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Variability in prefrontal hemodynamic response during exposure to repeated self-selected music excerpts, a near-infrared spectroscopy study.

Moghimi S, Schudlo L, Chau T, Guerguerian AM - PLoS ONE (2015)

Bottom Line: Music-induced brain activity modulations in areas involved in emotion regulation may be useful in achieving therapeutic outcomes.Based on spatial and temporal characteristics of these observed hemodynamic changes, we defined a consistency index to represent variability across these domains.Consistency indexes were significantly different for identical versus non-identical musical excerpts when comparing a subset of repetitions.

View Article: PubMed Central - PubMed

Affiliation: University of Toronto, Toronto, Ontario, Canada; Hospital for Sick Children Research Institute, Toronto, Ontario, Canada.

ABSTRACT
Music-induced brain activity modulations in areas involved in emotion regulation may be useful in achieving therapeutic outcomes. Clinical applications of music may involve prolonged or repeated exposures to music. However, the variability of the observed brain activity patterns in repeated exposures to music is not well understood. We hypothesized that multiple exposures to the same music would elicit more consistent activity patterns than exposure to different music. In this study, the temporal and spatial variability of cerebral prefrontal hemodynamic response was investigated across multiple exposures to self-selected musical excerpts in 10 healthy adults. The hemodynamic changes were measured using prefrontal cortex near infrared spectroscopy and represented by instantaneous phase values. Based on spatial and temporal characteristics of these observed hemodynamic changes, we defined a consistency index to represent variability across these domains. The consistency index across repeated exposures to the same piece of music was compared to the consistency index corresponding to prefrontal activity from randomly matched non-identical musical excerpts. Consistency indexes were significantly different for identical versus non-identical musical excerpts when comparing a subset of repetitions. When all four exposures were compared, no significant difference was observed between the consistency indexes of randomly matched non-identical musical excerpts and the consistency index corresponding to repetitions of the same musical excerpts. This observation suggests the existence of only partial consistency between repeated exposures to the same musical excerpt, which may stem from the role of the prefrontal cortex in regulating other cognitive and emotional processes.

No MeSH data available.


Related in: MedlinePlus

Point representation of similarity topographies.For each musical excerpt, the six similarity topographies were represented using points with (x,y,z) coordinates. The three dimensional distribution of these points are shown for the representative similarity topographies. The distribution of the points in space corresponded to the consistency of the similarity topographies (i.e. points corresponding to similar topographies are closer in the three dimensional space on the right). The point coordinates were normalized to facilitate representation, in this figure.
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pone.0122148.g004: Point representation of similarity topographies.For each musical excerpt, the six similarity topographies were represented using points with (x,y,z) coordinates. The three dimensional distribution of these points are shown for the representative similarity topographies. The distribution of the points in space corresponded to the consistency of the similarity topographies (i.e. points corresponding to similar topographies are closer in the three dimensional space on the right). The point coordinates were normalized to facilitate representation, in this figure.

Mentions: In order to compare the six similarity topographies, an image moment and the center of mass was determined. For each similarity topography the center of mass was a weighted average of the pixel values with the weights equal to the pixel value. This value represented the distribution of the observed activity across the forehead area. The image moments were determined using Tchebichef polynomials [20]. This method enables compact image representation and has been successfully used for spatial characterization of the prefrontal NIRS in previous studies [21–22]. The order of the image moment was 20. This value was determined empirically by observing the distribution of the moments corresponding to different similarity topographies. Consequently each similar topography was represented by points corresponding to horizontal and vertical coordinates of the center of mass and the moment value. The distribution of these points in the three dimensional space represented the consistency between repetitions of the same musical excerpt. More scattered distributions corresponded to more spatiotemporal variability between repetitions, while more condensed distributions pointed to more consistency among the different repetitions of the musical excerpt. Fig. 4 depicts the steps leading to the three dimensional representation of the similarity topographies.


Variability in prefrontal hemodynamic response during exposure to repeated self-selected music excerpts, a near-infrared spectroscopy study.

Moghimi S, Schudlo L, Chau T, Guerguerian AM - PLoS ONE (2015)

Point representation of similarity topographies.For each musical excerpt, the six similarity topographies were represented using points with (x,y,z) coordinates. The three dimensional distribution of these points are shown for the representative similarity topographies. The distribution of the points in space corresponded to the consistency of the similarity topographies (i.e. points corresponding to similar topographies are closer in the three dimensional space on the right). The point coordinates were normalized to facilitate representation, in this figure.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4383450&req=5

pone.0122148.g004: Point representation of similarity topographies.For each musical excerpt, the six similarity topographies were represented using points with (x,y,z) coordinates. The three dimensional distribution of these points are shown for the representative similarity topographies. The distribution of the points in space corresponded to the consistency of the similarity topographies (i.e. points corresponding to similar topographies are closer in the three dimensional space on the right). The point coordinates were normalized to facilitate representation, in this figure.
Mentions: In order to compare the six similarity topographies, an image moment and the center of mass was determined. For each similarity topography the center of mass was a weighted average of the pixel values with the weights equal to the pixel value. This value represented the distribution of the observed activity across the forehead area. The image moments were determined using Tchebichef polynomials [20]. This method enables compact image representation and has been successfully used for spatial characterization of the prefrontal NIRS in previous studies [21–22]. The order of the image moment was 20. This value was determined empirically by observing the distribution of the moments corresponding to different similarity topographies. Consequently each similar topography was represented by points corresponding to horizontal and vertical coordinates of the center of mass and the moment value. The distribution of these points in the three dimensional space represented the consistency between repetitions of the same musical excerpt. More scattered distributions corresponded to more spatiotemporal variability between repetitions, while more condensed distributions pointed to more consistency among the different repetitions of the musical excerpt. Fig. 4 depicts the steps leading to the three dimensional representation of the similarity topographies.

Bottom Line: Music-induced brain activity modulations in areas involved in emotion regulation may be useful in achieving therapeutic outcomes.Based on spatial and temporal characteristics of these observed hemodynamic changes, we defined a consistency index to represent variability across these domains.Consistency indexes were significantly different for identical versus non-identical musical excerpts when comparing a subset of repetitions.

View Article: PubMed Central - PubMed

Affiliation: University of Toronto, Toronto, Ontario, Canada; Hospital for Sick Children Research Institute, Toronto, Ontario, Canada.

ABSTRACT
Music-induced brain activity modulations in areas involved in emotion regulation may be useful in achieving therapeutic outcomes. Clinical applications of music may involve prolonged or repeated exposures to music. However, the variability of the observed brain activity patterns in repeated exposures to music is not well understood. We hypothesized that multiple exposures to the same music would elicit more consistent activity patterns than exposure to different music. In this study, the temporal and spatial variability of cerebral prefrontal hemodynamic response was investigated across multiple exposures to self-selected musical excerpts in 10 healthy adults. The hemodynamic changes were measured using prefrontal cortex near infrared spectroscopy and represented by instantaneous phase values. Based on spatial and temporal characteristics of these observed hemodynamic changes, we defined a consistency index to represent variability across these domains. The consistency index across repeated exposures to the same piece of music was compared to the consistency index corresponding to prefrontal activity from randomly matched non-identical musical excerpts. Consistency indexes were significantly different for identical versus non-identical musical excerpts when comparing a subset of repetitions. When all four exposures were compared, no significant difference was observed between the consistency indexes of randomly matched non-identical musical excerpts and the consistency index corresponding to repetitions of the same musical excerpts. This observation suggests the existence of only partial consistency between repeated exposures to the same musical excerpt, which may stem from the role of the prefrontal cortex in regulating other cognitive and emotional processes.

No MeSH data available.


Related in: MedlinePlus