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Partial direct pathway lesions in the dyslexia model, either with or without an intact semantic pathway (Full Sem vs. No Sem, respectively). The highest levels of semantic errors (i.e., deep dyslexia) are shown with Full Sem in the abstract words, consistent with the simpler results showning this pattern with a full lesion of the direct pathway.
Partial semantic pathway lesions in the dyslexia model, with an intact direct pathway. Only visual errors are observed, and damage to the orthography to semantics hidden layer (OS_Hid) seems to be more impactful than the semantics to phonology (SP_Hid) layer.
Partial semantic pathway lesions with complete direct pathway lesions. The 0.0 case shows results for just a pure direct pathway lesion. Relative to this, small levels of additional semantic pathway damage can produce slightly higher rates of semantic errors.
The graphs here show the effects of partial damage to either the direct or semantic pathway, in combination with full damage to the other pathway in some cases, in the Dyslexia simulation. Although numerical differences are present for different damage levels, the qualitative patterns from the complete lesions are highly robust. It is not necessary to postulate multiple sources of damage to account for deep dyslexia, for example.