Age and Sex Differences in the Effects of Stress on Decision Making

Mara Mather

University of Southern California

Overview

• Age differences in the effects of stress on decision making– Study 1: Driving game

• Sex differences in the effects of stress on decision making– Study 2: Balloon Analogue Risk Task (BART)– Study 3: fMRI of modified BART

Study 1 Design

Stress – hold hand in ice water for 3 minutes

Control – hold hand in warm water for 3 minutes

Mather, Gorlick, & Lighthall (2009), Psych Science

Study 1 Design

Stress – hold hand in ice water for 3 minutes

Control – hold hand in warm water for 3 minutes

18 minutes later…

Play a brief game involving risky decision making

Mather, Gorlick, & Lighthall (2009), Psych Science

Driving Game

Stressed older adults drove less time during the yellow lights than other participants.

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0.1

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0.9

1

Younger OlderMean proportion of trial spent driving

ControlStress

Mather, Gorlick, & Lighthall (2009), Psych Science

Stressed older adults stopped and restarted more frequently than control older adults.

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Younger OlderMedian number of stops per second spent

driving

ControlStress

Mather, Gorlick, & Lighthall (2009), Psych Science

For younger adults, stress has opposite effects on male and female decision strategies.

Study 1 Study 2 Study 3

Similar brain networks were active during the decision task across the four groups.

Control M Control F Stress M Stress F

Insula (+) X X X X

Cingulate (+) X X X X

MPFC lateral (+) X X X X

Inferior parietal (+) X X X X

vmPFC (-) X X X X

Hippocampus (-) X X X X

But there whether the putamen was involved in the decision network depended on both stress and sex.

Control M Control F Stress M Stress F

Putamen (+) X X

Thalamus (+) X

Precuneus (+) X

Caudate (+) X X

Lighthall, Sakaki, Vasunilashorn, Somayajula, Nga & Mather (in preparation)

Conclusions

• Acute stress affects decision making – but differently depending upon both age and sex.

• In Study 1, stress reduced older adults’ risk taking and increased stops/starts in the driving game.

• In three studies, stress increased sex differences in decision making strategies among younger adults.

• Stress was associated with increased activation in the putamen for males but decreased activation for females.