Hold on Tight! Linking Emotions and Actions in the Infant Brain

Abstract

By the end of the first year, infants use others' emotions to interpret events, integrate social cues and build expectations on how people should behave (e.g., through social referencing). Yet, little is known about the neural correlates of linking others' emotions to following actions. This priming study investigates 10-month-old infants' electrophysiological responses to happy and disgusted emotional displays toward novel objects (prime) and subsequent actions (pushing away or pulling objects closer; target). Event-related potentials from 30 infants showed neural responses associated with emotional processing of the prime, such as heightened attentional response (Nc) and greater cognitive processing (Pc) in response to happiness over disgust. The target action of pushing away objects elicited increased slow wave activity when following happiness. Additionally, a significant mu-rhythm desynchronization, indicating motor resonance, was observed for pulling objects closer when preceded by happiness. Theta activity was higher for pushing away objects, indexing this as an unexpected event. These findings indicate that by 10 months, infants attend to emotional cues and use these cues to form predictions about subsequent actions. These neural correlates of bridging emotions and actions before 12 months of life reveal early neural sensitivity for processing social cues in complex contexts.

Keywords: actions; electroencephalography; emotions; infant cognition; social referencing.

FIGURE 1

Trial structure and duration of inter‐trial intervals (ITI), priming videos (a. disgust; b. happiness; in both cases a reach only action was performed), inter‐stimuli intervals (ISI), neutral frame, and target frames (c. push; d. pull). One priming video and one target frame per trial were presented; two examples are given to indicate the stimuli presented under the different conditions. The actors' expression was neutral during both the neutral and the target frames, while their gaze in the priming videos was directed at the observer at the beginning of the video, then shifted to the object at the start of the movement and returned to the observer when the emotion was expressed.

FIGURE 2

ERPs in response to the emotional displays presented in the priming videos. (a) Negative deflection (Nc) in the 400–600‐ms latency interval in the frontal (left panel) and frontocentral (right panel) electrodes; (b) positive waveform (Pc) in the 600–1000 ms latency interval at central (left panel) and parietal (right panel) electrodes.

FIGURE 3

Mean amplitudes, for (a) frontal (b) central and (c) parietal electrodes for the two conditions (happiness and disgust). ***p < 0.001; **p < 0.01; *p < 0.05.

FIGURE 4

ERPs in response to the action displays (presented separately according to the preceding emotional display) presented in the target frames. (a) Negative deflection (Nc) in the 350–650 ms latency interval in the frontal (upper left panel) and central (upper right panel) electrodes; (b) late slow wave (LSW) in the 800–1100 ms in all ROI.

FIGURE 5

Mean amplitudes for the pull and push actions at (a) frontal, (b) frontocentral and (c) central electrodes. (d) Mean amplitudes at parietal electrodes for the four conditions. ***p < 0.001; **p < 0.01; *p < 0.05.

FIGURE 6

Time‐frequency plots for the four conditions for the central electrodes (left: C3, middle: Cz, right: C4). The white rectangles show the selected time window (100–400 ms) for the alpha band analyzed (6–9 Hz).

FIGURE 7

Mean amplitude at the central electrodes for the two conditions (pull and push) in the alpha band. ***p < 0.001; **p < 0.01; *p < 0.05.