Children's working-memory processes: a response-timing analysis

Recall response durations were used to clarify processing in working-memory tasks. Experiment 1 examined children's performance in reading span, a task in which sentences were processed and the final word of each sentence was retained for subsequent recall. Experiment 2 examined the development of listening-, counting-, and digit-span task performance. Responses were much longer in the reading-and listening-span tasks than in the other span tasks, suggesting that participants in sentence-based span tasks take time to retrieve the semantic or linguistic structure as cues to recall of the sentence-final words. Response durations in working-memory tasks helped to predict academic skill and achievement, largely separate from the contributions of the memory spans themselves. Response durations thus are important in the interpretation of span task performance.     

Short-term memory and working memory as indices of children's cognitive skills

In the current literature, empirical and conceptual distinctions have been drawn between a more or less passive short-term memory (STM) system and a more dynamic working memory (WM) system. Distinct tasks have been developed to measure their capacity and research has generally shown that, for adults, WM, and not STM, is a reliable predictor of general cognitive ability. However, the locus of the differences between the tasks has received little attention. We present data from children concerning measures of matrices reasoning ability, reading, and numerical skill along with forward and backward order serial recall of WM, STM, and STM with articulatory suppression tasks. As indices of children's cognitive skills, STM and WM are shown to be rather similar in terms of memory per se. Neither the opportunity for rehearsal nor task complexity provides satisfactory explanations for differences between memory tests.     

Analyzing human random generation behavior: A review of methods used and a computer program for describing performance

In this paper, we consider the different methods that have been developed to quantify random generation behavior and incorporate these measurement scales into a Windows95 computer program called RgCalc. RgCalc analyzes the quality of human attempts at random generation and can provide computer-generated, pseudorandom sequences for comparison. The program is designed to be appropriate for the analysis of various types of random generation situations employed in the psychological literature. The different algorithms for the evaluation of a dataset are detailed and an outline of the program is described. Performance measures are available for assessing various aspects of the response distribution, the sequencing of pairs, the ordinal relationships between sets of items, and the tendency to repeat alternatives over different lengths. A factor analysis is used to illustrate the multiple dimensions underlying human randomization processes.     

Is there a Relationship between Task Demand and Storage Space in Tests of Working Memory Capacity?

This paper considers working memory capacity, critically examining the hypothesis that counting span (the ability to count arrays of objects and store count totals) reflects a trade-off in resources available for processing and short-term storage. Previous evidence interpreted as favouring this hypothesis has confounded task difficulty with counting time. Experiment 1 validated a manipulation of the attentional demands of counting in which target objects were differentiated from non-targets by either a single feature (colour) or a feature conjunction (a combination of line orientations). The results confirmed that the two presentations involved qualitatively different attentional loads. Experiment 2 used these displays to compare counting span for children aged 6 to 11, both with and without an adjustment of target numerosity to control for differences in processing time. At all ages, span was lower when counting took longer, but there was no difference between feature and conjunction arrays once counting time was accounted for. These results argue against a resource trade-off interpretation of counting span. Rather, they support a hypothesis of resource-switching among children, implying that counting span acts as a measure of time-based forgetting.     

Random number generation and working memory

We demonstrate the close relationship that exists between random sequence generation and working memory functioning. We clarify the nature of this link by examining the impact of concurrent requirements for random sequence response quality. Experiments 1A and 1B show that marking specific response choices for differential treatment, either by requiring an ancillary behaviour or by suppressing these choices from output, impairs overall sequence quality. Contrasting with previous findings, these distinct concurrent tasks have comparable effects. We show that disruption is found only when concurrent demand is high. Experiment 2 demonstrates that increasing the dynamic working memory load by requiring the ancillary response to change during the task leads to additional disruption of randomisation. The results extend and refine our understanding of the contribution of active maintenance of representations in random generation.     

On the nature of the relationship between processing activity and item retention in children

The concept of working memory emphasizes the interrelationship between the transient retention of information and concurrent processing activity. Three experiments address this relationship in children between 8 and 17 years of age by examining forgetting when a processing task is interpolated between presentation and recall of the memory items. Unlike previous studies, delivery of interpolated stimuli was under computer control and responses to these stimuli were timed. There were consistent effects of the duration of the interpolated task, but no effects of either its difficulty or similarity to memory material and no qualitative developmental differences in task performance. The absence of an effect of difficulty provides no support for models of working memory in which limited capacity is shared between the dual functions of processing and storage, but is compatible with an alternative "task switching" account. However, task switching did not explain developmental differences in recall. Other aspects of the results suggest that there can be interactions between processing and storage but it is argued that these cannot be straightforwardly explained in terms of either task switching or resource sharing.     

The endurance of children's working memory: a recall time analysis

We analyze the timing of recall as a source of information about children’s performance in complex working memory tasks. A group of 8-year-olds performed a traditional operation span task in which sequence length increased across trials and an operation period task in which processing requirements were extended across trials of constant sequence length. Interword pauses were longer than are commonly found in immediate serial recall tasks yet shorter than for reading span. These pauses increased with the demands of recall, decreased across the output sequence, and were to some extent predictive of scholastic ability. Overall, timing data illustrate that recall in working memory tasks involves subtle processes of item access rather than simple readout of information from an immediate store.     

Synergies between processing and memory in children’s reading span

Previous research has established the relevance of working memory for cognitive development. Yet the factors responsible for shaping performance in the complex span tasks used to assess working memory capacity are not fully understood. We report a study of reading span in 7‐ to 11‐year‐old children that addresses several contemporary theoretical issues. We demonstrate that both the timing and the accuracy of recall are affected by the presence or absence of a semantic connection between the processing requirement and the memoranda. Evidence that there can be synergies between processing and memory argues against the view that complex span simply measures the competition between these activities. We also demonstrate a consistent relationship between the rate of completing processing operations (sentence reading) and recall accuracy. At the same time, the shape and strength of this function varies with the task configuration. Taken together, these results demonstrate the potential for reconstructive influences to shape working memory performance among children.     

The facilitatory effect of negative feedback on the emergence of analogical reasoning abilities

This paper focuses on the development of analogical reasoning abilities in 5‐ and 6‐year‐old children. Our particular interest relates to the way in which analogizing is influenced by the provision of task‐based feedback coupled with a self‐explanation requirement. Both feedback and self‐explanation provide children with opportunities to engage in self‐reflective thinking about the process of analogical reasoning. To examine the role of such metacognitive factors in analogical strategy development the reported study combined a proportional analogy paradigm with a small‐scale microgenetic approach involving multiple testing sessions over a restricted time period. The key manipulation involved exposing participants either to the correct or incorrect analogy completions of another reasoner that they were then asked to explain. The data revealed that the development of an effective analogizing strategy embodying a ‘relational shift’ from superficial to relational responding was modulated by the feedback condition that the child was placed in, with a negative feedback intervention providing the greatest developmental benefit. We suggest that the value of negative feedback for the acquisition of analogical reasoning abilities derives from the way in which a self‐reflective analysis of the reasons for erroneous responses sensitizes the child to a deeper understanding of how to make effective relational mappings.     

Discounting of food and water in rats shows trait- and state-like characteristics

Delay discounting is the loss in value of an outcome as a function of its delay. The present study focused on examining a trait-like characteristic of delay discounting in a preclinical animal model. Specifically, we were interested in whether there was a positive relation between discounting of 2 different outcomes in rats. That is, would rats that discount delayed food steeply also discount delayed water steeply? In addition, we examined how session-to-session variability in discounting could be attributed to differences between subjects (trait variability) and to differences within subjects (state variability). Finally, we measured discounting from early- to mid-adulthood, allowing us to examine changes in discounting as a function of age. Overall, we found a moderate, positive correlation between discounting of food and discounting of water in rats, providing further evidence that the relative consistency with which individuals discount different outcomes is a trait-like characteristic. In addition, we found a high degree of within-subject variability in discounting, indicating strong state-like differences from session to session. Finally, overall, discounting decreased as a function of age; however, individual-subject data showed variability in how discounting changed across time. Overall, our results show that differences in delay discounting between individuals reflect variability in both trait- and state-like characteristics.