The role of level of representation in the use of paired associate learning for rehabilitation of alexia.

Patients with phonological alexia (difficulty reading pseudowords) frequently have concomitant difficulty reading functor words and verbs compared with concrete nouns. The current study compares two techniques for helping two patients with phonological alexia regain the ability to read functors and verbs. One technique follows the approach of reorganization of function, while the other relies on the stimulation approach. Study 1, employing a reorganization approach, resulted in both patients increasing their reading accuracy from approximately 10 to 90% or greater. Study 2, using a stimulation approach, resulted in significant improvement, however neither patient was able to achieve accuracy greater than 59%. Study 3 reverted back to the reorganization approach using the same words from Study 2. Both patients demonstrated significant success, achieving 90% or greater accuracy. Whereas the reorganization approach meets with far greater success than the stimulation approach, both approaches can be seen as instances of paired associate learning. An explanation of the advantage of the reorganization approach is developed which focuses on the nature of the pairings in the paired associate learning paradigm: it is proposed that pairings within the same level of representation are easier to learn than pairings that cut across levels of representation.