Affiliations: Tel Aviv University, Tel Aviv, Israel | Reuth Medical Center, Tel Aviv, Israel
Note: [] Corresponding author: Dr. Naama Friedmann, School of Education,
Tel Aviv University, Tel Aviv 69978, Israel. Tel.: +972 3 6405257; E-mail:
naamafr@post.tau.ac.il
Abstract: Does letter-form constrain errors in peripheral dyslexia? In Hebrew,
5 of the 22 letters have two different letter forms, one is used only when the
letter occurs in word-final position, the other form is used in initial and
middle positions. Is the information on final-forms encoded in the letter
identity information and used for word identification, or is it discarded? The
current research explored this question through the effect of final vs. non
final letter form on the error pattern in neglect dyslexia (neglexia) and
letter position dyslexia (LPD). Left word-based neglexia results in errors of
omission, substitution and addition of letters in the left side of words, which
in Hebrew is the end of the word. We examined whether final letter form blocks
the addition of letters to the end of the word and whether omissions of letters
after letters in non-final form are avoided. The predominant error type in LPD
is migration of letters within words. We tested whether migrations also occur
when they cause form change of either final-form letters that move to middle
position or middle-form letters that move to final position. These questions
were assessed in both acquired and developmental neglexia and LPD. The results
indicated a strong effect of final letter-form on acquired neglexia and on
acquired and developmental LPD, which almost completely prevented form-changing
errors. This effect was not found in developmental neglexia, where words that
end in final-form letters were actually more impaired than other words,
probably because final-form letters appear only on the neglected side of the
word for Hebrew-reading children with left developmental neglexia. These data
show that early visuo-orthographic analysis is sensitive to final letter form
and that final letter form constrains errors in peripheral dyslexia.
