Developmental changes in the categorical processing of positive and negative facial expressions

Abstract

Categorical biases in the processing of emotional facial expression have been the subject of much debate in the literature. Opposing views on this topic claim either that positive or negative facial expressions enjoy improved processing in the human brain. The developmental changes in the processing advantages of positive and negative facial expressions are also disputed, with studies using varying paradigms showing seemingly contradictory results. Therefore, to further investigate the development of categorical processing and extraction of emotional information from faces, we tested 6-, 9-, and 12-year-old children, as well as adults, on their ability to categorize various facial expressions as positive or negative as quickly as possible. This was a simplified paradigm designed to explicitly contrast the processing efficiency of positive and negative facial expressions on the broader level of those emotional valence categories, rather than specific single emotional expressions. Our results show an early age processing advantage for positive facial expressions, which disappears in adults who show no such differences in the case of response time measures. In the case of accuracy measures, the early advantage for positive facial expressions gradually disappears and is reversed into a negativity advantage in adults. These findings demonstrate that category-based positive and negative processing advantages are strongly modulated by age over the course of development, and can exhibit opposite effects depending on the developmental stage of the participant.

The Role of Emotional Valence for the Processing of Facial and Verbal Stimuli—Positivity or Negativity Bias?

“…The overview of these studies therefore offers some hints that age might in fact play a role in the appearance of positivity and negativity biases. This finding is also supported by the results of a positive/negative face-categorization experiment (Vesker et al, 2018a), where the authors found an initial positivity bias with younger children, but which gradually disappeared, and in some cases even reversed into a negativity bias with increasing age.…”

“…After checking ~400 titles and abstracts, four studies could be identified that report valence effects in both modalities along the criteria mentioned above (see Table 1). In these studies, valence effects in adult populations either did not appear at all (Rellecke et al, 2011, accuracy outcomes in Bahn et al, 2017; Vesker et al, 2018a), converged for words and faces (judgement task in Feyereisen et al, 1986), or a valence effect was found in one modality, while no effect of valence emerged in the other modality (categorization task in Feyereisen et al, 1986; Schacht and Sommer, 2009, reaction time outcomes in Bahn et al, 2017; Vesker et al, 2018a).…”

“…In contrast, results from the emotional categorization task, where valence was clearly task-relevant, positive words were processed faster than negative words, whereas there was no valence effect for faces. In two parallel studies using a categorization task for audibly presented words (Bahn et al, 2017) and photographs of faces (Vesker et al, 2018a) participants were asked to categorize stimuli as positive or negative as quickly as possible. While the adult groups categorized positive and negative stimuli of both modalities at the same accuracy level, there was a modality effect for reaction times: Adults showed no valence effect for words, but a negativity advantage for faces.…”

“…This, in turn, leads to the predominant detection of a positivity bias, as described earlier in our review. In fact, the single exception to this tendency was in the study (Vesker et al, 2018a) where participants were deliberately only instructed to classify faces as positive or negative, rather than involving the individual emotions included in the stimulus set, thus avoiding the confounding effect of greater heterogeneity within the negative emotional category for facial expressions. However, even in this study, the negativity effect was found only in adult participants, while all three age groups of children showed a positivity advantage.…”

Investigating the Effects of Embodiment on Emotional Categorization of Faces and Words in Children and Adults

“…The results of our experiments reproduced the early positivity bias for words and faces reported by earlier studies using the same valence-based emotional categorization task (Bahn et al, 2017b;Vesker et al, 2018a), wherein younger children tended to show faster and more accurate responses to positive stimuli versus negative stimuli, with this positive/negative disparity diminishing with increasing age. However, we did not detect any significant effects of embodiment on the categorization of either faces (Experiment 1a) or words (Experiment 2) using the manipulation of facial musculature to either facilitate or inhibit smiling based on the original "pen-in-the-mouth" approach described by Strack et al (1988).…”