Auditory Conditioning Research Articles

Vocal fold nodules: A disorder of phonation organs or auditory feedback?

Increasing evidence supports that auditory feedback of one's own voice closely relates to real-time adjustments of vocal control. Previous studies highlighted that the low-frequency modulations of below 3Hz (LFM) embedded in vocal fundamental frequency (F0) showed a reflex-like response to altered auditory inputs. However, the auditory feedback control of different vocal disorders remains unclear. A cross-sectional, case-controlled study. A tertiary medical centre. Sustained vocalisations of vowel/a/ from adult healthy controls and patients with vocal fold nodules, vocal fold polyps and vocal fold cysts, respectively. The vocalisations were made at a comfortable pitch and at the intensity of 70~80 dBC under the following four auditory conditions: natural hearing, 90-dBC speech noise, 10-dBC enhanced feedback of self-produced voice and both the noise and voice feedback. Power spectral analysis of F0 contour of sustained vowel. Patients with vocal fold nodules presented with different audio-vocal feedback behaviour and audio-vocal response to speech noise from the other two vocal pathologies of vocal fold polyp and vocal fold cyst as well as the healthy controls (P<.001, one-way ANOVA). The vocal fold nodules may be not only a vocal fold disease but also a disease caused by abnormal audio-vocal feedback. Moreover, the distinct audio-vocal feedback of vocal fold nodules could be revealed by power spectral analysis of vocal fundamental frequencies. Although further investigations are necessary, adjustments of audio-vocal feedback behaviour may provide a new insight and benefit to the treatment of vocal fold nodules in the future.

Audiovisual Speech Enhancement via Cross-Modal Suppression of Auditory Association Cortex by Visual Speech

Abstract INTRODUCTION Speech is multisensory. The addition of visual speech to auditory speech greatly improves comprehension, especially under noisy auditory conditions. However, the neural mechanism for this visual enhancement of auditory speech is poorly understood. We used electrocorticography (ECoG) to study how auditory, visual, and audiovisual speech is processed in the posterior superior temporal gyrus (pSTG), an area of auditory association cortex involved in audiovisual speech integration. We hypothesized that early visual mouth movements modulate audiovisual speech integration through a mechanism of cross-modal suppression, suggesting that the pSTG response to early mouth movements should correlate with comprehension benefits gained by the addition of visual speech to auditory speech. METHODS Words were presented under auditory-only (AUD), visual-only (VIS), and audiovisual (AV) conditions to epilepsy patients (n = 8) implanted with intracranial electrodes for phase-2 monitoring. We measured high-frequency broadband activity (75-150 Hz), a marker for local neuronal firing, in 28 electrodes over the pSTG. RESULTS The early neural response to visual-only words was compared to the reduction in neural response seen from AUD to AV words, a reduction correlated with an improvement in speech comprehension that occurs with the addition of visual to auditory speech. In words that showed a comprehension benefit with the addition of visual speech, there was a strong early response to visual speech and a correlation between early visual response and the AUD-AV difference (r = 0.64, P = 104). In words where visual speech did not provide any comprehension benefit, there was a weak early visual response and no correlation (r = 0.18, P = .35). CONCLUSION Words with a visual speech comprehension benefit also elicit a strong neural response to early visual speech in pSTG, while words with no comprehension benefit do not cause a strong early response. This suggests that cross-modal suppression of auditory association cortex (pSTG) by early visual plays an important role in audiovisual speech perception.

Speech-ABR in contralateral noise: A potential tool to evaluate rostral part of the auditory efferent system

In parallel with the auditory afferent system, the auditory efferent system is active in all parts of the auditory pathways from auditory cortex to the cochlea. The auditory efferent system has two main segments: the rostral and the caudal parts. The rostral part, which starts from the cortical centers to thalamic nuclei and continues into collicular pathways in rostral brainstem, which sends its neural fibers to the main collicular nuclei especially inferior colliculus. The caudal part includes the olivocochlear bundle, which originates from the superior olivary complex and terminates on the cochlear hair cells. Most studies about the auditory efferent system have focused only on the caudal part using otoacoustic emission suppression test. Speech-evoked auditory brainstem response (S-ABR) as an electrophysiologic test that uses speech stimuli to simulate real-life auditory conditions, reflects the performance of rostral brainstem centers, so structurally seems to be an appropriate candidate to examine the rostral part of the auditory efferent system. Our hypothesis is that S-ABR in noisy condition, a typical condition for stimulating the auditory efferent system, has the potential to be used as an objective noninvasive electrophysiologic test for studying the rostral auditory efferent system in diagnosis and treatment/rehabilitation follow-ups. In addition, S-ABR can potentially reflect higher-order auditory functions and the effects of their dysfunctions on the lower brainstem. This characteristic makes S-ABR even more suitable tool for evaluation of the efferent system. To evaluate our hypothesis, Eighteen normal hearing subjects in the age range of 18–25 were tested in a pilot study for S-ABR in quiet mode and three signal to noise ratios of +10,0 and −10 for both ears. Then we checked the correlation between the results of S-ABR in different conditions and scores of auditory behavioral tests that auditory efferent system is involved in them: Consonant-Vowel perception in noise, dichotic Consonant-Vowel-Consonant and sound lateralization in noise. The results of our pilot study showed a significant correlation between S-ABR changes in noise with the scores of the behavioral tests in noisy or dichotic situations. Findings of the current study suggest that S-ABR with specific contralateral noise can be an appropriate option for evaluating the performance of rostral part of the auditory efferent system and may be suitable for top-down auditory training follow-ups, although the generalization of these results needs further studies in different groups with different auditory processing abnormalities or skills.

The effects of voice content on stress reactivity: A simulation paradigm of auditory verbal hallucinations

ObjectivesPsychosis is associated with increased subjective and altered endocrine and autonomic nervous system stress-reactivity. Psychosis patients often experience auditory verbal hallucinations, with negative voice content being particularly associated with distress. The present study developed a voice-simulation paradigm and investigated the effect of simulated voices with neutral and negative content on psychophysiological stress-reactivity, and the effect of mindful voice-appraisals on stress-reactivity. MethodEighty-four healthy participants completed the Montreal Imaging Stress Task with simultaneous presentation of one of three randomly allocated auditory stimuli conditions: negative voices, neutral voices or non-voice ambient sounds. Subjective stress-levels and mindful voice-appraisals were assessed using questionnaire measures, and cortisol and α-amylase levels were measured using saliva samples. ResultsANOVA revealed a significant effect of condition on subjective stress-levels (p = .002), but not cortisol (p = .63) or α-amylase (p = .73). Post-hoc analyses showed that negative voices increased subjective stress-levels relative to neutral voices (p = .002) and ambient sounds (p = .01), which did not differ from each other (p = .41). Mindful voice-appraisals were associated with less distress across conditions (p = .003), although negative voices were also associated with less mindful appraisals (p < .001). ConclusionsNegative voice content, rather than voices or auditory stimuli per se, is linked to greater subjective but not physiological stress-reactivity. Mindful appraisals may partially moderate this effect. These findings highlight the importance of voice content for the impact of voice-hearing, and highlight the potential value of mindfulness training to treat voice distress in psychosis.

Continuous 12 min walking to music, metronomes and in silence: Auditory-motor coupling and its effects on perceived fatigue, motivation and gait in persons with multiple sclerosis

BackgroundIn Persons with Multiple Sclerosis (PwMS), coupling walking to beats/pulses in short bursts is reported to be beneficial for cadence and perceived fatigue. However it is yet to be investigated if coupling and its effects can be sustained for longer durations, required for task-oriented training strategy in PwMS. AimsTo investigate if PwMS compared to healthy controls (HC) sustain synchronization for 12 min when walking to music and metronome, and its effects on perceived physical and cognitive fatigue, motivation and gait compared to walking in silence. MethodsParticipants walked for 12 min in three conditions (music, metronome and silence). The tempo of the auditory conditions was individualized. Auditory-motor coupling and spatio-temporal gait parameters were measured during walking. The visual analogue scale was used for perceived fatigue, and the Likert scale for motivation. Results27 PwMS and 28 HC participated. All participants synchronized to both stimuli, yet PwMS synchronized better to music. Overall, participants had lower cadence, speed and stride length when over time all conditions, with an exception of HC, with increasing cadence during the music condition. PwMS perceived less cognitive fatigue, no difference in perceived physical fatigue and a higher motivation walking to music compared to metronomes and silence. Conclusion12 min of uninterrupted walking was possible in PwMS in all conditions, while better synchronization, low perception of cognitive fatigue and high motivation occurred with music compared to other conditions. Coupling walking to music could offer novel paradigms for motor task-oriented training in PwMS.

Comparing statistical learning across perceptual modalities in infancy: An investigation of underlying learning mechanism(s).

Statistical learning (SL), sensitivity to probabilistic regularities in sensory input, has been widely implicated in cognitive and perceptual development. Little is known, however, about the underlying mechanisms of SL and whether they undergo developmental change. One way to approach these questions is to compare SL across perceptual modalities. While a decade of research has compared auditory and visual SL in adults, we present the first direct comparison of visual and auditory SL in infants (8-10months). Learning was evidenced in both perceptual modalities but with opposite directions of preference: Infants in the auditory condition displayed a novelty preference, while infants in the visual condition showed a familiarity preference. Interpreting these results within the Hunter and Ames model (1988), where familiarity preferences reflect a weaker stage of encoding than novelty preferences, we conclude that there is weaker learning in the visual modality than the auditory modality for this age. In addition, we found evidence of different developmental trajectories across modalities: Auditory SL increased while visual SL did not change for this age range. The results suggest that SL is not an abstract, amodal ability; for the types of stimuli and statistics tested, we find that auditory SL precedes the development of visual SL and is consistent with recent work comparing SL across modalities in older children.

Auditory and Semantic Cues Facilitate Decoding of Visual Object Category in MEG.

Sounds (e.g., barking) help us to visually identify objects (e.g., a dog) that are distant or ambiguous. While neuroimaging studies have revealed neuroanatomical sites of audiovisual interactions, little is known about the time course by which sounds facilitate visual object processing. Here we used magnetoencephalography to reveal the time course of the facilitatory influence of natural sounds (e.g., barking) on visual object processing and compared this to the facilitatory influence of spoken words (e.g., "dog"). Participants viewed images of blurred objects preceded by a task-irrelevant natural sound, a spoken word, or uninformative noise. A classifier was trained to discriminate multivariate sensor patterns evoked by animate and inanimate intact objects with no sounds, presented in a separate experiment, and tested on sensor patterns evoked by the blurred objects in the 3 auditory conditions. Results revealed that both sounds and words, relative to uninformative noise, significantly facilitated visual object category decoding between 300-500ms after visual onset. We found no evidence for earlier facilitation by sounds than by words. These findings provide evidence for a semantic route of facilitation by both natural sounds and spoken words, whereby the auditory input first activates semantic object representations, which then modulate the visual processing of objects.

Tasked-Based Functional Brain Connectivity in Multisensory Control of Wrist Movement After Stroke.

In this study we documented brain connectivity associated with multisensory integration during wrist control in healthy young adults, aged matched controls and stroke survivors. A novel functional MRI task paradigm involving wrist movement was developed to gain insight into the effects of multimodal sensory feedback on brain functional networks in stroke participants. This paradigm consisted of an intermittent position search task using the wrist during fMRI signal acquisition with visual and auditory feedback of proximity to a target position. We enrolled 12 young adults, 10 participants with chronic post-stroke hemiparesis, and nine age-matched controls. Activation maps were obtained, and functional connectivity networks were calculated using an independent component analysis (ICA) approach. Task-based networks were identified using activation maps, and nodes were obtained from the ICA components. These nodes were subsequently used for connectivity analyses. Stroke participants demonstrated significantly greater contralesional activation than controls during the visual feedback condition and less ipsilesional activity than controls during the auditory feedback condition. The sensorimotor component obtained from the ICA differed between rest and task for control and stroke participants: task-related lateralization to the contralateral cortex was observed in controls, but not in stroke participants. Connectivity analyses between the lesioned sensorimotor cortex and the contralesional cerebellum demonstrated decreased functional connectivity in stroke participants (p < 0.005), which was positively correlated the Box and Blocks arm function test (r2 = 0.59). These results suggest that task-based functional connectivity provides detail on changes in brain networks in stroke survivors. The data also highlight the importance of cerebellar connections for recovery of arm function after stroke.

Effects of Instructor Gender, Visual, and Auditory Melodic Recorded Instruction on Sequential Working Memory Recall in Individuals with and without Autism Spectrum Disorder

There is a lack of empirical inquiry concerning the effect of the therapist’s gender and aspects of visual and auditory melodic instruction on working memory recall in individuals with Autism Spectrum Disorder (ASD). The purpose of this study was to examine the effects of instructor gender and visual and auditory melodic instruction on working memory in individuals with ASD. Participants (n = 38 individuals with ASD and n = 18 neurotypical [NT] university students) viewed or listened to four melodic sequences of seven randomized monosyllabic words sung by female and male instructors. To assess working memory, participants’ tasks were to sequentially recall the paired information presented within each condition. There was no significant within-group difference between both the male and female instructor conditions or the visual + auditory or auditory only melodic instruction. Although not significant, participants tended to have slightly higher mean recall for the male instructor with visual + auditory stimuli condition and lower mean recall for the female instructor with auditory only stimuli condition. There was a significant between-group difference with the NT group having greater recall accuracy than the ASD group. Regardless of group or condition, participants tended to have greater recall accuracy at primary and recency serial positions. As individuals with ASD may have unique learning challenges, information paired with music may be delivered in multi-sensory ways to increase the likelihood of recall and subsequent learning. Implications for clinical practice, limitations of the study, and suggestions for future research are provided.

The effect of music on simulated surgical performance: a systematic review

IntroductionBeneficial effects of music have been described on several cognitive domains, task performance, stress, anxiety and pain. Greater surgical skill is a factor that has been associated with improved patient outcome. The aim of this systematic review is to assess the effect of music on surgical performance.MethodsAn exhaustive literature search was performed. The following databases were searched: Embase, Medline Ovid, Web of Science, Cochrane CENTAL, PsycINFO Ovid, CINAHL EBSCOhost, ERIC EBSCOhost and Google Scholar. All prospective studies that assessed the effect of a music intervention compared to either another auditory condition or silence on surgical performance were included in a qualitative synthesis. The study was registered in the PROSPERO-database (CRD42018092021).ResultsThe literature search identified 3492 articles of which 9 studies (212 participants) were included. Beneficial effects of music were reported on time to task completion, instrument handling, quality of surgical task performance and general surgical performance. Furthermore, a beneficial effect of music on muscle activation was observed.ConclusionAlthough beneficial effects of music on surgical performance have been observed, there is insufficient evidence to definitively conclude that music has a beneficial effect on surgical performance in the simulated setting. Future studies should be conducted using greater numbers of participants focusing on a more limited range of tasks, as well as validation in the live operating environment.

Distraction and Temporal Order in Narrative Situation Models

ABSTRACTNarrative comprehension requires the allocation of resources to the construction of a situation model describing the events and circumstances in the narrative. While mind wandering, fewer resources may be devoted to this task. In the present research, we assessed whether the effects of distraction on memory for narrative event order are qualitatively similar to those of mind wandering. In two experiments, participants read passages, sometimes with auditory noise, and after each passage rated the extent to which they were on task. Both auditory noise and spontaneous mind wandering affected temporal order judgements for narrative events. However, noise also decreased on-task rating, and temporal order memory was a linear function of on-task rating regardless of auditory noise condition. We conclude that the effects of spontaneous mind wandering and auditory noise on memory for temporal order can both be understood as a withdrawal of resources devoted to situation model construction.

Loss of Vision Dominance at the Preresponse Level in Tinnitus Patients: Preliminary Behavioral Evidence.

At present, the mechanisms underlying changes in visual processing in individuals with tinnitus remain unclear. Therefore, we investigated whether the vision dominance of individuals with tinnitus disappears at the preresponse level through behavioral study. A total of 38 individuals with tinnitus and 31 healthy controls completed a task in which they were asked to attend to either visual or auditory stimuli while ignoring simultaneous stimulus inputs from the other modality. We manipulated three levels of congruency between the simultaneous visual and auditory inputs: congruent (C), incongruent at the preresponse level (PRIC), and incongruent at the response level (RIC). Thus, we differentiated the cross-modal conflict explicitly into the preresponse (PRIC > C) and response (RIC > PRIC) levels. The results revealed no significant difference in the size of the preresponse level conflict between the auditory attention and visual attention conditions in tinnitus group. In brief, the preresponse level of individuals with tinnitus showed a loss in vision dominance. This may be due to the reduced interference of visual information in auditory processing.

Intersensory redundancy promotes infant detection of prosody in infant-directed speech

Prosody, or the intonation contours of speech, conveys emotion and intention to the listener and provides infants with an early basis for detecting meaning in speech. Infant-directed speech (IDS) is characterized by exaggerated prosody, slower tempo, and elongated pauses, all amodal properties detectable across the face and voice. Although speech is an audiovisual event, it has been studied primarily as a unimodal auditory stream without the synchronized dynamic face of the speaker. According to the intersensory redundancy hypothesis, redundancy across the senses facilitates perceptual learning of amodal information, including prosody. We predicted that young infants who are still learning to discriminate and categorize prosodic information would detect prosodic changes better in the presence of intersensory redundancy (i.e., synchronous audiovisual speech) than in its absence (i.e., unimodal auditory or asynchronous audiovisual speech). To test this hypothesis, 72 4-month-old infants were habituated to recordings of women reciting passages in IDS with prosody conveying either approval or prohibition and then were tested with recordings of a novel passage with either a change or no change in prosody. Infants who received bimodal synchronous stimulation exhibited significant visual recovery to the novel passage with a change in prosody, but not to a novel passage with no change in prosody. Infants in the unimodal auditory and bimodal asynchronous conditions did not exhibit visual recovery in either condition. Results support the hypothesis that intersensory redundancy facilitates detection and abstraction of invariant prosody across changes in linguistic content and likely serves as an early foundation for the detection of meaning in fluent speech.

The effect of distractors on SSVEP-based brain-computer interfaces

Objective. This study analyses the effect of distractors on steady-state visually evoked potentials (SSVEP) to establish how these nuisance signals, typically present in the real-world, would effect an SSVEP-based brain-computer interface (BCI). The distractors introduced to the SSVEP-based experiments are auditory, visual and movement distractors, specifically selected to reflect the use of various BCIs outside the laboratory. Approach. An assessment on the influence of these nuisance signals on SSVEP data as compared to SSVEP data with no distractors is presented. This is done by examining the frequency spectrum of the SSVEP responses followed by the implementation of feature extraction techniques, specifically canonical correlation analysis (CCA) and power spectral density analysis (PSDA), and a statistical analysis on the results obtained. As an added contribution, this study is designed to have each subject repeat the same experiments on different days such that the variation in performance with and without distractors may be investigated longitudinally. Main results. The results revealed that the spectra and the classification performance of the auditory distractors condition are comparable with the no distractors condition. On the other hand, there is a decrease in the signal-to-noise ratios (SNRs) of the visual and movement distractors conditions. This is reflected with a significant decrease in the SSVEP performance of 4.29% and 12.14% for the two distractor conditions respectively compared to the no distractors condition. A significant above-chance level SSVEP performance could still be obtained with all the distractor conditions. The longitudinal analysis revealed that the difference in performance between the SSVEP experimental conditions was consistent across sessions. Significance. This study provides a comparison on the performance of an SSVEP-based BCI with various external distractors. This analysis is necessary for the transition of BCI applications to be used every day in uncontrolled environments.

Audiovisual Multisensory Integration and Evoked Potentials in Young Adults With and Without Attention-Deficit/Hyperactivity Disorder.

The purpose of this study was to assess how young adults with attention-deficit/hyperactivity disorder (ADHD) process audiovisual (AV) multisensory stimuli using behavioral and neurological measures. Adults with a clinical diagnosis of ADHD (n = 10) and neurotypical controls (n = 11) completed a simple response time task, consisting of auditory, visual, and AV multisensory conditions. Continuous 64-electrode electroencephalography (EEG) was collected to assess neurological responses to each condition. The AV multisensory condition resulted in the shortest response times for both populations. Analysis using the race model (Miller, 1982) demonstrated that those with ADHD had violation of the race model earlier in the response, which may be a marker for impulsivity. EEG analysis revealed that both groups had early multisensory integration (MSI) occur following multisensory stimulus onset. There were also significant group differences in event-related potentials (ERPs) in frontal, parietal, and occipital brain regions, which are regions reported to be altered in those with ADHD. This study presents results examining multisensory processing in the population of adults with ADHD, and can be used as a foundation for future ADHD research using developmental research designs as well as the development of novel technological supports.

Auditory cues behind congenitally blind subjects improve their balance control in bipedal upright posture

BackgroundCongenitally blind subjects developed postural adaptations improving somatosensory and vestibular systems to maintain upright stability and auditory skills to orient them in environment. However, the influence of auditory cues on upright stability in congenitally blind subjects stays unknown. Research questionThe aim of this study is to define the influence of an auditory cue in congenitally blind subjects back space on their balance posture. MethodsEleven sighted subjects and eleven congenitally blind subjects performed upright bipedal and unipedal quiet stances on a force plate with two conditions of auditory cue played by a loudspeaker placed 2 m behind them. Mean CoP velocity were recorded. Student test was used to compare significant difference between blind and sighted subjects bipedal and unipedal postures stability in both conditions of auditory cue. Results and significanceResults showed that congenitally blind subjects had no significant difference in mean sway velocity compared to sighted subjects in bipedal upright posture in auditory signal condition. However, blind subjects had significant lower mean sway velocity than sighted subjects in bipedal upright posture without sound. Blind subjects had significant increased mean sway velocity during unipedal quiet standing in both auditory cue conditions (with and without sound). The results showed that congenitally blind subjects used auditory cues placed behind them in order to improve their balance control in bipedal upright posture. In this case, blind subjects could better use compensatory mechanisms to perform quiet standing as sighted subjects. Without sound or in unipedal upright posture, congenitally blind subjects probably have sensory perturbations or limitations that impose them adaptations in order to avoid falling risk. Auditory cues should be study in the aim to better understand the compensatory mechanisms used by congenitally blind subjects to perform postural balance in usual environment.

Sustained attention in sensory modulation disorder and attention deficit/hyperactivity disorder

BackgroundThere are high comorbidity rates between sensory modulation disorder (SMD) and attention deficit hyperactivity disorder (ADHD). Knowledge regarding the objective neuropsychological differentiation between them is scarce. AimThis study examines the effects of SMD and ADHD on a sustained attention task with and without aversive auditory conditions. MethodSixty six young adult females were tested on the Conjunctive - Continuous Performance Task-Visual (CCPT-V) measuring sustained attention, under two conditions: 1) aversive condition (with the three most aversive sounds chosen by the participant), and 2) non-aversive condition (without sounds). ResultsBoth the SMD and ADHD factors exhibited performance deficits in the sustained attention task. All study participants performed worse on both sustained attention and speed of processing when aversive sounds were present. ConclusionWe conclude that impaired sustained attention cannot differentiate between SMD and ADHD. Hence, these results should be taken under consideration in the assessment process of ADHD vs. SMD.

Effect of simultaneous lip-tube and auditory feedback perturbations

In a series of previous experiments, it has been shown that when required to produce the back rounded vowel /u/ with a lip-tube perturbation that prevents lip rounding, speakers reached the auditory goal associated with /u/ by altering their tongue position. In the present study, the importance of sensory feedback was further investigated by combining lip-tube and auditory feedback perturbations. Fifteen adult francophone speakers produced 5 blocks of ten /u/ tokens under various conditions (following and preceding a baseline condition). First, tokens were produced when the speakers had a lip-tube in place (predicted to increase F1 and F2) as well as a real-time auditory feedback perturbation (designed to cancel the acoustic effects of the lip-tube, that is, to decrease F2 and F1). Next, only the lip-tube perturbation was applied, with and without white noise. Formant values for each condition were extracted at the vowel midpoint. Although most speakers produced a larger compensatory response with the lip-tube alone condition than with the combined lip-tube and auditory perturbation condition, all speakers produced altered formants in the latter condition. This suggests that speakers try to reduce auditory and somatosensory feedback errors during speech production, with a speaker-specific weighting of each sensory modality.

The roles of musical expertise and sensory feedback in beat keeping and joint action

Auditory feedback of actions provides additional information about the timing of one’s own actions and those of others. However, little is known about how musicians and nonmusicians integrate auditory feedback from multiple sources to regulate their own timing or to (intentionally or unintentionally) coordinate with a partner. We examined how musical expertise modulates the role of auditory feedback in a two-person synchronization–continuation tapping task. Pairs of individuals were instructed to tap at a rate indicated by an initial metronome cue in all four auditory feedback conditions: no feedback, self-feedback (cannot hear their partner), other feedback (cannot hear themselves), or full feedback (both self and other). Participants within a pair were either both musically trained (musicians), both untrained (nonmusicians), or one musically trained and one untrained (mixed). Results demonstrated that all three pair types spontaneously synchronized with their partner when receiving other or full feedback. Moreover, all pair types were better at maintaining the metronome rate with self-feedback than with no feedback. Musician pairs better maintained the metronome rate when receiving other feedback than when receiving no feedback; in contrast, nonmusician pairs were worse when receiving other or full feedback compared to no feedback. Both members of mixed pairs maintained the metronome rate better in the other and full feedback conditions than in the no feedback condition, similar to musician pairs. Overall, nonmusicians benefited from musicians’ expertise without negatively influencing musicians’ ability to maintain the tapping rate. One implication is that nonmusicians may improve their beat-keeping abilities by performing tasks with musically skilled individuals.

Cognitive Load and Situation Awareness for Soldiers: Effects of Message Presentation Rate and Sensory Modality.

We sought to determine the influence of message presentation rate (MPR) and sensory modality on soldier cognitive load. Soldiers commonly communicate tactical information by radio. The Canadian Army is equipping soldiers with a battle management system (BMS), which also allows them to communicate by text. We varied presentation modality (auditory vs. visual) and MPR (fast or slow) in an experiment involving a tactical scenario. Participants (soldiers) received messages and periodically provided situation reports to higher level command, and the scored reports were used to provide a measure of situation awareness (SA). The detection response task (DRT) and NASA-TLX were used to measure cognitive load. The fast MPR reduced DRT accuracy and increased response times relative to slow MPR. The NASA-TLX results also showed higher subjective workload ratings for several subscales with fast MPR. Messages presented visually produced greater cognitive load, with slower DRT response times for the visual than the auditory condition. SA scores were higher with slower MPR and auditory presentation. There was no statistical interaction of presentation modality and rate for any measure. Fast MPR and visual presentation increased cognitive load and degraded SA. These findings show that the DRT can be used to measure workload effectively in a tactical military context and that the method of information presentation affects how soldiers process information in a BMS.