An interference account of cue-independent forgetting in the no-think paradigm

Abstract

Memory suppression is investigated with the no-think paradigm, which produces forgetting following repeated practice of not thinking about a memory [Anderson MC, Green C (2001) Nature 410:366-369]. Because the forgotten item is not retrieved even when tested with an independent, semantically related cue, it has been assumed that this forgetting is due to an inhibition process. However, this conclusion is based on a single stage to recall, whereas global memory models, which produce forgetting through a process of interference, include both a sampling and a recovery stage to recall. By assuming that interference exists during recovery, these models can explain cue-independent forgetting. We tested several predictions of this interference explanation of cue-independent forgetting by modifying the think/no-think paradigm. We added a condition where participants quickly pressed enter rather than not thinking. We also manipulated initial memory strength and tested recognition memory. Most importantly, learning to quickly press enter produced as much cue-independent forgetting as no-think instructions. Demonstrating the adequacy of two-stage recall, a simple computational model (SAM-RI) simultaneously captured the original cue, independent cue, and recognition results.

Fig. 1.

Current methodology as adapted from the TNT paradigm by Anderson and Green (2).

Fig. 2.

One-stage (Upper) versus two-stage (Lower) models of cued recall. For both models, the initially learned association between “Plane” and “Doctor” is represented by solid lines. The dashed lines between “Plane” and “Other Recovery” represent the newly learned association during suppression training, as in the no-think and press-enter conditions.

Fig. 3.

Original cue recall accuracy by memory strength and suppression task. The circles show data fits with the SAM-RI model based on the parameters reported in the text. Error bars present plus and minus one SEM.