Effects of Display Medium and Luminance Contrast on Concept Formation and EEG Response

Abstract

Reading from a visual display terminal (VDT) has increased enormously with widespread computer use. Whether such reading affects higher cognitive processes requires study so the effect of display medium (LCD screen vs paper) and luminance contrast (1:3, 1:7, 1:11) on concept-formation performance and EEG responses was investigated. 96 men and 24 women participated in two concept-formation tasks (rule learning vs attribute and rule learning). Concept-formation performance and EEG responses were similar for stimuli displayed on paper or LCD screen. The concern that the screen may be detrimental to conception-formation performance was not confirmed; however, luminance contrast significantly affected time to complete a concept-formation task and EEG response. The middle contrast (1:7) had the smallest mean EEG power, so this contrast might be appropriate for cognitive performance. Participants' performance was significantly faster and EEG power lower for the rule-learning task than for an attribute and rule-learning task.

Memory Load and Display Polarity in Visual Search Performance and EEG Response

“…However, total time on task for negative display polarity was shorter, while the number of errors showed the opposite result. The results differ from those of a previous study when target-background luminance contrasts were 1:3 and 1:15 (Shieh & Chen, 2005) as compared to the present study in which the luminance contrast for positive display polarity was 1:8, and for negative polarity was 8:1. This might indicate sensitivity to differences in experimental conditions.…”

“…Current research also shows that electroencephalogric (EEG) measures are highly sensitive to variations in task conditions (Gevins, et al, 1997), so the need for psycho-physiological research in ergonomics has gradually been recognized (Shieh & Chen, 2005). …”

“…An early study by Berger (1969) revealed a decrease in the amplitude of the EEG α band during mental arithmetic, a first observation of the sensitivity of EEG to changes in mental effort. Current research also shows that electroencephalogric (EEG) measures are highly sensitive to variations in task conditions (Gevins, et al, 1997), so the need for psycho-physiological research in ergonomics has gradually been recognized (Shieh & Chen, 2005).…”

The Human-Computer Interface in Computer-Based Concussion Assessment

“…In addition, stimulus size (which may be influenced by proximity to the computer screen) and luminance are also critical determinants of the threshold for detecting a visual stimulus (Barlow, 1958). Indeed, some research has shown an impact of luminance on cognitive processing speed (Shieh & Chen, 2005). This issue is important because RT is a principal outcome measure yielded by computer-based tasks.…”

Comment on Evaluating Cognitive Demand

“…Thus, it seems to offer a useful alternative 'performance' measure that is reliable and valid and a useful adjunct to the work of Shieh and Chen (9).…”