Evaluation of emotional faces appearing in sequence and memory
Creators: name: Goldenberg, Amit
Publisher: name: Open Science Framework
Year: 2022
Subjects: subject: Social and Behavioral Sciences

description: In a previous pre-registered study (https://osf.io/ag8nv), we tested amplification in estimations of the average emotion expressed by a sequence of faces. Participants saw a sequence of 1-12 faces expressing varying degrees of emotion, from neutral to emotional. All the faces within a sequence were taken from either a neutral-to-positive or a neutral-to-negative sequence. The faces were randomly selected from a pool ranging in intensity from 1 (neutral) – 50 (emotional) leading to a Gaussian distribution of the average expressed emotion, with a mean of 25. After watching the sequence, participants were asked to estimate the average expressed emotion in the sequence. We found that participants tended to overestimate the average emotion expressed in the sequence compared to the actual mean. This overestimation of group emotion compared to actual group mean is what we call the “amplification effect”. We further found that increase in the number of faces led to a stronger amplification effect. Finally, we found that the effect for negative emotions was slightly stronger compared to positive emotions but that this difference between positive and negative emotions was not significant. However, in a previous set of studies that examined the amplification effect in perceptions of crowds’ emotions we did found greater amplification in the evaluation of negative faces, so we expect this difference to be small or non-significant. In the current study we set to investigate a potential mechanism for the amplification effect in sequential exposure. Based on the finding that faces displaying stronger emotions are remembered more successfully (Keightley, Chiew et al. 2011, Liu, Chen et al. 2014), we suspect that increased attention towards emotional intense pictures plays a role in the amplification effect. If participants remembered the emotionally intense faces in a sequence, it might bias their judgement of the average sequence emotion to be stronger than it actually was contributing to the amplification effect. In order to test if stronger memory of more intense faces is an underlying mechanism of the amplification effect, we decided to add a memory test into our paradigm. Thus, participants will go through both tests in a block design: first the amplification effect test then the memory test. The reason for that is that we fear that asking participants to remember and evaluate average emotions at the same trial would bias their perceptions. In both tests participants will see a sequence of faces in similar way as in the previous studies. The sequences for this study will consist of eight faces per trial, all displaying either all a range from neutral to negative emotions or from neutral to positive emotions. We decided to choose eight-face sequences, because on the one hand our analysis of the previous study showed a robust amplification effect in this sequence (mean difference 1.59 and standard deviation 0.49), but on the other hand 8 was still shorter than 12, thus making the experiment shorter. In the amplification test section, participants will be asked to estimate the average emotion expressed in the sequence. In the memory test section following the sequence of faces, participants will see two target faces, one from the sequence and one that was not in the presented sequence. Participants will then be asked to decide which a face was part of the displayed sequence. This question will be followed by a question of how certain they were about their choice. Both sections will have equal number of trials.