Limitations to the spacing effect: demonstration of an inverted u-shaped relationship between interrepetition spacing and free recall

The spacing effect refers to the finding that memory for repeated items improves when the interrepetition interval increases. To explain the spacing effect in free-recall tasks, a two-factor model has been put forward that combines mechanisms of contextual variability and study-phase retrieval (e.g., Raaijmakers, 2003; Verkoeijen, Rikers, & Schmidt, 2004). An important, yet untested, implication of this model is that free recall of repetitions should follow an inverted u-shaped relationship with interrepetition spacing. To demonstrate the suggested relationship an experiment was conducted. Participants studied a word list, consisting of items repeated at different interrepetition intervals, either under incidental or under intentional learn instructions. Subsequently, participants received a free-recall test. The results revealed an inverted u-shaped relationship between free recall and interrepetition spacing in both the incidental-learning condition and the intentional-learning condition. Moreover, for intentionally learned repetitions, the maximum free-recall performance was located at a longer interrepetition interval than for incidentally learned repetitions. These findings are interpreted in terms of the two-factor model of spacing effects in free-recall tasks.     

What can we learn about immediate memory from the development of children's free recall?

We ask the question: Which aspects of immediate memory performance improve with age? In two studies, we reexamine the widely held view that primary memory capacity estimates derived from children's immediate free recall are age invariant. This was done by assessing children's immediate free-recall accuracy while also measuring the order in which they elected to recall items (Experiment 1) and by encouraging children to begin free recall with items from towards the end of the presented list (Experiment 2). Across samples aged between 5 and 8 years we replicated the previously reported age-related changes in free-recall serial position functions when aggregated across all trials of the standard task, including an absence of age differences in the recency portion of this curve. However, we also show that this does not reflect the fact that primary memory capacity is constant across age. Instead, when we incorporate order of report information, clear age differences are evident in the recall of list-final items that are output at the start of a participant's response. In addition, the total amount that individuals recalled varied little across different types of free-recall tasks. These findings have clear implications for the use of immediate free recall as a means of providing potential indices of primary memory capacity and in the study of the development of immediate memory.     

Effects of types of elaboration on children's memories of a story: interaction with academic performance

Two experiments compared the effectiveness of three types of elaboration on incidental and intentional memory for a story: self-generated, self-choice, and experimenter-provided elaboration. In Exp. 1, using the incidental memory paradigm, second graders listened to a fantastic story and then, in the self-generated condition, answered a "why" question about a particular topic in the story. In the self-choice condition, they chose one of the alternative answers to the question and in the experimenter-provided condition, judged the appropriateness of each of two provided answers. This was followed by free-recall and cued-recall tests. Subjects were categorized into two groups, good and poor academic achievers in terms of academic scores in four subject matter areas. For good academic achievers, self-choice elaboration led to a better cued recall than the other two elaboration types. The cued-recall performance of poor achievers was not different with the three conditions. In Exp. 2, using the intentional memory paradigm, the subjects intended to learn a different story and then performed the same procedure as Exp. 1. For poor achievers, self-choice elaboration led to a worse free recall than the other elaboration types, but the free recall of good achievers was not significantly different for the three types of elaboration. The results were interpreted as showing that the effects of self-choice elaboration on incidental and intentional memory were correlated with subjects' academic performance.     

The Perception of Mechanical Vibration: III. The Frequency Function

Three studies of male and female undergraduates examined the effects of incidental orienting tasks on the free recall of concrete nouns. In Experiments 1 (between-Ss design N = 53) and 2 (within-Ss design N = 54) semantic orienting tasks resulted in recall that was equal to or higher than recall following intentional learning. Nonsemantic orienting tasks produced poorest recall. In Experiment 3 (N = 59), Ss performed a word recognition task between two free-recall trials. The target and distractor words were either acoustically, orthographically, or semantically related or were unrelated to each other. On the second free-recall trial, recall was highest for target words that had been paired with semantically related distractors. The results of the three experiments add to the growing support for a levels-of-processing model of memory.     

The recall of relevant and incidental dimensional values as a function of perceptual salience, congitive set, and age.

In two experiments, subjects were presented an array of compound stimuli consisting of values from four, salience-assessed dimensions. Solution to an initial problem required recall of the array locations of values from only the most salient dimension. In addition to perceptual salience, instructions designed to establish cognitive sets for remembering value locations of certain dimensions were varied to explore the roles of these perceptual and cognitive variables in determining recall. In Experiment I, which involved subjects from grades kindergarten, third, and sixth, older subjects recalled more incidental as well as relevant information than younger subjects, and although instructions to remember values of a less salient incidental dimension facilitated their recall, the same instructions also facilitated the recall of values of a more salient incidental dimension even though no reference was made to those values. In Experiment II, adult recall of both relevant and incidental information was affected by instructions about differing numbers and types of dimensions. Adults and the oldest children did not differ in total information recalled, and there was no evidence for an increase with age in the cognitive ability to select only that information that was relevant to solving the initial problem. The results were discussed in terms of developmental changes in memory capacity and the absolute salience of the task information.     

Facilitation of recall with intralist cues: Time-dependent characteristics of cued recall

List items were given as retrieval cues in a free-recall experiment which factorially combined the presence or absence of cues with the amount of time allowed for use of each cue (10 sec or 30 sec). A categorizable list of 75 randomly presented words was learned, and 48 h later a free-recall test trial was given, followed by a final memory search task. During the final task, cued subjects received words from categories that had not been recalled during the free-recall test. With both time intervals, cued subjects recalled more words than noncued subjects, indicating that random presentation of categorized words does not necessarily preclude the observation of a cueing effect with list items, as has been reported previously. The composition of recall, whether from previously recalled or nonrecalled categories, varied as a function of time for both groups. The results were interpreteod in terms of retrieval strategies employed by cued and noncued subjects and the effect of time on these strategies.     

Self-esteem and formality of instructions as variables influencing selective recall

The present study attempted to determine whether the selective recall phenomenon was related to self-esteem. The selective recall phenomenon is the inferior recall of interrupted tasks in a formal (ego-threatening) situation, relative to the recall of interrupted tasks in an informal (nonthreatening) situation. Two hundred eleven college students responded to a self-esteem inventory and then were given formal or informal instructions. They then worked on 16 tasks, and were interrupted on 8 but were allowed to complete 8. Finally, an unexpected free-recall test of task solutions was administered. Only subjects low in self-esteem exhibited the selective recall pattern. It was hypothesized that in a formal situation, interrupted activities were viewed as failures. It was assumed that the recall of failures was particularly threatening to low-self-esteem subjects, resulting in selective forgetting or selective storage of solutions. It was also found that all subjects recalled solutions from completed tasks more frequently than solutions from interrupted tasks. Several interpretations for the latter phenomenon were suggested, including a dual mechanism involving both motivation persistence and motivation reduction, and the incorporation of information into a self-referent schema.     

The attentional demands of mnemonic control processes

In order to assess the processing (i.e., attentional) demands of different control processes, subjects were required to perform a secondary choice reaction time task in addition to primary verbal tasks. The performance of the secondary task yielded a measure termedexpended processing capacity (EPC), which was used to infer the attentional demands of the primary tasks. Two factors, mediator type (experimenter-supplied vs. subject-generated) and intentionality (incidental vs. intentional), were varied in a paired-associate situation in an effort to affect the degree of elaboration processing. Only mediator type had an effect on recall accuracy and on EPC during both initial processing and recall. Subject-generated mediators resulted in higher recall and in higher EPC during initial processing, but in lower EPC during recall, than did experimenter-supplied mediators. Implications of these findings are discussed.     

Locus of control and the age difference in free recall from episodic memory.

The authors investigated the relation of locus of control (LOC) to age differences in free-recall memory performance. Older and younger participants completed P. C. Duttweiler's (1984) Internal Control Index (ICI) and subsequently performed free-recall memory tasks. Compared with the younger participants, the older participants exhibited poorer recall with more intrusions and uncorrected repetition errors as well as reduced categorical clustering. For the older participants with less internal LOC, recall proportion and item-pair associative recall clustering were lower than for the older participants with more internal LOC. By contrast, the younger participants did not exhibit any LOC effects in their recall performance. The results suggest that a differential memory organization deficit may underlie the age differences in free recall among individuals varying in LOC when they are performing an intentional learning task. This deficit is discussed in terms of a reduced-inhibition account of cognitive aging.     

Children's and adults' recall of sex‐stereotyped toy pictures: Effects of presentation and memory task

Gender schema theories predict a memory bias toward sex‐congruent information. The present study examined how presentation of stimuli and encoding conditions influence gender schematic processing in children and adults. One hundred and sixty 5‐ to 13‐year olds and adult males and females viewed 36 sex‐stereotyped toy pictures that were presented in a static and dynamical way. Half of the participants were asked to memorize the pictures (intentional memory) and half were not told that they would be expected to later recall the pictures (incidental memory). Weak gender schematic processing was observed only during the incidental memory task. Children and adults recalled more static than dynamic gender‐stereotyped pictures, and performance was superior in the intentional than in the incidental memory condition. Gender schematic processing was similar across the age groups. In addition, participants were more likely to recall male‐stereotyped toys. Implications for gender schema theories and education are discussed. Copyright © 2004 John Wiley & Sons, Ltd.     

Hypermnesia: the role of repeated testing

The present study was designed to determine whether the increased recall of pictures across repeated tests (hypermnesia) is due to increasing strength of imaginal traces during the retention interval or to increased retrieval practice from prior tests. Subjects studied 60 pictures and then recalled them after various delays that were filled with instructions and, in two cases, reading a passage. Recall on a first test showed no change with retention interval. With retention interval held constant, however, the number of pictures recalled varied directly with the number of prior tests subjects had been given. This finding points up the critical nature of retrieval factors in producing hypermnesia.     

Recall by expert medical practitioners and novices as a record of processing attention

Using recall of clinical protocols as a measure of expertise in medicine has yielded disappointingly small effects. Experiments using recall of clinical laboratory data are presented to provide an explanation. In one experiment, subjects either deliberately memorized or first diagnosed and then were incidentally asked for memory. With incidental instructions, experts recalled over twice as much data as did students, but with memorization instructions, student performance approximated that of experts. Experts also showed a large advantage over students in incidental recall of data that were not relevant to the problem solution. These results suggest that expert processing in this "discrete, independent inputs" domain requires effortful analysis with minimal reliance on default values, rather than relatively effortless pattern perception reported in highly visual areas of expertise. For this area, intentional memory is a misleading measure of expertise. However, incidental memory is a valuable measure of processing during diagnosis.     

Memory for meaning in skilled and unskilled readers

Skilled and unskilled readers from grades 3, 5, and 7 (9, 11, and 13 years of age, respectively) performed one of three memory tasks on a randomized list of primary word associates. One group rated each word as “good” or “bad” (incidental semantic task), another group produced a rhyming word for each list word (incidental rhyming task), and a third group attempted to memorize the list (intentional learning task). The recall results indicated equivalent recall for skilled and unskilled readers at all grades on the rhyming and intentional tasks; whereas, skilled readers were superior to unskilled readers on the semantic task. A clustering analysis produced a similar effect as skilled readers, who performed the semantic task, tended to cluster semantically-associated words together during recall more readily than unskilled readers. The results were construed as evidence for reading-skill differences in the semantic encoding of individual words.     

Test expectancy and question answering in prose processing

Two experiments were conducted to study the effects of expectanices about test format (recall versus recognition) upon the retention of information from prose. In each study subjects expecting recall recalled better than those expecting a multiple-choice test. Serial position analysis in Experiment 1 suggested differential use of study time in groups expecting different types of test. Examination of study time use in Experiment 2 indicated that subjects expecting multiple-choice showed greater variability in the use of time spent reading prose segments. They were also more likely to employ idiosyncratic orders of reading segments. In general the results seem compatible with the theoretical model of Gillund and Shiffrin (1984) emphasizing the ratio of two types of coding.     

Effects of short-term retrieval on adult age differences in long-term recall of actions.

In Experiment 1 young and elderly subjects either recalled or repeated after every block of 4 actions, whereas control subjects received neither interpolated short-term recall nor action repetition. On a later long-term memory test, experimental subjects, regardless of age or condition, recalled slightly more actions than control subjects. In Experiment 2 young adult and elderly subjects received 12 short-term memory trials in which 2 actions were performed on each trial, but only 1 was cued for recall after a brief retention interval filled with a distracting activity. On a later long-term memory test for the actions performed on the short-term trials, both young and elderly subjects recalled significantly more previously cued than noncued actions. The Age X Cuing Condition interaction was negligible. Prior retrieval of actions appears to enhance later recall regardless of age but seemingly only when prior retrieval requires considerable cognitive effort (as in Experiment 2).     

Heart rate, recall, and reaction-time measures of levels of processing

A problem of circularity emerges in any attempt to index depth by retention alone. In the present study, reaction time (RT), and heart-rate response were used to index the three qualitatively distinct levels of physical, phonemic, and semantic processing. An additional objective was to distinguish between the three levels under incidental vs intentional learning conditions. Subjects were 46 male undergraduates who were given 30 trials. A trial consisted of the presentation of an orienting question and an imperative word-stimulus separated by a 6-sec. interval. There were three types of questions in order to induce processing to one of the three target levels. The results indicated that recall as well as heart-rate acceleration distinguished between two (physical vs phonemic and semantic) rather than three levels of processing in the incidental condition. Heart-rate change differentiated between incidental and intentional, the intentional condition showing a smaller change. Semantic and phonemic RTs were faster than physical RT, but there were no differences between semantic and phonemic RTs. Intentional recall was superior to incidental recall. It is suggested that psychophysiological indices can provide independent evidence for 'levels of processing.'     

Representation-saving effects of prior knowledge in memory for simple technical prose

Prior knowledge of the content of a passage should reduce the effort required to encode the passage and facilitate its recall. This paper presents such effects of prior knowledge upon comprehension and memory of simple technical prose. The basic procedure was to collect ratings of the amount of prior knowledge for individual passage sentences and individual subjects, and then to determine whether these familiarity ratings predicted study time and recall. In order to validate the rating method, and also to obtain data on prior knowledge of individual facts, subjects also completed an objective test of prior knowledge of the passage facts. Three different encoding-task conditions were used: a self-paced study task, a forced-pace study task, and an incidental-learning task. A cued-recall test followed each condition. In the self-paced task, readers studied unfamiliar material longer than familiar material, but recalled at the same level regardless of familiarity. In contrast, familiarity did predict recall in the forced-pace and incidental tasks. This task specificity is explained in terms of the subjects’ encoding strategies. The basic effect of prior knowledge can be explained not only by the elaboration principle, but also by a representation-saving principle, which is presented in a simulation model that can account for the effects of familiarity on study time.     

A developmental comparison of the effectiveness of encoding tasks.

In Experiment 1, the free-recall performance of young children, college students, and older adults was examined. Subjects encoded words by simply learning them, by studying them in either base or elaborate sentence frames, or by constructing sentences. Overall recall was better for the college students than for the children or for the older adults, and the college students recalled best in the simple learning condition. The young children recalled best in the sentence construction condition; recall by older adults did not vary as a function of the encoding tasks. In Experiment 2, college students and older adults recalled a categorized list, encoding the words by simply learning them, by studying them in elaborate sentence frames, or by completing word fragments. For both age groups, simple learning produced the highest level of recall. These results suggest that organization provides the most effective encoding system and that older adults may need a more obvious basis for organization than do younger adults. Younger and older adults recalled equally well only when organization was discouraged by conceptual processing.     

Memory for common objects: brief intentional study is sufficient to overcome poor recall of US coin features

Prior studies have explained the very poor recall for the features of a coin in terms of visual characteristics. Two experiments compared incidental exposure and intentional study of US coins on recall of their features. In Experiment 1, recall performance for a rarely seen Mercury dime after a 1-min study period was better than that for an unstudied penny, even when the test on the dime was delayed 1 week. In Experiment 2, participants studied the dime for 15, 30, 45, or 60 s. Recall of the dime was greater than that of the unstudied penny even with the shortest study interval. Thus, a high level of recall of a coin's features can be obtained with brief intentional study, and that level can be maintained across a long delay interval. These findings suggest that poor retention of coin features is due to incidental exposure rather than to visual characteristics. Copyright © 2004 John Wiley & Sons, Ltd.