Auditory re-afferentation by cochlear implants (CI) offers a unique opportunity to study directly from within the auditory modality plastic changes taking place at organisational levels up to the supra- or polymodal level. These plastic changes resulting from deafness and chronic electrical stimulation can be studied using modern neuroimaging techniques. In this paper, we review the available techniques and the experimental approaches to human studies of plasticity, we discuss the different forms of plasticity that are associated with cochlear implantation and we point to the interest of imaging studies for providing a prognosis of functional outcome after implantation.

1.
Bavelier D, Tomann A, Hutton C, Mitchell T, Corina D, Liu G, Neville H: Visual attention to the periphery is enhanced in congenitally deaf individuals. J Neurosci 2000;20:1–6.
2.
Benedict RHB, Lockwood AH, Shucard JL, Shucard DW, Wack D, Murphy BW: Functional neuroimaging of attention in the auditory modality. Neuroreport 1998;9:121–126.
3.
Berthezène Y, Truy E, Morgon A, Giard MH, Hermier M, Franconi JM, Froment JC: Auditory cortex activation in deaf subjects during cochlear electrical stimulation: Evaluation by functional magnetic resonance imaging. Invest Radiol 1997;32:297–301.
4.
Beversdorf D, Metzger S, Nelson D, Alonso R, Kight J: Single-word auditory stimulation and regional cerebral blood flow as studied by SPECT. Psychiatry Res 1995;61:181–189.
5.
Buechel C, Coull JT, Friston KJ: The predictive value of changes in effective connectivity for human learning. Science 1999;283:1538–1541.
6.
Buffalo EA, Ramus SJ, Clark RE, Teng E, Squire LR, Zola SM: Dissociation between the effects of damage to perirhinal cortex and area TE. Learn Mem 1999;6:572–599.
7.
Capaday C, Richardson MP, Rothwell JC, Brooks DJ: Long-term changes of GABAergic function in the sensorimotor cortex of amputees: A combined magnetic stimulation and 11C-flumazenil PET study. Exp Brain Res 2000;133:552–556.
8.
Catalan-Ahumada M, Deggouj N, De Volder A, Melin J, Michel C, Veraart C: High metabolic activity demonstrated by positron emission tomography in human auditory cortex in case of deafness of early onset. Brain Res 1993;623:287–292.
9.
Coull JT, Nobre AC: Where and when to pay attention: The neural systems for directing attention to spatial locations and to time intervals as revealed by both PET and fMRI. J Neurosci 1998;18:7426–7435.
10.
Duong TQ, Kim DS, Ugurbil K, Kim SG: Spatiotemporal dynamics of the BOLD fMRI signals: Toward mapping submillimeter cortical columns using the early negative response. Magn Reson Med 2000;44:231–242.
11.
Eddington DK, Melcher JR, Qin M, Stroka J, Weisskoff RM: Electrically-evoked cortical activity in cochlear implant subjects can be mapped using functional magnetic resonance imaging (abstract 160). Abstr ARO 1999.
12.
Friston KJ, Holmes AP, Worsley KJ: How many subjects constitute a study. Neuroimage1999;10:1–5.
13.
Fujiki N, Naito Y, Hirano S, Kojima H, Kamoto Y, Nishizawa S, Konishi J, Honjo I: Influence of speech-coding strategy on cortical activity in cochlear implant users: A positron emission tomographic study. Acta Otolaryngol 1998;118:797–802.
14.
Fujiki N, Naito Y, Hirano S, Kojima H, Shiomi Y, Nishizawa S, Konishi J, Honjo I: Correlation between rCBF and speech perception in cochlear implant users. Auris Nasus Larynx 1999;26:229–236.
15.
Giard M-H, Collet L, Bouchet P, Pernier J: Auditory selective attention in the human cochlea. Hear Res 1994;33:353–356.
16.
Giraud A-L, Garnier S, Micheyl C, Lina G, Chays A, Chéry-Croze S: Auditory efferents involved in speech in noise intelligibility. Neuroreport 1997;7:1779–1783.
17.
Giraud AL, Price CJ: The constraints functional imaging palces on classical models of auditory word processing. J Cogn Neurosci 2001;13:754–765.
18.
Giraud AL, Price CJ, Graham JM, Frackowiak RSJ: Functional plasticity of language-related brain areas after cochlear implantation. Brain 2001a;124:101–110.
19.
Giraud AL, Price CJ, Graham JM, Truy E, Frackowiak RSJ: Cross-modal plasticity underpins recovery of language function after cochlear implantation. Neuron 2001b;30:657–663.
20.
Giraud AL, Truy E, Frackowiak RSJ, Grégoire MC, Pujol JF, Collet L: Differential recruitment of the speech comprehension system in healthy subjects and rehabilitated cochlear implant patients. Brain 2000;123:1391–1402.
21.
Hari R: Neuromagnetic approach to human auditory cortical functions, with emphasis on subjects with cochlear implants. Adv Otorhinolaryngol 1997;52:15–18.
22.
Herzog H, Lamprecht A, Kuhn A, Roden W, Vosteen KH, Feinendegen LE: Cortical activation in profoundly deaf patients during cochlear implant stimulation demonstrated by H2(15)O PET. J Comput Assist Tomogr 1991;15:369–375.
23.
Hofmann E, Preibisch C, Knaus C, Muller J, Kremser C, Teissl C: Non invasive direct stimulation of the cochlear nerve for functional MR imaging of the auditory cortex. AJNR Am J Neuroradiol 1999;20:1970–1972.
24.
Ito J, Sakakibara J, Iwasaki Y, Yonekura Y: Positron emission tomography of auditory sensation in deaf patients and patients with cochlear implants. Ann Otol Rhinol Laryngol 1993;102:797–801.
25.
Johnsrude IS, Giraud AL, Frackowiak RSJ: Functional imaging of the auditory system: The use of positron emission tomography. Audiol Neurootol 2002, in press.
26.
Klinke R, Kral A, Heid S, Tillein J, Hartmann R: Recruitment of the auditory cortex in congenitally deaf cats by long-term cochlear electrostimulation. Science 1999;285:1729–1733.
27.
Kral A, Hartmann R, Tillein J, Heid S, Klinke R: Delayed maturation and sensitive periods in the auditory cortex. Audiol Neurootol 2001;6:346–362.
28.
Lazeyras F, Boex C, Sigrist A, Cosendai G, Terrier F, Pellizone M: Auditory cortex activation by direct cochlear implant electrical stimulation. Neuroimage 2001;13:S905.
29.
Lee DS, Lee JS, Oh SH, Kim SK, Kim JW, Chung JK, Lee MC, Kim CS: Cross-modal plasticity and cochlear implants. Nature 2001;409:149–150.
30.
Lustig LR, Leake PA, Snyder RL, Rebscher SJ: Changes in the cat cochlear nucleus following neonatal deafening and chronic intracochlear electrical stimulation. Hear Res 1994;74:29–37.
31.
McDermott KB, Ojemann JG, Petersen SE, Ollinger JM, Snyder AZ, Akbudak E, Conturo TE, Raichle ME: Direct comparison of episodic encoding and retrieval of words: An event-related fMRI study. Memory 1999;7:661–678.
32.
McIntosh AR, Cabeza RE, Lobaugh NJ: Analysis of neural interactions explains the activation of occipital cortex by an auditory stimulus. J Neurophysiol 1998;80:2790–2796.
33.
Menon RS, Ogawa S, Strupp JP, Ugurbil K: Ocular dominance in human V1 demonstrated by functional magnetic resonance imaging. J Neurophysiol 1997;77:2780–2787.
34.
Mummery CJ, Patterson K, Hodges JR, Price CJ: Functional neuroanatomy of the semantic system: Divisible by what? J Cogn Neurosci 1998;10:766–777.
35.
Nagase S, Miller JM, Dupont J, Lim HH, Sato K, Altschuler RA: Changes in cochlear electrical stimulation induced Fos expression in the rat inferior colliculus following deafness. Hear Res 2000;147:242–250.
36.
Naito Y, Hirano S, Honjo I, Okazawa H, Ishizu K, Takahashi H, Fujiki N, Shiomi Y, Yonekura Y, Konishi J: Sound-induced activation of auditory cortices in cochlear implant users with post- and prelingual deafness demonstrated by positron emission tomography. Acta Otolaryngol 1997;117:490–496.
37.
Naito Y, Okazawa H, Honjo I, Hirano S, Takahashi H, Shiomi Y, Hoji W, Kawano M, Ishizu K, Yonekura Y: Cortical activation with sound stimulation in cochlear implant users demonstrated by positron emission tomography. Brain Res Cogn Brain Res 1995;2:207–214a.
38.
Naito Y, Okazawa H, Honjo I, Takahashi H, Kawano M, Ishizu K, Yonekura Y: Cortical activation during sound stimulation in cochlear implant users demonstrated by positron emission tomography. Ann Otol Rhinol Laryngol Suppl 1995;166:60–64b.
39.
Naito Y, Tateya I, Fujiki N, Hirano S, Ishizu K, Nagahama Y, Fukuyama H, Kojima H: Increased cortical activation during hearing of speech in cochlear implant users. Hear Res 2000;143:139–146.
40.
Neville HJ, Lawson D: Attention to central and peripheral visual space in a movement detection task: An event-related potential and behavioral study. I. Normal hearing adults. Brain Res 1987a;405:253–267.
41.
Neville HJ, Lawson D: Attention to central and peripheral visual space in a movement detection task: An event-related potential and behavioral study. II. Congenitally deaf adults. Brain Res 1987b;405:268–283.
42.
Neville HJ, Lawson D: Attention to central and peripheral visual space in a movement detection task. III. Separate effects of auditory deprivation and acquisition of a visual language. Brain Res 1987c;405:284–294.
43.
Nishimura H, Doi K, Iwaki T, Hashikawa K, Oku N, Teratani T, Hasegawa T, Watanabe A, Nishimura T, Kubo T: Neural plasticity detected in short- and long-term cochlear implant users using PET. Neuroreport 2000;11:811–815.
44.
Nishimura H, Hashikawa K, Doi K, Iwaki T, Watanabe Y, Kusuoka H, Nishimura T, Kubo T: Sign language ‘heard’ in the auditory cortex. Nature 1999;397:116.
45.
Obler R, Kostler H, Weber BP, Mack KF, Becker H: Safe electrical stimulation of the cochlear nerve at the promontory during functional magnetic resonance imaging. Magn Reson Med 1999;42:371–378.
46.
Okazawa H, Naito Y, Yonekura Y, Sadato N, Hirano S, Nishizawa S, Magata Y, Ishizu K, Tamaki N, Honjo I, Konishi J: Cochlear implant efficiency in pre- and postlingually deaf subjects: A study with H2(15)O and PET. Brain 1996;119:1297–1306.
47.
O’Leary DS, Andreason NC, Hurtig RR, Hishwa RD, Watkins GL, Ponton LL, Rogers M, Kirchner PT: A positron emission tomography study of binaurally and dichotically presented stimuli: Effects of language and directed attention. Brain Lang 1996;53:20–39.
48.
Pelizzone M, Kasper A, Hari R, Karhu J, Montandon P: Bilateral electrical stimulation of a congenitally-deaf ear and of an acquired-deaf ear. Acta Otolaryngol 1991;111:263–268.
49.
Petitto LA, Zatorre RJ, Gauna K, Nikelski EJ, Dostie D, Evans AC: Speech-like cerebral activity in profoundly deaf people processing signed languages: Implications for the neural basis of human language. Proc Natl Acad Sci USA 2000;95:13961–13966.
50.
Poldrack RA: Imaging brain plasticity: Conceptual and methodological issues – a theoretical review. Neuroimage 2000;12:1–13.
51.
Ponton CW, Don M, Eggermont JJ, Waring MD, Kwong B, Masuda A: Auditory system plasticity in children after long periods of complete deafness. Neuroreport 1996;8:61–65.
52.
Ponton CW, Don M, Waring MD, Eggermont JJ, Masuda A: Spatio-temporal source modeling of evoked potentials to acoustic and cochlear implant stimulation. Electroencephalogr Clin Neurophysiol 1993;88:478–493.
53.
Ponton CW, Eggermont JJ, Don M, Waring MD, Kwong B, Cunningham J, Trautwein P: Maturation of the mismatch negativity: Effects of profound deafness and cochlear implant use. Audiol Neurootol 2000;5:167–185.
54.
Rettenbach R, Diller G, Sireteanu R: Do deaf people see better? Texture segmentation and visual search compensate in adult but not in juvenile subjects. J Cogn Neurosci 1999;11:560–583.
55.
Roder B, Teder-Salejarvi W, Sterr A, Rosler F, Hillyard S, Neville N: Improved auditory spatial tuning in blind humans. Nature 1999;400:162–166.
56.
Rombouts SA, Scheltens P, Machielson WC, Barkhof F, Hoogenraad FG, Veltman DJ, Valk J, Witter MP: Parametric fMRI analysis of visual encoding in the human medial temporal lobe. Hippocampus 1999;9:637–643.
57.
Suarez H, Mut F, Lago G, Silveira A, De Bellis C, Velluti R, Pedemonte M, Svirsky M: Changes in the cerebral blood flow in postlingual cochlear implant users. Acta Otolaryngol 1999;119:239–243.
58.
Teissl C, Kremser C, Hochmair ES, Hochmair-Desoyer IJ: Magnetic resonance imaging and cochlear implants: Compatibility and safety aspects. J Magn Reson Imaging 1999;9:26–38.
59.
Truy E, Deiber MP, Cinotti L, Mauguiere F, Froment JC, Morgon A: Auditory cortex activity changes in long-term sensorineural deprivation during crude cochlear electrical stimulation: Evaluation by positron emission tomography. Hear Res 1995;86:34–42.
60.
Tyler RS, Fryauf-Bertschy H, Kelsay DM, Gantz BJ, Woodworth GP, Parkinson A: Speech perception by prelingually deaf children using cochlear implants. Otolaryngol Head Neck Surg 1997;117:180–187.
61.
Weber BP, Neuburger J, Goldring JE, Santogrossi T, Koestler H, Battmer RD, Lenarz T: Clinical results of the CLARION magnetless cochlear implant. Ann Otol Rhinol Laryngol Suppl 1999;177:22–26.
62.
Weeks R, Horwitz B, Aziz-Sultan A, Tian B, Wessinger CM, Cohen LG, Hallett M, Rauschecker JP: A positron emission tomographic study of auditory localization in the congenitally blind. J Neurosci 2000;20:2664–2672.
63.
Wong D, Miyamoto RT, Pisoni DB, Sehgal M, Hutchins GD: PET imaging of cochlear-implant and normal-hearing subjects listening to speech and nonspeech. Hear Res 1999;132:34–42.
64.
Young JP, O’Sullivan BT, Gibson WP, Mitchell T, Sanli H, Withall A, Cervantes R: Assessment of auditory cortical function in cochlear implant patients. Neuroimage 1998;7:S384.
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