Gaze control and recollective experience in face recognition

In two experiments, we examined the relation between gaze control and recollective experience in the context of face recognition. In Experiment 1, participants studied a series of faces, while their eye movements were eliminated either during study or test, or both. Subsequently, they made remember/know judgements for each recognized test face. The preclusion of eye movements impaired explicit recollection without affecting familiarity-based recognition. In Experiment 2, participants examined unfamiliar faces under two study conditions (similarity vs. difference judgements), while their eye movements were registered. Similarity vs. difference judgements produced the opposite effects on remember/know responses, with no systematic effects on eye movements. However, face recollection was related to eye movements, so that remember responses were associated with more frequent refixations than know responses. These findings suggest that saccadic eye movements mediate the nature of recollective experience, and that explicit recollection reflects a greater consistency between study and test fixations than familiarity-based face recognition.     

Attention and recollective experience in recognition memory

The functional relation between recognition memory and conscious awareness was assessed in an experiment in which undivided attention at study was compared with two divided attention conditions, one more demanding than the other. When recognizing a word from the study list, subjects indicated whether they could consciously recollect its prior occurrence or recognized it on some other basis, in the absence of conscious recollection. Divided attention at study progressively impaired word recognition accompanied by conscious recollection. Recognition in the absence of conscious recollection was not affected by divided attention. These findings are interpreted as providing further support for the idea that recognition memory entails two distinct components, one based on associative and contextual information, the other based on a "traceless" awareness of familiarity.     

Cognitive effort and recollective experience in recognition memory

The difficulty of the cognitive operations required to process study items was manipulated in two experiments investigating recollective experience. In subsequent recognition tests, subjects indicated whether their recognition judgements for items processed in these tasks were based on recollection ("remember" responses) or on familiarity ("know" responses). In Experiment 1 target items were presented in the context of a category decision task. It was found that remember responses increased with the difficulty of the category decision. For positive instances, remember responses were greater for items of low instance frequency than for items of high instance frequency, while for negative instances remember responses were greater for items from similar categories than for items from dissimilar categories. These effects were not present in know responses. In Experiment 2, remember responses were more frequent when study items had been presented in the form of anagrams to be solved than when they had been presented in the form of words to be read aloud. The incidence of know responses was not affected by the format in which study items were presented. Source judgements were also more accurate when recognition was based on recollection. It is argued that the type of conscious awareness experienced during recognition is determined by the knowledge activated by items presented in the recognition test, which in turn is determined by the nature of the operations engaged at encoding.     

Distinctiveness,typicality, and recollective experience in face recognition: A principal components analysis

In this study, participants rated previously unseen faces on six dimensions: familiarity, distinctiveness, attractiveness, memorability, typicality, and resemblance to a familiar person. The faces were then presented again in a recognition test in which participants assigned their positive recognition decisions to either remember (R), know (K), or guess categories. On all dimensions except typicality, faces that were categorized as R responses were associated with significantly higher ratings than were faces categorized as K responses. Study ratings for R and K responses were then subjected to a principal components analysis. The factor loadings suggested that R responses were influenced primarily by the distinctiveness of faces, but K responses were influenced by moderate ratings on all six dimensions. These findings indicate that the structural features of a face influence the subjective experience of recognition.     

Perceptual asymmetries in face recognition

Four experiments were carried out to investigate perceptual asymmetries in face recognition. Perceptual asymmetries favoring the half-face on the observer's left were found under free viewing conditions for both unfamiliar faces (Experiment 1) and famous faces (Experiment 3). For unfamiliar faces, this asymmetry was not obtained when fixation was controlled by presenting faces tachistoscopically (Experiment 2). For famous faces, the perceptual asymmetry favoring the half-face normally seen on the left did not appear to be retained in memory (Experiments 3 and 4). Asymmetries in face perception have been explained in terms of a direct access model of laterally effects. However, these results raise the possibility that asymmetric scanning or attentional factors may be important.     

Forgetting in recognition memory with and without recollective experience

Retention interval was manipulated in two recognition-memory experiments in which subjects indicated when recognizing a word whether its recognition was accompanied by some recollective experience ("remember") or whether it was recognized on the basis of familiarity without any recollective experience ("know"). Experiment 1 showed that between 10 min and 1 week, "remember" responses declined sharply from an initially higher level, whereas "know" responses remained relatively unchanged. Experiment 2 showed that between 1 week and 6 months, both kinds of responses declined at a similar, gradual rate and that despite quite low levels of performance after 6 months, both kinds of responses still gave rise to accurate discrimination between target words and lures. These findings are discussed in relationship to current ideas about multiple memory systems and processing accounts of explicit and implicit measures of retention.     

Mediators of age-related differences in recollective experience in recognition memory

This study examined states of awareness with the Remember/Know paradigm during verbal recognition memory in young and old adults. Following the presentation of a word list, subjects undertook a recognition test and indicated whether they could consciously recollect its prior occurrence (R) or recognize it on some other basis, without conscious recollection (K). In this individual-difference approach we also incorporated various processing-speed and working-memory measures to study the link between aging, states of awareness and processing resources. The results revealed that, compared to younger adults, older adults exhibited a decline in the amount of R responses during the recognition test whereas the amount of K responses did not change. Structural equation modeling indicated that a slower processing speed associated with a limited working-memory capacity is a key to explaining age-related variance in conscious recollection. The findings offer further support for the distinction between remembering and knowing and for the processing-resources hypothesis of aging.     

Dissociative effects of alcohol on recollective experience

This article reports a study comparing the effects of a single dose of alcohol with a matched placebo drink on recognition memory with and without conscious recollection. A double-blind, cross-over design was used with healthy volunteers who were all social drinkers. Processing depth at study was manipulated using generate versus read instructions. Conscious recollection at test was assessed using the remember-know-guess paradigm (Gardiner, 1988; Tulving, 1985). Alcohol significantly reduced conscious recollection (remember responses) but had no effect on recognition in the absence of conscious recollection (know responses). False alarms rates were low and unaffected by alcohol. Previous findings that generation effects are found only for remember responses were closely replicated. A further dissociation of the generation effect occurred between treatments in that deeper processing at study facilitated recognition on placebo but not on alcohol. That both alcohol and depth of processing produce dissociative effects on recollective experience provides further evidence that remembering and knowing reflect distinct memory systems.     

Perceptual learning in face processing: Comparison facilitates face recognition

Theoretical analyses of perceptual learning suggest that comparison between similar stimuli aids subsequent discrimination between them. The current studies examined whether the opportunity to compare a target face to other similar faces during a preexposure phase facilitated performance on a matching task. Performance was better when the target face had been presented in alternation with similar comparator faces than if that target had not been exposed before test. Exposure to the target face without comparators, or exposure alternating with dissimilar faces, improved performance relative to the nonexposed control but performance was not as good as when target exposure was given in alternation to similar comparison faces. The effects were not influenced by image changes between exposure and test. It is suggested that exposure to a face in comparison to similar stimuli focuses the central representation of a face on its unique features. In practical terms these results suggest that reliable identification of an individual from their photograph would be improved by viewing that photograph in comparison with photographs of similar people.     

Perceptual expertise and the plasticity of other-race face recognition

In this paper, we argue that our ability to recognize own-race faces can be treated as a form of perceptual expertise. Similar to object experts (e.g., birdwatchers), people differentiate own-race faces at the subordinate level of categorization. In contrast, like novices, we tend to classify other-race faces at the basic level of race. We demonstrate that, as a form of perceptual expertise, other-race face recognition can be systematically taught in the lab through subordinate-level training. When participants learn to quickly and accurately differentiate other-race faces at the subordinate level of the individual, the individuating training transfers to improved recognition of untrained other-race faces, produces changes in event-related brain components, and reduces implicit racial bias. Subsequent work has shown that other-race learning can be optimized by directing participants to the diagnostic features of a racial group. The benefits of other-race training are fairly long-lived and are evident even 2 weeks after training. Collectively, the training studies demonstrate the plasticity of other-race face recognition. Rather than a process that is fixed by early developmental events, other-race face recognition is malleable and dynamic, continually being reshaped by the perceptual experiences of the observer.     

The self and recollective experience

Three experiments investigated the hypothesis that self-reference at encoding increases the probability of recollective experience in recognition memory. In all three experiments separate groups of subjects studied words naming personality traits. One group judged the self-relevance of the traits, the other groups performed orientating tasks low in self-reference. In a recognition test subjects first identified old items and then indicated which of these were accompanied by recollective experience ('remember' responses) and which were recognized on some other basis ('know' responses). No reliable differences in overall recognition performance between self-referent and semantic encoding tasks were observed. However, subjects who encoded trait adjectives with reference to the self produced reliably more remember responses and few know responses than subjects who had encoded the items in the low self-referent tasks. Experiment 1 demonstrated a self-reference effect in recognition accompanied by recollective experience after 1-hour retention interval, while Experiment 2 found this effect to persist over a 24-hour retention interval. Experiment 3 demonstrated that this self-reference effect is obtained under incidental as well as under intentional learning conditions. Taken together these findings demonstrate the importance of self-reference as a factor in determining the likelihood that recognition judgements will be accompanied by recollective experience.     

Expertise and recollective experience: recognition memory for familiar and unfamiliar academic subjects

Two experiments investigated whether expertise effects in recognition memory could be found for different academic subjects. The roles of subjective experience and repetition on such effects were also explored. Experiment 1 showed that overall recognition memory was greater for familiar than for unfamiliar academic words (the expertise effect). Additionally, this effect was attributable to the subjective experience of remembering rather than knowing. Experiment 2 showed that repetition of stimulus items at study eliminated these expertise effects. Previous research has generally failed to find expertise effects in overall recognition memory. The present findings show that expertise effects do occur in overall recognition memory and are associated with the richer memorial experience of remembering rather than knowing. Copyright © 2005 John Wiley & Sons, Ltd.     

Functional aspects of recollective experience

The functional relationship between recognition memory and conscious awareness was examined in two experiments in which subjects indicated when recognizing a word whether or not they could consciously recollect its prior occurrence in the study list. Both levels of processing and generation effects were found to occur only for recognition accompanied by conscious recollection. Recognition in the absence of conscious recollection, although less likely, was generally reliable and uninfluenced by encoding conditions. These results are consistent with dual-process theories of recognition, which assume that recognition and priming in implicit memory have a common component. And they strengthen the case for making a functional distinction between episodic memory and other memory systems.     

Similarity effects in face recognition

Three experiments are described which examine the effects of similarity on face recognition using a new application of hierarchical clustering analysis (HCS). Experiments I and II employed a within-groups design where subjects attempted to recognize targets among decoys from the same and different cluster to the target. Common cluster membership accounted for 72% and 84%, respectively, of all false alarms in the two experiments. Absolute error rates were affected by the number of targets actually present in the array and the style of the instructions given to subjects but were not influenced by whether successive or simultaneous test presentation was employed. Experiment III used a between-subject design where targets were embedded in arrays composed from same or different clusters. False alarm rates were significantly higher for the same cluster condition, but hit rates were unaffected by recognition context. The significance of these findings for theories of face identification is discussed.     

Emotionality,distinctiveness, and recollective experience

Two experiments investigated the effects of emotional stimuli on recollective experience in recognition memory. In Experiment 1, words judged to evoke a positive emotional response (e.g., warmth, freedom) or a negative emotional response (e.g., mucus, corpse) were associated with more “remember” responses than emotionally neutral words (e.g., crate, border) when presented in mixed lists. This effect was stronger with negative words than with positive words. In Experiment 2 the effects of emotional stimuli were eliminated when participants studied pure lists of either all emotional or all neutral words. These findings are discussed in relation to Rajaram's (1996) distinctiveness account of recollective experience.     

Components of recollective experience in cued recall

Components of recollective experience were examined in relation to cue effectiveness by presenting subjects with their own or someone else's associations as retrieval cues. When recalling an item, subjects indicated whether they consciously recollected its prior occurrence ("remembering") or recalled it on some other basis, in the absence of conscious recollection ("knowing"). The results showed that cue compatibility (self-generated vs. someone else's cues) and retention interval (immediate vs. delayed test) selectively impaired retention accompanied by recollective experience, as measured by remember responses, but had reduced effects in the absence of recollective experience, as measured by know responses. The results are discussed in terms of variables dissociating judgments of recollective experience.     

Differential time-dependent effects of emotion on recollective experience and memory for contextual information

Emotion has been suggested to slow forgetting via a mechanism that enhances memory consolidation. Here, we investigate whether this time dependent process influences the subjective experience of recollection as well as the ability to retrieve specific contextual details of the study event. To do so we examined recognition for emotional and neutral pictures at two retention intervals and collected remember/know reports and reports about the task that had been performed with the item during encoding. Recollective experience was enhanced for emotional compared to neutral photos after a 24-h delay, but not immediately after encoding. In contrast, memory for the task performed during encoding did not differ between emotional and neutral photos at either time point. The findings indicate that emotion slows the effects of forgetting on the recollective experience associated with studied events, without necessarily slowing the forgetting of specific contextual details of those events.     

Comparing recollective experience in true and false autobiographical memories

This study investigated whether true autobiographical memories are qualitatively distinct from false autobiographical memories using a variation of the interview method originally reported by E. F. Loftus and J. Pickrell (1995). Participants recalled events provided by parents on 3 separate occasions and were asked to imagine true and false unremembered events. True memories were rated by both participants and observers as more rich in recollective experience and were rated by participants as more important, more emotionally intense, as having clearer imagery, and as less typical than false memories. Rehearsal frequency was used as a covariate, eliminating these effects. Imagery in true memories was most often viewed from the field perspective, whereas imagery in false memories was most often viewed from the observer perspective. More information was communicated in true memories, and true memories contained more information concerning the consequences of described events. Results suggest repeated remembering can make false memories more rich in recollective experience and more like true memories. Differences between true and false memories suggest some potentially distinct characteristics of false memories and provide insight into the process of false memory creation.     

The recollective experience of cross-modality confusion errors

There are at least two qualitatively different types of subjective experience that can accompany accurate recognition memory. Sometimes recognition is accompanied by conscious recollection of the learning episode (i.e., it isremembered), and in other cases it is not (i.e., it is simplyknown that the item is old). In the present study, we assessed the subjective experience that accompanies crossmodality confusion errors (misidentifying words as pictures) by measuring the extent to which subjects claimed toremember versusknow that the item was presented as a picture. The results of two experiments demonstrate that cross-modality confusion errors are often accompanied by conscious recollection, although not to the same extent as accurate memories. The findings also show that there is considerable overlap in the recollective experience that accompanies accurate and erroneous memories. Finally, the results support the contention that recollective experience cannot be directly inferred from test performance.     

Sex differences in recollective experience for olfactory and verbal information

We examined recollective experience as a function of sex for olfactory and verbal information. In the first study, men and women studied a set of highly familiar odors with incidental or intentional encoding instructions. In the second study, participants were presented with a number of sentences. At recognition, participants indicated whether their positive response was based on conscious recollection (remembering), a feeling of familiarity (knowing), or guessing. The results indicated that recollection was higher among women than men, and that familiarity-based recognition was equally large across sex for both types of information.The finding that the sex-related experiential difference disappeared when controlling for verbal proficiency suggests that sex-related differences in activating verbal information play an important role for sex differences in recollective experience.