Conceptual combination and language in schizophrenia.

Unconventional discourse is a noteworthy feature in schizophrenia. Semantic priming methodology underlies the influential theory that abnormalities accessing semantic representations — through spreading activation within a network — are the core mechanism for subsequent problems forming meaningful and coherent speech (Goldberg and Weinberger, 2000). These tasks demonstrate faster responses to words (" orange ") preceded by associated words (" lemon ") than unrelated words (" desk "). However, there are limitations with this framework. First, language involves processes other than spreading activation between associated words. For example, in both sentences " Marcella ate the spaghetti with the marinara sauce, " and " Marcella ate the spaghetti with a large fork, " " spaghetti " is associated with and primes " sauce " and " fork. " However, understanding the former sentence requires inferring Marcella ate " sauce " but understanding the latter sentence requires inferring Marcella used a fork to eat " spaghetti. " Also, most people understand " ladder box " as a " box containing a ladder " even though " box " is not highly associated with " ladder " and unlikely to prime " ladder. " Indeed, language understanding requires combining familiar concepts to create novel representations. Second, the primary measure of reaction time differences is both larger and more variable in patients, and corrections (e.g., priming percentage) remain problematic to interpret (Faust et al., 1999). Third, results from semantic priming studies in patients are variable, showing enhanced, impaired or normal spreading of automatic activation, or impaired controlled processing (Minzenberg et al., 2002), with thought-disordered patients showing enhanced priming compared to healthy controls, but not when compared to patients without thought disorder (Pomarol-Clotet et al., 2008), although the authors acknowledge the effects could be artifacts of patients' slower responses. Given such inconsistent findings and methodological problems, we assessed language understanding by explicitly probing interpretations of novel noun–noun expressions. People frequently combine familiar concepts into novel phrases (" boomerang flu ") specifying referents in discourse contexts and extending the expression of language. Crucially, there are specific rules