Neural correlates of attentional orienting with neutral and fearful gaze cues in 12-month-olds.

Infants use information on gaze direction and facial expressions for social referencing when encountering various objects in their environment. However, it remains unclear how these social cues influence attentional orienting in infants. Using event-related potentials (ERPs), we investigated the neural correlates of attentional orienting cued by an averted gaze with neutral and fearful expressions in 12-month-olds. We focused on the ERPs in response to a face (N290, P400, and Nc) as well as a saccade toward the target (the presaccadic spike potential: SP) and found that the amplitudes of the face-sensitive ERPs (N290 and P400) were larger for directed than averted gaze direction irrespective of facial expression. Furthermore, the amplitude of the SP involved in overt orienting was larger for fearful expressions than for neutral expressions, irrespective of gaze congruency. These results suggest that information on gaze direction and facial expression, specifically neutral and fearful expressions, may be processed independently, and that fearful expressions dominantly influence the neural correlates of attentional orienting in infants around 12 months of age.

Rapid saccadic response with fearful gaze cue.

It has been shown that an averted gaze with emotional expression guides our attention toward a gazed-at location, and the effect of a gaze with fearful expression has been well-investigated. However, the findings are not consistent, and most studies used the manual response measure. Recent studies suggest that examining eye movements is more suitable to capture the early stage of the effect of threat-related stimuli on attentional process. Therefore, in the present study, we investigated the effects of static neutral and fearful gaze on overt attention orienting by examining the saccadic responses in an unselected sample of people. Our results found the gaze congruency effects for both expressions, and importantly, enhanced attention orienting by fearful gaze at a short stimulus onset asynchrony (SOA): participants looked faster at the fearful gaze-cued target than the neutral gaze-cued one at the 300 ms SOA. These findings provide the first evidence that fearful averted gaze elicits rapid overt attention orienting toward the target, and suggest that the information of gaze direction and emotional expression are rapidly integrated and modulate the oculomotor system.

Fearful gaze cueing: gaze direction and facial expression independently influence overt orienting responses in 12-month-olds.

Gaze direction cues and facial expressions have been shown to influence object processing in infants. For example, infants around 12 months of age utilize others' gaze directions and facial expressions to regulate their own behaviour toward an ambiguous target (i.e., social referencing). However, the mechanism by which social signals influence overt orienting in infants is unclear. The present study examined the effects of static gaze direction cues and facial expressions (neutral vs. fearful) on overt orienting using a gaze-cueing paradigm in 6- and 12-month-old infants. Two experiments were conducted: in Experiment 1, a face with a leftward or rightward gaze direction was used as a cue, and a face with a forward gaze direction was added in Experiment 2. In both experiments, an effect of facial expression was found in 12-month-olds; no effect was found in 6-month-olds. Twelve-month-old infants exhibited more rapid overt orienting in response to fearful expressions than neutral expressions, irrespective of gaze direction. These findings suggest that gaze direction information and facial expressions independently influence overt orienting in infants, and the effect of facial expression emerges earlier than that of static gaze direction. Implications for the development of gaze direction and facial expression processing systems are discussed.