Comprehensibility of Newly Introduced Water-sport Prohibitive Signs in Korea by Koreans and Westerners

Objective: The goal of this study is to evaluate the comprehensibility of the newly introduced water-sport prohibitive signs by the Ministry of Knowledge Economy (MKE, later merged into the Ministry of Trade, Industry and Energy) among Koreans and westerners, and to check whether the comprehensibility is affected by cultural differences. Background: The Ministry of Knowledge Economy had newly introduced fourteen water-sport prohibitive signs at the end of 2011 to alert people to potentially dangerous situations. However, no studies had been found so far to review or assess their comprehensibility. Method: Comprehensibility tests of fourteen water-sport prohibitive signs were conducted with forty Koreans and forty Westerners in two sequential sessions. In session I, participants were asked to guess the meaning of each sign verbally in an open-ended test. In session II, participants were encouraged to provide feedback for each sign after its intended meaning was given. Results: Only two out of fourteen signs satisfied the comprehension rate (67%) recommended by ISO standard for both groups (Koreans and Westerners). Cultural difference between Koreans and westerners significantly affect the comprehension rates of the investigated signs, and Westerners exhibit better overall comprehension than Koreans. Five poorly comprehended signs for both Korean and Western groups were identified. Conclusion: The recently introduced water-sport prohibitive warning signs by MKE still need a lot of improvements in order to be implemented nationally or internationally. There were significant differences in the signs' comprehensibility between Koreans and westerners. Application: The findings may serve as a useful input for researchers and watersport sign designers in creating easy-to-comprehend safety signs.clos

Action Monitoring in One-Dimensional Force Production

An important mechanism that is essential to avoid error and is possessed by human beings is the ability to monitor one’s own cognitive functioning, often referred to as ‘action monitoring’. Force production is one example from numerous real life situations which requires precise and continuous action monitoring, in which an irreversible false decision during its execution could lead to highly dangerous situations. Despite its importance, most of the studies in the area of action monitoring investigated tasks with discrete response parameters (i.e., left or right hand responses during flanker task), leaving action monitoring during continuous tasks like force production insufficiently investigated. The general aim of the present research was to learn more about the response dynamics during a simple one-dimensional force production task so that the monitoring processes involved in the brain during the task execution could be better understood. Therefore, two studies were conducted. The first study (N = 48) investigated how force execution of a simple one-dimensional force production task unfolds. The results from this study indicated that magnitude and timing of the force pulse (i.e., the response force parameters) were defined by the motor program even before response execution. As a force pulse is a ballistic process, an early definition of the response parameters seems to be an efficient monitoring strategy, as it allows for a fast force production and could provide information for error detection process. However, the process of determining these response parameters seemed to precede the process of determining the correctness of the response itself. The second study (N = 40) incorporated a modified Psychological Refractory Period (PRP) paradigm using two consecutive simple force production tasks, to investigate if force monitoring process during these two subsequent force tasks was modulated by different Response-Stimulus Intervals. This study showed successful replication of a PRP effect in an adapted force paradigm. On a behavioral level, PRP effect seemed to modulate not only Response Time, but also the response force parameters such as Peak Force and Time-to-Peak Force. Furthermore, PRP effect also seemed to modulate the neural correlates of force monitoring. Finally, three alternative models were postulated to elucidate how the different Response-Stimulus Interval affected the information processing stages of two subsequent simple one-dimensional force tasks. Taken together, findings from the second study could serve as an evidence that PRP effect is present in subsequent simple force production tasks, without the necessity of motor overlap between the first and the second task

Neural correlates of error detection during complex response selection: Introduction of a novel eight-alternative response task

Error processing in complex decision tasks should be more difficult compared to a simple and commonly used two-choice task. We developed an eight-alternative response task (BART), which allowed us to investigate different aspects of error detection. We analysed event-related potentials (ERP; N = 30). Interestingly, the response time moderated several findings. For example, only for fast responses, we observed the well-known effect of larger error negativity (N-e) in signalled and non-signalled errors compared to correct responses, but not for slow responses. We identified at least two different error sources due to post-experimental reports and certainty ratings: impulsive (fast) errors and (slow) memory errors. Interestingly, the participants were able to perform the task and to identify both, impulsive and memory errors successfully. Preliminary evidence indicated that early (N-e-related) error processing was not sensitive to memory errors but to impulsive errors, whereas the error positivity seemed to be sensitive to both error types

Eye movements and brain oscillations to symbolic safety signs with different comprehensibility

Background: The aim of this study was to investigate eye movements and brain oscillations to symbolic safety signs with different comprehensibility. Methods: Forty-two young adults participated in this study, and ten traffic symbols consisting of easy-to-comprehend and hard-to-comprehend signs were used as stimuli. During the sign comprehension test, real-time eye movements and spontaneous brain activity [electroencephalogram (EEG) data] were simultaneously recorded. Results: The comprehensibility level of symbolic traffic signs significantly affects eye movements and EEG spectral power. The harder to comprehend the sign is, the slower the blink rate, the larger the pupil diameter, and the longer the time to first fixation. Noticeable differences on EEG spectral power between easy-to-comprehend and hard-to-comprehend signs are observed in the prefrontal and visual cortex of the human brain. Conclusions: Sign comprehensibility has significant effects on real-time nonintrusive eye movements and brain oscillations. These findings demonstrate the potential to integrate physiological measures from eye movements and brain oscillations with existing evaluation methods in assessing the comprehensibility of symbolic safety signs.open

Assessment of Warning Comprehensibility Utilizing Subjective and Physiological Measures

Department of Human and Systems EngineeringAccidents are multi-causal and can be caused by one or more factors such as human errors, machine failures, inadequate safety information, etc. Despite the fact that human errors cannot be completely prevented, various attempts had been made to minimize the likeliness of human errors, one of which is the utilization of safety signs. Consequently, it is important for safety signs to be well designed and comprehended correctly for them to be able to convey warning messages to their prospective users. Faulty safety sign design could lead to increased potential risks in public places. This thesis was aimed to propose a comprehensive approach in safety sign evaluation by integrating physiological measures and nontraditional subjective measures that have not been used in previous safety sign evaluation studies, in addition to the existing subjective evaluation methods such as guessability score and cognitive sign features. The secondary objective of this thesis was to investigate the effect of cultural differences in safety sign comprehension. In addition, this study also investigated the utilization of users??? feedback and ergonomic design principles in safety sign redesign attempt. In total, 100 participants (forty Westerners and sixty Koreans) participated in the first major experiment which was focused on investigating cultural difference effects during safety sign comprehension. A set of newly introduced water-sport safety signs was used in this study. In addition, a redesign attempt was done on the poorly comprehended signs by utilizing participants??? feedback from both groups, while taking into account ergonomic principles of good design. The second major experiment was aimed to fill the existing gaps in traditional safety sign evaluating methods, by investigating physiological measures (heart rate, eye tracking measures, EEG signal) and nontraditional subjective measurements (perceived cognitive load and compliance to ergonomic design principles) which were hypothesized to reflect cognitive load elicited by a safety sign. A total of forty two Koreans participated in this study, and two sets of frequently used safety signs (traffic signs and healthcare symbols) were used as stimuli. The first experiment results suggested that people who come from different cultural origins may have different perception and understanding regarding a set of safety signs. Therefore, findings from our first study justified the importance of designing multi-culturally compatible safety signs. Considering ergonomic design principles as well as participants??? feedback was also proven to be noteworthy in safety sign redesign attempt. The second experiment provided evidences that several physiological measures such as eye tracking measures and EEG spectral power in several brain regions were able to reflect a safety sign comprehensibility level in the form of cognitive load. Some nontraditional subjective measures investigated in the second experiment such as perceived cognitive load and compliance to ergonomic design principles were also able to reflect sign comprehensibility. Among the physiological measures and the nontraditional subjective measures investigated in the second major experiment, several measures such as: blinking rates, maximum and average pupil diameter, time to first fixation, EEG spectral power in prefrontal and visual cortex, perceived cognitive load, as well as compliance to ergonomic design principles were found to be consistent when applied to different types of safety signs. Consequently, we assumed that these measures could be applied across different types of safety signs. As a follow on to our study???s findings, we proposed a framework of a comprehensive safety sign evaluation utilizing the consistent measures investigated in the second major experiment, in addition to using the traditional subjective evaluation methods. We also included other factors (e.g., cultural difference, cognitive features, and ergonomic design principles) which were proven to play an important role in a safety sign redesign attempt, in our proposed framework. By this, we hope to provide adequate amount of evidences concerning a particular sign???s comprehensibility level and fill the existing gaps in the traditional safety sign evaluation and redesign approach.clos

Correction to: Eye movements and brain oscillations to symbolic safety signs with different comprehensibility

After the publication of the original article [1] it was highlighted that there was an omission regarding the online resources for the traffic signs in the section of “Experimental stimuli”

Comprehension of newly introduced water-sport prohibitive signs in Korea by westerners

The use of pictogram for prohibitive warning signs has become prevalent during the last decades since it allows international communication, and is substantial to avoid unsafe situations in public places. Although in reality these pictograms are often accompanied by text or messages to prevent people from misunderstanding the intended meaning of the symbols, there are a lot of risks of poorly designed signs being misunderstood by their intended users, especially those who are not natives. This study was aimed to examine how well a group of newly introduced water-sport prohibitive signs by MKE of Korea could be comprehended by foreigners who reside in Korea. To address this issue, an experimental study was conducted with forty Westerners. Fourteen newly introduced water sport safety signs were used as stimuli. Guessability scores were collected during the experiment, together with five cognitive sign features and detailed participants' feedback for each sign. The results showed that out of fourteen signs, only three signs conform to both ISO and ANSI requirements for safety symbols. Among five cognitive sign features, meaningfulness was found to be the best predictor for guessability score, followed by semantic closeness. Finally, by utilizing ergonomic design principles and feedback from participants, poorly comprehended signs were redesigned