Subjective Ratings Of Difficulty Research Articles

The Aha! experience is associated with a drop in the perceived difficulty of the problem.

The study investigated the correlation between the intensity of the Aha! experience and participants' subjective difficulty ratings of problems before and after finding their solutions. We assumed that the Aha! experience arises from a shift in processing fluency triggered by changing from an initially incoherent problem representation to a coherent one, which ultimately leads to the retrieval of a solution with unexpected ease and speed. First, we hypothesized that higher Aha! experience ratings would indicate more sudden solutions, manifesting in a reduced correlation between the initial difficulty ratings and solution times. Second, we hypothesized that higher Aha! experience ratings would correspond to a greater shift in the subjective difficulty ratings between the initial and retrospective assessments. To test our hypotheses, we developed a novel set of rebus puzzles. A total of 160 participants solved rebuses and provided initial (within 5 s of problem presentation) and retrospective difficulty ratings (following the generation or presentation of a correct solution). They also rated their Aha! experience (after solution generation or presentation), confidence in solutions, and the likability of each rebus. Our findings revealed that the initial ratings of the problem's subjective difficulty were positively correlated with the solution time and that this correlation decreased in the case of a stronger Aha! experience. Aha! experience ratings were positively correlated with the differences between initial and retrospective difficulty ratings, confidence, solution accuracy, and rebus likability. We interpreted our results to be in line with the processing fluency and metacognitive prediction error accounts.

Difficulty limits of visual mental imagery

While past work has focused on the representational format of mental imagery, and the similarities of its operation and neural substrate to online perception, surprisingly little has tested the boundaries of the level of detail that mental imagery can generate. To answer this question, we take inspiration from the visual short-term memory literature, a related field which has found that memory capacity is affected by the number of items, whether they are unique, and whether and how they move. We test these factors of set size, color heterogeneity, and transformation in mental imagery through both subjective (Exp 1; Exp 2) and objective (Exp 2) measures – difficulty ratings and a change detection task, respectively – to determine the capacity limits of our mental imagery, and find that limits on mental imagery are similar to those for visual short-term memory. In Experiment 1, participants rated the difficulty of imagining 1–4 colored items as subjectively more difficult when there were more items, when the items had unique colors instead of an identical color, and when they scaled or rotated instead of merely linearly translating. Experiment 2 isolated these subjective difficulty ratings of rotation for uniquely colored items, and added a rotation distance manipulation (10° to 110°), again finding higher subjective difficulty for more items, and for when those items rotated farther; the objective measure showed a decrease in performance for more items, but not for rotational degree. Congruities between the subjective and objective results suggest similar costs, but some incongruities suggest that subjective reports can be overly optimistic, likely because they are biased by an illusion of detail.

Metacognitive Awareness of Difficulty in Action Selection: The Role of the Cingulo-opercular Network.

The question whether and how we are able to monitor our own cognitive states (metacognition) has been a matter of debate for decades. Do we have direct access to our cognitive processes, or can we only infer them indirectly based on their consequences? In the current study, we wanted to investigate the brain circuits that underlie the metacognitive experience of fluency in action selection. To manipulate action-selection fluency, we used a subliminal response priming paradigm. On each trial, both male and female human participants additionally engaged in the metacognitive process of rating how hard they felt it was to respond to the target stimulus. Despite having no conscious awareness of the prime, results showed that participants rated incompatible trials (during which subliminal primes interfered with the required response) to be more difficult than compatible trials (where primes facilitated the required response), reflecting metacognitive awareness of difficulty. This increased sense of subjective difficulty was mirrored by increased activity in the rostral cingulate zone and the anterior insula, two regions that are functionally closely connected. Importantly, this reflected activations that were unique to subjective difficulty ratings and were not explained by RTs or prime-response compatibility. We interpret these findings in light of a possible grounding of the metacognitive judgment of fluency in action selection in interoceptive signals resulting from increased effort.

The Variability Effect: When Instructional Variability Is Advantageous

Based on cognitive load theory, this paper reports on two experiments investigating the variability effect that occurs when learners’ exposure to highly variable tasks results in superior test performance. It was hypothesised that the effect was more likely to occur using high rather than low levels of guidance and testing more knowledgeable than less knowledgeable learners. Experiment 1, which tested 103 adults studying pre-university mathematics, showed no interaction between levels of variability (high vs. low) and levels of instructional guidance (worked examples vs. unguided problem solving). The significant main effect of variability indicated a variability effect regardless of levels of instructional guidance. Experiment 2, which tested another group of 56 adults enrolled in the same mathematics program, showed an interaction between levels of variability (high vs. low) and levels of learner expertise (novices vs. experts). More experienced learners learned more from high rather than low variability tasks demonstrating the variability effect, while less experienced learners learned more from low rather than high variability tasks demonstrating a reverse variability effect. It was suggested that more experienced learners had sufficient available working memory capacity to process high variability information while less experienced learners were overwhelmed by high variability and learned more using low variability information. Subjective ratings of difficulty supported the assumptions based on cognitive load theory. The major educational implication is that learners should initially be presented with low variability or easier tasks, and as they gain more experience in the task domain, variability or task difficulty should increase.

Electroencephalographic Correlates of Continuous Postural Tasks of Increasing Difficulty

Cortical involvement in postural control is well recognized, however the role of non-visual afferents remains unclear. Parietal cortical areas are strongly implicated in vestibulo-spatial functions, but topographical localization during balance tasks remains limited. Here, we use electroencephalography (EEG) during continuous balance tasks of increasing difficulty at single electrode positions. Twenty-four healthy, right-handed individuals performed four balance tasks of increasing difficulty (bipedal and unipedal) and a seated control condition with eyes closed. Subjective ratings of task difficulty were obtained. EEG was recorded from 32 electrodes; 5 overlying sensory and motor regions of interest (ROIs) were chosen for further investigation: C3, Cz, C4, P3, P4. Spectral power and coherence during balance tasks were analyzed in theta (4–8 Hz) and alpha (8–12 Hz) bands. Alpha power reduced as task difficulty increased and this reduction correlated with subjective difficulty ratings. Alpha coherence increased with task difficulty between C3–Cz–C4 electrode pairs. Differential changes in power were observed in Cz, suggestive of a distinct role at this electrode location, which captures lower limb cortical representation. Hemispheric asymmetry was observed, as reflected by greater reductions in theta and alpha power in right-sided areas. Our results demonstrate the functional importance of bilateral central and parietal cortices in continuous balance control. The hemispheric asymmetry observed implies that the non-dominant hemisphere is involved with online monitoring of postural control. Although the posterior parietal asymmetry found may relate to vestibular, somatosensory or multisensory feedback processing, we argue that the finding relates to active balance control rather than simple sensory-intake or reflex circuit activation.

Modeling study of seated reach envelopes based on spherical harmonics with consideration of the difficulty ratings

Reach envelopes are very useful for the design and layout of controls. In building reach envelopes, one of the key problems is to represent the reach limits accurately and conveniently. Spherical harmonics are proved to be accurate and convenient method for fitting of the reach capability envelopes. However, extensive study are required on what components of spherical harmonics are needed in fitting the envelope surfaces. For applications in the vehicle industry, an inevitable issue is to construct reach limit surfaces with consideration of the seating positions of the drivers, and it is desirable to use population envelopes rather than individual envelopes. However, it is relatively inconvenient to acquire reach envelopes via a test considering the seating positions of the drivers. In addition, the acquired envelopes are usually unsuitable for use with other vehicle models because they are dependent on the current cab packaging parameters. Therefore, it is of great significance to construct reach envelopes for real vehicle conditions based on individual capability data considering seating positions. Moreover, traditional reach envelopes provide little information regarding the assessment of reach difficulty. The application of reach envelopes will improve design quality by providing difficulty-rating information about reach operations. In this paper, using the laboratory data of seated reach with consideration of the subjective difficulty ratings, the method of modeling reach envelopes is studied based on spherical harmonics. The surface fitting using spherical harmonics is conducted for circumstances both with and without seat adjustments. For use with adjustable seat, the seating position model is introduced to re-locate the test data. The surface fitting is conducted for both population and individual reach envelopes, as well as for boundary envelopes. Comparison of the envelopes of adjustable seat and the SAE J287 control reach envelope shows that the latter is nearly at the middle difficulty level. It is also found that the abilities of reach envelope models in expressing the shape of the reach limits based on spherical harmonics depends both on the terms in the model expression and on the data used to fit the envelope surfaces.

Effects of systemic complexity factors on task difficulty in a stock management game

In an experimental research involving stock management, we test the effects of three complexity factors on game performance measure and perceived difficulty ratings, first individually at different factor levels, and then in interaction with each other. Experiments show that, with respect to the base game, only the delay factor causes worsening in player performance, with increased delay duration and delay order. Nonlinearity and feedback do not deteriorate game performance by themselves, but they become mildly significant when they exist together with delay. Players’ subjective difficulty ratings also indicate strong delay effect, and no other significant factor. Game scores and subjective difficulty ratings are positively correlated (0.58). Our results show that each complexity factor has a different type and level of influence on the overall task difficulty, which has implications for designing better simulators for education and training. Copyright © 2015 System Dynamics Society

Pictionary-based fMRI paradigm to study the neural correlates of spontaneous improvisation and figural creativity.

A novel game-like and creativity-conducive fMRI paradigm is developed to assess the neural correlates of spontaneous improvisation and figural creativity in healthy adults. Participants were engaged in the word-guessing game of PictionaryTM, using an MR-safe drawing tablet and no explicit instructions to be “creative”. Using the primary contrast of drawing a given word versus drawing a control word (zigzag), we observed increased engagement of cerebellum, thalamus, left parietal cortex, right superior frontal, left prefrontal and paracingulate/cingulate regions, such that activation in the cingulate and left prefrontal cortices negatively influenced task performance. Further, using parametric fMRI analysis, increasing subjective difficulty ratings for drawing the word engaged higher activations in the left pre-frontal cortices, whereas higher expert-rated creative content in the drawings was associated with increased engagement of bilateral cerebellum. Altogether, our data suggest that cerebral-cerebellar interaction underlying implicit processing of mental representations has a facilitative effect on spontaneous improvisation and figural creativity.

The Influence of Drinking, Texting, and Eating on Simulated Driving Performance

Objective: Driving is a complex task and distractions such as using a mobile phone for the purpose of text messaging are known to have a significant impact on driving. Eating and drinking are common forms of distraction that have received less attention in relation to their impact on driving. The aim of this study was to further explore and compare the effects of a variety of distraction tasks (i.e., text messaging, eating, drinking) on simulated driving.Methods: Twenty-eight healthy individuals (13 female) participated in a crossover design study involving 3 experimental trials (separated by ≥24 h). In each trial, participants completed a baseline driving task (no distraction) before completing a second driving task involving one of 3 different distraction tasks (drinking 400 mL water, drinking 400 mL water and eating a 6-inch Subway sandwich, drinking 400 mL water and composing 3 text messages). Primary outcome measures of driving consisted of standard deviation of lateral position (SDLP) and reaction time to auditory and visual critical events. Subjective ratings of difficulty in performing the driving tasks were also collected at the end of the study to determine perceptions of distraction difficulty on driving.Results: Driving tasks involving texting and eating were associated with significant impairment in driving performance measures for SDLP compared to baseline driving (46.0 ± 0.08 vs. 41.3 ± 0.06 cm and 44.8 ± 0.10 vs. 41.6 ± 0.07 cm, respectively), number of lane departures compared to baseline driving (10.9 ± 7.8 vs. 7.6 ± 7.1 and 9.4 ± 7.5 vs. 7.1 ± 7.0, respectively), and auditory reaction time compared to baseline driving (922 ± 95 vs. 889 ± 104 ms and 933 ± 101 vs. 901 ± 103 ms, respectively). No difference in SDLP (42.7 ± 0.08 vs. 42.5 ± 0.07 cm), number of lane departures (7.6 ± 7.7 vs. 7.0 ± 6.8), or auditory reaction time (891 ± 98 and 885 ± 89 ms) was observed in the drive involving the drink-only condition compared to the corresponding baseline drive. No difference in reaction time to visual stimuli was observed between baseline and experimental drives for any of the trial conditions. Participants’ subjective ratings indicated that they perceived the texting while driving condition to be the most difficult despite similar magnitudes of impairment observed with the eating while driving condition.Conclusions: Distracting behaviors such as eating and texting while driving appear to negatively impact driving measures of lane position control and reaction time. These findings may have direct implications for motorists that engage in these types of distracting behaviors behind the wheel and for the safety of other road users.

Effects of Stimulating Hip and Trunk Muscles on Seated Stability, Posture, and Reach After Spinal Cord Injury

ObjectiveTo determine the stimulated strength of the paralyzed gluteal and paraspinal muscles and their effects on the seated function of individuals with paralysis. DesignCase series with subjects acting as their own concurrent controls. SettingHospital-based clinical biomechanics laboratory. ParticipantsUsers (N=8) of implanted neuroprostheses for lower extremity function with low-cervical or thoracic level injuries. InterventionsDynamometry and digital motion capture both with and without stimulation to the hip and trunk muscles. Main Outcome MeasuresIsometric trunk extension moment at 0°, 15°, and 30° of flexion; seated stability in terms of simulated isokinetic rowing; pelvic tilt, shoulder height, loaded and unloaded bimanual reaching to different heights, and subjective ratings of difficulty during unsupported sitting. ResultsStimulation produced significant increases in mean trunk extension moment (9.2±9.5Nm, P<.001) and rowing force (27.4±23.1N, P<.012) over baseline volitional values. Similarly, stimulation induced positive changes in average pelvic tilt (16.7±15.7°) and shoulder height (2.2±2.5cm) during quiet sitting and bimanual reaching, and increased mean reach distance (5.5±6.6cm) over all subjects, target heights, and loading conditions. Subjects consistently rated tasks with stimulation easier than voluntary effort alone. ConclusionsIn spite of considerable intersubject variability, stabilizing the paralyzed trunk with electrical stimulation can positively impact seated posture, extend forward reach, and allow exertion of larger forces on objects in the environment.

The impact of personal protective equipment and breathing apparatus on offshore lifeboat evacuation time

A primary objective of this study was to determine if the 15 minutes of air contained in an emergency breathing apparatus afforded sufficient time to carry out an evacuation from an offshore installation in the event of an uncontrolled hydrogen sulfide (H2S) release. Twenty-four male and 12 female volunteers performed relevant evacuation skills during a simulated evacuation into a 36-person lifeboat. An observational analysis and subjective ratings of difficulty were used to determine potential ergonomic and safety issues. Results indicate that even under the worst-case scenario, all personnel would be able to safely evacuate to the lifeboat and abandon the installation given similar conditions used during this study. It was noted however, that ergonomic improvements to the design of the personal protective and safety equipment could improve usability, thus decrease abandonment times.

Subjective Ratings of Accessibility Using Full-Scale Bathroom Environments

Full-scale modeling was used to assess subjective ratings of difficulty for the bathroom environment across four different configurations. Two configurations complied with nationally accepted accessibility standards. One exceeded the standards, representing a “universal design”; the other was representative of a common yet unsupportive design. Participants simulated activities of daily living and offered subjective ratings of each design in general, and for each sub-area (e.g. toilet, shower, lavatory) for each design. Results demonstrate subjective differences between bathroom configurations. The interaction between humans and the built environment should include a host of diagnostic tools complete with subjective assessments.

Effects of wearing chemical protective clothing on text entry when using wearable input devices

Wearable computers allow users the freedom to work in any environment including those that may require protective clothing. Past research has shown that protective clothing impedes performance on manual dexterity tasks. Little information exists; however, regarding how protective clothing affects task performance with wearable input devices. A study was conducted to determine the effects of glove thickness and mask use on task performance and user preference. Sixteen male participants used both a wearable mouse and touch pad to enter text. Task completion times were 9% slower when participants wore 25-mil versus 7-mil protective gloves, suggesting that thin protective gloves are more suitable than thicker gloves when using wearable input devices. Mask use did not affect task performance. Subjective ratings of difficulty, confidence, and preference provided strong support for the use of a touch pad device rather than a mouse. Potential applications of this research include design guidelines for development of wearable input devices that are compatible with chemical protective clothing. Relevance to industry Protective clothing is commonly worn in industrial settings, but little is known about its impacts on task performance with wearable computers. This study describes some of the factors that must be considered in the design of wearable input devices that can be used effectively when wearing protective clothing.

Conceptual combination in schizophrenia: Contrasting property and relational interpretations

This study employed a conceptual combination task based on Estes and Glucksberg [(2000). Interactive property attribution in concept combination. Memory & Cognition, 28(1), 28–34] to address the question of whether semantic processing abnormalities in schizophrenia arise from deficits in semantic storage or access, or the controlled use of semantic memory representations. High thought disorder schizophrenia patients ( n = 25 ), low thought disorder schizophrenia patients ( n = 22 ), and controls ( n = 25 ) read and interpreted noun–noun combinations that varied with respect to whether the modifier noun had a salient semantic feature that could be mapped to a relevant dimension of a head noun. The percentages of property attributions, relational interpretations, and “other” interpretations were determined for each combination type. Subjective difficulty ratings were also collected for each response. Neither high nor low thought disorder patients differed from controls in the production of property interpretations. High thought disorder patients were significantly less likely to generate relational interpretations and significantly more likely to generate “other” interpretations. Subjective difficulty ratings were low for all groups, suggesting that differences in the ease of generating interpretations does not account for the results. The finding of intact property interpretations suggests that the integrity and initial access of semantic memory is spared in schizophrenia. In contrast, the reduced production of relational interpretations and increased production of “other” interpretations in schizophrenia suggests a compromised ability to engage in the controlled processing operations necessary to make flexible use of semantic material.

Effects of Chemical Protective Clothing on Task Performance Using Wearable Input Devices

Wearable computers allow users the freedom to work in any environment including those that may require protective clothing. Past research has shown that protective clothing impedes performance on manual dexterity tasks. Little information exists, however, regarding how protective clothing affects task performance with wearable input devices. To facilitate future development of wearable input devices, a study was conducted to determine the effects of glove thickness and respirator use on task performance and user preference. Sixteen male participants used both a wearable mouse and touch pad to enter text. Task completion times were 9% slower when participants wore 25-mil versus 7-mil protective gloves, suggesting that thin protective gloves (i.e. 7-mil and 14-mil) are more suitable than thicker gloves when using wearable input devices. Respirator use did not affect task performance. Subjective ratings of difficulty, confidence, and preference provided strong support for the use of a touch pad device rather than a mouse.

RATINGS OF DIFFICULTY OR PAIN MAY BE BETTER INDICATORS OF FUNCTIONAL DEFICITS THAN LEVEL OF ASSISTANCE IN PATIENTS RECOVERING FROM CORONARY ARTERY BYPASS

Rationale: Activities of daily living (ADL) performance is an important but infrequently evaluated aspect of function in patients recovering from coronary artery bypass (CAB). Self-report assessments of function are often used and are typically based on the amount of assistance required for ADL. Objectives: The purpose of this study was to determine if ratings of difficulty or pain were more likely to detect deficits in ADL performance than the level of assistance. Methodology: This study included 53 patients who had recently undergone CAB. We evaluated ADL performance using 3 subcategories of the Functional Status Index (FSI), mobility, personal care, and hand activities. Under each subcategory of the FSI, subjects rated their level of assistance, difficulty, and pain with activities on a 5-point scale. Subjects completed the FSI 2 weeks and again 2 months following CAB. We used Wilcoxon Signed Ranks Test to compare differences in scores rating assistance to those of difficulty and pain (P <.05). Results: Scores rating difficulty were lower for all FSI subcategories than scores rating assistance except personal care at 2 months and hand activities at 2 weeks. Perceived difficulty with ADL performance was reported 15-55% more often than need for assistance with ADL. Scores rating pain were lower for all FSI subcategories except hand activities at 2 weeks. ADL limitations due to pain were reported 16-51% more often that need for assistance with ADL. Conclusion: Subjective ratings of difficulty and pain may be more sensitive than level of assistance when evaluating ADL ability in patients recovering from CAB. In this patient population, assessments of functional ability that rely only on level of assistance may underestimate the presence of functional deficits.

Dissociable Contributions of the Human Amygdala and Orbitofrontal Cortex to Incentive Motivation and Goal Selection

Theories of incentive motivation attempt to capture the way in which objects and events in the world can acquire high motivational value and drive behavior, even in the absence of a clear biological need. In addition, for an individual to select the most appropriate goal, the incentive values of competing desirable objects need to be defined and compared. The present study examined the neural substrates by which appetitive incentive value influences prospective goal selection, using positron emission tomographic neuroimaging in humans. Sated subjects were shown a series of restaurant menus that varied in incentive value, specifically tailored for each individual, and in half the trials, were asked to make a selection from the menu. The amygdala was activated by high-incentive menus regardless of whether a choice was required. Indeed, activity in this region varied as a function of individual subjective ratings of incentive value. In contrast, distinct regions of the orbitofrontal cortex were recruited both during incentive judgments and goal selection. Activity in the medial orbital cortex showed a greater response to high-incentive menus and when making a choice, with the latter activity also correlating with subjective ratings of difficulty. Lateral orbitofrontal activity was observed selectively when participants had to suppress responses to alternative desirable items to select their most preferred. Taken together, these data highlight the differential contribution of the amygdala and regions within the orbitofrontal cortex in a neural system underlying the selection of goals based on the prospective incentive value of stimuli, over and above homeostatic influences.

Effects of characteristics of image quality in an immersive environment.

Image quality issues such as field of view (FOV) and resolution are important for evaluating "presence" and simulator sickness (SS) in virtual environments (VEs). This research examined effects on postural stability of varying FOV, image resolution, and scene content in an immersive visual display. Two different scenes (a photograph of a fountain and a simple radial pattern) at two different resolutions were tested using six FOVs (30, 60, 90, 120, 150, and 180 deg.). Both postural stability, recorded by force plates, and subjective difficulty ratings varied as a function of FOV, scene content, and image resolution. Subjects exhibited more balance disturbance and reported more difficulty in maintaining posture in the wide-FOV, high-resolution, and natural scene conditions.

Effects of a target movement direction cue on head-tracking performance

A review of the literature has shown that most investigations of head-tracking performance have used symmetrically shaped targets. This paper identifies a problem in using circular targets to represent the movement of complex targets (i.e. targets giving directional cues). Two experiments investigated the effects of a target direction cue on head-tracking performance. In the first experiment, practice did not improve performance when tracking either with or without a ‘look-ahead trace’ showing all target positions 160 ms into the future. A second experiment utilized a ‘look-ahead trace’ showing target positions with eight different lead-times (0-560 ms). With lead-times of 160 ms or more, significant improvements in tracking performance and subjective difficulty ratings were obtained. Tracking responses were also significantly affected. The results suggest caution when performance data obtained with a symmetrical target are generalized to predict tracking performance with a real target giving cues to the direction of movement. The look-ahead trace offers a systematic means of bridging the gap between a symmetrical target and a real target having direction of movement cues.

Micromodel for Objective Estimation of Driver Mental Workload from Task Data

Observation of driver performance during a 58 000-km (36,000-mile) field study of van pooling indicates that a good estimate of mental workload can be made from an analysis of objective performance data alone. Drivers traversed a mix of rural secondary roads, limited-access expressways, high-density, limited-access urban drives, and downtown city streets on a daily commute from upstate New York to New York City. Data included road characteristics, time, traffic density, speed, weather, brake applications, subsidiary task performance, and subjective difficulty ratings. Driving workload had two components, a steady-state load dictated by road conditions, speed, and traffic density and a transient load determined by the degree of uncertainty in the driving situation. Brake actuations represent the uncertainty inherent in driving while the log2 of the speed is a first approximation of the steady-state information processing load imposed by tracking requirements of vehicle control. Unpredictability of traffic appeared to be the major determinant of perceived difficulty. Workload homeostasis occurred as drivers modified their performance to keep workload within a comfortable range. An objective workload index of the general form, workload = f (brake actuation rate + log2 speed) based on this micromodel of driver behavior predicts subjective driving difficulty. An analysis of variance shows that the workload index distinguished between road types at the p &lt; .0001 level of significance. The workload index correlates at r = .74, 18(df), with the subjective driving degrees of freedom difficulty ratings and at r = .81, 18 df, with the mental workload estimates of the best subsidiary task.