A computational language approach to modeling prose recall in schizophrenia.
Many cortical disorders are associated with memory problems. In schizophrenia, verbal memory deficits are a hallmark feature. However, the exact nature of this deficit remains elusive. Modeling aspects of language features used in memory recall have the potential to provide means for measuring these verbal processes. We employ computational language approaches to assess time-varying semantic and sequential properties of prose recall at various retrieval intervals (immediate, 30 min and 24 h later) in patients with schizophrenia, unaffected siblings and healthy unrelated control participants. First, we model the recall data to quantify the degradation of performance with increasing retrieval interval and the effect of diagnosis (i.e., group membership) on performance. Next we model the human scoring of recall performance using an n-gram language sequence technique, and then with a semantic feature based on Latent Semantic Analysis. These models show that automated analyses of the recalls can produce scores that accurately mimic human scoring. The final analysis addresses the validity of this approach by ascertaining the ability to predict group membership from models built on the two classes of language features. Taken individually, the semantic feature is most predictive, while a model combining the features improves accuracy of group membership prediction slightly above the semantic feature alone as well as over the human rating approach. We discuss the implications for cognitive neuroscience of such a computational approach in exploring the mechanisms of prose recall.
Pearson Knowledge Technologies, Boulder, CO, USA. Electronic address: mark.rosenstein@pearson.com.
Mark
M
Rosenstein
Clinical Brain Disorders Branch, National Institute of Mental Health/NIH, Bethesda, MD, USA.
Catherine
C
Diaz-Asper
Pearson Knowledge Technologies, Boulder, CO, USA; University of Colorado, Institute of Cognitive Science, Boulder, CO, USA.
Peter W
PW
Foltz
Psychiatry Research Group, Department of Clinical Medicine, University of Tromsø, Norway; Norwegian Centre for Integrated Care and Telemedicine (NST), University Hospital of North Norway, Tromsø, Norway.
Brita
B
Elvevåg
D000293:Adolescent; D000328:Adult; D016022:Case-Control Studies; D005260:Female; D020022:Genetic Predisposition to Disease; D006801:Humans; D016014:Linear Models; D016015:Logistic Models; D008297:Male; D008569:Memory Disorders / Q000235:genetics / Q000503:physiopathology* / Q000523:psychology; D061212:Memory, Episodic; D011939:Mental Recall; D008875:Middle Aged; D012559:Schizophrenia / Q000235:genetics / Q000503:physiopathology*; D012564:Schizophrenic Language; D012565:Schizophrenic Psychology; D012660:Semantics; D035781:Siblings; D055815:Young Adult
Episodic memory; Latent semantic analysis; Text analysis; Wechsler memory scale