During reading acquisition (at least in languages written with the Latin alphabet), children have to learn that the left-right orientation of letters is important (e.g., the letter “b” is different from the letter “d”). In order to do this, they have to suppress a tendency to produce vertical (left-right) mirror-confusions of letters. This tendency is based on the fundamental predisposition of the visual system to treat two objects similarly even if they differ in their vertical orientation (e.g., recognizing a face in a mirror). Interestingly, recent research suggests that even in skilled adult readers, mirror-confusions keep affecting the reading process on a subconscious level. In other words, it seems that adults unconsciously mirror letters and entire words during the early and automatic stages of visual word recognition. However, the exact mechanisms of how mirror-confusions affect reading are not fully understood yet.

In Flip, we use methods such as reaction-time measurement combined with masked priming as well as eye-movement recordings to assess the impact of mirror-confusions on the processing of letters, words and entire sentences. We conduct experiments where participants perform different tasks such as recognizing words or reading sentences that are written in different types of mirrored text.  

This allows us to answer unresolved questions about how words are recognized when mirrored and whether skilled adult readers subconsciously mirror letters and words during reading.


Are you curious and would like to learn more about the project? Would you like to participate in a study? Please contact Katharina Pittrich. We look forward to hearing from you!



Dehaene, S., Cohen, L., Morais, J., & Kolinsky, R. (2015). Illiterate to literate: Behavioural and cerebral changes induced by reading acquisition. Nat. Rev. Neurosci., 16 (4), 234-244. doi: 10.1038/nrn3924

Dehaene, S., Nakamura, K., Jobert, A., Kuroki, C., Ogawa, S., & Cohen, L. (2010). Why do children make mirror errors in reading? Neural correlates of mirror invariance in the visual word form area. Neuroimage, 49 (2), 1837-1848. doi: 10.1016/j.neuroimage.2009.09.024

Duñabeitia, J. A., Molinaro, N., & Carreiras, M. (2011). Through the looking-glass: Mirror reading. Neuroimage, 54 (4), 3004-3009. Retrieved from http://dx.doi.org/10.1016/j.neuroimage.2010.10.079 doi:10.1016/j.neuroimage.2010.10.079

Perea, M., Moret-Tatay, C., & Panadero, V. (2011). Suppression of mirror generalization for reversible letters: Evidence from masked priming. J. Mem. Lang., 65 (3), 237-246. doi: 10.1016/j.jml.2011.04.005