Power modulation of electroencephalogram mu and beta frequency depends on perceived level of observed actions

Abstract

IntroductionThe ability to understand actions and intentions of others is of great importance to social relationships and is associated with the mirror neuron system of the human brain. Whether conscious perception of specific actions is necessary to trigger activity in this system, or alternatively whether this response is independent of conscious perception is not known.MethodsWe addressed this issue by rendering videos of right hand movements invisible to conscious perception, and measuring electroencephalogram (EEG) power suppression in the mu (8–13 Hz) and beta (15–25 Hz) range as index corresponding to the magnitude of mirror neuron activity.ResultsIn the beta range over bilateral sensorimotor sites, we find that suppression indices follow the reported perceptual level of subjects with stronger suppression for consciously perceived trials. Furthermore, in the nonperceived trials, oscillation power is significantly suppressed relative to baseline. In the low mu range (8–10 Hz), oscillation power over the left sensorimotor site is significantly more suppressed in the consciously perceived versus nonperceived trials.ConclusionsOur data suggest that the intensity of mirror system responses during action observation decreases with the observers' perception level yet remains significant during observation of invisible actions. Such subliminal activity could help explain phenomena such as covert imitation.

Investigating Mirror System (MS) Activity in Adults with ASD When Inferring Others’ Intentions Using Both TMS and EEG

“…No significant relationships were found between mu suppression in the 10–12 Hz frequency band and any other measures. These data support previous EEG studies which have found mu suppression in the lower alpha frequency band (8–10 Hz) but not the higher alpha frequency band during action observation (Cochin 1999 ; Simon and Mukamel 2016 ). These EEG data also support the functional segregation of mu rhythm into two discrete sub-bands, complimenting previous work that found distinct mu responses in low and high alpha bands (Dumas et al 2014 ; Frenkel-Toledo et al 2014 ; Neuper et al 2009 ; Pfurtscheller et al 2000 ).…”

Activity in primary motor cortex during action observation covaries with subsequent behavioral changes in execution

“…The changes in behavior we report are a result of implicit mimicry/contagion of the observed action and our whole‐brain fMRI results demonstrate that these implicit behavioral changes correlate with activity level in M1 during passive observation. This result is in agreement with our recent finding that visual presentation of actions that are not consciously perceived, is sufficient to elicit significant neural responses in frontal regions (Simon & Mukamel ). The current design does not allow determining which particular element of the observed action underlies these changes in behavior, however previous studies point to the importance of the presence of a biological agent in such effects (Avanzino et al., ; Kilner, Paulignan, & Blakemore, ).…”

“…This result is in agreement with our recent finding that visual presentation of actions that are not consciously perceived, is sufficient to elicit significant neural responses in frontal regions (Simon & Mukamel 2016). The current design does not allow determining which particular element of the observed action underlies these changes in behavior, however previous studies point to the importance of the presence of a biological agent in such effects (Avanzino et al, 2015;Kilner, Paulignan, & Blakemore, 2003).…”

EEG beta-power changes reflect motor involvement in abstract action language processing

“…The CA-value in the time slot for the noun represents the value for concrete nouns and the AA-value represents the value for abstract nouns. The Moreno et al (2013) and Simon and Mukamel (2016). In both studies, l-and b-ERD could be observed while participants were watching videos of hand movements.…”