Transfer of attunement in length perception by dynamic touch

A systematic review of perception of affordances for the person-plus-object system

Human behavior often involves the use of an object held by or attached to the body, which modifies the individual's action capabilities. Moreover, most everyday behaviors consist of sets of behaviors that are nested over multiple spatial and temporal scales, which require perceiving and acting on nested affordances for the person-plus-object system. This systematic review investigates how individuals attune to information about affordances involving the person-plus-object system and how they (re)calibrate their actions to relevant information. We analyzed 71 articles-34 on attunement and 37 on (re)calibration with healthy participants-that experimentally investigated the processes involved in the perception of affordances for the person-plus-object system (including attunement, calibration, and recalibration). With respect to attunement, objects attached to the body create a multiplicity of affordances for the person-plus-object system, and individuals learned (1) to detect information about affordances of (and for) the person-plus-object system in a task and (2) to choose whether, when, and how to exploit those affordances to perform that task. Concerning (re)calibration, individuals were able (1) to quickly scale their actions in relation to the (changed) action capabilities of the person-plus-object system and (2) to perceive multiple functionally equivalent ways to exploit the affordances of that system, and these abilities improved with practice. Perceiving affordances for the person-plus-object system involves learning to detect the information about such affordances (attunement) and the scaling of behaviors to such information (calibration). These processes imply a general ability to incorporate an object attached to the body into an integrated person-plus-object system.

Metastable attunement and real-life skilled behavior

In everyday situations, and particularly in some sport and working contexts, humans face an inherently unpredictable and uncertain environment. All sorts of unpredictable and unexpected things happen but typically people are able to skillfully adapt. In this paper, we address two key questions in cognitive science. First, how is an agent able to bring its previously learned skill to bear on a novel situation? Second, how can an agent be both sensitive to the particularity of a given situation, while remaining flexibly poised for many other possibilities for action? We will argue that both the sensitivity to novel situations and the sensitivity to a multiplicity of action possibilities are enabled by the property of skilled agency that we will call metastable attunement. We characterize a skilled agent's flexible interactions with a dynamically changing environment in terms of metastable dynamics in agent-environment systems. What we find in metastability is the realization of two competing tendencies: the tendency of the agent to express their intrinsic dynamics and the tendency to search for new possibilities. Metastably attuned agents are ready to engage with a multiplicity of affordances, allowing for a balance between stability and flexibility. On the one hand, agents are able to exploit affordances they are attuned to, while at the same time being ready to flexibly explore for other affordances. Metastable attunement allows agents to smoothly transition between these possible configurations so as to adapt their behaviour to what the particular situation requires. We go on to describe the role metastability plays in learning of new skills, and in skilful behaviour more generally. Finally, drawing upon work in art, architecture and sports science, we develop a number of perspectives on how to investigate metastable attunement in real life situations.

Learning and transfer of perceptual-motor skill: Relationship with gaze and behavioral exploration

Visual and haptic exploration were shown to be central modes of exploration in the development of locomotion. However, it is unclear how learning affects these modes of exploration in locomotor task such as climbing. The first aim of this study was to investigate the modifications of learners' exploratory activity during the acquisition of a perceptual-motor skill. The second aim was to determine to what extent the acquired perceptual-motor skill and the learners' exploratory activity were transferred to environments presenting novel properties. Seven participants attended 10 learning sessions on wall climbing. The effects of practice were assessed during pretest, posttest, and retention tests, each composed of four climbing routes: the route climbed during the learning sessions and three transfer routes. The transfer routes were designed by manipulating either the distance between handholds, the orientation of the handholds or the handholds shape. The results showed that the number of exploratory hand movements and fixations decreased with practice on the learning route. A visual entropy measure suggested that the gaze path in this route became more goal-directed on posttest, but some search was necessary on the retention test. The number of exploratory movements also decreased on the three transfer routes following practice, whereas the number of fixations was higher than on the learning route, suggesting that, with learning, participants relied more on exploration from a distance to adapt to the new properties of the transfer routes. Analyses of the individual performances and behaviors showed differences in the development of skilled exploratory activity.

Is Perception of Stand-on-able-ness Equivalent Across Degrees of Dynamic Touch?

From the ecological perspective on perception and action, objects and events structure patterned energy distributions such that this structure is specific to its source. Moreover, such structure is invariant over transformations and over particular instances of perceiving. Therefore, the ability to perceive a given functional property is potentially equivalent across both different perceptual modalities and different configurations of the same perceptual modality. We investigated whether this is the case for perception of affordances of a surface that is explored with a part of the body in different contexts. Specifically, we investigated perception of whether an inclined surface could be stood on when the participant explored that surface by stepping onto it with and without bearing weight on the foot. Analyses of the proportion of “yes” responses, the steepest slope angles that were perceived to afford upright stance, and the steepest slope angles that afforded upright stance revealed no differences between perception across the 2 conditions. In particular, there was no difference in perceptual boundaries across the 2 conditions, and neither of these was different from the behavioral boundary. Our findings support the hypothesis that the stimulation patterns supporting perception are invariant across degrees of exploration and are consistent with the hypothesis that the haptic perceptual system is organized as part of a complex biotensegrity system.

Multifractal foundations of visually-guided aiming and adaptation to prismatic perturbation

Visually-guided action of tossing to a target allows examining coordination between mechanical information for maintaining posture while throwing and visual information for aiming. Previous research indicates that relationships between visual and mechanical information persist in tossing behavior long enough for mechanical cues to prompt recall of past visual impressions. Multifractal analysis might model the long-term coordinations among movement components as visual information changes. We asked 32 adult participants (6 female, 25 male, one not conforming to gender binary; aged M=19.77, SD=0.88) to complete an aimed-tossing task in three blocks of ten trials each. Block 1 oriented participants to the task. Participants wore right-shifting goggles in Block 2 and removed them for Block 3. Motion-capture suits collected movement data of the head, hips, and hands. According to regression modeling of tossing performance, multifractality at hand and at hips together supported use of visual information, and adaptation to wearing/removing of goggles depended on multifractality across the hips, head, and hands. Vector-autoregression modeling shows that hip multifractality promoted head multifractality but that hand fluctuations drew on head and hip multifractality. We propose that multifractality could be an information substrate whose spread across the movements systems supports the perceptual coordination for the development of dexterity.

The Anatomy of Action Systems: Task Differentiation When Learning an EMG Controlled Game

This study aims to determine to what extent the task for an action system in its initial development relies on functional and anatomical components. Fifty-two able-bodied participants were randomly assigned to one of three experimental groups or to a control group. As a pre- and post-test all groups performed a computer game with the same goal and using the same musculature. One experimental group also trained to perform this test, while the other two experimental groups learned to perform a game that differed either in its goal or in the musculature used. The observed change in accuracy indicated that retaining the goal of the task or the musculature used equally increased transfer performance relative to controls. Conversely, changing either the goal or the musculature equally decreased transfer relative to training the test. These results suggest that in the initial development of an action system, the task to which the system pertains is not specified solely by either the goal of the task or the anatomical structures involved. It is suggested that functional specificity and anatomical dependence might equally be outcomes of continuously differentiating activity.