Increased regional cerebral blood flow in inferior occipital cortex and cerebellum of early blind humans

Uhl, F.; Franzen, P.; Podreka, I.; Steiner, Manuel; Deecke, Lüder

doi:10.1016/0304-3940(93)90526-q

Cited by 89 publications

(39 citation statements)

References 7 publications

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“…This finding of an unselective response component is consistent with positron emission tomography studies showing that although early-blind subjects exhibit similar oxygen-to-glucose metabolic ratios as sighted subjects (De Volder et al 1997), primary and extrastriate visual cortical areas exhibit greater levels of glucose metabolism and regional cerebral blood flow than sighted subjects both while performing auditory or tactile tasks, and even during rest (De Volder et al 1997;Uhl et al 1993;Veraart et al 1990;Wanet-Defalque et al 1988). It is not clear what, if any, relationship there is between these nonselective enhancements of BOLD responses and superior tactile/auditory skills in early-blind individuals, given that skill enhancements as a result of early blindness have tended to be relatively specific in nature Lessard et al 1998;Roder et al 1999;Sterr et al 1998;Van Boven et al 2000).…”

Section: Discussionsupporting

confidence: 75%

Mechanisms of Cross-Modal Plasticity in Early-Blind Subjects

Lewis

Sàenz

Fine

2010

Journal of Neurophysiology

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Lewis LB, Saenz M, Fine I. Mechanisms of cross-modal plasticity in early-blind subjects. J Neurophysiol 104: 2995-3008, 2010. First published July 28, 2010 doi:10.1152/jn.00983.2009. A variety of studies have demonstrated enhanced blood oxygenation level dependent responses to auditory and tactile stimuli within occipital cortex as a result of early blindness. However, little is known about the organizational principles that drive this cross-modal plasticity. We compared BOLD responses to a wide variety of auditory and tactile tasks (vs. rest) in early-blind and sighted subjects. As expected, cross-modal responses were larger in blind than in sighted subjects in occipital cortex for all tasks (cross-modal plasticity). Within both blind and sighted subject groups, we found patterns of cross-modal activity that were remarkably similar across tasks: a large proportion of cross-modal responses within occipital cortex are neither task nor stimulus specific. We next examined the mechanisms underlying enhanced BOLD responses within early-blind subjects. We found that the enhancement of cross-modal responses due to early blindness was best described as an additive shift, suggesting that cross-modal plasticity within blind subjects does not originate from either a scaling or unmasking of cross-modal responsivities found in sighted subjects.

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Section: Discussionsupporting

confidence: 75%

Mechanisms of Cross-Modal Plasticity in Early-Blind Subjects

Lewis

Sàenz

Fine

2010

Journal of Neurophysiology

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“…Studies measuring metabolic viability using single-photon emission computed tomography, fluorodeoxyglucose positron emission tomography (PET), and 15 O-PET have revealed that the occipital cortical tissue of early blind subjects is hypermetabolic compared with that of sighted subjects [Uhl et al, 1993;Veraart et al, 1990;Wanet-Defalque et al, 1988]. A striking result with respect to occipital cortex function in blind subjects was recently presented by , who observed increased regional cerebral blood flow in the primary visual cortex when blind subjects read Braille compared with passively presented tactile control conditions.…”

Section: Introductionmentioning

confidence: 93%

Sensory mapping in a congenitally deaf subject: MEG and fRMI studies of cross-modal non-plasticity

et al. 1997

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It has been proposed that the auditory cortex of deaf subjects may provide an example of cross-modal compensatory plasticity. We investigated whether sensory stimulation could elicit responses from auditory areas of a congenitally deaf subject. Neuromagnetic fields were recorded using a 37-channel biomagnetometer under conditions of: 1) visual stimulation; 2) somatosensory stimulation; and 3) a simple motor task. Visual items were reversing checkerboards and single light spots, presented in various portions of the visual field; somatosensory stimuli were pneumatic taps delivered to individual digit-segments and the lip; the motor task was self-paced finger tapping. In addition, functional magnetic resonance imaging was used to observe the activation elicited by full-field checkerboard and sign language stimuli. No responses to passively presented visual or somatosensory stimuli were observed in the auditory cortex. In contrast, somatosensory, motor, and visual cortices revealed evoked magnetic responses comparable to those from control subjects, indicating canonical anatomic and physiological organization in these areas. These data suggest that primary projection areas do not reveal obvious plastic effects. We suggest that in the human auditory cortex compensatory plasticity emerges primarily as a property of non-primary areas and is best observed under attentionally demanding conditions.

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“…Plasticity has also been observed throughout the auditory pathway of both visually deprived animals [12,14,25,28] and early blind humans [6,17,26,36]. While these studies elucidate some heightened auditory skills in blind individuals (e.g., enhanced spatial localization), relatively few paradigms have examined auditory processing as compared to somatosensory or visual systems.…”

Section: Introductionmentioning

confidence: 99%

Cortical plasticity in an early blind musician: an fMRl study

Ross

Olson

Gore

2003

Magnetic Resonance Imaging

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Many studies have examined tactile perception and simple auditory perception in the blind, but none have previously investigated the neural basis of musical ability in this group. This topic is of particular interest because it has been suggested that early blind individuals may possess advanced musical skills (such as absolute pitch). Presumably, these skills could be the result of neural plasticity. It has been hard to empirically assess this claim because of the difficulty in recruiting an adequate number of subjects for use in a conventional paradigm. In the present paper, we report data from a congenitally blind musician, subject ML. Behavioral tests show that she possessed absolute pitch abilities that were similar to those of a reference group of AP musicians with normal vision. To examine the neural basis of her abilities we then tested subject ML and five control subjects using an fMRI paradigm. A regions-of-interest analysis found that similar areas (the right secondary auditory cortex, left IFG, left SMG) were activated in ML and the control subjects, to a similar degree, in response to music processing. However, ML showed additional activations in left parietal association cortices and extrastriate regions of the occipital lobe. Subject ML's data are consistent with a vast body of literature on blindness-induced plasticity. They extend these findings by demonstrating that cortical plasticity may underlie special musical skills as well. These data illustrate the potential value of case studies to investigate particularly rare phenotypes.

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Increased regional cerebral blood flow in inferior occipital cortex and cerebellum of early blind humans

Cited by 89 publications

References 7 publications

Mechanisms of Cross-Modal Plasticity in Early-Blind Subjects

Mechanisms of Cross-Modal Plasticity in Early-Blind Subjects

Sensory mapping in a congenitally deaf subject: MEG and fRMI studies of cross-modal non-plasticity

Cortical plasticity in an early blind musician: an fMRl study

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