How Concentration Shields Against Distraction

Task-irrelevant decorative pictures increase cognitive load during text processing but have no effects on learning or working memory performance: an EEG and eye-tracking study

Decorative pictures (DP) are often used in multimedia task materials and are commonly considered so-called seductive details as they are commonly not task-relevant. Typically, DP result in mixed effects on behavioral performance measures. The current study focused on the effects of DP on the cognitive load during text reading and working memory task performance. The theta and alpha frequency band power of the electroencephalogram (EEG) and pupil dilation served as proxies of cognitive load. The number of fixations, mean fixation durations, and the number of transitions served as proxies of the attentional focus. For both, text reading and n-back working memory tasks, the presence and congruency of DP were manipulated in four task conditions. DP did neither affect behavioral performance nor subjective ratings of emotional-motivational factors. However, in both tasks, DP increased the cognitive load as revealed by the EEG alpha frequency band power and (at least to some extent) by subjective effort ratings. Notably, the EEG alpha frequency band power was a quite reliable and sensitive proxy of cognitive load. Analyzing the EEG data stimulus-locked and fixation-related, the EEG alpha frequency band power revealed a difference in global and local cognitive load. In sum, the current study underlines the feasibility and use of EEG for multimedia research, especially when combined with eye-tracking.

Improving Adherence to Physical Therapy in the Development of Serious Games: Conceptual Framework Design Study

BACKGROUND

Insufficient levels of treatment adherence can have adverse effects on the outcomes of physical rehabilitation. To address this issue, alternative approaches to traditional therapies, such as serious games, have been designed to enhance adherence. Nevertheless, there remain gaps in the development of serious games concerning the effective implementation of motivation, engagement, and the enhancement of treatment adherence.

OBJECTIVE

This study aims to design a conceptual framework for the development of serious games that incorporate essential adherence factors to enhance patient compliance with physical rehabilitation programs.

METHODS

We formulated a conceptual framework using iterative techniques inspired by a conceptual framework analysis. Initially, we conducted a comprehensive literature review, concentrating on the critical adherence factors in physical rehabilitation. Subsequently, we identified, categorized, integrated, and synthesized the concepts derived from the literature review to construct the conceptual framework.

RESULTS

The framework resembles a road map, comprising 3 distinct phases. In the initial phase, the patient's characteristics are identified through an initial exploration. The second phase involves the development of a serious game, with a focus on enhancing treatment adherence by integrating the key adherence factors identified. The third phase revolves around the evaluation of the serious game. These phases are underpinned by 2 overarching themes, namely, a user-centered design and the GameFlow model.

CONCLUSIONS

The conceptual framework offers a detailed, step-by-step guide for creating serious games that incorporate essential adherence factors, thereby contributing to improved adherence in the physical rehabilitation process. To establish its validity, further evaluations of this framework across various physical rehabilitation programs and user groups are necessary.

Is the deficit in attention-deficit/hyperactivity disorder a concentration deficit?

Attention-deficit/hyperactivity disorder (ADHD) is comprised of two behavioral clusters of symptoms, inattention and hyperactivity/impulsivity. Numerous studies have attempted to address the underlying neuropsychological mechanism of ADHD. However, there is still no uniform mechanism that can fully explain both inattention and hyperactivity/impulsivity symptoms. This review describes the research findings that have shifted the focus from cognitive selective attention to executive function deficits and notes that the prominence of the attention deficit remains unclear. As ADHD is not consistently explained by cognitive selective attention but rather with cognitive sustained attention/vigilance and executive function deficits, this review suggests that concentration deficit is likely the cause of inattention symptoms. Indeed, considering concentration deficit as the cause of inattention symptoms may better describe the underlying difficulties of maintaining and controlling attention in ADHD. In addition, as concentration, impulsivity, and hyperactivity may share a common cognitive deficit, this shift in focus may help in identifying a single mechanism for all ADHD symptoms.

Distraction from pain depends on task demands and motivation

Supplemental Digital Content is Available in the Text.

Distraction is effective at reducing pain when the task is both cognitively demanding and there is sufficient motivation to invest effort into the task.

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Effects of inhibitory control capacity and cognitive load on involuntary past and future thoughts: A laboratory study

The present study focused on involuntary thoughts about personal past events (i.e., involuntary autobiographical memories; IAMs), and involuntary thoughts about future events and plans (i.e., involuntary future thoughts; IFTs). The frequency of these involuntary thoughts is influenced by cognitive demands of ongoing activities, but the exact underlying mechanism(s) has yet to be revealed. The present study tested two possible explanations: (1) the special inhibitory mechanism switches on when one is engaged in attentionally demanding activities; (2) different levels of cognitive load interfere with cue-noticing that act as triggers for IAMs and IFTs. We report a study with pre-selected groups of participants that differed in terms of their individual level of inhibitory control capacity (high vs. low), and completed both standard and attentionally demanding versions of a laboratory vigilance task with irrelevant cue-words to trigger IAMs and IFTs, and random thought-probes to measure their frequency. To examine the level of incidental cue-noticing, participants also completed an unexpected cue-recognition task. Despite large differences between groups in inhibitory control capacity, the number of IFTs and IAMs, reported in the attentionally demanding condition, was comparable. In addition, high cognitive load reduced the number of IAMs, but not IFTs. Finally, the recognition of incidental cues encountered in the vigilance task was reduced under high cognitive load condition, indicating that poor cue-noticing may be the main underlying mechanism of cognitive load effect rather than the lack of inhibitory resources needed to suppress involuntary retrieval. This and other possible mechanisms and avenues for future research are discussed.

Optimization of the Cognitive Processes in a Virtual Classroom: A Multi-objective Integer Linear Programming Approach

A fundamental problem in the design of a classroom is to identify what characteristics it should have in order to optimize learning. This is a complex problem because learning is a construct related to several cognitive processes. The aim of this study is to maximize learning, represented by the processes of attention, memory, and preference, depending on six classroom parameters: height, width, color hue, color saturation, color temperature, and illuminance. Multi-objective integer linear programming with three objective functions and 56 binary variables was used to solve this optimization problem. Virtual reality tools were used to gather the data; novel software was used to create variations of virtual classrooms for a sample of 112 students. Using an interactive method, more than 4700 integer linear programming problems were optimally solved to obtain 13 efficient solutions to the multi-objective problem, which allowed the decision maker to analyze all the information and make a final choice. The results showed that achieving the best cognitive processing performance involves using different classroom configurations. The use of a multi-objective interactive approach is interesting because in human behavioral studies, it is important to consider the judgement of an expert in order to make decisions.

The Effects of Working Memory Load on Auditory Distraction in Adults With Attention Deficit Hyperactivity Disorder

Cognitive control provides us with the ability to inter alia, regulate the locus of attention and ignore environmental distractions in accordance with our goals. Auditory distraction is a frequently cited symptom in adults with attention deficit hyperactivity disorder (aADHD)-yet few task-based fMRI studies have explored whether deficits in cognitive control (associated with the disorder) impedes on the ability to suppress/compensate for exogenously evoked cortical responses to noise in this population. In the current study, we explored the effects of auditory distraction as function of working memory (WM) load. Participants completed two tasks: an auditory target detection (ATD) task in which the goal was to actively detect salient oddball tones amidst a stream of standard tones in noise, and a visual n-back task consisting of 0-, 1-, and 2-back WM conditions whilst concurrently ignoring the same tonal signal from the ATD task. Results indicated that our sample of young aADHD (n = 17), compared to typically developed controls (n = 17), had difficulty attenuating auditory cortical responses to the task-irrelevant sound when WM demands were high (2-back). Heightened auditory activity to task-irrelevant sound was associated with both poorer WM performance and symptomatic inattentiveness. In the ATD task, we observed a significant increase in functional communications between auditory and salience networks in aADHD. Because performance outcomes were on par with controls for this task, we suggest that this increased functional connectivity in aADHD was likely an adaptive mechanism for suboptimal listening conditions. Taken together, our results indicate that aADHD are more susceptible to noise interference when they are engaged in a primary task. The ability to cope with auditory distraction appears to be related to the WM demands of the task and thus the capacity to deploy cognitive control.

The impact of auditory distraction on reading comprehension: An individual differences investigation

Background noise disrupts auditory selective attention and impairs performance on cognitive tasks, but the degree to which it is disruptive depends on the task and the individual. According to the load theory of attention and cognitive control, selective attention is influenced by both the perceptual load and the cognitive load of the primary task. Recent studies suggest that hard-to-read font in a reading task may shield attention against background noise and auditory distraction. The current study examined the disruptive effect of background noise on reading comprehension as a function of perceptual load and cognitive load. Perceptual load was manipulated by introducing task disfluency (hard-to-read or easy-to-read font), and cognitive load was manipulated by varying the type of background noise and investigating individual differences in working memory capacity. The results suggest that high perceptual load and high working memory capacity both facilitate reading comprehension. However, contrary to previous research, neither perceptual load nor capacity moderates the disruptive effect of background noise. These results failed to support the generalizability and applicability of the shield effect of perceptual disfluency against auditory distraction during reading but supported the beneficial effect of perceptual disfluency on reading comprehension.

The role of inhibitory control and ADHD symptoms in the occurrence of involuntary thoughts about the past and future: An individual differences study

In everyday life, people often experience involuntary thoughts about their personal past and future events in response to incidental cues in the environment. Yet, despite the abundance of such cues, our consciousness is not constantly flooded by these involuntary autobiographical memories (IAMs) and involuntary future thoughts (IFTs). The main goal of the present study was to further investigate the possibility that cognitive inhibitory control keeps these involuntary cognitions at bay. To test this inhibition hypothesis, we conducted a large-scale study (n = 157) in which groups of participants with different levels of inhibitory control (low, medium, high) and individuals with ADHD spectrum symptoms were engaged in a laboratory vigilance task in which the frequency of IFTs and IAMs was assessed. Contrary to predictions, although participants across groups differed significantly in terms of their individual inhibitory control capacity, the number of IFTs and IAMs reported during the vigilance task was comparable. In addition, individuals with the ADHD spectrum symptoms did not report more spontaneous thoughts compared to other groups. Together, these findings lend little support for the idea that inhibition is a key mechanism that regulates the occurrence of IAMs and IFTs in everyday life. Other possible mechanisms and avenues for future research are discussed.

Word Identification With Temporally Interleaved Competing Sounds by Younger and Older Adult Listeners

OBJECTIVES

The purpose of this experiment was to contribute to our understanding of the nature of age-related changes in competing speech perception using a temporally interleaved task.

DESIGN

Younger and older adults (n = 16/group) participated in this study. The target was a five-word sentence. The masker was one of the following: another five-word sentence; five brief samples of modulated noise; or five brief samples of environmental sounds. The stimuli were presented in a temporally interleaved manner, where the target and masker alternated in time, always beginning with the target. Word order was manipulated in the target (and in the masker during trials with interleaved words) to compare performance when the five words in each stream did versus did not create a syntactically correct sentence. Talker voice consistency also was examined by contrasting performance when each word in the target was spoken by the same talker or by different talkers; a similar manipulation was used for the masker when it consisted of words. Participants were instructed to repeat back the target words and ignore the intervening words or sounds. Participants also completed a subset of tests from the NIH Cognitive Toolbox.

RESULTS

Performance on this interleaved task was significantly associated with listener age and with a metric of cognitive flexibility, but it was not related to the degree of high-frequency hearing loss. Younger adults' performance on this task was better than that of older adults, especially for words located toward the end of the sentence. Both groups of participants were able to take advantage of correct word order in the target, and both were negatively affected, to a modest extent, when the masker words were in correct syntactic order. The two groups did not differ in how phonetic similarity between target and masker words influenced performance, and interleaved environmental sounds or noise had only a minimal effect for all listeners. The most robust difference between listener groups was found for the use of voice consistency: older adults, as compared with younger adults, were less able to take advantage of a consistent target talker within a trial.

CONCLUSIONS

Younger adults outperformed older adults when masker words were interleaved with target words. Results suggest that this difference was unlikely to be related to energetic masking and/or peripheral hearing loss. Rather, age-related changes in cognitive flexibility and problems encoding voice information appeared to underlie group differences. These results support the contention that, in real-life competing speech situations that produce both energetic and informational masking, older adults' problems are due to both peripheral and nonperipheral changes.

A review of decreased sound tolerance in autism: Definitions, phenomenology, and potential mechanisms

Atypical behavioral responses to environmental sounds are common in autistic children and adults, with 50-70 % of this population exhibiting decreased sound tolerance (DST) at some point in their lives. This symptom is a source of significant distress and impairment across the lifespan, contributing to anxiety, challenging behaviors, reduced community participation, and school/workplace difficulties. However, relatively little is known about its phenomenology or neurocognitive underpinnings. The present article synthesizes a large body of literature on the phenomenology and pathophysiology of DST-related conditions to generate a comprehensive theoretical account of DST in autism. Notably, we argue against conceptualizing DST as a unified construct, suggesting that it be separated into three phenomenologically distinct conditions: hyperacusis (the perception of everyday sounds as excessively loud or painful), misophonia (an acquired aversive reaction to specific sounds), and phonophobia (a specific phobia of sound), each responsible for a portion of observed DST behaviors. We further elaborate our framework by proposing preliminary neurocognitive models of hyperacusis, misophonia, and phonophobia that incorporate neurophysiologic findings from studies of autism.

Neural correlates of working memory's suppression of aversive olfactory distraction effects

Human cognitive performance is often disrupted by distractions related to aversive stimuli and affective states, but, paradoxically, there is also evidence to suggest that high working memory demands reduce the impact of aversive distraction. Previous empirical work suggests this latter effect occurs because working memory demands reduce attention to off-task processes, but the brain regions that mediate this effect remain uncertain. The current study utilizes a novel distraction manipulation involving unpleasant odorants to identify neural structures that buffer performance from aversive distraction under high working memory demands, and to clarify their connectivity in this context. Twenty-one healthy young adults (12 women) completed a verbal n-back task under two levels of load and were concurrently exposed to either room air or aversive odorants. Three brain regions displayed increases in neural responses to olfactory distractors under high load only; the left dorsolateral prefrontal cortex, the left ventrolateral prefrontal cortex and right cerebellar Crus I. Of these regions, only the ventrolateral prefrontal cortex also displayed context-specific connectivity with a region thought to be involved in off-task processes: the dorsomedial prefrontal cortex. Overall, results suggest that, under high working memory demands, areas of the prefrontal cortex and cerebellum shield cognition from aversive distraction, potentially through interactions with brain structures involved in off-task processes.

Does working memory protect against auditory distraction in older adults?

BACKGROUND

Past research indicates that when younger adults are engaged in a visual working memory task, they are less distracted by novel auditory stimuli than when engaged in a visual task that does not require working memory. The current study aimed to determine whether working memory affords the same protection to older adults.

METHOD

We examined behavioral and EEG responses in 16 younger and 16 older adults to distractor sounds when the listeners performed two visual tasks; one that required working memory (W1) and the other that did not (W0). Auditory distractors were presented in an oddball paradigm, participants were exposed to either standard tones (600 Hz: 80%) or various novel environmental sounds (20%).

RESULTS

It was found that: 1) when presented with novel vs standard sounds, older adults had faster correct response times in the W1 visual task than in the W0 task, indicating that they were less distracted by the novel sound; there was no difference in error rates. Younger adults did not show a task effect for correct response times but made slightly more errors when a novel sound was presented in the W1 task compared to the W0 task. 2) In older adults (but not the younger adults), the amplitude of N1 was smaller in the W1 condition compared to the W0 condition. 3) The working memory manipulation had no effect on MMN amplitude in older adults. 4) For the W1 compared to W0 task, the amplitude of P3a was attenuated for the older adults but not for the younger adults.

CONCLUSIONS

These results suggest that during the working memory manipulation older adults were able to engage working memory to reduce the processing of task-irrelevant sounds.

Auditory selective attention under working memory load

Can cognitive load enhance concentration on task-relevant information and help filter out distractors? Most of the prior research in the area of selective attention has focused on visual attention or cross-modal distraction and has yielded controversial results. Here, we studied whether working memory load can facilitate selective attention when both target and distractor stimuli are auditory. We used a letter n-back task with four levels of working memory load and two levels of distraction: congruent and incongruent distractors. This combination of updating and inhibition tasks allowed us to manipulate working memory load within the selective attention task. Participants sat in front of three loudspeakers and were asked to attend to the letter presented from the central loudspeaker while ignoring that presented from the flanking ones (spoken by a different person), which could be the same letter as the central one (congruent) or a different (incongruent) letter. Their task was to respond whether or not the central letter matched the letter presented n (0, 1, 2, or 3) trials back. Distraction was measured in terms of the difference in reaction time and accuracy on trials with incongruent versus congruent flankers. We found reduced interference from incongruent flankers in 2- and 3-back conditions compared to 0- and 1-back conditions, whereby higher working memory load almost negated the effect of incongruent flankers. These results suggest that high load on verbal working memory can facilitate inhibition of distractors in the auditory domain rather than make it more difficult as sometimes claimed.

How the deployment of visual attention modulates auditory distraction

Classically, attentional selectivity has been conceptualized as a passive by-product of capacity limits on stimulus processing. Here, we examine the role of more active cognitive control processes in attentional selectivity, focusing on how distraction from task-irrelevant sound is modulated by levels of task engagement in a visually presented short-term memory task. Task engagement was varied by manipulating the load involved in the encoding of the (visually presented) to-be-remembered items. Using a list of Navon letters (where a large letter is composed of smaller, different-identity letters), participants were oriented to attend and serially recall the list of large letters (low encoding load) or to attend and serially recall the list of small letters (high encoding load). Attentional capture by a single deviant noise burst within a task-irrelevant tone sequence (the deviation effect) was eliminated under high encoding load (Experiment 1). However, distraction from a continuously changing sequence of tones (the changing-state effect) was immune to the influence of load (Experiment 2). This dissociation in the amenability of the deviation effect and the changing-state effect to cognitive control supports a duplex-mechanism over a unitary-mechanism account of auditory distraction in which the deviation effect is due to attentional capture whereas the changing-state effect reflects direct interference between the processing of the sound and processes involved in the focal task. That the changing-state effect survives high encoding load also goes against an alternative explanation of the attenuation of the deviation effect under high load in terms of the depletion of a limited perceptual resource that would result in diminished auditory processing.

Visual attentional load affects the frequency of involuntary autobiographical memories and their level of meta-awareness

Involuntary autobiographical memories (IAMs) are memories of past events that come to mind without deliberate retrieval attempts. Common in everyday life, IAMs have recently become a topic of experimental investigations with laboratory procedures. In the present study, we build on the recent methodological advancements in the study of IAMs, and we investigate the effects of manipulating the attentional load on the incidence of IAMs, as well as on the level of meta-awareness of these memories. In two experiments, attentional load was manipulated by varying the demands of the focal vigilance task, and reports of IAMs were collected. In Experiment 1, participants were instructed to stop the vigilance task whenever mental contents unrelated to the task came to their minds (self-caught method). In Experiment 2, participants were intermittently interrupted and probed regarding the contents of their experience (probe-caught method) and the level of meta-awareness for these contents. In both experiments, we found a reduction in the frequency of reported IAMs under increased attentional load. Moreover, in Experiment 2, IAMs were characterized by varied levels of meta-awareness, which was reduced by increased attentional load. These results indicate that allocation of attentional resources toward a focal task reduces reporting of IAMs experienced while performing this task because attentional resources play a role in both retrieval of IAMs and the realization that one is experiencing a memory.

The Impact of Cognitive Load on the Cardiac Orienting Response to Auditory Structural Features during Natural Radio Listening Situations

Previous research has shown that structural features such as voice changes, jingle onsets, and production effects in a radio broadcast elicit cardiac orienting responses. In fact, the voice change has been shown to reliably elicit orienting without habituation after several repetitions. However, repeated onsets of two other auditory structural features-jingles and production effects-did result in habituation when the participant was exposed to them embedded in an audio production absent a central cognitive task. This article presents two experiments testing the possibility that adding a central task prevents the development of a robust neural model of the auditory structural features necessary for habituation. In both studies, results show that adding a primary cognitive task eliminated habituation to jingles and production effects. However, varying the cognitive load of the primary task across two levels of difficulty had no significant effect on habituation.

Auditory Distraction During Reading: A Bayesian Meta-Analysis of a Continuing Controversy

Everyday reading occurs in different settings, such as on the train to work, in a busy cafeteria, or at home while listening to music. In these situations, readers are exposed to external auditory stimulation from nearby noise, speech, or music that may distract them from their task and reduce their comprehension. Although many studies have investigated auditory-distraction effects during reading, the results have proved to be inconsistent and sometimes even contradictory. In addition, the broader theoretical implications of the findings have not always been explicitly considered. We report a Bayesian meta-analysis of 65 studies on auditory-distraction effects during reading and use metaregression models to test predictions derived from existing theories. The results showed that background noise, speech, and music all have a small but reliably detrimental effect on reading performance. The degree of disruption in reading comprehension did not generally differ between adults and children. Intelligible speech and lyrical music resulted in the biggest distraction. Although this last result is consistent with theories of semantic distraction, there was also reliable distraction by noise. It is argued that new theoretical models are needed that can account for distraction by both background speech and noise.

Can Intrinsic and Extrinsic Metacognitive Cues Shield Against Distraction in Problem Solving?

We investigated the capacity for two different forms of metacognitive cue to shield against auditory distraction in problem solving with Compound Remote Associates Tasks (CRATs). Experiment 1 demonstrated that an intrinsic metacognitive cue in the form of processing disfluency (manipulated using an easy-to-read vs. difficult-to-read font) could increase focal task engagement so as to mitigate the detrimental impact of distraction on solution rates for CRATs. Experiment 2 showed that an extrinsic metacognitive cue that took the form of an incentive for good task performance (i.e. 80% or better CRAT solutions) could likewise eliminate the negative impact of distraction on CRAT solution rates. Overall, these findings support the view that both intrinsic and extrinsic metacognitive cues have remarkably similar effects. This suggests that metacognitive cues operate via a common underlying mechanism whereby a participant applies increased focal attention to the primary task so as to ensure more steadfast task engagement that is not so easily diverted by task-irrelevant stimuli.

Task-Irrelevant Novel Sounds have Antithetical Effects on Visual Target Processing in Young and Old Adults

In young adults, primary visual task processing can be either enhanced or disrupted by novel auditory stimuli preceding target events, depending on task demands. Little is known about this phenomenon in older individuals, who, in general, are more susceptible to distraction. In the current study, age-related differences in the electrophysiological effects of task-irrelevant auditory stimuli on visual target processing were examined. Under both low and high primary task loads, the categorization/updating process in response to visual targets preceded by auditory novels, as indexed by the target P3 component, was enhanced in young, but diminished in old adults. In both age groups, the alerting/orienting response to novel auditory stimuli, as measured by the P3a, was smaller under high task load, whereas redirecting attention to the visual task after a novel auditory event, as indexed by the reorienting negativity (RON), tended to be augmented under high task load. Old subjects generated a smaller P3a and RON. We conclude that task irrelevant novel auditory stimuli have the opposite effect on the processing of visual targets in young and old adults. This finding may help explain age-related increases in the disruption of primary task activity by irrelevant, but salient auditory events.

Increased Early Processing of Task-Irrelevant Auditory Stimuli in Older Adults

The inhibitory deficit hypothesis of cognitive aging posits that older adults' inability to adequately suppress processing of irrelevant information is a major source of cognitive decline. Prior research has demonstrated that in response to task-irrelevant auditory stimuli there is an age-associated increase in the amplitude of the N1 wave, an ERP marker of early perceptual processing. Here, we tested predictions derived from the inhibitory deficit hypothesis that the age-related increase in N1 would be 1) observed under an auditory-ignore, but not auditory-attend condition, 2) attenuated in individuals with high executive capacity (EC), and 3) augmented by increasing cognitive load of the primary visual task. ERPs were measured in 114 well-matched young, middle-aged, young-old, and old-old adults, designated as having high or average EC based on neuropsychological testing. Under the auditory-ignore (visual-attend) task, participants ignored auditory stimuli and responded to rare target letters under low and high load. Under the auditory-attend task, participants ignored visual stimuli and responded to rare target tones. Results confirmed an age-associated increase in N1 amplitude to auditory stimuli under the auditory-ignore but not auditory-attend task. Contrary to predictions, EC did not modulate the N1 response. The load effect was the opposite of expectation: the N1 to task-irrelevant auditory events was smaller under high load. Finally, older adults did not simply fail to suppress the N1 to auditory stimuli in the task-irrelevant modality; they generated a larger response than to identical stimuli in the task-relevant modality. In summary, several of the study's findings do not fit the inhibitory-deficit hypothesis of cognitive aging, which may need to be refined or supplemented by alternative accounts.

Distracted While Reading? Changing to a Hard-to-Read Font Shields against the Effects of Environmental Noise and Speech on Text Memory

The purpose of this study was to investigate the distractive effects of background speech, aircraft noise and road traffic noise on text memory and particularly to examine if displaying the texts in a hard-to-read font can shield against the detrimental effects of these types of background sounds. This issue was addressed in an experiment where 56 students read shorter texts about different classes of fictitious creatures (i.e., animals, fishes, birds, and dinosaurs) against a background of the aforementioned background sounds respectively and silence. For half of the participants the texts were displayed in an easy-to-read font (i.e., Times New Roman) and for the other half in a hard-to-read font (i.e., Haettenschweiler). The dependent measure was the proportion correct answers on the multiple-choice tests that followed each sound condition. Participants’ performance in the easy-to-read font condition was significantly impaired by all three background sound conditions compared to silence. In contrast, there were no effects of the three background sound conditions compared to silence in the hard-to-read font condition. These results suggest that an increase in task demand—by displaying the text in a hard-to-read font—shields against various types of distracting background sounds by promoting a more steadfast locus-of-attention and by reducing the processing of background sound.

Increasing Working Memory Load Reduces Processing of Cross-Modal Task-Irrelevant Stimuli Even after Controlling for Task Difficulty and Executive Capacity

The classic account of the load theory (LT) of attention suggests that increasing cognitive load leads to greater processing of task-irrelevant stimuli due to competition for limited executive resource that reduces the ability to actively maintain current processing priorities. Studies testing this hypothesis have yielded widely divergent outcomes. The inconsistent results may, in part, be related to variability in executive capacity (EC) and task difficulty across subjects in different studies. Here, we used a cross-modal paradigm to investigate whether augmented working memory (WM) load leads to increased early distracter processing, and controlled for the potential confounders of EC and task difficulty. Twenty-three young subjects were engaged in a primary visual WM task, under high and low load conditions, while instructed to ignore irrelevant auditory stimuli. Demands of the high load condition were individually titrated to make task difficulty comparable across subjects with differing EC. Event-related potentials (ERPs) were used to measure neural activity in response to stimuli presented in both the task relevant modality (visual) and task-irrelevant modality (auditory). Behavioral results indicate that the load manipulation and titration procedure of the primary visual task were successful. ERPs demonstrated that in response to visual target stimuli, there was a load-related increase in the posterior slow wave, an index of sustained attention and effort. Importantly, under high load, there was a decrease of the auditory N1 in response to distracters, a marker of early auditory processing. These results suggest that increased WM load is associated with enhanced attentional engagement and protection from distraction in a cross-modal setting, even after controlling for task difficulty and EC. Our findings challenge the classic LT and offer support for alternative models.

Concentration: The Neural Underpinnings of How Cognitive Load Shields Against Distraction

Whether cognitive load—and other aspects of task difficulty—increases or decreases distractibility is subject of much debate in contemporary psychology. One camp argues that cognitive load usurps executive resources, which otherwise could be used for attentional control, and therefore cognitive load increases distraction. The other camp argues that cognitive load demands high levels of concentration (focal-task engagement), which suppresses peripheral processing and therefore decreases distraction. In this article, we employed an functional magnetic resonance imaging (fMRI) protocol to explore whether higher cognitive load in a visually-presented task suppresses task-irrelevant auditory processing in cortical and subcortical areas. The results show that selectively attending to an auditory stimulus facilitates its neural processing in the auditory cortex, and switching the locus-of-attention to the visual modality decreases the neural response in the auditory cortex. When the cognitive load of the task presented in the visual modality increases, the neural response to the auditory stimulus is further suppressed, along with increased activity in networks related to effortful attention. Taken together, the results suggest that higher cognitive load decreases peripheral processing of task-irrelevant information—which decreases distractibility—as a side effect of the increased activity in a focused-attention network.

Increased distractibility in schizotypy: Independent of individual differences in working memory capacity?

Individuals with schizophrenia typically show increased levels of distractibility. This has been attributed to impaired working memory capacity (WMC), since lower WMC is typically associated with higher distractibility, and schizophrenia is typically associated with impoverished WMC. Here, participants performed verbal and spatial serial recall tasks that were accompanied by to-be-ignored speech tokens. For the few trials wherein one speech token was replaced with a different token, impairment was produced to task scores (a deviation effect). Participants subsequently completed a schizotypy questionnaire and a WMC measure. Higher schizotypy scores were associated with lower WMC (as measured with operation span, OSPAN), but WMC and schizotypy scores explained unique variance in relation to the mean magnitude of the deviation effect. These results suggest that schizotypy is associated with heightened domain-general distractibility, but that this is independent of its relationship with WMC.

Background Speech Effects on Sentence Processing during Reading: An Eye Movement Study

Effects of background speech on reading were examined by playing aloud different types of background speech, while participants read long, syntactically complex and less complex sentences embedded in text. Readers’ eye movement patterns were used to study online sentence comprehension. Effects of background speech were primarily seen in rereading time. In Experiment 1, foreign-language background speech did not disrupt sentence processing. Experiment 2 demonstrated robust disruption in reading as a result of semantically and syntactically anomalous scrambled background speech preserving normal sentence-like intonation. Scrambled speech that was constructed from the text to-be read did not disrupt reading more than scrambled speech constructed from a different, semantically unrelated text. Experiment 3 showed that scrambled speech exacerbated the syntactic complexity effect more than coherent background speech, which also interfered with reading. Experiment 4 demonstrated that both semantically and syntactically anomalous speech produced no more disruption in reading than semantically anomalous but syntactically correct background speech. The pattern of results is best explained by a semantic account that stresses the importance of similarity in semantic processing, but not similarity in semantic content, between the reading task and background speech.

Central load reduces peripheral processing: Evidence from incidental memory of background speech

Is there a trade-off between central (working memory) load and peripheral (perceptual) processing? To address this question, participants were requested to undertake an n-back task in one of two levels of central/cognitive load (i.e., 1-back or 2-back) in the presence of a to-be-ignored story presented via headphones. Participants were told to ignore the background story, but they were given a surprise memory test of what had been said in the background story, immediately after the n-back task was completed. Memory was poorer in the high central load (2-back) condition in comparison with the low central load (1-back) condition. Hence, when people compensate for higher central load, by increasing attentional engagement, peripheral processing is constrained. Moreover, participants with high working memory capacity (WMC) - with a superior ability for attentional engagement - remembered less of the background story, but only in the low central load condition. Taken together, peripheral processing - as indexed by incidental memory of background speech - is constrained when task engagement is high.