Examining the relationship between free recall and immediate serial recall: The effect of concurrent task performance.

In 3 experiments, participants saw lists of 16 words for free recall with or without a 6-digit immediate serial recall (ISR) task after each word. Free recall was performed under standard visual silent and spoken-aloud conditions (Experiment 1), overt rehearsal conditions (Experiment 2), and fixed rehearsal conditions (Experiment 3). The authors found that in each experiment, there was no effect of ISR on the magnitude of the recency effect, but interleaved ISR disrupted free recall of those words that would otherwise be rehearsed. The authors conclude that ISR and recency cannot both be outputs from a unitary limited-capacity short-term memory store and discuss the possibility that the process of rehearsal may be common to both tasks. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

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 (see record 1996-93836-009) 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. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Using overt rehearsals to explain word frequency effects in free recall.

Three experiments examined the word frequency effect in free recall using the overt rehearsal methodology. Experiment 1 showed that lists of exclusively high-frequency (HF) words were better recalled, were rehearsed more, and were rehearsed to more recent serial positions than low-frequency (LF) words. A small HF advantage remained even when these 2 variables were equated. Experiment 2 showed that all these effect, were much reduced with mixed lists containing both HF and LF words. Experiment 3 compared pure and mixed lists in a within-subject design and confirmed the findings of Experiments 1 and 2. It is argued that number of rehearsals, recency of rehearsals, and strength of interitem association cause the word frequency effect in free recall. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Dissociating conditional recency in immediate and delayed free recall: A challenge for unitary models of recency.

Temporal distinctiveness models of recency in free recall predict that increasing the delay between the end of sequence and attempting recall of items from that sequence will reduce recency. An empirical dissociation is reported here that violates this prediction when the delay is introduced by the act of recall itself. Analysis of data from a number of previously published free recall studies shows that when the assumed availability of final list items is taken into account, recency increases across the first few output positions in immediate recall despite the delay introduced by recalling items; no such change, with a trend to decreasing recency, is observed in delayed recall. Simulations are presented, showing that 2 models accounting for recency in free recall, the temporal context model (M. W. Howard & M. J. Kahana, 2002) and the SIMPLE model (G. D. A. Brown, I. Neath, & N. Chater, 2007), are unable to account for this novel pattern of data. Further simulations show that the results are consistent with a short-term buffer contributing to recency in immediate free recall and that ordered probing of items may also contribute to this effect; both of these are consistent with the formulation of a short-term buffer akin to models of serial recall. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A common basis for recency effects in immediate and delayed recall.

Examined the effects of word frequency and list length on the long-term serial position curve in 2 experiments, using a total of 68 undergraduates. In Exp I, the object was to find a distractor activity that would be sufficient to eliminate the recency effect in conventional free recall. In Exp II, whether list length would show a similar pattern of effects in a continuous-distractor paradigm was examined. Results demonstrate that word frequency and list length had the same effects on the serial-position curve in the continuous-distractor paradigm of delayed recall that they had previously been shown to have in immediate recall. High word frequency and shorter lists led to improved recall of preterminal items but did not influence recall of terminal items. Results suggest that the same processes underlie recency effects in the 2 paradigms and that accounts that attribute recency effects to primary (or short-term) memory are inadequate. (41 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Immediate and delayed recall of words and pictures.

Examined free and serial recall of words and pictures associates in 3 experiments with 156 Ss. In immediate free recall, presentation of pictorial material increased only the secondary memory component of recall, relative to conditions involving presentation of verbal materials. No such facilitation occurred in immediate serial recall. In delayed recall tests, negative recency effects were obtained only for verbal materials, in both free and serial recall. Recency effects were either nonnegative or positive with pictures as to-be-remembered material. Results are discussed in terms of the locus of word-picture differences and the adequacy of verbal memory model explanations for them. (French summary) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The Effect of the Length of To-Be-Remembered Lists and Intervening Lists on Free Recall: A Reexamination Using Overt Rehearsal.

In 3 experiments, the authors investigated the effects of to-be-remembered (TBR) and intervening list length on free recall to determine whether selective rehearsal could explain the previous finding that recall was affected only by TBR list length. In Experiments 1 (covert rehearsal) and 2 (overt rehearsal), participants saw 5- and 20-word lists and had to recall the list prior to that last presented list. In Experiment 3, either 1 or 2 lists were presented, and recall of TBR list was postcued. Recall proportion decreased with increased TBR list length. Moreover, the authors found extended recency effects when recall was replotted by when words were last rehearsed (Experiments 2 and 3) and an effect of intervening list length when rehearsal was reduced (Experiment 3). (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Memorial and strategic determinants of tactile recency.

Across 4 experiments, recency arising from the presentation of 5-item tactile lists was assessed with immediate and delayed recall with or without a same-modality suffix. The lists were presented with or without concurrent verbalization and at rates varying from 0.5 s to 2 s per item. Delaying recall or the addition of a suffix impaired recency both in the absence of concurrent verbalization during list presentation and at the 1-s presentation rate. In contrast, both concurrent verbalization during list presentation and a 0.5-s presentation rate restored recency for both the delayed recall and suffix conditions. This pattern of data is problematic for sensory memory and for trace discriminability accounts of modality and suffix effects. It is suggested that a sensory memory account together with an attention-biasing strategy by which limited encoding resources are diverted toward the terminal list item can better accommodate the data. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

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. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Dissociation between recency and span: Neuropsychological and experimental evidence.

This article reports dissociations between verbal span and the recency portion of the serial position curve in immediate free recall, in 2 neuropsychological case studies and in 3 experiments with normal participants. Patient A. N. presented with an impaired serial verbal span while showing an intact recency effect. The opposite pattern was observed in patient G. C., who despite a poor recency showed normal span in verbal serial recall tasks. Experiments 1 and 2 showed a recency effect with visually and auditory presented lists and written recall was resistant to the effects of articulatory suppression and of irrelevant speech, but was disrupted by the suffix effect. Experiment 3 showed that in contrast with recency, memory span was affected by articulatory suppression and irrelevant speech during presentation but not by a suffix. These findings are not consistent with the idea that span and recency measure aspects of the same memory system. Moreover, in clinical practice, they should not be used as equivalent alternatives. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Evolution on a volcanic conveyor belt: using phylogeographic reconstructions and K-Ar-based ages of the Hawaiian Islands to estimate molecular evolutionary rates

This article reports dissociations between verbal span and the recency portion of the serial position curve in immediate free recall, in 2 neuropsychological case studies and in 3 experiments with normal participants. Patient A. N. presented with an impaired serial verbal span while showing an intact recency effect. The opposite pattern was observed in patient G. C., who despite a poor recency showed normal span in verbal serial recall tasks. Experiments 1 and 2 showed a recency effect with visually and auditory presented lists and written recall was resistant to the effects of articulatory suppression and of irrelevant speech, but was disrupted by the suffix effect. Experiment 3 showed that in contrast with recency, memory span was affected by articulatory suppression and irrelevant speech during presentation but not by a suffix. These findings are not consistent with the idea that span and recency measure aspects of the same memory system. Moreover, in clinical practice, they should not be used as equivalent alternatives.     

Temporal associations and prior-list intrusions in free recall.

When asked to recall the words from a just-presented target list, subjects occasionally recall words that were not on the list. These intrusions either appeared on earlier lists (prior-list intrusions, or PLIs) or had not appeared over the course of the experiment (extra-list intrusions). The authors examined the factors that elicit PLIs in free recall. A reanalysis of earlier studies revealed that PLIs tend to come from semantic associates as well as from recently studied lists, with the rate of PLIs decreasing sharply with list recency. The authors report 3 new experiments in which some items in a given list also appeared on earlier lists. Although repetition enhanced recall of list items, subjects were significantly more likely to make PLIs following the recall of repeated items, suggesting that temporal associations formed in earlier lists can induce recall errors. The authors interpret this finding as evidence for the interacting roles of associative and contextual retrieval processes in recall. Although contextual information helps to focus recall on words in the target list, it does not form an impermeable boundary between current- and prior-list experiences. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Examining the relationship between free recall and immediate serial recall: The effects of list length and output order.

In 4 experiments, participants were presented with lists of between 1 and 15 words for tests of immediate memory. For all tasks, participants tended to initiate recall with the first word on the list for short lists. As the list length was increased, so there was a decreased tendency to start with the first list item; and, when free to do so, participants showed an increased tendency to start with one of the last 4 list items. In all tasks, the start position strongly influenced the shape of the resultant serial position curves: When recall started at Serial Position 1, elevated recall of early list items was observed; when recall started toward the end of the list, there were extended recency effects. These results occurred under immediate free recall (IFR) and different variants of immediate serial recall (ISR) and reconstruction of order (RoO) tasks. We argue that these findings have implications for the relationship between IFR and ISR and between rehearsal and recall. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Sources of recency effects in free recall.

Discusses evidence casting doubt on the primary-memory account of the recency effect in recall and reviews an alternate account that attributes recency to the use of temporal or contextual cues. The discussion is presented in the paradigm of free recall. The recency effect refers to the fact that when people memorize a list of words, they tend to recall items at the end of the list more often than those in the middle. Recency effects have often been attributed to output from primary memory, a short-term memory buffer system. Evidence that recency effects can be found in the absence of primary memory (in conditions of concurrent distraction, multicategory lists, interactions of other independent variables with serial position, negative recency effects, and auditory recency) is reviewed. It is concluded that primary-memory theories are no longer adequate accounts for the recency effect. A temporal-contextual theory of the recency effect is discussed as a plausible alternative account, although these accounts are not fully developed or tested. (108 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A recency-based account of the primacy effect in free recall.

Seven experiments investigated the role of rehearsal in free recall to determine whether accounts of recency effects based on the ratio rule could be extended to provide an account of primacy effects based on the number, distribution, and recency of the rehearsals of the study items. Primacy items were rehearsed more often and further toward the end of the list than middle items, particularly with a slow presentation rate (Experiment 1) and with high-frequency words (Experiment 2). Recency, but not primacy, was reduced by a filled delay (Experiment 3), although significant recency survived a filled retention interval when a fixed-rehearsal strategy was used (Experiment 4). Experimenter-presented schedules of rehearsals resulted in similar serial position curves to those observed with participant generated rehearsals (Experiment 5) and were used to confirm the main findings in Experiments 6 and 7. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The influence of word frequency on recency effects in directed free recall.

Leading theoretical explanations of recency effects are designed to explain the reported absence of a word frequency effect on recall of words from recency serial positions. The present study used a directed free-recall procedure (J. I. Dalezman, 1976) and manipulated the frequency composition of the word lists (pure and mixed). Overall, with pure lists, a greater proportion of high-frequency (HF) words were recalled than low-frequency (LF) words, and with mixed lists, a greater proportion of LF words were recalled than HF words. Of importance, this recall advantage for one frequency over the other as a function of list composition was evident across the last three serial positions, indicating an influence of word frequency on recency effects that is dependent on the frequency composition of the lists. These results challenge one of the major assumptions on which several theories of recency effects have been based. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Pop-out into memory: A retrieval mechanism that is enhanced with the recall of subject-performed tasks.

Subject-performed tasks (SPTs; i.e., carrying out the actions during study) improve free recall of action phrases without enhancing relational information. By this mechanism, items pop into a person's mind without active search, and this process especially extends the recency effect. The authors demonstrated the existence of the extended recency effect and its importance for the SPT recall advantage (Experiments 1 and 2). Carrying out the action and not semantic processing caused the effect (Experiment 3). The extended recency effect was also not a consequence of a deliberate last-in, first-out strategy (Experiment 4), and performing a difficult secondary task (an arithmetic task) during recall reduced memory performances but did not influence the extended recency effect (Experiment 5). These data support the theory that performing actions during study enhances the efficiency of an automatic pop-out mechanism in free recall. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Memory deficit caused by compressed air equivalent to 36 meters of seawater.

Twenty-four students from a diving school undertook a hyperbaric chamber dive to a pressure equal to 36 m of seawater. Tests of cognitive function and manual dexterity, performed in the chamber during the 35-min bottom time and before, or after, the dive included immediate and delayed free recall of words presented as 7 lists of 15 each, recognition of previously presented words, number identification, and a forceps pickup of ball bearings. Delayed free recall and immediate free recall (primacy region) were significantly impaired, whereas manual dexterity and recognition memory were not. These are in keeping with previously reported findings but indicate that significant impairment of memory may occur in experienced divers at operational depths for air diving. Lack of effect on recognition memory suggests that cueing strategies might be useful for debriefing divers. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Auditory and temporal factors in the modality effect.

Conducted 5 experiments in which 120 undergraduates read 9-digit memory lists from a CRT for immediate recall. Results indicate that reading aloud always produced a localized and reliable advantage for the last item when compared with reading silently. Results from Exps I and II, which involved whispered and mouthed lists with or without simultaneous broadband noise, do not support expectations derived from the theory of precategorical acoustic storage developed by the author and J. Morton (1969). Results from Exps III–V show no enhancement of recency in the silent conditions when the digits were drawn or spelled gradually on the screen, a result that is inconsistent with a changing-state hypothesis (i.e., changing-state information produces exaggerated recency). It is concluded that the classic auditory-visual modality effect is large and reliable, but still poorly understood. (49 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Creating false memories: Remembering words not presented in lists.

Two experiments (modeled after J. Deese's 1959 study) revealed remarkable levels of false recall and false recognition in a list learning paradigm. In Exp 1, Ss studied lists of 12 words (e.g., bed, rest, awake); each list was composed of associates of 1 nonpresented word (e.g., sleep). On immediate free recall tests, the nonpresented associates were recalled 40% of the time and were later recognized with high confidence. In Exp 2, a false recall rate of 55% was obtained with an expanded set of lists, and on a later recognition test, Ss produced false alarms to these items at a rate comparable to the hit rate. The act of recall enhanced later remembering of both studied and nonstudied material. The results reveal a powerful illusion of memory: People remember events that never happened. (PsycINFO Database Record (c) 2010 APA, all rights reserved)