Visuo‐spatial representations of the alphabet in synaesthetes and non‐synaesthetes

Abstract

Visuo-spatial representations of the alphabet (so-called 'alphabet forms') may be as common as other types of sequence-space synaesthesia, but little is known about them or the way they relate to implicit spatial associations in the general population. In the first study, we describe the characteristics of a large sample of alphabet forms visualized by synaesthetes. They most often run from left to right and have salient features (e.g., bends, breaks) at particular points in the sequence that correspond to chunks in the 'Alphabet Song' and at the alphabet mid-point. The Alphabet Song chunking suggests that the visuo-spatial characteristics are derived, at least in part, from those of the verbal sequence learned earlier in life. However, these synaesthetes are no faster at locating points in the sequence (e.g., what comes before/after letter X?) than controls. They tend to be more spatially consistent (measured by eye tracking) and letters can act as attentional cues to left/right space in synaesthetes with alphabet forms (measured by saccades), but not in non-synaesthetes. This attentional cueing suggests dissociation between numbers (which reliably act as attentional cues in synaesthetes and non-synaesthetes) and letters (which act as attentional cues in synaesthetes only).

Automaticity in sequence-space synaesthesia: A critical appraisal of the evidence

“…Consistent with our view, one recent study of synaesthetic cueing effects, not listed in Table 1, specifically failed to obtain significant cueing effects at short CTOAs (Jonas et al, 2011). This study differed from those discussed so far in that it tested a group of 13 people with spatial forms for the alphabet, using letters as cues, and the dependent variable was RT to initiate saccades to lateralized targets (rather than a key press).…”

“…(e) As discussed by Price (in press), the layout of spatial forms often creatively expresses the significance of a sequence member in terms of its spatial extension (e.g., holiday months taking up more space than other months; see also Diesendruc et al, 2010), or in terms of bends or protuberances in the trajectory of a form. For example, calendar forms may bend or distort at personally significant dates, number lines often bend at decade breaks (Makioka, 2009;Sagiv et al, 2006), the number 12 tends to be emphasised in older samples of British number lines, reflecting the use of the duodecimal system (Galton, 1880a;Phillips, 1897), and bends and breaks in alphabet forms tend to reflect the verbal parsing of the Alphabet Song that is often used to teach the alphabet sequence in English speaking countries (Jonas et al, 2011). This symbolic use of imagery may overlie more innate tendencies to arrange spatial forms in particular ways, as illustrated by the recent finding that the clockwise versus anticlockwise direction of circular forms for the calendar months is correlated with synaesthetes' handedness (Brang et al, 2011).…”

“…Using a similar procedure to the numeral cueing study of Further recent studies have continued to explore cueing effects arising from written names of various types of sequence member, including months for participants with month forms, numerals for participants with number lines, weekdays for a participant with a weekday form, clock times for a participant with a vivid involuntary image of a clock face, and letters for participants with forms for the alphabet sequence (Hubbard et al, 2009;Jarick et al, 2009aJarick et al, , 2009b2011a;2011b;Jonas et al, 2011;Teuscher et al, 2010). The cueing effects observed in these participants again differed from those of control participants, and seem to reflect the relative left-to-right or bottom-to-top locations of sequence members in the synaesthetes' reported forms.…”

Developing Synaesthesia

“…This view sometimes links spatial forms to normal processes of implicit spatial representation of magnitude Simner, 2009). Others suggest spatial forms are continuous with standard varieties of visuospatial mental imagery and best understood as a residue from childhood strategies for encoding abstract verbal sequences (Galton, 1880Price, 2009, in press;Jonas et al, 2011;.…”

Number-space associations in synaesthesia are not influenced by finger-counting habits

“…For example, right-handed timespace synaesthetes with circular month forms tend to perceive the months as being laid out in a clockwise format, while left-handed synaesthetes' circular layouts are more commonly anticlockwise (Brang, Teuscher, Miller, Ramachandran, & Coulson, 2011). Similarly, the need to take a breath at certain points when reciting the alphabet seems to have shaped the breaks, bends and other features seen in alphabet-space synaesthesia (Jonas, Taylor, Hutton, Weiss, & Ward, 2011). …”