Auditory Stroop Task Research Articles

Performance during attention-demanding walking conditions in older adults

BackgroundConventional balance and gait assessments for fall risk screening are often conducted under unperturbed conditions. However, older adults can allocate their attention to motor tasks (balance or walking) without revealing performance deficiencies, posing a challenge in identifying those with compromised gait and balance. Research questionsDo community-dwelling older adults exhibit greater changes in cognitive and/or walking performance under balance-challenging conditions compared to typical dual-task walking conditions? MethodsTwenty-nine healthy, community-dwelling older adults performed four cognitive tasks (visual and auditory Stroop tasks, Clock task, and Paced Auditory Serial Addition Test) while walking with and without lateral treadmill sways (Perturbed vs. Unperturbed) and during standing. We calculated dual-task costs (DTC) and walking perturbation effects (WPE) as the percentage of change in cognitive and walking performance between dual and single-task conditions and between Perturbed and Unperturbed conditions, respectively. ResultsOlder adults exhibited similar DTC and WPE on cognitive task performance. However, in walking performance, they demonstrated significantly greater WPE than DTC across all gait and stability measures (p < 0.01), including the mean and variability of stride and margins of stability (MOS) measures, the variability of trunk movement and lower-limb joint angles, and the local stability measures. Older adults took shorter but wider steps, exhibited shorter MOSAP but greater MOSML, and experienced increased movement variability and walking instability to a greater extent than during dual-task walking. Overall, changes in variability and stability measures were more pronounced than those in mean gait measures. SignificanceIntroducing destabilizing perturbations to increase the task demands of balance and gait assessments is a more effective method to challenge older adults compared to simply adding a concurrent cognitive task. Fall screening assessments for community-dwelling older adults should incorporate balance-challenging conditions, such as introducing gait perturbations.

Validation of fNIRS measurement of executive demand during walking with and without dual-task in younger and older adults and people with Parkinson’s disease

BackgroundWalking with a concurrent cognitive task (dual-task walking) can pose a challenge to some populations due to aging or neurodegenerative disease. These tasks require cognitive resources involving the prefrontal cortex and can be studied using functional near-infrared spectroscopy (fNIRS). An important step in understanding fNIRS measures during such walking tasks is validating that measures reflect the demands of the tasks and not confounding sources or movement artifacts. AimThis study aimed to investigate the validity of fNIRS measures of prefrontal cortex activity as an indicator of executive demand during usual walking (single-task) and dual-task walking against clinical and objective measures of motor behavior in young adults, older adults, and people with Parkinson’s disease (PD), by evaluating several validation hypotheses. MethodsIn total, 133 participants were recruited from younger adults (18–50 years, n = 42), older adults (≥60 years, n = 49) and people with PD (≥60 years, n = 42). Activity in the prefrontal cortex during walking with and without an auditory Stroop task was measured with fNIRS. A combined hemoglobin measure (correlation-based signal improvement, CBSI) was calculated for use in a region of interest analysis in the dorsolateral prefrontal cortex (dlPFC). Pre-registered hypotheses regarding convergent validity, discriminant validity and known group validity were tested. An exploratory analysis of different hemoglobin measures was also performed. ResultsIncreases in dlPFC activity were found from single- to dual-task walking in the younger adults group and from rest to single-task walking in the older adults and PD groups. In line with hypotheses, a positive relationship was found between between dlPFC activity during dual-task walking and dual-task cost in the younger adults group, as well as a positive relationship to step time variability during single-task walking and a negative relationship to walking speed during single-task walking in the PD group. However, several clinical and gait measures lacked a relationship with dlPFC activity. ConclusionThe fNIRS results point towards the CBSI measure of dlPFC activity being a valid measure of executive demand during both single and dual-task walking. Some relationships between clinical and gait measures and brain activity during walking need further investigation.

Using functional near-infrared spectroscopy to measure prefrontal cortex activity during dual-task walking and navigated walking: A feasibility study.

While functional near-infrared spectroscopy (fNIRS) can provide insight into motor-cognitive deficits during ecologically valid gait conditions, the feasibility of using fNIRS during complex walking remains unknown. We tested the process and scientific feasibility of using an fNIRS device to measure cortical activity during complex walking tasks consisting of straight walking and navigated walking under single and dual-task (DT) conditions. Nineteen healthy people from 18 to 64 years (mean age: 45.7 years) participated in this study which consisted of three complex walking protocols: (i) straight walking, DT walking (walking while performing an auditory Stroop task) and single-task auditory Stroop, (ii) straight and navigated walking, and (iii) navigated walking and navigated DT walking. A rest condition (standing still) was also included in each protocol. Process feasibility outcomes included evaluation of the test procedures and participant experience during and after each protocol. Scientific feasibility outcomes included signal quality measures, and the ability to measure changes in concentration of deoxygenated and oxygenated hemoglobin in the prefrontal cortex. All participants were able to complete the three protocols with most agreeing that the equipment was comfortable (57.9%) and that the testing duration was adequate (73.7%). Most participants did not feel tired (94.7%) with some experiencing pain (42.1%) during the protocols. The signal qualities were high for each protocol. Compared to the rest condition, there was an increase in oxygenated hemoglobin in the prefrontal cortex when performing dual-task walking and navigation. We showed that our experimental setup was feasible for assessing activity in the prefrontal cortex with fNIRS during complex walking. The experimental setup was deemed acceptable and practicable. Signal quality was good during complex walking conditions and findings suggest that the different tasks elicit a differential brain activity, supporting scientific feasibility.

On the Generalizability of the Bodily State Effect on Creativity

ABSTRACT Previous studies found that bodily states have an impact on divergent thinking, but it remains to be seen how generalizable this effect could be, how exactly it depends on cognitive control, and whether similar effects can be found on convergent thinking. To address these questions, we examined the bodily state effect on divergent thinking, convergent thinking, and cognitive control in two experiments. In Experiment 1, participants performed the Alternate Uses Task, the Remote Associates Task, and an auditory Stroop task under one of the three bodily states: sitting, standing, or roaming. In Experiment 2, participants completed the three tasks while standing and while roaming. Results showed that bodily state had no significant effect on divergent thinking and the Stroop effect, while roaming shorten the reaction times (Experiment 1) and increased accuracy (Experiment 2) comparing with sitting or standing in the convergent thinking task. Bayesian analysis provided strong or moderately strong evidence for the null hypothesis for these effects. Taken together, the present experiments showed no stable bodily state effect on divergent thinking or convergent thinking and Stroop effect. Possible explanations for the discrepancy between the current results and those reported in previous studies were discussed.

Benefits of implanted peroneal functional electrical stimulation for continual gait adaptations in people with 'drop foot' due to chronic stroke.

Benefits of peroneal functional electrical stimulation in people with post-stroke drop foot may particularly emerge in environments that require continual gait adaptation. Such adaption is known to increase the attentional demands of gait. Is performance of a target stepping task more accurate and less attention demanding with electrical stimulation ON compared to OFF in people with post-stroke drop foot? Thirteen people with an implanted electrical stimulation system participated in this observational study. Participants performed a walking task with irregularly spaced targets on a self-paced treadmill, both as a single task and combined with an auditory Stroop task. Participants performed each task with electrical stimulation ON and OFF. In the OFF condition participants were allowed to use their own ankle-foot orthosis. The effects of Device (ON, OFF) and interaction of Device*Task (single, dual) on stepping performance in mediolateral and anteroposterior direction were tested based on the total error of foot placement relative to the targets, using repeated measurements ANOVA. Differences between electrical stimulation ON and OFF on auditory Stroop task accuracy were assessed using a non-parametric Wilcoxon signed-rank test. Non-parametric correlations were calculated to associate changes in stepping performance with paretic leg motor function (Fugl-Meyer Assessment - leg score). Data of 12 participants were used for analysis. Mediolateral total error was smaller with peroneal functional electrical stimulation ON compared to OFF (Δ=1.0cm, p=0.011). In the anteroposterior direction, no significant effects of Device were found. There were no significant interaction effects of Device*Task in either direction. Changes in total error (ON vs OFF) were not significantly associated with leg motor function. Stroop task accuracy was not statistically different between ON and OFF. Implanted electrical stimulation may have benefits with regard to mediolateral accuracy of a continual target stepping task, although the effect size is relatively small. This benefit seems to be independent of the performance of a concurrent attention-demanding task and may reflect better gait stability in the mediolateral direction, which is known to be a problem in people with stroke.

Reliability of Center of Pressure measures of Postural Stability in Anterior Cruciate Ligament Reconstructed Athletes: Effect of Vibration and Cognitive Load.

To evaluate intra and intersession reliability of the Center of Pressure (COP) parameters in Anterior Cruciate Ligament Reconstructed (ACLR) athletes with and without ankle vibration using a dual-task paradigm. Postural sway of 14 ACLR individuals was assessed during a single-leg stance on a force platform. COP parameters were assessed with manipulating sensory inputs via vision and ankle vibration under single and dual-task conditions. The outcome variables included COP displacement in medial-lateral (ML) and anterior-posterior (AP) range, mean velocity (mV), and area. During dual-task conditions, the auditory Stroop Task was applied. Intraclass correlation coefficient (ICC) values and standard error of measurement (SEM) were assessed for relative and absolute reliability. The COP measures had moderate to very high intrasession reliability (ICC range: 0.51-0.93) for conditions with vibration and cognitive task, with the highest ICCs for mV and the lowest for area, regardless of eyes being open or closed. The intersession reliability was moderate to high for mV (ICC range: 0.60-0.82) and little to very high (ICC range: 0.21-0.97) for the range of ML and AP, as well as an area in conditions with vibration and cognitive task. The mV is the most reliable COP parameter for assessing postural control under ankle vibration and dual-task conditions for both operated and non-operated sides. During closed-eye conditions, the application of vibration affected the intersession reliability with decreased ICCs on the operated side and increased ICCs on the non-operated side.

Assessing the impact of dual-task reactive step practice in people with Parkinson's disease: A feasibility study.

Reactive stepping is impaired in people with Parkinson's Disease (PD) but can be improved with training. However, it is unclear if reactive steps can be improved when performing a concurrent cognitive task, a common and fall-relevant circumstance. We assessed the feasibility and preliminary effectiveness of dual-task reactive step training. Specifically, we measured whether stepping and cognitive reaction time are improved after one day of dual-task reactive step practice and if improvements are retained 24h later. Sixteen people with PD and 13 age-matched healthy controls (HC) underwent repeated from-stance support surface perturbations that elicited a reactive step while performing an auditory Stroop task. Participants returned the following day to reassess dual-task reactive stepping performance. Cognitive, neuromuscular, and stepping outcomes were calculated. Increased step lengths were observed for both groups after practice (p<0.001). Cognitive reaction times also improved through practice; however, this was more pronounced in the HC group (group by time interaction- p<0.001). No changes were observed for step latency, margin of stability, or EMG onset through practice. Step length and cognitive reaction time improvements were retained 24h after practice in both groups (step length: p<0.001; cognitive reaction time: p=0.05). This study provides preliminary evidence for the effectiveness of dual-task reactive step training to improve step length in people with PD. The improvements in step length without compromising cognitive reaction times suggest that participants improved reactive stepping without a robust attention shift toward the postural task. Future research is necessary to determine optimal training protocols and determine if such training protocols impact falls in PD patients.

Motor adaptation to cognitive challenges and walking perturbations in healthy young adults

BackgroundCognitive-walking interference is manifested when simultaneously performing a cognitive task while walking. However, majority of the dual-task walking paradigms incorporated relatively short testing trials and were focused on posing a cognitive challenge by adding a secondary cognitive task but not introducing walking perturbations. Research questionHow do healthy young adults adapt to concurrent cognitive challenges and walking perturbations in terms of task prioritization and adaptation strategies to control walking stability? MethodsEighteen healthy young participants walked with and without (1) continuous treadmill platform sways (Perturbed and Unperturbed walking), and (2) performing one of the cognitive tasks: visual and auditory Stroop tasks, Clock task, Paced Auditory Serial Addition Test (PASAT), and walk only. Primary outcome measures included cognitive task performance, mediolateral dynamic margins of stability (MOSML), M-L local dynamic stability, stride time variability and the dual-task interference (DTI) on these measures. ResultsGait adjustments made during Perturbed walking did not improve walking stability but instead, showing more local instability and greater gait variability (all p < 0.001) than Unperturbed walking. Participants increased average MOSML during Clock and PASAT compared to Walk Only for both Perturbed and Unperturbed walking (THSD, p < 0.05). Participants had significantly less DTI on stride time variability during Unperturbed walking than during Perturbed walking (p < 0.001). Participants also had significantly greater DTI on PASAT performance during Perturbed than during Unperturbed walking (THSD, p < 0.05) SignificanceParticipants prioritized the walking task under a more challenging walking condition although the adjustments made during Perturbed walking were not sufficient to maintain a similar level of walking stability as Unperturbed walking. Adjustments to the cognitive-walking challenges were differed by the type of cognitive tasks. The current findings suggest that cognitive tasks involving both working memory and information processing or visuospatial recognition or attention have greater impact on gait especially during the perturbed walking condition.

Association between functional physical capacity and cognitive performance under destabilizing walking conditions in older adults.

Cognitive decline increases the risk of falls in older adults. Understanding the association between cognitive function, functional physical capacity, and falls may help identify targets for fall screening and intervention. This study examined (1) cognitive and functional physical capacity in community-dwelling older adults with and without a history of falls or the presence of brain-derived neurotrophic factor (BDNF) gene Val66Met polymorphism (Val/Met), and (2) the association between their cognitive and functional physical capacity, focusing on the cognitive performance during dual-task, challenging walking conditions. Twenty-nine healthy, community-dwelling older adults attended two testing sessions for (1) functional assessments of physical capacity and global cognitive status, and (2) performing four cognitive tasks (visual and auditory Stroop tasks, Clock task, and Paced Auditory Serial Addition Test) during standing and while walking on the treadmill with and without medio-lateral treadmill platform sways. Participants with a fall history had reduced functional reach distance whereas individuals with Val/Met had reduced functional gait assessment (FGA) score compared to their controls. In addition, participants with a fall history or Val/Met showed reduced Clock task performance under dual-task conditions. Among all cognitive tasks, visual-Stroop performance, especially during the perturbed walking conditions, was significantly correlated with more physical capacity items. The performance of the other three cognitive tasks provided complementary information on those items not correlated with visual-Stroop performance. Clock task performance can distinguish fallers from non-fallers as well as older adults with and without the BDNF gene polymorphism. Administering different types of cognitive tasks and under more challenging walking conditions can better reveal the association between cognitive and functional physical capacity in older adults. Fall screening and prevention intervention should integrate cognitive tasks into the functional physical capacity assessment and training regime, and progress to a more challenging condition such as introducing gait or balance perturbations during the assessment or training.

Neural Dynamics of Inhibitory Control in Musicians with Absolute Pitch: Theta Synchrony as an Oscillatory Signature of Information Conflict.

Absolute pitch (AP) is the ability to identify an auditory pitch without prior context. Current theories posit AP involves automatic retrieval of referents. We tested interference in well-matched AP musicians, non-AP musicians, and nonmusicians with three auditory Stroop tasks. Stimuli were one of two sung pitches with congruent or incongruent verbal cues. The tasks used different lexicons: binary concrete adjectives (i.e., words: Low/High), syllables with no obvious semantic properties (i.e., solmization: Do/So), and abstract semiotic labels (i.e., orthographic: C/G). Participants were instructed to respond to pitch regardless of verbal information during electroencephalographic recording. Incongruent stimuli of words and solmization tasks increased errors and slowed response times (RTs), which was reversed in nonmusicians for the orthographic task. AP musicians made virtually no errors, but their RTs slowed for incongruent stimuli. Frontal theta (4–7 Hz) event-related synchrony was significantly enhanced during incongruence between 350 and 550 ms poststimulus onset in AP, regardless of lexicon or behavior. This effect was found in non-AP musicians and nonmusicians for word task, while orthographic task showed a reverse theta congruency effect. Findings suggest theta synchrony indexes conflict detection in AP. High beta (21–29 Hz) desynchrony indexes response conflict detection in non-AP musicians. Alpha (8–12 Hz) synchrony may reflect top-down attention.

Cognitive and motor task performance under single- and dual-task conditions: effects of consecutive versus concurrent practice

The concurrent execution of two or more tasks simultaneously results in performance decrements in one or both conducted tasks. The practice of dual-task (DT) situations has been shown to decrease performance decrements. The purpose of this study was to investigate the effects of consecutive versus concurrent practice on cognitive and motor task performance under single-task (ST) and DT conditions. Forty-five young adults (21 females, 24 males) were randomly assigned to either a consecutive practice (INT consecutive) group, a concurrent practice (INT concurrent) group or a control (CON) group (i.e., no practice). Both INT groups performed 2 days of acquisition, i.e., practicing a cognitive and a motor task either consecutively or concurrently. The cognitive task required participants to perform an auditory stroop task and the number of correct responses was used as outcome measure. In the motor task, participants were asked to stand on a stabilometer and to keep the platform as close to horizontal as possible. The time in balance was calculated for further analysis. Pre- and post-practice testing included performance assessment under ST (i.e., cognitive task only, motor task only) and DT (i.e., cognitive and motor task simultaneously) test conditions. Pre-practice testing revealed no significant group differences under ST and DT test conditions neither for the cognitive nor the motor task measure. During acquisition, both INT groups improved their cognitive and motor task performance. The post-practice testing showed significantly better cognitive and motor task values under ST and DT test conditions for the two INT groups compared to the CON group. Further comparisons between the two INT groups revealed better motor but not cognitive task values in favor of the INT consecutive practice group (ST: p = 0.022; DT: p = 0.002). We conclude that consecutive and concurrent practice resulted in better cognitive (ST condition) and motor (ST and DT test conditions) task performance than no practice. In addition, consecutive practice resulted in superior motor task performance (ST and DT test conditions) compared to concurrent practice and is, therefore, recommended when executing DT practice schedules.

Exploring the cognitive demands required for young adults to adjust online obstacle avoidance strategies.

Humans integrate visual information about their surrounding environment to properly adapt their locomotion to step over or around obstacles in their path. We know that cognition aids in the execution of locomotion and in complex maneuvers such as obstacle avoidance. However, the role of the cognitive system in performing online adjustments to an obstacle avoidance strategy during locomotion has not yet been elucidated. Nineteen young adults instrumented with kinematic markers were asked to step over or circumvent an obstacle to the left or right. In half of these trials, participants were required to adjust this strategy when cued by LED lights two steps prior to obstacle crossing. In 75% of trials, a cognitive task was simultaneously presented (incongruent or congruent auditory Stroop cue, or neutral cue). Center of mass position and velocity was estimated and gait metrics (eg. step length) were calculated to quantify how individuals performed this last-minute direction change and determine how these responses changed when simultaneously performing a cognitive task. Results showed statistically shorter crossing steps, where the trailing limb was placed further from the leading edge and the lead limb was placed closer to the trailing edge when responding to the auditory Stroop task. Performing these avoidance strategy changes also decreased cognitive task performance. Our findings suggest that visually integrating a new stepping pattern to cross an obstacle is a complex locomotor maneuver, and requires the aid of the cognitive system to be performed effectively in a young adult population.

Anything He Can Do, She Can Do Better: Children’s Attitudes About Gender and Occupations

Children’s career aspirations are affected by cultural stereotypes about gender. We investigated rudimentary implicit associations and explicit gender attitudes about occupations with a diverse sample of fifty-eight (29 girls, 29 boys) 10-year-old children. We tested implicit gender associations using an adapted auditory Stroop task and tested explicit gender attitudes using the Gender-Stereotyped Attitude Scale for Children (GASC). We also modified a version of the GASC to assess children’s attitudes about a female and a male firefighter-paramedic seen in a brief video. Children also judged the firefighter-paramedics’ job skills. Children did not display implicit associations between occupations and one’s gender based on differences in the response times between the congruent and incongruent test trials that paired male and female voices with occupations, t(1762) = 0.65, p = .52, d = 0.03. Auditory voice stimuli might have confounded the tested associations between gender and occupations. The GASC findings highlighted gender stereotype flexibility about men and women. Girls were more flexible than boys on the job component of the GASC, t(56) = −2.12, p = .039, d = 0.55. The level of children’s gender stereotype flexibility varied by occupation. Children exhibited the most flexibility for who should be a doctor and the least flexibility for who should be a ballet dancer/teacher. Lastly, we assessed attitudes toward the specific woman featured in the video; children overwhelmingly saw her as a potentially good fire chief (vs. the man featured in the video; 91% selected Kate or both for who would be a better fire chief).

Does conflict resolution rely on working memory?

Theoretical considerations and results from individual differences studies suggest that working memory and conflict resolution are interrelated functions. Yet, there is little direct evidence suggesting that they actually share common cognitive resources. To study how overcoming conflict influences the maintenance of working memory representations and vice versa, we conducted 4 experiments using a dual-task paradigm in which both working memory load and level of conflict were independently manipulated. Participants performed an auditory Stroop task ("high" or "low" spoken in high/low pitch), which was presented during the retention period of a visual change detection task (Experiments 1-4) or simultaneously with the working memory encoding phase (Experiment 2-4). Across the 4 experiments, we found no consistent interaction between level of conflict and working memory load on working memory performance, although there was evidence in 2 of the 4 experiments for a small effect on auditory Stroop accuracy (but not on response times). These findings present at best weak evidence for the hypothesis that the maintenance of task goals in working memory is critical for successful conflict resolution. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

Loudness and Intelligibility of Irrelevant Background Speech Differentially Hinder Children's Short Story Reading

Reading skills are usually assessed in silent conditions, but children often experience noisy educational settings. Effects of auditory distraction on children's reading skills remain relatively unexplored. The present study investigates the influence of two features of background speech—intelligibility and loudness—on children's reading speed and comprehension. Sixty‐three 8‐to‐10‐year‐old elementary school children performed a reading task in the context of single‐talker background speech. Background speech was either intelligible or unintelligible and presented at low (45–50 dB SPL) or moderate (65–72 dB SPL) sound intensity (here termed “loudness”). Results showed a differential effect of intelligibility and loudness, respectively affecting children's comprehension and reading speed. In addition, the intelligibility effect was larger in children with lower interference control, as assessed with an auditory Stroop task. Our findings provide evidence for the influence of different properties of background speech on children's text reading with implications for reading in everyday classroom environments.Lay SummaryChildren often read in noisy environments, but we know little about how background chatter might affect their reading. Here, we found that 8–10‐year‐old children read stories more slowly with louder background speech. The children also understood less about a story if the background voice was speaking in their own language—especially those who, in a different task, were less able to ignore irrelevant but attention‐grabbing information. This suggests background speech differentially affects beginning readers.

Reproducibility in Cognitive Hearing Research: Theoretical Considerations and Their Practical Application in Multi-Lab Studies.

In this article, we consider the issue of reproducibility within the field of cognitive hearing science. First, we examine how retest reliability can provide useful information for the generality of results and intervention effectiveness. Second, we provide an overview of retest reliability coefficients within three areas of cognitive hearing science (cognition, speech perception, and self-reported measures of communication) and show how the reporting of these coefficients differs between fields. We argue that practices surrounding the provision of retest coefficients are currently most rigorous in clinical assessment and that basic science research would benefit from adopting similar standards. Finally, based on a distinction between direct replications (which aim to keep materials as close to the original study as possible) and conceptual replications (which test the same purported mechanism using different materials), we discuss new initiatives which address the need for both. Using the example of the auditory Stroop task, we provide practical illustrations of how these theoretical issues can be addressed within the context of a multi-lab replication study. By illustrating how theoretical concepts can be put into practice in empirical research, we hope to encourage others to set up and participate in a wide variety of reproducibility-related studies.

The Influence of Hearing Loss on Cognitive Control in an Auditory Conflict Task: Behavioral and Pupillometry Findings.

Purpose The pupil dilation response is sensitive not only to auditory task demand but also to cognitive conflict. Conflict is induced by incompatible trials in auditory Stroop tasks in which participants have to identify the presentation location (left or right ear) of the words "left" or "right." Previous studies demonstrated that the compatibility effect is reduced if the trial is preceded by another incompatible trial (conflict adaptation). Here, we investigated the influence of hearing status on cognitive conflict and conflict adaptation in an auditory Stroop task. Method Two age-matched groups consisting of 32 normal-hearing participants (M age = 52 years, age range: 25-67 years) and 28 participants with hearing impairment (M age = 52 years, age range: 23-64 years) performed an auditory Stroop task. We assessed the effects of hearing status and stimulus compatibility on reaction times (RTs) and pupil dilation responses. We furthermore analyzed the Pearson correlation coefficients between age, degree of hearing loss, and the compatibility effects on the RT and pupil response data across all participants. Results As expected, the RTs were longer and pupil dilation was larger for incompatible relative to compatible trials. Furthermore, these effects were reduced for trials following incompatible (as compared to compatible) trials (conflict adaptation). No general effect of hearing status was observed, but the correlations suggested that higher age and a larger degree of hearing loss were associated with more interference of current incompatibility on RTs. Conclusions Conflict processing and adaptation effects were observed on the RTs and pupil dilation responses in an auditory Stroop task. No general effects of hearing status were observed, but the correlations suggested that higher age and a greater degree of hearing loss were related to reduced conflict processing ability. The current study underlines the relevance of taking into account cognitive control and conflict adaptation processes.

Serial 7’S Do Not Discriminate Between Sports-related Concussion And Controls: Alternative Dual-task Paradigms

Dual-task (DT) tandem gait has been used as a viable, functional task of postural stability and cognitive changes following a sports-related concussion (SRC). Additionally, completing tasks that test cognitive abilities during DT, such as serial 7’s, is thought to capture cognitive changes. However, current methods of collecting DT information may not have sensitive psychometric properties. PURPOSE: The purpose of this study was to examine differences in time and errors in DT tandem gait testing between NCAA Division I athletes with and without SRC. METHODS: 13 Division I athletes with sports-related concussion (SRC: 6 males and 7 females, age=20±1) and 13 nearly-matched controls (CON: age=19±1) completed three trials of DT tandem gait using the Tekscan Strideway (100Hz, Boston, MA). All SRC participants had a medically-verified SRC and were assessed within 24-48 hours post-injury. All CON assessments were collected during pre-season. In the DT condition, all participants completed serial 7’s subtraction with random numbers between 50-100. Data collected for tandem gait trials included time to complete the walking task and number of errors emitted. RESULTS: Paired t-tests were used to assess the differences across the average time and errors across trials. Results indicate that the SRC group (M time=23.7±7.5s) took significantly longer to complete DT compared to the CON group (M time=17.2±5.1s, p=0.03, d=1.0). Total amount of errors emitted during the DT were not significantly different (SRC: M errors=1.3±1.6, CON: M errors =0.7±0.6, p=0.18, d=0.49). CONCLUSIONS: Only time in DT trials appears to be a viable method of discriminating between participants who experienced an SRC compared to those without SRC. This indicates that errors emitted during a serial 7’s task may not provide meaningful information regarding cognitive changes following SRC. Extant literature indicates that serial 7’s may be a favored task among researchers, however, alternative tasks may provide a more sensitive measure of cognitive changes. Future research should examine the use of alternative tasks, such as an auditory Stroop task, which may provide more clinically meaningful data.

Reward expectation modulates multiple stages of auditory conflict control

Although mounting evidence has shown that reward can improve conflict control in the visual domain, little is known about whether and how reward affects conflict processing in the auditory domain. In the present study, we adopted an auditory Stroop task in which the meaning of a sound word (‘male’ or ‘female’) could be either congruent or incongruent with the gender of the voice (male or female speaker), and the participants were asked to discriminate the gender of the voice (the phonetic task) or the meaning of the word (the semantic task). Importantly, an auditory cue signalling a potential reward or no-reward for the current trial was presented prior to the sound word. In both tasks, relative to the congruent sound word, response to the incongruent sound word was delayed, i.e., an auditory Stroop effect. However, this auditory Stroop effect was reduced following a reward cue relative to a no-reward cue. Event-related potentials (ERPs) showed a stronger contingent negativity variation (CNV, 1000–1500 ms) for the reward cue than for the no-reward cue. The conflict negativity Ninc (300–400 ms) was more negative-going for the incongruent word than for the congruent word, but this effect was significantly reduced in the reward condition. However, the late positive complex (LPC) showed at most a weak reward modulation. These findings suggest that reward expectation improves auditory conflict control by modulating different stages of conflict processing: promoting better attentional preparation for the upcoming target (CNV), and facilitating conflict detection (Ninc) on the presentation of the target.

Validation of the Auditory Stroop Task to increase cognitive load in walking tasks in healthy elderly and persons with Parkinson’s disease

BackgroundThe development of treatments for freezing of gait (FOG) in Parkinson’s disease (PD) requires experimental study set-ups in which FOG is likely to occur, and is amenable to therapeutic interventions. We explore whether the ‘Auditory Stroop Task’ (AST) can be used to increase cognitive load (and thereby elicit FOG), simultaneously with visual cues (as a therapeutic intervention for FOG). We additionally examined how these two contrasting effects might interact in affecting gait and FOG parameters.ObjectivesWe investigated whether: (1) the ‘Auditory Stroop Task’ (AST) influences gait in healthy elderly and persons with PD who experience FOG, and increases the frequency of FOG events among PD patients; (2) the AST and visual cues interact; and (3) different versions of the AST exert different cognitive loads.MethodsIn ‘Experiment 1’, 19 healthy elderly subjects performed a walking task while performing a high and low load version of the AST. Walking with a random numbers task, and walking without cognitive load served as control conditions. In ‘Experiment 2’, 20 PD patients with FOG and 18 healthy controls performed a walking task with the AST, and no additional cognitive load as control condition. Both experiments were performed with and without visual cues. Velocity, cadence, stride length, and stride time were measured in all subjects. FOG severity was measured in patients.ResultsCompared to the control conditions, the AST negatively affected all gait parameters in both patients and controls. The AST did not increase the occurrence of FOG in patients. Visual cues reduced the decline in stride length induced by cognitive load in both groups. Both versions of the AST exerted similar effects on gait parameters in controls.ConclusionsThe AST is well-suited to simulate the effects of cognitive load on gait parameters, but not FOG severity, in gait experiments in persons with PD and FOG.