Affective matching of odors and facial expressions in infants: shifting patterns between 3 and 7 months

Abstract

Recognition of emotional facial expressions is a crucial skill for adaptive behavior. Past research suggests that at 5 to 7 months of age, infants look longer to an unfamiliar dynamic angry/happy face which emotionally matches a vocal expression. This suggests that they can match stimulations of distinct modalities on their emotional content. In the present study, olfaction-vision matching abilities were assessed across different age groups (3, 5 and 7 months) using dynamic expressive faces (happy vs. disgusted) and distinct hedonic odor contexts (pleasant, unpleasant and control) in a visual-preference paradigm. At all ages the infants were biased toward the disgust faces. This visual bias reversed into a bias for smiling faces in the context of the pleasant odor context in the 3-month-old infants. In infants aged 5 and 7 months, no effect of the odor context appeared in the present conditions. This study highlights the role of the olfactory context in the modulation of visual behavior toward expressive faces in infants. The influence of olfaction took the form of a contingency effect in 3-month-old infants, but later evolved to vanish or to take another form that could not be evidenced in the present study.

When preschoolers follow their eyes and older children follow their noses: visuo‐olfactory social affective matching in childhood

“…Multi‐sensory integration processing follows a ‘motor hierarchy’ (for a review, see Burr & Gori, ). For example, integration that relies on orienting reflexes (e.g., reflexive eye and hand movements) develops quite early (Bahrick & Lickliter, ; Godard et al., ; Kuhl & Meltzoff, ; Sann & Streri, ), while other forms of integration that rely on non‐reflexive, explicit motor responses continue to develop throughout childhood (Gori et al., ; Nardini et al., ; Nardini et al., ). To test the developmental trajectory of explicit, non‐reflexive visuo‐olfactory affective matching, we measured a goal‐directed motor response (e.g., pointing).…”

Food-Induced Emotional Resonance Improves Emotion Recognition

“…However, the process of recognizing emotional facial expressions relies not only on visual exteroceptive information, but also on non-visual interoceptive signals arising from the observer’s own internal states [39,40]. Interestingly, food-mood interactions have been widely investigated and the effects of different food substances on emotional states have been consistently demonstrated [23], providing clear evidence that taste and odours are strong and reliable elicitors of emotional reactions and the related facial expressions [22,41,42]. For example, Macht and Dettmer demonstrated that participants’ positive mood increased after eating chocolate or an apple, with a stronger and longer-lasting effect after chocolate intake [24].…”

“…Recent studies on 3-month old infants showed that after the babies inhaled a pleasant odour—such as strawberry—they spent more time looking towards a happy face than a disgusted one [22]. According to Godard and colleagues, the odour might have elicited a pleasant feeling, eventually activating facial muscles normally recruited when displaying that positive emotional state.…”

“…The activation of emotion-specific facial muscles might have consequently boosted the automatic imitational system [43], whereby infants tend to always imitate the facial expressions presented in front of them. Therefore, it was suggested that the odour would have oriented the infants’ gaze towards the expression that was compatible with their “pre-mobilized” facial muscles [22]. …”

“…Food can robustly affect emotional states [22,23]. For example, participants reported increases in positive mood after eating chocolate or an apple [24].…”