A sub-process view of working memory capacity: Evidence from effects of speech on prose memory

In this article we outline a “sub-process view” of working memory capacity (WMC). This view suggests that any relationship between WMC and another construct (e.g., reading comprehension) is actually a relationship with a specific part of the WMC construct. The parts, called sub-processes, are functionally distinct and can be measured by intrusion errors in WMC tasks. Since the sub-processes are functionally distinct, some sub-process may be related to a certain phenomenon, whereas another sub-process is related to other phenomena. In two experiments we show that a sub-process (measured by immediate/current-list intrusions) is related to the effects of speech on prose memory (semantic auditory distraction), whereas another sub-process (measured by delayed/prior-list intrusions), known for its contribution to reading comprehension, is not. In Experiment 2 we developed a new WMC task called “size-comparison span” and found that the relationship between WMC and semantic auditory distraction is actually a relationship with a sub-process measured by current-list intrusions in our new task.     

Similar patterns of age-related differences in emotion recognition from speech and music

Young and old adults’ ability to recognize emotions from vocal expressions and music performances was compared. The stimuli consisted of (a) acted speech (anger, disgust, fear, happiness, and sadness; each posed with both weak and strong emotion intensity), (b) synthesized speech (anger, fear, happiness, and sadness), and (c) short melodies played on the electric guitar (anger, fear, happiness, and sadness; each played with both weak and strong emotion intensity). The listeners’ recognition of discrete emotions and emotion intensity was assessed and the recognition rates were controlled for various response biases. Results showed emotion-specific age-related differences in recognition accuracy. Old adults consistently received significantly lower recognition rates for negative, but not for positive, emotions for both speech and music stimuli. Some age-related differences were also evident in the listeners’ ratings of emotion intensity. The results show the importance of considering individual emotions in studies on age-related differences in emotion recognition.     

Effects of training on age estimation

This study examined the possibility to improve accuracy of age estimates through training. Thirty‐four participants were divided into an experimental and a control group. The sessions included a pre‐test before training, six feedback or no‐feedback training tests and a post‐test after training. The experimental group performed the feedback tests and the control group the no‐feedback tests. Training was found to improve age estimation accuracy, particularly estimations of old stimuli, and training with feedback seemed to be superior to training without feedback. No difference was found between the groups at pre‐test, but at post‐test the experimental group exhibited greater accuracy in age estimation. Moreover, the experimental group increased its accuracy between the pre‐ and post‐tests. Copyright © 2006 John Wiley & Sons, Ltd.     

Updating working memory in aircraft noise and speech noise causes different fMRI activations

The present study used fMRI/BOLD neuroimaging to investigate how visual‐verbal working memory is updated when exposed to three different background‐noise conditions: speech noise, aircraft noise and silence. The number‐updating task that was used can distinguish between “substitution processes,” which involve adding new items to the working memory representation and suppressing old items, and “exclusion processes,” which involve rejecting new items and maintaining an intact memory set. The current findings supported the findings of a previous study by showing that substitution activated the dorsolateral prefrontal cortex, the posterior medial frontal cortex and the parietal lobes, whereas exclusion activated the anterior medial frontal cortex. Moreover, the prefrontal cortex was activated more by substitution processes when exposed to background speech than when exposed to aircraft noise. These results indicate that (a) the prefrontal cortex plays a special role when task‐irrelevant materials should be denied access to working memory and (b) that, when compensating for different types of noise, either different cognitive mechanisms are involved or those cognitive mechanisms that are involved are involved to different degrees.     

High working memory capacity does not always attenuate distraction: Bayesian evidence in support of the null hypothesis

Individual differences in working memory capacity (WMC) predict individual differences in basically all tasks that demand some form of cognitive labor, especially if the persons conducting the task are exposed to distraction. As such, tasks that measure WMC are very useful tools in individual-differences research. However, the predictive power of those tasks, combined with conventional statistical tools that cannot support the null hypothesis, also makes it difficult to study the limits of that power. In this article, we review studies that have failed to find a relationship between WMC and effects of auditory distraction on visual–verbal cognitive performance, and use meta-analytic Bayesian statistics to test the null hypothesis. The results favor the assumption that individual differences in WMC are, in fact, not (always) related to the magnitude of distraction. Implications for the nature of WMC are discussed.     

Trouble articulating the right words: Evidence for a response‐exclusion account of distraction during semantic fluency

It is widely held that single‐word lexical access is a competitive process, a view based largely on the observation that naming a picture is slowed in the presence of a distractor‐word. However, problematic for this view is that a low‐frequency distractor‐word slows the naming of a picture more than does a high‐frequency word. This supports an alternative, response‐exclusion, account in which a distractor‐word interferes because it must be excluded from an articulatory output buffer before the right word can be articulated (the picture name): A high, compared to low, frequency word accesses the buffer more quickly and, as such, can also be excluded more quickly. Here we studied the respective roles of competition and response‐exclusion for the first time in the context of semantic verbal fluency, a setting requiring the accessing of, and production of, multiple words from long‐term memory in response to a single semantic cue. We show that disruption to semantic fluency by a sequence of to‐be‐ignored spoken distractors is also greater when those distractors are low in frequency, thereby extending the explanatory compass of the response‐exclusion account to a multiple‐word production setting and casting further doubt on the lexical‐selection‐by‐competition view. The results can be understood as reflecting the contribution of speech output processes to semantic fluency.     

Hemispheric asymmetries in auditory distraction

Serial-verbal short-term memory is impaired by irrelevant sound, particularly when the sound changes acoustically (the changing-state effect). In contrast, short-term recall of semantic information is impaired only by the semanticity of irrelevant speech, particularly when it is semantically related to the target memory items (the between-sequence semantic similarity effect). Previous research indicates that the changing-state effect is larger when the sound is presented to the left ear in comparison to the right ear, the left ear disadvantage. In this paper, we report a novel finding whereby the between-sequence semantic similarity effect is larger when the irrelevant speech is presented to the right ear in comparison to the left ear, but this right ear disadvantage is found only when meaning is the basis of recall (Experiments 1 and 3), not when order is the basis of recall (Experiment 2). Our results complement previous research on hemispheric asymmetry effects in cross-modal auditory distraction by demonstrating a role for the left hemisphere in semantic auditory distraction.     

The role of short-term memory capacity and task experience for overconfidence in judgment under uncertainty

Research with general knowledge items demonstrates extreme overconfidence when people estimate confidence intervals for unknown quantities, but close to zero overconfidence when the same intervals are assessed by probability judgment. In 3 experiments, the authors investigated if the overconfidence specific to confidence intervals derives from limited task experience or from short-term memory limitations. As predicted by the naive sampling model (P. Juslin, A. Winman, & P. Hansson, 2007), overconfidence with probability judgment is rapidly reduced by additional task experience, whereas overconfidence with intuitive confidence intervals is minimally affected even by extensive task experience. In contrast to the minor bias with probability judgment, the extreme overconfidence bias with intuitive confidence intervals is correlated with short-term memory capacity. The proposed interpretation is that increased task experience is not sufficient to cure the overconfidence with confidence intervals because it stems from short-term memory limitations.     

Emotional responses to music: the need to consider underlying mechanisms

Research indicates that people value music primarily because of the emotions it evokes. Yet, the notion of musical emotions remains controversial, and researchers have so far been unable to offer a satisfactory account of such emotions. We argue that the study of musical emotions has suffered from a neglect of underlying mechanisms. Specifically, researchers have studied musical emotions without regard to how they were evoked, or have assumed that the emotions must be based on the "default" mechanism for emotion induction, a cognitive appraisal. Here, we present a novel theoretical framework featuring six additional mechanisms through which music listening may induce emotions: (1) brain stem reflexes, (2) evaluative conditioning, (3) emotional contagion, (4) visual imagery, (5) episodic memory, and (6) musical expectancy. We propose that these mechanisms differ regarding such characteristics as their information focus, ontogenetic development, key brain regions, cultural impact, induction speed, degree of volitional influence, modularity, and dependence on musical structure. By synthesizing theory and findings from different domains, we are able to provide the first set of hypotheses that can help researchers to distinguish among the mechanisms. We show that failure to control for the underlying mechanism may lead to inconsistent or non-interpretable findings. Thus, we argue that the new framework may guide future research and help to resolve previous disagreements in the field. We conclude that music evokes emotions through mechanisms that are not unique to music, and that the study of musical emotions could benefit the emotion field as a whole by providing novel paradigms for emotion induction.     

Physical Activity and Physical Self-Concept among Sedentary Adolescent Females; An Intervention Study

PROBLEM: Physical activity has been promoted as a means of enhancing self-concept, yet the evidence for this connection is far from compelling. In particular, experimental research investigating this association during adolescence, a period during which many youth struggle to maintain a positive self-image, is noticeably lacking. This study investigates the impact on self-concept of a 9-month physical activity intervention among sedentary adolescent females. METHOD: Female adolescents who were sedentary at baseline were assigned either to an exercise intervention or a comparison group as part of the controlled trial. The intervention was school-based, and assignment to groups was based on school attended. Intervention participants engaged in supervised activity 4 times per week and received didactic instruction promoting activity outside of school 1 day per week. Self-concept, physical activity participation, and cardiovascular fitness were assessed before, mid-way through, and after the 9-month intervention. RESULTS: The intervention had a significant positive impact on participation in vigorous activity and cardiovascular fitness. The intervention did not significantly influence any of the self-concept dimensions overall. There was, however, a three-way interaction such that there was an increase in global physical self-concept among those intervention participants who increased cardiovascular fitness. CONCLUSIONS: These findings indicate that a physical activity intervention among sedentary adolescent females enhanced global physical self-concept for a subset of intervention participants who manifested positive changes in fitness.