title: Evidence for letter-specific position coding mechanisms.
abstract: The perceptual matching (same-different judgment) paradigm was used to investigate precision in position coding for strings of letters, digits, and symbols. Reference and target stimuli were 6 characters long and could be identical or differ either by transposing two characters or substituting two characters. The distance separating the two characters was manipulated such that they could either be contiguous, separated by one intervening character, or separated by two intervening characters. Effects of type of character and distance were measured in terms of the difference between the transposition and substitution conditions (transposition cost). Error rates revealed that transposition costs were greater for letters than for digits, which in turn were greater than for symbols. Furthermore, letter stimuli showed a gradual decrease in transposition cost as the distance between the letters increased, whereas the only significant difference for digit and symbol stimuli arose between contiguous and non-contiguous changes, with no effect of distance on the non-contiguous changes. The results are taken as further evidence for letter-specific position coding mechanisms.
authors.affiliation: Basque Center on Cognition, Brain and Language, Donostia, Spain. s.massol@bcbl.eu
authors.forename: Stéphanie
authors.initials: S
authors.lastname: Massol
authors.forename: Jon Andoni
authors.initials: JA
authors.lastname: Duñabeitia
authors.forename: Manuel
authors.initials: M
authors.lastname: Carreiras
authors.forename: Jonathan
authors.initials: J
authors.lastname: Grainger
mesh_terms: D000704:Analysis of Variance; D005260:Female; D006801:Humans; D007600:Judgment; D008297:Male; D010364:Pattern Recognition, Visual / Q000502:physiology*; D010775:Photic Stimulation; D011597:Psychomotor Performance / Q000502:physiology*; D011930:Reaction Time / Q000502:physiology*; D011932:Reading; D055815:Young Adult