Remembering Can Cause Inhibition Retrieval-Induced Inhibition As Cue Independent Process

1. Remembering Can Cause InhibitionRetrieval-Induced Inhibition As Cue Independent Process Veling & Knippenberg, 2004

2. Background • Recent research has showed that remembering may cause forgetting(Anderson, Bjork, & Bjork, 1994) • This Term is referred to as retrieval-induced forgetting (Anderson et al., 1994)

3. The retrieval-induced forgetting paradigm • Participants memorize category-exemplar pairs (FRUIT- strawberry) • After study phase, participants perform retrieval practice on half of the exemplars of some of the studied categories. • After retrieval practice, participants receive categories as cues and are requested to recall as many exemplars as possible.

4. Experiment 1: methods • Purpose: • Show that retrieval-induced forgetting can be obtained using recognition latencies • participants: • Fifty-four undergraduate students from the University of Nijmegen

5. Experiment 1: methods • Procedure 1. Participants studied word pairs that belonged to one of the three categories and were informed that they would have to retrieve those word pairs later in the experiment (explicit memory task) 2. After study phase, participants received category cues followed by the first two letters of corresponding exemplars from the study phase (e.g., FRUIT - st___). 3. After retrieval phase, new or studied words were presented on computer screen and participants had to indicate as quickly as possible whether this word had been presented in the study phase.

6. Experiment 1: Results & Discussion • Dependent variable • participants’ median reaction latencies • Did retrieval-induced forgetting on recognition time occur? • Yes! Participants were slower in recognizing unpracticed exemplars from practiced categories relative to recognizing unpracticed exemplars from unpracticed categories • alternative interpretation: • participants may have retrieved the category to facilitate their response.

7. Experiment 2 • Purpose • Examine whether retrieval-induced forgetting could be found in an implicit test of memory • Participants • Thirty-nine undergraduate students from the University of Nijmegen

8. Experiment 2: Methods • The first two phases of Experiment 2 were virtually identical to Experiment 1. • The third phase in Experiment 2, the implicit memory test, was a lexical decision task. • Following the retrieval practice, participants were to indicate as quickly as possible whether a letter string was a word. • Why lexical decision? • Does not require any activation of the categories of the previously studied categories or involve an active retrieval process of the exemplars

9. Experiment 2: Results & Discussion • Dependent variable • participants’ median reaction times to assess whether retrieval-induced forgetting on lexical decision times had occurred • Did retrieval-induced forgetting on lexical decision time occur? • Yes! Participants were slower in deciding that unpracticed exemplars from practiced categories were words compared with both practiced exemplars and unpracticed exemplars from unpracticed categories thereby showing retrieval-induced forgetting on an implicit test of memory. • Also, this retrieval-induced inhibition is cue-independent

10. General Discussion • Retrieval of exemplars from a category leads to a reduction in the activation level of unpracticed exemplars from the same category • Retrieval-induced inhibition occurs in tasks in which exemplars of the experimental categories are presented with and without category cues