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.
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