Infants show a dramatic shift in postural and emotional responsiveness to peripheral lamellar optic flow (PLOF) following crawling onset. The present study used a novel virtual moving room to assess postural compensation of the shoulders backward and upward and heart rate acceleration to PLOF specifying a sudden horizontal forward translation and a sudden descent down a steep slope in an infinitely long virtual tunnel. No motion control conditions were also included. Participants were 53 8.5-month-old infants: 25 prelocomotors and 28 hands-and-knees crawlers. The primary findings were that crawling infants showed directionally appropriate postural compensation in the two tunnel motion conditions, whereas prelocomotor infants were minimally responsive in both conditions. Similarly, prelocomotor infants showed nonsignificant changes in heart rate acceleration in the tunnel motion conditions, whereas crawling infants showed significantly higher heart rate acceleration in the descent condition than in the descent control condition, and in the descent condition than in the horizontal translation condition. These findings highlight the important role played by locomotor experience in the development of the visual control of posture and in emotional reactions to a sudden optically specified drop. The virtual moving room is a promising paradigm for exploring the development of perception–action coupling.
Moeko Ueno, Ichiro Uchiyama, Joseph J. Campos, David I. Anderson, Minxuan He and Audun Dahl
Ana M. F. Barela, José A. Barela, Natália M. Rinaldi and Diana R. de Toledo
This study examined the influence of both optic flow characteristics and intention on postural control responses. Two groups of 10 adults each were exposed to the room’s movement either at 0.6 cm/s (low velocity group) or 1.0 cm/s (high velocity group). All the participants stood in the upright stance inside of a moving room and were informed about the room movement only after the fourth trial as they were asked to resist to its influence. Results revealed that participants from both groups were influenced by the imposed visual stimulus in the first trials, but the coupling strength was weaker for the high velocity group. The request to resist the visual influences decreased visual influences on body sway, but only for the low velocity group. These results indicate that intention might play a role in stimulus influences on body sway but it is stimulus dependent.
Olivier Oullier, Benoît G. Bardy, Thomas A. Stoffregen and Reinoud J. Bootsma
Surfaces shorter in extent than the feet elicit multi-joint coordination that differs from what is elicited by stance on extensive surfaces. This well-known effect arises from the mechanics of the actor-environment interaction. Multi-joint control of stance is also known to be influenced by non-mechanical aspects of a situation, including participants' task or intention. Intentional constraints do not originate in mechanics, and for this reason one might suppose that constraints imposed by mechanics would dominate constraints imposed by intentions, when the two were in conflict. We evaluated this hypothesis by varying participants' supra-postural task during stance on a short surface. While standing on a 10-cm wide beam, participants were exposed to optic flow generated by fore-aft oscillations of a moving room. Participants faced a target attached to the front wall of the moving room and were asked either to look at the target (with no instruction to move) or intentionally to track it with their head (i.e., to keep the target-head distance constant). Within trials, we varied the frequency of room (and target) motion, from 0.15 to 0.75 Hz, in steps of 0.05 Hz. In both conditions, ankle and hip rotations exhibited antiphase coordination, but behavior was not identical across conditions. Coupling between motion of the room and the head was stronger for the tracking task than for the looking task, and the stability of ankle-hip coordination was greater during tracking than during looking. These results indicate that the influence of support surface mechanics did not eliminate the influence of the supra-postural task. Environment-based and task-based constraints interacted in determining the coordination of hips and ankles during stance.
Thomas A. Stoffregen, Philip Hove, Jennifer Schmit and Benoît G. Bardy
We demonstrated that postural responses to imposed optic flow are to some extent voluntary. In a moving room, participants either stood normally or were instructed to resist any influence of visible motion on their stance. When participants attempted to resist, coupling of body sway with motion of the room was significantly greater than when the eyes were closed, but was significantly reduced relative to coupling in the normal stance condition. The results indicate that the use of imposed optic flow for postural control is not entirely automatic or involuntary. This conclusion motivates a search for non-perceptual factors that may influence the degree to which body sway is coupled to imposed optic flow.
Paula F. Polastri and and José A. Barela
This study examined the effects of experience and practice on the coupling between visual information and trunk sway in infants with Down syndrome (DS). Five experienced and five novice sitters were exposed to a moving room, which was oscillated at 0.2 and 0.5 Hz. Infants remained in a sitting position and data were collected on the first, fourth, and seventh days. On the first day, experienced sitters were more influenced by room oscillation than were novices. On the following days, however, the influence of room oscillation decreased for experienced but increased for novice sitters. These results suggest that the relationship between sensory information and motor action in infants with DS can be changed with experience and practice.
-Month-Old Infants Understand the Relationship Between Object Weight and Compression in Support Events Michaela B. Upshaw * Jessica Sommerville * 4 2018 6 s1 S44 S62 10.1123/jmld.2016-0068 Crawling Experience Relates to Postural and Emotional Reactions to Optic Flow in a Virtual Moving Room Moeko Ueno * Ichiro
Anat V. Lubetzky, Daphna Harel, Helene Darmanin and Ken Perlin
laboratory-based screen ( Lubetzky-Vilnai et al., 2015 ), and “moving room” ( Polastri & Barela, 2013 ) systems to create a reliable test. If our hypothesis is supported, the sensory weighting and reweighting paradigm can be further developed into a clinical assessment of visual dependence for postural
Pedro Paulo Deprá, Avelino Amado and Richard E.A. van Emmerik
postural task (unipedal support). Our current finding of the association between reduced postural TtC and better visual task performance is also consistent with recent research from Li et al. ( 2018 ). Li et al. examined the postural TtC before and during exposure to visual motion stimuli in a moving room
Gustavo Sandri Heidner, Patrick M. Rider, J.C. Mizelle, Caitlin M. O’Connell, Nicholas P. Murray and Zachary J. Domire
to the environment he was in before, lacking reference to the floor, the walls, and objects around him, as all this information now needs to be integrated along with the moving room, for example, a room with black and white checkered walls and ceilings. Ellis 18 reported that air traffic controllers
Jill Whitall, Nadja Schott, Leah E. Robinson, Farid Bardid and Jane E. Clark
. The response to the perturbation allowed the researcher to decide how developed the infant’s sensorimotor system was at particular time-points. For example, the development of postural control was investigated through moving room experiments ( Bertenthal, Rose, & Bai, 1997 ) and through platform