Fig. 8.

Comparison of (a) coefficient (beta) and (b) $t$-statistics for the offline (AR-IRLS) and online (Kalman) analysis methods across all channels of ${\mathrm{HbO}}_2$ for all subjects using varying lengths of the time-series data from 1 to 5 min. Each point indicated by a “$+$” symbol represents a source–detector pair for one of the subjects and for one of the conditions (sway or fixed platform). The solid black line indicates regression line indicating the relationship between the online Kalman estimates and the offline AR-IRLS estimates. The dashed red line indicates the ideal regression line with a slope of one. A difference in slopes between the red and black lines indicates systematic difference between the two estimators.