Distinct temporal features of genuine and deliberate facial expressions of surprise

Abstract

The physical properties of genuine and deliberate facial expressions remain elusive. This study focuses on observable dynamic differences between genuine and deliberate expressions of surprise based on the temporal structure of facial parts during emotional expression. Facial expressions of surprise were elicited using multiple methods and video recorded: senders were filmed as they experienced genuine surprise in response to a jack-in-the-box (Genuine), other senders were asked to produce deliberate surprise with no preparation (Improvised), by mimicking the expression of another (External), or by reproducing the surprised face after having first experienced genuine surprise (Rehearsed). A total of 127 videos were analyzed, and moment-to-moment movements of eyelids and eyebrows were annotated with deep learning-based tracking software. Results showed that all surprise displays were mainly composed of raising eyebrows and eyelids movements. Genuine displays included horizontal movement in the left part of the face, but also showed the weakest movement coupling of all conditions. External displays had faster eyebrow and eyelid movement, while Improvised displays showed the strongest coupling of movements. The findings demonstrate the importance of dynamic information in the encoding of genuine and deliberate expressions of surprise and the importance of the production method employed in research.

The spatio-temporal features of perceived-as-genuine and deliberate expressions

“…To reduce the dimensionality and extract the low-dimensional features, a nonnegative matrix factorization was applied to the time-series data of the AUs [44][45][46]. This approach helps obtain interpretable features in a low-dimensional space [44].…”

Spontaneous Facial Expressions and Micro-expressions Coding: From Brain to Face

“…When subjects experienced surprise, the facial movements were described as frowning, eye-widening, and eyebrow raising (Reisenzein et al, 2006 ). Also, in exploring the distinction in dynamics between genuine and deliberate expressions of surprise, it was found that all expressions of surprise consisted mainly of raised eyebrows and eyelid movements (Namba et al, 2021 ). The facial muscles involved in these movements were: corrugator supercilii, orbicularis oculi , and frontalis .…”

Motion Increases Recognition of Naturalistic Postures but not Facial Expressions

“…Deliberately posed expressions also contain different patterns of motion than expressions that correspond with genuinely felt emotion (Namba et al, 2017(Namba et al, , 2021. Examining specific physical components of various emotion expressions has demonstrated differences in which expression components are present in genuine vs. posed expressions, but also differences in the temporal patterns of movement (Namba et al, 2017(Namba et al, , 2021.…”

“…Deliberately posed expressions also contain different patterns of motion than expressions that correspond with genuinely felt emotion (Namba et al, 2017(Namba et al, , 2021. Examining specific physical components of various emotion expressions has demonstrated differences in which expression components are present in genuine vs. posed expressions, but also differences in the temporal patterns of movement (Namba et al, 2017(Namba et al, , 2021. These differences may also explain why presenting expressions dynamically rather than statically improves participants' ability to detect whether expressions were genuine or posed (Namba et al, 2018;Zloteanu et al, 2018).…”