Non-visually-guided distance perception depends on matching torso fluctuations between training and test

Abstract

Blindwalking to replicate an instructed distance requires various sensory signals. Recent evidence in movement science across many organisms suggests that multifractal organization of connective tissue supports the use of these signals. Multifractal structure is a multiplicity of power laws defining distribution of proportion across many time scales that helps predict judgments of the objects' length. Present work tests whether the multifractal structure in postural accelerometry during blindwalking predicts blindwalking distance replications. Ten undergraduate student participants each completed 20 trials of distance-perception each comprising two laps. On each Lap 1, experimenters led participants to walk on any of five prescribed distances, randomly assigning half to walk Lap 1 with eyes open and another half to walked Lap 1 with eyes closed. On Lap 2, all participants walked with eyes closed to replicate instructed distances from Lap 1. We collected postural accelerometry from the torso during each lap. Regression modeling showed that multifractality of postural accelerometry on both Lap 1 and Lap 2 contributed significantly to Lap-2 blindwalking responses. According to this model, more accurate Lap-2 replications of Lap-1 distance came from eyes-closed participants whose posture had comparable multifractality on both laps. Multifractality provides insights into the sequence of exploratory behaviors for blindwalking responses to distance perception.Keywords Perception and action . Haptics . Kinesthesis Distance perception draws on multiple physiological systems. Optical variables inform sighted distance judgments (e.g., Wu, He, & Ooi, 2007), and participants with eyes closed can blindly walk a distance commensurate with distance to that target (Thomson, 1983;Elliott, 1986). Blindwalking participants use haptic information from footfalls and postural corrections to feel their way on "how long" it is to the target (Loomis, Da Silva, Fujita, & Fukusima, 1992;Loomis et al., 1993). Vestibular signals provide self-motion cues (e.g., Etienne & Jeffery, 2004;McNaughton, Battaglia, Jensen, Moser, & Moser, 2006). Blindwalking participants must integrate their visual trace with an efference copy encoding muscular effort together with various vestibular, tactile, and proprioceptive signals (Ivanenko, Grasso, Israel, & Berthoz, 1997).Signal transmissions from footfall to central executive rely on the nesting of connective tissues across various scales weaving muscle, tendon, bone, and nervous tissue together. Of course, the signals travel through neural tracts in humans, but postural adaptations occur faster than neural transmission allows in multicellular organisms much smaller than humans posing shorter neural distances to traverse (e.g., Endlein & Federle, 2013) but also in humans, supporting quiet standing (Marsden, Merton, & Morton, 1983), speech (Kelso, Tuller, Vatikiotis-Bateson, & Fowler, 1984), and hopping (Moritz & Farley, 2004). The connective tissues constitute a hierarchically organized network of s...

Gesturing more diminishes recall of abstract words when gesture is allowed and concrete words when it is taboo

“…This perhaps-strange point rests as straightforwardly on neural evidence that cortical areas active during speech production share overlap with cortical areas active during passive listening (Wilson, Saygin, Sereno, & Iacoboni, 2004) as on lesser known evidence that hierarchically organized connective tissue supporting movement binds auditory and articulatory neurons together to do what neurons alone cannot, providing pre-stressed platforms on which neurons can function as needed (Ingber, 2006;Kelso, Tuller, Vatikiotis-Bateson, & Fowler, 1984). Memory may depend on this bodywide connective tissue assuming a similar hierarchical organization during test as during study (Teng, Eddy, & Kelty-Stephen, 2016), and future work might pursue a comparable analysis of hierarchical structure in gestures during and after our Taboo game.…”

Multifractal roots of suprapostural dexterity

“…Visually fixating brings a prestressed quiet stance into one with informational coupling with the visual stimulus. Past work has repeatedly implicated fractal fluctuations in the head and upper torso for using visual information to organize action [28,29,[65][66][67][68]. Visual inspection of IRF plots indicated rare instances of effects from or responses from CoM fractality on or to SD (1 trial in the 50-, 135-, and 305-cm conditions), but the regression modeling indicated no stable relationship.…”

Multifractality in postural sway supports quiet eye training in aiming tasks: A study of golf putting

“…Multifractality, W MF , in postural sway is a robust predictor of perceptual responses in both visual and haptic media (Doyon et al, 2019; Hajnal et al, 2018; Teng et al, 2016). Multifractal nonlinearity, t MF , in postural sway predicts perceptual responses as well, not just in the case of nonvisual judgments of length and heaviness of manually-wielded objects (Mangalam & Kelty-Stephen, 2020) but also in visuomotor tasks (Bell et al, 2019; Booth et al, 2018) and in response to perturbations, such as those due to prismatic goggles in a visual aiming task (Carver et al, 2017).…”