Slow motion in films and video clips: Music influences perceived duration and emotion, autonomic physiological activation and pupillary responses

The role of valence, arousal, stimulus type, and temporal paradigm in the effect of emotion on time perception: A meta-analysis

Anecdotal experiences show that the human perception of time is subjective, and changes with one's emotional state. Over the past 25 years, increasing empirical evidence has demonstrated that emotions distort time perception and usually result in overestimation. Yet, some inconsistencies deserve clarification. Specifically, it remains controversial how valence (positive/negative), arousal (high/low), stimulus type (scenic picture/facial expression/word/sound), and temporal paradigm (reproduction/estimation/discrimination) modulate the effect of emotion on time perception. Thus, the current study aimed to conduct a meta-analysis to quantify evidence for these moderators. After searching the Web of Science, SpiScholar, and Google Scholar, 95 effect sizes from 31 empirical studies were calculated using Hedges'g. The included studies involved 3,776 participants. The results a highlighted significant moderating effect of valence, arousal, stimulus type, and temporal paradigm. Specifically, negative valence tends to result in overestimation relative to positive valence; the increasing arousal leads to increasing temporal dilating; scenic picture, facial picture, and sound are more effective in inducing distortions than word; the overestimation can be better observed by discrimination and estimation paradigms relative to reproduction paradigms, and estimation paradigm is likely to be the most effective. These results suggest that the effect of emotion on time perception is influenced by valence, arousal, stimulus type, and temporal paradigm. These mitigating factors should be considered by scientists when studying time perception.

Inconclusive evidence that breathing shapes pupil dynamics in humans: a systematic review

More than 50 years ago, it was proposed that breathing shapes pupil dynamics. This widespread idea is also the general understanding currently. However, there has been no attempt at synthesizing the progress on this topic since. We therefore conducted a systematic review of the literature on how breathing affects pupil dynamics in humans. We assessed the effect of breathing phase, depth, rate, and route (nose/mouth). We followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, and conducted a systematic search of the scientific literature databases MEDLINE, Web of Science, and PsycInfo in November 2021. Thirty-one studies were included in the final analyses, and their quality was assessed with QualSyst. The study findings were summarized in a descriptive manner, and the strength of the evidence for each parameter was estimated following the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach. The effect of breathing phase on pupil dynamics was rated as "low" (6 studies). The effect of breathing depth and breathing rate (6 and 20 studies respectively) were rated as "very low". Breathing route was not investigated by any of the included studies. Overall, we show that there is, at best, inconclusive evidence for an effect of breathing on pupil dynamics in humans. Finally, we suggest some possible confounders to be considered, and outstanding questions that need to be addressed, to answer this fundamental question. Trial registration: This systematic review has been registered in the international prospective register of systematic reviews (PROSPERO) under the registration number: CRD42022285044.

Time perception in film is modulated by sensory modality and arousal

Considerable research has shown that the perception of time can be distorted subjectively, but little empirical work has examined what factors affect time perception in film, a naturalistic multimodal stimulus. Here, we explore the effect of sensory modality, arousal, and valence on how participants estimate durations in film. Using behavioral ratings combined with pupillometry in a within-participants design, we analyzed responses to and duration estimates of film clips in three experimental conditions: audiovisual (containing music and sound effects), visual (without music and sound effects), and auditory (music and sound effects without a visual scene). Participants viewed clips from little-known nature documentaries, fiction, animation, and experimental films. They were asked to judge clip duration and to report subjective arousal and valence, as their pupil sizes were recorded. Data were analyzed using linear mixed-effects models. Results reveal duration estimates varied between experimental conditions. Clip durations were judged to be shorter than actual durations in all three conditions, with visual-only clips perceived as longer (i.e., less distorted in time) than auditory-only and audiovisual clips. High levels of Composite Arousal (an average of self-reported arousal and pupil size changes) were correlated with longer (more accurate) estimates of duration, particularly in the audiovisual modality. This effect may reflect stimulus complexity or greater cognitive engagement. Increased ratings of valence were correlated with longer estimates of duration. The use of naturalistic, complex stimuli such as film can enhance our understanding of the psychology of time perception.

Tapping to hip-hop: Effects of cognitive load, arousal, and musical meter on time experiences

Experiences of time vary intra- and interindividually, depending on factors such as attentional resource allocation and arousal. Music as a temporal art that is structured by multiple temporal layers is ideal for investigating human time experiences. The current study used examples of hip-hop music that varied in arousal but were constant in tempo. Participants judged the passage of time to be quicker when cognitive load was high in a dual-task condition, and perceived duration to be shorter when performing a concurrent motor task (tapping along with the music). Perceived musical arousal did not affect subjective time. Attending to a higher metrical level by tapping with half notes resulted in shorter duration estimates and a quicker passage of time, compared to tapping with eighth notes of the same music. Results were not influenced by spontaneous motor tempo, musical expertise, preference or familiarity with the music. Taken together, these findings indicate consistent effects of cognitive load and attention to meter on time experiences.

Time perception in human movement: Effects of speed and agency on duration estimation

While the effects of synthesised visual stimuli on time perception processes are well documented, very little research on time estimation in human movement stimuli exists. This study investigated the effects of movement speed and agency on duration estimation of human motion. Participants were recorded using optical motion capture while they performed dance-like movements at three different speeds. They later returned for a perceptual experiment in which they watched point-light displays of themselves and one other participant. Participants were asked to identify themselves, to estimate the duration of the recordings, and to rate expressivity and quality of the movements. Results indicate that speed of movement affected duration estimations such that faster speeds were rated longer, in accordance with previous findings in non-biological motion. The biasing effects of speed were stronger for watching others' movements than for watching one's own point-light movements. Duration estimations were longer after acting out the movement compared with watching it, and speed differentially affected ratings of expressivity and quality. Findings suggest that aspects of temporal processing of visual stimuli may be modulated by inner motor representations of previously performed movements, and by physically carrying out an action compared with just watching it. Results also support the inner clock and change theories of time perception for the processing of human motion stimuli, which can inform the temporal mechanisms of the hypothesised separate processor for human movement information.

Sensorimotor synchronisation with higher metrical levels in music shortens perceived time

The aim of the present study was to investigate if the perception of time is affected by actively attending to different metrical levels in musical rhythmic patterns. In an experiment with a repeated-measures design, musicians and non-musicians were presented with musical rhythmic patterns played at three different tempi. They synchronised with multiple metrical levels (half notes, quarter notes, eighth notes) of these patterns using a finger-tapping paradigm and listened without tapping. After each trial, stimulus duration was judged using a verbal estimation paradigm. Results show that the metrical level participants synchronised with influenced perceived time: actively attending to a higher metrical level (half notes, longer inter-tap intervals) led to the shortest time estimations, hence time was experienced as passing more quickly. Listening without tapping led to the longest time estimations. The faster the tempo of the patterns, the longer the time estimation. While there were no differences between musicians and non-musicians, those participants who tapped more consistently and accurately (as analysed by circular statistics) estimated durations to be shorter. Thus, attending to different metrical levels in music, by deliberately directing attention and motor activity, affects time perception.

Cortical modulation of pupillary function: systematic review

BACKGROUND

The pupillary light reflex is the main mechanism that regulates the pupillary diameter; it is controlled by the autonomic system and mediated by subcortical pathways. In addition, cognitive and emotional processes influence pupillary function due to input from cortical innervation, but the exact circuits remain poorly understood. We performed a systematic review to evaluate the mechanisms behind pupillary changes associated with cognitive efforts and processing of emotions and to investigate the cerebral areas involved in cortical modulation of the pupillary light reflex.

METHODOLOGY

We searched multiple databases until November 2018 for studies on cortical modulation of pupillary function in humans and non-human primates. Of 8,809 papers screened, 258 studies were included.

RESULTS

Most investigators focused on pupillary dilatation and/or constriction as an index of cognitive and emotional processing, evaluating how changes in pupillary diameter reflect levels of attention and arousal. Only few tried to correlate specific cerebral areas to pupillary changes, using either cortical activation models (employing micro-stimulation of cortical structures in non-human primates) or cortical lesion models (e.g., investigating patients with stroke and damage to salient cortical and/or subcortical areas). Results suggest the involvement of several cortical regions, including the insular cortex (Brodmann areas 13 and 16), the frontal eye field (Brodmann area 8) and the prefrontal cortex (Brodmann areas 11 and 25), and of subcortical structures such as the locus coeruleus and the superior colliculus.

CONCLUSIONS

Pupillary dilatation occurs with many kinds of mental or emotional processes, following sympathetic activation or parasympathetic inhibition. Conversely, pupillary constriction may occur with anticipation of a bright stimulus (even in its absence) and relies on a parasympathetic activation. All these reactions are controlled by subcortical and cortical structures that are directly or indirectly connected to the brainstem pupillary innervation system.

The impact of music and stretched time on pupillary responses and eye movements in slow-motion film scenes

This study investigated the effects of music and playback speed on arousal and visual perception in slow-motion scenes taken from commercial films. Slow-motion scenes are a ubiquitous film technique and highly popular. Yet the psychological effects of mediated time-stretching compared to real-time motion have not been empirically investigated. We hypothesised that music affects arousal and attentional processes. Furthermore, we as-sumed that playback speed influences viewers’ visual perception, resulting in a higher number of eye movements and larger gaze dispersion. Thirty-nine participants watched three film excerpts in a repeated-measures design in conditions with or without music and in slow motion vs. adapted real-time motion (both visual-only). Results show that music in slow-motion film scenes leads to higher arousal compared to no music as indicated by larger pupil diameters in the former. There was no systematic effect of music on visual perception in terms of eye movements. Playback speed influenced visual perception in eye movement parameters such that slow motion resulted in more and shorter fixations as well as more saccades compared to adapted real-time motion. Furthermore, in slow motion there was a higher gaze dispersion and a smaller centre bias, indicating that individuals attended to more detail in slow motion scenes.