Enhanced recognition memory in grapheme-color synaesthesia for different categories of visual stimuli

Abstract

Memory has been shown to be enhanced in grapheme-color synaesthesia, and this enhancement extends to certain visual stimuli (that don't induce synaesthesia) as well as stimuli comprised of graphemes (which do). Previous studies have used a variety of testing procedures to assess memory in synaesthesia (e.g., free recall, recognition, associative learning) making it hard to know the extent to which memory benefits are attributable to the stimulus properties themselves, the testing method, participant strategies, or some combination of these factors. In the first experiment, we use the same testing procedure (recognition memory) for a variety of stimuli (written words, non-words, scenes, and fractals) and also check which memorization strategies were used. We demonstrate that grapheme-color synaesthetes show enhanced memory across all these stimuli, but this is not found for a non-visual type of synaesthesia (lexical-gustatory). In the second experiment, the memory advantage for scenes is explored further by manipulating the properties of the old and new images (changing color, orientation, or object presence). Again, grapheme-color synaesthetes show a memory advantage for scenes across all manipulations. Although recognition memory is generally enhanced in this study, the largest effects were found for abstract visual images (fractals) and scenes for which color can be used to discriminate old/new status.

Developing Synaesthesia

“…Thus, the studies confirm that synesthetic experiences are largely internally-driven by mental representations of objects, higher-order types and semantic categories, cognitive states and events, or other internal determinants such as concepts, thoughts, moods, memories and imagery Simner, 2013;Ward et al, 2013). Another form of higher synesthesia has been observed in two different individuals who acquired their color/shape synesthesia for digits and mathematical formulas; interestingly the visual concurrents were generated in higher parietal and frontal brain regions Brogaard et al, 2013).…”

Calculative modeling for quantified semantics‐color mapping

“…Researchers believe that this cross‐media synesthesia exists among a variety of media and senses . Discussion about synesthesia first appeared in the 1800s, but it only became a systematic and popular principle in recent decades . Fruitful research over the past decade has pushed understanding and manipulation of synesthesia to a substantial level .…”

“…6 Discussion about synesthesia first appeared in the 1800s, 7 but it only became a systematic and popular principle in recent decades. 8 Fruitful research over the past decade has pushed understanding and manipulation of synesthesia to a substantial level. [9][10][11][12] From the present viewpoint, this phenomenon is commonly witnessed among visual, auditory, tactile, and other senses.…”

Does synaesthesia protect against age‐related memory loss?

“…Indeed, one of the largest studies to date found that the visual memory abilities of synaesthetes exceeded their verbal memory (Rothen & Meier, ). Moreover, the memory advantage of synaesthetes occurs irrespective of the strategy used and can occur for stimuli that are not readily amenable to mnemonic strategies such as images of fractals (Ward, Hovard, Jones, & Rothen, ; or snowflakes, as we use here). As such, we conclude that the memory advantage of synaesthetes is genuine – that is reflects ability rather than effort (Rothen et al ., ).…”