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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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Auditory tone modulates impact of visual stimulus timing on pSTS ROI. (a) Multisensory ROI in left pSTS showed greater isochrony enhancement when visual stimuli were accompanied by a synchronous auditory tone (VA), but not when presented alone (V). (b) The 8-mm sphere ROI was centered at x = −54, y = −50, z = 8, a location previously identified to be modulated by temporal properties of long audiovisual stimulus steams (Noesselt et al. 2007; see also Marchant et al. 2011). By contrast, (c and d) whole brain analysis revealed a region in the right superior temporal gyrus (STG) that showed the opposite interaction pattern, with greater enhancement for random timing during the audiovisual (VA) than the vision-only (V) condition. (a and c) Group mean (±1 s.e.d. for isochrony effect) beta parameter values plotted for each condition (light bar = isochronous; dark bars = random). (b) Shows ROI; (d) shows significant cluster from whole-brain analysis. Both are displayed on the mean anatomical image. * = Significant post hoc paired t-test (P < 0.05).
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fig4: Auditory tone modulates impact of visual stimulus timing on pSTS ROI. (a) Multisensory ROI in left pSTS showed greater isochrony enhancement when visual stimuli were accompanied by a synchronous auditory tone (VA), but not when presented alone (V). (b) The 8-mm sphere ROI was centered at x = −54, y = −50, z = 8, a location previously identified to be modulated by temporal properties of long audiovisual stimulus steams (Noesselt et al. 2007; see also Marchant et al. 2011). By contrast, (c and d) whole brain analysis revealed a region in the right superior temporal gyrus (STG) that showed the opposite interaction pattern, with greater enhancement for random timing during the audiovisual (VA) than the vision-only (V) condition. (a and c) Group mean (±1 s.e.d. for isochrony effect) beta parameter values plotted for each condition (light bar = isochronous; dark bars = random). (b) Shows ROI; (d) shows significant cluster from whole-brain analysis. Both are displayed on the mean anatomical image. * = Significant post hoc paired t-test (P < 0.05).

Mentions: Whole brain analysis for the interaction contrast ([VAISO > VARAND] > [VISO > VRAND]) did not identify any regions showing a significantly greater isochrony enhancement in the audiovisual than vision-only condition. However, the a priori ROI in multisensory left pSTS previously identified to be modulated by audiovisual timing in Noesselt et al. (2007; 8-mm sphere centered at x = −54, y = −50, z = 8; Fig. 4b) did show a substantial trend toward an interaction effect (F1,15 = 3.6; P = 0.077) that is reported for completeness; as well as a significant main effect of timing (F1,15 = 6.3; P = 0.024). Post hoc t-tests confirmed that isochrony (vs. random timing) enhanced BOLD signal in left pSTS when visual stimuli were accompanied by an auditory tone (t15 = 3.7, P = 0.002) but not when presented alone (t15 = 0.5, P = 0.619, n.s.; Fig. 4a). Activity in left pSTS was highest during the multisensory isochronous condition than all others (VAISO > VISO: t15 = 2.3, P = 0.035; VAISO > VRAND: t15 = 2.1, P = 0.048). Activity in the ROI in right pSTS also showed a main effect of timing (F1,15 = 5.8; P = 0.029; ISO > RAND), but there was no trend toward an interaction with audiovisual synchrony (F1,15 = 0.2; P = 0.668, n.s.). This concurs with a left lateralisation for this multisensory integration site with centrally presented audiovisual stimuli (e.g., Calvert 2001; Macaluso et al. 2004).


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

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

Auditory tone modulates impact of visual stimulus timing on pSTS ROI. (a) Multisensory ROI in left pSTS showed greater isochrony enhancement when visual stimuli were accompanied by a synchronous auditory tone (VA), but not when presented alone (V). (b) The 8-mm sphere ROI was centered at x = −54, y = −50, z = 8, a location previously identified to be modulated by temporal properties of long audiovisual stimulus steams (Noesselt et al. 2007; see also Marchant et al. 2011). By contrast, (c and d) whole brain analysis revealed a region in the right superior temporal gyrus (STG) that showed the opposite interaction pattern, with greater enhancement for random timing during the audiovisual (VA) than the vision-only (V) condition. (a and c) Group mean (±1 s.e.d. for isochrony effect) beta parameter values plotted for each condition (light bar = isochronous; dark bars = random). (b) Shows ROI; (d) shows significant cluster from whole-brain analysis. Both are displayed on the mean anatomical image. * = Significant post hoc paired t-test (P < 0.05).
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Related In: Results  -  Collection

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fig4: Auditory tone modulates impact of visual stimulus timing on pSTS ROI. (a) Multisensory ROI in left pSTS showed greater isochrony enhancement when visual stimuli were accompanied by a synchronous auditory tone (VA), but not when presented alone (V). (b) The 8-mm sphere ROI was centered at x = −54, y = −50, z = 8, a location previously identified to be modulated by temporal properties of long audiovisual stimulus steams (Noesselt et al. 2007; see also Marchant et al. 2011). By contrast, (c and d) whole brain analysis revealed a region in the right superior temporal gyrus (STG) that showed the opposite interaction pattern, with greater enhancement for random timing during the audiovisual (VA) than the vision-only (V) condition. (a and c) Group mean (±1 s.e.d. for isochrony effect) beta parameter values plotted for each condition (light bar = isochronous; dark bars = random). (b) Shows ROI; (d) shows significant cluster from whole-brain analysis. Both are displayed on the mean anatomical image. * = Significant post hoc paired t-test (P < 0.05).
Mentions: Whole brain analysis for the interaction contrast ([VAISO > VARAND] > [VISO > VRAND]) did not identify any regions showing a significantly greater isochrony enhancement in the audiovisual than vision-only condition. However, the a priori ROI in multisensory left pSTS previously identified to be modulated by audiovisual timing in Noesselt et al. (2007; 8-mm sphere centered at x = −54, y = −50, z = 8; Fig. 4b) did show a substantial trend toward an interaction effect (F1,15 = 3.6; P = 0.077) that is reported for completeness; as well as a significant main effect of timing (F1,15 = 6.3; P = 0.024). Post hoc t-tests confirmed that isochrony (vs. random timing) enhanced BOLD signal in left pSTS when visual stimuli were accompanied by an auditory tone (t15 = 3.7, P = 0.002) but not when presented alone (t15 = 0.5, P = 0.619, n.s.; Fig. 4a). Activity in left pSTS was highest during the multisensory isochronous condition than all others (VAISO > VISO: t15 = 2.3, P = 0.035; VAISO > VRAND: t15 = 2.1, P = 0.048). Activity in the ROI in right pSTS also showed a main effect of timing (F1,15 = 5.8; P = 0.029; ISO > RAND), but there was no trend toward an interaction with audiovisual synchrony (F1,15 = 0.2; P = 0.668, n.s.). This concurs with a left lateralisation for this multisensory integration site with centrally presented audiovisual stimuli (e.g., Calvert 2001; Macaluso et al. 2004).

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