From Lachmann & van Leeuwen (2005a): Examples of Garner patterns used in a Goodness rating task (Garner & Clement, 1963). 

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... having complemented my view on the mission of a science of visual Ge- stalten in the humanities with a perspective on how it should engage the sciences, I will proceed to demonstrate with an example, how some of this can sometimes be accomplished, albeit on a small scale, in everyday science. Everyday science is a rather un-heroic activity, and we should not expect too much in the way of battles, charges, or revolutions. Science is a trench war. So what, if unspectacular, are the victories we should be able to carry from the trenches? To illustrate this part I turn to the subject of developmental dyslexia. More than 100 years of scientific research have failed to provide a consistent account of developmental dyslexia (Miles & Miles 1999). Controversies are rife, such as whether the deficit in reading ability mainly resides in visual processing (Hulme 1988; Lovegrove, Bowling, Badcock & Blackwood 1980; Skottun 2001; Slaghuis & Ryan 1999; Stanley & Hall 2005; Stein 2001; Willows 1998) or is phonological in nature (Rack & Olson 1993; Siegel 1993; Snowling 2991; Vellutino 1987; Vellutino, Steger, Moyer, Harding & Niles 1977). In particular, it has been observed that dyslexics perform similar to unimpaired readers in many visual tasks (see Willows, 1998 for a review). Some researchers, therefore, concluded that visual processing deficits are not involved in the syndrome (Vellutino 1987; Vellutino, et al. 1977). However, as I will argue, this conclusion is premature. The conclusion is premature, because visual Gestalten, are left out of the equation. The perceptual organization of letters and shapes differ, as Koffka had already noted. As shapes, b and d are similar; as letters they are not. Their sym- metry is usually not noticed, at least not in normal adult readers, in letters. We propose that normal readers suppress the symmetry in individual letters, as it is not helpful in reading. This may be part of an overall strategy to process letters more analytically in the early processing stage of reading, than comparable fig- ures. With anomalous readers, i.e. dyslexics, we might expect anomalies in their processing strategy. My colleague, Thomas Lachmann, and I recently published a number of studies involving the perception of symmetry in letters and shapes, several of which in- volves dyslexics. One of these (Lachmann & van Leeuwen, 2007) I will review here for its potential “missionary” implications. This requires me to discuss the results of this study in some detail. Previously we had published a series of studies using Garner patterns (Garner, 1962) in a same-different task. Garner patterns (Figure 1) are five-dot patterns construed on a 3x3 grid leaving no row or column empty. These patterns differ in their perceived Goodness (Garner & Clement, 1963). Gar- ner showed that this could be predicted by the notion of equivalence set size (ESS). Some patterns can be transformed into each other by combinations of 90 o rotation or mirror image transformations. The ones thus linked by combinations of one or more transformations constitute an equivalence class. The number of members in the class constitutes its ESS. The more reflectional or rotational symmetry of a pat- tern, the smaller is its ...