Cognitive Load Assessment Research Articles

Putting Theory to Practice: Applying Cognitive Load Theory to Resident Medical Education.

We built 2 versions of an asynchronous pediatric orthopedic educational intervention for emergency medicine residents and sought to compare the two. We hypothesized that the version incorporating more instructional scaffolding in the form of a cognitive aid (CA) would optimize germane cognitive load for our target novice learners and result in higher test scores. Learners were block randomized to either a "CA" or "non-CA" arm, each containing a random set of 18 modules. The CA arm incorporated an orthopedic fracture classification chart embedded within the diagnostic questions to guide the learner in forming a diagnosis. The non-CA arm was designed with more active learning as the classification chart was provided only after each diagnostic answer submission. For both arms, the final 6 modules completed per learner were scored. Learners also completed a perceived cognitive load assessment tool measured on a 10-point Likert scale. Learners in the non-CA arm had a mean total score on the testing modules of 33% correct compared with a mean total score of 44% correct for learners in the CA arm (mean difference, 11; 95% confidence interval, 4%-19%, P = 0.005). There was a trend for the CA arm to have lower perceived overall cognitive load scores; however, this did not reach statistical significance. Emergency medicine residents performed better after completing the CA version of our educational intervention. Applying cognitive load theory to an educational intervention may increase its success among target learners.

Assessment of cognitive load using pupillometric measures in neuro-typical population: Application in forensic sciences

Assessment of cognitive load using pupillometric measures in neuro-typical population: Application in forensic sciences

Cognitive and Affective Assessment of Navigation and Mobility Tasks for the Visually Impaired via Electroencephalography and Behavioral Signals.

This paper presented the assessment of cognitive load (as an effective real-time index of task difficulty) and the level of brain activation during an experiment in which eight visually impaired subjects performed two types of tasks while using the white cane and the Sound of Vision assistive device with three types of sensory input—audio, haptic, and multimodal (audio and haptic simultaneously). The first task was to identify object properties and the second to navigate and avoid obstacles in both the virtual environment and real-world settings. The results showed that the haptic stimuli were less intuitive than the audio ones and that the navigation with the Sound of Vision device increased cognitive load and working memory. Visual cortex asymmetry was lower in the case of multimodal stimulation than in the case of separate stimulation (audio or haptic). There was no correlation between visual cortical activity and the number of collisions during navigation, regardless of the type of navigation or sensory input. The visual cortex was activated when using the device, but only for the late-blind users. For all the subjects, the navigation with the Sound of Vision device induced a low negative valence, in contrast with the white cane navigation.

Beyond traditional approaches: a partial directed coherence with graph theory-based mental load assessment using EEG modality

Brain connectivity-based methods are efficient and reliable for assessing the mental workload during high task demands as the human brain is functionally interconnected during any psychological task. On the other hand, the graph theory approach is a mathematical study that draws the pairwise relationships between objects. This paper covers the deployment of graph theory concepts on the brain connectivity methods to find the complex underlying behaviors of the brain in the simplest way. Furthermore, in this work, mental workload assessments on multimedia animations were performed using a brain connectivity approach based on partial directed coherence (PDC) with graph theory analysis. Electroencephalography (EEG) data were collected from 34 adult participants at baseline and during multimedia learning tasks. The results revealed that the EEG-based connectivity approach with graph theory offers more promising results than the traditional feature extraction techniques. The connectivity approach achieved an accuracy of 85.77% in comparison with the 78.50% accuracy achieved by the existing feature extraction techniques. It is concluded that the proposed PDC method with graph theory network analysis is a better solution for cognitive load assessment during any cognitive task.

Assessing cognitive load in adolescent and adult students using photoplethysmogram morphometrics.

Compared to cardiac parameters and skin conductivities, the photoplethysmogram (PPG) recorded at fingertips and other parts near to peripheral nerve ends have been recently revealed to be yet another sensitive measure for cognitive load assessment. However, there is so far no research on measuring adolescents' cognitive load using physiological signals. A comprehensive study on the effects of PPG morphometrics over a cohort covering both adolescent and adult students is also absent. In this study, we analyze the morphological features of PPG on cognitive load assessment and compare them between adolescent and adult students. Experiments on two-level arithmetic tasks show that the PPG morphometrics reached the same level of significance on the effect of task difficulty/period as heart rate, and different morphological behaviors were also shown between adolescent and adult students during the cognitive task effects, which may imply their physiological differences across age. Physiological signals recorded by wearable devices are also found to be effective in measuring cognitive load.

Effect of virtual annotation on performance of construction equipment teleoperation under adverse visual conditions

Construction equipment teleoperation is a promising solution when the site environment is hazardous to operators. However, limited situational awareness of the operator, especially under adverse visual conditions, impedes the implementation of construction equipment teleoperation. Virtual annotations (VAs) have great potential to improve an operator's situational awareness. The work presented in this paper investigates the effects of VA by comparing the teleoperation performances of an excavator between an experimental group (with VA) and a control group (without VA) in a virtual environment. Subjects in the experimental group made significantly fewer collisions under the adverse visual condition than the subjects in the control group with similar 3D gaming experience. It indicates that properly-designed VAs can help operators efficiently integrate and understand information from different visual sources. Some negative effects were also observed, such as increased time of completion and a trend of increased collision numbers on the back of the equipment. Speculation is that an operator will form a visual base and selectively integrate information from other visual sources when the cognitive load exceeds a limit. The results suggested a need to investigate further the mechanism of forming a visual base and the assessment of an operator's cognitive load.

The impact of task load on the integration of explicit contextual priors and visual information during anticipation.

There is limited knowledge about the impact of task load on experts' integration of contextual priors and visual information during dynamic and rapidly evolving anticipation tasks. We examined how experts integrate contextual priors--specifically, prior information regarding an opponent's action tendencies--with visual information such as movement kinematics, during a soccer-specific anticipation task. Furthermore, we combined psychophysiological measures and retrospective self-reports to gain insight into the cognitive load associated with this integration. Players were required to predict the action of an oncoming opponent, with and without the explicit provision of contextual priors, under two different task loads. In addition to anticipation performance, we compared continuous electroencephalography (EEG) and self-reports of cognitive load across conditions. Our data provide tentative evidence that increased task load may impair performance by disrupting the integration of contextual priors and visual information. EEG data suggest that cognitive load may increase when contextual priors are explicitly provided, whereas self-report data suggested a decrease in cognitive load. The findings provide insight into the processing demands associated with integration of contextual priors and visual information during dynamic anticipation tasks, and have implications for the utility of priors under cognitively demanding conditions. Furthermore, our findings add to the existing literature, suggesting that continuous EEG may be a more valid measure than retrospective self-reports for in-task assessment of cognitive load.

A cognitive load assessment study of three-dimensional interactive virtual reality interfaces

A cognitive load assessment study of three-dimensional interactive virtual reality interfaces

Photoplethysmogram-based Cognitive Load Assessment Using Multi-Feature Fusion Model

Cognitive load assessment is crucial for user studies and human--computer interaction designs. As a noninvasive and easy-to-use category of measures, current photoplethysmogram- (PPG) based assessment methods rely on single or small-scale predefined features to recognize responses induced by people’s cognitive load, which are not stable in assessment accuracy. In this study, we propose a machine-learning method by using 46 kinds of PPG features together to improve the measurement accuracy for cognitive load. We test the method on 16 participants through the classical n-back tasks (0-back, 1-back, and 2-back). The accuracy of the machine-learning method in differentiating different levels of cognitive loads induced by task difficulties can reach 100% in 0-back vs. 2-back tasks, which outperformed the traditional HRV-based and single-PPG-feature-based methods by 12--55%. When using “leave-one-participant-out” subject-independent cross validation, 87.5% binary classification accuracy was reached, which is at the state-of-the-art level. The proposed method can also support real-time cognitive load assessment by beat-to-beat classifications with better performance than the traditional single-feature-based real-time evaluation method.

An observational study using eye tracking to assess resident and senior anesthetists' situation awareness and visual perception in postpartum hemorrhage high fidelity simulation.

BackgroundThe postpartum hemorrhage (PPH) is the leading cause of maternal mortality in the world. Human factors and especially situation awareness has primarily responsibility to explain suboptimal cares. Based on eye tracking and behavior analysis in high fidelity simulation of PPH management, the goal of this study is to identify perceptual and cognitive key parameters of the expertise.MethodsTwo groups of fifteen anesthetists (residents and experienced anesthetists) watched the beginning of a severe simulated PPH management. During this first experimental phase, situation awareness was assessed using SAGAT (Situation Awareness Global Assessment Technique) questionnaire and visual behavior was analyzed with eye tracking. In the continuity of the video sequence, they have to step in the PPH situation and to provide care to the simulated patient. Performance of cares was evaluated and self-assessed as well as cognitive load.ResultsNo statistical difference between the residents and experienced anesthetists was observed on performance of simulated PPH management. The mean expected practice score was 76.9 ± 13.9%). Assessment of situation awareness (65 ± 7%), cognitive load (74.4 ± 11.3%) and theoretical knowledge of PPH (52.4 ± 3.5%) were also not statistically different between the two groups. Only results of self-assessed performance (respectively 66.1 ± 16.6 and 47.0 ± 20.8 for experts and residents) and eye-tracking data revealed that experts tended to get accurate evaluation of their performance and to monitor more the blood loss of the patient. Experts have in average 8.28% more fixating points than Novices and gazed the blood loss region longer (865 ms ± 439 vs. 717 ms ± 362).ConclusionsThis study pointed out the limits of classical assessment of performance, and human factors based on questionnaires to identify expertise in simulated PPH care. A neuroscientific approach with new technology like eye tracking could provide new objective and more sensitive insights on human factors in simulated medical emergency situations.

High Cognitive Load Assessment in Drivers Through Wireless Electroencephalography and the Validation of a Modified N-Back Task

This paper explores the influence of high cognitive load on vehicle driver's electroencephalography (EEG) signals collected from two channels (Fp1, Fp2) using a wireless consumer-grade system. Although EEG has been used in driving-related research to assess cognitive load, only a few studies focused on high load, and they used research-grade systems. Recent advancements allow for less intrusive and more affordable systems. As an exploration, we tested the feasibility of one such system to differentiate among three levels of cognitive taskload in a simulator study. Thirty-seven participants completed a baseline drive with no secondary task and two drives with a modified version of the n-back task (1-back and 2-back). The modification removed the verbal response required during task presentation to prevent EEG-signal degradation, with the 2-back task expected to impose higher load than that by the 1-back task. Another objective of this study is to validate that this modified task increased the cognitive load in the expected manner. The modified task led to significant trends from baseline to 1-back, and from 1-back to 2-back in participants' heart rate, galvanic skin response, respiration, horizontal gaze position variability, and pupil diameter, all in line with the previous driving-related studies on cognitive load. Furthermore, the EEG system was observed to be sensitive to the modified task, with the power of alpha band decreasing significantly with increasing n-back levels (baseline versus 1-back: 0.092 Bels on Fp1, 0.179 on Fp2; 1-back versus 2-back: 0.209 on Fp1, 0.147 on Fp2). Thus, a consumer-grade EEG system has the potential to capture high levels of cognitive load experienced by drivers.

Comparison of 3- vs 2-Dimensional Endoscopy Using Eye Tracking and Assessment of Cognitive Load Among Surgeons Performing Endoscopic Ear Surgery

Endoscopic ear surgery (EES) is an emerging technique to treat middle ear diseases; however, the interventions are performed in 2-dimensional (2D) endoscopic views, which do not provide depth perception. Recent technical developments now allow the application of 3-dimensional (3D) endoscopy in EES. To investigate the usability, advantages, and disadvantages of 3D vs 2D endoscopy in EES under standardized conditions. This cohort study conducted at a tertiary academic medical center in Bern, Switzerland, included 16 residents and consultants of the Department of Otorhinolaryngology, Head & Neck Surgery, Inselspital, Bern. Each participant performed selected steps of a type I tympanoplasty and stapedotomy in 3D and 2D views in a cadaveric model using a randomized, Latin-square crossover design. Time taken to perform the EES, number of attempts, and accidental damage during the dissections were compared between 3D and 2D endoscopy. Eye tracking was performed throughout the interventions. Cognitive load and subjective feedback were measured by standardized questionnaires. Of the 16 surgeons included in the study (11 inexperienced residents; 5 experienced consultants), 8 were women (50%); mean age was 36 years (range, 27-57 years). Assessment of surgical time revealed similar operating times for both techniques (181 seconds in 2D vs 174 seconds in 3D). A total of 64 surgical interventions were performed. Most surgeons preferred the 3D technique (10 for 3D vs 6 for 2D), even though a higher incidence of eye strain, measured on a 7-point Likert scale, was observed (3D, 2.19 points vs 2D, 1.44 points; mean difference , 0.74; 95% CI, 0.29-1.20; r = 0.67). Eye movement assessment revealed a higher duration of fixation for consultants in 2D (0.79 seconds) compared with 3D endoscopy (0.54 seconds), indicating a less-efficient application of previously acquired experiences using the new technique. Residents (mean [SD], 49.02 [16.4]) had a significantly higher workload than consultants (mean [SD], 27.21 [12.20]), independent of the used technique or task. Three-dimensional endoscopy is suitable for EES, especially for inexperienced surgeons whose mental model of the intervention has yet to be consolidated. The application of 3D endoscopy in clinical routines and for educational purposes may be feasible and beneficial.

Effect of Mental Workload on Breathing Pattern and Heart Rate for a Working Memory Task: A Pilot Study.

Mental workload or cognitive load is the total amount of mental resources required while doing a task. Apart from qualitative measures, various physiological signals are being used for assessment of mental workload. However, very limited research has been done on assessment of cognitive load from respiratory signals. In the present study, we have tried to analyze the cognitive load mainly based on respiratory features. n-back memory test has been modified to impart low and high cognitive load. The peripheral blood volume signal (PPG) collected while executing the task is used to reconstruct the breathing pattern signal. A number of morphological as well as statistical features are calculated from this reconstructed signal. Finally a classifier is used for classifying the low and high cognitive load. Results show that a classification accuracy of 76.8% is obtained while using respiratory features only. A maximum accuracy of 81.80% is obtained if we combine time domain PPG features with respiratory features. The features finally selected can also be used to study the habituation effect.

Hemodynamic Analysis for Cognitive Load Assessment and Classification in Motor Learning Tasks Using Type-2 Fuzzy Sets

This paper addresses a novel approach to assess and classify the cognitive load of subjects from their hemodynamic response while engaged in motor learning tasks, such as vehicle driving. A set of complex motor-activity-learning stimuli for braking, steering-control, and acceleration is prepared to experimentally measure and classify the cognitive load of the car drivers in three distinct classes: high, medium, and low. New models of general and interval type-2 fuzzy classifiers are proposed to reduce the scope of uncertainty in cognitive load classification due to the fluctuation of the hemodynamic features within and across sessions. The proposed classifiers offer high classification accuracy over 96%, leaving behind the traditional type-1/type-2 fuzzy and other standard classifiers. Experiments undertaken also offer a deep biological insight concerning the shift of brain activations from the orbitofrontal to the ventrolateral prefrontal cortex during the high-to-low transition in cognitive load. Furthermore, the activation of the dorsolateral prefrontal cortex is also reduced during the low cognitive load of subjects. The proposed research work outcome may directly be utilized to identify driving learners with a low cognitive load for difficult motor learning tasks, such as taking a U-turn in a narrow space and motion control on the top of a bridge to avoid possible collision with the car ahead.

On the development of a method for cognitive load assessment in manufacturing

The increasing complexity and demands of assembly operations in manufacturing has been shown to lead to increased cognitive load in assembly workers. Previous work has outlined the complexity of an ...

A Cognitive load assessment study of Three-dimensional Interactive Virtual Reality Interfaces

Advances in virtual reality (VR) open possibilities for novel three-dimensional (3D) graphical user interfaces (GUIs) to emerge for complex tasks and information visualisation. However, three dimen...

Estimating cognitive load from speech gathered in a complex real-life training exercise

Abstract Speech-enabled applications are becoming prevalent, providing opportunities for real-time detection of speaker characteristics. Estimation of cognitive load from speech is one type of speaker characteristic that can provide insight into the human state in complex, highly dynamic human-machine teaming scenarios and be used to adapt interaction with the user to their current cognitive state. Cognitive load estimation from speech experiments are typically performed on speech gathered in laboratory settings. By contrast, this research is performed on a real-life dataset that was not created for the purpose of cognitive load assessment. Speech was extracted from recordings of a military simulation exercise in which air battle managers communicated with pilots flying simulated aircraft. This paper assesses whether cognitive load can be estimated from speech self-labelled by exercise participants and collected in a realistic setting, and examines how well cognitive load estimation methods translate from the laboratory setting to the real-world. Analysis suggests that participants’ self-assessment of workload at periodic intervals can be used to label speech to create 2-class cognitive load classifiers. The analysis also shows that including some target speaker speech in speaker independent training data results in higher classification accuracy than when classifiers are built solely from speaker dependent data.

Schema-related cognitive load influences performance, speech, and physiology in a dual-task setting: A continuous multi-measure approach

Schema acquisition processes comprise an essential source of cognitive demands in learning situations. To shed light on related mechanisms and influencing factors, this study applied a continuous multi-measure approach for cognitive load assessment. In a dual-task setting, a sample of 123 student participants learned visually presented symbol combinations with one of two levels of complexity while memorizing auditorily presented number sequences. Learners’ cognitive load during the learning task was addressed by secondary task performance, prosodic speech parameters (pauses, articulation rate), and physiological markers (heart rate, skin conductance response). While results revealed increasing primary and secondary task performance over the trials, decreases in speech and physiological parameters indicated a reduction in the overall level of cognitive load with task progression. In addition, the robustness of the acquired schemata was confirmed by a transfer task that required participants to apply the obtained symbol combinations. Taken together, the observed pattern of evidence supports the idea of a logarithmically decreasing progression of cognitive load with increasing schema acquisition, and further hints on robust and stable transfer performance, even under enhanced transfer demands. Finally, theoretical and practical consequences consider evidence on desirable difficulties in learning as well as the potential of multimodal cognitive load detection in learning applications.

Cognitive load of walking in people who are blind: Subjective and objective measures for assessment

BackgroundAlthough walking without vision seems to carry a high cognitive cost, few studies have measured the cognitive load involved in this activity in blind people. The aim of this study was to assess the cognitive load of walking in blind people, using gait analysis, a dual task paradigm and a subjective assessment of cognitive load. MethodsIn a quantitative quasi-experimental design, 25 blind adults walked 40 meters. In one trial, participants walked normally (control condition). In another, they walked while performing an auditory simple reaction time task, and in the third trial they walked, performed the simple reaction time task and avoided obstacles. In addition to the simple reaction time task performance, walking speed was recorded, and participants provided a subjective assessment of cognitive load after each trial. Performance of participants aged less than 60 years were compared with those aged over than 60 years. ResultsWalking significantly reduced performance of the simple reaction time task; carrying out the simple reaction time task while walking significantly reduced walking performance and increased the subjective assessment of cognitive load; and simple reaction time task performance decreased and subjective assessment increased when obstacles were present. Few significant age effects were found. SignificanceWalking without vision involves a cognitive load that increases when the environment becomes complex. Each of the three methods used is relevant when assessing the cognitive load involved in walking in blind people, and could be useful in rehabilitation intervention. The results obtained allowed recommendations to be suggested for the design of technological mobility devices.

Evaluating Photoplethysmogram as a Real-Time Cognitive Load Assessment during Game Playing

ABSTRACTAccurate evaluation for user experience during computer game playing is very important in optimizing game design to improve the gaming experience. When evaluating user experiences, the concept of cognitive load is crucial for dynamically responding to game players’ mental status. In our former studies, the photoplethysmogram (PPG)-based Stress-Induced Vascular Response Index (sVRI) shows better sensitivity and reliability in measuring cognitive loads compared with heart-rate variation, blood pressure, and galvanic skin response. In this study, we use memory matrixes and Pop Cap’s tower defense game Plants vs. Zombies as cognitive tasks and use sVRI to assess players’ cognitive load dynamically during the real-time computer games. Evaluations on cognitive tasks verified the usability of sVRI in comparison with other indexes derived from PPG, such as heartbeat interval, area under curve, digital pulse amplitude, reflection index, and inflection point area ratio. Our findings indicate the potential of sVRI for assessing game players’ mental workload in real time.