Where is January? The month-SNARC effect in sequence-form synaesthetes.
Two experiments compared the SNARC effect for calendar months (January-December) in 16 normal controls against four participants reporting a common but little-studied variety of synaesthesia where ordinal sequences are explicitly experienced in elaborate spatially extended patterns (spatial forms). The SNARC effect (spatial-numerical association of response codes) (Dehaene et al., 1993) in which responses to early versus late members of ordinal sequences show left-hand versus right-hand reaction time (RT) advantages, respectively, has previously provided evidence for implicit associations between sequential and spatial representation in non-synaesthetes (Gevers et al., 2003). The current study revealed an automatic month-SNARC effect for the synaesthetes, with the left/right-hand advantage reversing for synaesthetes who experienced early months on the right rather than the left of their roughly circular year forms. The absence of any month-SNARC effect among 16 controls demonstrated cognitive differences in sequence representation between controls and synaesthetes, but failed to replicate previous findings for non-synaesthetes. Certain details of the synaesthetes' SNARC effect may also constrain the way SNARC effects in non-synaesthetes are interpreted.
Price
Mark C
MC
Psychology Faculty, University of Bergen, Bergen, Norway. mark.price@psysp.uib.no
Mentzoni
Rune A
RA
D000328:Adult; D000704:Analysis of Variance; D016022:Case-Control Studies; D005260:Female; D007839:Functional Laterality / Q000502:physiology; D006801:Humans; D007092:Imagination / Q000502:physiology; D046709:Pattern Recognition, Physiological; D010468:Perceptual Disorders / Q000503:physiopathology* / Q000523:psychology; D011930:Reaction Time / Q000502:physiology; D012016:Reference Values; D012691:Serial Learning / Q000502:physiology*; D013028:Space Perception / Q000502:physiology*