The Ease of Language Understanding (ELU) model: theoretical, empirical, and clinical advances

Working memory is important for online language processing during conversation. We use it to maintain relevant information, to inhibit or ignore irrelevant information, and to attend to conversation selectively. Working memory helps us to keep track of and actively participate in conversation, including taking turns and following the gist. This paper examines the Ease of Language Understanding model (i.e., the ELU model, Rönnberg, 2003; Rönnberg et al., 2008) in light of new behavioral and neural findings concerning the role of working memory capacity (WMC) in uni-modal and bimodal language processing. The new ELU model is a meaning prediction system that depends on phonological and semantic interactions in rapid implicit and slower explicit processing mechanisms that both depend on WMC albeit in different ways. It is based on findings that address the relationship between WMC and (a) early attention processes in listening to speech, (b) signal processing in hearing aids and its effects on short-term memory, (c) inhibition of speech maskers and its effect on episodic long-term memory, (d) the effects of hearing impairment on episodic and semantic long-term memory, and finally, (e) listening effort. New predictions and clinical implications are outlined. Comparisons with other WMC and speech perception models are made.

Working memory capacity and visual-verbal cognitive load modulate auditory-sensory gating in the brainstem: toward a unified view of attention

Two fundamental research questions have driven attention research in the past: One concerns whether selection of relevant information among competing, irrelevant, information takes place at an early or at a late processing stage; the other concerns whether the capacity of attention is limited by a central, domain-general pool of resources or by independent, modality-specific pools. In this article, we contribute to these debates by showing that the auditory-evoked brainstem response (an early stage of auditory processing) to task-irrelevant sound decreases as a function of central working memory load (manipulated with a visual-verbal version of the n-back task). Furthermore, individual differences in central/domain-general working memory capacity modulated the magnitude of the auditory-evoked brainstem response, but only in the high working memory load condition. The results support a unified view of attention whereby the capacity of a late/central mechanism (working memory) modulates early precortical sensory processing.

ICBEN review of research on the biological effects of noise 2011-2014

The mandate of the International Commission on Biological Effects of Noise (ICBEN) is to promote a high level of scientific research concerning all aspects of noise-induced effects on human beings and animals. In this review, ICBEN team chairs and co-chairs summarize relevant findings, publications, developments, and policies related to the biological effects of noise, with a focus on the period 2011-2014 and for the following topics: Noise-induced hearing loss; nonauditory effects of noise; effects of noise on performance and behavior; effects of noise on sleep; community response to noise; and interactions with other agents and contextual factors. Occupational settings and transport have been identified as the most prominent sources of noise that affect health. These reviews demonstrate that noise is a prevalent and often underestimated threat for both auditory and nonauditory health and that strategies for the prevention of noise and its associated negative health consequences are needed to promote public health.

Hearing impairment, cognition and speech understanding: exploratory factor analyses of a comprehensive test battery for a group of hearing aid users, the n200 study

OBJECTIVE

The aims of the current n200 study were to assess the structural relations between three classes of test variables (i.e. HEARING, COGNITION and aided speech-in-noise OUTCOMES) and to describe the theoretical implications of these relations for the Ease of Language Understanding (ELU) model.

STUDY SAMPLE

Participants were 200 hard-of-hearing hearing-aid users, with a mean age of 60.8 years. Forty-three percent were females and the mean hearing threshold in the better ear was 37.4 dB HL.

DESIGN

LEVEL1 factor analyses extracted one factor per test and/or cognitive function based on a priori conceptualizations. The more abstract LEVEL 2 factor analyses were performed separately for the three classes of test variables.

RESULTS

The HEARING test variables resulted in two LEVEL 2 factors, which we labelled SENSITIVITY and TEMPORAL FINE STRUCTURE; the COGNITIVE variables in one COGNITION factor only, and OUTCOMES in two factors, NO CONTEXT and CONTEXT. COGNITION predicted the NO CONTEXT factor to a stronger extent than the CONTEXT outcome factor. TEMPORAL FINE STRUCTURE and SENSITIVITY were associated with COGNITION and all three contributed significantly and independently to especially the NO CONTEXT outcome scores (R(2) = 0.40).

CONCLUSIONS

All LEVEL 2 factors are important theoretically as well as for clinical assessment.

Who needs cream and sugar when there is eco-labeling? Taste and willingness to pay for "eco-friendly" coffee

Participants tasted two cups of coffee, decided which they preferred, and then rated each coffee. They were told (in lure) that one of the cups contained "eco-friendly" coffee while the other did not, although the two cups contained identical coffee. In Experiments 1 and 3, but not in Experiment 2, the participants were also told which cup contained which type of coffee before they tasted. The participants preferred the taste of, and were willing to pay more for, the "eco-friendly" coffee, at least those who scored high on a questionnaire on attitudes toward sustainable consumer behavior (Experiment 1). High sustainability consumers were also willing to pay more for "eco-friendly" coffee, even when they were told, after their decision, that they preferred the non-labeled alternative (Experiment 2). Moreover, the eco-label effect does not appear to be a consequence of social desirability, as participants were just as biased when reporting the taste estimates and willingness to pay anonymously (Experiment 3). Eco labels not only promote a willingness to pay more for the product but also lead to a more favorable perceptual experience of it.

Episodic long-term memory of spoken discourse masked by speech: what is the role for working memory capacity?

PURPOSE

To investigate whether working memory capacity (WMC) modulates the effects of to-be-ignored speech on the memory of materials conveyed by to-be-attended speech.

METHOD

Two tasks (reading span, Daneman & Carpenter, 1980; Rönnberg et al., 2008; and size-comparison span, Sörqvist, Ljungberg, & Ljung, 2010) were used to measure individual differences in WMC. Episodic long-term memory of spoken discourse was measured by requesting participants to listen to stories masked either by normal speech or by a rotated version of that speech and to subsequently answer questions on the content of the stories.

RESULTS

Normal speech impaired performance on the episodic long-term memory test, and both WMC tasks were negatively related to this effect, indicating that individuals with high WMC are less susceptible to disruption. Moreover, further analyses revealed that size-comparison span (a task that requires resolution of semantic confusion by inhibition processes) is a stronger predictor of the effect than is reading span.

CONCLUSIONS

Cognitive control processes support listening in adverse conditions. In particular, inhibition processes acting to resolve semantic confusion seem to underlie the relationship between WMC and susceptibility to distraction from masking speech.

Effects of speech on proofreading: can task-engagement manipulations shield against distraction?

This article reports 2 experiments that examine techniques to shield against the potentially disruptive effects of task-irrelevant background speech on proofreading. The participants searched for errors in texts that were either normal (i.e., written in Times New Roman font) or altered (i.e., presented either in Haettenschweiler font or in Times New Roman but masked by visual noise) in 2 sound conditions: a silent condition and a condition with background speech. Proofreading for semantic/contextual errors was impaired by speech, but only when the text was normal. This effect of speech was completely abolished when the text was written in an altered font (Experiment 1) or when it was masked by visual noise (Experiment 2). There was no functional difference between the 2 ways to alter the text with regard to the way the manipulations influenced the effects of background speech on proofreading. The results indicate that increased task demands, which lead to greater focal-task engagement, may shield against the distracting effects of background speech on proofreading.

Disruption of writing processes by the semanticity of background speech

Previous studies have noted that writing processes are impaired by task-irrelevant background sound. However, what makes sound distracting to writing processes has remained unaddressed. The experiment reported here investigated whether the semanticity of irrelevant speech contributes to disruption of writing processes beyond the acoustic properties of the sound. The participants wrote stories against a background of normal speech, spectrally-rotated speech (i.e., a meaningless sound with marked acoustic resemblance to speech) or silence. Normal speech impaired quantitative (e.g., number of characters produced) and qualitative/semantic (e.g., uncorrected typing errors, proposition generation) aspects of the written material, in comparison with the other two sound conditions, and it increased the duration of pauses between words. No difference was found between the silent and the rotated-speech condition. These results suggest that writing is susceptible to disruption from the semanticity of speech but not especially susceptible to disruption from the acoustic properties of speech.

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.

How Concentration Shields Against Distraction

In this article, we outline our view of how concentration shields against distraction. We argue that higher levels of concentration make people less susceptible to distraction for two reasons. One reason is that the undesired processing of the background environment is reduced. For example, when people play a difficult video game, as opposed to an easy game, they are less likely to notice what people in the background are saying. The other reason is that the locus of attention becomes more steadfast. For example, when people are watching an entertaining episode of their favorite television series, as opposed to a less absorbing show, attention is less likely to be diverted away from the screen by a ringing telephone. The theoretical underpinnings of this perspective, and potential implications for applied settings, are addressed.

Individual differences in distractibility: An update and a model

This paper reviews the current literature on individual differences in susceptibility to the effects of background sound on visual-verbal task performance. A large body of evidence suggests that individual differences in working memory capacity (WMC) underpin individual differences in susceptibility to auditory distraction in most tasks and contexts. Specifically, high WMC is associated with a more steadfast locus of attention (thus overruling the call for attention that background noise may evoke) and a more constrained auditory-sensory gating (i.e., less processing of the background sound). The relation between WMC and distractibility is a general framework that may also explain distractibility differences between populations that differ along variables that covary with WMC (such as age, developmental disorders, and personality traits). A neurocognitive task-engagement/distraction trade-off (TEDTOFF) model that summarizes current knowledge is outlined and directions for future research are proposed.

Experts on age estimation

The aim of this investigation was to study the biases and accuracy in age estimation of persons selling alcohol. Two experiments are reported, both suggesting that the accuracy in age estimation of Swedish alcohol salespersons is higher than that of control persons. This expertise in age estimation is probably the result of the extensive training Swedish alcohol salespersons go through as a natural part of their profession. Nonetheless, their estimates were not free from bias. Salespersons overestimated the age of target persons below 20 years of age and thus too young to buy alcohol. The results also revealed that controls, in contrast to salespersons, assimilated their estimates towards their own age (i.e. an own-anchor effect). Furthermore, female participants were shown to estimate the age of old target persons (56-65 years) more accurately than male participants. These results are discussed in relation to previous findings on training in age estimation and present jurisdiction.

A 3 year update on the influence of noise on performance and behavior

The effect of noise exposure on human performance and behavior continues to be a focus for research activities. This paper reviews developments in the field over the past 3 years, highlighting current areas of research, recent findings, and ongoing research in two main research areas: Field studies of noise effects on children's cognition and experimental studies of auditory distraction. Overall, the evidence for the effects of external environmental noise on children's cognition has strengthened in recent years, with the use of larger community samples and better noise characterization. Studies have begun to establish exposure-effect thresholds for noise effects on cognition. However, the evidence remains predominantly cross-sectional and future research needs to examine whether sound insulation might lessen the effects of external noise on children's learning. Research has also begun to explore the link between internal classroom acoustics and children's learning, aiming to further inform the design of the internal acoustic environment. Experimental studies of the effects of noise on cognitive performance are also reviewed, including functional differences in varieties of auditory distraction, semantic auditory distraction, individual differences in susceptibility to auditory distraction, and the role of cognitive control on the effects of noise on understanding and memory of target speech materials. In general, the results indicate that there are at least two functionally different types of auditory distraction: One due to the interruption of processes (as a result of attention being captured by the sound), another due to interference between processes. The magnitude of the former type is related to individual differences in cognitive control capacities (e.g., working memory capacity); the magnitude of the latter is not. Few studies address noise effects on behavioral outcomes, emphasizing the need for researchers to explore noise effects on behavior in more detail.

The role of working memory capacity in auditory distraction: a review

The purpose of this paper was to review the current knowledge on individual differences in susceptibility to the effects of task-irrelevant sound on cognition. The literature indicates that at least two functionally different cognitive mechanisms underlie those differences; one is the efficiency by which people process the order between perceptually discrete sound events and the other is related to working memory capacity. The first mechanism seems to be involved only when disruption is a function of conflicting order processes, whereas the other mechanism is involved in a wider range of phenomena including those when attentional capture and conflicting semantic processes form the basis of disruption. Because of this, noise abatement interventions should first of all be directed towards people with low working memory capacity. Implications for theories of auditory distraction are discussed.

Effects of road traffic noise and irrelevant speech on children's reading and mathematical performance

Irrelevant speech in classrooms and road traffic noise adjacent to schools have a substantial impact on children's ability to learn. Comparing the effects of different noise sources on learning may help construct guidelines for noise abatement programs. Experimental studies are important to establish dose-response relationships and to expand our knowledge beyond correlation studies. This experiment examined effects of road traffic noise and irrelevant speech on children's reading speed, reading comprehension, basic mathematics, and mathematical reasoning. A total of 187 pupils (89 girls and 98 boys), 12-13 years old, were tested in their ordinary classrooms. Road traffic noise was found to impair reading speed (P<0.01) and basic mathematics (P<0.05). No effect was found on reading comprehension or on mathematical reasoning. Irrelevant speech did not disrupt performance on any task. These findings are related to previous research on noise in schools and the implications for noise abatement guidelines are discussed.

Psychological Restoration Can Depend on Stimulus-Source Attribution: A Challenge for the Evolutionary Account?

Visiting or viewing nature environments can have restorative psychological effects, while exposure to the built environment typically has less positive effects. A classic view is that this difference in restorative potential of nature and built environments depends on differences in the intrinsic characteristics of the stimuli. In addition, an evolutionary account is often assumed whereby restoration is believed to be a hardwired response to nature’s stimulus-features. Here, we propose the novel hypothesis that the restorative effects of a stimulus do not entirely depend on the stimulus-features per se, but also on the meaning that people assign to the stimulus. Participants conducted cognitively demanding tests prior to and after a brief pause. During the pause, the participants were exposed to an ambiguous sound consisting of pink noise with white noise interspersed. Participants in the “nature sound-source condition” were told that the sound originated from a nature scene with a waterfall; participants in the “industrial sound-source condition” were told that the sound originated from an industrial environment with machinery; and participants in the “control condition” were told nothing about the sound origin. Self-reported mental exhaustion showed that participants in the nature sound-source condition were more psychologically restored after the pause than participants in the industrial sound-source condition. One potential interpretation of the results is that restoration from nature experiences depends on learned, positive associations with nature; not only on hardwired responses shaped by evolution.

Expectations modulate the magnitude of attentional capture by auditory events

What determines the magnitude of attentional capture by deviant sound events? We combined the cross-modal oddball distraction paradigm with sequence learning to address this question. Participants responded to visual targets, each preceded by tones that formed a repetitive cross-trial standard sequence. In Experiment 1, with the standard tone sequence …-660-440-660-880-… Hz, either the 440 Hz or the 880 Hz standard was occasionally replaced by one of two deviant tones (220 Hz and 1100 Hz), that either differed slightly (by 220 Hz) or markedly (by 660 Hz) from the replaced standard. In Experiment 2, with the standard tone sequence …-220-660-440-660-880-660-1100-… Hz, the 440 Hz and the 880 Hz standard was occasionally replaced by either a 220 Hz or a 1100 Hz pattern deviant. In both experiments, a high-pitch deviant was more captivating when it replaced a low-pitch standard, and a low-pitch deviant was more captivating when it replaced a high-pitch standard. These results indicate that the magnitude of attentional capture by deviant sound events depends on the discrepancy between the deviant event and the expected event, not on perceived local change.

Why People Harm the Environment Although They Try to Treat It Well: An Evolutionary-Cognitive Perspective on Climate Compensation

Anthropogenic climate changes stress the importance of understanding why people harm the environment despite their attempts to behave in climate friendly ways. This paper argues that one reason behind why people do this is that people apply heuristics, originally shaped to handle social exchange, on the issues of environmental impact. Reciprocity and balance in social relations have been fundamental to social cooperation, and thus to survival, and therefore the human brain has become specialized by natural selection to compute and seek this balance. When the same reasoning is applied to environment-related behaviors, people tend to think in terms of a balance between “environmentally friendly” and “harmful” behaviors, and to morally account for the average of these components rather than the sum. This balancing heuristic leads to compensatory green beliefs and negative footprint illusions—the misconceptions that “green” choices can compensate for unsustainable ones. “Eco-guilt” from imbalance in the moral environmental account may promote pro-environmental acts, but also acts that are seemingly pro-environmental but in reality more harmful than doing nothing at all. Strategies for handling problems caused by this cognitive insufficiency are discussed.

Office noise: Can headphones and masking sound attenuate distraction by background speech?

BACKGROUND

Background speech is one of the most disturbing noise sources at shared workplaces in terms of both annoyance and performance-related disruption. Therefore, it is important to identify techniques that can efficiently protect performance against distraction. It is also important that the techniques are perceived as satisfactory and are subjectively evaluated as effective in their capacity to reduce distraction.

OBJECTIVE

The aim of the current study was to compare three methods of attenuating distraction from background speech: masking a background voice with nature sound through headphones, masking a background voice with other voices through headphones and merely wearing headphones (without masking) as a way to attenuate the background sound. Quiet was deployed as a baseline condition.

METHODS

Thirty students participated in an experiment employing a repeated measures design.

RESULTS

Performance (serial short-term memory) was impaired by background speech (1 voice), but this impairment was attenuated when the speech was masked - and in particular when it was masked by nature sound. Furthermore, perceived workload was lowest in the quiet condition and significantly higher in all other sound conditions. Notably, the headphones tested as a sound-attenuating device (i.e. without masking) did not protect against the effects of background speech on performance and subjective work load.

CONCLUSIONS

Nature sound was the only masking condition that worked as a protector of performance, at least in the context of the serial recall task. However, despite the attenuation of distraction by nature sound, perceived workload was still high - suggesting that it is difficult to find a masker that is both effective and perceived as satisfactory.

When A+B < A: Cognitive Bias in Experts' Judgment of Environmental Impact

When 'environmentally friendly' items are added to a set of conventional items, people report that the total set will have a lower environmental impact even though the actual impact increases. One hypothesis is that this "negative footprint illusion" arises because people, who are susceptible to the illusion, lack necessary knowledge of the item's actual environmental impact, perhaps coupled with a lack of mathematical skills. The study reported here addressed this hypothesis by recruiting participants ('experts') from a master's program in energy systems, who thus have bachelor degrees in energy-related fields including academic training in mathematics. They were asked to estimate the number of trees needed to compensate for the environmental burden of two sets of buildings: one set of 150 buildings with conventional energy ratings and one set including the same 150 buildings but also 50 'green' (energy-efficient) buildings. The experts reported that less trees were needed to compensate for the set with 150 conventional and 50 'green' buildings compared to the set with only the 150 conventional buildings. This negative footprint illusion was as large in magnitude for the experts as it was for a group of novices without academic training in energy-related fields. We conclude that people are not immune to the negative footprint illusion even when they have the knowledge necessary to make accurate judgments.