Representation of the observer's predicted outcome value in mirror and nonmirror neurons of macaque F5 ventral premotor cortex

Non-shared coding of observed and executed actions prevails in macaque ventral premotor mirror neurons

According to the mirror mechanism the discharge of F5 mirror neurons of a monkey observing another individual performing an action is a motor representation of the observed action that may serve to understand or learn from the action. This hypothesis, if strictly interpreted, requires mirror neurons to exhibit an action tuning that is shared between action observation and execution. Due to insufficient data it remains contentious if this requirement is met. To fill in the gaps, we conducted an experiment in which identical objects had to be manipulated in three different ways in order to serve distinct action goals. Using three methods, including cross-task classification, we found that at most time points F5 mirror neurons did not encode observed actions with the same code underlying action execution. However, in about 20% of neurons there were time periods with a shared code. These time periods formed a distinct cluster and cannot be considered a product of chance. Population classification yielded non-shared coding for observed actions in the whole population, which was at times optimal and consistently better than shared coding in differentially selected subpopulations. These results support the hypothesis of a representation of observed actions based on a strictly defined mirror mechanism only for small subsets of neurons and only under the assumption of time-resolved readout. Considering alternative concepts and recent findings, we propose that during observation mirror neurons represent the process of a goal pursuit from the observer's viewpoint. Whether the observer's goal pursuit, in which the other's action goal becomes the observer's action goal, or the other's goal pursuit is represented remains to be clarified. In any case, it may allow the observer to use expectations associated with a goal pursuit to directly intervene in or learn from another's action.

Brain solutions for hearing problems during the COVID-19 pandemic and the misery of wearing a mask

BACKGROUND

In COVID-19 pandemics days, wearing facial mask in public places has become obligatory to prevent the virus spread. In addition to its valuable protection, wearing facial mask can affect verbal communication in an adverse fashion and makes mutual understanding difficult. This happens because the mask eliminates the positive effect of the lip-reading phenomenon in direct communications. The mirror neuron system is responsible for automatic imitation, associative sequence learning, and motor mimicry. This system is a strong candidate justifying an unexpected action described in this article.

PURPOSE

Taking the facial mask off, to help the listener understanding better is a normal reaction. However, unexpectedly, one does the same as the listener when he/she is unable to comprehend the speaker. Herein, we suggest a hypothesis proposing the basic role of Mirror neuron system in this action. Most of the research on these cells have been conducted on monkeys, where the researchers observed that, these neuron discharge pulses both when a monkey performs an action and when it observes another monkey or a person committing the similar action.

CONCLUSION

The driving mechanism of an unanticipated action of taking off mask while listening to a speaker is emphasized in this paper. Herein, we try to clarify how we came up with the idea that mirror neuron system drives a surprising action observed in COVID-19 pandemics days. As a result, we suggest possible clinical studies to verify our hypothesis.