This paper is primarily concerned with one variation of synaesthesia; graphemecolour synaesthesia. In which the presentation, or concept, of graphemes elicits a coloured sensation. Similarities exist between synaesthetes’ and non-synaesthetes’ letter-colour associations, which has led to suggestions that synaesthesia may be an extension of normal perception (Simner et al., 2005). Non-synaesthetes were found not to use the frequency heuristic used by grapheme-colour synaesthetes (Simner et al., 2005). However, we re-tested this using a Stroop methodology. The findings here support those made originally, but we further claims regarding synaesthesia being an exaggeration of normal perception. The remainder of the study uses a mix of Stroop and SNARC (the Spatial-Numerical Association of Response Codes) methodologies to assess the direction of the shading pattern of non-synaesthetes mental representation for the alphabet and also the shading pattern of mental-space in general. We were able to support the hypothesis that the alphabet may be shaded from light to dark from A to Z (Julia Simner, personal communication), but were unable to fully support the claim that mental-space in general may be shaded from dark to pale from left to right (Peter Walker, personal communication). In addition, we point out possibilities for future research concerning these areas.