Table 1. Definitions of variables.
Raw images of light intensity over time as captured by the camera. | |
Detrended images of light intensity over time. | |
Mean value of each pixel’s time course. | |
Standard deviation of each pixel’s time course (after detrending). | |
Boolean pixel mask for saturation, | |
where included pixels have a value of 1 and saturated pixels 0. | |
Boolean pixel mask for signal-to-noise, | |
where included pixels have a value of 1 and low SNR pixels 0. | |
Boolean pixel mask for local correlation, | |
where included pixels have a value of 1 and low local correlation pixels 0. | |
Combination Boolean mask using the three masks: | |
, , and . | |
Manual segmentation. | |
Guided segmentation. | |
Masking parameter for SNR mask. | |
Masking parameter for correlation mask. | |
Images of changes in the absorption coefficient over time. | |
Optical pathlength. | |
Spatial Gaussian smoothing kernel. | |
Spatially-smoothed images of changes in the absorption coefficient over time.a | |
Number of pixels included in each pixel’s interpolation after smoothing. | |
Guided segmentation interpolated by smoothing. | |
Global signal averaged over the segmented brain.a | |
Regression coefficient at each pixel for the global signal.a | |
Images of changes in the absorption coefficient over time | |
after spatial smoothing and global signal regression.a | |
Matrix of correlation coefficients. | |
Boolean mask for correlation coefficient matrix. | |
Matrix of Fisher-transformed correlation coefficients. |
The subscript i denotes the segmentation method.