  This compendium review focuses on the spatial distribution of sensitivity to
localized absorption changes in optically diffuse media, particularly for
measurements relevant to near-infrared spectroscopy. The three temporal
domains, continuous-wave, frequency-domain, and time-domain, each obtain
different optical data-types whose changes may be related to effective
homogeneous changes in the absorption coefficient. Sensitivity is the
relationship between a localized perturbation and the recovered effective
homogeneous absorption change. Therefore, spatial sensitivity maps representing
the perturbation location can be generated for the numerous optical data-types
in the three temporal domains. The review first presents a history of the past
30 years of work investigating this sensitivity in optically diffuse media.
These works are experimental and theoretical, presenting 1-, 2-, and
3-dimensional sensitivity maps for different near-infrared spectroscopy
methods, domains, and data-types. Following this history, we present a
compendium of sensitivity maps organized by temporal domain and then data-type.
This compendium provides a valuable tool to compare the spatial sensitivity of
various measurement methods and parameters in one document. Methods for one to
generate these maps are provided in the appendix, including code. This
historical review and comprehensive sensitivity map compendium provides a
single source researchers may use to visualize, investigate, compare, and
generate sensitivity to localized absorption change maps.
