The spacing effect in the free recall of homogeneous lists: present and accounted for

Memory performance nearly always improves as a function of the spacing between repetitions. However, previous studies indicated that college students exhibited no spacing effect in the free recall of lists composed exclusively of words sampled from a single semantic category. We explored this puzzling phenomenon in two experiments. We found that the spacing effect in free recall can occur with homogeneous lists. Most interestingly, the effect seems to depend on the number of items (lag) separating spaced repetitions. Short lags between spaced repetitions yield a spacing effect, whereas longer lags do not.     

Strategies in the recall of clusterable lists

The present study assessed the effectiveness of a multi-session training aproach intended to teach mildly retarded adolescents to discover and utilize categorical list structure. The performance of a group of trained retarded individuals was compared with that of another group of retarded individuals who had simply received practice with the training materials. The performance of both retarded groups was evaluated relative to that of a group of equivalent-CA normal adolescents. Recall transfer with a new word list was indicated by the finding that trained retarded subjects achieved a criterion of perfect recall in fewer trials than untrained retarded subjects. Differences in the use of categorization strategies by normal and retarded subjects were interpreted in the light of the automatic-controlled processing distinction of Schneider and Shiffrin (1977).     

Memory for lists of spatial events in the rat

Three experiments are reported in which rats were presented with lists of spatial events or responses in distinct visual contexts, and retention subsequently was measured for the events occuring at each serial position. In Experiments 1 and 2, lists contained different numbers of forced choices on successively presented T-mazes, and memory for each serial position was tested on each trial. In Experiment 3, lists were made up of different numbers of forced entries into randomly ordered arms on the eight-arm radial maze, and memory for one serial position was probed on each trial. All three experiments yielded serial position curves which demonstrated recency effects but no primacy effects. Comparisons of retention for different list lengths within each experiment indicated that retention of shorter lists was equivalent to retention of the final items of longer lists and superior to retention of the initial items on longer lists. This pattern of results indicated that there was no evidence of proactive inhibition in the serial position curves. Analysis of input and output interference effects and the results of control tests suggested that both retroactive inhibition and time-based forgetting processes were responsible for recency effects.     

自我概念长时记忆表征的性别特征:自我参照实验范式的检验

记忆的自我参照效应实验范式,常被用来探讨自我概念长时记忆表征问题。不同于以往研究,本研究将作为记忆材料的人格词汇区分为两种性别特征,以此来探讨自我概念长时记忆表征的性别化问题。实验设计为2(被试:男性与女性)×2(编码方式:自我参照编码与语义编码)×2(记忆项目类别:男性特征人格词汇与女性特征人格词汇)的混合因素设计。首先,实验结果进一步验证了自我参照效应的存在。其次,研究发现男性被试对于男性特征人格词汇的自我参照效应,显著高于女性特征人格词汇;女性被试的情况正好相反。实验结果表明,自我概念长时记忆表征系统对那些与自我性别相一致的人格特征词汇有比较好的组织编码形式,反映出自我对性别的认同。     

A model for free recall of two lists: Individual recall sequences and the effect of list-2-dominance

A free recall model which assumes a probability search for two kinds of items within one search set is outlined. Predictions for individual recall sequences are derived and an explanation for the effect of list-2-dominance is suggested. An index of dominance is also given.     

Memory for previous recall: a comparison of free and cued recall

Case studies of individuals who claimed to have recovered previously repressed memories of abuse during situations that involved memory cueing revealed that some individuals had discussed abuse with others during an earlier time period. Termed the ‘forgot‐it‐all‐along’ effect, this phenomenon has legal implications for statutes of limitations. Two experiments provide evidence for differences between free recall and more directed (recognition or cued recall) test conditions in the accuracy of memories for previous recall. Participants more often erred by claiming they had not previously remembered recognized (Experiment 1) or cued (Experiment 2) sentences than freely recalled sentences, and this difference was obtained even when the number of remembered sentences was equivalent across conditions (Experiment 2). These studies document that memory for previous recollection is less accurate for cued memories even when remembered events do not produce feelings of shock or surprise. Copyright © 2002 John Wiley & Sons, Ltd.     

Coding processes in the free recall of associated word lists

An experiment is reported on the free recall of lists of 18 words. The lists consisted of words that were strongly or weakly associated to the eliciting stimulus, were members of either a single category or more than one category and were arranged into sets of three associated words or six associated words. Each list was presented once only and free recall required after a filled interval of 18 s. One half of the subjects were provided with cues at recall: the remainder were given no assistance. Recall efficiency increased with association level and with restricted category membership of the words in a set. Clustering at recall (when adjusted for opportunity) was greater in the 6×3 lists than in the 3×6 lists. The provision of cues only led to a significant facilitation in recall with lists consisting of 6 sets of 3 words. A detailed analysis of the recall data suggested the importance of the category membership variable in the production of the later recall.     

Spacing and lag effects in free recall of pure lists

Repeating list items leads to better recall when the repetitions are separated by several unique items than when they are presented successively; thespacing effect refers to improved recall for spaced versus successive repetition (lag > 0 vs. lag = 0); thelag effect refers to improved recall for long lags versus short lags. Previous demonstrations of the lag effect have utilized lists containing a mixture of items with varying degrees of spacing. Because differential rehearsal of items in mixed lists may exaggerate any effects of spacing, it is important to demonstrate these effects in pure lists. As in Toppino and Schneider (1999), we found an overall advantage for recall of spaced lists. We further report the first demonstration of a lag effect in pure lists, with significantly better recall for lists with widely spaced repetitions than for those with moderately spaced repetitions.     

Rehearsal and retrieval processes in free recall of categorized lists

The relationships between rehearsal and subsequent retrieval characteristics were examined in the context of free recall of categorized lists. The results indicated a direct correspondence between the frequency of rehearsal and the order and speed of retrieval within categories. The same relationship obtained for the categories themselves. It was suggested that both retrieval time and order effects can be predicted in terms of the organization of input processing and the resultant repetition frequency of categories and exemplars.     

Retrieval strategies in recall of natural categories and categorized lists

Experiments 1 and 2 examined the effect of retrieval strategies on 3 or 12 min of recall from a natural category. Experiment 3 examined the effect of strategy on 6 min of recall from a subset of a category presented as a list. In Experiments 1 and 2, a large recall deficit was produced by retrieval strategies involving recall in alphabetic order and by size of the words' referents, relative to free recall. In Experiment 3, four strategies, alphabetic, size, serial order, and free recall, gave similar levels of recall after 6 min, though the growth rate of the cumulative output functions differed among the strategies. An extension of the search of associative memory (SAM) model of Raaijmakers and Shiffrin was developed to explain these results; the new model postulates attention sharing among probe cues and the use of idiosyncratic strategies for free recall from natural categories.     

Memory for medical history: Accuracy of recall

Medical diagnosis often depends on the ability of patients to recall and report their medical history. In this study 104 people kept health diaries for 3 months, recording the incidence, frequency, data, duration, and severity of health events (symptoms, illnesses, injuries, visits to health professionals, and medication). Memory for the events recorded was tested immediately after the diary-keeping period or at 1 month or 3 months later. Effects of age, gender, education, health status, anxiety, and retention interval were observed. With a free recall procedure only 47 per cent of health events were recalled. Following the free recall two different kinds of intervention were compared. Use of a recognition checklist yielded recall of 29 per cent of the forgotten events but with a cognitive interview procedure only 6 per cent of the forgotten items were retrieved.     

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).     

Time preferences for the very long term

Many important decisions concern outcomes delayed by decades or centuries. Whereas some economists have argued that inter-generational discount rates should be lower than intra-generational rates, three experiments found that inter- and intra-generational discount rates were quite similar. Experiment 1 found that discount rates for long delays (30-900 years) were lower than those for shorter delays (1-30 years) but that, holding delay constant, discount rates for outcomes occurring to future generations were similar to those for outcomes occurring to the present generation. Experiment 2 compared inter-generational discount rates for three different types of outcomes and found similar discount rates for saving lives, improving health, and financial benefits. Experiment 3 found similar inter-generational discounting of life-saving programs that benefit people close to or distant from the decision maker. These studies indicate that the discount rate applied to outcomes occurring to future generations depends on the length of the time delay but not on other factors.     

The effects of mediated word lists on false recall and recognition

False memory effects were explored using unrelated list items (e.g., slope, reindeer, corn) that were related to mediators (e.g., ski, sleigh, flake) that all converged upon a single nonpresented critical item (CI; e.g., snow). In Experiment 1, participants completed either an initial recall test or arithmetic problems after study, followed by a final recognition test. Participants did not falsely recall CIs on the initial test; however, false alarms to CIs did occur in recognition, but only following an initial recall test. In Experiment 2, participants were instructed to guess the CI, followed by a recognition test. The results replicated Experiment 1, with an increase in CI false alarms. Experiment 3 controlled for item effects by replacing unrelated recognition items from Experiment 1 with both CIs and list items from nonpresented lists. Once again, CI false alarms were found when controlling for lexical characteristics, demonstrating that mediated false memory is not due simply to item differences.     

Memory for actions: Item and relational information in categorized lists

Enacting action phrases in subject-performed tasks (SPTs) leads to better free recall than hearing or reading the same materials in verbal tasks (VTs). This enactment effect is usually explained by better item-specific information in SPTs than in VTs. The role of relational information is controversial. In the present paper, we will take the multiple recall approach to study the role of item and relational information in memory for actions by computing the number of item gains and the number of item losses over trials. This approach has previously been applied to lists of unrelated action phrases. We applied it to categorically related lists, also allowing a measure of relational information by clustering scores. It was found that SPTs produced more item gains than VTs. This finding confirmed the assumption that SPTs provide better item-specific information than VTs. The number of item losses did not differ between VTs and SPTs. This finding suggests that relational information is equally provided by VTs and SPTs. However, the organizational scores showed a more differentiated picture. Clustering was greater in SPTs than in VTs with randomly presented lists, but not with blocked lists. We suggested that these results, as well as other findings from the literature, could be explained by distinguishing automatic and strategic processes and the types of item associations that are addressed by these processes.     

Serial recall of two-voice lists: Implications for theories of auditory recency and suffix effects

Substantial recency effects are found in immediate serial recall of auditory items. These recency effects are greatly reduced when an irrelevant auditory stimulus (a stimulus suffix) is presented. A number of accounts that have been proposed to explain these phenomena assume that auditory items are susceptible to masking or overwriting in memory. Later items overwrite earlier items, leading to an advantage for the last item, unless it is masked by a suffix. This assumption is called into question by evidence that presenting list items in two voices has no beneficial effect in immediate serial recall. In addition, it is shown that suffix effects on both terminal and preterminal list items are influenced by the physical similarity of the suffix to the terminal item and not by the physical similarity of the suffix to preterminal items.     

Memory Functioning in Children with Reading Disabilities and/or Attention Deficit/Hyperactivity Disorder: A Clinical Investigation of their Working Memory and Long-Term Memory Functioning

We examined memory functioning in children with reading disabilities (RD), Attention deficit/hyperactivity disorder (ADHD), and RD/ADHD using a clinic sample with a clinical instrument: the Children's Memory Scale, enhancing its generalizability. Participants included 23 children with RD, 30 with ADHD, 30 with RD/ADHD, and 30 controls. Children with RD presented with reduced verbal short-term memory (STM) but intact visual STM, central executive (CE), and long-term memory (LTM) functioning. Their deficit in STM appeared specific to tasks requiring phonetic coding of material. Children with ADHD displayed intact CE and LTM functioning but reduced visual-spatial STM, especially when off stimulant medication. Children with RD/ADHD had deficits consistent with both disorders.     

On the nature of talker variability effects on recall of spoken word lists.

In a recent study, Martin, Mullennix, Pisoni, and Summers (1989) reported that subjects' accuracy in recalling lists of spoken words was better for words in early list positions when the words were spoken by a single talker than when they were spoken by multiple talkers. The present study was conducted to examine the nature of these effects in further detail. Accuracy of serial-ordered recall was examined for lists of words spoken by either a single talker or by multiple talkers. Half the lists contained easily recognizable words, and half contained more difficult words, according to a combined metric of word frequency, lexical neighborhood density, and neighborhood frequency. Rate of presentation was manipulated to assess the effects of both variables on rehearsal and perceptual encoding. A strong interaction was obtained between talker variability and rate of presentation. Recall of multiple-talker lists was affected much more than single-talker lists by changes in presentation rate. At slow presentation rates, words in early serial positions produced by multiple talkers were actually recalled more accurately than words produced by a single talker. No interaction was observed for word confusability and rate of presentation. The data provide support for the proposal that talker variability affects the accuracy of recall of spoken words not only by increasing the processing demands for early perceptual encoding of the words, but also by affecting the efficiency of the rehearsal process itself.     

Working memory capacity and the spacing effect in cued recall

Spacing repetitions typically improves memory (the spacing effect). In three cued recall experiments, we explored the relationship between working memory capacity and the spacing effect. People with higher working memory capacity are more accurate on memory tasks that require retrieval relative to people with lower working memory capacity. The experiments used different retention intervals and lags between repetitions, but were otherwise similar. Working memory capacity and spacing of repetitions both improved memory in most of conditions, but they did not interact, suggesting additive effects. The results are consistent with the ACT-R model’s predictions, and with a study-phase recognition process underpinning the spacing effect in cued recall.     

Role of study strategy in recall of mixed lists of common and rare words

Experiment 1 confirmed previous findings that common words are more recallable than are rare words when the 2 kinds of words are presented in separate lists but not when they are presented in the same list. Experiment 2 showed much the same pattern when an orienting task was performed during word presentation. In Experiment 3 common words were found to be more recallable than rare words even for mixed lists when no warning was given of the memory test, although the effect was less pronounced than for pure lists. In Experiment 4 stronger measures were taken to preclude anticipation of the memory test, and the effect of word commonness was found to be just as pronounced with mixed lists as it was with pure lists. It was suggested that lists are studied in a way believed to optimize recall and that mixed lists foster a strategy of favoring the rare words.