Colour discrimination and categorisation in Williams syndrome

Abstract

Individuals with Williams syndrome (WS) present with impaired functioning of the dorsal visual stream relative to the ventral visual stream. As such, little attention has been given to ventral stream functions in WS. We investigated colour processing, a predominantly ventral stream function, for the first time in nineteen individuals with Williams syndrome. Colour discrimination was assessed using the Farnsworth-Munsell 100 hue test. Colour categorisation was assessed using a match-to-sample test and a colour naming task. A visual search task was also included as a measure of sensitivity to the size of perceptual colour difference. Results showed that individuals with WS have reduced colour discrimination relative to typically developing participants matched for chronological age; performance was commensurate with a typically developing group matched for non-verbal ability. In contrast, categorisation was typical in WS, although there was some evidence that sensitivity to the size of perceptual colour differences was reduced in this group.

Peripersonal Visuospatial Abilities in Williams Syndrome Analyzed by a Table Radial Arm Maze Task

“…WS has drawn the attention of cognitive neuroscientists as a result of an uneven cognitive profile with selective weak points in visuospatial abilities, and relative strength points in verbal abilities and face recognition (Atkinson et al, 2001 ; Bellugi and St George, 2001 ; Vicari et al, 2001 ; Searcy et al, 2004 ). In relation to their visuospatial deficit, WS individuals fail selectively on tasks requiring to decipher, judge, recall, and reconstruct the relationship between forms and objects (e.g., draw a house, replicate a block design, recall where an object was previously seen on a page, determine the orientation of a line; Bellugi et al, 1999 ; Mervis et al, 2000 ; Vicari et al, 2005 ; Martens et al, 2008 ; Farran et al, 2013 ; Broadbent et al, 2014a ; Farran and Dodd, 2015 ).…”

Performance on the Farnsworth-Munsell 100-Hue Test Is Significantly Related to Nonverbal IQ

“…The low-level ability to discriminate between colours (chromatic discrimination ability) also underlies development of higher-level abilities and behaviours such as colour naming 4 , affective responses to colour 5 and colour memory 6 . In recent years, colour perception has been increasingly studied in developmental disorders such as autism spectrum disorder (ASD) [7][8][9] , Attention Deficit Hyperactivity Disorder 10,11 , and Williams Syndrome 12 , as the extent of atypical sensory processing across all visual domains has become more evident in these disorders. It is therefore increasingly important to ensure that the diagnostic tools used to assess sensory processing, and in particular colour perception, are both sensitive and specific in isolating atypicalities in sensory processing.…”

“…The Farnsworth-Munsell 100-Hue Test 20 has been widely used by clinicians and visual scientists as a measure of chromatic discrimination ability 21 in both typically developing individuals with normal colour vision 22 and in individuals with congenital or acquired colour vision deficits [23][24][25][26] or developmental disorders 7,8,10,12 . The FM100 test involves arranging a set of individual coloured caps of similar lightness and saturation in order between the hues of two fixed caps (e.g.…”

Adaptive Framework for Long-term Sensory Home Training: a Proof of Principle Study

“…For instance, if monocular/binocular vision should be trained [38], the field of view and depth perception can be the target features. Similarly, the modulation of features such as wavelengths, luminance or saturation of an object, can be included in a color vision discrimination task [39]. A generic task can target different and increasingly complex skills.…”