A comparison of serial order short-term memory effects across verbal and musical domains

Recent studies suggest that the mechanisms involved in the short-term retention of serial order information may be shared across short-term memory (STM) domains such as verbal and visuospatial STM. Given the intrinsic sequential organization of musical material, the study of STM for musical information may be particularly informative about serial order retention processes and their domain-generality. The present experiment examined serial order STM for verbal and musical sequences in participants with no advanced musical expertise and experienced musicians. Serial order STM for verbal information was assessed via a serial order reconstruction task for digit sequences. In the musical domain, serial order STM was assessed using a novel melodic sequence reconstruction task maximizing the retention of tone order information. We observed that performance for the verbal and musical tasks was characterized by sequence length as well as primacy and recency effects. Serial order errors in both tasks were characterized by similar transposition gradients and ratios of fill-in:infill errors. These effects were observed for both participant groups, although the transposition gradients and ratios of fill-in:infill errors showed additional specificities for musician participants in the musical task. The data support domain-general serial order STM effects but also suggest the existence of additional domain-specific effects. Implications for models of serial order STM in verbal and musical domains are discussed.     

Secondary-task effects on sequence learning

With a repeated sequence of stimuli, performance in a serial reaction-time task improves more than with a random sequence. The difference has been taken as a measure of implicit sequence learning. Implicit sequence learning is impaired when a secondary task is added to the serial RT task. In the first experiment, secondary-task effects on different types of sequences were studied to test the hypothesis that the learning of unique sequences (where each sequence element has a unique relation to the following one) is not impaired by the secondary task, while the learning of ambiguous sequences is. The sequences were random up to a certain order of sequential dependencies, where they became deterministic. Contrary to the hypothesis, secondary-task effects on the learning of unique sequences were as strong or stronger than such effects on the learning of ambiguous sequences. In the second experiment a hybrid sequence (with unique as well as ambiguous transitions) was used with different secondary tasks. A visuo-spatial and a verbal memory task did not interfere with the learning of the sequence, but interference was observed with an auditory go/no-go task in which high- and low-pitched tones were presented after each manual response and a foot pedal had to be pressed in response to high-pitched tones. Thus, interference seems to be specific to certain secondary tasks and may be related to memory processes (but most likely not to visuo-spatial and verbal memory) or to the organization of sequences, consistent with previous suggestions.     

Spontaneous categorizers retain more than spontaneous alphabetizers

Immediate and delayed free recall of unstructured verbal materials were assessed for alphabetizers and categorizers after varying study times. Alphabetizers and categorizers did not differ in immediate recall, but retention following a 6-day interval was consistently higher for categorizers than for alphabetizers. Both immediate and delayed recall increased with study time, which did not interact with learning strategy. In the next experiment alphabetizers and categorizers learned two lists, the second of which was categorically structured or unstructured. No retroactive interference on first-list recall was produced by the learning of the structured list, but the learning of the unstructured list produced retroactive interference for the alphabetizers only. It was suggested that, although both alphabetizers and categorizers probably use their respective strategies for other verbal tasks, the categoric strategy should create less interference because specific 'categories are rarely encountered in successive tasks.     

Order of a 'uniform random' presentation on contextual interference in a serial tracking task

The purpose of the present study was to examine the effect of order of a 'uniform random' presentation on contextual interference in a serial tracking task. Subjects (N=48) were randomly assigned to either a random condition or a blocked condition in the acquisition phase, in which they learned three patterns of serial tracking tasks. Subjects performed retention and transfer trials either in a blocked or a 'uniform random' order. Analysis indicated, in comparisons of performance among conditions, 'uniform random' presentation in the acquisition phase did not improve learning in retention and transfer phases. The results are discussed with regard to both theoretical significance to contextual interference and the nature of 'uniform random' presentation.     

Discrimination learning as a function of differences in materials: A proposed explanation

The present study affords an explanation for the consistent, but not always statistically significant, pattern showing superior verbal discrimination learning performance for low- as compared to high-frequency words. In a frequency judgment task, it was found that relative to high-frequency words, low-frequency words for which Ss (sixth graders) knew the meanings produced apparent frequency measures consistent with superior verbal discrimination learning, while low-frequency words that were unknown to the children did not. These results, taken together with those based on comparisons of pictures and high-frequency words, lend themselves to a modified Weber’s law interpretation of stimulus material differences in discrimination learning.     

Hebb learning, verbal short-term memory, and the acquisition of phonological forms in children

Recent work using the Hebb effect as a marker for implicit long-term acquisition of serial order has demonstrated a functional equivalence across verbal and visuospatial short-term memory. The current study extends this observation to a sample of five- to six-year-olds using verbal and spatial immediate serial recall and also correlates the magnitude of Hebb learning with explicit measures of word and nonword paired-associate learning. Comparable Hebb effects were observed in both domains, but only nonword learning was significantly related to the magnitude of Hebb learning. Nonword learning was also independently related to individuals' general level of verbal serial recall. This suggests that vocabulary acquisition depends on both a domain-specific short-term memory system and a domain-general process of learning through repetition.     

Developmental trends in distractibility: Is absolute or proportional decrement the appropriate measure of interference?

Since baseline performance varies with age, diminished interference effects found with increasing age do not provide evidence for a developmental trend in distractibility unless their relationship to baseline performance is known. In the present study, baseline difficulty was varied in two speeded classification experiments to investigate whether interference effects due to irrelevant information could best be characterized by absolute or proportional decrement models. In Experiment 1, first graders, third graders, and adults sorted cards on the basis of square size, both in the presence and absence of extraneous stimulus information. In Experiment 2, first graders and adults sorted cards on the basis of the density of a regular array of dots and two kinds of irrelevant information were used. Robust interference effects were found which declined with age. Manipulating discriminability of the relevant stimulus dimension resulted in large changes in sorting time, but interference effects did not vary with baseline difficulty. These results were interpreted as strongly supporting both an absolute decrement model and a developmental trend in distractibility.     

Verbal Learning Strategies of Adolescents and Adults with the Syndrome of Nonverbal Learning Disabilities

Abstract

Although many psychometric studies of individuals with the syndrome of nonverbal learning disabilities (NLD) have been conducted, one relatively neglected area has been the study of their performance on explicit verbal memory measures. We examined the performance of adolescents and adults with NLD on the California Verbal Learning Test, a measure allowing analysis of self-initiated learning strategies, and compared their performance to age- and Full Scale IQ-matched verbal learning-disabled (VLD) controls. Mean performance of the NLD sample on the semantic clustering index fell one standard deviation below the normative mean, whereas their serial clustering score was within normal limits. Additionally, the serial clustering score for our NLD sample was significantly greater than their semantic clustering score, suggesting that these individuals are more likely to spontaneously employ serial verbal learning strategies as opposed to those that are semantically driven. This difference in serial versus semantic clustering scores was not seen in our VLD controls, who performed equally well, and within normal limits, on both indices.     

Effects of contextual interference on learning technical sports skills.

The effects of contextual interference on learning skills of volleyball (volley, bump, serve) are influenced by the scheduling of actual practice sessions: the activities can be proposed in a repetitive practice schedule (blocked practice) by continuously repeating the same task (low interference) or in random practice schedules by performing more tasks or variations of one same activity (high interference). High contextual interference, even though causing immediate limited performance, leads to superior performance on retention and transfer tests. Four experimental groups (13 students each) were placed in conditions of random, blocked, serial, and serial with high interference practice for 8 meetings (2 tests and 6 practice). Analysis yielded significant differences among the groups on a transfer test (long transfer) for the serve, so results in this instructional setting are partially in line with those generally found in laboratory experiments.     

Learning at Workstations in the Zoo: A Controlled Evaluation of Cognitive and Affective Outcomes

ABSTRACT

This study aimed to test the cognitive and affective benefits gained through the provision of educational materials at workstations in the Wilhelma Zoo in Stuttgart, Germany. Structured learning materials were developed for use with visiting school groups. The materials focused on the adaptations of 6 selected groups of bird species and were organized as a self-guided learning environment (workstations). The value of the materials was assessed in terms of cognitive (learning and retention) and emotional (interest, well-being, boredom, anxiety, contentedness) variables. The authors measured prior knowledge (1 week before the zoo visit), learning effect (1 week after the visit), and retention (8 to 9 weeks later). A total of 103 students (6th graders aged between 11–12 years) participated in the study, 77 receiving a treatment about adaptations in bird species and 26 receiving a treatment about reptiles which served as a control. Students had similar prior knowledge, but 1 week later students receiving the bird unit scored significantly better and this persisted into retention. Girls achieved higher scores than boys, both 1 week and 8 to 9 weeks after the visit. Surprisingly, students in the control group reported higher interest, well-being and contentedness, and lower boredom than those in the treatment group.     

Serial position memory in the visual—spatial domain: Reconstructing sequences of unfamiliar faces

In two studies we presented pictures of unfamiliar faces one at a time, then presented the complete set at test and asked for serial reconstruction of the order of presentation. Serial position functions were similar to those found with verbal materials, with considerable primacy and one item recency, position errors that were mainly to the adjacent serial position, a visual similarity effect, and effects of articulatory suppression that did not interact with the serial position effect or with the similarity effect. Serial position effects were found when faces had been seen for as little as 300 ms and after a 6-s retention interval filled with articulatory suppression. Serial position effects found with unfamiliar faces are not based on verbal encoding strategies, and important elements of serial memory may be general across modalities.     

Do cognitive factors in motor performance become nonfunctional with practice?

Cognitive factors in motor behavior were defined as verbal and imagery mediators for a discrete, sequential motor task. The question was asked whether these mediators become nonfunctional with extended practice. Non-motor interference training was given in inappropriate verbal and imagery mediation. If cognitive factors in the motor task involve verbal an/or imagery dimensions, and they dominate early in learning, then the non motor interference training should produce relatively large negative transfer effects in the motor performance early in learning and little or no such effects late in learning. The results did not conform to expectation; small negative transfer effects were found both early and late in learning. The discussion considered several possible reason for the outcome: the motor task was dominated by visual and proprioception factors rather than cognitive ones, the method of delivering knowledge of results may have minimized cognitive factors, or the hypothesis is wrong.     

Evidence for modality-independent order coding in working memory

The aim of the present study was to investigate the representation of serial order in working memory, more specifically whether serial order is coded by means of a modality-dependent or a modality-independent order code. This was investigated by means of a series of four experiments based on a dual-task methodology in which one short-term memory task was embedded between the presentation and recall of another short-term memory task. Two aspects were varied in these memory tasks—namely, the modality of the stimulus materials (verbal or visuo-spatial) and the presence of an order component in the task (an order or an item memory task). The results of this study showed impaired primary-task recognition performance when both the primary and the embedded task included an order component, irrespective of the modality of the stimulus materials. If one or both of the tasks did not contain an order component, less interference was found. The results of this study support the existence of a modality-independent order code.     

On knowing how well one is remembering: The persistence of strategy use during transfer

A potential cause for children's failure to transfer learning strategies was explored in the present study. A self-monitoring process was suggested to be essential for evaluating one's own level of performance and the effectiveness of various mnemonic strategies. Matched on free recall scores in this study's first sort-and-recall phase, first, third, and fifth graders (ages 7, 9, and 11 years, respectively) were assigned to one of three treatment groups or a control group. During Phase II, the treatment groups received instruction in sorting pictures according to semantic similarities in preparation for future recall. In addition, Groups 3 and 4 later received feedback indicating their Phase II improvement in performance. A cause-and-effect relationship between strategy use and enhanced recall was further suggested to Group 4. Among third graders, only those provided with feedback and strategy instruction continued to rely upon the input organization strategy when faced with transfer tasks in Phase III. Both enhanced recall and improved sorting styles were observed for these subjects in Phase III. Some first graders also showed improved sorting styles and improved recall following feedback, while fifth graders showed enhanced recall even without experimenter-provided feedback. Subject's responses to a metamemory interview provided additional support for the hypothesis that the self-monitoring of memory performance is more likely to be part of fifth graders' (than first graders') memory abilities.     

Evidence for modality-independent order coding in working memory

The aim of the present study was to investigate the representation of serial order in working memory, more specifically whether serial order is coded by means of a modality-dependent or a modality-independent order code. This was investigated by means of a series of four experiments based on a dual-task methodology in which one short-term memory task was embedded between the presentation and recall of another short-term memory task. Two aspects were varied in these memory tasks--namely, the modality of the stimulus materials (verbal or visuo-spatial) and the presence of an order component in the task (an order or an item memory task). The results of this study showed impaired primary-task recognition performance when both the primary and the embedded task included an order component, irrespective of the modality of the stimulus materials. If one or both of the tasks did not contain an order component, less interference was found. The results of this study support the existence of a modality-independent order code.     

Facilitation of retention by white noise.

Second and fifth grade subjects were given three verbal tasks: serial, free recall, or paired-associate learning. Retention tests were administered immediately after the acquisition phase or following a long delay. Half the subjects were exposed to a 2-min period of bursts of white noise (arousal) immediately prior to the retention test. The finding of primary interest was that white noise produced substantial improvement in performance relative to a control condition. This effect may be more pronounced for long-term memory than for short-term memory. Although older children exhibited better long-term memory than younger subjects, no interaction of age with arousal condition was observed.     

Age differences in learning serial patterns: direct versus indirect measures

Adult age differences in learning and retention of a nonverbal sequence were examined using the serial reaction-time task of Nissen and Bullemer (1987), with 20 younger and 20 older Ss. An asterisk appeared in one of 4 spatial locations, and the Ss responded with a corresponding key press. The first 4 blocks each contained 10 repetitions of a 10- or 16-element spatial sequence, and the 5th block contained a random sequence. The difference between response time on Blocks 5 and 4 served as an indirect measure of pattern learning. The direct measure was accuracy in a final generation block in which the Ss predicted which location would appear next. Results were similar to those with verbal materials; the indirect measure revealed age similarity for patterns of both lengths, but the direct measure yielded age differences favoring the young. For both ages and types of measures, the long patterns led to poorer learning than did the short patterns.     

Verbal rehearsal and selective attention in children with learning disabilities: A developmental lag

To investigate the development of verbal rehearsal strategies and selective attention in learning disabled children, Hagen's Central-Incidental task was administered to younger learning disabled (M CA = 8.68 years) and normal (M CA = 8.62 years) boys in Experiment 1 and to intermediate (M CA = 10.18 years) and older (M CA = 13.48 years) learning disabled boys in Experiment 2. Also, in Experiment 2, an experimentally induced verbal rehearsal condition was included to determine its effects on serial recall and selective attention performance. In Experiment 1, the serial postion curve of the normals revealed both a primacy and a recency effect, whereas that of the learning disabled revealed a recency effect only. In Experiment 2, both the intermediate and the older learning disabled exhibited both primacy and recency effects under both standard and rehearsal conditions. A developmental analysis of central recall for the three learning disabled groups revealed constant age-related increases in overall central recall and in primacy recall. That the normals recalled more central, but not more incidental, information than the learning disabled in Experiment 1 suggests that the learning disabled are deficient in selective attention. Correlational findings suggest that the selective attention of the learning disabled improves with age. The results were interpreted as support for the hypothesis of a developmental lag in the learning disabled population.     

Specificity in practice benefits learning in novice models and variability in demonstration benefits observational practice

Considerable research has shown that both demonstration and verbal instruction can facilitate learning of a motor task in inexperienced individuals. In the current study, verbal instructions were used as a means to reduce the discovery learning process and control the amount of trial-to-trial variability in demonstrations. The task required models to learn to trace a pair of circles with a 90°-relative phase pattern between the arms. Verbal instructions directed one group of models toward a single strategy, and this group improved at a faster rate and performed better in a 24-h retention test compared to a group of models in a discovery learning context. The discovery models utilized multiple strategies throughout the practice. Each model was watched for 2 days by an observer, who was instructed that they would have to produce the 90°-relative phase pattern on day 3. Observers, who watched the discovery models, performed better than those who watched the single strategy models. The results support two primary conclusions. First, trial-to-trial variability associated with strategy selection processes in a model benefits an observer by facilitating perceptual discrimination processes that may play a key role in action generation. Second, verbal instructions that reduce discovery learning during physical practice benefit acquisition and retention performance when the task has multiple strategies wherein no one strategy guarantees the best performance outcome.     

Conditions affecting retention test performance: A developmental study

Developmental studies of retention have yielded remarkably diverse results: however, it is widely assumed that retention ability increases with age. This study examined this assumption by investigating some of the conditions that might affect retention test performance in third graders and tenth graders. The most important results were the absence of age differences in proportionalized short-term retention, despite substantial differences in the number of items learned, and significant age differences in long-term retention only between groups that had received a different number of learning trials. These and other results suggest that age differences in retention test performance occur only when age is confounded with degree of learning. In short, there do not appear to be any age differences in retention per se.