Delayed memory for complex visual stimuli does not benefit from distraction during encoding

Abstract

The covert retrieval model (McCabe, Journal of Memory and Language 58(2), 480-494, 2008) postulates that delayed memory performance is enhanced when the encoding of memoranda in working memory (WM) is interrupted by distraction. When subjects are asked to remember stimuli for an immediate memory test, they usually remember them better when the items are presented without distraction, compared to a condition in which a distraction occurs following each item. In a delayed memory test, this effect has been shown to be reversed: Memory performance is better for items followed by distraction than without. Yet, this so-called McCabe effect has not been consistently replicated in the past. In an extensive replication attempt of a previous study showing the effect for complex visual stimuli, we investigated five potential boundary conditions of the predictions of the covert retrieval model: (1) Type of Stimuli (doors vs. faces), (2) type of distractor (pictures vs. math equations), (3) expectation about task difficulty (mixed vs. blocked lists), (4) memory load in WM (small vs. large), and (5) expectation about the long-term memory (LTM) test (intentional vs. incidental encoding). Across four experiments we failed to replicate the original findings and show that delayed memory for faces and other complex visual stimuli does not benefit from covert retrieval during encoding - as suggested as being induced by distractors. Our results indicate that the transfer of information from WM to LTM does not seem to be influenced by covert retrieval processes, but rather that a fixed proportion of information is laid down as a more permanent trace.

Keywords: Covert retrieval; Long-term memory; McCabe effect; Working memory.

Fig. 1

Illustration of the Immediate Memory Paradigm. Participants were shown a single stimulus (door or face) and were tested with an old/new recognition task

Fig. 2

Immediate and delayed memory performance across the different stimulus types and task conditions in Experiment 1. Note. Error bars reflect 95% highest density intervals of the estimated posterior distributions for d-prime

Fig. 3

Immediate and delayed memory performance across mixed and pure blocks as well as task. Note. Error bars reflect 95% highest density intervals of the estimated posterior distributions for d-prime

Fig. 4

Immediate and delayed memory performance across set size 1 and 3 as well as task conditions in Experiment 3. Note. Error bars reflect 95% highest density intervals of the estimated posterior distributions for d-prime

Fig. 5

Illustration of the immediate memory paradigm of Experiment 4. Participants were shown three stimuli (faces), the color of the frame indicated whether it was a to-be-remembered face or not and were tested with an old/new recognition task

Fig. 6

Immediate and delayed memory performance across instructions to remember or forget as well as task conditions in Experiment 4. Note. Error bars reflect 95% highest density intervals of the estimated posterior distributions for d-prime