The recognition heuristic assumes that people make inferences based on the output of recognition memory. While much work has been devoted to establishing the recognition heuristic as a viable description of how people make inferences, more work is needed to fully integrate research on the recognition heuristic with research from the broader cognitive psychology literature. In this article, we outline four challenges that should be met for this integration to take place, and close with a call to address these four challenges collectively, rather than piecemeal.

In inductive inference, a strong prediction is the less-is-more effect: Less information can lead to more accuracy. For the task of inferring which one of two objects has a higher value on a numerical criterion, there exist necessary and sufficient conditions under which the effect is predicted, assuming that recognition memory is perfect. Based on a simple model of imperfect recognition memory, I derive a more general characterization of the less-is-more effect, which shows the important role of the probabilities of hits and false alarms for predicting the effect. From this characterization, it follows that the less-is-more effect can be predicted even if heuristics (enabled when little information is available) have relatively low accuracy; this result contradicts current explanations of the effect. A new effect, the below-chance less-is-more effect, is also predicted. Even though the less-is-more effect is predicted to occur frequently, its average magnitude is predicted to be small, as has been found empirically. Finally, I show that current empirical tests of less-is-more-effect predictions have methodological problems and propose a new method. I conclude by examining the assumptions of the imperfect-recognition-memory model used here and of other models in the literature, and by speculating about future research.

Errorless learning is an intervention that benefits memory performance in healthy older adults and a variety of clinical populations. A limitation of the errorless learning technique is that it is passive and does not involve elaborative processing. We report two studies investigating the added benefits of elaborative, self-generated learning to the errorless learning advantage. We also explored the mnemonic mechanisms of the errorless learning advantage. In both studies, older adults and individuals with amnestic mild cognitive impairment (aMCI) completed four encoding conditions representing the crossing of errorless/errorful learning and self-generated/experimenter-provided learning. Self-generation enhanced the errorless learning benefit in cued recall and cued recognition, but not in free recall or item recognition. An errorless learning advantage was observed for priming of target words, and this effect was amplified for participants with aMCI after self-generated learning. Moreover, the aMCI group showed significant priming of prior self-generated errors. These results demonstrate that self-generation enhances the errorless learning advantage when study and test conditions match. The data also support the argument that errorless learning eliminates the misleading implicit influence of prior errors, as well as the need for explicit memory processes to distinguish targets from errors. (JINS, 2009, 15, 704–716.)

Neuropathology in Huntington's disease (HD) known to project to areas that process olfactory information raises the questions of which olfactory function, if any, is most affected in HD, and how to explain such dysfunction in terms of olfactory sensitivity and cognition. These questions were studied by comparing HD patients and controls (matched for age, gender, and education) on absolute detection, intensity discrimination, quality discrimination, short-term recognition memory, and lexical- and picture-based identification for odor. Taste or vision were used as comparison modalities. The results suggest that whereas odor-recognition memory is not affected in patients with HD, these patients have impaired olfactory functioning with respect to absolute detection, intensity discrimination, quality discrimination, and identification. The three latter impairments were significantly explained by poor detection sensitivity. Odor identification was the function most affected. (JINS, 1995, I, 281–290.)

Patients with Alzheimer's disease (AD) exhibit a deficit in episodic recognition memory for odors. It is hypothesized that the higher rate of AD in women may be due to estrogen-deprivation in postmenopausal women. Research suggests that estrogen may help to minimize cognitive decline in AD as well as postmenopausal olfactory loss. The current study examined the effects of estrogen replacement therapy (ERT) on performance of a recognition memory task for olfactory and visual stimuli in women AD patients. Participants included 24 women AD patients who were ERT users and 77 women AD patients who never used ERT. Compared with the ERT non-users, the ERT users committed significantly less false-positive memory errors for olfactory stimuli, whereas performance for visual stimuli did not differentiate between ERT users and non-users. The results suggest benefits of ERT could help ameliorate the earliest symptoms of AD, olfactory dysfunction, and memory impairment. (JINS, 2006, 12, 400–404.)

Recognition and remote memory for odors, faces, and symbols were assessed in patients with pathologically confirmed Lewy body variant of Alzheimer's disease (LBV), patients with pathologically confirmed Alzheimer's disease (AD), and healthy elderly controls. On recognition memory tasks, LBV and AD patients showed significantly lower discriminability (d′) than controls, particularly for olfactory stimuli. However no significant differences were found in the bias measure (c). When participants rated familiarity (a proposed measure of remote memory) of olfactory stimuli LBV and AD patients reported significantly lower familiarity than controls. Familiarity ratings were significantly lower in LBV patients than in AD patients for olfactory, but not for visual stimuli. Consistent with prior reports, the LBV patients showed significantly poorer odor thresholds than AD patients. The results suggest that recognition memory for olfactory stimuli is impaired in LBV and AD. However, patients with LBV are more impaired than patients with AD on tasks requiring remote memory for olfactory but not visual stimuli. The findings suggest that odor memory tasks may be useful in the assessment of LBV and AD. (JINS, 2004, 10, 835–842.)

We investigated sex difference across a number of olfactory tasks. Thirty-six men and 35 women ranging in age from 19 to 36 years were assessed in 6 different tasks: absolute sensitivity for n-butanol, intensity discrimination, quality discrimination, episodic recognition memory for familiar and unfamiliar odors, and odor identification. No sex differences were observed in the tasks tapping primarily sensory acuity (i.e., odor sensitivity, intensity discrimination, and quality discrimination) or in episodic memory for unfamiliar odors. By contrast, women outperformed men in the tasks involving verbal processing (i.e., memory for familiar odors and odor identification). Interestingly, controlling for odor naming ability resulted in that the observed sex difference in episodic odor memory for familiar odors disappeared. This outcome suggests that women's superiority in episodic odor memory is largely mediated by their higher proficiency in odor identification.

The neurophysiological correlates of verbal and nonverbal memory have been extensively studied in adults, but comparable investigations of children are limited. A memory paradigm that is well established with adults is the repetition task, which finds a positive shift in the ERP waveform in response to repeated items, called the “repetition effect.” This is thought to represent the brain's memory trace for previously seen information and is reported predominantly at midline frontal and parietal electrodes. We recorded ERPs in thirteen 11- to 14-year old children during repetition tasks of words and faces. Performance was better and ERP latencies shorter for the word than the face task. Although a repetition effect similar to adults was seen at parietal electrodes with increased positivity to repeated items, increased negativity was observed at frontal electrodes; this suggests that the neural substrates of recognition memory continue to develop beyond 11 to 14 years of age. The demonstration of a repetition effect in children provides a basis for studying the neural correlates of specific childhood memory deficits.

A variety of processes contribute to successful recognition memory, some of which can be associated with spatiotemporally distinct event-related potential old/new effects. An early frontal and a subsequent parietal old/new effect are correlated with the familiarity and recollection subcomponents of recognition memory, respectively, whereas a late, postretrieval old/new effect seems to reflect an ensemble of evaluation processes that are set by the task context in which retrieval occurs. Both the early frontal and the parietal old/new effects are differentially modulated by the informational content (e.g., object forms and spatial locations) of recognition and seem to rely on brain systems damaged in amnesia. The late frontal effect appears to reflect prefrontal cortex activation. A neurophysiologically based model of recognition memory retrieval is presented and it is shown that coupling recognition memory subprocesses with distinct old/new effects allow examination of the time course of the processes that contribute to correct and to illusory memories. In conjunction with event-related functional magnetic resonance imaging activation patterns the brain systems recruited by various aspects of episodic memory retrieval can be identified.

M.E. Smith (1993) obtained event-related brain potentials (ERPs) from subjects performing a recognition memory task using “remember” (R) and “know” (K) judgments, and reported observing in the ERP a “neurophysiological manifestation of recollective experience” as a difference between the positive waveforms elicited by stimuli that yielded R and K judgments. We replicated his experiment and examined the componential structure of the R>K effect in two ways. First, we found that correction for P300 latency jitter eliminated the effect reported by Smith. Second, the application of principal component analysis indicated that the positive waveform elicited by the words in the test list was a P300. These analyses do not support the hypothesis that there is a new component (the “memory-evoked shift”) that is a specific manifestation of recollection.

We compared 7 mildly affected Huntington's disease (HD) patients to 7 age- and education-matched healthy controls (NC) on an odor detection test, the California Odor Learning Test, and the California Verbal Learning Test. Results demonstrated that odor detection sensitivity, but not group membership, accounted for significant variance in total olfactory learning. Both groups learned fewer items in the olfactory modality compared to the verbal modality, but retained a similar amount following a delay. No group differences were demonstrated for verbal recognition discriminability, but the HD group demonstrated significantly impaired odor recognition discriminability. Finally, odor detection provided excellent classification sensitivity and specificity between the patients and controls, suggesting that olfactory testing may provide a sensitive measure of the early disease process in HD. (JINS, 1999, 5, 609–615.)