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.     

Remembering and knowing: Two means of access to the personal past

The nature of recollective experience was examined in a recognition memory task. Subjects gave “remember” judgments to recognized items that were accompanied by conscious recollection and “know” judgments to items that were recognized on some other basis. Although a levels-of-processing effect (Experiment 1) and a picture-superiority effect (Experiment 2) were obtained for overall recognition, these effects occurred only for “remember” judgments, and were reversed for “know” judgments. In Experiment 3, targets and lures were either preceded by a masked repetition of their own presentation (thought to increase perceptual fluency) or of an unrelated word. The effect of perceptual fluency was obtained for overall recogrntion and “know” judgments but not for “remember” judgments. The data obtained for confidencejudgments using the same design (Experiment4) indicated that “remember”/”know” judgments are not made solely on the basis of confidence. These data support the two-factor theories of recognition memory by dissociating two forms of recognition, and shed light on the nature of conscious recollection.     

Reinstating effortful encoding operations at test enhances episodic remembering

Two experiments investigated the effects of reinstating encoding operations on remember and know responses in recognition memory. Experiment 1 showed that reinstating an effortful encoding task (generating words from fragments) increased remember responses at test but reinstating an automatic encoding task (reading intact words) did not. This pattern was confirmed in Experiment 2 in which words were either read intact or generated from anagrams. These findings show that repeating effortful (but not automatic) encoding operations at test cues not only the recognition of the information that was acquired via those operations but also the conscious recollection of the encoding episode.     

Reinstating effortful encoding operations at test enhances episodic remembering

Two experiments investigated the effects of reinstating encoding operations on remember and know responses in recognition memory. Experiment 1 showed that reinstating an effortful encoding task (generating words from fragments) increased remember responses at test but reinstating an automatic encoding task (reading intact words) did not. This pattern was confirmed in Experiment 2 in which words were either read intact or generated from anagrams. These findings show that repeating effortful (but not automatic) encoding operations at test cues not only the recognition of the information that was acquired via those operations but also the conscious recollection of the encoding episode.     

Effects of exact and category repetition in true and false recognition memory

Two experiments used the distinction between remembering and knowing to investigate the effects of exact and category repetition in recognition memory. In Experiment 1, exact repetition enhanced remember responses but had no reliable effect on know responses. In Experiment 2, category repetition enhanced correct know responses but had no effect on correct remember responses. Category repetition also increased false positive remember and know responses. It is argued that exact repetition influences the recollection component of recognition memory via the creation of multiple episodic traces, each of which is potentially capable of supporting a remember response, whereas category repetition influences the familiarity component of recognition memory by enhancing the fluency with which test items are processed.     

Measuring the speed of the conscious components of recognition memory: remembering is faster than knowing

Three experiments investigated response times (RTs) for remember and know responses in recognition memory. RTs to remember responses were faster than RTs to know responses, regardless of whether the remember-know decision was preceded by an old/new decision (two-step procedure) or was made without a preceding old/new decision (one-step procedure). The finding of faster RTs for R responses was also found when remember-know decisions were made retrospectively. These findings are inconsistent with dual-process models of recognition memory, which predict that recollection is slower and more effortful than familiarity. Word frequency did not influence RTs, but remember responses were faster for words than for nonwords. We argue that the difference in RTs to remember and know responses reflects the time taken to make old/new decisions on the basis of the type of information activated at test.     

Recognition memory for pictorial material in subclinical depression

Depression has been associated with impaired recollection of episodic details in tests of recognition memory that use verbal material. In two experiments, the remember/know procedure was employed to investigate the effects of dysphoric mood on recognition memory for pictorial materials that may not be subject to the same processing limitations found for verbal materials in depression. In Experiment 1, where the recognition test took place two weeks after encoding, subclinically depressed participants reported fewer know judgements which were likely to be at least partly due to a remember-to-know shift. Although pictures were accompanied by negative or neutral captions at encoding, no effect of captions on recognition memory was observed. In Experiment 2, where the recognition test occurred soon after viewing the pictures, subclinically depressed participants reported fewer remember judgements. All participants reported more remember judgements for pictures of emotionally negative content than pictures of neutral content. Together, these findings demonstrate that recognition memory for pictorial stimuli is compromised in dysphoric individuals in a way that is consistent with a recollection deficit for episodic detail and also reminiscent of that previously reported for verbal materials. These findings contribute to our developing understanding of how mood and memory interact.     

Familiarity and recollection in item and associative recognition

Recognition memory for item information (single words) and associative information (word pairs) was tested immediately and after retention intervals of 30 min and 1 day (Experiment 1) and 2 days and 7 days (Experiment 2) using Tulving's (1985) remember/know response procedure. Associative recognition decisions were accompanied by more "remember" responses and less "know" responses than item recognition decisions. Overall recognition performance and the proportion of remember responses declined at similar rates for item and associative information. The pattern of results for item recognition was consistent with Donaldson's (1996) single-factor signal detection model of remember/know responses, as comparisons based on A' between overall item recognition and remember item recognition showed no significant differences. For associative recognition, however, A' for remember responses was reliably greater than for overall recognition. The results show that recollection plays a significant role in associative recognition.     

The difference between implicit and explicit associative processes at study in creating false memory in the DRM paradigm

The effects of implicit and explicit associative processes for false recognition were examined by manipulating exposure duration of studied items; 20 ms or 2000 ms. Participants studied lists of words that were high associates to a nonpresented word (critical lure) in either condition. After learning each list, they took a recognition test and remember/know judgements immediately (Experiment 1) or 1 minute later (Experiment 2). In Experiment 1, know responses for critical lures were more in the 20 ms than in the 2000 ms conditions, while remember responses for them were more in the 2000 ms condition. Implicit associative processes create familiarity of critical lures, and explicit associative processes create details of false memories. Comparing the results of Experiment 1 with those of Experiment 2, remember responses for critical lures were increased with the prolonged time only in the 20 ms condition. Characteristics of false memory made by implicit associative processes could be changed by prolonged time.     

The difference between implicit and explicit associative processes at study in creating false memory in the DRM paradigm

The effects of implicit and explicit associative processes for false recognition were examined by manipulating exposure duration of studied items; 20 ms or 2000 ms. Participants studied lists of words that were high associates to a nonpresented word (critical lure) in either condition. After learning each list, they took a recognition test and remember/know judgements immediately (Experiment 1) or 1 minute later (Experiment 2). In Experiment 1, know responses for critical lures were more in the 20 ms than in the 2000 ms conditions, while remember responses for them were more in the 2000 ms condition. Implicit associative processes create familiarity of critical lures, and explicit associative processes create details of false memories. Comparing the results of Experiment 1 with those of Experiment 2, remember responses for critical lures were increased with the prolonged time only in the 20 ms condition. Characteristics of false memory made by implicit associative processes could be changed by prolonged time.     

Dissociating familiarity from recollection using rote rehearsal

Recollection-based recognition memory judgments benefit greatly from effortful elaborative encoding, whereas familiarity-based judgments are much less sensitive to such manipulations. In this study, we have examined whether rote rehearsal under divided attention might produce the opposite dissociation, benefiting familiarity more than recollection. Subjects rehearsed word pairs during the "distractor" phase of a working memory span task, and were then given a surprise memory test for the distractor items at the end of the experiment. Experiment 1 demonstrated that increasing rehearsal elevated the recognition rate for intact and rearranged pairs, but neither associative recognition accuracy nor implicit fragment completion benefited from rehearsal. The results suggest that rote rehearsal leads to a greater increase in familiarity than in recollection, and that the increase in observed familiarity cannot be attributed to effects of repetition priming. In Experiment 2, we tested item recognition with the remember/know procedure, and the results supported the conclusions of Experiment 1. Moreover, a signal detection model of remember/know performance systematically overpredicted rehearsal increases in remember rates, and this worsened when high-rehearsal items were assumed to be more variable in strength. The results suggest that rote rehearsal can dissociate familiarity from recollection at the time of encoding and that item recognition cannot be fully accommodated within a one-dimensional signal detection model.     

Investigating the attentional demands of recognition memory: Manipulating depth of encoding at study and level of attention at test

Two experiments investigated the effects of divided attention at test after manipulating levels of processing at study. In Experiment 1 items were studied either intact or as anagrams. In Experiment 2 items were studied with either full or divided attention (DA). In both experiments participants carried out a recognition test with either full or divided attention. Analysis of remember and know responses revealed that DA at test had no effect on remember responses to anagrams or to items studied with full attention. In contrast, Know responses decreased with DA at test, and this occurred for items studied in both deep and shallow encoding conditions. The present study confirms recent findings (Knott & Dewhurst, 2007a) that knowing can rely on more controlled retrieval processes, whereas remembering can rely on more automatic retrieval processes. Differences in the controlled processes associated with recollection and familiarity and remember and know responses are discussed.     

Remembering parts and wholes: Configural processing in face recollection

In two experiments, we examined the role of configural processing on states of awareness in face recognition. Configural processing was manipulated by presenting upright and inverted faces during study and test. After studying facial photographs of humans (Experiment 1) and horses (Experiment 2), participants provided a remember/know judgement for each recognised test face. In both experiments, disrupted configural processing had selective effects on states of awareness, so that inversion reduced remember, but not know, responses. Experiment 2 revealed disproportionate inversion effects in that the difference in remember responses between upright and inverted items was significant for human faces but not horses. These findings suggest that configural processing facilitates explicit recollection by providing a distinctive combination of nonsalient event attributes.     

Illusions of familiarity caused by cohort activation

Subjects took part in an auditory lexical decision task followed by an auditory test of recognition memory for words presented in this task. Subjects categorized their recognition judgments as based on either recollection (“remember” responses) or familiarity (“know” responses). Distractor items in the recognition test included the base words from which the nonwords used in the lexical decision task were derived. Consistent with the findings of Wallace, Stewart, Sherman, and Mellor (1995), more false alarms were made to “late” base words (where the corresponding nonwords were created by changing a phoneme near the end of the word) than to “early” base words (corresponding nonwords were created by changing a phoneme at the beginning of the word). However, this effect was found in “know” responses but not in “remember” responses. The findings are attributed to enhanced fluency with which the base words are processed following their implicit activation at encoding.     

Recognition memory for valenced and arousing materials under conditions of divided attention

Two experiments are reported that examined the effect of both valence and arousal on recognition memory performance. Each experiment used two classes of negative items that differed in arousal, as well as a neutral and non-arousing set of items. In Experiment 1 a difficult divided attention task was crossed with the learning and test phases of the experiment. In Experiment 2 encoding time was manipulated and remember–know judgements were collected. The emotional enhancement effect often found with verbal materials survived the depletion of cognitive resources, as did the extra benefit accruing from high arousal. Although we found that arousal led to more recollection, the general conclusion that we draw is that the effect of emotion on recognition memory can be attributed to relatively automatic influences.     

Remembering is in the details: effects of test-list context on memory for an event

We examined how recognition judgements for a set of event details are influenced by the relative difficulty of the other details included on the test. Participants viewed a crime event and then assigned remember/know judgements to details on a recognition test. In Experiment 1, details of medium difficulty were more likely to be classified as remembered when mixed with hard details rather than easy details. Similarly, in Experiment 2, medium details presented in blocked format were more likely to be classified as remembered when preceded by a block of hard details rather than a block of easy details.The test-list context thus appears to influence how participants define remembering. In Experiment 3, informing participants of the relative difficulty of the upcoming block of details eliminated the blocking effect. Implications for accounts of remember/know judgements and for conducting memory interviews are discussed.     

Remembering is in the details: Effects of test-list context on memory for an event

We examined how recognition judgements for a set of event details are influenced by the relative difficulty of the other details included on the test. Participants viewed a crime event and then assigned remember/know judgements to details on a recognition test. In Experiment 1, details of medium difficulty were more likely to be classified as remembered when mixed with hard details rather than easy details. Similarly, in Experiment 2, medium details presented in blocked format were more likely to be classified as remembered when preceded by a block of hard details rather than a block of easy details. The test-list context thus appears to influence how participants define remembering. In Experiment 3, informing participants of the relative difficulty of the upcoming block of details eliminated the blocking effect. Implications for accounts of remember/know judgements and for conducting memory interviews are discussed.     

Context effects on remembering and knowing: the expectancy heuristic

Three experiments are reported examining the effect of context on remember-know judgments. In Experiments 1 and 2, medium-frequency words were intermixed with high-frequency or low-frequency words at study or at test, respectively. Remember responses were greater for medium-frequency targets when they were studied or tested among high-frequency, as compared with low-frequency, words. The authors proposed a decision-based mechanism called "the expectancy heuristic" to explain why remember responses were more likely when items were studied or tested in the context of words that were relatively less distinct. According to the expectancy heuristic, when items on a recognition test exceed an expected level of memorability they will be given a remember judgment but when they do not, but are still more familiar than new words, they will be given a know judgment. Experiment 3, which varied expectancies about the strength of tested targets, demonstrated the use of the expectancy heuristic, indicating that it operates by selectively influencing the remember criterion rather than by influencing recollection of studied items.     

Recollective experience in the revelation effect: Separating the contributions of recollection and familiarity

The revelation effect is a phenomenon of recognition memory in which words presented for a recognition decision are more likely to be identified as previously studied if they are initially disguised and are then somehow revealed to the subject. The goal of the present experiments was to determine whether the revelation effect has similar or different influences on the conscious recollection of a previous encounter with a test item and on the feeling of familiarity evoked by a test item. The process-dissociation procedure (Experiment 1) and the remember/know procedure (Experiment 2) were used to achieve this goal. The main findings of these experiments were that revealing an item at test (1) increased the feeling of familiarity associated with that item, especially if it was not previously studied, and (2) decreased conscious recollection of previously studied items. These data narrow the range of potential explanations of the revelation effect.     

The retrieval practice effect in associative recognition

Recalling an item interferes with recall of related memories. Evidence is presented that retrieval interference occurs in associative recognition as well as recall. In Experiment 1, subjects studied pairs of category exemplars. Retrieval practice followed, during which some pairs appeared in a cued recall test. A final test of associative recognition (with remember-know judgments) found lower accuracy and hit rate for nonpracticed pairs belonging to retrieval-practiced categories. In Experiment 2, subjects studied noun pairs from overlapping sets, with study duration manipulated between subjects. Retrieval practice was manipulated by presenting some members of a set in a previous block during the recognition test. With long study duration, retrieval interference was evident in both recognition and remember judgments. With short study duration, it appeared only in remember judgments. These results support a dual-process account in which retrieval interference is specific to recollection and becomes evident in recognition performance only when recollection is sufficiently dominant.