Expressions (raw: 68 , unbiased: 54 ) to high WP1066MedChemExpress WP1066 intensity expressions (raw: 75 , unbiased: 63 ) of the ADFES-BIV is in line with previous research from morphed static stimuli looking at varying intensities where accuracy was linearly associated with physical expression intensity (see [44]) and has been shown for the first time from dynamic stimuli, i.e. video recordings. The lower response times in higher intensities support the notion that responding occurs more rapidly the easier a stimulus is to recognise [28]. The intensity of the muscle contractions underlying the facial emotional expressions and the amount of facial action units activated constitute the determining factor regarding ease of recognition. That is, the higher the intensity of muscle contraction, the more apparent the facial features that form the emotional facial expressions, which aligns with the ratings of perceived intensity within this study (see also [60]) and facilitates recognition in qhw.v5i4.5120 both accuracy andPLOS ONE | DOI:10.1371/journal.pone.0147112 January 19,17 /Validation of the ADFES-BIVresponse time (see also [53]) and explains the found differences between the intensities within the current research. At emotion onset not all facial action units are activated (e.g. [44, 69]) and the ones that are activated have not reached their maximum yet. That subtler emotional expressions are less well recognised than intense expressions even though we experience them frequently jir.2012.0140 in social PX-478MedChemExpress PX-478 interactions can be explained evolutionary. With facial emotional expressions serving the communicative function of signalling threat (among others) [70], it can be assumed that the level of threat correlates with the intensity of the expression, i.e. the more intense the expression, the more important to recognise the expression. A reason for why subtle emotional facial expressions are harder to recognise than more intense expressions can also be found in the intention of the encoder. In some situations people mask their feelings based on social norms influenced by culture, context, and personality etc. [71] leading to only subtle expressions (intentionally) hard to recognise. In this case, it can actually be beneficial in the interaction to not perceive and recognise the emotion. In this context, it would be interesting to examine if highly empathic people are better than low empathic people at recognising subtle emotional expressions; a question that could be investigated with the ADFES-BIV. Next to the intensity of expression, the found differences in accuracy and response latencies between the intensity levels from the ADFES-BIV could also be explained by the varying amount of display time of emotional content between the intensities in the videos. This was tested in Study 2 with controlled exposition time and results showed the same pattern of accuracy and response latencies for the different intensities as in Study 1. In the ADFES-BIV the accuracy increased by 12 from the low to intermediate category and by 7 for the intermediate to high intensity. Similarly, in Study 2 the accuracy increased by 15 from low to intermediate intensity, and by 8 from intermediate to high intensity. In both studies responses occurred faster to high intensity expressions than low intensity, although in Study 2 the differences between the intensities were smaller from low to intermediate than from intermediate to high, whereas in Study 1 the differences were consistent. This demonstrates that the respo.Expressions (raw: 68 , unbiased: 54 ) to high intensity expressions (raw: 75 , unbiased: 63 ) of the ADFES-BIV is in line with previous research from morphed static stimuli looking at varying intensities where accuracy was linearly associated with physical expression intensity (see [44]) and has been shown for the first time from dynamic stimuli, i.e. video recordings. The lower response times in higher intensities support the notion that responding occurs more rapidly the easier a stimulus is to recognise [28]. The intensity of the muscle contractions underlying the facial emotional expressions and the amount of facial action units activated constitute the determining factor regarding ease of recognition. That is, the higher the intensity of muscle contraction, the more apparent the facial features that form the emotional facial expressions, which aligns with the ratings of perceived intensity within this study (see also [60]) and facilitates recognition in qhw.v5i4.5120 both accuracy andPLOS ONE | DOI:10.1371/journal.pone.0147112 January 19,17 /Validation of the ADFES-BIVresponse time (see also [53]) and explains the found differences between the intensities within the current research. At emotion onset not all facial action units are activated (e.g. [44, 69]) and the ones that are activated have not reached their maximum yet. That subtler emotional expressions are less well recognised than intense expressions even though we experience them frequently jir.2012.0140 in social interactions can be explained evolutionary. With facial emotional expressions serving the communicative function of signalling threat (among others) [70], it can be assumed that the level of threat correlates with the intensity of the expression, i.e. the more intense the expression, the more important to recognise the expression. A reason for why subtle emotional facial expressions are harder to recognise than more intense expressions can also be found in the intention of the encoder. In some situations people mask their feelings based on social norms influenced by culture, context, and personality etc. [71] leading to only subtle expressions (intentionally) hard to recognise. In this case, it can actually be beneficial in the interaction to not perceive and recognise the emotion. In this context, it would be interesting to examine if highly empathic people are better than low empathic people at recognising subtle emotional expressions; a question that could be investigated with the ADFES-BIV. Next to the intensity of expression, the found differences in accuracy and response latencies between the intensity levels from the ADFES-BIV could also be explained by the varying amount of display time of emotional content between the intensities in the videos. This was tested in Study 2 with controlled exposition time and results showed the same pattern of accuracy and response latencies for the different intensities as in Study 1. In the ADFES-BIV the accuracy increased by 12 from the low to intermediate category and by 7 for the intermediate to high intensity. Similarly, in Study 2 the accuracy increased by 15 from low to intermediate intensity, and by 8 from intermediate to high intensity. In both studies responses occurred faster to high intensity expressions than low intensity, although in Study 2 the differences between the intensities were smaller from low to intermediate than from intermediate to high, whereas in Study 1 the differences were consistent. This demonstrates that the respo.
