Fractal Structure of Event Segmentation: Lessons From Reel and Real Events

Being in a crowd bonds people via physiological synchrony

Collective events can generate intense emotions, shape group identities, and forge strong bonds. Do these effects extend to remote participation, and what are the psychological mechanisms underpinning their social power? We monitored psycho-physiological activity among groups of basketball fans who either attended games in-person (in a stadium) or watched games live on television in small groups. In-person attendance was associated with greater synchronicity in autonomic nervous system activation at the group level, which resulted in more transformative experiences and contributed to stronger identity fusion. Our findings suggest that the social effects of sports depend substantially on the inter-personal dynamics unfolding among fans, rather than being prompted simply by watching the game itself. Given the increasing prevalence of virtual experiences, this has potentially wide-reaching implications for many domains of collective human interaction.

Brain meta-state transitions demarcate thoughts across task contexts exposing the mental noise of trait neuroticism

Researchers have observed large-scale neural meta-state transitions that align to narrative events during movie-viewing. However, group or training-derived priors have been needed to detect them. Here, we introduce methods to sample transitions without any priors. Transitions detected by our methods predict narrative events, are similar across task and rest, and are correlated with activation of regions associated with spontaneous thought. Based on the centrality of semantics to thought, we argue these transitions serve as general, implicit neurobiological markers of new thoughts, and that their frequency, which is stable across contexts, approximates participants' mentation rate. By enabling observation of idiosyncratic transitions, our approach supports many applications, including phenomenological access to the black box of resting cognition. To illustrate the utility of this access, we regress resting fMRI transition rate and movie-viewing transition conformity against trait neuroticism, thereby providing a first neural confirmation of mental noise theory.

Perceptual Underpinnings for “Good” Editing: A Fractal Analysis

Filmmakers’ efforts not only advance film as an art form, they also provide insights about basic perception. This research was designed to uncover commonalities between the aesthetic appreciation of viewers of films and the perceptual capacities of observers of environmental events. We assessed whether the temporal structure of events in the environment is reflected in the temporal structure of events in film. Participants in Study 1 segmented neutral environmental events to establish a benchmark temporal structure. Study 2 compared the temporal structure of editing in amateur and professionally made films. Results from these two studies suggest a particular fractal structure common to environmental event perception and the editing structure of professional films. This hypothesis was then tested in an experiment that reedited one film so as to produce four different versions, each with a different fractal structure. These versions were evaluated by audiences in terms of aesthetics (e.g., general likability, comprehension, technical aspects of craft). The results suggest that the fractal structure typical of environmental event perception is preferred, even when it is not the original, artistically intended version. It is argued that narrative films succeed, at least in part, because their temporal structure reflects the temporal structure of environmental event perception.

When Coordinating Finger Tapping to a Variable Beat the Variability Scaling Structure of the Movement and the Cortical BOLD Signal are Both Entrained to the Auditory Stimuli

Rhythmic actions are characterizable as a repeating invariant pattern of movement together with variability taking the form of cycle-to-cycle fluctuations. Variability in behavioral measures is atypically random, and often exhibits serial temporal dependencies and statistical self-similarity in the scaling of variability magnitudes across timescales. Self-similar (i.e. fractal) variability scaling is evident in measures of both brain and behavior. Variability scaling structure can be quantified via the scaling exponent (α) from detrended fluctuation analysis (DFA). Here we study the task of coordinating thumb-finger tapping to the beats of constructed auditory stimuli. We test the hypothesis that variability scaling evident in tap-to-tap intervals as well as in the fluctuations of cortical hemodynamics will become entrained to (i.e. drawn toward) manipulated changes in the variability scaling of a stimulus's beat-to-beat intervals. Consistent with this hypothesis, manipulated changes of the exponent α of the experimental stimuli produced corresponding changes in the exponent α of both tap-to-tap intervals and cortical hemodynamics. The changes in hemodynamics were observed in both motor and sensorimotor cortical areas in the contralateral hemisphere. These results were observed only for the longer timescales of the detrended fluctuation analysis used to measure the exponent α. These findings suggest that complex auditory stimuli engage both brain and behavior at the level of variability scaling structures.