Study 1: • 23 Ss viewed 265 pictures of food, attractive faces, symbols indicating monetary gains, and neutral objects.• Stimuli were rated on 14 dimensions including valence, arousal, desirability, interest, etc.• Ratings were subjected to Principal Components Analysis. two main components emerged – desirability (valence) and arousal. • Rewards were idiosyncratic; Ss had clear preferences for certain rewards, that differed across participants. • Using component scores we selected – for each subject – stimuli that were highly desirable for that individual, yet were matched in desirability across all subjects. Pre-Screening for Study 2: • 52 new Ss rated stimuli as in the study 1. • For 18 participants, we selected stimulus sets of faces, foods, and monetary gain values matched for valence (desirability) for that participant. Arousal did not differ across types.fMRI Participants: 9 male and 9 female undergraduate volunteers.Stimuli: 45 individually chosen (yet controlled) pictures:• 15 Food • 15 Faces• 15 MoneyEach presented twice, for a total of 90 trials. Trial Event Structure:Purpose: 1) Separate fMRI activity to pictures and rating; 2) Keep

subjects engaged; 3) Ratings provide manipulation check.

Are All Rewards Created Equal? An fMRI Study Comparing Different Reward TypesHedy Kober, Samuel Gershman, Kevin N. Ochsner, & Tor D. Wager

Department of Psychology, Columbia University

Introduction

The Present Study

Design

Brain Imaging Results

Summary & Conclusions

• Experimental work in animals and in humans has identified numerous neural structures involved in appetitive processes. • It has been shown that different types of appetitive cues (food, faces, money, pleasant odors) activate various subsets of this “reward system.” • Across experiments, little attention has been given to the importance of the type of reward used in each study. • Therefore, the extent to which reward-processing is domain-general or stimulus-specific is not yet clear.

The present study sought to determine whether reward representations depends upon common or distinct neural systems by varying:

1. The type of reward presented.2. The desirability of the reward, within of each

reward type.

• Post-scan ratings of stimuli show High>Medium>Low (F=29.78, p>.05).

Question 1: Do different rewards activate common or distinct neural mechanisms?

Answer 1: Reward processing depend on both common and unique mechanisms.• The Ventral Anterior Insula (vAI) and lateral

Orbitofrontal Cortex (OFC) were similarly activated by all reward types, regardless of the level of desirability, paralleling the equity in reported desirability across the various rewards.

• Other areas such as the Hypothalamus, Ventral Tegmental Area (VTA) and other limbic regions. showed reward-specific patterns of activation• VTA is significantly more active for faces than for

money, and more active for food than for money.• Hypothalamus is more active for faces than for

food.Question 2: Which areas are sensitive to variations in the

desirability of rewards?Answer 2: Regions sensitive to reward desirability were

specific to each stimulus type.• Very little overlap in regions sensitive to H>L.• Sub-clusters within Nucleus Accumbens (Nacc) seem

to modulate response for food more than for money or faces.

• Subregions in OFC sensitive to reward desirability for money and faces.

• These findings raise questions about whether activity in the Nacc and other limbic regions represent motivational value in a domain-general manner.

Prospects & Promise• FIR analyses may reveal differences in shape of

hemodynamic response across reward type/levels of desirability.

• Individual differences may further shed light on differential sensitivity to reward types across participants.

Acknowledgements

The authors thank NSF for Graduate Research Fellowship to the first author, and NIDA for grant 1R01-DA022541-01 to Kevin N. Ochsner.

Behavioral Results (manipulation check)

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Question 1: Do different rewards activate common or distinct neural mechanisms? To address this questions we performed two analyses:

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Food Face Money

Nucleus Accumbens (left ventral)

Food Money Face

Food Money Face

Food Face Money

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Nucleus Accumbens (right ventral)

Nucleus Accumbens (left dorsal) Nucleus Accumbens (right dorsal)

Hypothalamus Ventral Tegmental Area

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Lateral OFC

CerebellumBrain Stem

Ventral Anterior Insula (peri-piriform)

DMPFC

Insula

Nucleus Accumbens (left ventral) Nucleus Accumbens (right ventral)

Nucleus Accumbens (left dorsal) Nucleus Accumbens (right dorsal)

Hypothalamus Ventral Tegmental Area

DMPFC

Money

Faces

Food

Overlap of Two

Overlap of All

VMPFC Lateral OFC

2. We masked the RT>R activation maps for each of the three reward types by areas associated with emotional experience

Question 2: Which areas are sensitive to variations in the desirability of rewards? To address this questions we performed two analyses:

2. We masked the H>L activation maps within each reward types by areas associated with emotional experience

Scanning parameters: • 24 4mm slices on 1.5T GE Scanner.• TR: 2 seconds.• Pre-processing and RE analysis: FSL, SPM2, and robust regression at the 2nd level (Wager et al., 2005).

Caudate

Cerebellum

1. We compared activations in Reward Type > Rest (RT > R) contrasts in subcortical structural ROIs for regions shown to respond to rewards in previous studies.

1. We compared activations in High > Low (H>L) contrasts in subcortical structural ROIs for regions shown to respond to rewards in previous studies.

Anterior Insula

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SCAN UnitDept. of Psychology

1190 Amsterdam Ave.406 Schermerhorn HallNew York, NY 10027

www.scan.psych.columbia.eduDownload this poster: Download this poster: http://www.columbia.edu/cu/psychology/tor/

(Wager, T. D., & Feldman Barrett, L., in press.)

Thalamus

Food Face Money Food Face Money

Food Face Money

Food Face MoneyFood Face Money

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Ventral Striatum

Hypothalamus

Ventral Anterior Insula

(Wager, T. D., & Feldman Barrett, L., in press.)