posted on 2023-06-09, 16:15authored byMarie Rosanna Rogers
Colour perception is formed of many different components, such as colour discrimination, colour constancy, colour term naming, and the dimensions of colour (hue, chroma and lightness). It is a ‘toolbox’ of processes, not one cohesive function. Some of the components of colour vision develop into adult-like function over childhood, but they do not necessarily mature at the same speed. The studies in this thesis investigate adult, child and infant colour perception and cognition. Paper 1 finds a relationship between colour constancy and colour term naming in three- to four-year-old children. This relationship has wider implications for the co-development of language and perception. Paper 2 (Rogers, Knoblauch & Franklin, 2016) uses the technique of Maximum Likelihood Conjoint Measurement (MLCM) in adult participants to investigate the interaction between lightness and chroma in perception. Paper 3 combines MLCM analysis with preferential looking methods to compare interaction of lightness and chroma in infant and adult participants. This study paves the way for the use of MLCM and eye-tracking for studying other dimensions in development such as face perception, language, surface and shape. Paper 4 investigates why discrimination is poorest along the blue-yellow direction of cone opponent space (also known as the daylight locus). We tested the theory that this is adaptive for colour constancy by comparing illumination discrimination to surface discrimination in adult participants. We found equally poor discrimination for blue-yellow in both conditions, suggesting colour constancy is not the only explanatory factor. Together, these papers add to our understanding of the key components of colour vision over the life span and how perception of colour depends on various contextual and individual factors. Furthermore, this thesis develops novel applications of experimental techniques, and paves the way for these methods to be used to study other cognitive and developmental domains.