Cognitive Resource Allocation Research Articles

The impact of stress on the risk decision-making process.

The effect of stress on risk-taking or risk-averse behavior in decision-making has been inconclusive in previous research, with few studies revealing the underlying neural mechanisms. This study employed event-related potentials technique and combined a social cold pressor assessment test with a mental arithmetic task to induce stress responses, aiming to investigate the influence of exogenous stress on the risk decision-making process. Stress induction results indicated that, in addition to raising heart rate and blood pressure, stress responses were accompanied by enhanced negative emotions, diminished positive emotions, and alterations in neural activity. The outcomes of risk decision-making showed that stress did not significantly affect risk preference or time of choice but did reduce the feedback-related negativity/reward positivity, with a particularly significant effect observed for large outcomes. Stress also altered the amplitude of the P3 component, with stress decreasing the P3 value for winning outcomes relative to losing outcomes. The study suggests that understanding how stress affects risk preference should consider the emotional valence induced by stress. Contrary to the reward sensitivity hypothesis, stress weakened reward sensitivity. Stress led to changes in the allocation of cognitive resources for outcome evaluation: compared to negative outcomes, stress reduced cognitive resources for positive outcomes, which might be related to the enhanced negative emotions induced by stress. The study highlights the importance of focusing on the subjective emotional experience induced by stress in future research on stress and risk decision-making.

Modeling distracted driving behavior considering cognitive processes

The modeling of distracted driving behavior has been studied for many years, however, there remain many distraction phenomena that can not be fully modeled. This study proposes a new method that establishes the model using the queuing network model human processor (QN-MHP) framework. Unlike previous models that only consider distracted-driving-related human factors from a mathematical perspective, the proposed method reflects the information processing in the human brain, and simulates the distracted driver’s cognitive processes based on a model structure supported by physiological and cognitive research evidence. Firstly, a cumulative activation effect model for external stimuli is adopted to mimic the phenomenon that a driver responds only to stimuli above a certain threshold. Then, dual-task queuing and switching mechanisms are modeled to reflect the cognitive resource allocation under distraction. Finally, the driver's action is modeled by the Intelligent Driver Model (IDM). The model is developed for visual distraction auditory distraction separately. 773 distracted car-following events from the Shanghai Naturalistic Driving Study data were used to calibrate and verify the model. Results show that the model parameters are more uniform and reasonable. Meanwhile, the model accuracy has improved by 57% and 66% compared to the two baseline models respectively. Moreover, the model demonstrates its ability to generate critical pre-crash scenarios and estimate the crash rate of distracted driving. The proposed model is expected to contribute to safety research regarding new vehicle technologies and traffic safety analysis.

Changes in visually and auditory attended audiovisual speech processing in cochlear implant users: A longitudinal ERP study

Limited auditory input, whether caused by hearing loss or by electrical stimulation through a cochlear implant (CI), can be compensated by the remaining senses. Specifically for CI users, previous studies reported not only improved visual skills, but also altered cortical processing of unisensory visual and auditory stimuli. However, in multisensory scenarios, it is still unclear how auditory deprivation (before implantation) and electrical hearing experience (after implantation) affect cortical audiovisual speech processing.Here, we present a prospective longitudinal electroencephalography (EEG) study which systematically examined the deprivation- and CI-induced alterations of cortical processing of audiovisual words by comparing event-related potentials (ERPs) in postlingually deafened CI users before and after implantation (five weeks and six months of CI use). A group of matched normal-hearing (NH) listeners served as controls. The participants performed a word-identification task with congruent and incongruent audiovisual words, focusing their attention on either the visual (lip movement) or the auditory speech signal. This allowed us to study the (top-down) attention effect on the (bottom-up) sensory cortical processing of audiovisual speech.When compared to the NH listeners, the CI candidates (before implantation) and the CI users (after implantation) exhibited enhanced lipreading abilities and an altered cortical response at the N1 latency range (90–150 ms) that was characterized by a decreased theta oscillation power (4–8 Hz) and a smaller amplitude in the auditory cortex. After implantation, however, the auditory-cortex response gradually increased and developed a stronger intra-modal connectivity. Nevertheless, task efficiency and activation in the visual cortex was significantly modulated in both groups by focusing attention on the visual as compared to the auditory speech signal, with the NH listeners additionally showing an attention-dependent decrease in beta oscillation power (13–30 Hz).In sum, these results suggest remarkable deprivation effects on audiovisual speech processing in the auditory cortex, which partially reverse after implantation. Although even experienced CI users still show distinct audiovisual speech processing compared to NH listeners, pronounced effects of (top-down) direction of attention on (bottom-up) audiovisual processing can be observed in both groups. However, NH listeners but not CI users appear to show enhanced allocation of cognitive resources in visually as compared to auditory attended audiovisual speech conditions, which supports our behavioural observations of poorer lipreading abilities and reduced visual influence on audition in NH listeners as compared to CI users.

Involvement of the anterior insula and frontal operculum during wh-question comprehension of wh-in-situ Korean language.

In this research, we employed functional magnetic resonance imaging (fMRI) to examine the neurological basis for understanding wh-questions in wh-in-situ languages such as Korean, where wh-elements maintain their original positions instead of moving explicitly within the sentence. Our hypothesis centered on the role of the salience and attention network in comprehending wh-questions in wh-in-situ languages, such as the discernment of wh-elements, the demarcation between interrogative types, and the allocation of cognitive resources towards essential constituents vis-à-vis subordinate elements in order to capture the speaker's communicative intent. We explored subject and object wh-questions and scrambled wh-questions, contrasting them with yes/no questions in Korean. Increased activation was observed in the left anterior insula and bilateral frontal operculum, irrespective of the wh-position or scrambling of wh-element. These results suggest the interaction between the salience and attentional system and the syntactic linguistic system, particularly the left anterior insula and bilateral frontal operculum, in comprehending wh-questions in wh-in-situ languages.

Effects of Background Noise and Linguistic Violations on Frontal Theta Oscillations During Effortful Listening.

Background noise and linguistic violations have been shown to increase the listening effort. The present study aims to examine the effects of the interaction between background noise and linguistic violations on subjective listening effort and frontal theta oscillations during effortful listening. Thirty-two normal-hearing listeners participated in this study. The linguistic violation was operationalized as sentences versus random words (strings). Behavioral and electroencephalography data were collected while participants listened to sentences and strings in background noise at different signal to noise ratios (SNRs) (-9, -6, -3, 0 dB), maintained them in memory for about 3 sec in the presence of background noise, and then chose the correct sequence of words from a base matrix of words. Results showed the interaction effects of SNR and speech type on effort ratings. Although strings were inherently more effortful than sentences, decreasing SNR from 0 to -9 dB (in 3 dB steps), increased effort rating more for sentences than strings in each step, suggesting the more pronounced effect of noise on sentence processing that strings in low SNRs. Results also showed a significant interaction between SNR and speech type on frontal theta event-related synchronization during the retention interval. This interaction indicated that strings exhibited higher frontal theta event-related synchronization than sentences at SNR of 0 dB, suggesting increased verbal working memory demand for strings under challenging listening conditions. The study demonstrated that the interplay between linguistic violation and background noise shapes perceived effort and cognitive load during speech comprehension under challenging listening conditions. The differential impact of noise on processing sentences versus strings highlights the influential role of context and cognitive resource allocation in the processing of speech.

Health involvement modulates physician preference in the brain during online health consultation

In traditional offline health-seeking behavior, patients consistently exhibit a preference for similar types of physicians due to limited access to physicians’ information. Nevertheless, with the advent of online health consultation platforms offering comprehensive physicians’ information for patients, raises the question: do patients continue to exhibit uniform preference for physicians? To address this issue, we first employed a behavioral experiment to discern patients’ preferences for different types of physicians’ information under different health involvement, and then conducted a functional magnetic resonance imaging (fMRI) experiment to furnish neural/physiological evidence. The results showed that health involvement modulates patients’ preferences, when health involvement was low, patients had diverse preferences for physicians, that is, different types of physicians’ information could individually impact patients’ choice and could serve as substitutes for each other. When health involvement was high, patients’ preference for physicians were uniform, highlighting that the collective influence of different types of physicians’ information on patients’ choice behavior. From the neural level, an explanation for the results was that the ventromedial prefrontal cortex (VMPFC) and ventral striatum (VS) brain regions, two key brain regions reflecting individual cognitive resource allocation, had different activation levels under different health involvement, indicating that patients allocated different cognitive resources.

UNRAVELING THE COGNITIVE MECHANISM OF EMOTIONAL VALIDITY IN CONFLICT CONTROL

Understanding the cognitive mechanisms underlying emotional validity in conflict control is crucial for elucidating how emotions influence decision-making and cognitive processing. Emotional validity refers to the congruence between emotional cues and task demands, impacting the allocation of attention and cognitive resources during conflict resolution. This paper reviews current research investigating the neural correlates and behavioral effects of emotional validity on conflict control processes. It examines how emotional stimuli modulate attentional bias, response inhibition, and cognitive flexibility through interactions with brain regions implicated in emotion regulation and cognitive control. Furthermore, the paper discusses implications for cognitive theories of emotion-cognition interaction and potential applications in clinical and real-world settings.

Jointly Active/Passive Beamforming Optimization for Intelligent-Reflecting Surface-Assisted Cognitive-IoT Networks

To overcome challenges such as limited energy availability for terminal devices, constrained network coverage, and suboptimal spectrum resource utilization, with the overarching objective of establishing a sustainable and efficient interconnection infrastructure, we introduce an innovative Intelligent Reflective Surface (IRS) technology. This cutting-edge IRS technology is employed to architect a wireless and energy-efficient cognitive secure communication network assisted by IRS. To further optimize the overall energy harvesting of this network, we present a cognitive secure resource allocation scheme, aiming to maximize the system’s total collected energy. This scheme carefully considers various constraints, including transmission power constraints for cognitive base stations, power constraints for jammer devices, interference limitations for all primary users, minimum security rate constraints for all cognitive Internet of Things (IoT) devices, and phase shift constraints for IRS. We establish a comprehensive hybrid cognitive secure resource allocation model, encompassing joint cognitive transmission beam design, jammer device transmission beam design, and phase shift design. Given the non-convex nature of the formulated problem and the intricate coupling relationships among variables, we devise an effective block coordinate descent (BCD) iterative algorithm. The realization of joint cognitive/jammer base station transmission beam design and phase shift design employs sophisticated techniques such as continuous convex approximation methods and semi-definite programming. Simulation results underscore the superior performance of the proposed scheme compared to existing resource allocation approaches, particularly in terms of total harvested energy and other critical metrics.

A new EEG neurofeedback training approach in sports: the effects function-specific instruction of Mu rhythm and visuomotor skill performance.

Achieving optimal visuomotor performance in precision sports relies on maintaining an optimal psychological state during motor preparation. To uncover the optimal psychological state, extensive EEG studies have established a link between the Mu rhythm (8-13 Hz at Cz) and cognitive resource allocation during visuomotor tasks (i.e., golf or shooting). In addition, the new approach in EEG neurofeedback training (NFT), called the function-specific instruction (FSI) approach, for sports involves providing function-directed verbal instructions to assist individuals to control specific EEG parameters and align them with targeted brain activity features. While this approach was initially hypothesized to aid individuals in attaining a particular mental state during NFT, the impact of EEG-NFT involving Mu rhythm on visuomotor performance, especially when contrasting the traditional instruction (TI) approach with the FSI approach, underscores the necessity for additional exploration. Hence, the objective of this study is to investigate the impact of the FSI approach on modulating Mu rhythm through EEG-NFT in the context of visuomotor performance. Thirty novice participants were recruited and divided into three groups: function-specific instruction (FSI, four females, six males; mean age = 27.00 ± 7.13), traditional instruction (TI, five females, five males; mean age = 27.00 ± 3.88), and sham control (SC, five females, five males; mean age = 27.80 ± 5.34). These groups engaged in a single-session EEG-NFT and performed golf putting tasks both before and after the EEG-NFT. The results showed that within the FSI group, single-session NFT with augmented Mu power led to a significant decrease in putting performance (p = 0.013). Furthermore, we noted a marginal significance indicating a slight increase in Mu power and a reduction in the subjective sensation of action control following EEG-NFT (p = 0.119). While there was a positive correlation between Mu power and mean radial error in golf putting performance (p = 0.043), it is important to interpret this relationship cautiously in the context of reduced accuracy in golf putting. The findings emphasize the necessity for extended investigation to attain a more profound comprehension of the nuanced significance of Mu power in visuomotor performance. The study highlights the potential effectiveness of the FSI approach in EEG-NFT and in enhancing visuomotor performance, but it also emphasizes the potential impact of skill level and attentional control, particularly in complex visuomotor tasks.

Allocation of cognitive resources for older adults with normal or impaired hearing when listening to temporally degraded and masked speech

Hearing impairment may affect how older listeners allocate cognitive resources when communicating in challenging environments. Older adults with normal or impaired hearing completed three speech recognition studies. The studies consisted of 15-16 measures of temporally filtered speech with (1) degraded spectral cues, (2) competing speech-modulated noise, and (3) speech vocoding in speech-modulated noise. Generalization was assessed with measures of speech interruption, segregation, and multitalker masking. To account for audibility differences, all listeners received spectral shaping fit to their hearing thresholds. Measures in each study were reduced to a single principal component (PC) that represented speech recognition abilities. Participants also completed a cognitive test battery that yielded domain-specific PCs and a measure of speech glimpsing. For each study, hierarchical linear regression analysis was completed separately for subgroups of older adults with normal or impaired hearing using cognitive PCs as predictor variables, followed by speech glimpsing, age, and hearing thresholds. Vocabulary knowledge was the best predictor of speech recognition for older adults with normal hearing, whereas working memory consistently explained ∼30%-40% of the variance in recognition for older adults with hearing loss. Thus, even with sufficient audibility, hearing impairment may alter allocation of cognitive resources for older adults listening to degraded speech.

Effects of the BalanCI on Working Memory and Balance in Children and Young Adults With Cochleovestibular Dysfunction.

This study aimed to: (1) determine the interaction between cognitive load and balance in children and young adults with bilateral cochleovestibular dysfunction who use bilateral cochlear implants (CIs) and (2) determine the effect of an auditory balance prosthesis (the BalanCI) on this interaction. Many (20 to 70%) children with sensorineural hearing loss experience some degree of vestibular loss, leading to poorer balance. Poor balance could have effects on cognitive resource allocation which might be alleviated by the BalanCI as it translates head-referenced cues into electrical pulses delivered through the CI. It is hypothesized that children and young adults with cochleovestibular dysfunction will demonstrate greater dual-task costs than typically-developing children during dual balance-cognition tasks, and that BalanCI use will improve performance on these tasks. Study participants were 15 typically-developing children (control group: mean age ± SD = 13.6 ± 2.75 years, 6 females) and 10 children and young adults who use bilateral CIs and have vestibular dysfunction (CI-V group: mean age ± SD=20.6 ± 5.36 years, 7 females). Participants completed two working memory tasks (backward auditory verbal digit span task and backward visuospatial dot matrix task) during three balance conditions: seated, standing in tandem stance with the BalanCI off, and standing in tandem stance with the BalanCI on. Working memory performance was quantified as total number of correct trials achieved. Postural stability was quantified as translational and rotational path length of motion capture markers worn on the head, upper body, pelvis, and feet, normalized by trial time. Relative to the control group, children and young adults in the CI-V group exhibited poorer overall working memory across all balance conditions ( p = 0.03), poorer translational postural stability (larger translational path length) during both verbal and visuospatial working memory tasks ( p < 0.001), and poorer rotational stability (larger rotational path length) during the verbal working memory task ( p = 0.026). The CI-V group also exhibited poorer translational ( p = 0.004) and rotational ( p < 0.001) postural stability during the backward verbal digit span task than backward visuospatial dot matrix task; BalanCI use reduced this stability difference between verbal and visuospatial working memory tasks for translational stability overall ( p > 0.9), as well as for rotational stability during the maximum working memory span (highest load) participants achieved in each task ( p = 0.91). Balance and working memory were impaired in the CI-V group compared with the control group. The BalanCI offered subtle improvements in stability in the CI-V group during a backward verbal working memory task, without producing a negative effect on working memory outcomes. This study supports the feasibility of the BalanCI as a balance prosthesis for individuals with cochleovestibular impairments.

Dual tasking in individuals with post-stroke aphasia: a scoping review protocol.

The purpose of this scoping review is to identify the main theoretical frameworks being used to explain dual-task performance deficits in people with post-stroke aphasia, identify the domains of function being measured and the assessments being used, highlight current interventions to improve dual-task performance, and identify the gaps in the current body of literature on dual tasking and aphasia. Post-stroke aphasia can lead to challenges across all activities of daily living. However, little is known about how a stroke and co-occurring language impairment may affect the allocation of cognitive resources, particularly in dual-task conditions. This vital information will allow researchers and clinicians to develop more effective interventions to combat the effects of the infarct. To be considered in the review, articles must (i) be written in English, (ii) include individuals at least 6 months post stroke, (iii) include adults with aphasia (with data presented separately from other populations), and (iv) include measures of dual-task performance. This review will be conducted in line with the JBI methodology for scoping reviews. A search of Linguistics and Language Behavior Abstracts, PsycINFO, Communication Mass Media Complete, PubMed, CINAHL Plus, ScienceDirect, and the Cochrane Library will be undertaken to identify publications on the topic. Results will be restricted to sources that meet the inclusion/exclusion criteria. Data will be extracted from included papers by up to 3 independent reviewers using a data extraction tool developed by the reviewers. The results will be presented as a narrative summary, accompanied by charted results as appropriate. DOI:10.17605/OSF.IO/2YX76.

To remember or not to remember: Neural oscillations and ERPs as predictors of intentional associative fear learning

It is widely accepted that impaired safety learning to a safe stimulus is a pathological feature of anxiety disorders. Safety learning refers to learning that a stimulus is associated with the absence of threat. Cognitive mechanisms that underlie successful threat and safety learning are, however, poorly understood. This study aimed to identify various physiological markers, including neural oscillations and event-related potentials (ERPs) that predict successful threat and safety learning. Therefore, to detect potential differences in these markers, we measured EEG in a fear learning framework combined with a subsequent memory paradigm. Thirty-seven participants were asked to memorize a series of associations between faces and an aversive unconditioned stimulus (US) or its omission. We found a decrease of power in the alpha band in occipital brain regions during learning for both threatening (conditioned stimuli, CS+) and safe faces (control stimuli, CS−) that were subsequently remembered to be associated with a US or not. No effects in theta band were found. In regard to ERPs, a late positive potential (LPP) and a P300 component were larger for remembered than for forgotten CS-US associations. The P300 was also enhanced to remembered US and US omissions, thus replicating previous findings. These results point to the importance of cognitive resource allocation as an underlying mechanism of fear learning and electrophysiological measurements as potential biomarkers for successful threat and safety learning.

Objective Measure of Listening Effort in HearingImpaired Individuals With and Without Tinnitus.

Tinnitus is a perception of sound in the brain without any external stimulus. Tinnitus patients often complain of more efforts required in listening. They may be ineffective in inhibiting their attention, driven to irrelevant ringing sounds in their ear rather than attending to the relevant target speech stimulus. The study's objective was to evaluate an allocation of cognitive resources among tinnitus patients for concurrent tasks required for understanding speech using an objective dual-task paradigm to assess listening effort. We recruited 40 participants with mild to moderately severe sloping sensorineural hearing loss within 60-70 years. They were subgrouped into control and clinical groups. The clinical group had a severe degree of tonal tinnitus bilaterally. The objective listening task used listening effort, and a subjective questionnaire to assess the effort in listening was assessed by each study participant. The results indicated poorer recognition and reduced recall scores in a clinical group than the control group in each signal-to-noise ratio. The recall score in objective listening effort measurement was strongly correlated with subjective questions assessed effort in listening among the clinical group at each signal-to-noise ratio. However, in the control group, the correlation was to a mild degree at 0 dB signal-to-noise ratio only. Annoyance caused by tinnitus disrupts attention, thereby limiting the effective use of cognitive resources for concurrent speech processing and recalling reflected in the listening effort task.

Boosting serotonin increases information gathering by reducing subjective cognitive costs.

Serotonin is implicated in the valuation of aversive costs, such as delay or physical effort. However, its role in governing sensitivity to cognitive effort, for example deliberation costs during information gathering, is unclear. We show that treatment with a serotonergic antidepressant in healthy human individuals of either sex enhances a willingness to gather information when trying to maximize reward. Using computational modelling, we show this arises from a diminished sensitivity to subjective deliberation costs during the sampling process. This result is consistent with the notion that serotonin alleviates sensitivity to aversive costs in a domain-general fashion, with implications for its potential contribution to a positive impact on motivational deficits in psychiatric disorders.SIGNIFICANCE STATEMENT:Gathering information about the world is essential for successfully navigating it. However, sampling information is costly, and we need to balance between gathering too little and too much information. The neurocomputational mechanisms underlying this arbitration between a putative gain, such as reward, and the associated costs, such as allocation of cognitive resources, remain unclear. In this study, we show that week-long daily treatment with a serotonergic antidepressant enhances a willingness to gather information when trying to maximize reward. Computational modelling indicates this arises from a reduced perception of aversive costs, rendering information gathering less cognitively effortful. This finding points to a candidate mechanism by which serotonergic treatment might help alleviate motivational deficits in a range of mental illnesses.

The role of focus back effort in the relationships among motivation, interest, and mind wandering: an individual difference perspective

Considerable research suggests a link between mind wandering and diminished levels of motivation and interest. During episodes of mind wandering, individuals may engage in efforts to redirect their attention back to the task at hand (known as focus back effort). Building on the resource-control hypothesis, we hypothesized that the influence of interest and motivation on mind wandering may be mediated by focus back effort. In Study 1, we employed a latent-variable approach to investigate these relationships across three tasks with varying cognitive demands. The results showed that individual differences in interest indirectly influenced mind wandering through the mediating factors of motivation and focus back effort. Furthermore, individual differences in interest indirectly predicted task performance through the mediating factors of motivation, focus back effort, and mind wandering during the high-load task. In Study 2, we replicated the relationships among these factors in a reading comprehension task. The results consistently support the role of focus back effort as an adaptive mechanism for executive control, enabling the allocation of cognitive resources to both mind wandering and task performance. These findings underscore the significance of focus back effort in elucidating the interplay between mind wandering, motivation, interest, and task performance. Importantly, our results align with the resource-control theory.

The impact of linguistic metaphor on translation unit in target text processing: An eye tracking and keylogging English-Chinese translation study

This study attempts to explore the effect of linguistic metaphors on translation unit (TU) during target text (TT) processing in English to Chinese translation based on the concept and model of attention unit (AU) (Hvelplund, 2011). Four eye-key indicators are examined in this research for cognitive load measurement: Total Attentional Duration (TA duration), AU count, AU duration and pupil dilation. Twenty-four student translators were asked to translate texts containing literal expressions without metaphor, linguistic metaphors with fixed expressions in target language (TL) and linguistic metaphors without fixed expressions in target language (TL). The results of statistical analysis suggest that text type plays a certain role in cognitive resource allocation, although indicators of eye tracking and keylogging do not always point to a same direction. The research outcome, especially the findings on the relationship between the type of linguistic metaphor and cognitive effort, provide empirical support for Schaeffer et al. (2016)'s notion of interim representation in the production process of linguistic metaphor translation.

Allocation of cognitive resources in cognitive processing of rhythmic visual stimuli before gait-related motor initiation.

Rhythmic visual cues can affect the allocation of cognitive resources during gait initiation (GI) and motor preparation. However, it is unclear how the input of rhythmic visual information modulates the allocation of cognitive resources and affects GI. The purpose of this study was to explore the effect of rhythmic visual cues on the dynamic allocation of cognitive resources by recording electroencephalographic (EEG) activity during exposure to visual stimuli. This study assessed event-related potentials (ERPs), event-related synchronization/desynchronization (ERS/ERD), and EEG microstates at 32 electrodes during presentation of non-rhythmic and rhythmic visual stimuli in 20 healthy participants. The ERP results showed that the amplitude of the C1 component was positive under exposure to rhythmic visual stimuli, while the amplitude of the N1 component was higher under exposure to rhythmic visual stimuli compared to their non-rhythmic counterparts. Within the first 200 ms of the onset of rhythmic visual stimuli, ERS in the theta band was highly pronounced in all brain regions analyzed. The results of microstate analysis showed that rhythmic visual stimuli were associated with an increase in cognitive processing over time, while non-rhythmic visual stimuli were associated with a decrease. Overall, these findings indicated that, under exposure to rhythmic visual stimuli, consumption of cognitive resources is lower during the first 200 ms of visual cognitive processing, but the consumption of cognitive resources gradually increases over time. After approximately 300 ms, cognitive processing of rhythmic visual stimuli consumes more cognitive resources than processing of stimuli in the non-rhythmic condition. This indicates that the former is more conducive to the completion of gait-related motor preparation activities, based on processing of rhythmic visual information during the later stages. This finding indicates that the dynamic allocation of cognitive resources is the key to improving gait-related movement based on rhythmic visual cues.

Dual-task walking on real-world surfaces: Adaptive changes in walking speed, step width and step height in young and older adults

ObjectivesAge-related changes in dual-task walking are well established, but research in this topic is based on evidence from laboratory rather than real-world studies. We investigated how dual-task walking on real-world surfaces affects young and older adults' gait characteristics and cognitive resource allocation. MethodSixteen young (aged 19–35, 12 female) and fifteen older adults (aged 70–85, 7 female) with no major neurological or musculoskeletal disorders walked at a self-selected speed on forty-metre outdoor paths that had asphalt or grass surface. They walked with or without a cognitive task (counting backwards). Cognitive task difficulty was individually adjusted at 80 % accuracy. Participants performed the three tasks in Single Task (ST Asphalt, ST Grass, ST Cognitive) and Dual Task context (DT Asphalt-Cognitive, DT Grass-Cognitive). ResultsThe two groups showed similar dual task effects in cognition and walking speed, both of which were slower when dual-task walking. Older adults' steps were wider overall but only young adults widened their step width when dual-task walking on grass compared to asphalt. Similarly, young adults' step height increased from single to dual-task walking when on grass, where older adults' did not. DiscussionThe lack of adaptation of step width and height when dual-task walking may leave older adults vulnerable to tripping or falling in common real-world conditions, such as while walking on grass, gravel, or uneven city sidewalks. Considering this, the built environment should be made more accessible to facilitate older adults' safe walking.

Prefrontal transcranial direct current stimulation over the right prefrontal cortex reduces proactive and reactive control performance towards emotional material in healthy individuals

The prefrontal cortex plays a crucial role in cognitive processes, both during anticipatory and reactive modes of cognitive control. Transcranial Direct Current Stimulation (tDCS) can modulate these cognitive resources. However, there is a lack of research exploring the impact of tDCS on emotional material processing in the prefrontal cortex, particularly in regard to proactive and reactive modes of cognitive control. In this study, 35 healthy volunteers underwent both real and sham tDCS applied to the right prefrontal cortex in a counterbalanced order, and then completed the Cued Emotion Control Task (CECT). Pupil dilation, a measure of cognitive resource allocation, and behavioral outcomes, such as reaction time and accuracy, were collected. The results indicate that, as compared to sham stimulation, active right-sided tDCS reduced performance and resource allocation in both proactive and reactive modes of cognitive control. These findings highlight the importance of further research on the effects of tDCS applied to the right prefrontal cortex on cognitive engagement, particularly for clinical trials utilizing the present electrode montage in combination with cognitive interventions.