Low Cognitive Load Conditions Research Articles

Sleep Fragmentation Modulates the Neurophysiological Correlates of Cognitive Fatigue.

Cognitive fatigue (CF) is a critical factor affecting performance and well-being. It can be altered in suboptimal sleep quality conditions, e.g., in patients suffering from obstructive sleep apnea who experience both intermittent hypoxia and sleep fragmentation (SF). Understanding the neurophysiological basis of SF in healthy individuals can provide insights to improve cognitive functioning in disrupted sleep conditions. In this electroencephalographical (EEG) study, we investigated in 16 healthy young participants the impact of experimentally induced SF on the neurophysiological correlates of CF measured before, during, and after practice on the TloadDback, a working memory task tailored to each individual's maximal cognitive resources. The participants spent three consecutive nights in the laboratory two times, once in an undisrupted sleep (UdS) condition and once in an SF condition induced by non-awakening auditory stimulations, counterbalanced and performed the TloadDback task both in a high (HCL) and a low (LCL) cognitive load condition. EEG activity was recorded during wakefulness in the 5 min resting state immediately before and after, as well as during the 16 min of the TloadDback task practice. In the high cognitive load under a sleep-fragmentation (HCL/SF) condition, high beta power increased during the TloadDback, indicating heightened cognitive effort, and the beta and alpha power increased in the post- vs. pre-task resting state, suggesting a relaxation rebound. In the low cognitive load/undisturbed sleep (LCL/UdS) condition, low beta activity increased, suggesting a relaxed focus, as well as mid beta activity associated with active thinking. These findings highlight the dynamic impact of SF on the neurophysiological correlates of CF and underscore the importance of sleep quality and continuity to maintain optimal cognitive functioning.

Brain correlates of attentional load processing reflect degree of bilingual engagement: Evidence from EEG

The present study uses electroencephalography (EEG) with an N-back task (0-, 1-, and 2-back) to investigate if and how individual bilingual experiences modulate brain activity and cognitive processes. The N-back is an especially appropriate task given recent proposals situating bilingual effects on neurocognition within the broader attentional control system (Bialystok and Craik, 2022). Beyond its working memory component, the N-Back task builds in complexity incrementally, progressively taxing the attentional system. EEG, behavioral and language/social background data were collected from 60 bilinguals. Two cognitive loads were calculated: low (1-back minus 0-back) and high (2-back minus 0-back). Behavioral performance and brain recruitment were modeled as a function of individual differences in bilingual engagement. We predicted task performance as modulated by bilingual engagement would reflect cognitive demands of increased complexity: slower reaction times and lower accuracy, and increase in theta, decrease in alpha and modulated N2/P3 amplitudes. The data show no modulation of the expected behavioral effects by degree of bilingual engagement. However, individual differences analyses reveal significant correlations between non-societal language use in Social contexts and alpha in the low cognitive load condition and age of acquisition of the L2/2L1 with theta in the high cognitive load. These findings lend some initial support to Bialystok and Craik (2022), showing how certain adaptations at the brain level take place in order to deal with the cognitive demands associated with variations in bilingual language experience and increases in attentional load. Furthermore, the present data highlight how these effects can play out differentially depending on cognitive testing/modalities – that is, effects were found at the TFR level but not behaviorally or in the ERPs, showing how the choice of analysis can be deterministic when investigating bilingual effects.

Using narrative 360° video as a tool to promote breast self-examination

This experiment examined the feasibility of 360° video as a tool for public health messaging by investigating the effect that viewing the 360° documentary The Waiting Room VR had on female viewers’ sense of identification, attitudes to breast cancer screening and mortality salience. A key part of the documentary places participants in a viewpoint ambiguously aligned to that of the film’s director and subject, Victoria Mapplebeck (VM), in a scene that recreates her radiotherapy treatment for breast cancer. Eighty female participants watched the documentary either sitting upright with the chair back set at a 90° angle or reclining with the chair back set at a 140° angle (consistent with VMs posture) under conditions of either high or low cognitive load. The effect of posture type was measured explicitly using questionnaires on presence, identification and breast self-examination (BSE) intention as well as implicitly using a lexical decision task to measure death-thought awareness (DTA). Reclined posture led to a higher sense of spatial presence but no increase in identification with VM. Significantly increased identification with VM led to greater intention to conduct BSE. There were no effects of posture, cognitive load or identification on DTA. The implications of these results for using 360° video as a behaviour change tool, the effects of the COVID-19 pandemic on the terror management manipulation and the relevance of spatial viewpoint in 360° video are discussed.

Storage interference in working memory cannot be removed by attention

In the present study, we examined the hypothesis that the storage interference in working memory can be removed by attention. A dual-task paradigm was employed in Experiment 1 and 2, in which participants performed a color memory task and an RSVP letter detection task concurrently. The cognitive load of the RSVP letter detection task and the storage interference caused by the RSVP letter detection task was manipulated independently. That is, the produced storage-interference difference between the low and high interference conditions was comparable between the low and high cognitive load conditions, whereas the available attentional resources were different under the two cognitive load conditions. Since there were more attentional resources in the low load condition, the removal hypothesis predicts that differences in recall performance between the low and high interference conditions should be larger in high load than in low load, i.e., there would be an interaction between load and interference. However, the results of the two experiments did not show such an interaction. In Experiment 3, we manipulated the time available for the removal mechanism to work while inducing both the storage interference and processing interference. The results showed no sign of interference removal. Thus, the present results provided solid evidence to challenge the removal hypothesis.

The benefits of mind wandering on a naturalistic prospective memory task

Mind wandering (MW) occurs when our attention spontaneously shifts from the task at hand to inner thoughts. MW is often future-oriented and may help people remember to carry out their planned actions (Prospective Memory, PM). Past-oriented MW might also play a critical role in boosting PM performance. Sixty participants learned 24 PM items and recalled them during an immersive virtual walk in a town. The items were divided into event-based—EB and time-based—TB. During the PM retention phase, participants were randomly assigned to a high or a low cognitive load condition, in order to manipulate MW frequency. Some PM items were encoded before this MW manipulation (pre-PM) and some during the virtual walk (post-PM). A high MW frequency was linked with better global PM performances. Spontaneous past-oriented MW predicted better pre-EB retrospective PM retrieval, while spontaneous future-oriented MW predicted better Pre-EB prospective PM retrieval. Voluntary future-oriented MW predicted better post-EB retrospective retrieval. We highlighted, for the first time, a differential impact of spontaneous MW content depending on the PM component (retrospective or prospective). Past‐oriented MW is crucial for (re)consolidating PM intentions, and episodic future thinking MW for the execution of PM intentions. We discuss the twofold functional role of MW, namely, to consolidate an already programmed intention and to plan future actions.

Cognitive load causes kinematic changes in both elite and non-elite rowers

The current motor literature suggests that extraneous cognitive load may affect performance and kinematics in a primary motor task. A common response to increased cognitive demand, as observed in past studies, might be to reduce movement complexity and revert to previously learned movement patterns, in line with the progression-regression hypothesis. However, according to several accounts of automaticity, motor experts should be able to cope with dual task demands without detriment to their performance and kinematics. To test this, we conducted an experiment asking elite and non-elite rowers to use a rowing ergometer under conditions of varying task load. We employed single-task conditions with low cognitive load (i.e., rowing only) and dual-task conditions with high cognitive load (i.e., rowing and solving arithmetic problems). The results of the cognitive load manipulations were mostly in line with our hypotheses. Overall, participants reduced movement complexity, for example by reverting towards tighter coupling of kinematic events, in their dual-task performance as compared to single-task performance. The between-group kinematic differences were less clear. In contradiction to our hypotheses, we found no significant interaction between skill level and cognitive load, suggesting that the rowers' kinematics were affected by cognitive load irrespective of skill level. Overall, our findings contradict several past findings and automaticity theories, and suggest that attentional resources are required for optimal sports performance.

How to support learning with multimedia instruction: Implementation intentions help even when load is high.

There is ample evidence that multimedia learning is challenging, and learners often underutilize appropriate cognitive processes. Previous research has applied prompts to promote the use of helpful cognitive processing. However, prompts still require learners to regulate their learning, which may interfere with learning, especially in situations where cognitive demands are already high. As an alternative, implementation intentions (i.e. if-then plans) are expected to help regulate behaviour automatically due to their specific wording, thereby offloading demands. Accordingly, this study aimed at investigating whether implementation intentions compared with prompts improve learning performance, especially under high cognitive load. Students (N=120) learned either in a control condition without instructional support, with prompts, or with implementation intentions. Within each condition, half of the participants studied the multimedia instruction under conditions of either high or low cognitive load, which was experimentally manipulated by instructing them to perform one of two secondary tasks. In line with our hypotheses, the results showed that under low cognitive load, both prompts and implementation intentions led to better learning than the control condition. By contrast, under high cognitive load, only implementation intentions promoted learning. Thus, implementation intentions are an efficient means to promote learning even under challenging circumstances.

Passive visual stimulation induces fatigue under conditions of high arousal elicited by auditory tasks.

Theories of cognitive fatigue disagree on whether performance decrement is caused by motivational or functional alterations. Here, drawing inspiration from the habituation and visual adaptation literature, we tested the assumption that keeping neural networks active for an extensive period of time entails consequences at the subjective and objective level-the defining characteristics of fatigue-when confounds such as motivation, boredom, and level of skill are controlled. In Experiment 1, we revealed that passive visual stimulation affected the performance of a subsequent task that was carried out in the same portion of visual space. While under conditions of low cognitive load and arousal, participants improved their performance in the stimulated quadrant; the reverse was observed under high arousal conditions. This latter performance decrement correlated also with the reported subjective level of fatigue and occurred while neural responses to the saturating stimulus remained constant, as assessed through steady-state EEG. In subsequent experiments, we replicated and further characterized this performance deterioration effect, revealing its specificity to the stimulated eye and stimulus orientation. Across the three experiments, the decrease in performance was correlated with pupil-linked arousal, suggesting its mediating effect in this phenomenon. In sum, we show that repeated stimulation of neural networks under high-arousal conditions leads to their altered functional performance, a mechanism which may play a role in the development of global cognitive fatigue. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Evaluation of children's cognitive load in processing and storage of their spatial working memory.

Working memory performance affects children’s learning. This study examined objective (task performance), subjective (self-report), and physiological (pupil dilation) cognitive load (CL) while children completed a spatial working memory complex span task. Frist, 80 Taiwanese 11-year-olds (40 boys) who participated in Experiment 1 confirmed the suitability of the materials. Then, 72 Taiwanese 11-year-olds (35 boys) were assigned to high and low complexity groups to participate in Experiment 2 to test the study hypothesis. Children had to recall at the end of a dual-task list and answer two questions regarding the difficulty and mental effort involved in processing and storage. Their pupil diameters were recorded using an eye-tracker. Two-way mixed ANOVA found that the processing requirements and memory load reduced storage and aggravated the subjective CL of storage; the subjective CL of processing was higher under highly complex conditions. Stepwise regression analysis indicated that subjective CL of processing predicted memory performance in low CL conditions, and physiological CL of processing predicted it in high CL conditions.

Pupil response speed as a marker of cognitive fatigue in early Multiple Sclerosis☆

ContextCognitive fatigue (CF) is a disabling symptom frequently reported by patients with Multiple Sclerosis (pwMS). Whether pwMS in the early disease stages present an increased sensitivity to fatigue induction remains debated. Objective measures of CF have been validated neither for clinical nor research purposes. This study aimed at (i) assessing how fatigue induction by manipulation of cognitive load affects subjective fatigue and behavioural performance in newly diagnosed pwMS and matched healthy controls (HC); and (ii) exploring the relevance of eye metrics to describe CF in pwMS. MethodsNineteen pwMS with disease duration < 5 years and 19 matched HC participated to this study. CF was induced with a dual-task in two separate sessions with varying cognitive load (High and Low cognitive load conditions, HCL and LCL). Accuracy, reaction times (RTs), subjective fatigue and sleepiness states were assessed. Bayesian Analyses of Variance for repeated measures (rmANOVA) explored the effects of time, group and load condition on the assessed variables. Eye metrics (number of long blinks, pupil size and pupil response speed: PRS) were obtained during the CF task for a sub-sample (16 pwMS and 15 HC) and analysed with Generalized Linear Mixed Models (GLMM). ResultsPerformance (accuracy and RTs) was lower in the HCL condition and accuracy decreased over time (BFsincl > 100) while RTs did not significantly vary. Performance over task and conditions followed the same pattern of evolution across groups (BFsincl < 0.08) suggesting that pwMS did not show increased alteration of performance during fatigue induction. Regarding subjective state, both fatigue and sleepiness increased following the task (BFsincl > 15), regardless of condition and group (BFsincl < 3). CF in pwMS seems to be associated with PRS, as PRS decreased during the task amongst pwMS only and especially in the HCL condition (all p < .05). A significant Condition*Group interaction was observed regarding long blinks (p < .0001) as well as an expected effect of cognitive load condition on pupil diameter (p < .01). ConclusionThese results suggest that newly diagnosed pwMS and HC behave similarly during fatigue induction, in terms of both performance decrement and accrued fatigue sensation. Eye metric data further reveal a susceptibility to CF in pwMS, which can be objectively measured.

DLPFC stimulation alters working memory related activations and performance: An interleaved TMS-fMRI study

BackgroundFindings from correlative neuroimaging studies link increased frontoparietal network (FPN) activation and default mode network (DMN) deactivation to enhanced high cognitive demand processing. To causally investigate FPN-DMN contributions to high cognitive demand processing, the current interleaved TMS-fMRI study simultaneously manipulated and indexed neural activity while tracking cognitive performance during high and low cognitive load conditions. MethodsTwenty participants completed an n-back task consisting of four conditions (0-back, 0-backTMS, 2-back, 2-backTMS) while undergoing interleaved TMS-fMRI. During TMS concurrent with n-back blocks, TMS single pulses were delivered to the left DLPFC at 100% motor-threshold every 2.4s. ResultsTMS delivered during high cognitive load strengthened cognitive processing. FPN node activations and DMN node deactivations were increased in the high versus low cognitive load TMS condition. Contrary to our hypothesis, TMS did not increase high load related activation in FPN nodes. However, as hypothesized, increased DMN node deactivations emerged as a function of TMS during high load (right angular gyrus) and from interactions between cognitive load and TMS (right middle temporal gyrus). Load and TMS combined to dampen activation within the DMN at trend level (p = .058). Deactivation in a dorsomedial DMN node was associated with TMS driven improvements in high load cognitive processing. ConclusionsExogenous perturbation of the DLPFC via single pulse TMS amplified DMN node deactivations and enhanced high cognitive demand processing. Neurobehavioral findings linking these effects hint at a promising, albeit preliminary, cognitive control substrate requiring replication in higher-powered studies that use control stimulation.

Acoustic features of voice as a measure of cognitive load during performance of serial subtraction in a remote data collection context

AbstractBackgroundCognitive load is the mental demand a task imposes for a specific person. Performance declines when demand exceed capacity; therefore, increase of mental effort may precede measurable cognitive decline. Physiological indices of load (e.g. heart rate, skin conductance etc.) are sensitive to task demand (e.g. subtracting three vs seven), show increased cognitive load with ageing, and in MCI compared to healthy ageing. Voice features have promise as non‐invasive and scalable indicators of mental effort. Here, we aim to classify serial subtraction at high and low cognitive load using voice recordings captured using an automated remote data collection system.MethodParticipants (aged 17‐86) completed serial subtraction via the Neurovocalix web‐app on their own devices. From a pool of 5,742 participants, 100 were randomly selected for manual review. Seven participants were excluded for audio or performance issues. Responses were transcribed and the start and end of each subtraction attempt marked, producing 3,254 attempts for analysis. Low‐level acoustic features were extracted and aggregated over each attempt, then normalized within participant. Random Forest classifiers were trained and evaluated using Leave‐One‐Subject‐Out‐Cross‐Validation (LOSOCV) to predict high vs low load. LOSOCV repeatedly splits the dataset by subject, with one participant at a time used for testing, and the remainder used for training the model. This produces model predictions for each participant and attempt.ResultAverage cross‐validation accuracy was 0.81 (95% CI 0.78 to 0.84), with an average area under the curve (AUC) of 0.87 (95% CI 0.85 to 0.89). We tested predictions for specific numbers which appeared in both subtraction by seven and by three. Accuracy was 0.78, suggesting that predictions were not driven by specific numeric responses. We observed a significant negative correlation between behavioural performance on the task (response rate), and utterance load probability metric for utterances (ρ=‐0.32, p&lt;0.001), suggesting that participants who were more fluent in serial subtraction exhibited lower cognitive load.ConclusionAcoustic features of voice can distinguish between utterances generated under conditions of high and low cognitive load during serial subtraction, adding a novel, independent and sensitive outcome measure to a cognitive task with established utility in the context of neurodegeneration.

Association Between Cognitive Function and Mechanical Pattern of Landing

Introduction: In examining the factors affecting sports injuries, the emphasis is always on physical variables, while cognitive and psychological characteristics can also be effective. Hence, the present study aimed to investigate the relationship between sustained attention as a neurocognitive function and landing error as a mechanical factor associated with lower limb injuries. Materials and Methods: 44 female basketball players aged 18-25 years at the national league level participated in this study. The participants were assessed using the continuous performance test, and their landing-jumping was evaluated by the landing error scoring system in two conditions of high and low cognitive load. Results: The results showed that people’s landing errors increased significantly as a result of increased cognitive needs (P=0.0001). Also, the findings revealed a positive correlation between omission and commission errors with landing error scores in both low and high cognitive load conditions (P&lt;0.05). Conclusion: Sustained attention could predict the landing error score that is considered a key risk factor of lower limb injuries. It is recommended that multiple cognitive and physical assessments be used to identify athletes at risk of injury. Hence, cognitive enhancement protocols may be effective along with physical preparation programs.

Playing Tetris Lets You Rate Odors as Less Intense.

Overweight and obesity are considered a huge problem in modern societies. Previous studies have shown that people who are regularly distracted by playing videogames or watching TV while eating are more likely to be overweight and that the number of people that are gaming worldwide is rising. Further, it has been established that both, watching TV or playing video games lead to an increased snack intake and a lower rating of perceived taste intensity. Since flavor perception is accomplished not only by the sense of taste but also the sense of smell, we investigated the influence of cognitive load created by playing a video game on odor intensity perception. The participants played a low or high difficulty version of Tetris while presented with odors of food and non-food items. A higher skin conductance response (SCR) along with a decrease in task performance verified that the higher difficulty level leads to a higher cognitive load. Our behavioral data indicates a significant decrease in intensity estimates of food odors and non-food odors during the high compared to low cognitive load condition. We conclude that odor intensity estimation is influenced by real-life cognitive tasks which might in turn lead to overeating while distracted.

Predicting Cognitive Load and Operational Performance in a Simulated Marksmanship Task.

Modern operational environments can place significant demands on a service member's cognitive resources, increasing the risk of errors or mishaps due to overburden. The ability to monitor cognitive burden and associated performance within operational environments is critical to improving mission readiness. As a key step toward a field-ready system, we developed a simulated marksmanship scenario with an embedded working memory task in an immersive virtual reality environment. As participants performed the marksmanship task, they were instructed to remember numbered targets and recall the sequence of those targets at the end of the trial. Low and high cognitive load conditions were defined as the recall of three- and six-digit strings, respectively. Physiological and behavioral signals recorded included speech, heart rate, breathing rate, and body movement. These features were input into a random forest classifier that significantly discriminated between the low- and high-cognitive load conditions (AUC = 0.94). Behavioral features of gait were the most informative, followed by features of speech. We also showed the capability to predict performance on the digit recall (AUC = 0.71) and marksmanship (AUC = 0.58) tasks. The experimental framework can be leveraged in future studies to quantify the interaction of other types of stressors and their impact on operational cognitive and physical performance.

The Neural Signature of Impaired Dual-Tasking in Idiopathic Rapid Eye Movement Sleep Behavior Disorder Patients.

The objective of this cross-sectional study was to determine the neural signature of dual-tasking deficits in idiopathic rapid eye movement sleep behavior disorder using a validated gait paradigm. Fifty-eight participants (28 controls; 30 idiopathic rapid eye movement sleep behavior disorder patients) were recruited; 52 participants had functional MRI scans as they performed a validated dual-task virtual reality gait paradigm using foot pedals. Forty-one participants completed single- and dual-task "overground walking" on a pressure sensor carpet. Idiopathic rapid eye movement sleep behavior disorder patients showed deficits in dual-tasking (i.e., greater mean step time) compared to controls during "overground walking." Functional MRI revealed that idiopathic rapid eye movement sleep behavior disorder patients had reduced blood-oxygen-level-dependent signal change in the dorsal caudate nucleus, and significantly different corticostriatal functional connectivity patterns from controls, when dual-tasking in high versus low cognitive load. While controls showed greater connectivity between frontoparietal and motor networks, idiopathic rapid eye movement sleep behavior disorder patients exhibited less change in this connectivity as a function of cognitive load. These findings demonstrate evidence of dual-task gait deficits in idiopathic rapid eye movement sleep behavior disorder patients, underpinned by disrupted corticostriatal connectivity. Minimal differences in the level of functional connectivity between dual-tasking conditions of high and low cognitive load suggest that idiopathic rapid eye movement sleep behavior disorder patients recruit cognitive networks to control gait even when the cognitive demands are low. This may indicate a compensatory strategy for early cognitive decline in idiopathic rapid eye movement sleep behavior disorder. © 2020 International Parkinson and Movement Disorder Society.

Novel methodology for assessing total recovery time in response to unexpected perturbations while walking.

Walking stability is achieved by adjusting the medio-lateral and anterior-posterior dimensions of the base of support (step length and step width, respectively) to contain an extrapolated center of mass. We aimed to calculate total recovery time after different types of perturbations during walking, and use it to compare young and older adults following different types of perturbations. Walking trials were performed in 12 young (age 26.92 ± 3.40 years) and 12 older (age 66.83 ± 1.60 years) adults. Perturbations were introduced at different phases of the gait cycle, on both legs and in anterior-posterior or medio-lateral directions, in random order. A novel algorithm was developed to determine total recovery time values for regaining stable step length and step width parameters following the different perturbations, and compared between the two participant groups under low and high cognitive load conditions, using principal component analysis (PCA). We analyzed 829 perturbations each for step length and step width. The algorithm successfully estimated total recovery time in 91.07% of the runs. PCA and statistical comparisons showed significant differences in step length and step width recovery times between anterior-posterior and medio-lateral perturbations, but no age-related differences. Initial analyses demonstrated the feasibility of comparisons based on total recovery time calculated using our algorithm.

The Effects of Cognitive Load on Craving Triggered by Food Cues in External Eaters

This study examined the effects of cognitive load on attentional bias toward food cues in external eaters (EEs) through an eye-movement analysis. As EEs are easily driven to eat upon exposure to food cues, the present study examined the effects of cognitive load on the response toward food cues in EEs based on the elaborated intrusion theory. A total of 65 undergraduates who have high (n=33) or low (n=32) levels of external eating were assigned to either high or low cognitive load conditions and performed a cognitive load task. While they performed the load task, their implicit craving was measured with an eye-tracking device to examine the levels of attentional bias toward food cues during the task. After the task was completed, explicit craving was investigated through a questionnaire. The results showed that high EEs under a high cognitive load condition showed lower implicit craving than under a low load condition while their explicit craving did not differ. This study suggests that cognitive load that induces cognitive distraction may lower implicit craving in high EEs.

Effects of personality traits on user trust in human–machine collaborations

Data analytics-driven solutions are widely used in various intelligent systems, where humans and machines make decisions collaboratively based on predictions. Human factors such as personality and trust have significant effects on such human–machine collaborations. This paper investigates effects of personality traits on user trust in human–machine collaborations under uncertainty and cognitive load conditions. A user study of 42 subjects in a repeated factorial design experiment found that uncertainty presentation led to increased trust but only under low cognitive load conditions when users had sufficient cognitive resources to process the information. Presentation of uncertainty under high load conditions led to a decrease in trust. When further drilling down into personality trait groups of users, overall, users with low Openness showed the highest trust. Furthermore, under the low cognitive load condition, it was found that the trust was enhanced under ambiguity uncertainty with low Agreeableness, low Neuroticism, high Extraversion, high Conscientiousness, and high Openness. Under the high cognitive load condition, high Neuroticism and low Extraversion benefitted the trust without the uncertainty presentation. The results demonstrated that different personality traits affected trust differently under uncertainty and cognitive load conditions. A framework of user trust feedback loop was set up to incorporate the study results into human–machine collaborations for the meaningful participatory design.

Neural mechanisms underlying state mental fatigue in multiple sclerosis: a pilot study.

Neuroimaging underpinnings of state (in the moment, transient) mental fatigue in multiple sclerosis (MS) are not well understood. The current pilot study examined the effect of state mental fatigue on brain activation (measured using functional magnetic resonance imaging [fMRI]) during conditions of varying cognitive loads of rapid information processing in persons with MS relative to healthy controls. Nineteen persons with MS and 17 healthy controls underwent fMRI scanning while performing a modified version of the Symbol Digit Modalities Test, which consisted of high and low cognitive load conditions with comparable visual stimulation. State mental fatigue was assessed using the Visual Analog Scale of Fatigue before and after each run of the behavioral task. Results indicated that the healthy control group recruited significantly more anterior brain regions (superior and middle frontal gyri, insula, and superior temporal gyrus) to meet increased task demands during the high cognitive load condition as fatigue level increased (p < 0.05), which was accompanied by shorter response time. In contrast, the MS group did not recruit anterior areas to the same extent as the healthy control group as task demands and fatigue increased. Indeed, the MS group continued to activate more posterior brain regions (precuneus, lingual gyrus, and middle occipital gyrus) for the high cognitive load condition (p < 0.05) with no improvement in speed. In conclusion, persons with MS may allocate neural resources less efficiently than healthy controls when faced with increased task demands, which may result in increased mental fatigue. Results of the current pilot investigation warrant replication with a larger sample size.