Conceptual combination and language in schizophrenia

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<ul><li><p>not when compared to patients without thought disorder</p><p>Schizophrenia Research 120 (2010) 238239</p><p>Contents lists available at ScienceDirect</p><p>nia Research</p><p>.e lsedge the effects could be artifacts of patients' slowerresponses.</p><p>Given such inconsistent ndings and methodological</p><p>preted, vague or idiosyncratic responses), 15% versus 7.9%for controls (pN .1). However, the majority of otherinterpretations were produced by six patients and one control(Pomarol-Clotet et al., 2008), although the authors acknowl-Letter to the Editor</p><p>Conceptual combination and language in schizophrenia</p><p>Dear Editor,</p><p>Unconventional discourse is a noteworthy feature inschizophrenia. Semantic priming methodology underlies theinuential theory that abnormalities accessing semanticrepresentations through spreading activation within anetwork are the core mechanism for subsequent problemsforming meaningful and coherent speech (Goldberg andWeinberger, 2000). These tasks demonstrate faster responsesto words (orange) preceded by associated words (lemon)than unrelated words (desk).</p><p>However, there are limitations with this framework. First,language involves processes other than spreading activationbetween associated words. For example, in both sentencesMarcella ate the spaghetti with the marinara sauce, andMarcella ate the spaghetti with a large fork, spaghetti isassociated with and primes sauce and fork. However,understanding the former sentence requires inferring Mar-cella ate sauce but understanding the latter sentencerequires inferring Marcella used a fork to eat spaghetti.Also, most people understand ladder box as a boxcontaining a ladder even though box is not highlyassociated with ladder and unlikely to prime ladder.Indeed, language understanding requires combining familiarconcepts to create novel representations.</p><p>Second, the primary measure of reaction time differencesis both larger and more variable in patients, and corrections(e.g., priming percentage) remain problematic to interpret(Faust et al., 1999).</p><p>Third, results from semantic priming studies in patientsare variable, showing enhanced, impaired or normal spread-ing of automatic activation, or impaired controlled processing(Minzenberg et al., 2002), with thought-disordered patientsshowing enhanced priming compared to healthy controls, but</p><p>Schizophre</p><p>j ourna l homepage: wwwproblems, we assessed language understanding by explicitlyprobing interpretations of novel nounnoun expressions.People frequently combine familiar concepts into novelphrases (boomerang u) specifying referents in discoursecontexts and extending the expression of language. Crucially,there are specic rules or strategies by which novel</p><p>0920-9964/$ see front matter. Published by Elsevier B.V.doi:10.1016/j.schres.2010.04.006combinations are interpreted. We capitalized on these robusteffects and explored to what extent patients interpret novelphrases in a lawful manner. Specically, we examinedwhether patients would combine concepts to producerelation interpretations (robin snake: snake that eatsrobins), property interpretations (goose duck: duck withlong neck) or hybrid interpretations (goose duck: crossbetween a duck and a goose). Additionally, we evaluated thesimilarity effect that when combined concepts are highlysimilar (skunk squirrel) property or hybrid interpretationsare frequently produced, but when dissimilar relation inter-pretations are more likely (Parault et al., 2005; Wisniewski,1996; Wisniewski and Love, 1998).</p><p>Patients (n=24; all medicated) were from the NIMH andmet schizophrenia criteria (Structured Clinical Interview forDSM-IV). Healthy controls (n=21) were recruited throughthe NIH volunteer ofce. The study was approved by theNIMH internal review board and informed consent wasobtained.</p><p>Novel combinations of highly similar constituents (mos-quito y) and dissimilar constituents (knife truck) (fromWisniewski, 1996 experiment 2) were presented orally oneat a time and participants provided a description of the mostlikely meaning (see Table 1). Interpretations were scoredblindly as relation, property or hybrid interpretations.Misinterpreted, vague or idiosyncratic responses were scoredas other (mosquito y: mosquito that is ying).</p><p>Despite patients' overall lower intelligence (WAIS-R),verbal output (uency) and memory (WMS-R) (all psb .05),patients' and controls' performance was strikingly compara-ble: Both groups primarily produced property and hybridinterpretations to highly similar combinations (cow horse:horse that has spots) and primarily relation interpretationsto dissimilar combinations (knife truck: truck that deliversknives). For similar combinations, patients produced 71%property interpretations versus 74% for controls, and fordissimilar combinations, patients produced 81% relationinterpretations versus 85% for controls (in both cases, tb1).Patients produced more other relations (i.e., misinter-</p><p>ev ie r.com/ locate /schreswho gave 30% or more such interpretations.1 When data fromthese participants were discarded, percentages of otherresponses were equal for both groups (6.4%).</p><p>1 Importantly these patients shared similar symptom and intelligencescores to the overall group.</p></li><li><p>By explicitly probing interpretations of novel nounnounexpressionswe nd patients both interpret concepts similarlyto healthy people and use similar cognitive processes toaccess these concepts. Thus, the production of unconvention-al speech cannot be attributable to how patients representand combine concepts, since this is strikingly similar to that ofcontrols. It has been argued that accessing interpretations of</p><p>meaningful relationship between their symptoms and types</p><p>of concepts in schizophrenia, and thus the idea that</p><p>References</p><p>Faust, M.E., Balota, D.A., Spieler, D.H., Ferraro, F.R., 1999. Individualdifferences in information-processing rate and amount: implicationsfor group differences in response latency. Psychological Bulletin 125,777799.</p><p>Goldberg, T.E., Weinberger, D.R., 2000. Thought disorder in schizophrenia: areappraisal of older formulations and an overview of some recentstudies. Cognitive Neuropsychiatry 5, 120.</p><p>Minzenberg, M.J., Ober, B.A., Vinogradov, S., 2002. Semantic priming inschizophrenia: a review and synthesis. Journal of the InternationalNeuropsychological Society 8, 699720.</p><p>Parault, S.J., Schwanenugel, P.J., Haverback, H.R., 2005. The development ofinterpretations for novel nounnoun conceptual combinations duringthe early school years. Journal of Experimental Child Psychology 91,6787.</p><p>Pomarol-Clotet, E., Oh, T.M.S.S., Laws, K.R., McKenna, P.J., 2008. Semanticpriming in schizophrenia: systematic review and meta-analysis. BritishJournal of Psychiatry 192, 9297.</p><p>Titone, D., Libben, M., Niman, M., Ranbom, L., Levy, D.L., 2007. Conceptualcombination in schizophrenia: contrasting property and relation inter-pretations. Journal of Neurolinguistics 20, 92110.</p><p>Wisniewski, E.J., 1996. Construal and similarity in conceptual combination.Journal of Memory and Language 35, 434453.</p><p>Wisniewski, E.J., Love, B.C., 1998. Properties versus relations in conceptualcombination. Journal of Memory and Language 38, 177202.</p><p>Table 1Similar and dissimilar combinations used.</p><p>Similar Dissimilar</p><p>Bus truck Book plasticCow horse Bus chairCup bowl Cow cabbageGoose duck Drill pamphletIgloo tent Knife truckMosquito y Ladder boxSaxophone trumpet Motorcycle screwdriverSkunk squirrel Robin snakeTiger pony Stone rakeWhiskey beer Vase clay</p><p>239Letter to the Editorproduction of unconventional speech is attributable to thisseems improbable.</p><p>Conict of interestNone of the authors have any conicts of interest.</p><p>AcknowledgementsWe are grateful to Claire Dean for her assistance with data collection.</p><p>This research was supported in part by the Intramural Research Program ofthe National Institute of Mental Health.of interpretations (all psN .05). In conclusion, we do not ndsupport for differences in the representation and combinationnovel combinations especially relational interpretations may be differentially affected by symptoms, specicallythought disorder (Titone et al., 2007). Our patients displayeda wide range of symptoms (PANSS) but there was noB. ElvevgClinical Brain Disorders Branch, 10 Center Drive, 3C104,</p><p>MSC 1379, National Institute of Mental Health/NIH,Bethesda, MD 20892, USA</p><p>Corresponding author.E-mail address: brita@elvevaag.net.</p><p>E. WisniewskiDepartment of Psychology, University of North Carolina at</p><p>Greensboro, Greensboro, NC 27402, USA</p><p>G. StormsDepartment of Psychology, University of Leuven, Belgium</p><p>26 February 2010</p><p>Conceptual combination and language in schizophreniaConflict of interestAcknowledgementsReferences</p></li></ul>