Enhanced dimension-specific visual working memory in grapheme-color synesthesia.
Bottom Line: Synesthetes displayed superior color working memory than controls for both grapheme types, whereas the two groups did not differ in grapheme working memory.Further analyses excluded the possibilities of enhanced working memory among synesthetes being due to greater color discrimination, stimulus color familiarity, or bidirectionality.These results reveal enhanced dimension-specific visual working memory in this population and supply further evidence for a close relationship between sensory processing and the maintenance of sensory information in working memory.
Affiliation: Department of Experimental Psychology, University of Oxford, UK. email@example.comShow MeSH
Related in: MedlinePlus
Mentions: Prior to the experiment, synesthetes were interviewed to corroborate their synesthesia and determine their grapheme–color pairs. Synesthetes were required to experience unique colors for at least eight digits. The eight digits that elicited the strongest synesthetic experience (by self-report) comprised the stimulus set; symbols that did not elicit color photisms, by self-report, were selected as non-inducer graphemes. All non-synesthetes reported having no grapheme–color associations. Participants first completed 2-back and 3-back practice blocks (40 trials) for the inducer and non-inducer graphemes task and then eight experimental blocks (48 trials) of inducer graphemes and four blocks of non-inducer graphemes (alternating between 2-back and 3-back blocks (e.g., Kane, Conway, Miura, & Colflesh, 2007)). All trials began with a white fixation dot for 500 ms (see Fig. 1). The centrally-presented stimulus then appeared for 500 ms. This was followed by a blank 2000 ms interstimulus interval and then the next fixation dot. Participants were instructed to respond whether the current stimulus color matched the color presented either two or three back in the sequence by depressing one of two keys, corresponding to ‘yes’ and ‘no’ responses with the index and middle fingers of their right hand, using a Cedrus response pad (Cedrus Corporation, San Pedro, CA). The mapping of key to finger was counterbalanced across participants. Following completion of the tasks, participants completed the Farnsworth–Munsell Color Hue Test.
Affiliation: Department of Experimental Psychology, University of Oxford, UK. firstname.lastname@example.org