Intellectual functioning and memory deficits in schizophrenia

Is conceptual implicit memory impaired in schizophrenia? Evidence from lexical decision and category verification

“…As mentioned in the Introduction, Ruiz et al (2007) and Soler et al (2007) found that repetition priming in schizophrenic patients was comparable to that of healthy controls in the word-fragment completion task, but significantly reduced in the category exemplar generation task. These findings suggest that schizophrenia may be associated with a specific deficit in conceptually driven implicit memory.…”

“…However, besides the perceptual/ conceptual distinction, the aforementioned tasks also differ in the involvement of identification/production processes. Word-fragment completion is primarily based on identification processes because in most studies (including those by Ruiz et al, 2007, andSoler et al, 2007), the to-be-solved fragments have unique solutions, implying small or no competition during the retrieval phase (Spataro et al, 2010). In contrast, the category generation task is heavily based on production processes (Gabrieli et al, 1999;Vaidya et al, 1997) because participants are instructed to produce the first instances that come to mind in response to a category label: in these conditions, the encoded exemplars must be selected among multiple competing responses.…”

Behavioural and neurochemical effects of post-weaning social isolation in rodents—Relevance to developmental neuropsychiatric disorders

“…The Wisconsin Card Sort Test measures this in humans, and schizophrenics have been shown to be particularly impaired in this paradigm (Bozikas et al, 2006;Elliott et al, 1995;Haut et al, 1996;Ruiz et al, 2007). A rodent version of this task has been developed (Birrell and Brown, 2000) in which food deprived rats dig in scented bowls for food rewards hidden in different digging mediums.…”

Memory Deficits in Schizophrenia: A Selective Review of Functional Magnetic Resonance Imaging (fMRI) Studies

“…Much of the empirical evidence comes from studies contrasting different memory systems in patients with schizophrenia to those of healthy controls [40], with an apparent pattern of working memory and episodic memory impairment, but less disruption of verbal short-term memory and procedural memory is seen in schizophrenia [41,42]. …”