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Flexibility and Stability in Sensory Processing Revealed Using Visual-to-Auditory Sensory Substitution.

Hertz U, Amedi A - Cereb. Cortex (2014)

Bottom Line: Secondly, associative areas changed their sensory response profile from strongest response for visual to that for auditory.Consistent features were also found in the sensory dominance in sensory areas and audiovisual convergence in associative area Middle Temporal Gyrus.These 2 factors allow for both stability and a fast, dynamic tuning of the system when required.

View Article: PubMed Central - PubMed

Affiliation: Department of Medical Neurobiology, Institute for Medical Research Israel-Canada (IMRIC), Hadassah Medical School, Hebrew University of Jerusalem, Jerusalem 91220, Israel Interdisciplinary Center for Neural Computation, The Edmond & Lily Safra Center for Brain Sciences (ELSC), Hebrew University of Jerusalem, Jerusalem 91905, Israel.

No MeSH data available.


Consistent audiovisual responses outside sensory areas. (A) A probabilistic overlap map, created from auditory and visual responses in the Pre, Post, and Plus experiments, presented on a flattened cortical reconstruction of one of the subjects. 100% overlap, marked in green, was found in the right MTG, left IPS, and left MFG, and means that these areas showed significant responses to auditory and visual stimuli in all 3 experimental conditions. (B) Auditory and visual response maps from all the experiments are presented, demonstrating consistent auditory- and visual-positive responses in the right MTG (z = 4, top row) and the left IPS (z = 35, bottom row) (compared with baseline, P < 0.05, uncorrected). These areas were responsive to auditory and visual stimuli regardless of the experimental context, task relevance, or the information they conveyed.
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BHU010F5: Consistent audiovisual responses outside sensory areas. (A) A probabilistic overlap map, created from auditory and visual responses in the Pre, Post, and Plus experiments, presented on a flattened cortical reconstruction of one of the subjects. 100% overlap, marked in green, was found in the right MTG, left IPS, and left MFG, and means that these areas showed significant responses to auditory and visual stimuli in all 3 experimental conditions. (B) Auditory and visual response maps from all the experiments are presented, demonstrating consistent auditory- and visual-positive responses in the right MTG (z = 4, top row) and the left IPS (z = 35, bottom row) (compared with baseline, P < 0.05, uncorrected). These areas were responsive to auditory and visual stimuli regardless of the experimental context, task relevance, or the information they conveyed.

Mentions: Finally, consistent audiovisual convergence was examined by using a probabilistic map overlapping all auditory and visual conditions from the 3 experiments. This analysis was carried out to detect areas that did not change their multisensory preference, that is, areas that responded similarly to auditory and visual inputs, and thus could not be detected by any of the ANOVA measures detailed above (modality, learning, or interaction effect). It could also reveal areas that did indeed demonstrate changes in sensory response profiles, but were significantly responsive to both sensory inputs. Full audiovisual convergence throughout the experiments was found in the right Middle Temporal Gyrus (MTG) and left IPS (Fig. 5). These areas showed consistent audiovisual convergence regardless of the experimental conditions in which the stimuli were delivered, with positive auditory and visual responses whenever these were present. The right MTG responded similarly to auditory and visual stimuli, regardless of their experimental context (Fig. 5B, top row), showing clear audiovisual overlap, in line with a hierarchical, bottom-up view of multisensory processing. The left IPS also showed an overlap of auditory and visual responses (Fig. 5B, bottom row). However, this area also demonstrated modulation of sensory preference on top of these consistent audiovisual convergence responses, as emerged from the ANOVA interaction effect (Fig. 4). While showing both significant auditory and visual responses throughout the experiments, the relations between these changed, in that visual responses were higher than auditory responses before learning, lower after learning, and equal during the audiovisual detection task. This consistent overlap supports a bottom-up view of multisensory perception, in that sensory inputs are processed in sensory areas and then converge in associative areas (Beauchamp et al. 2004, 2010; Calvert and Thesen 2004; van Atteveldt et al. 2004; Hertz and Amedi 2010).Figure 5.


Flexibility and Stability in Sensory Processing Revealed Using Visual-to-Auditory Sensory Substitution.

Hertz U, Amedi A - Cereb. Cortex (2014)

Consistent audiovisual responses outside sensory areas. (A) A probabilistic overlap map, created from auditory and visual responses in the Pre, Post, and Plus experiments, presented on a flattened cortical reconstruction of one of the subjects. 100% overlap, marked in green, was found in the right MTG, left IPS, and left MFG, and means that these areas showed significant responses to auditory and visual stimuli in all 3 experimental conditions. (B) Auditory and visual response maps from all the experiments are presented, demonstrating consistent auditory- and visual-positive responses in the right MTG (z = 4, top row) and the left IPS (z = 35, bottom row) (compared with baseline, P < 0.05, uncorrected). These areas were responsive to auditory and visual stimuli regardless of the experimental context, task relevance, or the information they conveyed.
© Copyright Policy - creative-commons
Related In: Results  -  Collection

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Show All Figures
getmorefigures.php?uid=PMC4494022&req=5

BHU010F5: Consistent audiovisual responses outside sensory areas. (A) A probabilistic overlap map, created from auditory and visual responses in the Pre, Post, and Plus experiments, presented on a flattened cortical reconstruction of one of the subjects. 100% overlap, marked in green, was found in the right MTG, left IPS, and left MFG, and means that these areas showed significant responses to auditory and visual stimuli in all 3 experimental conditions. (B) Auditory and visual response maps from all the experiments are presented, demonstrating consistent auditory- and visual-positive responses in the right MTG (z = 4, top row) and the left IPS (z = 35, bottom row) (compared with baseline, P < 0.05, uncorrected). These areas were responsive to auditory and visual stimuli regardless of the experimental context, task relevance, or the information they conveyed.
Mentions: Finally, consistent audiovisual convergence was examined by using a probabilistic map overlapping all auditory and visual conditions from the 3 experiments. This analysis was carried out to detect areas that did not change their multisensory preference, that is, areas that responded similarly to auditory and visual inputs, and thus could not be detected by any of the ANOVA measures detailed above (modality, learning, or interaction effect). It could also reveal areas that did indeed demonstrate changes in sensory response profiles, but were significantly responsive to both sensory inputs. Full audiovisual convergence throughout the experiments was found in the right Middle Temporal Gyrus (MTG) and left IPS (Fig. 5). These areas showed consistent audiovisual convergence regardless of the experimental conditions in which the stimuli were delivered, with positive auditory and visual responses whenever these were present. The right MTG responded similarly to auditory and visual stimuli, regardless of their experimental context (Fig. 5B, top row), showing clear audiovisual overlap, in line with a hierarchical, bottom-up view of multisensory processing. The left IPS also showed an overlap of auditory and visual responses (Fig. 5B, bottom row). However, this area also demonstrated modulation of sensory preference on top of these consistent audiovisual convergence responses, as emerged from the ANOVA interaction effect (Fig. 4). While showing both significant auditory and visual responses throughout the experiments, the relations between these changed, in that visual responses were higher than auditory responses before learning, lower after learning, and equal during the audiovisual detection task. This consistent overlap supports a bottom-up view of multisensory perception, in that sensory inputs are processed in sensory areas and then converge in associative areas (Beauchamp et al. 2004, 2010; Calvert and Thesen 2004; van Atteveldt et al. 2004; Hertz and Amedi 2010).Figure 5.

Bottom Line: Secondly, associative areas changed their sensory response profile from strongest response for visual to that for auditory.Consistent features were also found in the sensory dominance in sensory areas and audiovisual convergence in associative area Middle Temporal Gyrus.These 2 factors allow for both stability and a fast, dynamic tuning of the system when required.

View Article: PubMed Central - PubMed

Affiliation: Department of Medical Neurobiology, Institute for Medical Research Israel-Canada (IMRIC), Hadassah Medical School, Hebrew University of Jerusalem, Jerusalem 91220, Israel Interdisciplinary Center for Neural Computation, The Edmond & Lily Safra Center for Brain Sciences (ELSC), Hebrew University of Jerusalem, Jerusalem 91905, Israel.

No MeSH data available.