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Visual and audiovisual effects of isochronous timing on visual perception and brain activity.

Marchant JL, Driver J - Cereb. Cortex (2012)

Bottom Line: Visual isochrony activated a similar timing-related brain network to that previously found primarily in auditory beat perception work.Finally, activity in multisensory left posterior superior temporal sulcus increased specifically during concurrent isochronous audiovisual presentations.These results indicate that regular isochronous timing can modulate visual processing and this can also involve multisensory audiovisual brain mechanisms.

View Article: PubMed Central - PubMed

Affiliation: Wellcome Trust Centre for Neuroimaging, UCL Institute of Neurology, London WC1N 3BG, UK. jennifer.marchant@ucl.ac.uk

ABSTRACT
Understanding how the brain extracts and combines temporal structure (rhythm) information from events presented to different senses remains unresolved. Many neuroimaging beat perception studies have focused on the auditory domain and show the presence of a highly regular beat (isochrony) in "auditory" stimulus streams enhances neural responses in a distributed brain network and affects perceptual performance. Here, we acquired functional magnetic resonance imaging (fMRI) measurements of brain activity while healthy human participants performed a visual task on isochronous versus randomly timed "visual" streams, with or without concurrent task-irrelevant sounds. We found that visual detection of higher intensity oddball targets was better for isochronous than randomly timed streams, extending previous auditory findings to vision. The impact of isochrony on visual target sensitivity correlated positively with fMRI signal changes not only in visual cortex but also in auditory sensory cortex during audiovisual presentations. Visual isochrony activated a similar timing-related brain network to that previously found primarily in auditory beat perception work. Finally, activity in multisensory left posterior superior temporal sulcus increased specifically during concurrent isochronous audiovisual presentations. These results indicate that regular isochronous timing can modulate visual processing and this can also involve multisensory audiovisual brain mechanisms.

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Positive linear relation between changes in performance and beta parameter estimates in sensory cortices for isochrony. Task-related peak voxels were identified in bilateral auditory (superior temporal gyrus, STG) and visual (occipital lobe) cortices per participant. Isochrony-induced voxel beta parameter change in (a) left and (b) right STG, or (c) left and (d) right occipital lobe are plotted against change in target detection sensitivity (d′) for the same isochrony versus random timing contrast ([VAISO + VISO] > [VARAND + VRAND]). One data-point plotted per participant (n = 16) with the dashed line representing the robust-fit linear regression result. Individual peak sensory task-related voxel MNI coordinates (x- and y-axis) are plotted in the central figure, collapsed in the z-axis, superimposed on a mean anatomical scan (at z = 3) for illustrative purposes. Please note that these sensory voxels were selected a priori, before examining the behavioral results; see main text.
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fig3: Positive linear relation between changes in performance and beta parameter estimates in sensory cortices for isochrony. Task-related peak voxels were identified in bilateral auditory (superior temporal gyrus, STG) and visual (occipital lobe) cortices per participant. Isochrony-induced voxel beta parameter change in (a) left and (b) right STG, or (c) left and (d) right occipital lobe are plotted against change in target detection sensitivity (d′) for the same isochrony versus random timing contrast ([VAISO + VISO] > [VARAND + VRAND]). One data-point plotted per participant (n = 16) with the dashed line representing the robust-fit linear regression result. Individual peak sensory task-related voxel MNI coordinates (x- and y-axis) are plotted in the central figure, collapsed in the z-axis, superimposed on a mean anatomical scan (at z = 3) for illustrative purposes. Please note that these sensory voxels were selected a priori, before examining the behavioral results; see main text.

Mentions: Task-related (experimental trials > ) peak voxels in bilateral visual (occipital lobe) and auditory (STG) cortices were identified for each participant (Table 2; Fig. 3) and beta parameter estimates extracted. There was a positive relation between change in behavioral performance (visual target d′) and change in activity in the right occipital lobe (Fig. 3d) and bilateral STG (Fig. 3a,b) for the main effect of timing (isochrony > random; Table 2). There was also a trend toward the same positive linear relation in left occipital cortex (Fig. 3c). Participants with a greater isochrony-induced improvement in performance displayed greater activity enhancement in both visual and auditory sensory cortices for the same contrast. To better understand the relation between visual task performance and auditory cortex responses, we repeated the robust-fit regression analysis with the trials separated according to presence or absence of the auditory tone ([VISO > VRAND]; [VAISO > VARAND]). The only remaining significant positive correlation in auditory cortex was observed for the right STG during the audiovisual conditions (slope = 1.51, step = −1.66, t15 = 3.0, P = 0.047).


Visual and audiovisual effects of isochronous timing on visual perception and brain activity.

Marchant JL, Driver J - Cereb. Cortex (2012)

Positive linear relation between changes in performance and beta parameter estimates in sensory cortices for isochrony. Task-related peak voxels were identified in bilateral auditory (superior temporal gyrus, STG) and visual (occipital lobe) cortices per participant. Isochrony-induced voxel beta parameter change in (a) left and (b) right STG, or (c) left and (d) right occipital lobe are plotted against change in target detection sensitivity (d′) for the same isochrony versus random timing contrast ([VAISO + VISO] > [VARAND + VRAND]). One data-point plotted per participant (n = 16) with the dashed line representing the robust-fit linear regression result. Individual peak sensory task-related voxel MNI coordinates (x- and y-axis) are plotted in the central figure, collapsed in the z-axis, superimposed on a mean anatomical scan (at z = 3) for illustrative purposes. Please note that these sensory voxels were selected a priori, before examining the behavioral results; see main text.
© Copyright Policy - creative-commons
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3643713&req=5

fig3: Positive linear relation between changes in performance and beta parameter estimates in sensory cortices for isochrony. Task-related peak voxels were identified in bilateral auditory (superior temporal gyrus, STG) and visual (occipital lobe) cortices per participant. Isochrony-induced voxel beta parameter change in (a) left and (b) right STG, or (c) left and (d) right occipital lobe are plotted against change in target detection sensitivity (d′) for the same isochrony versus random timing contrast ([VAISO + VISO] > [VARAND + VRAND]). One data-point plotted per participant (n = 16) with the dashed line representing the robust-fit linear regression result. Individual peak sensory task-related voxel MNI coordinates (x- and y-axis) are plotted in the central figure, collapsed in the z-axis, superimposed on a mean anatomical scan (at z = 3) for illustrative purposes. Please note that these sensory voxels were selected a priori, before examining the behavioral results; see main text.
Mentions: Task-related (experimental trials > ) peak voxels in bilateral visual (occipital lobe) and auditory (STG) cortices were identified for each participant (Table 2; Fig. 3) and beta parameter estimates extracted. There was a positive relation between change in behavioral performance (visual target d′) and change in activity in the right occipital lobe (Fig. 3d) and bilateral STG (Fig. 3a,b) for the main effect of timing (isochrony > random; Table 2). There was also a trend toward the same positive linear relation in left occipital cortex (Fig. 3c). Participants with a greater isochrony-induced improvement in performance displayed greater activity enhancement in both visual and auditory sensory cortices for the same contrast. To better understand the relation between visual task performance and auditory cortex responses, we repeated the robust-fit regression analysis with the trials separated according to presence or absence of the auditory tone ([VISO > VRAND]; [VAISO > VARAND]). The only remaining significant positive correlation in auditory cortex was observed for the right STG during the audiovisual conditions (slope = 1.51, step = −1.66, t15 = 3.0, P = 0.047).

Bottom Line: Visual isochrony activated a similar timing-related brain network to that previously found primarily in auditory beat perception work.Finally, activity in multisensory left posterior superior temporal sulcus increased specifically during concurrent isochronous audiovisual presentations.These results indicate that regular isochronous timing can modulate visual processing and this can also involve multisensory audiovisual brain mechanisms.

View Article: PubMed Central - PubMed

Affiliation: Wellcome Trust Centre for Neuroimaging, UCL Institute of Neurology, London WC1N 3BG, UK. jennifer.marchant@ucl.ac.uk

ABSTRACT
Understanding how the brain extracts and combines temporal structure (rhythm) information from events presented to different senses remains unresolved. Many neuroimaging beat perception studies have focused on the auditory domain and show the presence of a highly regular beat (isochrony) in "auditory" stimulus streams enhances neural responses in a distributed brain network and affects perceptual performance. Here, we acquired functional magnetic resonance imaging (fMRI) measurements of brain activity while healthy human participants performed a visual task on isochronous versus randomly timed "visual" streams, with or without concurrent task-irrelevant sounds. We found that visual detection of higher intensity oddball targets was better for isochronous than randomly timed streams, extending previous auditory findings to vision. The impact of isochrony on visual target sensitivity correlated positively with fMRI signal changes not only in visual cortex but also in auditory sensory cortex during audiovisual presentations. Visual isochrony activated a similar timing-related brain network to that previously found primarily in auditory beat perception work. Finally, activity in multisensory left posterior superior temporal sulcus increased specifically during concurrent isochronous audiovisual presentations. These results indicate that regular isochronous timing can modulate visual processing and this can also involve multisensory audiovisual brain mechanisms.

Show MeSH
Related in: MedlinePlus