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This work was supported by the John Templeton Foundation. [email protected] The successful realization of future plans, prospective memory or PM, ...

The strategic allocation of working memory and episodic memory in prospective remembering: A neural network model Ida Momennejad*, Momchil Tomov*, Kenneth A. Norman, Jonathan D. Cohen Princeton Neuroscience Institute, Princeton University

III. Neural network model

YES

NO

NO

PM

YES

Einstein et al. 2005

V. WM capacity & strategic WM-EM balance - Low WM - High WM

OG RT

Prediction

Simulation: high EM

Cycle

VI. Commission errors

Commission errors: PM response is made outside PM context. We suggest (i) strong encoding of PM context or (ii) strong EM target-task association can trigger a bottom-up reaction to a former PM target. Over time, context activation & hence CEs diminish. i. High PM context ii. High EM association

Task 3 RT

b

1st PM RT

Simulation PM hitrate

PM hitrate

Human

Strengthening EM improves PM and compensates for low WM Brewer et al. 2010

OG RT (s)

Exp 2. Focal vs. nonfocal costs over time Human

Simulation

Block #

Block #

Emphasis

Emphasis

Exp 3. 1 target vs. 6 targets Human

No PM

Exp 5. After-effects after PM task is over, slower RT to a former target during 3rd task

Human

Conclusions

Simulation

PM

No PM

PM

Simulation

Einstein et al. 2005

Our mechanistic model combines WM & EM strategies to solve the prospective memory problem, & shows human-like regulation of planned action while perfomring ongoing tasks. Representations & dynamics derived from the model can be compared to patterns & dynamics of fMRI data from PM paradigms to test our proposed mechanism.

References & acknowledgments

- Target: correct task 3 - Target: commission error - Non-Target: correct

Low PM context & Low EM link

Focal Non-focal

OG RT

Correct resposnes:

EM

(n=24)

Exp 4. Individual differences in OG RT costs reflect low cost vs. high cost strategies (n=104)

Accuracy

SUBJECT math

WM

Task 3 RT

ANIMAL tortoise

Block order: * non-PM (baseline OG) * PM * non-PM (aftereffects)

Accuracy

BUILDING table

Activation

VEHICLE dog

WM control network: dynamics of LCAs (2)

Focal PM: OG task’s stimulus features are same as PM target’s Non-focal PM: Attention to different features for OG stimuli vs. PM target PM emphasis: Priority of PM vs. OG (e.g. PM more rewarding)

Task 3 RT

OG task: Category match PM task: Syllable match

Exp1. Focality X Emphasis

Simulation

OG RT (s)

EM

PM instruction Target: tor

Episodic control (hippocampus)

Human

PM hitrate

Task-set

II. Behavioral paradigm ANIMAL cat

WM control (PFC-parietal)

Context

Input-output mapping semantic/automatic network

Task 3 RT

The successful realization of future plans, prospective memory or PM, requires the agent to maintain and retrieve a goal for execution at a future time. PM poses a memory problem for periods during which the agent is occupied with other ongoing tasks (OG) while being responsive to target events that demand goal execution. We suggest a mechanistic account of how working memory (WM) and episodic memory (EM) strategies are integrated to strike the right balance between maintenance and retrieval when solving varieties of PM problem.

IV. Simulation of major behavioral phenomena

OG costs (ms)

I. Background

1- Einstein, G. O., McDaniel, M. A. et al. (2005). Multiple processes in prospective memory retrieval: factors determining monitoring versus spontaneous retrieval. JEPG. 2- Usher, M., & McClelland, J. L. (2001). The time course of perceptual choice: the leaky, competing accumulator model. Psychological Review. 3- Brewer et al. (2010). Individual differences in PM: Evidence for multiple processes supporting cue detection. Memory and Cognition. This work was supported by the John Templeton Foundation. [email protected]

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