*

Logic of our study2

Jarrod A. Lewis-Peacock1,2, Matthew R. Salesi3, Jonathan D. Cohen1,2, Kenneth A. Norman1,2

1Princeton Neuroscience Institute, 2Department of Psychology, 3Department of Computer Science, Princeton University

Behavioral performance4

“Prospective memory”1

Task & procedures3 MVPA: cross-validation (train test)5

Decoding the use of working memory & episodic memory in prospective remembering

Balance two simultaneous tasks

MVPA: trial-averaged decoding & behavior6

How do we remember to execute our plans at the appropriate time?

e.g., Think to yourself ... “I need to buy orange juice”

Working Memory active maintenance

Episodic Memory cue-based retrieval

(think aboutother stuff)

costly but reliable

cheap but unreliable

Bias strategy used for picture task

high proactive interference & easy lexical decisions (1-back)

Working Memory

low proactive interference & hard lexical decisions ( 2-back)

Episodic Memory (EMbias)

Assess fMRI for evidence of strategyUse multivariate pattern analysis (MVPA) to measure theactive, sustained retention of the target stimulus

Predictions:

MVPA readout should correlate with prospective memory performance more in WMbias trials than in EMbias trials

Episodic retrieval success effects in posterior parietalcortex should be greater in EMbias trials than in WMbias trials

1. Picture recognition2. Lexical decision (n-back)

(WMbias)

N=14 participants; 18-35 years old, healthy young adults

* Classification done separately for each subject, using L2-penalized logistic regression,in anatomically-derived voxel mask consisting of fusiform & parahippocampal gyri

Result - comparable performance in both conditions

Society for Neuroscience Annual Meeting, Washington, D.C., November 13-16, 2011

left Ang. Gyrus

Preliminary results suggesta dissociation of hits/misses

in left dlPFC (WMbias) & left Angular Gyrus (EMbias)

left dlPFC

* **

target2 s

mythbrain

jalp

probe12 s

delay2 s

probe22 s probe3

2 s

zrud

probeN2 s

N = {1, 2,..., 21}

feedback2 s iti

6 s

1-backlexical decisions

small set, repeatedpictures

pack

2-backlexical decisions

large set, trial-uniquepictures

tumbate

keace

WMbias

EMbias

scene(30)

-none-(30)

face(30)

WMbias WMbias WMbias EMbiasEMbiasEMbias

6 blocks (15 trials each), alternate condition (random 1st)

829.04

see: McDaniel & Einstein (2007); Reynolds, West, & Braver (2009); Gilbert (2011);

Lewis-Peacock, Drysdale, Oberauer, & Postle (in press)

Research funding provided by NIH grants R01 MH069456 & R01 MH075706

GLM7Result - classification is best when training &/or testing on WMbias trials

EM WM WM EM EM EMbias bias bias

WM WMbiasbias bias bias bias

WM WMbiasbias

WM EMbiasbias

bias

bias

bias

bias