Recallable but not recognizable: The influence of semantic priming in recall paradigms

Abstract

When people can successfully recall a studied word, they should be able to recognize it as having been studied. In cued-recall paradigms, however, participants sometimes correctly recall words in the presence of strong semantic cues but then fail to recognize those words as actually having been studied. Although the conditions necessary to produce this unusual effect are known, the underlying neural correlates have not been investigated. Across five experiments, involving both behavioral and electrophysiological methods (EEG), we investigated the cognitive and neural processes that underlie recognition failures. Experiments 1 and 2 showed behaviorally that assuming that recalled items can be recognized in cued-recall paradigms is a flawed assumption, because recognition failures occur in the presence of cues, regardless of whether those failures are measured. With event-related potentials (ERPs), Experiments 3 and 4 revealed that successfully recalled words that are recognized are driven by recollection at recall and then by a combination of recollection and familiarity at ensuing recognition. In contrast, recognition failures did not show that memory signature and may instead be driven by semantic priming at recall and followed at recognition stages by negative-going ERP effects consistent with implicit processes, such as repetition fluency. These results demonstrate that recall - long-characterized as predominantly reflecting recollection-based processing in episodic memory - may at times also be served by a confluence of implicit cognitive processes.

Keywords: Cued recall; Event-related potentials; Familiarity; Priming; Recollection.

Figure 1.

Mean number of and proportion of studied words recalled in Experiments 1, 2, and 5. In Experiment 1 and 5, the mean number of and proportion of studied words recalled is separated based on whether the words were recognized as old or not recognized (i.e., recognition failures). Error bars are plotted separately for mean number of recognized recalls and mean number of recognition failures respectively at the top of each bar. In total there were 24 potential words to recall in each experiment and condition, which would correspond to a proportion of 1.0. In Experiment 2, because there was no recognition phase, the mean number of and proportion of studied words recalled is all that can be reported. Error bars represent the standard error of the mean in all cases.

Figure 2.

Example of the S-1 Voice Key device used to collect digitized time stamps of response times of cued recall for semantic associates in the current study, concurrent with EEG recordings.

Figure 3.

Experimental paradigm of Experiment 4. Top: The study phase (encoding). A total of 144 words, divided into 6 blocks of 24 words, were presented one at a time. Participants were instructed to select the color of the word, represented by gray and white boxes that alternated positions on the screen. Bottom: The test phase (retrieval). Two-hundred and eighty-eight new words, split into 6 blocks of 48 words, were presented one at a time, followed by a recall prompt. Half of the words were semantic associates of studied words and the other half were semantic associates of unstudied words, which we treated as ‘new’ words. Participants were prompted to recall the first word from the study session that came to mind, and then to recognize that word as “old” (from the study session) or as “new” (not from the study session).

Figure 4.

Mean number of words and proportion of studied words recalled in (Figure 4A) and mean RT for recall and recognition (Figure 4B) in Experiment 4. In Figure 4A, the mean number of and proportion of studied words recalled is separated based on whether the words were recognized as old or not recognized (i.e., recognition failures). Error bars are plotted separately for mean number of recognized recalls and mean number of recognition failures respectively at the top of each bar. In total there were 144 potential words to recall, which would correspond to a proportion of 1.0. In Figure 4B, the mean RT to produce/recall a word and the mean RT to recognize a produced word is plotted separately for recognized recalls, recognition failures, and correct rejections. Error bars represent standard error of the mean in all cases.

Figure 5:

Recall-related Physiology. Top: ERPs of Recall Responses. Effects are shown for each of the six main electrode clusters analyzed, locations for which are illustrated in the representative topographic figure at the bottom. Dashed boxes indicate latencies which were found to exhibit significant effects at p <.05. Bottom: Topographic Maps of Recall Responses. Circles indicate where electrode clusters were found to be significantly different for each of the respective contrasts noted in the figure, below a threshold of p <.05.

Figure 6.

Figure 5: Recall-related Physiology. Top: ERPs of Recognition Responses. Effects are shown for each of the six main electrode clusters analyzed, locations for which are illustrated in the representative topographic figure at the bottom. Dashed boxes indicate latencies which were found to exhibit significant effects at p <.05. Bottom: Topographic Maps of Recognition Responses. Circles indicate where electrode clusters were found to be significantly different for each of the respective contrasts noted in the figure, below a threshold of p <.05.

Figure 7.

Summary Model of the ERP Data on Recall and Recognition Patterns. This illustrates the temporal sequence of activity as participants first process recall judgments for cued semantic associates, followed by old/new recognition judgments about the items that they just produced in the preceding recall response. Circles indicate where electrode clusters were found to be significantly different from correct rejections, below a threshold of p <.05.