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The Journal of Neuroscience, July 23, 2008, 28(30):7492-7500; doi:10.1523/JNEUROSCI.1852-08.2008
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Neurobiology of Disease
Magnocellular Pathway Impairment in Schizophrenia: Evidence from Functional Magnetic Resonance Imaging
Antígona Martínez,1,2 Steven A. Hillyard,2 Elisa C. Dias,1 Donald J. Hagler Jr,2 Pamela D. Butler,1 David N. Guilfoyle,1 Maria Jalbrzikowski,1 Gail Silipo,1 andDaniel C. Javitt1 1Nathan S. Kline Institute for Psychiatric Research, Orangeburg, New York 10962, and 2University of California, San Diego, La Jolla, California 92093
Correspondence should be addressed to Dr. Antígona Martínez, Nathan S. Kline Institute for Psychiatric Research, 140 Old Orangeburg Road, Orangeburg, NY 10962. Email: martinez{at}nki.rfmh.org
Sensory processing deficits in schizophrenia have been documented for several decades, but their underlying neurophysiological substrates are still poorly understood. In the visual system, the pattern of pathophysiology reported in several studies is suggestive of dysfunction within the magnocellular visual pathway beginning in early sensory cortex or even subcortically. The present study used functional magnetic resonance imaging to investigate further the neurophysiological bases of visual processing deficits in schizophrenia and in particular the potential role of magnocellular stream dysfunction. Sinusoidal gratings systematically varying in spatial frequency content were presented to subjects at low and high levels of contrast to differentially bias activity in magnocellular and parvocellular pathways based on well established differences in neuronal response profiles. Hemodynamic responses elicited by different spatial frequencies were mapped over the occipital lobe and then over the entire brain. Retinotopic mapping was used to localize the occipital activations with respect to the boundaries of visual areas V1 and V2, which were demarcated in each subject. Relative to control subjects, schizophrenia patients showed markedly reduced activations to low, but not high, spatial frequencies in multiple regions of the occipital, parietal, and temporal lobes. These findings support the hypothesis that schizophrenia is associated with impaired functioning of the magnocellular visual pathway and further suggest that these sensory processing deficits may contribute to higher-order cognitive deficits in working memory, executive functioning, and attention.
Key words: schizophrenia; spatial frequency; fMRI; magnocellular; visual processing; retinotopy
Received March 2, 2008; revised June 9, 2008; accepted June 11, 2008.
Correspondence should be addressed to Dr. Antígona Martínez, Nathan S. Kline Institute for Psychiatric Research, 140 Old Orangeburg Road, Orangeburg, NY 10962. Email: martinez{at}nki.rfmh.org
eLetters:
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- Spatial frequency and magnocellular sensitivity in schizophrenia
- John R Skoyles, et al.
- J. Neurosci. Online, 6 Aug 2008 [Full text]
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