Enhanced Spatial Navigation Skills in Sequence-Space Synesthetes

Abstract

Individuals with sequence-space synesthesia (SSS) perceive sequences like months, days and numbers in certain spatial arrangements. Several cognitive benefits have been associated with SSS, such as enhanced mental rotation, more vivid visual imagery and an advantage in spatial processing. The current study aimed to further investigate these cognitive benefits, focusing on spatial navigation skills, to explore if their enhanced sensitivity to spatial relations is reflected in enhanced navigational performance. Synesthetes were distinguished from controls by means of a questionnaire, a consistency test and drawings. A virtual Morris Water Maze (MWM) task with two allocentric and two egocentric navigation conditions was used to assess spatial navigation abilities. For the allocentric tasks, participants had to use object cues to find a hidden platform and for the egocentric tasks, they had to use their own position as a reference. Results showed that synesthetes performed significantly better compared to controls on the allocentric and egocentric tasks that reflected real life situations more accurately. However, this significant result was only found for the time taken to find the platform and not for the length of the path that was taken. In exploratory analyses, no significant relations were found between task performance and the specific features of the manifestation of each individual’s synesthesia. Our hypothesis that synesthetes with the ability to mentally rotate their spatial arrangements would perform better on the allocentric task was not confirmed. Results add to the growing body of literature concerning the cognitive benefits of SSS and are consistent with the possibility that enhanced spatial navigation skills emerge from generally enhanced visuospatial abilities in SSS.

Autistic traits in synaesthesia: atypical sensory sensitivity and enhanced perception of details

“…For details on SSS classification, see fig. 7 and the supplementary material of Van Petersen et al [57]. One synaesthete's SSS did not meet diagnostic criteria and another synaesthete reported autism; one control reported grapheme-colour synaesthesia.…”

“…Participation followed on a spatial navigation experiment [57]. SSS was verified by means of an online screening questionnaire, a consistency test and a drawing test [57]. The consistency test was a spatial computer task [58], in which participants indicated the location of their synaesthetic experiences [57].…”

“…Twenty sequence-space synaesthetes and 21 non-synaesthetes took part in the experiment taking place in the laboratory. Participation followed on a spatial navigation experiment [57]. SSS was verified by means of an online screening questionnaire, a consistency test and a drawing test [57].…”

“…SSS was verified by means of an online screening questionnaire, a consistency test and a drawing test [57]. The consistency test was a spatial computer task [58], in which participants indicated the location of their synaesthetic experiences [57]. Participants' drawings of days, months and numbers allowed verification of SSS by visual inspection of the drawings' characteristics.…”

“…Questionnaires and visual tests were identical to Study 1. Participants were invited to the laboratory on the basis of the SSS screening questionnaire and first completed the consistency test, drawing task and spatial navigation task as described in Van Petersen et al [57]. Next, the motion coherence task and the embedded figures task were completed, running in Google Chrome on a Dell Windows 7 computer with a 24 0 BenQ screen (1920 × 1080 resolution).…”