Action priming with biomechanically possible and impossible grasps: ERP evidence from 6-month-old infants

Abstract

Coding the direction of others' gestures is a fundamental human ability, since it allows the observer to attend and react to sources of potential interest in the environment. Shifts of attention triggered by action observation have been reported to occur early in infancy. Yet, the neurophysiological underpinnings of such action priming and the properties of gestures that might be crucial for it remain unknown. Here, we addressed these issues by recording electroencephalographic activity (EEG) from 6-month-old infants cued with spatially non-predictive hand grasping toward or away from the position of a target object, i.e., valid and invalid trials, respectively. Half of the infants were cued with a gesture executable by a human hand (possible gesture) and the other half with a gesture impossible to be executed by a human hand. Results show that the amplitude enhancement of the posterior N290 component in response to targets in valid trials, as compared to invalid trials, was present only for infants seeing possible gestures, while it was absent for infants seeing impossible gestures. These findings suggest that infants detect the biomechanical properties of human movements when processing hand gestures, relying on this information to orient their visual attention toward the target object.

The neural correlates of orienting to walking direction in 6‐month‐old infants: An ERP study

“…Studies carried out with this paradigm have revealed that the temporoparietal component N290 is sensitive to congruency relations starting from 9 months of age (Senju et al, ). Similar results were found in 6‐month‐old infants, using a cueing paradigm where the target presentation was preceded by the presentation of a dynamic possible or impossible hand gesture (Natale et al, ). Results indicate that the N290 component is modulated by congruency relations between cue and target but only when the cue represents a possible hand gesture and not when the cue represents an impossible hand gesture.…”

“…A cueing paradigm was employed (Natale et al, ; Posner, ). As shown in Figure , each trial began with a visually animated but silent fixation point, (i.e., attention getter) randomly selected among 16 different animations, displayed at the center of the screen.…”

“…Humans are able to encode the direction of human gestures and to use these as a cue to orient their own visuospatial attention. It has been demonstrated that, early in life, humans orient their attention toward the portion of the environment signaled by conspecifics' gestures and actions (Gredebäck & Daum, ; Natale et al, ). This evidence indicates that infants can use others' gestures as relevant cues to detect and orient to potentially salient information in the environment.…”

“…() was adopted and coupled with the recording of the EEG signal. As in previous behavioral and EEG infants' studies (i.e., Bardi et al, ; Farroni et al, ; Natale et al, ), in the following experiment only congruent and incongruent trials were presented. In the absence of neutral trials, facilitatory and inhibitory effects are confounded.…”

Speech Intonation Induces Enhanced Face Perception in Infants

“…The difference between the two experiments at the early processing stages -as indexed by the P1 and N290 components -speaks against one common process. Though both the P1 38 and the N290 37,39 have been found in studies on infants' attention, in our study the stimuli between the two experiments are matched pixel by pixel but differ in their psychological meaning: human (upright) faces are special stimuli from at least birth 3,40 . Our results suggest that the P1 and N290 are neural correlates of different processes, rather than just different aspects of the same (attentional) process, with the N290 being a well-studied correlate of face perception in infants.…”