Using colours to assess the intensity of emotions and pain: a validation of two coloured visual analogue scales

Visual Analogue Scales (VAS) are widely used in clinical and research settings to measure subjective experiences. Coloured versions (Colour Analogue Scales - CAS) have been proposed for emotions in specific samples such as children and people suffering from cognitive deficits. To date, data on the comparability of the two types of measures are meagre. The present study fills this gap by recording the perceived intensity of emotions and pain experienced by healthy adults ( N = 128, mean age = 21.64 ± 3.36, 62 females, 66 males). In Experiment 1, the participants rated the valence of emotions in human faces using a VAS and a coloured scale (E-CAS), with yellow representing happiness and blue grey representing sadness. In Experiment 2, they rated the imaginary pain intensity typically associated with certain daily life situations, in this case using a VAS and a red-shaded CAS. The results from the two scales were compared. Convergent and concurrent validity were assessed in correlation analyses, while construct validity was examined using repeated-measures analyses. Response times were compared to evaluate the potential effects of format. High correlations and comparable sensitivity were found between the CAS and VAS scales. Crucially, responses to the coloured scales were faster than the VAS, suggesting a reduced cognitive load in their use, that makes them potentially indicated for patients with cognitive deficits.