Empathy became a fashionable phenomenon to study with imaging techniques, but the use of such techniques may impact on the phenomenon being studied. To assess whether the original concept has changed or whether the adoption of particular techniques modify the conception of empathy, we endorsed empathy for human pain as a paradigm, and reviewed studies of empathy in the neurosciences, analysing the way the concept of empathy varies in the various studies and how this affects results.
We performed PubMed, PsycLit and Embase searches using the subset “empathy” and “pain” as keywords and crossing it with each of various functional imaging techniques (PET, fMRI, SPECT, rTMS and the like). We included all experimental studies performed with an adequate design and sample size allowing to support their results and measuring empathy.
The concept of empathy has changed across centuries, moving from a philosophical standpoint to a psychological one, and eventually to current neurophysiology. It oscillates between an automatic and preconscious phenomenon to one influenced by drives, beliefs and expectations. Empathy appears to have both top-down and bottom-up arms.
Empathy is not a unitary phenomenon, but it encompasses various concepts. A fragmentation ensues that affects experimental protocols, thus in turn influencing the obtained results.