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Cortical circuits for silent speechreading in deaf and hearing people.

Capek CM, Macsweeney M, Woll B, Waters D, McGuire PK, David AS, Brammer MJ, Campbell R - Neuropsychologia (2007)

Bottom Line: In contrast to earlier findings, activation in left middle and posterior portions of superior temporal cortex, including regions within the lateral sulcus and the superior and middle temporal gyri, was greater for deaf than hearing participants.Deaf participants showed a positive correlation between speechreading skill and activation in the middle/posterior superior temporal cortex.Together, these findings indicate that activation in the left superior temporal regions for silent speechreading can be modulated by both hearing status and speechreading skill.

View Article: PubMed Central - PubMed

Affiliation: Deafness, Cognition and Language Research Centre, Division of Psychology and Language Sciences, University College London, 49 Gordon Square, London WC1H 0PD, United Kingdom. c.capek@ucl.ac.uk

ABSTRACT
This fMRI study explored the functional neural organisation of seen speech in congenitally deaf native signers and hearing non-signers. Both groups showed extensive activation in perisylvian regions for speechreading words compared to viewing the model at rest. In contrast to earlier findings, activation in left middle and posterior portions of superior temporal cortex, including regions within the lateral sulcus and the superior and middle temporal gyri, was greater for deaf than hearing participants. This activation pattern survived covarying for speechreading skill, which was better in deaf than hearing participants. Furthermore, correlational analysis showed that regions of activation related to speechreading skill varied with the hearing status of the observers. Deaf participants showed a positive correlation between speechreading skill and activation in the middle/posterior superior temporal cortex. In hearing participants, however, more posterior and inferior temporal activation (including fusiform and lingual gyri) was positively correlated with speechreading skill. Together, these findings indicate that activation in the left superior temporal regions for silent speechreading can be modulated by both hearing status and speechreading skill.

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Activation for the speechreading condition as a function of hearing status. The region indicated was more active for deaf than hearing participants, when performance on the TAS (z-score) was entered as a covariate (voxel-wise p-value = 0.05, cluster-wise p-value = 0.01). No regions were more active for hearing than deaf participants. No right hemisphere regions were significantly different across the groups. Five sequential axial sections, showing activation in superior temporal regions, including the planum temporale (PT) and Heschl's gyrus (HG) are also displayed.
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fig2: Activation for the speechreading condition as a function of hearing status. The region indicated was more active for deaf than hearing participants, when performance on the TAS (z-score) was entered as a covariate (voxel-wise p-value = 0.05, cluster-wise p-value = 0.01). No regions were more active for hearing than deaf participants. No right hemisphere regions were significantly different across the groups. Five sequential axial sections, showing activation in superior temporal regions, including the planum temporale (PT) and Heschl's gyrus (HG) are also displayed.

Mentions: When speechreading performance, as indicated by individual TAS z-score, was entered as a covariate into this analysis, deaf participants displayed greater activation than hearing participants in the left temporal cortex. The cluster of activation (120 voxels) was focused at the border between the posterior superior temporal gyrus (i.e., planum temporale) and the transverse temporal (i.e., Heschl's) gyrus (BA 42/41; x = −54, y = −22, z = 10). The focus of this cluster was verified using probabilistic maps provided by Penhune, Zatorre, MacDonald, and Evans (1996) (25–50% probability of Heschl's gyrus) and Westbury, Zatorre, and Evans (1999) (26–45% probability of planum temporale). Based on these probability maps, 15 voxels within this cluster, displayed ≥50% probability of being located in Heschl's gyrus, and five voxels showed ≥46% probability of being in planum temporale. This cluster also extended into the posterior lateral portion of the superior temporal gyrus (BA 22) and the middle and posterior portions of the superior temporal sulcus and middle temporal gyrus (BA 21; see Fig. 2). No brain regions were significantly more active in hearing than deaf participants when speechreading was a covariate in the analysis.


Cortical circuits for silent speechreading in deaf and hearing people.

Capek CM, Macsweeney M, Woll B, Waters D, McGuire PK, David AS, Brammer MJ, Campbell R - Neuropsychologia (2007)

Activation for the speechreading condition as a function of hearing status. The region indicated was more active for deaf than hearing participants, when performance on the TAS (z-score) was entered as a covariate (voxel-wise p-value = 0.05, cluster-wise p-value = 0.01). No regions were more active for hearing than deaf participants. No right hemisphere regions were significantly different across the groups. Five sequential axial sections, showing activation in superior temporal regions, including the planum temporale (PT) and Heschl's gyrus (HG) are also displayed.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC2394569&req=5

fig2: Activation for the speechreading condition as a function of hearing status. The region indicated was more active for deaf than hearing participants, when performance on the TAS (z-score) was entered as a covariate (voxel-wise p-value = 0.05, cluster-wise p-value = 0.01). No regions were more active for hearing than deaf participants. No right hemisphere regions were significantly different across the groups. Five sequential axial sections, showing activation in superior temporal regions, including the planum temporale (PT) and Heschl's gyrus (HG) are also displayed.
Mentions: When speechreading performance, as indicated by individual TAS z-score, was entered as a covariate into this analysis, deaf participants displayed greater activation than hearing participants in the left temporal cortex. The cluster of activation (120 voxels) was focused at the border between the posterior superior temporal gyrus (i.e., planum temporale) and the transverse temporal (i.e., Heschl's) gyrus (BA 42/41; x = −54, y = −22, z = 10). The focus of this cluster was verified using probabilistic maps provided by Penhune, Zatorre, MacDonald, and Evans (1996) (25–50% probability of Heschl's gyrus) and Westbury, Zatorre, and Evans (1999) (26–45% probability of planum temporale). Based on these probability maps, 15 voxels within this cluster, displayed ≥50% probability of being located in Heschl's gyrus, and five voxels showed ≥46% probability of being in planum temporale. This cluster also extended into the posterior lateral portion of the superior temporal gyrus (BA 22) and the middle and posterior portions of the superior temporal sulcus and middle temporal gyrus (BA 21; see Fig. 2). No brain regions were significantly more active in hearing than deaf participants when speechreading was a covariate in the analysis.

Bottom Line: In contrast to earlier findings, activation in left middle and posterior portions of superior temporal cortex, including regions within the lateral sulcus and the superior and middle temporal gyri, was greater for deaf than hearing participants.Deaf participants showed a positive correlation between speechreading skill and activation in the middle/posterior superior temporal cortex.Together, these findings indicate that activation in the left superior temporal regions for silent speechreading can be modulated by both hearing status and speechreading skill.

View Article: PubMed Central - PubMed

Affiliation: Deafness, Cognition and Language Research Centre, Division of Psychology and Language Sciences, University College London, 49 Gordon Square, London WC1H 0PD, United Kingdom. c.capek@ucl.ac.uk

ABSTRACT
This fMRI study explored the functional neural organisation of seen speech in congenitally deaf native signers and hearing non-signers. Both groups showed extensive activation in perisylvian regions for speechreading words compared to viewing the model at rest. In contrast to earlier findings, activation in left middle and posterior portions of superior temporal cortex, including regions within the lateral sulcus and the superior and middle temporal gyri, was greater for deaf than hearing participants. This activation pattern survived covarying for speechreading skill, which was better in deaf than hearing participants. Furthermore, correlational analysis showed that regions of activation related to speechreading skill varied with the hearing status of the observers. Deaf participants showed a positive correlation between speechreading skill and activation in the middle/posterior superior temporal cortex. In hearing participants, however, more posterior and inferior temporal activation (including fusiform and lingual gyri) was positively correlated with speechreading skill. Together, these findings indicate that activation in the left superior temporal regions for silent speechreading can be modulated by both hearing status and speechreading skill.

Show MeSH