Reply to Farrell and Lewandowsky: Recency—contiguity interactions predicted by the temporal context model

Farrell and Lewandowsky (2008) argued that the temporal context model (TCM; Howard & Kahana, 2002) cannot explain nonmonotonicities in the contiguity effect seen at extreme lags. However, TCM actually predicts these nonmonotonicities to the extent that end-of-list context persists as a retrieval cue during recall and to the extent that end-of-list context generates a recency effect. We show that the observed nonmonotonicity in the contiguity effect interacts with the recency effect, as predicted by TCM. In conditions, such as immediate and continualdistractor free recall, that exhibit strong recency, one observes more prominent nonmonotonicities in the contiguity effect than in conditions, such as delayed free recall, that attenuate recency. The nonmonotonicities in the contiguity effect at extreme lags, and the interactions between recency and contiguity, result from the role of end-of-list context as a retrieval cue in TCM. Results of an additional simulation based on the Howard and Kahana (2002) version of TCM may be downloaded from http://pbr.psychonomic-journals.org/content/supplemental.     

The conditional-recency dissociation is confounded with nominal recency: Should unitary models of memory still be devaluated?

The conditional-recency dissociation between immediate and delayed free recall FR; Farrell (Journal of Experimental Psychology: Learning, Memory, and Cognition, 36, 324–347, 2010) has critical implications regarding the prolonged debate between unitary and dual-store models of memory. In immediate FR, when the availability of items is controlled for, the recency of the final list item increases across the first few output positions. No such increase is found in delayed FR, with a trend in the opposite direction. This dissociation challenges temporal context TCM; Howard & Kahana (Journal of Mathematical Psychology, 46, 269–299, 2002) and distinctiveness SIMPLE; Brown, Neath, & Chater (Psychological Review, 114, 539–576, 2007) unitary models of memory and suggests the involvement of a short-term buffer in immediate FR. We show that this dissociation is confounded with the different magnitudes of nominal recency (i.e., the prevalence of the final list item) found in immediate as compared to delayed FR. By reshuffling output orders and comparing the empirical results to those of a null hypothesis of no output-order effect, we controlled for the greater prevalence of the final list item that has been observed in immediate FR. Under this control, we found no evidence for a dissociation in the tendency to recall the final list item across output positions. This finding suggests that the conditional-recency dissociation imposes no new constraint on unitary models of memory. More generally, we demonstrate how biases that influence measures of output-order tendencies (e.g., conditional recency) can be controlled for, thus yielding “purer” measures of these variables.     

Associative processes in immediate recency

Some theorists have argued that the immediate recency effect observed in free recall reflects the emptying out of the contents of a short-term memory buffer (Davelaar, Goshen-Gottstein, Ashkenazi, Haarmann, & Usher, 2005). Others have argued that immediate recency reflects the properties of temporal context used to cue free recall (Howard & Kahana, 2002). We examined immediate free recall of lists with an item from the middle of the list repeated at or near the end. If associative processes contribute to immediate recency, as predicted by the temporal context account, the neighbors of the initial presentation of the repeated item should show enhanced recall at the initial stages of immediate recall. Recall transitions early in output--and even the initiation of recall itself-showed evidence for temporally defined associations that resemble those observed in recall from long-term memory. These results have strong implications for models of the immediate recency effect in free recall.     

Age dissociates recency and lag recency effects in free recall

The temporal relations among word-list items exert a powerful influence on episodic memory retrieval. Two experiments were conducted with younger and older adults in which the age-related recall deficit was examined by using a decomposition method to the serial position curve, partitioning performance into (a) the probability of first recall, illustrating the recency effect, and (b) the conditional response probability, illustrating the lag recency effect (M. W. Howard & M. J. Kahana, 1999). Although the older adults initiated recall in the same manner in both immediate and delayed free recall, temporal proximity of study items (contiguity) exerted a much weaker influence on recall transitions in older adults. This finding suggests that an associative deficit may be an important contributor to older adults' well-known impairment in free recall.     

Evidence for similar principles in episodic and semantic memory: The presidential serial position function

When people recall a list of items that they have just experienced (an episodic memory task), the resulting serial position function looks strikingly similar to that observed when people are asked to recall the presidents of the United States (a semantic memory task). Despite the similarity in appearance, there is disagreement about whether the two functions arise from the same processes. A local distinctiveness model of memory, SIMPLE, successfully fit the presidential data using two underlying dimensions: one corresponding to item (or presidential) distinctiveness and the other to order (or positional) distinctiveness. According to the model, presidential primacy and recency are due to the same mechanisms that give rise to primacy and recency effects in both shortand long-term episodic memory. All of these primacy and recency effects reflect the relative distinctiveness principle (Surprenant & Neath, 2009): Items will be well remembered to the extent that they are more distinct than competing items at the time of retrieval.     

Pauses and durations exhibit a serial position effect

This article reports evidence of two kinds of serial position effects in immediate serial recall: One involves interresponse pauses, and the other response durations. In forward and backward recall, responding was faster at initial and final positions than at center positions, exhibiting a bow-shaped function relative to serial position. These data were obtained in a spoken recall study in which ungrouped lists of four to six words and postcuing of recall direction were used. The pause pattern is consistent with several models of serial memory, including a distinctiveness model (Brown, Neath, & Chater, 2002) and a version of the ACT—R model augmented with a spontaneous grouping strategy (Maybery, Parmentier, & Jones, 2002). The duration pattern suggests that response articulation depends on the processing context, rather than being modular.     

Issues with the SIMPLE model: comment on Brown, Neath, and Chater (2007)

SIMPLE (G. D. A. Brown, I. Neath, & N. Chater, 2007) attempts to explain data from serial recall and free recall in the same theoretical framework. While it can fit the free-recall serial-position curves that are the cornerstone of the 2-store buffer model, it does not address 2 classic issues in short-term memory research: similarity effects and presentation-rate effects. Similarity effects in free recall led to important work on organization in free recall, whereas similarity effects in serial recall led to the phonological basis of short-term memory. Presentation-rate effects operate quite differently in free and serial recall. The model also does not consider recall order effects or interresponse times in free recall, which may be problematic.     

The effects of gender on the retrieval of episodic and semantic components of autobiographical memory

Despite consistent evidence that women exhibit greater episodic memory specificity than men, little attention has been paid to gender differences in the production of episodic details during autobiographical recall under conditions of high and low retrieval support. Similarly the role of gender on the production of semantic details used to support autobiographical memory recollections of specific events has been largely unexplored. In the present study an undergraduate sample of 50 men and 50 women were assessed using the Autobiographical Interview (Levine, Svoboda, Hay, Winocur, & Moscovitch, 2002). Women recalled more episodic information compared to men in the high retrieval support condition, whereas no gender differences were found in the low retrieval support condition. In addition, women produced more repetitions compared to men in the high retrieval support condition. No gender differences were found in the production of semantic details. These results are interpreted in terms of gender differences in encoding and reminiscence practices. This research adds to the literature on gender differences in memory recall and suggests that gender is an important variable in explaining individual differences in AM recall.     

The temporal context model in spatial navigation and relational learning: toward a common explanation of medial temporal lobe function across domains

The medial temporal lobe (MTL) has been studied extensively at all levels of analysis, yet its function remains unclear. Theory regarding the cognitive function of the MTL has centered along 3 themes. Different authors have emphasized the role of the MTL in episodic recall, spatial navigation, or relational memory. Starting with the temporal context model (M. W. Howard & M. J. Kahana, 2002a), a distributed memory model that has been applied to benchmark data from episodic recall tasks, the authors propose that the entorhinal cortex supports a gradually changing representation of temporal context and the hippocampus proper enables retrieval of these contextual states. Simulation studies show this hypothesis explains the firing of place cells in the entorhinal cortex and the behavioral effects of hippocampal lesion in relational memory tasks. These results constitute a first step toward a unified computational theory of MTL function that integrates neurophysiological, neuropsychological, and cognitive findings.     

Contextual variability and serial position effects in free recall.

In immediate free recall, words recalled successively tend to come from nearby serial positions. M. J. Kahana (1996) documented this effect and showed that this tendency, which the authors refer to as the lag recency effect, is well described by a variant of the search of associative memory (SAM) model (J. G. W. Raaijmakers & R. M. Shiffrin, 1980, 1981). In 2 experiments, participants performed immediate, delayed, and continuous distractor free recall under conditions designed to minimize rehearsal. The lag recency effect, previously observed in immediate free recall, was also observed in delayed and continuous distractor free recall. Although two-store memory models, such as SAM, readily account for the end-of-list recency effect in immediate free recall, and its attenuation in delayed free recall, these models fail to account for the long-term recency effect. By means of analytic simulations, the authors show that both the end of list recency effect and the lag recency effect, across all distractor conditions, can be explained by a single-store model in which context, retrieved with each recalled item, serves as a cue for subsequent recalls.     

Serial position effects in short-term visual memory: A SIMPLE explanation?

A version of Sternberg's (1966) short-term visual memory recognition paradigm with pictures of unfamiliar faces as stimuli was used in three experiments to assess the applicability of the distinctiveness-based SIMPLE model proposed by Brown, Neath, and Chater (2002). Initial simulations indicated that the amount of recency predicted increased as the parameter measuring the psychological distinctiveness of the stimulus material (c) increased and that the amount of primacy was dependent on the extent of proactive interference from previously presented stimuli. The data from Experiment 1, in which memory lists of four and five faces varying in visual similarity were used, confirmed the predicted extended recency effect. However, changes in visual similarity were not found to produce changes in c. In Experiments 2 and 3, the conditions that influence the magnitude of c were explored. These revealed that both the familiarity of the stimulus class before testing and changes in familiarity, due to perceptual learning, influenced distinctiveness, as indexed by the parameter c. Overall, the empirical data from all three experiments were well fit by SIMPLE.     

Autobiographical memory deficits in schizophrenia

This study investigated autobiographical memory processes in a group of individuals diagnosed with schizophrenia and matched controls. The schizophrenia group displayed an overgeneral style of autobiographical memory retrieval on two widely used measures, and displayed problems retrieving both autobiographical facts and events. They showed a specific impairment in the recall of autobiographical events and facts in early adulthood, around the time of onset of their illness. Retrieval deficits were independent of mood state and premorbid intellectual functioning. The magnitude of the deficits in autobiographical memory retrieval specificity were considerably greater than any general impairments in episodic and working memory.     

Rumination and overgeneral autobiographical memory

Two studies investigated the effects of rumination on the retrieval of autobiographical memories in high-depressed and low-depressed individuals. Experiment 1 administered either a rumination or distraction task prior to a cued autobiographical memory task. High-depressed participants recalled more overgeneral memories following rumination relative to distraction, whereas experimental inductions did not influence low-depressed participants. Experiment 2 administered either a positive or negative rumination task prior to a cued autobiographical memory task. Negatively valenced rumination led high-depressed participants to recall more overgeneral memories than positively valenced rumination; this effect was not observed in low-depressed participants. These findings accord with the proposal that rumination is a mediating mechanism in the retrieval of overgeneral memories, and extends this proposal by indicating that negatively valenced ruminative content is particularly instrumental in inducing overgeneral retrieval.     

A Distributed Representation of Temporal Context

The principles of recency and contiguity are two cornerstones of the theoretical and empirical analysis of human memory. Recency has been alternatively explained by mechanisms of decay, displacement, and retroactive interference. Another account of recency is based on the idea of variable context (Estes, 1955; Mensink & Raaijmakers, 1989). Such notions are typically cast in terms of a randomly fluctuating population of elements reflective of subtle changes in the environment or in the subjects' mental state. This random context view has recently been incorporated into distributed and neural network memory models (Murdock, 1997; Murdock, Smith, & Bai, 2001). Here we propose an alternative model. Rather than being driven by random fluctuations, this formulation, the temporal context model (TCM), uses retrieval of prior contextual states to drive contextual drift. In TCM, retrieved context is an inherently asymmetric retrieval cue. This allows the model to provide a principled explanation of the widespread advantage for forward recalls in free and serial recall. Modeling data from single-trial free recall, we demonstrate that TCM can simultaneously explain recency and contiguity effects across time scales.     

Empirical and theoretical limits on lag recency in free recall

One widely accepted empirical regularity in free recall holds that when people successively transition from report of one list item to another, they prefer transitions across short lags (e.g., by reporting items from adjacent serial positions) to transitions involving large lags. This regularity has provided crucial support for the temporal context model (TCM), a model of the evolution of temporal context in episodic memory (Howard & Kahana, 2002a). We report a reanalysis of 14 data sets that shows that, contrary to the presumed preference for short lags, people often produce transitions with larger lags during recall. We show that these data cannot be accommodated by the TCM. We furthermore show that existing applications of the model have, for mathematical convenience, introduced assumptions that have circumvented its core principle of context evolution. When we instantiated the TCM as it was actually described, with a gradually evolving context, we found that its behavior qualitatively departed from that of the version currently implemented, but that the model was still unable to capture the nature of transitions in free recall. We conclude that the TCM requires further modification and development before it can explain the data that constitute its main source of support. Supplementary materials relevant to this article can be downloaded from the Psychonomic Society’s Norms, Stimuli, and Data Archive, www.psychonomic .org/archive.     

Directed search through autobiographical memory

Two experiments were designed to study retrieval from a well-ordered set of overlearned information in long-term autobiographical memory. In Experiment 1, each of 161 university students was asked to recall the name of one teacher from each of the 12 preuniversity school years. Recall was cued in forward (Grades 1-12), backward (Grades 12-1), or random order. Backward-ordered search proved most efficient: Fewer students failed to complete the task :in that search order, and those who did complete the task were faster than the successful students in the other search orders. Experiment 2 was similar to Experiment 1, except that the 148 students tested were asked to “think aloud” as they attempted recall. From the resulting protocols, 25 categories of verbal reports were identified, including four that reflected retrieval strategies. Omission errors (failures to recall teachers’ names) and, with one exception, frequencies of verbal reports decreased as recency increased. Taken together, the results of both experiments show that the recall of one item can indirectly aid the recall of contiguous items and that the probability of recalling an item from autobiographical memory is primarily a function of recency.     

Anxiety and Mood-congruent Autobiographical Memory: A Conceptual Failure to Replicate

This study further explored whether highly anxious participants exhibit a mood-congruent autobiographical memory bias, as was found in two previous studies (Burke & Mathews, 1992; Richards & Whittaker, 1990). The 74 high and low trait anxious participants retrieved personal memories to anxiety-related, neutral, and positive cue words, and were then asked to recall the original cue words. The study also explored how expression of emotional versus factual responses might affect a memory bias. On most dependent measures, no differences were found between anxiety groups. However, low anxious participants recalled more memories overall than high anxious participants. In addition, the emotions groups recalled more words at free recall than the facts groups. Findings fail to support previous studies that found an autobiographical memory bias to be associated with high anxiety, and cast more support for the mounting evidence against a mood-congruent memory bias in anxiety.     

Alcohol intoxication and memory for events: A snapshot of alcohol myopia in a real-world drinking scenario

Alcohol typically has a detrimental impact on memory across a variety of encoding and retrieval conditions (e.g., Mintzer, 2007; Ray & Bates, 2006). No research has addressed alcohol's effect on memory for lengthy and interactive events and little has tested alcohol's effect on free recall. In this study 94 participants were randomly assigned to alcohol, placebo, or control groups and consumed drinks in a bar-lab setting while interacting with a “bartender”. Immediately afterwards all participants freely recalled the bar interaction. Consistent with alcohol myopia theory, intoxicated participants only differed from placebo and control groups when recalling peripheral information. Expanding on the original hypervigilance hypothesis, placebo participants showed more conservative reporting behaviour than the alcohol or control groups by providing more uncertain and “don't know” responses. Thus, alcohol intoxication had confined effects on memory for events, supporting and extending current theories.     

The face of memory: experiential avoidance and facial expressions during the retrieval of autobiographical memories

ABSTRACT

Experiential avoidance refers to attempts to control or suppress unwanted thoughts, feelings and emotions. We investigated whether experiential avoidance is associated with fewer facial expressions during autobiographical retrieval (i.e. retrieval of memory for personal information). We invited participants to retrieve autobiographical memories, and recall was analysed by a facial analysis software that detects and classifies emotional expressions. Participants were divided into high vs. low experiential avoidance. Analysis showed fewer emotional facial expressions in participants with high experiential avoidance than in those with low experiential avoidance during autobiographical retrieval. This low emotional expression can be regarded as an attempt by individuals with high experiential avoidance to avoid communicating the emotional load to others. This low emotional expression can be also regarded as an attempt by individuals with high experiential avoidance to control or suppress the internal events that contribute to the appearance or persistence of unwanted emotional states during retrieval.     

Retrieval of past and future positive and negative autobiographical experiences

We studied retrieval-induced forgetting for past or future autobiographical experiences. In the study phase, participants were given cues to remember past autobiographical experiences or to think about experiences that may occur in the future. In both conditions, half of the experiences were positive and half negative. In the retrieval-practice phase, for past and future experiences, participants retrieved either half of the positive or negative experiences using cued recall, or capitals of the world (control groups). Retrieval practice produced recall facilitation and enhanced memory for the practised positive and negative past and future experiences. While retrieval practice on positive experiences did not impair the recall of other positive experiences, we found inhibition for negative past and future experiences when participants practised negative experiences. Furthermore, retrieval practice on positive future experiences inhibited negative future experiences. These positivity biases for autobiographical memory may have practical implications for treatment of emotional disorders.