A direct comparison of sound and vibration as sources of stimulation for a sensory substitution glove.

Sensory substitution devices (SSDs) facilitate the detection of environmental information through enhancement of touch and/or hearing capabilities. Research has demonstrated that several tasks can be successfully completed using acoustic, vibrotactile, and multimodal devices. The suitability of a substituting modality is also mediated by the type of information required to perform the specific task. The present study tested the adequacy of touch and hearing in a grasping task by utilizing a sensory substitution glove. The substituting modalities inform, through increases in stimulation intensity, about the distance between the fingers and the objects. A psychophysical experiment of magnitude estimation was conducted. Forty blindfolded sighted participants discriminated equivalently the intensity of both vibrotactile and acoustic stimulation, although they experienced some difficulty with the more intense stimuli. Additionally, a grasping task involving cylindrical objects of varying diameters, distances and orientations was performed. Thirty blindfolded sighted participants were divided into vibration, sound, or multimodal groups. High performance was achieved (84% correct grasps) with equivalent success rate between groups. Movement variables showed more precision and confidence in the multimodal condition. Through a questionnaire, the multimodal group indicated their preference for using a multimodal SSD in daily life and identified vibration as their primary source of stimulation. These results demonstrate that there is an improvement in performance with specific-purpose SSDs, when the necessary information for a task is identified and coupled with the delivered stimulation. Furthermore, the results suggest that it is possible to achieve functional equivalence between substituting modalities when these previous steps are met.

Task difficulty and physiological measures of mental workload in air traffic control: a scoping review.

This study provides a systematic synthesis of empirical research on mental workload (MWL) in air traffic control (ATC). MWL is a key concept in research on innovative technologies, because the assessment of MWL is crucial to the evaluation of such technologies. Our specific focus was on physiological measures of MWL. The used search strategy identified 39 peer-reviewed publications that analysed ATC tasks, examined different levels of difficulty of the ATC task, and considered at least one physiological measure of MWL. Positive relations between measures of MWL and task difficulty were observed most frequently, indicating that the measures indeed allowed the assessment of MWL. The most commonly used physiological measures were brain measures (EEG and fNIR) and heart rate measures. The review revealed a need for more precise descriptions of crucial experimental parameters in order to permit a transition of the field towards more interactive and dynamic types of analysis. Practitioner summary: Research on innovative technology in air traffic control (ATC) depends on assessments of mental workload (MWL). We reviewed empirical research on MWL in ATC. Brain and heart measures often allow assessments of MWL. Better descriptions of experiments are needed to allow comparisons among studies and more dynamic and interactive analyses.

Dynamic Touch as Common Ground for Enactivism and Ecological Psychology.

The main purpose of this article is to show that enactivism and ecological psychology share more aspects than is often recognized. Rather than debating about differences, commonalities between the approaches are illustrated with the example of dynamic touch. Dynamic touch is a form of touch that implies muscles and tendons and that allows the perception of hand-held objects that are wielded but not seen. Given that perceivers perform the wielding movements with effort, dynamic touch necessarily implies active exploration. The strength of dynamic touch as an example lies in the fact that it has been formalized and analyzed in detail at the level of the laws that govern the organism-environment system. The example provides empirically supported instantiations of sensorimotor contingencies, in enactivist terms, and of intentional exploration and information detection, in ecological terms. Moreover, dynamic touch is a practical example of the enactivist concepts of bringing-forth the world and sense-making. As a second purpose, we use the example of dynamic touch to clarify key concepts of the ecological approach. Specifically, we analyze the concepts of invariance and affordance, indicating the crucial difference between perceiving and actualizing affordances, and highlighting the importance of these concepts for the dialogue between enactivism and ecological psychology.

Height After Side: Goalkeepers Detect the Vertical Direction of Association-Football Penalty Kicks From the Ball Trajectory.

The present research analyzes the relation between the height of penalty kicks in association football and (a) the probability that goalkeepers stop the ball, (b) the kinematics of the kicker, and (c) the movements of the goalkeeper. We re-analyzed movement registration data that were collected in an experiment (with professional and semi-professional players) that focused on the horizontal direction of the penalties (Lopes et al., 2014). We also digitized and analyzed regular videos of the goalkeepers that were recorded by Lopes et al. (2014) but not analyzed. The present research complements the current understanding of the penalty kick with three main observations. First, goalkeepers save penalties at middle heights more often than low and high penalties. Second, the height of penalties is predicted less clearly than their horizontal direction from the kinematics of penalty takers. Third, goalkeepers tend to initiate the horizontal component of the saving action before the penalty taker contacts the ball, but they initiate the vertical component of the action about 245 ms after the contact. Taken together, these results support the view that goalkeepers make the left-right decision at least partly focusing on the kinematics of the kicker, and that they dynamically decide the vertical aspects of the movement later, focusing on the ball trajectory.

Sensory substitution: The affordance of passability, body-scaled perception, and exploratory movements.

The theory of affordances states that perception is of environmental properties that are relevant to action-capabilities of perceivers. The present study illustrates how concepts and methodological tools from the theory of affordances may help to advance research in the field of sensory substitution. The sensory substitution device (SSD) that was used consisted of two horizontal rows of 12 coin motors that each vibrated as a function of the distance to the nearest object. Sixty blindfolded participants used the SSD to explore virtual horizontal apertures with different widths. They were asked to judge the passability of the apertures. Participants with narrow shoulders judged narrower apertures as passable than participants with wide shoulders. This difference disappeared when aperture width was scaled to shoulder width, demonstrating that perception was body scaled. The actual aperture width was closely related to aspects of the exploratory movements and to aspects of the vibrotactile stimulation that was obtained with the exploratory movements. This implies that the exploratory movements themselves and the vibrotactile stimulation were both informative about the aperture width, and hence that the perception of passability may have been based on either of them or on a global variable that spans vibrotactile as well as kinaesthetic stimulation. Similar performance was observed for participants who accomplished the 7-trial familiarization phase with or without vision, meaning that practice with vision is not indispensable to learn to use the SSD.

The History and Philosophy of Ecological Psychology.

Ecological Psychology is an embodied, situated, and non-representational approach pioneered by J. J. Gibson and E. J. Gibson. This theory aims to offer a third way beyond cognitivism and behaviorism for understanding cognition. The theory started with the rejection of the premise of the poverty of the stimulus, the physicalist conception of the stimulus, and the passive character of the perceiver of mainstream theories of perception. On the contrary, the main principles of ecological psychology are the continuity of perception and action, the organism-environment system as unit of analysis, the study of affordances as the objects of perception, combined with an emphasis on perceptual learning and development. In this paper, first, we analyze the philosophical and psychological influences of ecological psychology: pragmatism, behaviorism, phenomenology, and Gestalt psychology. Second, we summarize the main concepts of the approach and their historical development following the academic biographies of the proponents. Finally, we highlight the most significant developments of this psychological tradition. We conclude that ecological psychology is one of the most innovative approaches in the psychological field, as it is reflected in its current influence in the contemporary embodied and situated cognitive sciences, where the notion of affordance and the work of E. J. Gibson and J. J. Gibson is considered as a historical antecedent.

Sensory substitution: Using a vibrotactile device to orient and walk to targets.

This study investigates how active exploration helps users of sensory substitution devices (SSDs) to detect action-relevant information. A vibrotactile SSD was developed that generates stimulation that is contingent on the users' movements. Target direction was specified by the location of the vibratory stimulation, and target distance by the size and intensity of the pattern of stimulation. A series of experiments was performed with blindfolded participants. In Experiments 1a to 1c, participants used the SSD to align their central body axis with prespecified targets. These experiments differed in the number of actuators that were used and whether online perception-action coupling was present. In Experiment 2, participants approached targets with forward locomotion along a straight line. Experiment 3 combined the previous experiments and studied the concomitant walking and steering toward targets. Oscillatory movements, which facilitated information pickup, were observed in all experiments. The exploratory oscillations were shown to depend on the online perception-action coupling and were related to cases of hyperacuity, for which absolute errors were found to be smaller than the areas of sensitivity of the actuators. It is concluded that, to improve the utility of SSDs, future research with SSDs should pay more attention to the role of active information detection. (PsycINFO Database Record

Body-scaled affordances in sensory substitution.

The research field on sensory substitution devices has strong implications for theoretical work on perceptual consciousness. One of these implications concerns the extent to which the devices allow distal attribution. The present study applies a classic empirical approach on the perception of affordances to the field of sensory substitution. The reported experiment considers the perception of the stair-climbing affordance. Participants judged the climbability of steps apprehended through a vibrotactile sensory substitution device. If measured with standard metric units, climbability judgments of tall and short participants differed, but if measured in units of leg length, judgments did not differ. These results are similar to paradigmatic results in regular visual perception. We conclude that our sensory substitution device allows the perception of affordances. More generally, we argue that the theory of affordances may enrich theoretical debates concerning sensory substitution to a larger extent than has hitherto been the case.

Stepping on obstacles with a sensory substitution device on the lower leg: practice without vision is more beneficial than practice with vision.

Practice is essential for an adapted use of sensory substitution devices. Understanding the learning process is therefore a fundamental issue in this field of research. This study presents a novel sensory substitution device worn on the lower leg and uses the device to study learning. The device includes 32 vibrotactile actuators that each vibrate as a function of the distance to the nearest surface in a particular direction. Participants wearing the device were asked to approach an object and to step on the object. Two 144-trial practice conditions were compared in a pretest-practice-posttest design. Participants in the first condition practiced with vibrotactile stimulation while blindfolded. Participants in the second condition practiced with vibrotactile stimulation along with normal vision. Performance was relatively successful, both types of practice led to improvements in performance, and practice without vision led to a larger reduction in the number of errors than practice with vision. These results indicate that distance-based sensory substitution is promising in addition to the more traditional light-intensity-based sensory substitution and that providing appropriate sensorimotor couplings is more important than applying the stimulation to highly sensitive body parts. The observed advantage of practice without vision over practice with vision is interpreted in terms of the guidance hypothesis of feedback and learning.

Predicting the lateral direction of deceptive and non-deceptive penalty kicks in football from the kinematics of the kicker.

This study addresses the utility of the kinematics of penalty takers for goalkeepers in association football. Twelve professional and semi-professional players shot to one side of the goal with (deceptive condition) or without (non-deceptive condition) simulating a shot to the opposite side. The body kinematics of the penalty takers were registered with motion-capture apparatus. Correlation and regression techniques were used to determine the relation between the shot direction and aspects of the penalty taker's kinematics at different moments. Several kinematic variables were strongly correlated with shot direction, especially those related to the lower part of the body. Some of these variables, including the angle of the non-kicking foot, acquired high correlations at time intervals that are useful to goalkeepers. Compound variables, here defined as linear combinations of variables, were found to be more useful than locally defined variables. Whereas some kinematic variables showed substantial differences in their relation to ball direction depending on deception, other kinematic variables were less affected by deception. Results are interpreted with the hypothesis of non-substitutability of genuine action. The study can also be interpreted as extending the correlation and regression methodology, often used to analyze variables defined at single moments, to the analysis of variables in a time continuous fashion.

Action-contingent vibrotactile flow facilitates the detection of ground level obstacles with a partly virtual sensory substitution device.

This research considers a sensory substitution device that allows the exploration of the environment through normal walking, leaning and standing. The device includes an array of 24 coin motors placed vertically on the torso, with the intensity of vibration of each motor being a function of the distance to the first-encountered object. Thresholds were determined for the detection of ground-level obstacles (raised target platforms). On average, blindfolded participants were able to detect platforms with heights of 9 to 17 cm, but the thresholds differed for different experimental conditions. Experiment 1 showed that the detection threshold is lower for use with exploratory movements than for use without exploratory movements. Experiments 2 and 3 compared dynamic groups, who made exploratory movements and received vibrotactile flow contingent on their movements, with yoked groups, who received the same vibrotactile flow as the dynamic groups independently of their own movements. The detection thresholds were lower for the dynamic groups than for the yoked groups, meaning that the contingency of vibrotactile flow on exploratory movements is important beyond a higher-order vibrotactile flow by itself.

El patrón de exploración modula la percepción de longitudes a través del tacto dinámico / Exploration styles modulate length perception through dynamic touch

Una de las habilidades más sorprendentes del sistema háptico es su capacidad de realizar estimaciones de algunas propiedades de los objetos, como el peso o el tamaño, utilizando invariantes de la mecánica rotacional que son accesibles por medio del subsistema propioceptivo; este campo de investigación se denomina tacto dinámico. En un ejemplo clásico de este paradigma experimental, el participante sujeta una varilla en su mano, sin estar ésta a la vista, y trata de igualar el tamaño percibido usando otra varilla que puede ver pero no blandir. En este experimento analizamos el papel del comportamiento exploratorio en esta situación, restringiendo el balanceo de la varilla en seis condiciones que varían la frecuencia y amplitud de los movimientos. Los resultados muestran que con una mayor velocidad en los movimientos se incrementa el ajuste de las estimaciones hápticas. Por ello, se argumenta que el momento de inercia es el mejor candidato informacional al realizar la tarea, ya que es una propiedad invariante que emerge únicamente cuando se aplica fuerza y se realizan movimientos rotacionales con el objeto. Se descartan otros candidatos informacionales, como el momento estático, o la masa, dado que no dependen de movimientos diferenciales (AU)

One of the most surprising capacities of the haptic system is the ability to estimate different properties of objects, like weight or length, through invariants of rotational mechanics that are accessible via the proprioceptive system. This field of research is called Dynamic Touch. In its classical experimental paradigm, the participant firmly grasps a rod that can be wielded but not seen, and he or she tries to match the hand-held rod’s length using another rod that can be seen but not wielded. In the experiment reported here, we focus on the role of the exploratory behavior, restricting the wielding in six conditions that vary both the amplitude and the frequency of movements. Increments in the speed of the movement are shown to increase the accuracy in the haptic estimation. It is argued that these results support the moment of inertia as the best informational candidate, given that it is an invariant property that only emerges when rotational torques are applied. Alternative candidates such as static moment or mass are discarded because they do not depend on differential movements (AU)

[Exploration styles modulate length perception through dynamic touch]. / El patrón de exploración modula la percepción de longitudes a través del tacto dinámico.

One of the most surprising capacities of the haptic system is the ability to estimate different properties of objects, like weight or length, through invariants of rotational mechanics that are accessible via the proprioceptive system. This field of research is called Dynamic Touch. In its classical experimental paradigm, the participant firmly grasps a rod that can be wielded but not seen, and he or she tries to match the hand-held rod's length using another rod that can be seen but not wielded. In the experiment reported here, we focus on the role of the exploratory behavior, restricting the wielding in six conditions that vary both the amplitude and the frequency of movements. Increments in the speed of the movement are shown to increase the accuracy in the haptic estimation. It is argued that these results support the moment of inertia as the best informational candidate, given that it is an invariant property that only emerges when rotational torques are applied. Alternative candidates such as static moment or mass are discarded because they do not depend on differential movements.

El enfoque neogibsoniano como marco conceptual y metodológico para el diseño de programas de entrenamiento deportivo / Neogibsonian approach as conceptual and methodological framework for the design of trainig programs in sports

Según el enfoque neogibsoniano, el aprendizaje perceptivo y perceptivo-motor es un proceso que consiste en mejorar la detección y el uso de la abundante información que existe en el ambiente. Ésta afirmación es el punto de partida de un marco conceptual y metodológico para el análisis del aprendizaje que incluye los conceptos de educación de la atención y calibración y, más recientemente, las nociones de espacio informacional, del aprendizaje por función potencial y del aprendizaje directo. En este artículo se introduce el enfoque neogibsoniano y se describen las implicaciones de dicho enfoque en el diseño de programas de entrenamiento. En particular, se plantea una explicación de por qué la introducción de variabilidad en el entrenamiento facilita la mejora en el rendimiento deportivo, y propuestas concretas de cómo ha de introducirse tal variabilidad para que sea beneficiosa (AU)

The neogibsonian approach holds that the processes of perceptual and perceptual-motor learning consist of improving the detection and use of the abundant information that exists in task environments. This claim is the starting point for a conceptual and methodological framework used for the analysis of learning. The conceptual framework includes the concepts of the education of attention and calibration and, more recently, the ones of potential-based and direct learning. The present article introduces the neogibsonian approach and describes the implications of that approach for the design of training programs. In particular, the article addresses an explanation for the beneficial effects of variability in practice methods, and it considers the way in which variability should be introduced so as to achieve the beneficial effects (AU)

Performance in haptic geometrical matching tasks depends on movement and position of the arms.

Previous research on the properties of haptic space has shown systematic deviations from Euclidean parallelity in haptic parallelity tasks. The mainstream explanation for these deviations is that, in order to perform the task, participants generate a spatial representation with a frame of reference that integrates egocentric and allocentric components. Several studies have shown that the amount and type of deviations are affected by the configurations with regard to the arms and the rods to be matched. The present study reports 4 experiments that further address the effects of task configurations and body movements. Experiments 1 and 2 replicate and extend previous results concerning haptic matching task and acoustic pointing tasks. The third experiment includes acoustic cues aligned differentially to the reference and test bars. The fourth experiment concerns a geometrical matching task performed in the rear peripersonal space. Results show that haptic deviations from the Euclidean space are modulated by the available cues and by the body configurations. This indicates the need for further analysis on the role of body, arm and shoulder positions, and movement effects in haptic space perception.

The ecological level of analysis: can neogibsonian principles be applied beyond perception and action?

Is it useful to apply ecological principles, developed to understand perception and action, in research areas such as social psychology? Charles (Integrative Psychological & Behavioral Sciences 43(1) 53-66 2009) warns ecological psychologists interested in this question that much time and effort can be saved through a backwards extension to or rediscovery of the New Realism tradition. In response, we analyze what ecological psychology risks to lose with such a backwards extension and describe existing extensions of the approach not considered by Charles. According to Charles, New Realism holds that: (1) we experience reality, (2) relations are real, and (3) things are what you see when you see those things. Our arguments originate from a comparison of these principles with six recently described ecological ones: (1) organism-environment systems are the proper units of analysis, (2) environmental realities should be defined at the ecological scale, (3) behavior is emergent and self-organized, (4) perception and action are continuous and cyclic, (5) information is specificational, and (6) perception is of affordances (Richardson et al. 2008).

Assessing subclinical tactual deficits in the hand function of diabetic blind persons at risk for peripheral neuropathy.

OBJECTIVE: To assess subclinical impairments in tactual hand function produced by diabetes mellitus in late-blind adults with diabetic retinopathy. DESIGN: The survey compares diabetic blind with nondiabetic blind and blindfolded sighted controls in terms of their performance on a battery of tests that assess tactual hand function. SETTING: Subjects were evaluated at their rehabilitation program center in Madrid. PARTICIPANTS: Nine (referred) diabetic blind subjects affected by diabetic retinopathy versus 10 (referred) nondiabetic blind subjects versus 10 blindfolded sighted volunteers, all right-handed and matched for age. Subjects were referred by the training professionals of the rehabilitation program center and asked to volunteer. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Cutaneous force and spatial resolution thresholds, haptic psychophysical functions for perceived roughness, weight, and size, and both accuracy and response times for haptic classification of 3-dimensional common objects. Measures of joint mobility, muscular strength, and motor dexterity were also included. RESULTS: The diabetic blind performed significantly poorer than the controls in terms of force sensitivity (distal and proximal finger pads, and palm), spatial resolution (distal finger pad only), motor dexterity, perceived roughness, and finally, haptic object classification response times for texture-diagnostic objects. CONCLUSIONS: Subclinical disturbances in the tactual hand function of the diabetic blind subjects were only documented in perceptual and motor tasks for which cutaneous, as opposed to kinesthetic, information was particularly relevant.