Spatial and viewpoint selectivity for others' observed actions in monkey ventral premotor mirror neurons

Area of Science:

• Neuroscience
• Primatology
• Cognitive Science

Background:

• Observed actions' spatial location and viewpoint are linked in natural settings.
• Mirror neurons (MNs) in the monkey ventral premotor area F5 are known to code spatial location and be modulated by viewpoint.
• The integration of viewpoint and spatial location by MNs during live action observation is not well understood.

Purpose of the Study:

• To investigate whether and to what extent mirror neurons integrate viewpoint and spatial location of live observed actions.
• To compare the activity of F5 MNs under different combinations of viewpoint and spatial location during action observation.

Main Methods:

• Recorded activity of 148 F5 MNs in macaque monkeys.
• Monkeys observed an experimenter grasping actions from lateral views in extrapersonal and peripersonal space, and a subjective view in peripersonal space.
• Analyzed single-neuron and population-level activity for space and viewpoint selectivity.

Main Results:

• A majority of MNs (60.8%) were space-selective.
• Space-selective MNs preferring peripersonal space showed a preference for the subjective viewpoint.
• Space-unselective neurons demonstrated viewpoint invariance.

Conclusions:

• Mirror neurons exhibit integrated spatial and viewpoint selectivity during live action observation.
• A previously uncharacterized link between spatial coding and viewpoint selectivity in F5 MNs was revealed.
• Findings contribute to understanding neural mechanisms of action perception and social cognition.