TACTILE EMBEDDED FIGURES TASK (i) Materials

The test was designed to be a tactile equivalent of the Visual Embedded Figures Task. The target shape was the raised outline of a square made from strips of balsa wood and mounted on a wooden board. The discrimination, practice and ^ Raw Vocabulaiy Score: r(39)=0.45, p< 0.004; Raw Similarities Score:

r(39)=0.50, p < 0.002; Raw Block Design Score: r(39)=0.58, p <0.0005; Raw Object Assembly Score: r(39)=0.50, p< 0.002).

experimental items were constructed in the same way, and took a similar format to those used in the visual test. However, the experimental (and practice) items contained the shape hidden inside a geometric figure as opposed to an outline of a familiar object. The two practice and eleven experimental figures can be seen in Appendix 6. The geometric format drew upon the work of Thurstone (1944) but most of his designs were unsuitable for this type of test, and so figures which would be more appropriate for use with children in the tactile modality were designed to form a series of increasing difficulty.

(ii) Procedure

The figures were concealed from the child at all times behind a thick velvet curtain. The child slipped one or both hands underneath the curtain to explore the figures which were secured to the desk top as they were presented. The procedure was similar to that in the visual test. The child was helped to trace round the target square, and then had to discriminate this square from selections of similar shapes mounted separately on the same board in order to familiarise them with its shape, size and orientation. This was followed by the practice trials to acquaint the child with the disembedding task. The child was instructed to trace round the outline of the figure before attempting to find the hidden square, and to indicate the location of the square by tracing round its edges with their finger. It was explained that the square might have lines within it and that they should not be put off by this. All the experimental items were presented to each child. During the experimental trials, the child was allowed to retrace the target square only if they specifically requested to, or failed on three consecutive items.

(iii) Results

The results were expressed as percentage correct (see Table 9). An analysis of variance was conducted on the data with one between-subjects factor, groups (developmental dyslexies, reading age and chronological age controls). A main

TABLE 9

TACTILE EMBEDDED FIGURES TASK: Mean Percentage Accuracy (standard deviations in brackets)

READING GROUP MEAN % ACCURACY

READING AGE 22.39 CONTROLS (16.65) DEVELOPMENTAL 43.90 DYSLEXICS (23.44) CHRONOLOGICAL AGE 48.56 CONTROLS (24.02)

effect of groups was found (F(2,120) = 17.07, p < 0.0005). Newman-Keuls tests showed that developmental dyslexies performed at a similar level to their chronological age controls on this task, and that the performance of both of these groups was superior to that of the reading age controls.

(iv) Discussion

The developmental dyslexies performed at the same level as their chronological age controls. Moreover, the distribution of these groups' scores was very similar. The reading age controls were significantly less accurate at locating the hidden figures, suggesting that the tactile skills involved in this task improve with chronological age.

It is reassuring to find that the developmental dyslexies can perform at a level appropriate for their chronological age in this task since it implies that the impairments that have already been found reflect specific areas of difficulty rather than a general depression of performance in the dyslexic group.

The finding that the performance of the dyslexic children was appropriate for their age in this sensory modality could have important remedial implications. Hulme (1981) reported that manual tracing improved dyslexic children's recall of visually presented letters and nonverbal forms. He suggested that developmental dyslexies generally relied upon a visual memory code for recall. Manual tracing provided an equivalent source of information to describe the forms which could combine with the visual information to aid recognition.

Although Hulme's experiment was limited to short-term retention, he quoted studies testifying to the durability of motor memory.^ The success of multisensory teaching methods appeared to confirm the effectiveness and durability of kinaesthetic learning. Schevill (1978) argued that tactile learning led to better alphabetic recognition and to better serial ordering and retention of the distinctive features of letters. Fernauld (1943) developed the Fernauld Tracing Technique and advocated ^ See also Baddeley (1975).

that children be taught by requiring them to trace written words with their fingers. Each word was traced in a single movement with concurrent vocalisation of the word. Then the child attempted to write the whole word from memory. In the case of error or interruption the child had to begin once again. This procedure was repeated until the spelling of the word could be reproduced correctly from memory. This and similar methods have been widely used with developmental dyslexies and have been claimed to be highly successful (see Cotterell, 1970).

Among the dyslexic children, performance in the Tactile Embedded Figures Task correlated with reading age (r(39)=0.48, p < 0.003). There was also an association between this task and spelling age (r(39)==0.43, p < 0.007) but this relationship did not reach significance after reading age was partialled out (r(38)=0.16, p>0.05). It may be that some literacy skills are being consolidated via written language for the dyslexic children with good tactile skills. The Tactile Embedded Figures Task also correlated with the dyslexic children's performance in the middle condition (r(39)=0.38, p<0.02) and the final condition (r(39)=0.34, p<0.03) of the Auditory Organisation Task. It will be recalled that a similar relationship existed for this group's performance on the Visual Embedded Figures and Auditory Organisation Tasks.

The only correlates of the Tactile Embedded Figures Task among the reading age controls were the raw scores for the performance subtests of the WISC-R: Block Design (r(39)=0.46, p< 0.003) and Object Assembly (r(39)=0.42, p< 0,007), The scores obtained by the chronological age controls on the Tactile Embedded Figures Task correlated with their age (r(39)=0.58, p < 0.0005), their raw scores on the Digit Span subtest of the WISC-R (r(39)=0.38, p<0.02) and their nonword spelling accuracy (r(39)=0.33, p<0.04). An additional correlation with the Auditory Organisation Task just missed significance (r(39)=0.31, p< 0.052).

Performance on the Visual and Tactile Embedded Figures Tasks correlated significantly in both the dyslexic group (r(39)=0.48, p < 0.002) and the chronological age control group (r(39)=0.51, p< 0.002). An association between

visual and tactile performance in similar tasks was also reported by Axelrod & Cohen (1961) in a study of adult subjects. They attributed this to a reliance upon visualisation of the solution of the tactile figures on the basis of the retrospective accounts given by their subjects. This is one possible explanation of the correlation found in the present study because the children would sometimes spontaneously give the geometric name of the shape that they felt or make a visual analogy about its appearance e.g. "it's like a bow-tie!".

Nevertheless, the difference in the level of accuracy shown by the developmental dyslexies in the two tasks may be attributable to there not being the same spontaneous perception of the overall figure as a gestalt in the tactile modality as exists in the visual modality. Difficulty in segmenting a meaningful picture into its parts may have caused some dyslexic children particular problems. Indeed, the common factor accounting for the correlation between the tests may not be the segmental aspects of these tasks but an extrinsic element, such as the attentional skills required in order to search for the hidden figure.