The effectiveness of feedback in multiple-cue probability learning

How effective are different types of feedback in helping us to learn multiple contingencies? This article attempts to resolve a paradox whereby, in comparison to simple outcome feedback, additional feedback either fails to enhance or is actually detrimental to performance in nonmetric multiple-cue probability learning (MCPL), while in contrast the majority of studies of metric MCPL reveal improvements at least with some forms of feedback. In three experiments we demonstrate that if feedback assists participants to infer cue polarity then it can in fact be effective in nonmetric MCPL. Participants appeared to use cue polarity information to adopt a linear judgement strategy, even though the environment was nonlinear. The results reconcile the paradoxical contrast between metric and nonmetric MCPL and support previous findings of people's tendency to assume linearity and additivity in probabilistic cue learning.     

The role of working memory capacity in multiple-cue probability learning

Multiple-cue probability learning (MCPL) involves learning to predict a criterion when outcome feedback is provided for multiple cues. A great deal of research suggests that working memory capacity (WMC) is involved in a wide range of tasks that draw on higher level cognitive processes. In three experiments, we examined the role of WMC in MCPL by introducing measures of working memory capacity, as well as other task manipulations. While individual differences in WMC positively predicted performance in some kinds of multiple-cue tasks, performance on other tasks was entirely unrelated to these differences. Performance on tasks that contained negative cues was correlated with working memory capacity, as well as measures of explicit knowledge obtained in the learning process. When the relevant cues predicted positively, however, WMC became irrelevant. The results are discussed in terms of controlled and automatic processes in learning and judgement.     

An investigation of the role of some person and situation variables in multiple cue probability learning

Making decisions using judgements of multiple non-deterministic indicators is an important task, both in everyday and professional life. Learning of such decision making has often been studied as the mapping of stimuli (cues) to an environmental variable (criterion); however, little attention has been paid to the effects of situation-by-person interactions on this learning. Accordingly, we manipulated cue and feedback presentation mode (graphic or numeric) and task difficulty, and measured individual differences in working memory capacity (WMC). We predicted that graphic presentation, fewer cues, and elevated WMC would facilitate learning, and that person and task characteristics would interact such that presentation mode compatible with the decision maker's cognitive capability (enhanced visual or verbal WMC) would assist learning, particularly for more difficult tasks. We found our predicted main effects, but no significant interactions, except that those with greater WMC benefited to a larger extent with graphic than with numeric presentation, regardless of which type of working memory was enhanced or number of cues. Our findings suggest that the conclusions of past research based predominantly on tasks using numeric presentation need to be reevaluated and cast light on how working memory helps us learn multiple cue–criterion relationships, with implications for dual-process theories of cognition.     

Differences between probability and frequency judgments: The role of individual differences in working memory capacity

Most theories of probability judgment assume that judgments are made by comparing the strength of a focal hypothesis relative to the strength of alternative hypotheses. In contrast, research suggests that frequency judgments are assessed using a non-comparative process; the strength of the focal hypothesis is assessed without comparing it to the strength of alternative hypotheses. We tested this distinction between probability and frequency judgments using the alternative outcomes paradigm (Windschitl, Young, & Jenson, 2002). Assuming that judgments of probability (but not judgments of frequency) entail comparing the focal hypothesis with alternative hypotheses, we hypothesized that probability judgments would be sensitive to the distribution of the alternative hypotheses and would be negatively correlated with individual differences in working memory (WM) capacity. In contrast, frequency judgments should be unrelated to the distribution of the alternatives and uncorrelated with WM-capacity. Results supported the hypotheses.     

Happiness increases verbal and spatial working memory capacity where sadness does not: Emotion,working memory and executive control

The effects of emotion on working memory and executive control are often studied in isolation. Positive mood enhances verbal and impairs spatial working memory, whereas negative mood enhances spatial and impairs verbal working memory. Moreover, positive mood enhances executive control, whereas negative mood has little influence. We examined how emotion influences verbal and spatial working memory capacity, which requires executive control to coordinate between holding information in working memory and completing a secondary task. We predicted that positive mood would improve both verbal and spatial working memory capacity because of its influence on executive control. Positive, negative and neutral moods were induced followed by completing a verbal (Experiment 1) or spatial (Experiment 2) working memory operation span task to assess working memory capacity. Positive mood enhanced working memory capacity irrespective of the working memory domain, whereas negative mood had no influence on performance. Thus, positive mood was more successful holding information in working memory while processing task-irrelevant information, suggesting that the influence mood has on executive control supersedes the independent effects mood has on domain-specific working memory.     

The role of working memory capacity in autobiographical retrieval: Individual differences in strategic search

Remembering previous experiences from one's personal past is a principal component of psychological well-being, personality, sense of self, decision making, and planning for the future. In the current study the ability to search for autobiographical information in memory was examined by having college students recall their Facebook friends. Individual differences in working memory capacity manifested itself in the search of autobiographical memory by way of the total number of friends remembered, the number of clusters of friends, size of clusters, and the speed with which participants could output their friends' names. Although working memory capacity was related to the ability to search autobiographical memory, participants did not differ in the manner in which they approached the search and used contextual cues to help query their memories. These results corroborate recent theorising, which suggests that working memory is a necessary component of self-generating contextual cues to strategically search memory for autobiographical information.     

The relationship between working memory capacity and cortical activity during performance of a novel motor task

ObjectivesThis study assessed whether individual differences in working memory capacity influenced verbal-analytical processes when performing a novel motor skill.DesignParticipants performed a tennis-hitting task in two conditions: no pressure and high-pressure.MethodsEighteen young adults participated in the study. EEG coherence between the T3-F3 and T4-F4 regions in the Beta1 and Alpha2 frequencies was recorded during performance in each condition. Verbal and visuo-spatial working memory capacity were assessed using the Automated Working Memory Assessment.ResultsNo differences were found between the two conditions for hitting performance and EEG activity. However, across both conditions, verbal and visuo-spatial working memory were significant predictors of EEG coherence between the T3-F3 and T4-F4 regions in the Beta1 and Alpha2 frequencies. Larger verbal working memory capacity was associated with greater coherence while the opposite trend was observed for visuo-spatial working memory capacity.ConclusionsThese results indicate that larger verbal working memory capacity is associated with a greater tendency to use explicit processes during motor performance, whereas larger visuo-spatial working memory capacity is associated more with implicit processes. The findings are discussed with relevance to the theory of implicit motor learning.     

The influence of temporal resolution power and working memory capacity on psychometric intelligence

According to the temporal resolution power (TRP) hypothesis, higher TRP as reflected by better performance on psychophysical timing tasks accounts for faster speed of information processing and increased efficiency of information processing leading to better performance on tests of psychometric intelligence. An alternative explanation of individual differences in psychometric intelligence highlights individual differences in working memory (WM) capacity which has been found to be closely associated with psychometric intelligence. A latent variable approach was applied on the data of 200 participants ranging in age from 18 to 30 years and spanning a large range of levels of psychometric intelligence. Functional relationships were examined among TRP, WM capacity, as well as reasoning and speed of processing as two important aspects of psychometric intelligence. As predicted by the TRP hypothesis, the relation between TRP and psychometric intelligence was mediated by WM capacity supporting the view that higher TRP leads to better coordinated mental operations which, in turn, result in higher psychometric intelligence. The results are discussed against the background that WM capacity and psychometric reasoning are hardly dissociable from each other and that the specific factors limiting WM capacity and accounting for the mediation effect need to be identified in future research.     

Individual differences in category learning: sometimes less working memory capacity is better than more

We examined whether individual differences in working memory influence the facility with which individuals learn new categories. Participants learned two different types of category structures: rule-based and information-integration. Successful learning of the former category structure is thought to be based on explicit hypothesis testing that relies heavily on working memory. Successful learning of the latter category structure is believed to be driven by procedural learning processes that operate largely outside of conscious control. Consistent with a widespread literature touting the positive benefits of working memory and attentional control, the higher one’s working memory, the fewer trials one took to learn rule-based categories. The opposite occurred for information-integration categories - the lower one’s working memory, the fewer trials one took to learn this category structure. Thus, the positive relation commonly seen between individual differences in working memory and performance can not only be absent, but reversed. As such, a comprehensive understanding of skill learning - and category learning in particular - requires considering the demands of the tasks being performed and the cognitive abilities of the performer.     

Depressive thoughts limit working memory capacity in dysphoria

Dysphoria is associated with persistence of attention on mood-congruent information. Longer time attending to mood-congruent information for dysphoric individuals (DIs) detracts from goal-relevant information processing and should reduce working memory (WM) capacity. Study 1 showed that DIs and non-DIs have similar WM capacities. Study 2 embedded depressive information into a WM task. Compared to non-DIs, DIs showed significantly reduced WM capacity for goal-relevant information in this task. Study 3 replicated results from Studies 1 and 2, and further showed that DIs had a significantly greater association between processing speed and recall on the depressively modified WM task compared to non-DIs. The presence of inter-task depressive information leads to DI-related decreased WM capacity. Results suggest dysphoria-related WM capacity deficits when depressive thoughts are present. WM capacity deficits in the presence of depressive thoughts are a plausible mechanism to explain day-to-day memory and concentration difficulties associated with depressed mood.     

A Bayesian hierarchical model for the measurement of working memory capacity

Working memory is the memory system that allows for conscious storage and manipulation of information. The capacity of working memory is extremely limited. Measurements of this limit, and what affects it, are critical to understanding working memory. Cowan (2001) and Pashler (1988) suggested applying multinomial tree models to data from change detection paradigms in order to estimate working memory capacity. Both Pashler and Cowan suggested simple formulas for estimating capacity with these models. However, in many cases, these simple formulas are inadequate, and may lead to inefficient or biased estimation of working memory capacity. I propose a Bayesian hierarchical alternative to the Pashler and Cowan formulas, and show that the hierarchical model outperforms the traditional formulas. The models are easy to use and appropriate for a wide range of experimental designs. An easy-to-use graphical user interface for fitting the hierarchical model to data is available.     

The phenotypic and genotypic relation between working memory speed and capacity

This study examined the phenotypic and genotypic relationship between working memory speed (WMS) and working memory capacity (WMC) in 12-year-old twins and their siblings (N = 409). To asses WMS all children performed a reaction time task with three memory loads from which a basic mental speed measure and the derived slope were used. WMC was measured with two subtests of the WISC-R, namely Arithmetic and Digit Span. The phenotypic correlations among the WMS and WMC indices were around − 0.30. Heritabilities for all variables ranged from 43% to 56%. Structural equating modelling revealed that a model with two genetic factors, representing WMS and WMC, which were correlated (− 0.54) fitted the data best, indicating that WMS and WMC are partly mediated by the same set of genes and partly by separate sets of genes. When general IQ was simultaneously analysed with the data the correlation between the genetic factors for WMS and WMC decreased (− 0.25), but was still significant. This means that  50% of the genetic correlation between WMS and WMC is explained by IQ.     

The role of working memory capacity and interference resolution mechanisms in task switching

Theories of task switching have emphasized a number of control mechanisms that may support the ability to flexibly switch between tasks. The present study examined the extent to which individual differences in working memory (WM) capacity and two measures of interference resolution, response–distractor inhibition and resistance to proactive interference (PI), account for variability in task switching, including global costs, local costs, and N-2 repetition costs. A total of 102 young and 60 older adults were tested on a battery of tasks. Composite scores were created for WM capacity, response–distractor inhibition, and resistance to PI; shifting was indexed by rate residual scores, which combine response time and accuracy and account for individual differences in processing speed. Composite scores served as predictors of task switching. WM was significantly related to global switch costs. While resistance to PI and WM explained some variance in local costs, these effects did not reach significance. In contrast, none of the control measures explained variance in N-2 repetition costs. Furthermore, age effects were only evident for N-2 repetition costs, with older adults demonstrating larger costs than young adults. Results are discussed within the context of theoretical models of task switching.     

Relationship between working memory capacity and contingent involuntary orienting

Individual differences in working memory capacity are related to the ability to control attention; where less working memory capacity is associated with less attentional control. A well-known demonstration of attentional control is contingent involuntary orienting (Folk, Remington, & Johnston, 1992), which is the finding that visuospatial attention is captured by a salient peripheral cue, but only if the cue is featurally similar to the target of search and not if the cue is featurally dissimilar. This control of attention and ability to resist shifting attention towards an irrelevant visual cue is believed to be moderated by attentional settings for target-specific features. This study establishes that working memory capacity is related to contingent involuntary orienting of attention. Lower working memory capacity was associated with larger stimulus-driven cueing effects at short cue-to-target onset asynchronies, than at longer asynchronies, suggesting working memory capacity was associated with the ability to control covert orienting of attention at early processing stages.     

Variations in working memory capacity predict individual differences in general learning abilities among genetically diverse mice

Up to 50% of an individuals' performance across a wide variety of distinct cognitive tests can be accounted for by a single factor (i.e., "general intelligence"). Despite its ubiquity, the processes or mechanisms regulating this factor are a matter of considerable debate. Although it has been hypothesized that working memory may impact cognitive performance across various domains, tests have been inconclusive due to the difficulty in isolating working memory from its overlapping operations, such as verbal ability. We address this problem using genetically diverse mice, which exhibit a trait analogous to general intelligence. The general cognitive abilities of CD-1 mice were found to covary with individuals' working memory capacity, but not with variations in long-term retention. These results provide evidence that independent of verbal abilities, variations in working memory are associated with general cognitive abilities, and further, suggest a conservation across species of mechanisms and/or processes that regulate cognitive abilities.     

Effects of emotional content on working memory capacity

Emotional events tend to be remembered better than neutral events, but emotional states and stimuli may also interfere with cognitive processes that underlie memory performance. The current study investigated the effects of emotional content on working memory capacity (WMC), which involves both short term storage and executive attention control. We tested competing hypotheses in a preregistered experiment (N?=?297). The emotional enhancement hypothesis predicts that emotional stimuli attract attention and additional processing resources relative to neutral stimuli, thereby making it easier to encode and store emotional information in WMC. The emotional impairment hypothesis, by contrast, predicts that emotional stimuli interfere with attention control and the active maintenance of information in working memory. Participants completed a common measure of WMC (the operation span task; Turner, M. L., &; Engle, R. W. [1989]. Is working memory capacity task dependent? Journal of Memory and Language, 28, 127–154) that included either emotional or neutral words. Results revealed that WMC was reduced for emotional words relative to neutral words, consistent with the emotional impairment hypothesis.     

Explicit and implicit motor sequence learning in children and adults; the role of age and visual working memory

This study investigated explicit and implicit motor learning, and the influence of visual working memory (VWM) and age. Sixty children and 28 adults learned a nine-button sequence task explicitly and implicitly. Performance in explicit and implicit learning improved with age. Learning curves were similar across ages for implicit learning. In explicit learning, learning curves differed across ages: younger children started slower, but their learning rate was higher compared to older children. Learning curves were similar across VWM scores, but performance in explicit learning was positively influenced by VWM scores. Further research and implications for education and rehabilitation are discussed.     

Different types of working memory binding in epilepsy patients with unilateral anterior temporal lobectomy

The medial temporal lobe is an important structure for long-term memory formation, but its role in working memory is less clear. Recent studies have shown hippocampal involvement during working memory tasks requiring binding of information. It is yet unclear whether this is limited to tasks containing spatial features. The present study contrasted three binding conditions and one single-item condition in patients with unilateral anterior temporal lobectomy.A group of 43 patients with temporal lobectomy (23 left; 20 right) and 20 matched controls were examined with a working memory task assessing spatial relational binding (object–location), non-spatial relational binding (object–object), conjunctive binding (object–colour) and working memory for single items. We varied the delay period (3 or 6 s), as there is evidence showing that delay length may modulate working memory performance.The results indicate that performance was worse for patients than for controls in both relational binding conditions, whereas patients were unimpaired in conjunctive binding. Single-item memory was found to be marginally impaired, due to a deficit on long-delay trials only.In conclusion, working memory binding deficits are found in patients with unilateral anterior temporal lobectomy. The role of the medial temporal lobe in working memory is not limited to tasks containing spatial features. Rather, it seems to be involved in relational binding, but not in conjunctive binding. The medial temporal lobe gets involved when working memory capacity does not suffice, for example when relations have to be maintained or when the delay period is long.     

Category-based grouping in working memory and multiple object tracking

Two prominent cognitive capacity limitations are the maximal number of objects we can place in working memory (WM) and the maximal number of objects we can track in a display. Both are believed to have a numeric value of 3 or 4, which has led to the proposal that we have a general cognitive capacity, and that this capacity is most likely linked to limitations of how many objects we can attend simultaneously. Based on previous results showing that we can memorize more objects if they come from different categories than if they come from the same category (e.g., Feigenson & Halberda, 2008; Wong, Peterson, & Thompson, 2008; Wood, 2008), we compare how category-based grouping affects performance for WM and multiple object tracking (MOT). We present participants with either “pure” displays of either cars or faces, or with “mixed” displays of cars and faces. Overall, the effects of category are weak. In some analyses but not others, we replicate the mixed advantage for WM, albeit with a small effect size. In contrast, we observe a weak pure advantage for MOT tasks, at least in a meta-analysis of five experiments, but not in all experiments. Accordingly, WM and MOT tasks differed significantly in their sensitivity to category membership. We also find that WM is slightly better for faces than for cars, but that no such difference exists for MOT. We tentatively suggest that cognitive capacity limitations in different domains are at least partially due to the limitations of distinct mechanisms.     

Low working memory capacity impedes both efficiency and learning of number transcoding in children

This study aimed to evaluate the impact of individual differences in working memory capacity on number transcoding. A recently proposed model, ADAPT (a developmental asemantic procedural transcoding model), accounts for the development of number transcoding from verbal form to Arabic form by two mechanisms: the learning of new production rules that enlarge the range of numbers a child can transcode and the increase of the mental lexicon. The working memory capacity of 7-year-olds was evaluated along with their ability to transcode one- to four-digit numbers. As ADAPT predicts, the rate of transcoding errors increased when more production rules were required and when children had low working memory capacity, with these two factors interacting. Moreover, qualitative analysis of the errors produced by high- and low-span children showed that the latter have a developmental delay in the acquisition of the production rules.