From his description I doubt it's synaesthesia. Usually it's a crossover in a fundamental perception (taste, smell, etc.), rather than an elaborate sensation "feeling as if it is jumping out." Also, it varies per-individual, suggesting that "eager" could have just as well seemed to, for example, "a monster that eats everything in its path."

My feeling is this is just a very strong "coupling" of vocabulary to the emotional centers. Fast activation, in other words. If this is the case, I also suspect it wouldn't correlate very much to anagram-solving ability.