Modeling Abnormal Priming in Alzheimer's Patients with a Free Association Network
ASchematic evolution of SP effects in relation to semantic memory degradation in AD (mild to moderate dementia). The figure is adapted from . Lines illustrate the hypothetical evolution of the range of SP effects according to the semantic memory deterioration in different semantic relationship conditions: close and distant category-coordinate, shared and distinctive attribute. Average normal priming effect is represented by the grey area. Hyperpriming is illustrated by lines above it. An extinction of SP is observed in the AD patients in the shared and distinctive attribute conditions, with more severe vulnerability for distinctive attributes. Simultaneously, a hyperpriming effect was observed in both close and distant category-coordinate conditions, though to a lesser extent in the latter. BAverage predicted priming (cosine similarity) results for the coordinate and attribute conditions for word pairs in . The lists have been adapted such that the words belong to our empirical dataset –FA–. When this is not possible, other items have been chosen following the criteria in the original work. The list comprehends 72 pairs (18 under the label “close category-coordinates”, 18 in “distant category-coordinates”, 18 in “shared attributes” and finally 18 in “distinctive attributes”), see Text S1. The plot shows great resemblance to the upper panel for each condition: a transient hyperpriming effect appears before the whole performance decays.