A jigsaw puzzle theory of memory

The principal novel feature of this paper is the notion that a coherent memory can be synthesised from a set of partially coherent memory fragments by maximising a particular function, Harmony (Smolensky, 1986). The appeal of Harmony is that it fulfils two functions: it is at the heart of the synthesis algorithm and it provides a natural measure for "feeling-of-knowing". The model is applied to feeling-of-knowing data, flashbulb memories, flashbacks, repression, dissociation, memory stability across repeated recalls, and the effects of cue size on retrieval.     

Measures of feeling-of-knowing accuracy: A new look at an old problem

Two ordinal measures of feeling-of-knowing performance appropriate for n × n data arrays are reviewed. Goodman and Kruskal's gamma provides a measure of association between recognition performance and feeling-of-knowing judgements. The Hamann coefficient provides a measure of agreement accuracy. The relative strengths and weaknesses of each measure are compared at length. A proof is provided, which reveals a lack of one-to-one relation between the two and suggests that they may be independent under most circumstances. It is concluded that both measures should be reported together as complementary indices as each captures a different facet of feeling-of-knowing performance. Alternative measures for gamma and the Hamann coefficient are considered and a number of recommendations are made for future research.     

Accuracy of feeling-of-knowing judgments for predicting perceptual identification and relearning

The feeding of knowing refers to predictions about subsequent memory performance on previously nonrecalled items. The most frequently investigated type of subsequent performance has been recognition. The present research explored predictive accuracy with two new feeling-of-knowing criterion tests (in addition to recognition): relearning and perceptual identification. In two experiments, people attempted to recall the answers to general-information questions such as, "What is the capital of Australia?", then made feeling-of-knowing predictions for all nonrecalled answers, and finally had a criterion test to assess the accuracy of the feeling-of-knowing predictions. Experiment 1 demonstrated that perceptual identification can be employed successfully as a criterion test for the feeling of knowing. This opens a new way for metamemory research via perception. Moreover, the feeling-of-knowing accuracy for predicting perceptual identification was not significantly correlated with the feeling-of-knowing accuracy for predicting recognition, in accord with the idea that these two tests assess memory differently. Experiment 2 demonstrated that relearning performance can also be predicted by feeling-of-knowing judgments. Both experiments showed that there is a positive relationship between the feeling of knowing and the amount of time elapsing before a memory search is terminated during recall. Further analyses showed that this relationship is substantial for nonrecalled items for which the person did not guess an answer (omission errors), but the relationship is null or negative for nonrecalled items that the person guessed incorrectly (commission errors). Several theoretical mechanisms that may underlie the feeling of knowing are proposed.     

Caffeine cravings impair memory and metacognition

Cravings for food and other substances can impair cognition. We extended previous research by testing the effects of caffeine cravings on cued-recall and recognition memory tasks, and on the accuracy of judgements of learning (JOLs; predicted future recall) and feeling-of-knowing (FOK; predicted future recognition for items that cannot be recalled). Participants (N?=?55) studied word pairs (POND-BOOK) and completed a cued-recall test and a recognition test. Participants made JOLs prior to the cued-recall test and FOK judgements prior to the recognition test. Participants were randomly allocated to a craving or control condition; we manipulated caffeine cravings via a combination of abstinence, cue exposure, and imagery. Cravings impaired memory performance on the cued-recall and recognition tasks. Cravings also impaired resolution (the ability to distinguish items that would be remembered from those that would not) for FOK judgements but not JOLs, and reduced calibration (correspondence between predicted and actual accuracy) for JOLs but not FOK judgements. Additional analysis of the cued-recall data suggested that cravings also reduced participants’ ability to monitor the likely accuracy of answers during the cued-recall test. These findings add to prior research demonstrating that memory strength manipulations have systematically different effects on different types of metacognitive judgements.     

Two dissociable aspects of feeling-of-knowing: Knowing that you know and knowing that you do not know

Feeling-of-knowing judgement is traditionally regarded as a unitary cognitive process. However, recent research suggests that knowing that you know (positive feeling-of-knowing) and knowing that you do not know (negative feeling-of-knowing) have different neural substrates (Luo, Niki, Ying, & Luo, 2004 Luo, J., Niki, K., Ying, X. P. and Luo, Y. J. 2004. Knowing that you know and knowing that you don't know: A fMRI study on feeling of knowing (FOK). Acta Psychologica Sinica, 36: 426–443.  [Google Scholar]). In the present study, we used a paradigm adapted from Koriat and Levy-Sadot (2001) Koriat, A. and Levy-Sadot, R. 2001. The combined contributions of the cue-familiarity and accessibility heuristics to feelings of knowing. Journal of Experimental Psychology: Learning, Memory, and Cognition, 27: 34–53. [Crossref], [PubMed], [Web of Science ®] , [Google Scholar] to examine whether positive feeling-of-knowing and negative feeling-of-knowing were mediated by distinct cognitive processes. We found that positive and negative feeling-of-knowing were dissociated during immediate feeling-of-knowing judgements (i.e., preliminary feeling-of-knowing) and delayed feeling-of-knowing judgements (i.e., postretrieval feeling-of-knowing). At the judgement intervals, positive feeling-of-knowing was based on partial recovery of the nonrecalled targets, whereas negative feeling-of-knowing was determined by familiarity with the retrieval cues. Our results suggest that feeling-of-knowing is a heterogeneous process.     

A comparison of three predictors of an individual's memory performance: the individual's feeling of knowing versus the normative feeling of knowing versus base-rate item difficulty

Distinctions are drawn between different predictors of an individual's memory performance, with emphasis on the notion of privileged access to idiosyncratic knowledge. Research is reported in which undergraduates attempted to recall the answers to general-information questions, then made feeling-of-knowing judgments on nonrecalled items, and subsequently had a criterion test (relearning, perceptual identification, or one of two versions of recognition). For predicting an individual's criterion performance, the individual's own feeling-of-knowing predictions were intermediate between two kinds of normative predictions: The individual's feeling-of-knowing predictions were more accurate than predictions derived from normative feeling-of-knowing ratings but were less accurate than predictions derived from base-rate item difficulty (normative probabilities of correct recall). Subsidiary analyses showed that factors other than unreliability are responsible for the partial inaccuracy of the individual's feeling of knowing. Ramifications are discussed for possible ways to improve the accuracy of an individual's feeling-of-knowing predictions.     

Accuracy and stability of metacognitive monitoring: A new measure

An examination of gamma (?; Goodman & Kruskal, 1954) and the Hamann coefficient (HC; see Schraw, 1995) as a measure of feeling-of-knowing (FOK) accuracy in the prediction of subsequent memory performance shows that neither coefficient provides a pure measure of accuracy in 2 (feeling-of-not-knowing and FOK) × 2 (correct and incorrect recognition) cases. γ underestimated accuracy in the m × 2 case with m being an integer larger than 2, producing low and unstable values of γ. In the present study, FOK predictive accuracy is treated as the extent to which the percentage of correct recognition can be increased by an increase from one FOK rank to another. A statistic computing the relative magnitude of the percentage increase to its maximal increase, designated as C, is able to provide a correct estimate of accuracy. Furthermore, the value of C is stable across different portions of FOK data and is free from restricted-/truncated-range and fineness/ coarseness effects.     

The relation between feelings of knowing and the number of neighboring concepts linked to the test cue

We investigated whether feeling-of-knowing judgments are influenced by the number of different neighboring concepts linked to the test cue in long-term memory as measured using association norms. The purpose was to evaluate contrasting predictions made by the partial-retrieval hypothesis and the competition hypothesis. The partial-retrieval hypothesis assumes the more neighboring concepts activated by the test cue, the higher the feeling of knowing. In contrast, the competition hypothesis assumes that feelings of knowing are sensitive to competition between neighboring concepts, and it predicts that the fewer neighboring concepts activated by the cue, the higher the feeling of knowing. The findings were compatible with the competition hypothesis showing that both feeling-of-knowing and prediction-of-knowing ratings always were higher, the fewer different concepts were linked to the test cue. We obtained an identical pattern of results using different kinds of cues including taxonomic category names, ending sounds, and meaningfully related associates. We consider different ways that these findings could be reconciled with the partial-retrieval hypothesis, and we also discuss implications for other explanations of feeling-of-knowing effects.     

Memory and metamemory: a study of the feeling-of-knowing phenomenon in amnesic patients

Accuracy of the feeling of knowing was tested in patients with Korsakoff's syndrome, patients prescribed electroconvulsive therapy, four other cases of amnesia, and control subjects. In Experiment 1, we tested feeling-of-knowing accuracy for the answers to general information questions that could not be recalled. Subjects were asked to rank nonrecalled questions in terms of how likely they thought they would be able to recognize the answers and were then given a recognition test for these items. Only patients with Korsakoff's syndrome were impaired in making feeling-of-knowing predictions. The other amnesic patients were as accurate as control subjects in their feeling-of-knowing predictions. In Experiment 2, we replicated these findings in a sentence memory paradigm that tested newly learned information. The results showed that impaired metamemory is not an obligatory feature of amnesia, because amnesia can occur without detectable metamemory deficits. The impaired metamemory exhibited by patients with Korsakoff's syndrome reflects a cognitive impairment that is not typically observed in other forms of amnesia.     

Two dissociable aspects of feeling-of-knowing: knowing that you know and knowing that you do not know

Feeling-of-knowing judgement is traditionally regarded as a unitary cognitive process. However, recent research suggests that knowing that you know (positive feeling-of-knowing) and knowing that you do not know (negative feeling-of-knowing) have different neural substrates (Luo, Niki, Ying, & Luo, 2004). In the present study, we used a paradigm adapted from Koriat and Levy-Sadot (2001) to examine whether positive feeling-of-knowing and negative feeling-of-knowing were mediated by distinct cognitive processes. We found that positive and negative feeling-of-knowing were dissociated during immediate feeling-of-knowing judgements (i.e., preliminary feeling-of-knowing) and delayed feeling-of-knowing judgements (i.e., postretrieval feeling-of-knowing). At the judgement intervals, positive feeling-of-knowing was based on partial recovery of the nonrecalled targets, whereas negative feeling-of-knowing was determined by familiarity with the retrieval cues. Our results suggest that feeling-of-knowing is a heterogeneous process.     

Immediate judgments of learning are insensitive to implicit interference effects at retrieval

We conducted three experiments to determine whether metamemory predictions at encoding, immediate judgments of learning (IJOLs) are sensitive to implicit interference effects that will occur at retrieval. Implicit interference was manipulated by varying the association set size of the cue (Experiments 1 and 2) or the target (Experiment 3). The typical finding is that memory is worse for large-set-size cues and targets, but only when the target is studied alone and later prompted with a related cue (extralist). When the pairs are studied together (intralist), recall is the same regardless of set size; set size effects are eliminated. Metamemory predictions at retrieval, such as delayed JOLs (DJOLs) and feeling-of-knowing (FOK) judgments accurately reflect implicit interference effects (e.g., Eakin & Hertzog, 2006. In all three experiments, we found that DJOLs and FOKs accurately predicted set size effects on retrieval but that IJOLs did not. The findings provide further evidence that metamemory predictions are inferred from information other than direct access to the state of the memory trace, as well as indicate that inferences are based on different sources depending on when in the memory process predictions are made.     

Familiarity supports associative recognition memory for face stimuli that can be unitised: Evidence from receiver operating characteristics

According to dual-process models, associative recognition memory mainly relies on recollection without benefiting from familiarity. This study investigates the circumstances under which familiarity may support associative recognition judgements by comparing recognition memory for arbitrarily paired items (i.e., pairs of face stimuli depicting two different persons; interitem associations) with recognition memory for pairs of items that are highly overlapping and can be unitised into a coherent whole (i.e., pairs of physically different but very similar face stimuli depicting the same person; intraitem associations). Estimates of familiarity and recollection were derived from receiver operating characteristics. Consistent with the hypothesis that familiarity is able to support associative recognition memory, but only when the to-be-associated stimuli can be unitised, results from two experiments revealed higher familiarity estimates for intra- compared to interitem associations. By contrast, recollection for recombined pairs was higher for inter- compared to intraitem associations. We propose a hypothetical model on how intraitem associations may benefit from familiarity.     

Memory and metamemory in obsessive-compulsive disorder

Studies on the link between checking and memory problems have produced equivocal results regarding a general memory deficit in patients with obsessive-compulsive disorder and subclinical checkers. However, there is clear and consistent evidence that patients with obsessive-compulsive disorder (OCD) show lack of confidence in their memory performance. The purpose of the present study was to investigate memory and metamemory performance (feeling-of-knowing judgments) for neutral and threat-related material in three groups: OCD patients (OCs), subclinical checkers (SCs), and normal controls (NCs). Participants studied a list of neutral and threat word pairs. After an initial cued-recall test, they provided feeling-of-knowing (FOK) judgments for unrecalled word pairs, followed by a recognition test. The results showed that OCs but not SCs were impaired in both recall and recognition compared to NCs. OCs were also less confident about their future memory performance than the other two groups, as reflected in their lower FOK ratings. Moreover, FOK judgments of the OCs were not reliable predictors of their recognition performance. Finally, neither OCs nor SCs showed any evidence of memory bias for threat-relevant information. The results support the idea of a general memory and a metamemory deficit in OCs.     

Effects of alcohol intoxication on metamemory and on retrieval from long-term memory

In a balanced-placebo design, people expected either an alcohol drink or placebo drink and consumed either alcohol (1 ml/kg) or placebo. Shortly thereafter, each person attempted to recall the answers to general-information questions (e.g., "What is the capital of Chile?"), made confidence judgments about the accuracy of recall, made feeling-of-knowing judgments on all nonrecalled items, and received a recognition test. Unanticipated outcomes included: Alcohol intoxication significantly hindered recall from long-term memory, contrary to previous conclusions that alcohol does not affect retrieval; people's expectancy of alcohol had no significant effect on memory or metamemory performance, contrary to its established effects on other kinds of performance; and alcohol intoxication produced no significant overconfidence in judgments about recall or in feeling-of-knowing judgments, contrary to the overconfidence produced in other kinds of judgments such as an intoxicated person's assessment of his driving ability. This last outcome implies that alcohol intoxication does not produce a general lowering of the threshold for confidence but rather has effects that are situation specific.     

The impact of depression and PTSD symptom severity on trauma memory

Posttraumatic stress disorder (PTSD) and depression frequently co-occur following a traumatic event. Differences in the processing of autobiographical memory have been observed in both disorders in the form of overgeneralised memories and negative intrusive memories. The current study examined how symptoms of PTSD and depression influence the phenomenological characteristics of trauma memories. Undergraduate students who had experienced a traumatic event (n?=?696) completed questionnaires online including measures of PTSD and depressive symptom severity. They rated their trauma memory on several phenomenological characteristics using the Memory Experiences Questionnaire [Sutin, A. R., &; Robins, R. W. (2007). Phenomenology of autobiographical memories: The memory experiences questionnaire. Memory.]. Moderated multiple regression was used to examine how PTSD and depressive symptom severity related to each phenomenological characteristic. Symptoms of PTSD and depression were related separately and uniquely to the phenomenological characteristics of the trauma memory. PTSD severity predicted trauma memories that were more negative, contained higher sensory detail, and were more vivid. In contrast, depressive symptom severity predicted trauma memories that were less accessible and less coherent. These findings suggest that depressive and PTSD symptomatology affect traumatic memory differently and support a distinction between these two disorders.     

Characteristics of memories for traumatic and nontraumatic birth

Evidence for memory characteristic differences between trauma and other memories in non‐clinical samples is inconsistent. However, trauma is frequently confounded with the event recalled. This study compares trauma and nontrauma memories for the same event, childbirth, in a non‐clinical sample of 285 women 4–6 weeks after birth. None of the women met diagnostic criteria for post‐traumatic stress disorder. Traumatic birth, defined by the DSM‐5 event criterion, was reported by 100 women. The ratings of some memory characteristics did not differ between memories for traumatic and nontraumatic birth: All were rated highly coherent and central to women's lives, with moderate sensory memory. However, women who experienced traumatic births reported more involuntary recall, reliving, and negative/mixed emotions. Thus, trauma memories differed from nontrauma memories. In this non‐clinical sample, this is likely to be due to encoding during trauma rather than the distinctive memory profile for memories retrieved by those experiencing trauma symptoms.     

The formation of novel social category conjunctions in working memory: A possible role for the episodic buffer?

Recent research (e.g., Hutter, Crisp, Humphreys, Waters, &; Moffit; Siebler) has confirmed that combining novel social categories involves two stages (e.g., Hampton; Hastie, Schroeder, &; Weber). Furthermore, it is also evident that following stage 1 (constituent additivity), the second stage in these models involves cognitively effortful complex reasoning. However, while current theory and research has addressed how category conjunctions are initially represented to some degree, it is not clear precisely where we first combine or bind existing social constituent categories. For example, how and where do we compose and temporarily store a coherent representation of an individual who shares membership of “female” and “blacksmith” categories? In this article, we consider how the revised multi-component model of working memory (Baddeley) can assist in resolving the representational limitations in the extant two-stage theoretical models. This is a new approach to understanding how novel conjunctions form new bound “composite” representations.     

Leibniz on Memory and Consciousness

In this article, I develop a higher-order interpretation of Leibniz's theory of consciousness according to which memory is constitutive of consciousness. I offer an account of Leibniz's theory of memory on which his theory of consciousness may be based, and I then show that Leibniz could have developed a coherent higher-order account. However, it is not clear whether Leibniz held (or should have held) such an account of consciousness; I sketch an alternative that has at least as many advantages as the higher-order theory. This analysis provides an important antecedent to the contemporary discussions of higher-order theories of consciousness.     

Pupillometric assessment of retrieval operations in factual long-term memory

The process involved in recall from long-term memory were studied through the use of a general knowledge questionnaire and the technique of pupillometry. Degree of processing of the components of the retrieval process was inferred from second-by-second monitoring of pupil size. Measurements were recorded during subjects' attempts to retrieve the answer to the query, or if unsuccessful, from clues of the target (first and last letters), and if still unsuccessful, to recognize the presented target word as being associated with the question (the “Of course”, or “That's it!” experience). Pupil size differed according to the nature of the three task demands. Additionally, there were differences based on the type of outcome within the question trial (e.g., between target known but blocked — feeling-of-knowing/tip-of-tongue — and target not known), and the answer trial (recognize vs not recognize the question—answer relationship). The results were related to the search and decisional processes of retrieval.