The time-course of the generation effect

Abstract

The generation effect, in which items generated by following some rule are remembered better than stimuli that are simply read, has been studied intensely over the past two decades. To date, however, researchers have largely ignored the temporal aspects of this effect. In the present research, we used a variable onset time for the presentation of the to-be-remembered material, thus providing the ability to determine at what point during processing the generation effect originates. The results indicate that some benefit from generation attempts occurs even when subjects have only a few hundred milliseconds in which to process the stimulus, but that more of the benefit occurs later. This finding suggests that the generation effect results from continuous or multiple discrete stages of information accrual or strengthening of memory traces over time, rather than from a single discrete increment upon final generation.The generation effect, first described by Slamecka and Graf (1978), is a robust phenomenon in which recall or recognition ofa stimulus list is enhanced ifa person must generate the list by using some rule (e.g., rhyming, synonym-antonym relations, multiplication) as opposed to simply reading the list. Theories describing this phenomenon include effort (see, e.g., Griffith, 1976; MeFarland, Frey, & Rhodes, 1980) or arousal (Jacoby, 1978); semantic activation (e.g., Graf, 1980;McElroy & Slamecka, 1982); relational processes (e.g., Donaldson & Bass, 1980;Rabinowitz & Craik, 1986); multiple-factor explanations (e.g., Hirshman & Bjork, 1988; McDaniel, Riegler, & Waddill, 1990;McDaniel, Waddill, & Einstein, 1988); and a procedural account (e.g., Crutcher & Healy, 1989;McNamara & Healy, 1995).To date, however, researchers have largely ignored the time-course of the generation effect. It is not clear whether the benefit from generation is derived from a continual strengthening ofmemory traces during the generation process as a whole, from a small number ofdiscrete changes during the course ofgeneration, or from a single discrete change in memory representation at the time when generation is completed. Slamecka and Fevreiski (1983) did study the related question of whether recall or recognition would be improved in the event of generation failures. They manipulated the difficulty ofan antonym generation and found that subsequent recall levels for stimuli that had been attempted but not fully generated were roughly as high as the levels for completely successful gen- -Accepted by previous editor, Geoffrey R. Loftus 135 erations, but that recall was much lower for stimuli that had only been read. Recognition tests showed intermediate levels of the generation effect for unsolved antonyms in this research. Slarnecka and Fevreiski interpreted these findings as evidence that generation in this task involved at least two processes: generation ofa semantic code and subsequent association of this code with a surface representation (an English word, in this case). According to this interpretation, the generation failures...

Encoding Variability and Cuing in Generative Processing

“…A particularly important implication of the present series of studies is that generative processing enhances the utilization of such encoding variability relative to the more passive processing required by read conditions. These findings thus support Smith and Healy's (1998) speculation that the Soraci et al (1994) multiplecue approach provides a potentially important explanatory framework for generative effects in problem-solving domains.…”

“…Thus the role of cuing for the wider empirical domain of generation conditions, including congruous encoding contexts, remains to be explored. This is particularly important given that other researchers (Smith & Healy, 1998) have utilized Soraci et al's multiple-cue hypothesis as a possible explanation for generative effects in more complex problem-solving encoding contexts.…”

“Aha” effects in the generation of pictures

“…In a series offive studies, Soraci et al (1994) provided strong evidence in support of this multiple-cue hypothesis for incongruous item generation effects. Recently, Smith and Healy (1998) reported enhanced recall for delayed solutions in certain problem-solving conditions and claimed that, consistent with Soraci et al's (1994) multiple-cue hypothesis, the additional encoding time facilitated cue activation. In summary, converging evidence from several studies supports the hypothesis that effort toward comprehension, especially in encoding contexts in which the solution is uncertain, induces the activation of alternative cues that can later facilitate recall.…”

A Procedural Explanation of the Generation Effect for Simple and Difficult Multiplication Problems and Answers

“…Moreover, this finding cannot simply be explained by the fact that generating correctly is critical to the magnitude of the generation effect because it was found that participants were equally likely to recall an answer that had been correctly generated as one that had been incorrectly generated. Similarly, Slamecka and Fevreiski (1983) found a generation effect for antonym pairs even when subjects failed to come up with the correct answer; and Smith and Healy (1998) found a generation effect for simple multiplication problems even when subjects did not have time to complete the generation process before the answer was provided. These results collectively suggest that the critical aspect of the generation effect is that the participants engage in the mental operations involved in generation and that those operations can be successfully reinstated at test.…”