title: Investigating letter recognition in the brain by varying typeface: an event-related potential study.
abstract: We aimed to investigate the contributions of visual letter form and abstract letter identity to the time course of letter recognition, by manipulating the typeface (i.e. font) in which letters were presented. Twenty-six adult participants completed a modified one-back task, where letters where presented in easy-to-read typefaces ("fluent" letter stimuli) or difficult-to-read typefaces ("disfluent" letter stimuli). Task instructions necessitated that participant's focus on letter identity not visual letter form. Electroencephalography was collected and event-related potentials (ERPs) were calculated relative to letter stimuli. It was found that typeface affected both early-mid (N1 amplitude and P2-N2 amplitude and latency) and late processing (450-600ms), thereby including time points whereby it is theorised that abstract identity is extracted from visual letter form (that is, 300ms post-stimulus). Visual features of the letter therefore affect its processing well beyond the currently theorised point at which abstract information is extracted; which could be explained by a feedback loop between abstract letter representations and lower-level visual form processing units, which is not included in current cognitive reading models.
authors.affiliation: Cognitive Neuroscience Laboratory, School of Psychology, Social Work and Social Policy, University of South Australia, Australia. Electronic address: Hannah.Keage@unisa.edu.au.
authors.forename: Hannah A D
authors.initials: HA
authors.lastname: Keage
authors.affiliation: Cognitive Neuroscience Laboratory, School of Psychology, Social Work and Social Policy, University of South Australia, Australia.
authors.forename: Scott
authors.initials: S
authors.lastname: Coussens
authors.affiliation: Cognitive Neuroscience Laboratory, School of Psychology, Social Work and Social Policy, University of South Australia, Australia.
authors.forename: Mark
authors.initials: M
authors.lastname: Kohler
authors.affiliation: School of Art, Architecture and Design, University of South Australia, Australia.
authors.forename: Myra
authors.initials: M
authors.lastname: Thiessen
authors.affiliation: Brain and Mind Laboratory, School of Psychology, Flinders University, Australia.
authors.forename: Owen F
authors.initials: OF
authors.lastname: Churches
mesh_terms: D000328:Adult; D001921:Brain / Q000502:physiology*; D004569:Electroencephalography; D005074:Evoked Potentials, Visual / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010364:Pattern Recognition, Visual / Q000502:physiology*; D010775:Photic Stimulation; D011932:Reading; D021641:Recognition, Psychology; D055815:Young Adult
keywords: Event-related potential; Letter recognition; Typeface