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The Journal of Neuroscience, November 15, 2002, 22(22):9941-9944
Expansion of the Tonotopic Area in the Auditory Cortex of the
Blind
Thomas
Elbert1,
Annette
Sterr2,
Brigitte
Rockstroh1,
Christo
Pantev3,
Matthias M.
Müller2, and
Edward
Taub4, 5
1 Department of Psychology, University of Konstanz,
D-78457 Konstanz, Germany, 2 Department of Psychology,
University of Liverpool, Liverpool L69 7ZA, United Kingdom,
3 Rotman Research Institute for Neuroscience, Toronto,
Ontario, Canada M6A 2E1, 4 Department of Psychology,
University of Alabama at Birmingham, Alabama 35294, and
5 Birmingham Veterans Affairs Medical Center, Birmingham,
Alabama 35233
 |
ABSTRACT |
A part of the core area of the auditory cortex was examined in nine
blind and10 sighted individuals by magnetic source imaging and was
found to be enlarged by a factor of 1.8 in the blind compared with the
sighted humans. Moreover, the latency of the N1m component of the
auditory-evoked magnetic response was significantly decreased in the
blind. The development of use-dependent cortical reorganization may be
a consequence of the absence of visual input in combination with
enhanced auditory activity generated by the long-term concentration by
blind individuals on nonvisual cues to interact appropriately with the
environment. It is consistent with and well suited to mediate the
demonstrated increased ability of the blind to accurately localize
acoustic sources in peripheral auditory fields and to decode speech.
Key words:
tonotopic map; auditory cortex; reorganization; blind; MEG
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INTRODUCTION |
Blind individuals are forced by the
nature of their disability to depend on nonvisual modalities, including
audition, for information about their external environment. When
attention is directed to peripheral auditory space, localization of
sounds has been shown to be better in blind than in sighted people
(Muchnik et al., 1991 ; Lessard et al., 1998 ; Röder et al.,
1999a ). Data on sound localization in the frontal region (Zwiers
et al., 2001 ) and other auditory discriminative abilities is less
conclusive (Stankov and Spilsbury, 1978 ). Whether or not the full range
of auditory perceptual ability is improved in the blind, it is
nevertheless the case that sensory input over nonvisual avenues becomes
of greater behavioral relevance to these individuals to enable
effective interaction with the world around them.
Focused attention on behaviorally relevant stimulation over extended
periods has been found to produce a substantial enlargement in the
representational zones of the involved portions of the body in
somatosensory cortex in research with animals (Merzenich et al., 1984 ;
Jenkins et al., 1990 ) and humans (Elbert et al., 1994 , 1995 , 1998 ;
Sterr et al., 1998a ,b ). Similarly, the primary auditory cortical fields
can be dramatically refined or profoundly degraded. Use-dependent
reorganization in the frequency receptive fields has been demonstrated
by a number of groups (Bakin and Weinberger, 1990 ; Recanzone et
al., 1993 ; Ohl and Scheich, 1996 ).
Increasing interest has been devoted to the phenomenon of cross-modal
plasticity in blind humans, such that auditory (Kujala et al., 1992 ,
1995a ,b , 1997 ; Alho et al., 1993 ; Rösler et al., 1993 ;
Weeks et al., 2000 ) and tactile (Rösler et al., 1993 ; Uhl et al.,
1993 ; Kujala et al., 1995b ; Röder et al., 1996 , 1997 ; Cohen et al., 1997 ) stimuli come to be processed in visual cortex. Rauschecker et al. (1992) , for instance, found in cats and mice deprived of vision from birth, a supernormal growth of facial vibrissae
and an enlarged whisker representation in the somatosensory cortical
barrel field. There has been little work evaluating the prediction from
the use-dependent cortical reorganization literature that there would
be a related but more direct effect, i.e., increased reliance on the
auditory modality would give rise to alterations in the auditory areas
of the brain. In one relevant experiment, Hamilton et al. (2000) found
an increased prevalence of absolute pitch in blind musicians.
The present study explored changes in the auditory cortex
of blind individuals as a consequence of the enhanced, visual
deprivation-enforced auditory processing. An expansion of regions
within the auditory cortex was expected as an indication of
use-dependent cortical reorganization. Considering the evidence
of the global functional organization of the auditory cortex and its
topographic representation of stimulus and processing domains
(Rauschecker, 1998 ; Schreiner, 1998 ; Rauschecker and Tian, 2000 ), the
tonotopic map can be reconstructed from the auditory magnetic response
to pure tones. Recently, Godey et al. (2001) validated the presently
used neuromagnetic source localization of auditory-evoked fields with
source localization from intracerebral-evoked potentials and
demonstrated that both methods suggest that the auditory-evoked N1 may
be generated from sources in the intermediate and lateral parts of the
Heschl's gyrus and in the planum temporale. The present study, using
magnetic source localization, explored whether the increased dependence on the auditory modality in blind individuals would result in an
alteration of regions in the auditory cortex.
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MATERIALS AND METHODS |
Nine blind (four male, five female; mean age, 39.4 ± 6.1;
range, 27-46 years) and 10 sighted (five male, five female; mean age,
37.1 ± 6.8; range, 29-47 years) subjects participated in the
study. Five of the blind subjects were blind from birth; four had
become blind as adults between the ages of 16 and 30 years, with their
mean duration of blindness being 8.3 ± 3.8 years. In all cases,
blindness was attributable to peripheral damage of the visual
system, and there were no additional neurological problems. All
subjects were right handed, and audiological examinations indicated a
normal status. Informed consent was obtained from each subject after
they received a detailed explanation concerning the nature of the study.
Magnetic fields evoked by sequences of acoustic stimuli were recorded
simultaneously from the right and left hemispheres using a 148-channel
whole-head neuromagnetometer. For recording, subjects were placed in a
supine position that was made as comfortable as possible to prevent
head and body movement. The recording device (Magnes 2500; 4-D
Neuroimaging, San Diego, CA) was operated within a magnetically
shielded room. The magnetic sensing devices (magnetometers) were
separated by 28 mm and were arranged in a uniformly distributed array
on the inside surface of a helmet.
Four series of 128 tone bursts each were delivered monaurally to the
right ear, at 60 dB above individually determined hearing level.
For each series, stimuli had a carrier frequency of 0.5, 1, 2, or 4 kHz; the sequence of frequencies was randomized across subjects
according to a fixed irregular order. Each tone burst was 500 msec in
duration, with 10 msec rise and fall time with a cosine slope. Stimuli
were presented through a nonmagnetic and echo-free stimulus delivery
system (6.3 m in length, 16 mm inner diameter) with an almost linear
frequency characteristic (deviations less than ±4 dB in the range
between 200 and 4000 Hz). The interstimulus interval varied randomly
between 2.7 and 3.3 sec.
Stimulus-related epochs were recorded with a bandwidth of 1-100 Hz and
sampled at 387.5 Hz. Epochs contaminated by muscle or eye blink
artifacts with amplitude variations of >3 pT in any channel were
automatically rejected from additional analysis. The averaged evoked
fields were filtered from 1 to 20 Hz and referred to a 100 msec
prestimulus baseline. Source analysis followed the procedure developed
by Pantev et al. (1989 , 1995 , 1998 ). Subsets of ~40 channels centered
around the source location and including the signal extrema were
selected for analysis for the left or the right auditory areas, separately.
When the equivalent current dipole for a given frequency did not
match one of the criteria, it was excluded from estimation of the
regression line. On the contralateral side, this was the case for one
sighted and two blind subjects, and, on the ipsilateral side, it was
true for one sighted and three blind subjects. In four subjects (three
sighted and one blind), two or more source locations did not match the
criteria for a focal source, and, therefore, no regression parameters
were computed. Mean residual variance was 1.6 times greater in the
blind than in sighted subjects.
 |
RESULTS |
Consistent with previous findings for sighted individuals (Pantev
et al., 1988 ,1989 , 1995 , 1998 ; Mäkelä, 1988 ), the N1m peak
occurred at an earlier latency over the contralateral hemisphere than
over the ipsilateral hemisphere in both groups (mean contralateral latency across all subjects, 109.3 ± 17.4 msec; mean ipsilateral latency, 119.7 ± 14.3 msec;
F(1,15) = 16.5; p < 0.01). In the blind subjects, N1m latencies were consistently shorter
than in the sighted subjects (107.0 ± 12.4 msec for the blind and
121.40 ± 17.14 msec for the sighted subjects, both hemispheres;
F(1,15) = 4.6; p < 0.05). This group difference was significant for both the contralateral
(16.4 msec) and the ipsilateral (11.8 msec) hemispheres. Frequency did
not have a significant effect on N1 latencies (main effect,
p = 11; interactions, all F values <1; all
mean differences were smaller than 5 msec).
A dipolar structure for the N1m component was observed over each
hemisphere and was similar in blind and sighted individuals. The global
field power [root mean square (rms) across subsets of
channels] and the N1m dipole moment (Q), representing the N1m source
strength, showed a larger contralateral (rms, 155.8 ± 76.2 fT; Q,
37.9 ± 29.1 nAm) than ipsilateral magnitude (rms,
128.5 ± 54.6 fT; Q, 25.7 ± 17.6 nAm;
Frms(1,15) = 14.1; p < 0.01; FQ(1,15) = 14.1;
p < 0.01). On average, these measures of N1m amplitude were somewhat larger for the sighted than for the blind subjects, but
the difference between blind and sighted subjects with respect to these
measures of N1m magnitude did not reach significance. For the analysis
of the rms, as a measure of signal power, which does not require source
modeling, all subjects could be included in the analysis; there was not
a significant main effect of groups (F(1,17) = 1.5; p = 0.24). A drop of signal power with stimulation frequency (Fig.
1a) was present equally in
both groups (main effect for frequency,
F(3,51) = 14.2; p < 0.01). Figure 1 plots the rms and the N1m source locations against the
logarithms of the four standard frequencies used in this experiment for
blind and sighted individuals.

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Figure 1.
The change in signal power
(a) and source location on the mediolateral axis
(b) is shown as a function of stimulus frequency,
averaged separately for the two groups. The bar graphs on the
right illustrate that the effects [smaller signal power
(NS) and expanded map size (p < 0.01) in the blind] can be observed equally in both hemispheres. The
observation that the area across which the four different
frequencies respond is larger in the blind whereas the signal power
tends to be smaller suggests that the neuronal pool activated by a
given sinusoidal tone is more specific in the blind than in sighted
individuals. Error bars indicate SEs.
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|
The core areas of auditory cortex and adjacent regions exhibit a
tonotopic arrangement in humans such that higher frequencies are
represented medially and lower frequencies are represented progressively more laterally (Pantev et al., 1988 , 1989 ). When N1m
dipole locations are plotted against the logarithm of frequency (Fig.
1b), they can be represented (with interpolation) by a
straight line (Pantev et al., 1995 , 1998 ). The steeper the slope of
this regression line, the more extended is the map of the tonotopic representation. The absolute slope of this regression line for the
sighted individuals is 1.84 times steeper than for the blind individuals, indicating that the tonotopic map for blind individuals is
84% larger in the blind than in sighted (p = 0.001) (Fig. 1b). As illustrated in the right
panel of Figure 1b, this effect was present to the same
extent in both hemispheres. When the two regression coefficients were
averaged across hemispheres (ignoring missing values from one
hemisphere), absolute coefficients were obtained for all 19 subjects;
the main effect of group was F(1,17) = 13.2 (p < 0.01). The effect remained
significant, when only those five blind and five sighted subjects were
included for whom there was a complete set of source models, i.e., a
current dipole could be fitted for each frequency in each hemisphere
(F(1,8) = 9.2; p < 0.02). The averages of these subgroups were almost identical with the
averages across all subjects.
 |
DISCUSSION |
The early research on use-dependent cortical reorganization
(Merzenich et al., 1984 ; Jenkins et al., 1990 ) indicated that it was
the behavioral relevance of afferent input that was responsible for
increases in the size of cortical representational zones associated with the reception of that input rather than simply the amount of
incoming stimulation. Blind individuals do not receive more auditory
stimulation than sighted individuals. However, to interact effectively
with their environment, they have to rely on nonvisual, primarily
auditory input to a greater extent.
Behavioral relevance as a source of use-dependent reorganization
suggests the possibility that the expansion might have some value in
the functional economy of the individual. It has been shown that the
localization of sounds in peripheral fields (Lessard et al., 1998 ;
Röder et al., 1999a ) and other central auditory skills
(Muchnik et al., 1991 ) are better in blind than sighted individuals.
This capability should be of value in the blind, who are unable to use
vision to discriminate the location of objects and potential avenues
for progression. Sound localization is generally considered to be a
function of binaural cues processed in the auditory cortex. However, it
has been argued (Rauschecker, 1999 ) that there can be a second set of
cues based on specific filtering of sounds by the head and pinnae that
provide information concerning the spatial origin of acoustic stimuli.
It is possible that the expansion of the tonotopic map in the blind
might in some way be involved in providing a basis for the very subtle
discriminations that would be required to improve this type of
capability. For example, a larger neural network would have a higher
fidelity and, consequently, as previously demonstrated, a greater speed at which temporal auditory discriminations could be made. In fact, monaural sound localization is enhanced in the blind (Lessard et al.,
1998 ). Moreover, a more efficient encoding of verbal material (Röder et al., 2001 ) has been reported. This capability may also be mediated by the enlarged cortical representation given that the
frequency spectrum used in the present study covers the sound spectrum
of language. Finally, our findings might also explain the shorter
refractory periods observed in the blind for the N1 evoked potential
component (Röder et al., 1999b ).
Previously, we showed in blind individuals that there is an increase
and alteration in the functional organization of the area of the cortex
receiving somatosensory information (Sterr et al., 1998a ,b ), and
Pascual-Leone and Torres (1993) have shown that a similar phenomenon
takes place in motor cortex. Recently, attention has also been focused
on the intriguing phenomenon of cross-modal plasticity in blind
individuals whereby auditory and somatosensory input comes to be
processed in the visual areas in the brain (Rauschecker, 1995 ; Kujala
et al., 2000 ). These areas have been deprived of their normal source of
visual sensory input and might therefore otherwise be unused. We found
no activity in the latency range below 120 msec that could be fitted by
dipolar sources in visual areas and thus no evidence of short-latency processing of simple auditory input in visual cortex in blind people.
However, the auditory map, which we determined had expanded greatly in
blind individuals, is situated in the area of the brain that does carry
out short-latency processing of auditory input by the nature of its
built-in structural connectivity. This is fundamental to later auditory
processing, which can involve regions adjacent to primary auditory
cortex, as in sighted individuals, and also distant locations, as in
the blind.
One plausible explanation of the expansion of auditory cortex in blind
individuals found in the present study is the elaboration of a
use-dependent cortical reorganization involving either an unmasking of
previously silent connections and/or sprouting of new neural elements
from those that previously existed. Alternate hypotheses are possible.
For example, blindness could lead to reduced cell death in the cortical
territory of other modalities, including auditory cortex, or to
stabilization of transient connections. It also seems possible that an
expanded auditory area might include a larger number of contributing
neurons and hence larger dipole moments. Another possibility is that
the frequency tuning of neurons might become more frequency specific
with the consequence that a tone of a particular frequency would
activate a smaller set of neurons; an expansion of the auditory cortex
would thus be needed to house more such sets (Bakin and Weinberger,
1990 ). The mechanisms are not mutually exclusive, and, in some cases,
they are partially overlapping; the present data do not permit
determination of which were operative. It also remains questionable
whether the expanded tonotopic map observed here has a causal
relationship to the auditory discrimination abilities observed to be
enhanced in the blind noted above.
However, the expansion of the tonotopic map observed in this experiment
does supplement the picture of the way in which the brain reorganizes
itself in response to blindness, possibly as a result of the blind
individuals' greater attention to and reliance on nonvisual sensory
avenues to maintain adequate commerce with the world around them. The
expansion of the tonotopic map, the reorganization of somatosensory
cortex, and cross-modal plasticity in the blind (Rösler et al.,
1993 ; Kujala et al., 1995a , 1997 ; Sadato et al., 1996 ;
Cohen et al., 1997 ; Sterr et al., 1998a ,b ) would appear to be an
excellent composite example of the principle formulated by Merzenich et
al. (1984) of the continual competition for cortical space. When there
is increased use of a body part of type of sensory discrimination, the
representational zones within the brain normally responsible for
mediating those functions expand at the expense of other regions that
are currently not being used to the same extent.
 |
FOOTNOTES |
Received June 28, 2002; revised Aug. 28, 2002; accepted Sept. 3, 2002.
This study was supported by the Deutsche Forschungsgemeinschaft, the
Volkswagenstiftung, and Grants B95-975R and W98 0410 from the
Rehabilitation Research and Development Service, United States
Department of Veterans Affairs. We thank A. Keil, B. Röder, and
F. Rösler for comments on this manuscript.
Correspondence should be addressed to Dr. Thomas Elbert, University of
Konstanz, P.O. Box D25, D-78457 Konstanz, Germany. E-mail:
thomas.elbert{at}uni-konstanz.de.
 |
REFERENCES |
-
Alho K,
Kujala T,
Paavilainen P,
Summala H,
Näätänen R
(1993)
Auditory processing in visual brain areas of the early blind: evidence from event-related potentials.
Electroencephalogr Clin Neurophysiol
86:418-427[Medline].
-
Bakin JS,
Weinberger NM
(1990)
Calssical conditioning induces CS-specific receptive field plasticity in the auditory cortex of the guinea pig.
Brain Res
536:271-286[ISI][Medline].
-
Cohen LG,
Celnick P,
Pascual-Leone A,
Corwell B,
Faiz L,
Dambrosia J,
Honda M,
Sadato N,
Gerloff C,
Catala MD,
Hallett M
(1997)
Functional relevance of cross-model plasticity in blind humans.
Nature
389:180-183[Medline].
-
Elbert T,
Flor H,
Birbaumer N,
Knecht S,
Hampson S,
Taub E
(1994)
Extensive reorganization of the somatosensory cortex in adult humans after nervous system injury.
NeuroReport
5:2593-2597[ISI][Medline].
-
Elbert T,
Pantev C,
Wienbruch C,
Rockstroh B,
Taub E
(1995)
Increased use of the left hand in string players associated with increased cortical representation of the fingers.
Science
270:305-307[Abstract/Free Full Text].
-
Elbert T,
Candia V,
Altenmüller E,
Rau H,
Sterr A,
Rockstroh B,
Pantev C,
Taub E
(1998)
Alteration of digital representations in somatosensory cortex in focal hand dystonia.
NeuroReport
16:3571-3575.
-
Godey B,
Schwartz D,
de Graaf JB,
Chauvel P,
Liégeois-Chauvel C
(2001)
Neuromagnetic source localization of auditory evoked fields and intracerebral evoked potentials: a comparison of data in the same patients.
Clin Neurophysiol
112:1850-1859[ISI][Medline].
-
Hamilton RH,
Pascual-Leone A,
Rodriguez D,
Schlaug G
(2000)
Increased prevalence of absolute pitch in blind musicians.
Soc Neurosci Abstr
26:739.13.
-
Jenkins WM,
Merzenich MM,
Ochs MT,
Allard T,
Guic-Robles E
(1990)
Functional reorganisation of primary somatosensory cortex in adult owl monkeys after behaviorally controlled tactile stimulation.
J Neurophysiol
63:82-104[Abstract/Free Full Text].
-
Kujala T,
Alho K,
Paavilainen P,
Summala H,
Näätänen R
(1992)
Neuronal plasticity in processing of sound location by the early blind: an event-related potential study.
Electroencephalogr Clin Neurophysiol
84:469-472[Medline].
-
Kujala T,
Huotilainen M,
Snikkonen J,
Ahonen AI,
Alho K,
Hämäläinen MS,
Ilmoniemi RJ,
Kajola M,
Knuutila JET,
Lavikainen J,
Salonen O,
Simola J,
Standertskjöld-Nordenstam CG,
Näätänen R
(1995a)
Visual cortex activation in blind humans during sound discrimination.
Neurosci Lett
183:143-146[ISI][Medline].
-
Kujala T,
Alho K,
Kekoni J,
Hämäläinen MS,
Reinikainen K,
Salonen O,
Standertskjöld-Nordenstam CG,
Näätänen R
(1995b)
Auditory and somatosensory event-related brain potentials in early blind humans.
Exp Brain Res
104:519-526[ISI][Medline].
-
Kujala T,
Alho K,
Huotilainen M,
Ilmoniemi RJ,
Lehtokoki A,
Leinonen A,
Rinne T,
Salonen O,
Snikkonen J,
Standertskjöld-Nordenstam C-G,
Näätänen R
(1997)
Electrophysiological evidence for cross-modal plasticity in humans with early- and late-onset blindness.
Psychophysiology
34:213-216[ISI][Medline].
-
Kujala T,
Alho K,
Näätänen R
(2000)
Cross-modal reorganization of human cortical functions.
Trends Neurosci
23:115-120[ISI][Medline].
-
Lessard N,
Paré M,
Lepore F,
Lassonde M
(1998)
Early-blind human subjects localize sound sources better than sighted subjects.
Nature
395:278-280[Medline].
-
Mäkelä JP
(1988)
Contra- and ipsilateral auditory stimuli produce different activation patterns at the human auditory cortex: a neuromagnetic study.
Pflügers Arch
412:12-16[Medline].
-
Merzenich MM,
Nelson RJ,
Stryker MP,
Cynader MS,
Schoppmann A,
Zook JM
(1984)
Somatosensory cortical map changes following digit amputation in adult monkeys.
J Comp Neurol
224:591-605[ISI][Medline].
-
Muchnik C,
Efrati M,
Nemeth E,
Malin M,
Hildesheimer M
(1991)
Central auditory skills in blind and sighted subjects.
Scand Audiol
20:19-23[ISI][Medline].
-
Ohl F,
Scheich H
(1996)
Differential frequency conditioning enhances spectral contrast sensitivity of units in auditory cortex (field Al) of the alert Mongolian gerbil.
Eur J Neurosci
96:100-117.
-
Pantev C,
Hoke M,
Lehnertz K,
Lütkenhöner B,
Anogianakis G,
Wittkowski W
(1988)
Tonotopic organization of the human auditory cortex revealed by transient auditory evoked magnetic fields.
Electroencephalogr Clin Neurophysiol
69:160-170[ISI][Medline].
-
Pantev C,
Hoke M,
Lütkenhöner B,
Lehnertz K
(1989)
Tonotopic organization of the auditory cortex: pitch versus frequency representation.
Science
246:486-488[Abstract/Free Full Text].
-
Pantev C,
Bertrand O,
Eulitz C,
Verkindt C,
Hampson S,
Schuirer G,
Elbert T
(1995)
Specific tonotopic organizations of different areas of human auditory cortex revealed by simultaneous magnetic and electric recordings.
Electroencephalogr Clin Neurophysiol
94:26-40[ISI][Medline].
-
Pantev C,
Ross B,
Berg P,
Elbert T,
Rockstroh B
(1998)
Study of the human auditory cortices using a whole-head magnetometer: left vs. right hemisphere and ipsilateral vs. contralateral stimulation.
Audiol Neurootol
3:183-190[Medline].
-
Pascual-Leone A,
Torres F
(1993)
Plasticity of the sensorimotor cortex representation of the reading finger in Braille readers.
Brain
116:39-52[Abstract/Free Full Text].
-
Rauschecker JP
(1995)
Compensatory plasticity and sensory substitution in the cerebral cortex.
Trends Neurosci
18:36-43[ISI][Medline].
-
Rauschecker JP
(1998)
Cortical processing of complex sounds.
Curr Opin Neurobiol
8:516-521[ISI][Medline].
-
Rauschecker JP
(1999)
Auditory cortical plasticity: a comparison with other sensory systems.
Trends Neurosci
22:74-80[ISI][Medline].
-
Rauschecker JP,
Tian B
(2000)
Mechanisms and streams for processing of "what" and "where" in auditory cortex.
Proc Natl Acad Sci USA
97:11800-11806[Abstract/Free Full Text].
-
Rauschecker JP,
Tian B,
Korte M,
Egert U
(1992)
Crossmodal changes in the somatosensory vibrissa/barrel system of visually deprived animals.
Proc Natl Acad Sci USA
89:5063-5067[Abstract/Free Full Text].
-
Recanzone GH,
Schreiner CE,
Merzenich MM
(1993)
Plasticity in the frequency representation of primary auditory cortex following discrimination training in adult owl monkeys.
J Neuroscience
13:87-103[Abstract].
-
Röder B,
Rösler F,
Henninghausen E,
Näcker F
(1996)
Event-related potentials during auditory and somatosensory discrimination in sighted and blind human subjects.
Cogn Brain Res
4:77-93[Medline].
-
Röder B,
Rösler F,
Henninghausen E
(1997)
Different cortical activation patterns in blind and sighted humans during encoding and transformation of haptic images.
Psychophysiology
34:292-307[ISI][Medline].
-
Röder B,
Teder-Sälejärvi W,
Sterr A,
Rösler F,
Hillyard SA,
Neville HJ
(1999a)
Improved auditory spatial tuning in blind humans.
Nature
400:162-166[Medline].
-
Röder B,
Rösler F,
Neville HJ
(1999b)
Effects of interstimulus interval on auditory event-related potentials in congenitally blind and normally sighted humans.
Neurosci Lett
264:53-56[Medline].
-
Röder B,
Rösler F,
Neville HJ
(2001)
Auditory memory in congenitally blind adults: a behavioral-electrophysiological investigation.
Cogn Brain Res
11:289-303[Medline].
-
Rösler F,
Röder B,
Heil M,
Hennighausen E
(1993)
Topographic differences of slow event-related brain potentials in blind and sighted adult human subjects during haptic mental rotation.
Cogn Brain Res
1:145-159[Medline].
-
Sadato N,
Pascual-Leone A,
Grafman J,
Ibanes V,
Deiber MP,
Dold G,
Hallett M
(1996)
Activation of the primary visual cortex by Braille reading in blind subjects.
Nature
380:527-528.
-
Schreiner CE
(1998)
Spatial distribution of responses to simple and complex sounds in the primary auditory cortex.
Audiol Neurootol
3:104-122[Medline].
-
Stankov L,
Spilsbury G
(1978)
The measurement of auditory abilities of blind, partially sighted, and sighted children.
Appl Psychol Meas
2:491-503.
-
Sterr A,
Müller MM,
Elbert T,
Rockstroh B,
Taub E
(1998a)
Changed perceptions in Braille readers.
Nature
391:134-135[Medline].
-
Sterr A,
Müller MM,
Elbert T,
Rockstroh B,
Pantev C,
Taub E
(1998b)
Perceptual correlates of changes in cortical representation of fingers in blind multifinger Braille readers.
J Neurosci
18:4417-4423[Abstract/Free Full Text].
-
Uhl F,
Franzen P,
Podreka I,
Steiner M,
Deecke L
(1993)
Increased regional cerebral blood flow in inferior occipital cortex and cerebellum of early blind humans.
Neurosci Lett
150:162-164[ISI][Medline].
-
Weeks R,
Horwitz B,
Aziz-Sultan A,
Tian B,
Wessinger CM,
Cohen LG,
Hallett M,
Rauschecker JP
(2000)
A positron emission tomographic study of auditory localization in the congenitally blind.
J Neurosci
20:2664-2672[Abstract/Free Full Text].
-
Zwiers MP,
Van Opstal AJ,
Cruysberg JRM
(2001)
A spatial hearing deficit in early-blind humans.
J Neurosci
21:RC142[Abstract/Free Full Text](1-5).
Copyright © 2002 Society for Neuroscience 0270-6474/02/22229941-04$05.00/0
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