Sources of dissociation in the forgetting trajectories of implicit and explicit knowledge

by Tamayo Osorio, Ricardo M.

Abstract (Summary)
In this dissertation I investigate dissociations in the forgetting patterns of implicit and explicit knowledge. I claim that this approach may provide significant constraints for the assumption that a single system or mechanism determines both implicit and explicit processes. In the theoretical part, I construe a definition of implicit knowledge as information learned and retrieved without intention. I also explain the general role of single dissociations in theories of implicit knowledge. And I present an overview of the main lines of research concerned with the functions, operation, development, neural substrates, and forgetting patterns of implicit knowledge. In general, I argue that comparing the forgetting patterns of implicit and explicit knowledge may be best regarded from a graded perspective and may usefully bridge the gap between research on implicit learning and implicit memory. In a series of 4 Experiments university students were exposed to environmental regularities embedded in artificial grammar (AG) and serial reaction time (SRT) tasks. To compare the forgetting patterns, participants’ implicit (motor-performance based) and explicit (recognition based) knowledge was assessed before and after a retention interval. Taken together, the results indicate that explicit knowledge decays faster than implicit knowledge in both AG and SRT tasks. Furthermore, an interference task introduced instead of a retention interval produced the same pattern of dissociations. Finally, I conducted a set of simulations to asses the ability of a single-system model (Shanks, Wilkinson, & Channon, 2003) to account for my experimental results. The simulations showed that the model best fits the empirical data by introducing changes in the parameters related to (a) the common knowledge strength (for implicit and implicit knowledge), and (b) the reliability for the explicit test. In sum, my dissertation (1) suggests a conceptual framework for implicit and explicit knowledge, (2) provides new empirical evidence of dissociations in their forgetting patterns, and (3) identifies specific boundary conditions for a single-system model.
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Bibliographical Information:


School:Humboldt-Universität zu Berlin

School Location:Germany

Source Type:Master's Thesis

Keywords:Implicit memory implicit learning forgetting interference dissociation


Date of Publication:01/07/2009

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