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bilateral scalp positions, but the percentage of the motoneuron pool activated by scalp stimulation is larger in patients 13. Similar results have been described after quadriplegia 11, and are compatible with the development of enlarged maps of outputs with lower thresholds of excitation for muscles proximal to the lesion following spinal cord injury. Stimulation of one side of the scalp can elicit bilateral muscle responses in patients who have undergone resection of one hemisphere for treatment of intractable epilepsy 16'17. Focal transcranial magnetic stimulation can produce separate representations of both ipsilateral and contralateral muscles in the remaining hemisphere, indicating the existence of reorganization of motor pathways following large brain lesions 16. Similar findings can be obtained with positron emission tomography (PET) and topographic mapping of premotor potentials ~6. Finally, the sensorimotor representation of the reading finger of blind, proficient braille readers has been studied using transcranial magnetic stimulation and SSEPs18. Compared with the results obtained from the nonreading fingers and the same fingers of controls, detection of an electric stimulus applied to the reading fingers can be blocked by transcranial magnetic stimulation delivered over a larger contralateral scalp area and during a longer time window. In addition, topographic SSEP mapping demonstrates a larger area of peak amplitude for several cortical components of the potentials evoked from the reading fingers. These results suggest that reading braille is associated with expansion of the sensorimotor cortical representation of the reading finger.
References 1 Asanuma, C. (1991) Trends Neurosci. 14, 217-218 2 Kaas,J. H. (1991) Annu. Rev. Neurosci. 14, 137-167 3 Merton, P. A. and Morton, H. B. (1980) Nature 285, 227 4 Barker,A. T., Jalinous,R. and Freeston, I. L (1985) Lancet i, 1106-1107 5 Cohen, L. G. (1991) J. Clin. Neurophysiol. 8, 56-65 14
14 Farmer,.S. F. et aL (1990) J. Physiol. 428, 467-484 15 Cohen, L. G. etaL (1991) Brain 114, 381-403 Hallett, M. and Cohen, L. G. Electroenceph. Clin. Neurophysiol. (in press) 16 Cohen, L. G. et al. (1991)J. Physiol. (in press) Hess, C. W., Mills, K. R. and Murray, N. M. F. (1986) Neurosci. Lett. 71, 17 Benecke, R., Meyer, B-U. and Freund, H-J. Exp. Brain Res. (in press) 235-240 Cohen, L. G., Bandinelli, S., Findley, 18 PascuaI-Leone,A. and Torres, F. Brain (in press) T. W. and Hallett, M. (1991) Brain 19 Sica, R. E. P., Sanz, O. P., Cohen, 114, 615-627 L. G., Freyre, J. D. and Panizza, M. Fuhr, P., Cohen, L. G., Findley, T. W., Electromyograph. Clin. NeurophysioL Macedo, J. and Hallett, M. Electro24, 415-427 enceph. Clin. Neurophysiol. (in press) Levy, W. J., Amassian,V. E., Traal, M. Alvaro PascuaI-Leone and Cadwell, J. (1990) Brain Res. 510, Leonardo G. Cohen 130-134 Mark Hallett Cohen, L. G., Topka, H., Cole, R. A. The Human Cortical Physiology Unit, Human and Hallett, M. (1991) Neurology 41, Motor Control Section, Medical Neurology 1283-1288 Topka, H., Cohen, L. G., Cole, R. A. Branch, National Institute of Neurological and Hallett, M. (1991) Neurology 41, Diseasesand Stroke, NIH, Bethesda,/HA 20892, USA. 1276-1283
6 Cohen, L. G. and Hallett, M. (1988) Neurology 38, 904-909 7 Wassermann, E. W., McShane, L M.,
8 9 10 11 12 13
ERRATUM In the article 'Olfaction in Drosophila: genetic and molecular analysis' by John Carlson (December 1991, Vol. 14, pp. 5 2 0 - 5 2 4 ) , Fig. 1 was incomplete. The correct version is printed below, along with its accompanying legend, and we apologize to Dr Carlson and the readers for the error.
Fig. 1. Fly head. Arrow indicates third antennal segment, covered with sensory hairs.
TINS, Vol. 15, No. 1, 1992
letters
to the
editor
bilateral scalp positions, but the percentage of the motoneuron pool activated by scalp stimulation is larger in patients 13. Similar results have been described after quadriplegia 11, and are compatible with the development of enlarged maps of outputs with lower thresholds of excitation for muscles proximal to the lesion following spinal cord injury. Stimulation of one side of the scalp can elicit bilateral muscle responses in patients who have undergone resection of one hemisphere for treatment of intractable epilepsy 16'17. Focal transcranial magnetic stimulation can produce separate representations of both ipsilateral and contralateral muscles in the remaining hemisphere, indicating the existence of reorganization of motor pathways following large brain lesions 16. Similar findings can be obtained with positron emission tomography (PET) and topographic mapping of premotor potentials ~6. Finally, the sensorimotor representation of the reading finger of blind, proficient braille readers has been studied using transcranial magnetic stimulation and SSEPs18. Compared with the results obtained from the nonreading fingers and the same fingers of controls, detection of an electric stimulus applied to the reading fingers can be blocked by transcranial magnetic stimulation delivered over a larger contralateral scalp area and during a longer time window. In addition, topographic SSEP mapping demonstrates a larger area of peak amplitude for several cortical components of the potentials evoked from the reading fingers. These results suggest that reading braille is associated with expansion of the sensorimotor cortical representation of the reading finger.
References 1 Asanuma, C. (1991) Trends Neurosci. 14, 217-218 2 Kaas,J. H. (1991) Annu. Rev. Neurosci. 14, 137-167 3 Merton, P. A. and Morton, H. B. (1980) Nature 285, 227 4 Barker,A. T., Jalinous,R. and Freeston, I. L (1985) Lancet i, 1106-1107 5 Cohen, L. G. (1991) J. Clin. Neurophysiol. 8, 56-65 14
14 Farmer,.S. F. et aL (1990) J. Physiol. 428, 467-484 15 Cohen, L. G. etaL (1991) Brain 114, 381-403 Hallett, M. and Cohen, L. G. Electroenceph. Clin. Neurophysiol. (in press) 16 Cohen, L. G. et al. (1991)J. Physiol. (in press) Hess, C. W., Mills, K. R. and Murray, N. M. F. (1986) Neurosci. Lett. 71, 17 Benecke, R., Meyer, B-U. and Freund, H-J. Exp. Brain Res. (in press) 235-240 Cohen, L. G., Bandinelli, S., Findley, 18 PascuaI-Leone,A. and Torres, F. Brain (in press) T. W. and Hallett, M. (1991) Brain 19 Sica, R. E. P., Sanz, O. P., Cohen, 114, 615-627 L. G., Freyre, J. D. and Panizza, M. Fuhr, P., Cohen, L. G., Findley, T. W., Electromyograph. Clin. NeurophysioL Macedo, J. and Hallett, M. Electro24, 415-427 enceph. Clin. Neurophysiol. (in press) Levy, W. J., Amassian,V. E., Traal, M. Alvaro PascuaI-Leone and Cadwell, J. (1990) Brain Res. 510, Leonardo G. Cohen 130-134 Mark Hallett Cohen, L. G., Topka, H., Cole, R. A. The Human Cortical Physiology Unit, Human and Hallett, M. (1991) Neurology 41, Motor Control Section, Medical Neurology 1283-1288 Topka, H., Cohen, L. G., Cole, R. A. Branch, National Institute of Neurological and Hallett, M. (1991) Neurology 41, Diseasesand Stroke, NIH, Bethesda,/HA 20892, USA. 1276-1283
6 Cohen, L. G. and Hallett, M. (1988) Neurology 38, 904-909 7 Wassermann, E. W., McShane, L M.,
8 9 10 11 12 13
ERRATUM In the article 'Olfaction in Drosophila: genetic and molecular analysis' by John Carlson (December 1991, Vol. 14, pp. 5 2 0 - 5 2 4 ) , Fig. 1 was incomplete. The correct version is printed below, along with its accompanying legend, and we apologize to Dr Carlson and the readers for the error.
Fig. 1. Fly head. Arrow indicates third antennal segment, covered with sensory hairs.
TINS, Vol. 15, No. 1, 1992
to the
editor
bilateral scalp positions, but the percentage of the motoneuron pool activated by scalp stimulation is larger in patients 13. Similar results have been described after quadriplegia 11, and are compatible with the development of enlarged maps of outputs with lower thresholds of excitation for muscles proximal to the lesion following spinal cord injury. Stimulation of one side of the scalp can elicit bilateral muscle responses in patients who have undergone resection of one hemisphere for treatment of intractable epilepsy 16'17. Focal transcranial magnetic stimulation can produce separate representations of both ipsilateral and contralateral muscles in the remaining hemisphere, indicating the existence of reorganization of motor pathways following large brain lesions 16. Similar findings can be obtained with positron emission tomography (PET) and topographic mapping of premotor potentials ~6. Finally, the sensorimotor representation of the reading finger of blind, proficient braille readers has been studied using transcranial magnetic stimulation and SSEPs18. Compared with the results obtained from the nonreading fingers and the same fingers of controls, detection of an electric stimulus applied to the reading fingers can be blocked by transcranial magnetic stimulation delivered over a larger contralateral scalp area and during a longer time window. In addition, topographic SSEP mapping demonstrates a larger area of peak amplitude for several cortical components of the potentials evoked from the reading fingers. These results suggest that reading braille is associated with expansion of the sensorimotor cortical representation of the reading finger.
References 1 Asanuma, C. (1991) Trends Neurosci. 14, 217-218 2 Kaas,J. H. (1991) Annu. Rev. Neurosci. 14, 137-167 3 Merton, P. A. and Morton, H. B. (1980) Nature 285, 227 4 Barker,A. T., Jalinous,R. and Freeston, I. L (1985) Lancet i, 1106-1107 5 Cohen, L. G. (1991) J. Clin. Neurophysiol. 8, 56-65 14
14 Farmer,.S. F. et aL (1990) J. Physiol. 428, 467-484 15 Cohen, L. G. etaL (1991) Brain 114, 381-403 Hallett, M. and Cohen, L. G. Electroenceph. Clin. Neurophysiol. (in press) 16 Cohen, L. G. et al. (1991)J. Physiol. (in press) Hess, C. W., Mills, K. R. and Murray, N. M. F. (1986) Neurosci. Lett. 71, 17 Benecke, R., Meyer, B-U. and Freund, H-J. Exp. Brain Res. (in press) 235-240 Cohen, L. G., Bandinelli, S., Findley, 18 PascuaI-Leone,A. and Torres, F. Brain (in press) T. W. and Hallett, M. (1991) Brain 19 Sica, R. E. P., Sanz, O. P., Cohen, 114, 615-627 L. G., Freyre, J. D. and Panizza, M. Fuhr, P., Cohen, L. G., Findley, T. W., Electromyograph. Clin. NeurophysioL Macedo, J. and Hallett, M. Electro24, 415-427 enceph. Clin. Neurophysiol. (in press) Levy, W. J., Amassian,V. E., Traal, M. Alvaro PascuaI-Leone and Cadwell, J. (1990) Brain Res. 510, Leonardo G. Cohen 130-134 Mark Hallett Cohen, L. G., Topka, H., Cole, R. A. The Human Cortical Physiology Unit, Human and Hallett, M. (1991) Neurology 41, Motor Control Section, Medical Neurology 1283-1288 Topka, H., Cohen, L. G., Cole, R. A. Branch, National Institute of Neurological and Hallett, M. (1991) Neurology 41, Diseasesand Stroke, NIH, Bethesda,/HA 20892, USA. 1276-1283
6 Cohen, L. G. and Hallett, M. (1988) Neurology 38, 904-909 7 Wassermann, E. W., McShane, L M.,
8 9 10 11 12 13
ERRATUM In the article 'Olfaction in Drosophila: genetic and molecular analysis' by John Carlson (December 1991, Vol. 14, pp. 5 2 0 - 5 2 4 ) , Fig. 1 was incomplete. The correct version is printed below, along with its accompanying legend, and we apologize to Dr Carlson and the readers for the error.
Fig. 1. Fly head. Arrow indicates third antennal segment, covered with sensory hairs.
TINS, Vol. 15, No. 1, 1992
letters
to the
editor
bilateral scalp positions, but the percentage of the motoneuron pool activated by scalp stimulation is larger in patients 13. Similar results have been described after quadriplegia 11, and are compatible with the development of enlarged maps of outputs with lower thresholds of excitation for muscles proximal to the lesion following spinal cord injury. Stimulation of one side of the scalp can elicit bilateral muscle responses in patients who have undergone resection of one hemisphere for treatment of intractable epilepsy 16'17. Focal transcranial magnetic stimulation can produce separate representations of both ipsilateral and contralateral muscles in the remaining hemisphere, indicating the existence of reorganization of motor pathways following large brain lesions 16. Similar findings can be obtained with positron emission tomography (PET) and topographic mapping of premotor potentials ~6. Finally, the sensorimotor representation of the reading finger of blind, proficient braille readers has been studied using transcranial magnetic stimulation and SSEPs18. Compared with the results obtained from the nonreading fingers and the same fingers of controls, detection of an electric stimulus applied to the reading fingers can be blocked by transcranial magnetic stimulation delivered over a larger contralateral scalp area and during a longer time window. In addition, topographic SSEP mapping demonstrates a larger area of peak amplitude for several cortical components of the potentials evoked from the reading fingers. These results suggest that reading braille is associated with expansion of the sensorimotor cortical representation of the reading finger.
References 1 Asanuma, C. (1991) Trends Neurosci. 14, 217-218 2 Kaas,J. H. (1991) Annu. Rev. Neurosci. 14, 137-167 3 Merton, P. A. and Morton, H. B. (1980) Nature 285, 227 4 Barker,A. T., Jalinous,R. and Freeston, I. L (1985) Lancet i, 1106-1107 5 Cohen, L. G. (1991) J. Clin. Neurophysiol. 8, 56-65 14
14 Farmer,.S. F. et aL (1990) J. Physiol. 428, 467-484 15 Cohen, L. G. etaL (1991) Brain 114, 381-403 Hallett, M. and Cohen, L. G. Electroenceph. Clin. Neurophysiol. (in press) 16 Cohen, L. G. et al. (1991)J. Physiol. (in press) Hess, C. W., Mills, K. R. and Murray, N. M. F. (1986) Neurosci. Lett. 71, 17 Benecke, R., Meyer, B-U. and Freund, H-J. Exp. Brain Res. (in press) 235-240 Cohen, L. G., Bandinelli, S., Findley, 18 PascuaI-Leone,A. and Torres, F. Brain (in press) T. W. and Hallett, M. (1991) Brain 19 Sica, R. E. P., Sanz, O. P., Cohen, 114, 615-627 L. G., Freyre, J. D. and Panizza, M. Fuhr, P., Cohen, L. G., Findley, T. W., Electromyograph. Clin. NeurophysioL Macedo, J. and Hallett, M. Electro24, 415-427 enceph. Clin. Neurophysiol. (in press) Levy, W. J., Amassian,V. E., Traal, M. Alvaro PascuaI-Leone and Cadwell, J. (1990) Brain Res. 510, Leonardo G. Cohen 130-134 Mark Hallett Cohen, L. G., Topka, H., Cole, R. A. The Human Cortical Physiology Unit, Human and Hallett, M. (1991) Neurology 41, Motor Control Section, Medical Neurology 1283-1288 Topka, H., Cohen, L. G., Cole, R. A. Branch, National Institute of Neurological and Hallett, M. (1991) Neurology 41, Diseasesand Stroke, NIH, Bethesda,/HA 20892, USA. 1276-1283
6 Cohen, L. G. and Hallett, M. (1988) Neurology 38, 904-909 7 Wassermann, E. W., McShane, L M.,
8 9 10 11 12 13
ERRATUM In the article 'Olfaction in Drosophila: genetic and molecular analysis' by John Carlson (December 1991, Vol. 14, pp. 5 2 0 - 5 2 4 ) , Fig. 1 was incomplete. The correct version is printed below, along with its accompanying legend, and we apologize to Dr Carlson and the readers for the error.
Fig. 1. Fly head. Arrow indicates third antennal segment, covered with sensory hairs.
TINS, Vol. 15, No. 1, 1992
