A short‐term perceptual priming account of spacing effects in explicit cued‐memory tasks for unfamiliar stimuli

Memory for repeated items improves when presentations are spaced during study. This effect is found in explicit memory tasks using different types of material, different experimental paradigms, and in different subject populations. Two experiments are described where the spacing effect was assessed on a yes/no recognition memory task using words and nonwords as targets. The main results showed that changing the font between repeated occurrences of targets at study did not affect the spacing effect for words, even under shallow encoding conditions, but effectively removed the spacing effect with nonwords. In both experiments, the font manipulation was made between subjects, ruling out explanations in terms of differential attention to particular font conditions. These results provide further support for short‐term perceptual priming accounts of the spacing effect: Semantically‐based repetition priming affects memory for words; perceptual priming mechanisms affect memory for nonwords.     

Default spacing is the optimal spacing for word reading

Increased interletter spacing is thought to reduce crowding effects and to enhance fluent reading. Several studies have shown beneficial effects of increased interletter spacing on reading speed and accuracy, especially in poor readers. Therefore, increased interletter spacing appears to be a relatively easy way to enhance reading performance. However, in adult readers reading speed was shown to be impeded with increased interletter spacing. Thus, findings on interletter spacing are still inconclusive. In the current study we examined the effect of a range of interletter spacings (?0.5, default, 0.5, 1, 1.5, 2) on naming fluency of monosyllabic and bisyllabic words in beginning (Grade 2) and more advanced (Grade 4) readers. Additionally we tested the effects of spacing in a subsample of poor readers. In contrast to previous findings, neither beginning nor advanced readers benefited from an increase in interletter spacing. However, they did show reduced reading fluency when letter spacing was smaller than the default spacing, which may be indicative of a crowding effect. Poor readers showed a similar pattern. We conclude that an increase in interletter spacing has no effect on word naming fluency.     

The spacing effect in 4- to 9-year-old children

Experiment 1 of the current research failed to replicate Toppino and Di George’s (1984) finding that older children but not preschoolers showed a spacing effect. Instead, we obtained the spacing effect in all the age groups tested (preschool, kindergarten, first-grade, and third-grade children). The effect was demonstrated with two types of material, words and pictures. Experiment 2 focused on the role that very brief spacings, with no intervening items between repetitions, play in later retention. Age groups and materials were the same as in Experiment 1. Four different levels of spacing were included (0-, 1.1-,2.5-, and 5-sec intervals). The spacing effect was again obtained for all age groups with both words and pictures. The results of both experiments suggest that the spacing effect does not emerge with development.     

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.     

The shape of facial features and the spacing among them generate similar inversion effects: A reply to

It is often argued that picture-plane face inversion impairs discrimination of the spacing among face features to a greater extent than the identity of the facial features. However, several recent studies have reported similar inversion effects for both types of face manipulations. In a recent review, Rossion (2008) claimed that similar inversion effects for spacing and features are due to methodological and conceptual shortcomings and that data still support the idea that inversion impairs the discrimination of features less than that of the spacing among them. Here I will claim that when facial features differ primarily in shape, the effect of inversion on features is not smaller than the one on spacing. It is when color/contrast information is added to facial features that the inversion effect on features decreases. This obvious observation accounts for the discrepancy in the literature and suggests that the large inversion effect that was found for features that differ in shape is not a methodological artifact. These findings together with other data that are discussed are consistent with the idea that the shape of facial features and the spacing among them are integrated rather than dissociated in the holistic representation of faces.     

Repetition and Spacing Effects on True and False Recognition in the DRM Paradigm

Dubuisson, J.-B., Fiori, N. & Nicolas, S. (2012) Repetition and spacing effects on true and false recognition in the DRM paradigm. Scandinavian Journal of Psychology 53, 382-389. With the Deese-Roediger-McDermott (DRM) paradigm, the repetition effect on false memory had never been clarified. More importantly, the spacing effect on false memory was never directly investigated. So, we carried out two experiments to examine these effects on true and false recognition. In experiment 1, participants studied DRM lists which were presented one, three or five times. In experiment 2, we manipulated the repetition mode (massed vs. spaced with a short interval or a long interval) to explore the spacing effect. The results showed that true recognition increased monotonically with list repetition (experiment 1) and repetition spacing (experiment 2). The most striking finding was a similar spacing effect but no repetition effect on false recognition. Thus, these results were principally discussed in the light of the activation-monitoring framework.     

Voluntary attention and the spacing effect

Three experiments were done to test the hypothesis that the spacing effect results from a voluntary decision by the subject to pay little attention to the second presentation (P₂) of an item when it occurs shortly after the first (P¹)- In all three experiments, the spacing of repetitions was varied. In Experiment I, allocation of attention was manipulated by pairing P₂ of some pictures with a signal that indicated high payoff for later retention. In Experiment II, attention was controlled more directly by requiring the subject, in one condition, to recite words aloud. In both experiments, the dependent variable was judged frequency. In neither experiment did the effect of the attention manipulation interact with that of the spacing of repetitions. In Experiment III, the number of eye fixations given a picture was taken to be a measure of attention. The number of fixations dropped from P₁ to P₂ to P₃, but was unaffected by the spacing of repetitions. The experiments provide no support for a voluntary attention explanation of the spacing effect.     

Distributed and massed practice: from laboratory to classroom

The benefit to memory of spacing presentations of material is well established but lacks an adequate explanation and is rarely applied in education. This paper presents three experiments that examined the spacing effect and its application to education. Experiment 1 demonstrated that spacing repeated presentations of items is equally beneficial to memory for a wide range of ages, contrary to some theories. Experiment 2 introduced ‘clustered’ presentations as a more relevant control than massed, reflecting the fact that massed presentation of material is uncommon in education. The scheduling of clustered presentations was intermediate between massed and distributed, yet recall was no different than for massed. Experiment 3, a classroom‐based study, demonstrated the benefit of distributed over clustered teaching of reading through modification of the scheduling of everyday lessons. Thus, the effectiveness of teaching may be improved by increasing the degree to which lessons are distributed. Copyright © 2004 John Wiley & Sons, Ltd.     

Examining the lag effect under incidental encoding: Contributions of semantic priming and reminding

Memory is better when repeated learning events are spaced than when they are massed (spacing effect), as well as when material is processed semantically than when it is processed graphemically (levels-of-processing effect). Examination of the relationship between levels of processing and spacing for both deeply and shallowly encoded items has shown a spacing effect for items processed deeply, but not shallowly. A semantic priming account of spacing was proposed to explain the interaction between levels of processing and spacing on memory. The current study manipulated levels of processing and the amount of spacing (lag) that occurred between repetitions of items that were incidentally encoded. Results from Experiments 1A and 1B revealed lag effects in test performance when items were deeply and shallowly encoded. Although these findings are inconsistent with a semantic priming account, they can be interpreted within a reminding account, which is explored in Experiment 2. Results from the second experiment indicate that bringing reminding under conscious control benefited items that were presented at a long lag but not at a shorter lag. Together, this study provides evidence that is difficult to accommodate with a semantic priming account of spacing and instead provides additional support for a reminding account suggesting that automatic and controlled processes may both underlie the reminding process.     

Spacing effects in cued-memory tasks for unfamiliar faces and nonwords

Memory for repeated items improves as the interval between repetitions in a list increases (the spacing effect). This study investigated the spacing effect in recognition memory and in a frequency judgment task for unfamiliar target faces that were repeated in the same or in a different pose during incidental learning. Changing the pose between prime and probe trials reduced perceptual repetition priming in a structural discrimination task and also reduced the spacing effect in a subsequent unexpected recognition memory task. Three further experiments confirmed that the spacing effect inrecognition memory (Experiments 2 and 4) or frequency judgment (Experiment 3) was reduced when the pose was changed between repeated presentations at study. Similarly, with nonwords as targets (Experiment 5), changing the font between repeated occurrences of targets at study removed the spacing effect in a subsequent unexpected recognition memory test. These results are interpreted to support the view that short-term perceptual repetition priming underlies the spacing effect in explicit cued-memory tasks for unfamiliar nonsense material.     

Are two spaces better than one? The effect of spacing following periods and commas during reading

The most recent edition of the American Psychological Association (APA) Manual states that two spaces should follow the punctuation at the end of a sentence. This is in contrast to the one-space requirement from previous editions. However, to date, there has been no empirical support for either convention. In the current study, participants performed (1) a typing task to assess spacing usage and (2) an eye-tracking experiment to assess the effect that punctuation spacing has on reading performance. Although comprehension was not affected by punctuation spacing, the eye movement record suggested that initial processing of the text was facilitated when periods were followed by two spaces, supporting the change made to the APA Manual. Individuals’ typing usage also influenced these effects such that those who use two spaces following a period showed the greatest overall facilitation from reading with two spaces.     

The spacing effect: Additions to the theoretical and empirical puzzles

Four studies examined the MP-DP effect (spacing effect) in four quite different situations: recognition of letters, verbal discrimination, short free recall lists, and recall of MP items presented twice, with an intervening interval inserted to produce forgetting. MP-DP differences were found in all studies. Of particular interest were three interactions. Subjects with a low criterion of responding in the letter study lost the MP-DP effect over a 30-sec delay, and subjects with a high criterion did not. A clear MP-DP effect, but no lag effect, was found only with unmixed verbal discrimination lists. In free recall, a sharp lag effect was shown for words presented three times but not for words presented twice. A forgetting interval inserted between the two occurrences of an MP item did not appreciably aid its recall. The results were found to pose severe problems for current theoretical ideas about the spacing effect.     

The mirror effect and the spacing effect

In the mirror effect, there are fewer false negatives (misses) and false positives (false alarms) for rare (low-frequency) words than for common (high-frequency) words. In the spacing effect, recognition accuracy is positively related to the interval (spacing or lag) between two presentations of an item. These effects are related in that they are both manifestations of a leapfrog effect (a weaker item jumps over a stronger item). They seem to be puzzles for traditional strength theory and at least some current global-matching models. A computational strength-based model (EICL) is proposed that incorporates excitation, inhibition, and a closed-loop learning algorithm. The model consists of three nonlinear coupled stochastic difference equations, one each for excitation (x), inhibition (y), and context (z). Strength is the algebraic sum (i.e., s = x − y + z). These equations are used to form a toy lexicon that serves as a basis for the experimental manipulations. The model can simulate the mirror effect forcedchoice inequalities and the spacing effect for single-item recognition, all parameters are random variables, and the same parameter values are used for both the mirror and the spacing effects. No parameter values varied with the independent variables (word frequency for the mirror effect, lag for the spacing effect), so the model, not the parameters, is doing the work.     

Effects of context variation, intracategory variation, and spacing on the free recall of pictures

Abstract.— Two experiments examined the effects of encoding variability on the free recall of pictures. In Expt. I, drawn objects were presented 3 times in different pictorial contexts (RV) or in the same contexts (RR). In Expt. II, repeated stimuli were 3 different specimens of the same object category (VR) or the same object presented 3 times (RR). Spacing of repetitions was varied from zero to 15, and a mixed-list design was used. Both RV and VR items tended to be recalled better than and prior to RR items. Recall of RR and of VR items increased with increasing spacing, but recall of RV items showed no spacing effect. In a second recall test, preceded by 4 min of "thinking about" the pictures, the only remaining effect of spacing or of context variation was a low recall of massed RR items. VR items were still recalled better than and prior to RR items. It is suggested that spacing, and variation of the external context of pictures, facilitate retrieval when the time and effort spent on recall is limited, by increasing the numberlvariety of potential recall cues stored together with item information.     

The exemplar interleaving effect in inductive learning: Moderation by the difficulty of category discriminations

Recent research demonstrates a spacing effect in inductive learning. Spacing different individual exemplars apart in time, rather than massing them together, aids in the learning of categories. Experiment 1 examined whether it is interleaving or temporal spacing that is critical to the spacing effect in the situation wherethe memory load is high, and the results favored interleaving. Experiment 2 examined the effect of the difficulty of the category discrimination on presentation style (massed vs. spaced) in inductive learning, and the results demonstrated that spacing (i.e., interleaving of exemplars from different categories) is advantageous for low-discriminabilty categories, whereas massing is more effective for high-discriminability categories. In contrast to these performance measures, massing was judged by participants to be more effective than spacing in both discriminability conditions, even when performance for low-discriminability categories showed the opposite.     

Avoidance of overlearning characterises the spacing effect

The spacing of a fixed amount of study time across multiple sessions usually increases subsequent test performance—a finding known as the spacing effect. In the spacing experiment reported here, subjects completed multiple learning trials, and each included a study phase and a test. Once a subject achieved a perfect test, the remaining learning trials within that session comprised what is known as overlearning. The number of these overlearning trials was reduced when learning trials were spaced across multiple sessions rather than massed in a single session. In addition, the degree to which spacing reduced overlearning predicted the size of the spacing effect, which is consistent with the possibility that spacing increases subsequent recall by reducing the occurrence of overlearning. By this account, overlearning is an inefficient use of study time, and the efficacy of spacing depends at least partly on the degree to which it reduces the occurrence of overlearning.     

Why does picture-plane inversion sometimes dissociate perception of features and spacing in faces, and sometimes not? Toward a new theory of holistic processing

Classically, it has been presumed that picture-plane inversion primarily reduces sensitivity to spacing/configural information in faces (distance between location of the major features) and has little effect on sensitivity to local feature information (e.g., eye shape or color). Here, we review 22 published studies relevant to this claim. Data show that the feature inversion effect varied substantially across studies as a function of the following factors: whether the feature change was shape only or included color/brightness, the number of faces in the stimulus set, and whether the feature was in facial context. For shape-only changes in facial context, feature inversion effects were as large as typical spacing inversion effects. Small feature inversion effects occurred only when a task could be efficiently solved by visual-processing areas outside whole-face coding. The results argue that holistic/configural processing for upright faces integrates exact feature shape and spacing between blobs. We describe two plausible approaches to this process.     

Configural face processing develops more slowly than featural face processing

Expertise in face processing takes many years to develop. To determine the contribution of different face-processing skills to this slow development, we altered a single face so as to create sets of faces designed to measure featural, configural, and contour processing. Within each set, faces differed only in the shape of the eyes and mouth (featural set), only in the spacing of the eyes and mouth (spacing set), or only in the shape of the external contour (contour set). We presented adults, and children aged 6, 8, and 10 years, with pairs of upright and inverted faces and instructed them to indicate whether the two faces were the same or different. Adults showed a larger inversion effect for the spacing set than for the featural and external contour sets, confirming that the spacing set taps configural processing. On the spacing set, all groups of children made more errors than adults. In contrast, on the external contour and featural sets, children at all ages were almost as accurate as adults, with no significant difference beginning at age 6 on the external contour set and beginning at age 10 on the featural set. Overall, the results indicate that adult expertise in configural processing is especially slow to develop.     

Spacing enhances the learning of natural concepts: an investigation of mechanisms,metacognition, and aging

In two experiments, we examined spacing effects on the learning of bird families and metacognitive assessments of such learning. Results revealed that spacing enhanced learning beyond massed study. These effects were increased by presenting birds in pairs so as to highlight differences among families during study (Experiment 1). Self-allocated study time provided evidence that more attention was paid during spaced than during massed study and resulted in no age differences in learning (Experiment 2). Metacognitive measures revealed sensitivity to the processing advantage of spaced study and to differences in classification difficulty across categories. No difference occurred in monitoring accuracy for young versus older adults. These findings provide evidence for discrimination- and attention-based accounts of the spacing effect in natural concept learning.     

Children's memory for complex autobiographical events: does spacing of repeated instances matter?

Often, when children testify in court they do so as victims of a repeated offence and must report details of an instance of the offence. One factor that may influence children's ability to succeed in this task concerns the temporal distance between presentations of the repeated event. Indeed, there is a substantial amount of literature on the "spacing effect" that suggests this may be the case. In the current research, we examined the effect of temporal spacing on memory reports for complex autobiographical events. Children participated in one or four play sessions presented at different intervals. Later, children were suggestively questioned, and then participated in a memory test. Superior recall of distributed events (a spacing effect) was found when the delay to test was 1 day (Experiment 1) but there was little evidence for a spacing effect when the delay was 1 week (Experiment 2). Implications for understanding children's recall of repeated autobiographical events are discussed.