Effect of Non-Visual Stimulus on Color Perception

Abstract

The subjective perception of color and overall quality (age, abrasion, uniformity, etc) of textile products cannot always be characterized by physical measurement of the textile substrate alone. Color perception, for instance, is greatly influenced by factors such as the complexity of the viewing environment, mood, fatigue and stress. It is also known that certain stimuli can influence the subjective judgment of other stimuli.

In view of the critical role that color perception plays in the commercial success of almost all manufactured products, particularly consumer products such as apparel garments, it is important to determine the influence of non-visual stimuli that are not commonly controlled (e.g., tactile response) on the visual response of the average observer. Accordingly, this study is concerned with the possible influence of two non-visual stimuli, tactile response and odor, on the perception of the magnitude of color difference between two dyed fabric samples. It was considered that the ability to influence an observer's color perception by deliberately modifying one or more of the non-visual stimuli could lead to new avenues of research and development into optimized perception of color, wear and overall quality of textile products.

Large samples of 100% knit cotton fabric were dyed with fiber-reactive dyes to six hues of two depths of shade using a cold pad-batch method. Each sample was cut into four pieces and three were subjected to 1, 5 or 10 wash-and-dry laundering cycles. Each of these samples was after-treated with either stiffening or softening agent. Then 25 - 30 trained observers were trained to visually assess the samples, with and without a tactile sensory input. Also, selected samples were assessed with and without a pleasant odor of lavender or orange oil fragrance.

Statistical analysis showed that color difference perception was influenced by tactile response. Observers rated samples as having a lower color difference when they assessed samples with soft hand compared to equivalent samples that were perceived to be very stiff.

Statistical analysis also showed that color-difference sample pairs with an orange hue exhibited significantly lower perceived color difference in the presence of orange oil fragrance than when no observable fragrance was present. However, the effect of orange oil fragrance on the color difference perception of other hues did not exhibit a statistically significant effect. Also, the presence of a lavender fragrance did not significantly affect the color difference perception of any hues.