Proprioception Variables as Determinants of Lapsed Time Estimation∗

Abstract

It was postulated that increasing positional and force cues would provide more discriminable stimuli to serve as references for the reproduction of a motor response. The levels and mode of the proprioceptive feedback were varied during the coincident positioning task of moving a carriage along a trackway in 2·0 sec. In a balanced design with 80 Ss, 2 values of positional cues, moving the carriage over 2·5 or 65·0 cm, and 2 values of force cues, minimal resistance and 18·9 kg, produced 4 different feedback combinations. Significant learning occurred during 30 trials with knowledge of results (KB), and the combinations involving movement produced the greatest accuracy. Throughout 30 trials without knowledge of results (NoKR) the estimates produced by the movement only and weight only groups became longer, whilst the control group and the movement plus weight group did not drift. It was suggested that the group differences were caused by fatigue.

Interpolated rests of 1 min between groups of 5 trials during the KB condition shortened the first post-rest trial whence performance was restored by the remaining 4 trials. During NoKB the first post-rest trial was again shorter, but since the remaining 4 were overestimated it was more accurate.

In view of these results, apparently redundant movements might aid in timing tasks requiring temporal and spatial organization.     

The role of peripheral vision in vertical road sign identification and discrimination

Abstract

The role of peripheral vision in road sign identification and discrimination was investigated in two studies. Peripheral vision plays an important role in road signs perception due to their lateral positioning. In the first study 20 participants identified road signs presented at five levels of horizontal eccentricity (1.1°–12.4°), and two levels of vertical eccentricity (0°–2.5°). In the second study road sign discrimination was tested in a same-different discrimination task. The first study showed that a vertical offset of 2.5° degraded proportion correct rate by 9%. Proportion correct rate decreased from 79% to 41% in the transition from 1.1° to 12.4° of horizontal offset. The second study showed an accurate discrimination for road signs presented within a horizontal offset of 6.4°. Road signs with angular shapes and prominent vertexes as triangular or cross signs were better identified in peripheral vision than signs with more compact shapes (circular signs).

Practitioner summary: Vertical road signs, due to their lateral positioning, are often perceived in peripheral vision. Horizontal and vertical eccentricity negatively impacts the driver’s ability to correctly identify and discriminate traffic signs. The use of singular shapes and a design with simple pictograms and large contrasting areas strongly facilitate road sign perception in peripheral vision.     

MULTIPLE CHANNEL MONITORING

This experiment investigated the effect of channel load in a one-, two- and three-meter vigilance task. Also investigated was the effect of training under one of the three-channel load conditions when subjects were later transferred to a two-channel condition. Subjects monitored a voltmeter display for 64 minutes.

Results showed that the overall performance of the two- and three-channel groups was virtually identical, and considerably inferior to the single-channel group in the initial session. A time decrement was exhibited by all three groups. In the second session when all subjects monitored two channels, no significant differences between groups wore found.

The results are discussed in terms of time-sharing load on the monitor, and implications for equipment design and training.     

The use of contextual cues to improve warning symbol comprehension: making the connection for older adults

This study teased apart the effects of comprehensibility and complexity on older adults' comprehension of warning symbols by manipulating the relevance of additional information in further refining the meaning of the symbol. Symbols were systematically altered such that increased visual complexity (in the form of contextual cues) resulted in increased comprehensibility. One hundred older adults, aged 50–71 years, were tested on their comprehension of these symbols before and after training. High comprehensibility–complexity symbols were found to be better understood than low- or medium-comprehensibility–complexity symbols and the effectiveness of the contextual cues varied as a function of training. Therefore, the nature of additional detail determines whether increased complexity is detrimental or beneficial to older adults' comprehension – if the additional details provide ‘cues to knowledge’, older adults' comprehension improves as a result of the increased complexity. However, some cues may require training in order to be effective.

Practitioner Summary: Research suggests that older adults have greater difficulty in understanding more complex symbols. However, we found that when the complexity of symbols was increased through the addition of contextual cues, older adults' comprehension actually improved. Contextual cues aid older adults in making the connection between the symbol and its referent.     

Noise Exposure,Monitoring and Tracking Performance as a Function of Signal Bias and Task Priority

Abstract

An experiment was conducted to extend some findings reported by Hockey (1970 a, b) who employed a primary tracking and secondary watchkeeping task. He found that when signals were more probable in the centre and subjects were asked to perform a central tracking task, they missed peripheral signals while in noise. When signals were equally probable at all loci this effect did not occur. Hockey concluded that the effect reflects a funnelling of attention rather than of vision. In the present experiment similar tracking and watchkeeping tasks were employed, but for separate groups either the watchkeeping or tracking was primary and the other task secondary. In the primary tracking group there was a subgroup for which signal probability was higher in the centre and one in which there was no bias; for the primary watchkeeping group there was a subgroup for which signal probability was higher in the periphery and a subgroup for which there was no bias. In each subgroup there were 12 subjects, who performed the tasks on different days under three Noise Conditions (75 dBA background noise, 136 dB (SPL) peak periodic impulse noise, and 105 dBA recorded continuous noise). Results quite different from those reported by Hockey were obtained: there was no effect of noise on quality of monitoring, but tracking performance was impaired. Possible explanations are advanced.     

SENSITIZING SOCIAL AGENTS FOR VIRTUAL TRAINING

ABSTRACT

Virtual training allows the learning and rehearsal of implicit cues, e.g., trustworthy leading action in an emergency evacuation, that cannot be easily understood through merely reading about situations, while mitigating the danger and expense of live rehearsals. We have focused our efforts on designing social agents that can engage in and help to train humans to generate the trustworthy behaviors that help to ensure a successful evacuation. Drawing upon social science research and using a “role-reversal method,” we successfully constructed agents that can perceive trustworthiness as humans do. The agents first collect human responses to their own nonverbal cues in controlled experimental training scenarios. Using these results, we obtain optimal parameters for nonverbal cues of trustworthiness, and then can use them to guide agents who evaluate human performance in the same training scenarios. The method enables us to convert social psychological findings into computational mechanisms.     

Effects of feedback type and modality on motor skill learning and retention

ABSTRACT

Two types of feedback, including knowledge of results (KR) and knowledge of performance (KP) are typically delivered as part of motor training using different sensory modalities. Twenty-four right-handed individuals performed a computer-based psychomotor training task using a contemporary haptic interface. Results revealed that KP was superior to KR for overall task performance retention, whereas KR was good for training specific aspects of performance. A combination of KP and KR through the same modality did not produce an additive positive learning effect for task performance. Auditory and haptic feedback improved retention over visual, but only with the use of multiple information cues. Design guidelines are provided for training systems for motor skill development and/or rehabilitation.     

Effectiveness of auditory and tactile crossmodal cues in a dual-task visual and auditory scenario

Abstract

In this study, we examined how spatially informative auditory and tactile cues affected participants’ performance on a visual search task while they simultaneously performed a secondary auditory task. Visual search task performance was assessed via reaction time and accuracy. Tactile and auditory cues provided the approximate location of the visual target within the search display. The inclusion of tactile and auditory cues improved performance in comparison to the no-cue baseline conditions. In comparison to the no-cue conditions, both tactile and auditory cues resulted in faster response times in the visual search only (single task) and visual–auditory (dual-task) conditions. However, the effectiveness of auditory and tactile cueing for visual task accuracy was shown to be dependent on task-type condition. Crossmodal cueing remains a viable strategy for improving task performance without increasing attentional load within a singular sensory modality.

Practitioner Summary: Crossmodal cueing with dual-task performance has not been widely explored, yet has practical applications. We examined the effects of auditory and tactile crossmodal cues on visual search performance, with and without a secondary auditory task. Tactile cues aided visual search accuracy when also engaged in a secondary auditory task, whereas auditory cues did not.     

Comparison of swimming with running as training stimuli

Abstract

The cardiovascular training effect was compared between swimming and running. Twenty-two healthy young adult women trained for 6 weeks either swimming or running with the same frequency,.duration and intensity (as judged by heart rate). Both groups showed significant improvement in cardiovascular fitness after training, assessed on a bicycle ergometer, with no significant difference between the two groups before or after training.     

The training of knowledge structures for manufacturing tasks: an empirical study

Abstract

Knowledge structure refers to the manner in which a human organizes knowledge with a given domain. Research has identified knowledge structure as a determinant of the human ability to perform cognitive-oriented tasks. Yet uncertainty still exists about how to improve an individual's cognitive task performance through the controlled utilization of the individual's knowledge structure. The purpose of this study is to investigate whether the development of individual's knowledge structure in a particular domain can be manipulated through training. The experiment utilized the manufacturing domain of plastic extrusion machine operation. Sixteen subjects, having no previous knowledge of the domain, were randomly assigned to one of two experimental groups. Each of the experimental groups corresponded to a distinct training condition. Over a three-day period, both training groups received the same instructional content; however, the sequence in which the training material was presented differed. One group initially received the abstract, conceptual relationships between domain concepts, followed by more detailed relationships associated with the lower level aspects of the domain. The other group received the training material in the reverse order; i.e. the lower level information followed by the abstract. Prior to and concluding the training sessions, each individual's knowledge structure was assessed along two dimensions, hierarchical levels and multiple relations, through a computer-based measurement technique.entitled KSAT. The group which received the abstract relationships first showed significant improvement following training along both dimensions of knowledge structure. No significant changes in the knowledge structure dimensions were found for the group which received the lower level relationships first. This study suggests that an individual's knowledge structure can be manipulated through training, with a significant effect being attributed to the training sequence of abstract material followed by the more detailed material.     

Real-Time Active SLAM and Obstacle Avoidance for an Autonomous Robot Based on Stereo Vision

Abstract

In this article, the problem of real-time robot exploration and map building (active SLAM) is considered. A single stereo vision camera is exploited by a fully autonomous robot to navigate, localize itself, define its surroundings, and avoid any possible obstacle in the aim of maximizing the mapped region following the optimal route. A modified version of the so-called cognitive-based adaptive optimization algorithm is introduced for the robot to successfully complete its tasks in real time and avoid any local minima entrapment. The method’s effectiveness and performance were tested under various simulation environments as well as real unknown areas with the use of properly equipped robots.     

Efficient collection and automatic annotation of real-world object images by taking advantage of post-diminished multiple visual markers*

ABSTRACT

To collect a human-annotated dataset for training deep convolutional neural networks is a very time-consuming and laborious process. To reduce this burden, we previously proposed an automated annotation by placing one visual marker above the detection target object in the training phase. However, in this approach, occasionally the marker hides the object surface. To avoid this issue, we propose placing a pedestal with multiple markers at the bottom of the object. If we use multiple markers, the object can be annotated even when the object hides some of the markers. Besides that, the simple modification of placing the markers on the bottom allows the use of simple background masking to avoid the neural network learning the remaining markers in the training image as a feature of the object. Background masking can completely remove the markers during the training process. Experiments showed the proposed vision system using our automatic object annotation outperformed the vision system using manual annotation in terms of object detection, orientation estimation, and 2D position estimation while reducing the time required for dataset collection from 16.1 hours to 7.30 hours.     

Effects of Heat Stress on Performance

Abstract

Three groups of subjects, seven subjects each, were required, to perform a central tracking task and simultaneously respond to peripheral stimuli, while being exposed to heat stress environments. One group was exposed to a 95°F and 50% RH environment, the second group was exposed to a 95°F and 75% RH environment, and the third group was exposed to a 100°F and 50% RH environment.

The performance results showed that there was a significant deterioration in tracking and increase in reaction time only when the subjects were exposed to the 95°F and 75% RH environment. The peripheral field of awareness was not significantly affected by any of the three environments.     

Interaction Unit Analysis: A New Interaction Design Framework

ABSTRACT

A pragmatic approach to interaction modeling is presented by which a designer can describe how the user gets tasks done with a newly developing system. The notation proposed allows an interaction designer to make explicit both how user actions cause visible or noticeable changes in the state of the machine and how the user is expected to use this feedback to generate the next action. Interaction Unit (IU) scenarios are constructed where each IU specifies one step in the cycle of interaction. Each IU specifies the visible system state that leads the user to take some action. In addition, the IU makes explicit the state of the goal stack at the start and end of the unit and the mental processes (recall, recognition, or affordance) required. In this way one can describe the intimate connection between goal, action, and the environment in user–machine interaction.

To demonstrate the completeness of IU scenario analysis, IU models are presented for some well-known problems in interaction design: hidden and partially hidden modes leading to unexpected system effects, insufficient cues for subgoal construction, insufficient cues for subgoal elimination, and inappropriate affordances for action. These scenarios are accompanied by procedures that designers can use to detect similar problems in putative interaction designs.

To demonstrate the feasibility of using IU scenario analysis in design, 4 graduate students were taught to use IU scenario analysis in a 3-hr session. They then worked as a group to evaluate a prototype handheld warehouse application. A comparable group was taught and then applied Cognitive Walkthrough. Both groups successfully completed the task and detected several problems rated as being of high severity by the designers of the prototype. Analysis of the problems detected by each group suggests that the two techniques are complimentary. IU scenario analysis may be most cost-effective for devices using new interaction paradigms, whereas Cognitive Walkthrough may be most cost-effective for designs using established interaction paradigms.     

Effect of physical workload and modality of information presentation on pattern recognition and navigation task performance by high-fit young males

Abstract

Many occupations require both physical exertion and cognitive task performance. Knowledge of any interaction between physical demands and modalities of cognitive task information presentation can provide a basis for optimising performance. This study examined the effect of physical exertion and modality of information presentation on pattern recognition and navigation-related information processing. Results indicated males of equivalent high fitness, between the ages of 18 and 34, rely more on visual cues vs auditory or haptic for pattern recognition when exertion level is high. We found that navigation response time was shorter under low and medium exertion levels as compared to high intensity. Navigation accuracy was lower under high level exertion compared to medium and low levels. In general, findings indicated that use of the haptic modality for cognitive task cueing decreased accuracy in pattern recognition responses.

Practitioner Summary: An examination was conducted on the effect of physical exertion and information presentation modality in pattern recognition and navigation. In occupations requiring information presentation to workers, who are simultaneously performing a physical task, the visual modality appears most effective under high level exertion while haptic cueing degrades performance.     

Digital enhancement of television signals for people with visual impairments: Evaluation of a consumer product

Abstract— Technology to improve the clarity of video for home‐theater viewers is available utilizing a low‐cost enhancement chip (DigiVision DV1000). The impact of such a device on the preference for enhanced video was tested for people with impaired vision and normally sighted viewers. Viewers with impaired vision preferred the enhancement effects more than normally sighted viewers. Preference for enhancement was correlated with loss in contrast sensitivity and visual acuity. Preference increased with increased enhancement settings (designed for those with normal vision) in the group with vision impairments. This suggests that higher enhancement levels may be of even greater benefit, and a similar product could be designed to meet the needs of the large, growing population of elderly television viewers with impaired vision.     

A Note on the Role of Peripheral Vision in Static Balancing

The ability to balance statically using minimal visual cues was investigated experimentally. It was found that sighted levels of proficiency wore not consistently achiovod in tho absence of background structure.     

Effects of sign characteristics and training methods on safety sign training effectiveness

This study investigated whether or not training methods affected the effectiveness of symbol training and if there were any relationships between sign symbol characteristics and training effectiveness. Altogether, 26 Mainland China industrial safety signs were used and 60 participants were randomly assigned into four equal-sized groups of control, paired-associate learning, recall training and recognition training. The result was that participants from all the training groups showed significantly greater improvement in comprehension performance than those in the control group, indicating that the training methods improved comprehension of the meaning of safety signs. Participants from the recall training group performed better in the post-training test than those from other training groups. It seems that the recall task elicited a deeper level of learning than the recognition task and that questioning and feedback had a positive effect on training effectiveness. The results also showed that sign characteristics had no significant influence on training effectiveness. It was concluded that recall training is more effective in enhancing comprehension of industrial safety signs than paired-associate learning or recognition training. The findings of this study provide a basis for useful guidelines for designing symbol-training programmes and for designing more user-friendly safety signs.

Statement of Relevance: The present study shows that recall training was more effective in improving comprehension of industrial safety signs than paired-associate learning or recognition training and cognitive sign features did not influence training effectiveness. They provide a basis for useful guidelines for designing symbol-training programmes and for designing more user-friendly safety signs.     

Visual interference with users’ tasks on multiwindow systems

This study investigated the potential visual interference imposed by displayed peripheral windows that are not central to a user's current task performance. In particular, the study examined the relation between foveal vision and peripheral vision activities in multiwindow systems. It was suggested that the number and layout of the windows in a multiwindow system can interfere with a user's activities while performing a task. Results from a visual search experiment were indicated as follows:

1. Displayed peripheral windows interfered with a user's current task performance.

2. The number of the peripheral windows is a significant factor in the interference.

3. The types of the layout, overlapping or nonoverlapping, are also a significant factor in the interference.

4. The activities of the foveal vision get worse when the visual position of the task performance is closer to the peripheral windows.

5. These factors have different influences depending on whether the peripheral windows are static or dynamic

We discuss these results from the viewpoint of the nature of the human visual systems, especially the relation between foveal and peripheral vision.     

Training for the job: evaluation of a self-defence training programme for correctional officers

Abstract

We investigated to what extent correctional officers were able to apply skills from their self-defence training in reality-based scenarios. Performance of nine self-defence skills were tested in different scenarios at three moments: before starting the self-defence training programme (Pre-test), halfway through (Post-test 1), and after (Post-test 2). Repeated measures analyses showed that performance on skills improved after the self-defence training. For each skill, however, there was a considerable number of correctional officers (range 4–73%) that showed insufficient performance on Post-test 2, indicating that after training they were not able to properly apply their skills in reality-based scenarios. Reality-based scenarios may be used to achieve fidelity in assessment of self-defence skills of correctional officers.

Practitioner summary: Self-defence training for correctional officers must be representative for the work field. By including reality-based scenarios in assessment, this study determined that correctional officers were not able to properly apply their learned skills in realistic contexts. Reality-based scenarios seem fit to detect discrepancies between training and the work field.

Abbreviations: DJI: Dutch National Agency for Correctional Insitutes; ICC: Intraclass Correlation Coefficient