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Keeping in touch with the visual system: spatial alignment and multisensory integration of visual-somatosensory inputs.

Mahoney JR, Molholm S, Butler JS, Sehatpour P, Gomez-Ramirez M, Ritter W, Foxe JJ - Front Psychol (2015)

Bottom Line: In support, electrophysiological results revealed significant differences between multisensory simultaneous VS and summed V + S responses, regardless of the spatial alignment of the constituent inputs.Nonetheless, multisensory effects were earlier in the aligned conditions, and were found to be particularly robust in the case of right-sided inputs (beginning at just 55 ms).In contrast to previous work on audio-visual and audio-somatosensory inputs, the current work suggests a degree of spatial specificity to the earliest detectable multisensory integrative effects in response to VS pairings.

View Article: PubMed Central - PubMed

Affiliation: The Cognitive Neurophysiology Laboratory, The Nathan S. Kline Institute for Psychiatric Research, Orangeburg NY, USA ; Division of Cognitive and Motor Aging, Department of Neurology, Albert Einstein College of Medicine, New York NY, USA.

ABSTRACT
Correlated sensory inputs coursing along the individual sensory processing hierarchies arrive at multisensory convergence zones in cortex where inputs are processed in an integrative manner. The exact hierarchical level of multisensory convergence zones and the timing of their inputs are still under debate, although increasingly, evidence points to multisensory integration (MSI) at very early sensory processing levels. While MSI is said to be governed by stimulus properties including space, time, and magnitude, violations of these rules have been documented. The objective of the current study was to determine, both psychophysically and electrophysiologically, whether differential visual-somatosensory (VS) integration patterns exist for stimuli presented to the same versus opposite hemifields. Using high-density electrical mapping and complementary psychophysical data, we examined multisensory integrative processing for combinations of visual and somatosensory inputs presented to both left and right spatial locations. We assessed how early during sensory processing VS interactions were seen in the event-related potential and whether spatial alignment of the visual and somatosensory elements resulted in differential integration effects. Reaction times to all VS pairings were significantly faster than those to the unisensory conditions, regardless of spatial alignment, pointing to engagement of integrative multisensory processing in all conditions. In support, electrophysiological results revealed significant differences between multisensory simultaneous VS and summed V + S responses, regardless of the spatial alignment of the constituent inputs. Nonetheless, multisensory effects were earlier in the aligned conditions, and were found to be particularly robust in the case of right-sided inputs (beginning at just 55 ms). In contrast to previous work on audio-visual and audio-somatosensory inputs, the current work suggests a degree of spatial specificity to the earliest detectable multisensory integrative effects in response to VS pairings.

No MeSH data available.


Test of the race model. Difference waves between actual values of multisensory VS conditions vs. the predicted values using Miller’s (1982) inequality are plotted. Any value greater than zero indicates a violation of the race model. The pink highlighted box depicts a violation of the race model in support for coactivation, and this violation was obtained in all four multisensory experimental conditions.
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Figure 2: Test of the race model. Difference waves between actual values of multisensory VS conditions vs. the predicted values using Miller’s (1982) inequality are plotted. Any value greater than zero indicates a violation of the race model. The pink highlighted box depicts a violation of the race model in support for coactivation, and this violation was obtained in all four multisensory experimental conditions.

Mentions: Using Miller’s (1982) inequality, we tested whether the RSE exceeded the statistical facilitation predicted by probability summation. The CP at each quantile was group-averaged separately for each stimulus condition to form a distribution that maintained the shape of the individuals’ data and was then compared to the model. Behavioral results from this study indicate that the race model was indeed violated (i.e., values greater than zero) in all four conditions over the first 30% of the grouped (n = 14) RT distribution (Figure 2).


Keeping in touch with the visual system: spatial alignment and multisensory integration of visual-somatosensory inputs.

Mahoney JR, Molholm S, Butler JS, Sehatpour P, Gomez-Ramirez M, Ritter W, Foxe JJ - Front Psychol (2015)

Test of the race model. Difference waves between actual values of multisensory VS conditions vs. the predicted values using Miller’s (1982) inequality are plotted. Any value greater than zero indicates a violation of the race model. The pink highlighted box depicts a violation of the race model in support for coactivation, and this violation was obtained in all four multisensory experimental conditions.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4525670&req=5

Figure 2: Test of the race model. Difference waves between actual values of multisensory VS conditions vs. the predicted values using Miller’s (1982) inequality are plotted. Any value greater than zero indicates a violation of the race model. The pink highlighted box depicts a violation of the race model in support for coactivation, and this violation was obtained in all four multisensory experimental conditions.
Mentions: Using Miller’s (1982) inequality, we tested whether the RSE exceeded the statistical facilitation predicted by probability summation. The CP at each quantile was group-averaged separately for each stimulus condition to form a distribution that maintained the shape of the individuals’ data and was then compared to the model. Behavioral results from this study indicate that the race model was indeed violated (i.e., values greater than zero) in all four conditions over the first 30% of the grouped (n = 14) RT distribution (Figure 2).

Bottom Line: In support, electrophysiological results revealed significant differences between multisensory simultaneous VS and summed V + S responses, regardless of the spatial alignment of the constituent inputs.Nonetheless, multisensory effects were earlier in the aligned conditions, and were found to be particularly robust in the case of right-sided inputs (beginning at just 55 ms).In contrast to previous work on audio-visual and audio-somatosensory inputs, the current work suggests a degree of spatial specificity to the earliest detectable multisensory integrative effects in response to VS pairings.

View Article: PubMed Central - PubMed

Affiliation: The Cognitive Neurophysiology Laboratory, The Nathan S. Kline Institute for Psychiatric Research, Orangeburg NY, USA ; Division of Cognitive and Motor Aging, Department of Neurology, Albert Einstein College of Medicine, New York NY, USA.

ABSTRACT
Correlated sensory inputs coursing along the individual sensory processing hierarchies arrive at multisensory convergence zones in cortex where inputs are processed in an integrative manner. The exact hierarchical level of multisensory convergence zones and the timing of their inputs are still under debate, although increasingly, evidence points to multisensory integration (MSI) at very early sensory processing levels. While MSI is said to be governed by stimulus properties including space, time, and magnitude, violations of these rules have been documented. The objective of the current study was to determine, both psychophysically and electrophysiologically, whether differential visual-somatosensory (VS) integration patterns exist for stimuli presented to the same versus opposite hemifields. Using high-density electrical mapping and complementary psychophysical data, we examined multisensory integrative processing for combinations of visual and somatosensory inputs presented to both left and right spatial locations. We assessed how early during sensory processing VS interactions were seen in the event-related potential and whether spatial alignment of the visual and somatosensory elements resulted in differential integration effects. Reaction times to all VS pairings were significantly faster than those to the unisensory conditions, regardless of spatial alignment, pointing to engagement of integrative multisensory processing in all conditions. In support, electrophysiological results revealed significant differences between multisensory simultaneous VS and summed V + S responses, regardless of the spatial alignment of the constituent inputs. Nonetheless, multisensory effects were earlier in the aligned conditions, and were found to be particularly robust in the case of right-sided inputs (beginning at just 55 ms). In contrast to previous work on audio-visual and audio-somatosensory inputs, the current work suggests a degree of spatial specificity to the earliest detectable multisensory integrative effects in response to VS pairings.

No MeSH data available.