Auditory distraction in young and middle-aged adults: a behavioural and event-related potential study

The Effects of Total Sleep Deprivation on Attention Capture Processes in Young and Older Adults: An ERP Study

BACKGROUND

The present study investigated whether sleep deprivation affects attention capture in young and older adults using event-related potentials (ERPs).

METHODS

Eleven young adults (20-30 y) and nine older adults (60-70 y) were tested following both normal sleep (NS) and total sleep deprivation (TSD). ERPs were recorded during an auditory discrimination task consisting of standard and deviant stimuli.

RESULTS

Deviant stimuli elicited the MMN, P3a, and RON ERPs. TSD attenuated the differences in reaction times between standards and deviants in young adults but not older adults. The P3a was attenuated in older adults compared to young adults. Older adults had a larger RON amplitude compared to young adults following NS, but not TSD.

CONCLUSIONS

The reduced P3a and the absence of behavioral performance alteration in the older group suggests that older adults may utilize different neural processing strategies compared to younger adults to compensate for age-related declines in neural resources for attention capture. Sleep loss influenced age-related differences on the RON, suggesting that older adults may have reduced access to compensatory strategies following sleep loss.

Age-related differences in bottom-up and top-down attention: Insights from EEG and MEG

Attention operates through top‐down and bottom‐up processes, and a balance between these processes is crucial for daily tasks. Imperilling such balance could explain ageing‐associated attentional problems such as exacerbated distractibility. In this study, we aimed to characterize this enhanced distractibility by investigating the impact of ageing upon event‐related components associated with top‐down and bottom‐up attentional processes. MEG and EEG data were acquired from 14 older and 14 younger healthy adults while performing a task that conjointly evaluates top‐down and bottom‐up attention. Event‐related components were analysed on sensor and source levels. In comparison with the younger group, the older mainly displayed (1) reduced target anticipation processes (reduced CMV), (2) increased early target processing (larger P50 but smaller N1) and (3) increased processing of early distracting sounds (larger N1 but reduced P3a), followed by a (4) prolonged reorientation towards the main task (larger RON). Taken together, our results suggest that the enhanced distractibility in ageing could stem from top‐down deficits, in particular from reduced inhibitory and reorientation processes.

A cognitive model of response omissions in distraction paradigms

The effects of distraction on responses manifest in three ways: prolonged reaction times, and increased error and response omission rates. However, the latter effect is often ignored or assumed to be due to a separate cognitive process. We investigated omissions occurring in two paradigms that manipulated distraction. One required simple stimulus detection of younger participants, the second required choice responses and was completed by both younger and older participants. We fit data from these paradigms with a model that identifies three causes of omissions: two are related to the process of accumulating the evidence on which a response is based: intrinsic omissions (due to between-trial variation in accumulation rates making it impossible to ever reach the evidence threshold) and design omissions (due to response windows that cause slow responses not to be recorded; a third, contaminant omissions, allows for a cause unrelated to the response process. In both data sets systematic differences in omission rates across conditions were accounted for by task-related omissions. Intrinsic omissions played a lesser role than design omissions, even though the presence of design omissions was not evident in descriptive analyses of the data. The model provided an accurate account of all aspects of the detection data and the choice-response data, but slightly underestimated overall omissions in the choice paradigm, particularly in older participants, suggesting that further investigation of contaminant omission effects is needed.

N-methyl-d-aspartate receptor antagonism modulates P300 event-related potentials and associated activity in salience and central executive networks

Impairments in auditory information processing in schizophrenia as indexed electrophysiologically by P300 deficits during novelty (P3a) and target (P3b) processing are linked to N -methyl- D -aspartate receptor (NMDAR) dysfunction. This study in 14 healthy volunteers examined the effects of a subanesthetic dose of the NMDAR antagonist ketamine on P300 and their relationship to psychomimetic symptoms and cortical source activity (with eLORETA). Ketamine reduced early (e- P3a) and late (l-P3a) novelty P300 at sensor (scalp)-level and at source-level in the salience network. Increases in dissociation symptoms were negatively correlated with ketamine-induced P3b changes, at sensor-level and source-level, in both salience and central executive networks. These P3a alterations during novelty processing, and the symptom-related P3b changes during target processing support a model of NMDAR hypofunction underlying disrupted auditory attention in schizophrenia.

Aging Increases Cross-Modal Distraction by Unexpected Sounds: Controlling for Response Speed

It is well-established that task-irrelevant sounds deviating from an otherwise predictable auditory sequence capture attention and disrupt ongoing performance by delaying responses in the ongoing task. In visual tasks, larger distraction by unexpected sounds (deviance distraction) has been reported in older than in young adults. However, past studies based this conclusion on the comparisons of absolute response times (RT) and did not control for the general slowing typically observed in older adults. Hence, it remains unclear whether this difference in deviance distraction between the two age groups reflects a genuine effect of aging or a proportional effect of similar size in both groups. We addressed this issue by using a proportional measure of distraction (PMD) to reanalyze the data from four past studies and used Bayesian estimation to generate credible estimates of the age-related difference in deviance distraction and its effect size. The results were unambiguous: older adults exhibited greater deviance distraction than young adults when controlling for baseline response speed (in each individual study and in the combined data set). Bayesian estimation revealed a proportional lengthening of RT by unexpected sounds that was about twice as large in older than in young adults (corresponding to a large statistical effect size). A similar analysis was carried out on the proportion of correct responses (PC) and produced converging results. Finally, an additional Bayesian analysis comparing data from cross-modal and uni-modal studies confirmed the selective effect of aging on distraction in the first and not the second. Overall, our study shows that older adults performing a visual categorization task do exhibit greater distraction by unexpected sounds than young adults and that this effect is not explicable by age-related general slowing.

Postural Control While Listening in Younger and Middle-Aged Adults

OBJECTIVES

The motivation for this research is to determine whether a listening-while-balancing task would be sensitive to quantifying listening effort in middle age. The premise behind this exploratory work is that a decrease in postural control would be demonstrated in challenging acoustic conditions, more so in middle-aged than in younger adults.

DESIGN

A dual-task paradigm was employed with speech understanding as one task and postural control as the other. For the speech perception task, participants listened to and repeated back sentences in the presence of other sentences or steady-state noise. Targets and maskers were presented in both spatially-coincident and spatially-separated conditions. The postural control task required participants to stand on a force platform either in normal stance (with feet approximately shoulder-width apart) or in tandem stance (with one foot behind the other). Participants also rated their subjective listening effort at the end of each block of trials.

RESULTS

Postural control was poorer for both groups of participants when the listening task was completed at a more adverse (vs. less adverse) signal-to-noise ratio. When participants were standing normally, postural control in dual-task conditions was negatively associated with degree of high-frequency hearing loss, with individuals who had higher pure-tone thresholds exhibiting poorer balance. Correlation analyses also indicated that reduced speech recognition ability was associated with poorer postural control in both single- and dual-task conditions. Middle-aged participants exhibited larger dual-task costs when the masker was speech, as compared to when it was noise. Individuals who reported expending greater effort on the listening task exhibited larger dual-task costs when in normal stance.

CONCLUSIONS

Listening under challenging acoustic conditions can have a negative impact on postural control, more so in middle-aged than in younger adults. One explanation for this finding is that the increased effort required to successfully listen in adverse environments leaves fewer resources for maintaining balance, particularly as people age. These results provide preliminary support for using this type of ecologically-valid dual-task paradigm to quantify the costs associated with understanding speech in adverse acoustic environments.

Human Brain Ages With Hierarchy-Selective Attenuation of Prediction Errors

From the perspective of predictive coding, our brain embodies a hierarchical generative model to realize perception, which proactively predicts the statistical structure of sensory inputs. How are these predictive processes modified as we age? Recent research suggested that aging leads to decreased weighting of sensory inputs and increased reliance on predictions. Here we investigated whether this age-related shift from sensorium to predictions occurs at all levels of hierarchical message passing. We recorded the electroencephalography responses with an auditory local-global paradigm in a cohort of 108 healthy participants from 3 groups: seniors, adults, and adolescents. The detection of local deviancy seems largely preserved in older individuals at earlier latency (including the mismatch negativity followed by the P3a but not the reorienting negativity). In contrast, the detection of global deviancy is clearly compromised in older individuals, as they showed worse task performance and attenuated P3b. Our findings demonstrate that older brains show little decline in sensory (i.e., first-order) prediction errors but significant diminution in contextual (i.e., second-order) prediction errors. Age-related deficient maintenance of auditory information in working memory might affect whether and how lower-level prediction errors propagate to the higher level.

Brain aging and speech perception: Effects of background noise and talker variability

Speech perception can be challenging, especially for older adults. Despite the importance of speech perception in social interactions, the mechanisms underlying these difficulties remain unclear and treatment options are scarce. While several studies have suggested that decline within cortical auditory regions may be a hallmark of these difficulties, a growing number of studies have reported decline in regions beyond the auditory processing network, including regions involved in speech processing and executive control, suggesting a potentially diffuse underlying neural disruption, though no consensus exists regarding underlying dysfunctions. To address this issue, we conducted two experiments in which we investigated age differences in speech perception when background noise and talker variability are manipulated, two factors known to be detrimental to speech perception. In Experiment 1, we examined the relationship between speech perception, hearing and auditory attention in 88 healthy participants aged 19 to 87 years. In Experiment 2, we examined cortical thickness and BOLD signal using magnetic resonance imaging (MRI) and related these measures to speech perception performance using a simple mediation approach in 32 participants from Experiment 1. Our results show that, even after accounting for hearing thresholds and two measures of auditory attention, speech perception significantly declined with age. Age-related decline in speech perception in noise was associated with thinner cortex in auditory and speech processing regions (including the superior temporal cortex, ventral premotor cortex and inferior frontal gyrus) as well as in regions involved in executive control (including the dorsal anterior insula, the anterior cingulate cortex and medial frontal cortex). Further, our results show that speech perception performance was associated with reduced brain response in the right superior temporal cortex in older compared to younger adults, and to an increase in response to noise in older adults in the left anterior temporal cortex. Talker variability was not associated with different activation patterns in older compared to younger adults. Together, these results support the notion of a diffuse rather than a focal dysfunction underlying speech perception in noise difficulties in older adults.

Age Effects on Distraction in a Visual Task Requiring Fast Reactions: An Event-Related Potential Study

We investigated the effects of distractors in older and younger participants in choice and simple reaction time tasks with concurrent registration of event-related potentials. In the task the participants had to prevent a disk from falling into a bin after a color or luminosity change (target stimuli). Infrequently, task-irrelevant stimuli (schematic faces or threatening objects) were superimposed on the target stimuli (distractors), or the bin disappeared which required no response (Nogo trials). Reaction time was delayed to the distractors, but this effect was similar in the two age groups. As a robust age-related difference, in the older group a large anterior positivity and posterior negativity emerged to the distractors within the 100-200 ms post-stimulus range, and these components were larger for schematic faces than for threatening objects. sLORETA localized the age-specific effect to the ventral stream of the visual system and to anterior structures considered as parts of the executive system. The Nogo stimuli elicited a late positivity (Nogo P3) with longer latency in the older group. We interpreted the age-related differences as decreased but compensated resistance to task-irrelevant change of the target stimuli.

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.

Increased Amplitude of the P3a ERP Component as a Neurocognitive Marker for Differentiating Amnestic Subtypes of Mild Cognitive Impairment

The event-related potential (ERP) technique has been shown to be useful for evaluating changes in brain electrical activity associated with different cognitive processes, particularly in Alzheimer's disease (AD). Longitudinal studies have shown that a high proportion of people with amnestic mild cognitive impairment (aMCI) go on to develop AD. aMCI is divided into two subtypes according to the presence of memory impairment only (single-domain aMCI: sdaMCI) or impairment of memory and other cognitive domains (multi-domain aMCI: mdaMCI). The main aim of this study was to examine the effects of sdaMCI and mdaMCI on the P3a ERP component associated with the involuntary orientation of attention toward unattended infrequent novel auditory stimuli. Participants performed an auditory-visual distraction-attention task, in which they were asked to ignore the auditory stimuli (standard, deviant, and novel) and to attend to the visual stimuli (responding to some of them: Go stimuli). P3a was identified in the Novel minus Standard difference waveforms, and reaction times (RTs) and hits (in response to Go stimuli) were also analyzed. Participants were classified into three groups: Control, 20 adults (mean age (M): 65.8 years); sdaMCI, 19 adults (M: 67 years); and mdaMCI, 11 adults (M: 71 years). In all groups, the RTs were significantly longer when Go stimuli were preceded by novel (relative to standard) auditory stimuli, suggesting a distraction effect triggered by novel stimuli; mdaMCI participants made significantly fewer hits than control and sdaMCI participants. P3a comprised two consecutive phases in all groups: early-P3a (e-P3a), which may reflect the orienting response toward the irrelevant stimuli, and late-P3a (l-P3a), which may be a correlate of subsequent evaluation of these stimuli. The e-P3a amplitude was significantly larger in mdaMCI than in sdaMCI participants, and the l-P3a amplitude was significantly larger in mdaMCI than in sdaMCI and Control participants, indicating greater involuntary capture of attention to unattended novel auditory stimuli and allocation of more attentional resources for the subsequent evaluation of these stimuli in mdaMCI participants. The e-P3a and l-P3a components showed moderate to high sensitivity and specificity for distinguishing between groups, suggesting that both may represent optimal neurocognitive markers for differentiating aMCI subtypes.

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.

The Orienting Response in Healthy Aging: Novelty P3 Indicates No General Decline but Reduced Efficacy for Fast Stimulation Rates

Automatic orienting to unexpected changes in the environment is a pre-requisite for adaptive behavior. One prominent mechanism of automatic attentional control is the Orienting Response (OR). Despite the fundamental significance of the OR in everyday life, only little is known about how the OR is affected by healthy aging. We tested this question in two age groups (19-38 and 55-72 years) and measured skin-conductance responses (SCRs) and event-related brain potentials (ERPs) to novels (i.e., short environmental sounds presented only once in the experiment; 10% of the trials) compared to standard sounds (600 Hz sinusoidal tones with 200 ms duration; 90% of the trials). Novel and standard stimuli were presented in four conditions differing in the inter-stimulus interval (ISI) with a mean ISI of either 10, 3, 1, or 0.5 s (blocked presentation). In both age groups, pronounced SCRs were elicited by novels in the 10 s ISI condition, suggesting the elicitation of stable ORs. These effects were accompanied by pronounced N1 and frontal P3 amplitudes in the ERP, suggesting that automatic novelty processing and orientation of attention are effective in both age groups. Furthermore, the SCR and ERP effects declined with decreasing ISI length. In addition, differences between the two groups were observable with the fastest presentation rates (i.e., 1 and 0.5 s ISI length). The most prominent difference was a shift of the peak of the frontal positivity from around 300 to 200 ms in the 19-38 years group while in the 55-72 years group the amplitude of the frontal P3 decreased linearly with decreasing ISI length. Taken together, this pattern of results does not suggest a general decline in processing efficacy with healthy aging. At least with very rare changes (here, the novels in the 10 s ISI condition) the OR is as effective in healthy older adults as in younger adults. With faster presentation rates, however, the efficacy of the OR decreases. This seems to result in a switch from novelty to deviant processing in younger adults, but less so in the group of older adults.

Involuntary Capture and Voluntary Reorienting of Attention Decline in Middle-Aged and Old Participants

The main aim of this study was to examine the effects of aging on event-related brain potentials (ERPs) associated with the automatic detection of unattended infrequent deviant and novel auditory stimuli (Mismatch Negativity, MMN) and with the orienting to these stimuli (P3a component), as well as the effects on ERPs associated with reorienting to relevant visual stimuli (Reorienting Negativity, RON). Participants were divided into three age groups: (1) Young: 21-29 years old; (2) Middle-aged: 51-64 years old; and (3) Old: 65-84 years old. They performed an auditory-visual distraction-attention task in which they were asked to attend to visual stimuli (Go, NoGo) and to ignore auditory stimuli (S: standard, D: deviant, N: novel). Reaction times (RTs) to Go visual stimuli were longer in old and middle-aged than in young participants. In addition, in all three age groups, longer RTs were found when Go visual stimuli were preceded by novel relative to deviant and standard auditory stimuli, indicating a distraction effect provoked by novel stimuli. ERP components were identified in the Novel minus Standard (N-S) and Deviant minus Standard (D-S) difference waveforms. In the N-S condition, MMN latency was significantly longer in middle-aged and old participants than in young participants, indicating a slowing of automatic detection of changes. The following results were observed in both difference waveforms: (1) the P3a component comprised two consecutive phases in all three age groups-an early-P3a (e-P3a) that may reflect the orienting response toward the irrelevant stimulation and a late-P3a (l-P3a) that may be a correlate of subsequent evaluation of the infrequent unexpected novel or deviant stimuli; (2) the e-P3a, l-P3a, and RON latencies were significantly longer in the Middle-aged and Old groups than in the Young group, indicating delay in the orienting response to and the subsequent evaluation of unattended auditory stimuli, and in the reorienting of attention to relevant (Go) visual stimuli, respectively; and (3) a significantly smaller e-P3a amplitude in Middle-aged and Old groups, indicating a deficit in the orienting response to irrelevant novel and deviant auditory stimuli.

The ultra-slow NAT2*6A haplotype is associated with reduced higher cognitive functions in an elderly study group

N-Acetyltransferase 2 (NAT2) genotype is associated with age-related declines in basic sensory hearing functions. However, the possible modulatory role of NAT2 for higher cognitive functions has not yet been studied. We tested auditory goal-directed behavior and attentional control in 120 NAT2 genotyped subjects (63-88 years), using an auditory distraction paradigm in which participants responded to the duration of long and short tone stimuli. We studied involuntary shifts in attention to task-irrelevant deviant stimuli and applied event-related potentials (ERPs) to examine which cognitive subprocesses are affected by NAT2 status on a neurophysiological level. Relative to the standard stimuli, deviant stimuli decreased performance in the recently described ultra-slow acetylators (NAT2*6A and *7B): The increase in error-corrected reaction times (a combined measure of response speed and accuracy) in ultra-slow acetylators (254 ms increase) was more than twice as high as in the rapid acetylator reference group (111 ms increase; p < 0.01). The increase was still higher than in the other slow acetylators (149 ms increase, p < 0.05). In addition, clear differences were found in the ERP results: Ultra-slow acetylators showed deficits specifically in the automatic detection of changes in the acoustic environment as evidenced by reduced mismatch negativity (MMN, p < 0.005 compared to rapid acetylators). Refocussing of attention after a distracting event was also impaired in the ultra-slow acetylators as evidenced by a reduced re-orienting negativity (RON, p < 0.01 compared to rapid acetylators). In conclusion, the ultra-slow acetylation status was associated with reduced higher cognitive functions.

Effects of aging and involuntary capture of attention on event-related potentials associated with the processing of and the response to a target stimulus

The main aim of the present study was to assess whether aging modulates the effects of involuntary capture of attention by novel stimuli on performance, and on event-related potentials (ERPs) associated with target processing (N2b and P3b) and subsequent response processes (stimulus-locked Lateralized Readiness Potential -sLRP- and response-locked Lateralized Readiness Potential -rLRP-). An auditory-visual distraction-attention task was performed by 77 healthy participants, divided into three age groups (Young: 21-29, Middle-aged: 51-64, Old: 65-84 years old). Participants were asked to attend to visual stimuli and to ignore auditory stimuli. Aging was associated with slowed reaction times, target stimulus processing in working memory (WM, longer N2b and P3b latencies) and selection and preparation of the motor response (longer sLRP and earlier rLRP onset latencies). In the novel relative to the standard condition we observed, in the three age groups: (1) a distraction effect, reflected in a slowing of reaction times, of stimuli categorization in WM (longer P3b latency), and of motor response selection (longer sLRP onset latency); (2) a facilitation effect on response preparation (later rLRP onset latency), and (3) an increase in arousal (larger amplitudes of all ERPs evaluated, except for N2b amplitude in the Old group). A distraction effect on the stimulus evaluation processes (longer N2b latency) were also observed, but only in middle-aged and old participants, indicating that the attentional capture slows the stimulus evaluation in WM from early ages (from 50 years onwards, without differences between middle-age and older adults), but not in young adults.

Neuro-Behavioral Correlates of Post-Deviance Distraction in Middle-Aged and Old Adults

The presentation of a task-irrelevant deviant (novel) stimulus among otherwise repeated standard stimuli usually reduces performance not only for the deviant stimulus, but also for the standard following that deviant. Here, the so-called post-deviance distraction was investigated in 58 middle-aged and 52 old adults, using an auditory duration discrimination task and event-related potential (ERP) measures. After a deviant stimulus, the participants showed a decrease in performance in the subsequent standard stimulus. This effect was more pronounced in the old, than middle-aged, group. Relative to the standard stimuli preceding the deviant, post-deviant standards triggered a chain of mismatch negativity (MMN), P3a, and reorienting negativity (RON). While MMN and P3a did not differ in old and middle-aged adults, older participants showed a delayed RON. Assuming the RON to reflect processes of general task or feature reconfiguration and updating, these results suggest a delay in orienting-reorienting mechanisms as possible source of increased post-deviance distraction in elderly.

Predictability effects in auditory scene analysis: a review

Many sound sources emit signals in a predictable manner. The idea that predictability can be exploited to support the segregation of one source's signal emissions from the overlapping signals of other sources has been expressed for a long time. Yet experimental evidence for a strong role of predictability within auditory scene analysis (ASA) has been scarce. Recently, there has been an upsurge in experimental and theoretical work on this topic resulting from fundamental changes in our perspective on how the brain extracts predictability from series of sensory events. Based on effortless predictive processing in the auditory system, it becomes more plausible that predictability would be available as a cue for sound source decomposition. In the present contribution, empirical evidence for such a role of predictability in ASA will be reviewed. It will be shown that predictability affects ASA both when it is present in the sound source of interest (perceptual foreground) and when it is present in other sound sources that the listener wishes to ignore (perceptual background). First evidence pointing toward age-related impairments in the latter capacity will be addressed. Moreover, it will be illustrated how effects of predictability can be shown by means of objective listening tests as well as by subjective report procedures, with the latter approach typically exploiting the multi-stable nature of auditory perception. Critical aspects of study design will be delineated to ensure that predictability effects can be unambiguously interpreted. Possible mechanisms for a functional role of predictability within ASA will be discussed, and an analogy with the old-plus-new heuristic for grouping simultaneous acoustic signals will be suggested.

Long-term cardiovascular fitness is associated with auditory attentional control in old adults: neuro-behavioral evidence

It has been shown that healthy aging affects the ability to focus attention on a given task and to ignore distractors. Here, we asked whether long-term physical activity is associated with lower susceptibility to distraction of auditory attention, and how physically active and inactive seniors may differ regarding subcomponents of auditory attention. An auditory duration discrimination task was employed, and involuntary attentional shifts to task-irrelevant rare frequency deviations and subsequent reorientation were studied by analysis of behavioral data and event-related potential measures. The frequency deviations impaired performance more in physically inactive than active seniors. This was accompanied by a stronger frontal positivity (P3a) and increased activation of anterior cingulate cortex, suggesting a stronger involuntary shift of attention towards task-irrelevant stimulus features in inactive compared to active seniors. These results indicate a positive relationship between physical fitness and attentional control in elderly, presumably due to more focused attentional resources and enhanced inhibition of irrelevant stimulus features.

The dissociation between the P3a event-related potential and behavioral distraction

Unexpected novel sounds can capture our attention and impair performance. Recent behavioral research revealed that only novel sounds that provided target-related (but not task-related) information impaired performance. This poses the question of the automaticity of novelty processing and its expression at the behavioral level. In an auditory-visual oddball paradigm, the informational content of sounds regarding the time and probability of target occurrence was varied. Independent from the informational content, novel, and deviant sounds elicited the P3a, an ERP-component related to novelty processing. In contrast, impaired performance was only observed if target-related information was provided. Results indicate that distractor sounds are automatically evaluated as potentially significant, but that the consequences for behavior depend on further processes such as the processing of the given information.

Behavioral Distraction by Auditory Deviance Is Mediated by the Sound’s Informational Value *Li and Parmentier share the first authorship of this study

Sounds deviating from an otherwise repetitive background in some task-irrelevant respect (deviant sounds among standard sounds) capture attention in an obligatory fashion and result in behavioral distraction in an ongoing task. Traditionally, such distraction has been considered as the ineluctable consequence of the deviant sound’s low probability of occurrence relative to that of the standard. Recent evidence from a cross-modal oddball task challenged this idea by showing that deviant sounds only yield distraction in a visual task when auditory distractors (standards and deviants) announce with certainty the imminent presentation of a target stimulus (event information), regardless of whether they predict the target’s temporal onset (temporal information). The present study sought to test for the first time whether this finding may be generalized to a purely auditory oddball task in which distractor and target information form part of the same perceptual stimulus. Participants were asked to judge whether a sound starting from a central location moved left or right while ignoring rare and unpredictable changes in the sound’s identity. By manipulating the temporal and probabilistic relationship between sound onset and movement onset, we disentangled the roles of event and temporal information and found that, as in the auditory-visual oddball task, deviance distraction is mediated by the extent to which distractor information harbingers the presentation of the target information (event information). This finding suggests that the provision of event information by auditory distractors is a fundamental prerequisite of behavioral deviance distraction.

Does age increase auditory distraction? Electrophysiological correlates of high and low performance in seniors

Aging usually affects the ability to focus attention on a given task and to ignore distractors. However, aging is also associated with increased between-subject variability, and it is unclear in which features of processing older high-performing and low-performing human beings may differ in goal-directed behavior. To study involuntary shifts in attention to task-irrelevant deviant stimuli and subsequent reorientation, we used an auditory distraction task and analyzed event-related potential measures (mismatch negativity), P3a and reorienting negativity) of 35 younger, 32 older high-performing, and 32 older low-performing participants. Although both high and low performing elderly individuals showed a delayed reorienting to the primary stimulus feature, relative to young participants, poor performance of the elderly participants in processing of deviant stimuli was associated with strong involuntary attention capture by task-irrelevant features. In contrast, high performance of the elderly group was associated with intensified attentional shifting toward the target features. Thus, it appears that performance deficits in aging are due to higher distractibility in combination with deficits in the orienting-reorienting mechanisms.

Musicians show general enhancement of complex sound encoding and better inhibition of irrelevant auditory change in music: an ERP study

Using electrophysiology, we have examined two questions in relation to musical training - namely, whether it enhances sensory encoding of the human voice and whether it improves the ability to ignore irrelevant auditory change. Participants performed an auditory distraction task, in which they identified each sound as either short (350 ms) or long (550 ms) and ignored a change in timbre of the sounds. Sounds consisted of a male and a female voice saying a neutral sound [a], and of a cello and a French Horn playing an F3 note. In some blocks, musical sounds occurred on 80% of trials, while voice sounds on 20% of trials. In other blocks, the reverse was true. Participants heard naturally recorded sounds in half of experimental blocks and their spectrally-rotated versions in the other half. Regarding voice perception, we found that musicians had a larger N1 event-related potential component not only to vocal sounds but also to their never before heard spectrally-rotated versions. We therefore conclude that musical training is associated with a general improvement in the early neural encoding of complex sounds. Regarding the ability to ignore irrelevant auditory change, musicians' accuracy tended to suffer less from the change in timbre of the sounds, especially when deviants were musical notes. This behavioral finding was accompanied by a marginally larger re-orienting negativity in musicians, suggesting that their advantage may lie in a more efficient disengagement of attention from the distracting auditory dimension.

BDNF Val66Met polymorphism and goal-directed behavior in healthy elderly - evidence from auditory distraction

Aging affects the ability to focus attention on a given task and to ignore distractors. These functions subserve response control processes for which fronto-striatal networks have been shown to play an important role. Within these networks, the brain-derived-neurotrophic-factor (BDNF), which is known to underlie aging effects, plays a pivotal role. We investigated how cognitive subprocesses constituting a cycle of distraction, orientation and refocusing of attention are affected by the functional BDNF Val66Met polymorphism using event-related potentials (ERPs) in 122 healthy elderly. Using an auditory distraction paradigm we found that the Val/Val genotype confers a disadvantage to its carriers. This disadvantage was partly compensated by intensified attentional shifting mechanisms. It could be based on response selection processes being more vulnerable against interference from distractors in this genotype group. Processes reflecting transient sensory memory processes, or the re-orientation of attention were not affected by the BDNF Val66Met polymorphism, suggesting a higher importance of BDNF for mechanisms related to response control, than stimulus processing. The results add on recent literature showing that the Met allele confers some benefit to its carriers. We suggest an account for unifying different results of BDNF Val66Met association studies in executive functions, based on the role of BDNF in fronto-striatal circuits.

The mismatch negativity (MMN)--a unique window to disturbed central auditory processing in ageing and different clinical conditions

In this article, we review clinical research using the mismatch negativity (MMN), a change-detection response of the brain elicited even in the absence of attention or behavioural task. In these studies, the MMN was usually elicited by employing occasional frequency, duration or speech-sound changes in repetitive background stimulation while the patient was reading or watching videos. It was found that in a large number of different neuropsychiatric, neurological and neurodevelopmental disorders, as well as in normal ageing, the MMN amplitude was attenuated and peak latency prolonged. Besides indexing decreased discrimination accuracy, these effects may also reflect, depending on the specific stimulus paradigm used, decreased sensory-memory duration, abnormal perception or attention control or, most importantly, cognitive decline. In fact, MMN deficiency appears to index cognitive decline irrespective of the specific symptomatologies and aetiologies of the different disorders involved.

The cognitive control of distraction by novelty in children aged 7-8 and adults

The study focused on the development of cognitive control of distraction. Novel sounds were interspersed in a sequence of a constant environmental sound, while subjects were engaged in a task not related to novelty. In both children (7-8 years) and adults, unpredictable novel sounds caused prolonged reaction times (RT), the P3a and the Reorienting Negativity (RON) components of the event-related potential, indicating distraction and reorienting of attention. With predictable novels, RT prolongation and RON-amplitude were reduced in both groups, whereas P3a-amplitude reduction was confined to adults. Thus, although children reveal some indication for control of distraction, they do not yet achieve the level of adults. This differential pattern of the development of RT prolongation, P3a, and RON across age groups indicates different maturation of processes involved in the control of distraction and suggests partly independent underlying processes.

Increased cognitive functioning in symptomatic Huntington's disease as revealed by behavioral and event-related potential indices of auditory sensory memory and attention

Cognitive functions are thought to deteriorate globally in late stages of various neurodegenerative disorders. Here we describe that this general assumption is not justified and fails in Huntington's disease (HD). Presymptomatic gene mutation carriers (pHDs) and healthy controls performed worse compared with symptomatic HDs in an auditory signal detection task. During task performance, behavioral data and event-related potentials (ERPs) [i.e., MMN (mismatch negativity), P3a, and RON (reorienting negativity)] were recorded. Not only behavioral performance but also neurophysiological correlates of auditory sensory memory and attentional reorientation indicate enhanced performance occurring primal in late stages of a neurodegenerative disorder. Increased activity of the NMDA-receptor system, an assumed pathogenic mechanism in HD, might facilitate signal propagation at striatal level that enables more efficient task execution through a winner-take-all process. The results challenge the view that late stage neurodegeneration is necessarily related to a global decline in cognitive abilities in HD. In contrast, selectively enhanced cognitive functioning can emerge together with otherwise impaired cognitive functioning.

Regularity Extraction and Application in Dynamic Auditory Stimulus Sequences

Traditional auditory oddball paradigms imply the brain's ability to encode regularities, but are not optimal for investigating the process of regularity establishment. In the present study, a dynamic experimental protocol was developed that simulates a more realistic auditory environment with changing regularities. The dynamic sequences were included in a distraction paradigm in order to study regularity extraction and application. Subjects discriminated the duration of sequentially presented tones. Without relevance to the task, tones repeated or changed in frequency according to a pattern unknown to the subject. When frequency repetitions were broken by a deviating tone, behavioral distraction (prolonged reaction time in the duration discrimination task) was elicited. Moreover, event-related brain potential components indicated deviance detection (mismatch negativity), involuntary attention switches (P3a), and attentional reorientation. These results suggest that regularities were extracted from the dynamic stimulation and were used to predict forthcoming stimuli. The effects were already observed with deviants occurring after as few as two presentations of a standard frequency, that is, violating a just emerging rule. Effects of regularity violation strengthened with the number of standard repetitions. Control stimuli comprising no regularity revealed that the observed effects were due to both improvements in standard processing (benefits of regularity establishment) and deteriorations in deviant processing (costs of regularity violation). Thus, regularities are exploited in two different ways: for an efficient processing of regularity-conforming events as well as for the detection of nonconforming, presumably important events. The present results underline the brain's flexibility in its adaptation to environmental demands.

Cognitive control of involuntary attention and distraction in children and adolescents

The present study focused on the control of involuntary attentional orienting and distraction in children (6-8, 10-12 years) and adolescents (17-18 years). In an auditory distraction paradigm, pitch deviants interspersed in a sequence of standard sounds were presented. In the predictable condition, the type of sound (standard or deviant) was announced by a preceding visual cue. In the unpredictable condition, the cue was not informative with respect to the type of sound. Subjects performed a sound duration discrimination task and were instructed to attend the cues in order to avoid distraction. In the unpredictable condition, regular behavioral and ERP effects of change detection (Mismatch Negativity), attentional orienting (P3a) and distraction (prolonged reaction times) were observed. In the predictable condition, no modulation of Mismatch Negativity amplitude was observed, whereas the amplitude of P3a and reaction time prolongations in deviant trials were reduced in all age groups. Results suggest that even young children are able to voluntarily control involuntary attentional orienting and behavioral distraction. However, significant age effects were observed for the level of behavioral distraction and the selective utilization of the visual cues (reflected by P3b).

Role of Mismatch Negativity and Novelty-P3 in Involuntary Auditory Attention

It has been proposed that the functional role of the mismatch negativity (MMN) generating process is to issue a call for focal attention toward any auditory change violating the preceding acoustic regularity. This paper reviews the evidence supporting such a functional role and outlines a model of how the attentional system controls the flow of bottom-up auditory information with regard to ongoing-task demands to organize goal-oriented behavior. Specifically, the data obtained in auditory-auditory and auditory-visual distraction paradigms demonstrated that the unexpected occurrence of deviant auditory stimuli or novel sounds captures attention involuntarily, as they distract current task performance. These data indicate that such a process of distraction takes place in three successive stages associated, respectively, to MMN, P3a/novelty-P3, and reorienting negativity (RON), and that the latter two are modulated by the demands of the task at hand.