Biology subjects

Kilner, J. M.

Publications and source records attributed to Kilner, J. M..

3 recordsLinked to original sources

bioRxiv2026

Actors' Facial Movement Magnitude and Cardiac Dynamics Predict Observers' Emotion Believability Ratings

In non-verbal communication, observers infer emotions from visible facial movements, yet emotional experiences are described in internal bodily terms (e.g., "my heart skipped a beat")1-3. This contrast highlights a tension between external sensory cues and internal signals. In this context, we examined an overlooked gap in affective science: what makes an emotional portrayal believable, and do believability judgments reflect only what observers can see or also the portraying persons internal cardiac dynamics? To test this, we created 311 scenario-driven acting clips designed to avoid prototypical posed displays4-6. For each clip, we quantified facial movement magnitude from the video, recorded ECG during preparation and enactment, and collected actors self-reports. Online participants (N = 371) viewed these clips and provided emotion recognition responses and continuous ratings of believability, valence, or arousal. The results show that believability decreased as movement magnitude increased, with a non-linear relationship indicating a stronger penalty as motion increased. Valence further shaped this pattern, with increasing movement reducing believability more strongly for portrayals with negative valence. This effect persisted after accounting for intended emotion, perceived arousal, and emotion recognizability. Cardiac dynamics varied during performance, and actors higher heart rate variability was associated with higher believability for positively valenced portrayals. Together, these findings show that believability is driven by visible movement cues interpreted in relation to valence, with actors cardiac dynamics showing selective alignment with believability. These results identify core components of believable emotional expressions and provide a basis for studying such judgments in everyday social interaction. HighlightsO_LILarger facial movements were associated with lower believability, non-linearly C_LIO_LINegative valence portrayals were penalized more strongly for large movements C_LIO_LIEmotion recognizability did not explain believability, even after adjustment C_LIO_LIActor heart-rate variability was associated with higher believability in positive portrayals C_LI

physiology↗

bioRxiv2022

Active tactile discrimination is coupled with and modulated by the cardiac cycle

Perception and cognition are modulated by the phase of the cardiac signal in which the stimuli are presented. This has been shown by locking the presentation of stimuli to distinct cardiac phases. However, in everyday life sensory information is not presented in this phase-locked and passive manner, instead we actively sample the world. Whether active sensing is coupled and modulated with the cardiac cycle remains largely unknown. Here we recorded the ECGs of human participants while they actively performed a tactile grating orientation task. Here we show that the duration of subjects touch varied as a function of the cardiac phase in which they initiated it. Touches initiated in the systolic phase of the cardiac cycle were held for longer periods of time than touches initiated in the diastolic phase. This effect was driven by the elongation of their holds to sample the most difficult gratings. Conversely, while touches in the control condition were coupled to the cardiac cycle, their length was not modulated as a function of when in the cycle these were initiated. In line with interoceptive inference accounts, these results are consistent with the hypotheses that we actively adjust our sensory sampling so that we spend more time in the diastole period of the cardiac cycle in which perceptual sensory sensitivity is greatest.

neuroscience↗

bioRxiv2019

Relationship between cardiac cycle and the timing of actions during action execution and observation

Previous research suggests that there may be a relationship between the timing of motor events and phases of the cardiac cycle. However, this relationship has thus far only been researched using simple isolated movements such as key-presses in reaction-time tasks and only in a single subject acting alone. Other research has shown both movement and cardiac coordination among interacting individuals. Here, we investigated how the cardiac cycle relates to ongoing self-paced movements in both action execution and observation using a novel dyadic paradigm. We recorded electrocardiography (ECG) in 26 healthy adult subjects who formed 19 dyads (7 comprised of two subjects and 12 subjects paired with an experimenter). Each dyad contained an action executioner and observer as they performed a self-paced sequence of movements. We demonstrated that heartbeats are timed to movements during both action execution and observation. Specifically, movements were less likely to culminate synchronously with the heartbeat, around the time of the R-peak of the ECG. The same pattern was observed for action observation, with the observers heartbeats occurring off-phase with movement culmination. These findings demonstrate that there is coordination between an action executioners cardiac cycle and the timing of their movements, and that the same relationship is mirrored in an observer. This suggests that previous findings of interpersonal coordination may be caused by the mirroring of a phasic relationship between movement and the heart.

neuroscience↗