No / The purpose of this article is to determine the relative importance to adaptive locomotion of peripheral visual cues provided by different parts of the visual field. Twelve subjects completed obstacle crossing trials while wearing goggles that provided four visual conditions: upper visual field occlusion, lower visual field occlusion (LO), circumferential peripheral visual field occlusion (CPO), and full vision. The obstacle was either positioned as a lone structure or within a doorframe. Given that subjects completed the task safely without cues from the lower or peripheral visual field, this suggests that subjects used exteroceptive information provided in a feed-forward manner under these conditions. LO and CPO led to increased foot placement distance from the obstacle and to increased toe clearance over the obstacle with a reduced crossing-walking velocity. The increased variability of dependent measures under LO and CPO suggests that exproprioceptive information from the peripheral visual field is generally used to provide online control of lower limbs. The presence of the doorframe facilitated lead-foot placement under LO by providing exproprioceptive cues in the upper visual field. However, under CPO conditions, the doorframe led to a further reduction in crossing velocity and increase in trail-foot horizontal distance and lead-toe clearance, which may have been because of concerns about hitting the doorframe with the head and/or upper body. Our findings suggest that exteroceptive cues are provided by the central visual field and are used in a feed-forward manner to plan the gait adaptations required to safely negotiate an obstacle, whereas exproprioceptive information is provided by the peripheral visual field and used online to “fine tune” adaptive gait. The loss of the upper and lower peripheral visual fields together had a greater effect on adaptive gait compared with the loss of the lower visual field alone, likely because of the absence of lamellar flow visual cues used to control egomotion.

Body ownership is a complicated and multifaceted percept. Although we subjectively perceive body ownership to be a stable component of our identity, recent work has illustrated that body ownership is a dynamic construct that is constantly updated by the integration of current endogenous and exogenous body-related information. The goal of this study was to explore the relation between these endogenous (interoceptive) and exogenous (exteroceptive) channels of information. We investigated this by using a heartbeat perception (HBP) task to measure interoceptive accuracy, and the Rubber Hand Illusion (RHI) to measure malleability of body ownership. Based on prior findings, we hypothesized that the less accurate you are at counting your heartbeats, the more susceptible you will be to the RHI (i.e. the more malleable your sense of body ownership will be). In addition, we were also interested in exploring the relationship between interoception and emotion recognition ability (ERA). In this experiment, we failed to induce the RHI, and thus could not investigate the relationship between endogenous and exogenous body-related information. However, we successfully demonstrated the reliability of the interoceptive accuracy HBP task, as well as demonstrated that interoceptive accuracy is not related to ERA. / Thesis / Master of Science (MSc)

The main problems concerning birth of running injuries is their unclear ethiopathogenesis and high frequency. Injuries are often lined with forces affected on tread-down which have to be defused by running shoes. There are also opinions that currently used footwear can cause injuries on the contrary. This work explores impact of particular types of running shoes for influencing of stability. Methods: There are compared two groups of runners: minimalists and classic runners. Their stability is examined with help of posturography in three versions: barefoot, classic and minimalistic footwear. Thereafter there is analyzed relation among stability, used footwear, training usage and frequency of injuries. Results: Minimalists and classic runners have the same stability while they are barefoot. Usage of footwear does not cause significant deterioration of stability in any of groups. Nevertheless most of runners subjectively evaluate the variant of testing barefoot as the simplest. There is more frequent occurence of flat foot among classic runners in comparison with minimalists. Flat foot increases risk of formation injuries, on the contrary, regular compensation motion activity decreases this risk.

Visual cues have previously been classified as visual exproprioceptive, when defining the relative position of the body within the environment and are continuously updated while moving (online), and visual exteroceptive when describing static features of the environment which are typically elaborated offline (feedforward). However peripheral visual cues involved in the control of movement have not previously been clearly defined using this classification. Hence the role played by peripheral visual cues in the planning and/or online control of movement remains unclear. The aim of this thesis was to provide a systematic understanding of the importance of peripheral visual cues in several types of movement, namely overground locomotion, adaptive gait, postural stability and reaching and grasping. 3D motion capture techniques were used to collect limb and whole body kinematics during such movements. Visual peripheral cues were manipulated by visual field occlusion conditions or by the employment of point-lights in a dark room. Results showed that the visual cues provided by different parts of the peripheral visual field are mainly used for online fine tuning of limb trajectory towards a target (either a floor-based obstacle or an object to grasp). The absence of peripheral visual cues while moving disrupted the spatio-temporal dynamic relationship between subject and target and resulted in increased margins of safety between body and target and increased time and variability of several dependent measures. These findings argue in favour of the classification of peripheral visual cues as visual exproprioceptive.

Visual cues have previously been classified as visual exproprioceptive, when defining the relative position of the body within the environment and are continuously updated while moving (online), and visual exteroceptive when describing static features of the environment which are typically elaborated offline (feedforward). However peripheral visual cues involved in the control of movement have not previously been clearly defined using this classification. Hence the role played by peripheral visual cues in the planning and/or online control of movement remains unclear. The aim of this thesis was to provide a systematic understanding of the importance of peripheral visual cues in several types of movement, namely overground locomotion, adaptive gait, postural stability and reaching and grasping. 3D motion capture techniques were used to collect limb and whole body kinematics during such movements. Visual peripheral cues were manipulated by visual field occlusion conditions or by the employment of point-lights in a dark room. Results showed that the visual cues provided by different parts of the peripheral visual field are mainly used for online fine tuning of limb trajectory towards a target (either a floor-based obstacle or an object to grasp). The absence of peripheral visual cues while moving disrupted the spatio-temporal dynamic relationship between subject and target and resulted in increased margins of safety between body and target and increased time and variability of several dependent measures. These findings argue in favour of the classification of peripheral visual cues as visual exproprioceptive.