Facilitation of relational learning in schizophrenia.

Abnormal hippocampal function likely contributes to relational learning deficits observed in schizophrenia. It is unknown whether these deficits can be attenuated with a training intervention. The purpose of this project was to determine if training could facilitate relational learning of the transverse patterning task in schizophrenia.

Neural correlates of the relationship between discourse coherence and sensory monitoring in schizophrenia.

Unusual language use is a core feature of psychosis, but the nature and significance of this are not understood. In particular, thought disorder in schizophrenia (SZ) is characterized by markedly bizarre speech, but the cognitive components that contribute to this and the brain correlates of these components are unknown. A number of studies have demonstrated language abnormalities in single word processing, but few have examined speech in SZ at the discourse level.

Spatial memory deficits in a virtual reality eight-arm radial maze in schizophrenia.

Learning and memory impairments are present in schizophrenia (SZ) throughout the illness course and predict psychosocial function. Abnormalities in prefrontal and hippocampal function are thought to contribute to SZ deficits. The radial arm maze (RAM) is a test of spatial learning and memory in rodents that relies on intact prefrontal and hippocampal function.

Repetition of letter strings leads to activation of and connectivity with word-related regions.

Individuals learn to read by gradually recognizing repeated letter combinations. However, it is unclear how or when neural mechanisms associated with repetition of basic stimuli (i.e.

Neural changes associated with relational learning in schizophrenia.

Relational learning, which is learning the relationship among items, is impaired in schizophrenia but can be improved with training. This study investigated neural changes with functional magnetic resonance imaging before and after training on a relational learning task in schizophrenia and healthy control subjects. Despite their acquiring similar relational learning performance, the groups exhibited different neural activation patterns before and following training.

Predicting transfer performance: a comparison of competing function learning models.

The population of linear experts (POLE) model suggests that function learning and transfer are mediated by activation of a set of prestored linear functions that together approximate the given function (Kalish, Lewandowsky, & Kruschke, 2004). In the extrapolation-association (EXAM) model, an exemplar-based architecture associates trained input values with their paired output values. Transfer incorporates a linear rule-based response mechanism (McDaniel & Busemeyer, 2005).

Word and letter string processing networks in schizophrenia: evidence for anomalies and compensation.

Imaging studies show that in normal language correlated activity between anterior and posterior brain regions increases as the linguistic and semantic content (i.e., from false fonts, letter strings, pseudo words, to words) of stimuli increase.

Adult age differences in function concept learning.

Function concept learning and knowledge use was explored across adulthood. During training older and younger adults predicted an amount of physiological arousal produced as a negative and positive function of a chemical substance. Knowledge use was evaluated with two transfer conditions requiring a switch between contextual contingencies: a relationship inversion, predicting the chemical amount given the physiological arousal, and a change from graphic based to text based stimuli.

Proton magnetic resonance spectroscopy of the hippocampus and occipital white matter in PTSD: preliminary results.

Objective: Previous proton magnetic resonance spectroscopy (1H-MRS) studies in posttraumatic stress disorder (PTSD) report decreased hippocampal N-acetylaspartate (NAA), an indicator of neuronal integrity. However, other areas of the brain need to be explored. The objective of this study was to investigate the specificity of hippocampal NAA concentration changes in PTSD by also examining a control region, the occipital white matter (OWM).