Visual implicit memory deficit and developmental surface dyslexia: A case of early occipital damage

This study reports the case of EBON, a fifteen-year-old right-handed female Swedish student, who suffered an early medial/dorsal occipital brain lesio n and showed a clearly defined pattern of developmental surface dyslexia. E BON and 17 controls were examined with within and cross-modality (visual an d auditory) word stem completion tasks together with tasks requiring free-r ecall and recognition for visually and auditory presented words. Compared t o age-matched controls, EBON was found to show a significant deficit of vis ual priming following visual presentation, and a deficit approaching signif icance following auditory presentation. Explicit memory and visual and spat ial abilities were not significantly different from controls. Therefore, EB ON represents the first childhood case establishing the role of occipital r egions in visual priming, as well as illustrating a profile of surface read ing difficulty as a developmental consequence of this locus of lesion.