Ergonomic implications of manual interaction with visual displays (new title)

• Applicant: Dr.-Ing. Wolfgang Jaschinski
• Subject Area: Human Factors, Ergonomics, Human-Machine Systems
• Term: from 2009 to 2015
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 161182747

Touch screens and hand-held devices are now readily available and allow for a more flexible and better ergonomic design of computer workplaces. What is interesting, but often ignored, about these devices from an ergonomics perspective is that various cognitive functions have been found to change when people are asked to hold their hands near visual displays. In the first phase of this project (DFG JA 747/5-1), we found that hand proximity (1) can benefit visual perception - however in different ways for different individuals (left- vs. right-handers, young vs. old adults), and (2) can also improve both sensory fusion and accommodation. Placing the hands near a display can have beneficial effects on cognitive performance. However, it can also have detrimental effects, as we showed in a task which involved searching for specific letters in a text. Thus, the influence of hand proximity on performance depends on the type of task, and thereby the type of function, one is examining. This needs to be considered for ergonomic implications of hand-proximity effects. Surprisingly, almost all studies in this area are based on the hands being statically held in place, which is not representative of how people actually interact with hand-held devices. Therefore, the general aim of this grant extension is to focus on the practical implications of manually interacting with visual displays in meaningful ways. In particular, we want to establish how hand-proximity effects change and potentially improve cognitive functions. This will be done by employing experimental tasks that simulate tasks at the workplace and that reflect different aspects of cognitive processing (perception, attention, memory) that are relevant for interacting with touch and hand-held devices.Another objective is to further investigate the influence of hand-proximity and manual interaction on oculomotor functions. Recordings of binocular eye movements will be used to measure accommodation and binocular coordination in basic visual tasks, as used in clinical optometry, and more complex ones, such as reading. The final objective is to explore the influence of aging and individual differences on hand-proximity effects. The influence of age is interesting because people of all ages are increasingly being confronted with interactive visual displays. Moreover, we previously showed that younger and older adults have different patterns of static hand-proximity effects. To explore the role of individual differences, we want to investigate the relationship between subjective judgments of mental effort and visual strain, and objective task performance, such as task speed and accuracy. This should be helpful in understanding how people come to prefer one type of device or interaction over another. We hope to help develop useful ergonomic recommendations for the computer workplace by studying how users experience and perform tasks when they manually interact with visual displays.

• DFG Programme: Research Grants
• International Connection: France
• Participating Persons: Dr. Nathalie Le Bigot; Dr. Stephanie Jainta