Human brain can mentally rotate words reflected in a mirror around and understand them automatically and unconsciously, at least for a few instants, a team of scientists from the Basque Centre on Cognition, Brain and Language (BCBL) has shown.
The finding could pave way to better understand dyslexia.
"At a very early processing stage, between 150 and 250 milliseconds, the visual system completely rotates the words reflected in the mirror and recognises them, although the brain then immediately detects that this is not the correct order and 'remembers' that it should not process them in this way," said lead author Jon Andoni Dunabeitia.
Dunabeitia and his team used electrodes to monitor the brain activity of 27 participants while carrying out two experiments in front of a computer screen.
In the first, the participants were shown words with some of the letters and other information rotated for 50 milliseconds (an imperceptible flash, which is processed by the brain); while in the second case the entire word in the mirror was rotated (for example HTUOM instead of MOUTH).
The results of the encephalogram showed in both cases that, at between 150 and 250 milliseconds, the brain's response upon seeing the words as reflected in the mirror was the same as when they are read normally.
"These results open a new avenue for studying the effects of involuntary rotation of letters and words in individuals with reading difficulties (dyslexia) and writing problems (dysgrafia)," said Dunabeitia.
"A tiger is a tiger on the right side and the left side, but a word read in the mirror loses its meaning - although now we know that it is not as incomprehensible for our visual system as we thought, because it is capable of processing it as if it were correct", the researcher concluded.
The study has been published in the journal NeuroImage.