Active versus latent representations: A neural network model of perseveration, dissociation, and decalage

Abstract

Children of different ages often perseverate, repeating previous behaviors when they are no longer appropriate, despite appearing to know what they should be doing. Using neural network models, we explore an account of these phenomena based on a distinction between active memory (subserved by the prefrontal cortex) and latent memory (subserved by posterior cortex). The models demonstrate how (a) perseveration occurs when an active memory of currently relevant knowledge is insufficiently strong to overcome a latent bias established by previous experience, (b) apparent dissociations between children's knowledge and action may reflect differences in the amount of conflict between active and latent memories that children need to resolve in the tasks, and (c) differences in when children master formally similar tasks (decalage) may result from differences in the strength of children's initial biases. The models help to clarify how prefrontal development may lead to advances in flexible thinking.

The processes underlying flexibility in childhood

“…According to the authors, these quicker responses reflect the higher strength with which switchers can actively maintain a representation of the newly relevant dimension as compared with perseverators, suggesting that maintenance capacity plays an important role in set shifting. These results are in line with Morton and Munakata's (2002;Munakata, 2001) active/latent representation theory, which assumes that set shifting is dependent on the relative strength of active representations of the task to be switched to and the latent representation of the task to be abandoned. According to this theory, set-shifting development would be a function of age-related increase in active-memory resources.…”

Generalizing the dynamic field theory of spatial cognition across real and developmental time scales

“…Importantly, the observed empirical pattern of variance is consistent with the DFT: variance is low near reference axes in our model due to the presence of continued reference input during the memory delay which helps stabilize peaks in SWM (much like the task input stabilized SWM peaks in simulations of the A-not-B model presented earlier). Both Munakata's PDP model and the CA model can capture aspects of the developmental profiles simulated here, and both models have been extended to other tasks not currently addressed within our framework (e.g., Huttenlocher, et al, 2000;Morton & Munakata, 2002). Importantly, however, these cases of generalization are closely tied to tasks that rely on the same or similar response types-selection of a limited number of choices in the case of Munakata's model, and estimation along a continuous dimension for the CA model.…”

“…Several theories have confronted the challenges of achieving generality with specificity, with varying levels of success (e.g., Cohen & Servan-Schreiber, 1992;Love, Medin & Gureckis, 2004;McClelland, McNaughton & O'Reilly, 1995;Morton & Munakata, 2002); here, we present one such theory, the Dynamic Field Theory (DFT) of spatial cognition (Spencer, Simmering, Schutte & Schöner, 2007). The dynamic field framework was originally developed to capture the dynamics of neural activation in visual cortex (Amari, 1977).…”

La représentation du but dans le contrôle exécutif chez l’enfant

“…Ces résultats suggèrent que le maintien du but joue non seulement un rôle essentiel dans le contrôle exécutif à l'âge adulte mais également durant l'enfance. D'ailleurs, l'accroissement des capacités de maintien actif des informations pertinentes pour la tâche à réaliser, et en particulier du but de la tâche, constitue le mécanisme principal de développement du contrôle exécutif dans l'un des modèles théoriques principaux ; celui des représentations actives et latentes (Morton & Munakata, 2002). Selon ce modèle, l'accroissement avec l'âge des connexions neurales récurrentes dans le cortex préfrontal permettrait à l'enfant de maintenir de plus en plus fortement le but de la tâche en mémoire de travail (mémoire active selon la terminologie des auteurs), résistant ainsi plus efficacement à l'interférence créée par les réponses spontanées mais inappropriées et sous-tendues par les régions postérieures.…”

“…Les autres (i.e., les enfants de 3 ans) continuent de répondre en fonction du biais latent (Morton & Munakata, 2002). En revanche, ce modèle ne permet pas d'expliquer les comportements dans les situations plus complexes qui requièrent non seulement de maintenir le but pertinent face à des informations distractrices, mais également de changer de buts à plusieurs reprises (Blaye & Chevalier, 2011 ;voir, cependant, la version révisée du modèle qui intègre un mécanisme de mise à jour du but par le biais des ganglions de la base, Chatham, Yerys, & Munakata, 2012).…”