Reading in the Brain and Mirror Writing

Stanislaus Dehaene has a new book entitled Reading in the Brain: The Science and Evolution of a Human Invention and he has been kind enough to publish chapter summaries and all color figures here.

From Chapter 7, a discussion of how mirror reading is thought to be a loss of generalization ability (recognizing that b is related to d, for instance) that occurs as children grow older. At left, Orton's original thought that mirrored letter mistakes resulted from a failure to inhibit the perception in the opposite hemisphere; at right, the current theory that mirror 'mistakes' occur from the retention of a generalization ability rather than a real mistake. The generalization ability is a good thing for young children because it helps them recognize their parents and their world from different angles.

In our own family, I remember being surprised when our then young son brooded over how to write the letter "f"... he said, "f, f, f,... oh that's right, it's a flipped over 'j' with a line through it." Huh? I hadn't even thought about the relationship between the letter 'f' and 'j' before that. To this day both he and Brock are able to read words backwards more quickly than me. There are advantages to this mirror ability (as well as disadvantages of course) - usually in the ability to rotate objects and perceive from different angles (like Tesla turning an apparatus around in his mind), and not surprisingly, we often see this talent among the spatially-talented dyslexics that we see. Our loss of mirroring ability is therefore more of a 'mistake', likely reflecting the same process that we discussed in The dark side of expertise.

In the figure at right, the bar graph shows how mirroring is common condition in children below the age of 8 years. Above the graph, the writing observations of Cornell that 5 year old children are more like to write their name backwards when not given enough room for left-to-right writing. Lissie and Meggie were sisters. Lissie was 5 and Meggie, 6.

Below, an example of Leonardo Da Vinci's mirror writing.

For more from Dehaene on mirror writing: Why do children make mirror errors while reading? pdf


  1. Anonymous5:45 PM

    Thank you so much for posting the information about Stan Dehaene's new book. It is marvelously done, and it's incredible to have the concise chapter summaries and all the figures on your website link. The only disappointment is that after Dehaens teases out all the pieces of visual processing that work in parallel to convert orthography into the act of reading, he concludes the book in looking for phonemic breakthroughs to recalcitrant reading. In that regard, it is basically an elaboration of the Shaywitz approach that acknowledges the influence of visual processing, but trivializes any role that visual input factors have on the reading process. Elsewhere on your blog you have excellent information about visual processing, including the story of "Stereo Sue", who wrote courageously about how much she struggled with reading as a child. Her story champions looking at vision beyond eyesight, and the confluence of bottom-up and top-down processes in optometric vision therapy. Perhaps one day those in the reading/dyslexia remediation field will move beyond paying vision therapy lip service.

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  3. Anonymous5:26 AM

    just ordered the book from amazon 18.45. i'm so excited. my son is 12yo and dyslexia and sssooo freakin smart. he is always asking me questions and now i have the book to tell him about how his brain works!!