefit to

the maximum number of people.”

What justifies your judgment ?

The footbridge dilemma

• similar to trolley dilemma

• A runaway trolley threatens to kill five people. You are standing on a footbridge over the tracks, next to a large stranger. If you push the stranger onto the tracks, killing him, his body will prevent the train from reaching the others, saving them. Do you push?

• Most people answer yes to the trolley question, no to the footbridge question

• Perhaps what’s wrong with killing the large man to save five is that it would be using the one as a mere means for the benefit of others

Variant of trolley dilemma

As before, a trolley is hurtling down a track towards five people. As in the first case, you can divert it onto a separate track. On this track is a single large man. Without the body of this man, the trolley would, if turned that way, make its way to the other track and kill the five people.

If it wasn't for the presence of the large man, flipping the switch would not save the five. Should you flip the switch?

SWITCH

The Surgeon’s Dilemma

You are a surgeon with six patients. Five of them need major organ transplants, which you could easily do if you had access to transplant organs. The sixth, an ideal donor for all the relevant organs, has a cold. Should you kill one person to save five?

• Philosophers have puzzled over why people believe it is morally acceptable to sacrifice one life for five in one case, but unacceptable in the other

• Difficult to find a unifying set of principles that explains what is morally acceptable

The psychology of moral reasoning

• Prescriptive question: what is right and wrong? Philosophy/Ethics

• Descriptive question: what are happens during moral reasoning? psychology

– Traditional view (e.g. Kant): moral judgment is primarily a matter of formal reasoning.

– Recent insights (Haidt): moral thinking is highly intuitive and emotional, and only appears to be a product of careful reasoning because of people’s after-the-fact rationalizations of their thinking.

• Perhaps the thought of pushing somebody to death is more emotionally salient

• Hypothesis (Greene et al.): differences in emotional engagement determine difference in response

• Trolley dilemma: “impersonal” moral dilemma.

• Footbridge dilemma: “personal” moral dilemma. requires active personal involvement

Recent Brain Imaging Insights

• Greene et al.: performed brain imaging experiments to reveal differences in the way the emotional circuits in brain are activated during moral reasoning.

fMRI Results

• Trolley dilemma: “impersonal” moral dilemma

activated memory areas

• Footbridge dilemma: “personal” moral dilemma requires active personal involvement

activated brain areas associated with emotion

Behavioral Results

• Footbridge dilemma activates immediate emotional response

• A few subjects still say “appropriate”.

• These response times should be slow because the response is “incongruent” with the immediate emotional response

• Results do not show how to reason correctly

• They show what happens during reasoning -- intuitive emotional reactions affect moral judgments