This is a study of the functional and neuroanatomical architecture of language processes based on the reversible impairments produced by direct electrical cortical stimulation. Current neuropsychologic and neuroanatomic models all posit that language abilities are mediated by smaller, distinct processing components with specific interconnections. Some of these models specify the neuroanatomic loci of these components. The bulk of their evidence has been derived from studies of patients with fixed lesions and stable language impairments. However, this source has been part of the reason why these models have proven to be difficult to test adequately: Accidentally placed, relatively large, irreversible lesions make it difficult to fractionate the deficits that are actually present, or the true role that is played by those functions that remain. Direct, focal, electrical cortical stimulation has demonstrated the potential for overcoming some of these difficulties by being able to induce multiple, selective impairments of functions with complete reversibility. Accordingly, we will investigate the structure of reading, visual confrontation naming, and auditory comprehension through stimulation-induced deficits. Studies of static deficits on these tasks have proven to be very productive despite their limitations, and therefore should be particularly informative when deficits can be induced reversibly, and when different patterns of deficits can be produced in the same subject at different sites. Subjects will be patients with subdural electrode arrays implanted over the peri-Sylvian language regions, for clinical localization purposes prior to cortical resection for epilepsy or tumor. The first part of this study will seek to determine the nature of the deficit caused by stimulation, and establish optimal stimulation parameters. The second part will be single case studies of deficits found on clinical testing, to establish: (1) what components subserving task performance are impaired, (2) how these components are interrelated and (3) whether these relationships are the ones predicted by current theory or whether alternative representational or processing models are necessary. The third part of this proposal will relate the data on component impairments at specific cortical stimulation sites to cortical maps, by patient and by patient group. These data will therefore make a unique contribution to scientific and medical knowledge of language processes and of their cortical representations.

Agency
National Institute of Health (NIH)
Institute
National Institute of Neurological Disorders and Stroke (NINDS)
Type
Research Project (R01)
Project #
5R01NS026553-03
Application #
3412480
Study Section
Sensory Disorders and Language Study Section (CMS)
Project Start
1989-04-01
Project End
1994-03-31
Budget Start
1991-04-01
Budget End
1992-03-31
Support Year
3
Fiscal Year
1991
Total Cost
Indirect Cost
Name
Johns Hopkins University
Department
Type
Schools of Medicine
DUNS #
045911138
City
Baltimore
State
MD
Country
United States
Zip Code
21218
Ledoux, Kerry; Gordon, Barry (2011) Disruption of spelling-to-sound correspondence mapping during single-word reading in patients with temporal lobe epilepsy. Brain Lang 118:1-8
Sinai, Alon; Bowers, Christopher W; Crainiceanu, Ciprian M et al. (2005) Electrocorticographic high gamma activity versus electrical cortical stimulation mapping of naming. Brain 128:1556-70
Crone, N E; Boatman, D; Gordon, B et al. (2001) Induced electrocorticographic gamma activity during auditory perception. Brazier Award-winning article, 2001. Clin Neurophysiol 112:565-82
Hart Jr, J; Kraut, M A; Kremen, S et al. (2000) Neural substrates of orthographic lexical access as demonstrated by functional brain imaging. Neuropsychiatry Neuropsychol Behav Neurol 13:7-Jan
Lesser, R P; Kim, S H; Beyderman, L et al. (1999) Brief bursts of pulse stimulation terminate afterdischarges caused by cortical stimulation. Neurology 53:2073-81
Hart Jr, J; Crone, N E; Lesser, R P et al. (1998) Temporal dynamics of verbal object comprehension. Proc Natl Acad Sci U S A 95:6498-503
Lesser, R P; Arroyo, S; Crone, N et al. (1998) Motor and sensory mapping of the frontal and occipital lobes. Epilepsia 39 Suppl 4:S69-80
Crone, N E; Miglioretti, D L; Gordon, B et al. (1998) Functional mapping of human sensorimotor cortex with electrocorticographic spectral analysis. I. Alpha and beta event-related desynchronization. Brain 121 ( Pt 12):2271-99
Crone, N E; Miglioretti, D L; Gordon, B et al. (1998) Functional mapping of human sensorimotor cortex with electrocorticographic spectral analysis. II. Event-related synchronization in the gamma band. Brain 121 ( Pt 12):2301-15
Boatman, D; Hart Jr, J; Lesser, R P et al. (1998) Right hemisphere speech perception revealed by amobarbital injection and electrical interference. Neurology 51:458-64

Showing the most recent 10 out of 31 publications