title: How does the hippocampal formation mediate memory for stimuli processed by the magnocellular and parvocellular visual pathways? Evidence from the comparison of schizophrenia and amnestic mild cognitive impairment (aMCI).
abstract: Paired associates learning is impaired in both schizophrenia and amnestic mild cognitive impairment (aMCI), which may reflect hippocampal pathology. In addition, schizophrenia is characterized by the dysfunction of the retino-geniculo-striatal magnocellular (M) visual pathway. The purpose of this study was to investigate the interaction between visual perceptual and memory dysfunctions. We administered a modified version of the CANTAB paired associates learning task to patients with schizophrenia (n=20), aMCI (n=20), and two groups of matched healthy controls (n=20 for each patient group). The stimuli in the paired associates learning task biased information processing toward the M pathways (low contrast, low spatial frequency) and parvocellular (P) pathways (high contrast, high spatial frequency). Results revealed that patients with schizophrenia exhibited a more pronounced learning deficit for M-biased relative to P-biased stimuli. In aMCI, there were similar memory deficits for both types of stimuli. Orientation discrimination for M- and P-biased stimuli was intact in both groups of patients. The number of errors in the M-biased memory condition significantly and inversely correlated with the volume of the right hippocampus in schizophrenia. These results suggest an interaction between M-biased perceptual processing and short-term relational memory in schizophrenia, which may be associated with the structural alteration of the right hippocampus.
authors.affiliation: National Psychiatry Center, Budapest, Hungary; University of Szeged, Faculty of Medicine, Department of Physiology, Dom sq 10, Szeged, Hungary. szkeri2000@yahoo.com
authors.forename: Szabolcs
authors.initials: S
authors.lastname: Kéri
authors.forename: András
authors.initials: A
authors.lastname: Szamosi
authors.forename: György
authors.initials: G
authors.lastname: Benedek
authors.forename: Oguz
authors.initials: O
authors.lastname: Kelemen
mesh_terms: D000328:Adult; D000368:Aged; D000704:Analysis of Variance; D001245:Association Learning / Q000502:physiology; D016022:Case-Control Studies; D060825:Cognitive Dysfunction / Q000150:complications* / Q000473:pathology; D004192:Discrimination, Psychological / Q000502:physiology; D005260:Female; D007839:Functional Laterality; D006624:Hippocampus / Q000503:physiopathology*; D006801:Humans; D007091:Image Processing, Computer-Assisted; D016014:Linear Models; D008279:Magnetic Resonance Imaging; D008297:Male; D008569:Memory Disorders / Q000209:etiology* / Q000473:pathology*; D008875:Middle Aged; D009483:Neuropsychological Tests; D009949:Orientation / Q000502:physiology; D010775:Photic Stimulation; D012559:Schizophrenia / Q000150:complications* / Q000473:pathology; D014795:Visual Pathways / Q000503:physiopathology*