Syllable task

In this experiment our aim was to obtain further evidence as to whether the patients were able to integrate letters present simultaneously. We aimed to assess whether they could use information from syllabic structure, an interme-diate level between letters and words. Evidence in favor of syllabic processing in reading words has been mostly obtained in languages such as Italian, French and Spanish with clear syllabic boundaries (e.g. French: Ferrand, Segui and Grainger, 1996; Ferrand and New, 2003; Spanish: Alvarez, Carreiras and Taft, 2001; Carreiras, Alvarez and de Vega, 1993; Carreiras and Perea, 2002). More-over, in the study of Carreiras, Vergara and Barber (in press) colour changes coinciding with syllable boundaries lead to different evoked responses from those which did not so coincide: the manipulation of the sublexical informa-tion (i.e. of the syllabic unit) resulted in early ERP effects for both words and pseudowords in the time window of the P200. The onset latency of these effects was earlier than that of lexical variables which modulated the N400 compo-nent. This study suggests visual organization of syllabic structure as well as phonological. It is important to bear in mind that the fact that syllables are

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phonological units in speech does not necessarily imply that any syllabic ef-fects observed in visual word recognition experiments are due to the activation of phonological codes (Taft, 1979 1987; Rouibah and Taft, 2001; Alvarez, Car-reiras and Perea, 2004).

In the present experiment we investigated the ability of the patients to in-tegrate letters into orthographic syllables, by comparing different conditions:

when patients and controls were presumed to be able to process letters together (in orthographic syllables) compared to ones where this was more difficult, with nonsyllables (in condition A). The condition A has also been compared to the condition B (which comprised only syllable) where the ability to integrate let-ters into syllables was explicitly required.

Materials and procedure

A total of 80 triplets of letters was created and an ABBA design was used.

In condition A, half of the triplets were orthographic syllables (e.g. por, man, dre, gri) and the other half nonsyllables, namely not orthographically plausible syllable (e.g. tsa, dsi, igf, mhi); items were randomly presented. Patients were asked to report the triplets as 3 single letters. In condition B, all the triplets were orthographic syllables, patients were told that the 3 letters were pro-nounceable triplets and they were asked to report the triplet as a syllable. The criterion according to which triplets have been divided into orthographic sylla-bles (see Table A.1 in Appendix A) and nonsyllasylla-bles (see Table A.2 in Appendix A) is consistent with the database of the orthographic syllables in written Ital-ian (Stella and Job, 2001).

The 3 letters were presented for 165ms on a PC screen using the E-prime program; at the beginning of each trial a central fixation point appeared for 1000ms and following a 150ms ISI, the triplet was presented centrally in the screen in lower case letters, 35-point Arial font. The task has been presented to the patients and to the controls (C1, C2, C7, C8, C9, C13 and C14) and the instruction was to report the triplets as 3 single letters in condition A and as a

Condition A Condition B

Letters Syllables Nonsyllables Letters Syllables FC 187/234 80% 20/38 53% 16/40 40% 199/237 84% 46/79 58%

LDS 178/231 77% 18/38 47% 11/39 28% 213/240 89% 53/80 66%

Table 4.9: Syllable task. Performance of FC and LDS on the syllable task where subjects were asked to report the triplet as 3 single letters in condition A and as a syllable in condition B. The table shows the number of letters and triplets reported in both the conditions.

syllable in condition B.

Results

All the 7 control subjects performed the task perfectly. FC as well as LDS were distracted in one trial, so the trial was excluded from each respective analyses. One triplet (scr), considered as a syllable, was not consistent with the database of orthographic syllables in written Italian (Stella and Job, 2001), therefore it was excluded from the analysis.

The answer was considered as an ordinal variable (which can be 0, 1, 2 or 3) and the Mann Whitney test was used to analyze the data. As shown in Ta-ble 4.9, FC did not show a significant difference between conditions A and B in terms of the number of letters reported (z = -1.63, p = .10) and of the syl-lables reported (z = -.695, p = .49; Chi2³ = .25, p = .381). In addition, there was no significant difference for FC between the performance on syllables and nonsyllables in condition A (z = -1.02, p = .31). These results indicate that his performance was not sensitive to the presence of pronounceable units. By con-trast, LDS showed a significant improvement between conditions A and B in terms of the number of letters (z = -3.84, p <.0001) and the number of syllables (z = -2,03, p <.05; Chi2³ = 3.83, p <.05). This suggests that the explicit request to conjoin letters into syllables enhances her ability to put them together by

3The data have been analysed also with Chi2, by using the number of triplets reported by the patient as dependent variable.

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inducing a broader attentional window. Moreover there is a significant differ-ence between LDS’s performance on syllables and nonsyllables in condition A (z = -2.05, p <.05) and a trend for the number of triplets reported (Chi2³ = 3.3, p = .057).

Some triplets which were nonsyllables from an orthographic point of view such as tsa, dsi, mhi, qem and qer could be ambiguous from a phonological point of view (this is not the case for: etm, qco and plc). A triplet such as tsa can be pronounced as /tsa/ (which is not a phonological legal syllable in Italian) but also as /c¸a/, which is a phonological legal syllable in Italian. In that case, the assimilation in /c¸a/ is not automatic and this phonological syllable has a different orthographic representation, namely it is not written as tsa, but za (as in pizza, cozza, tazza). Another example is vho which could be pronounced as /vho/ (that is not a phonological legal syllable in Italian) but also as /vo/, which is a phonological syllable but with a different orthographic representation (as in volo, voce). However the fact that some ”orthographic nonsyllables” could be pronounced as a phonological syllable might have influenced the ability to report the 3 letters.

Therefore it was assessed whether the number of letters reported by FC and LDS in the category ”orthographic nonsyllables” was influenced by the possi-bility of being a phonological syllable. As a post-doc, the nonsyllables were divided into two groups: those which cannot be phonological syllables in Ital-ian (like bqo, etm and stc, see Tables A.1 in Appendix A) and those which might be phonological syllables (although the assimilation, when possible, is not even automatic), but in that case they would have a different orthographic repre-sentation (like like dsi, mhi and tsa, see Table A.2 in Appendix A). The Mann Whitney test was used and the results showed that the ability to report the 3 letters of the orthographic nonsyllable was not influenced by the possibility of being a phonological syllable either for FC (z = -.914, p = .420) or LDS (z = -.1.53, p = .185).

This result fits with the previous finding that FC does not benefit from a possible integration of letters, while LDS can integrate letters into ortho-graphic syllables. This capacity improves her letter identification and so in part compensates for her letter identification problems. These results show that although the performance of the patients is more impaired than that of their matched controls’, LDS retains the capacity to conjoin letters together, and that her ability is significantly more effective than FC’s even though LDS is slower than FC in word reading and in letter naming.