Motor adaptation in deaf and hearing native signers.

Previous studies have suggested that deafness could lead to deficits in motor skills and other body-related abilities. However, the literature regarding motor skills in deaf adults is scarce and existing studies often included participants with heterogeneous language backgrounds and deafness etiologies, thus making it difficult to delineate the effects of deafness. In this study, we investigated motor learning in deaf native signers and hearing nonsigners.

Child development and the role of visual experience in the use of spatial and non-spatial features in haptic object perception.

Previous work has suggested a different developmental timeline and role of visual experience for the use of spatial and non-spatial features in haptic object recognition. To investigate this conjecture, we used a haptic ambiguous odd-one-out task in which one object needed to be selected as being different from two other objects. The odd-one-out could be selected based on four characteristics: size, shape (spatial), texture, and weight (non-spatial).

Longing for touch post-COVID-19: current observations and future directions.

Previous studies have reported an association between the COVID-19 pandemic, social distancing regulations and longing for touch (LFT; i.e., a discrepancy between actual touch frequency and one's desire to be touched).

Correction: Reward abundance interferes with error-based learning in a visuomotor adaptation task.

[This corrects the article DOI: 10.1371/journal.pone.

Gamification as a Sustainable Source of Enjoyment During Balance and Gait Exercises.

We may be motivated to engage in a certain motor activity because it is instrumental to obtaining reward (e.g., money) or because we enjoy the activity, making it intrinsically rewarding.

Reward abundance interferes with error-based learning in a visuomotor adaptation task.

The brain rapidly adapts reaching movements to changing circumstances by using visual feedback about errors. Providing reward in addition to error feedback facilitates the adaptation but the underlying mechanism is unknown. Here, we investigate whether the proportion of trials rewarded (the 'reward abundance') influences how much participants adapt to their errors.

Haptic two-dimensional shape identification in children, adolescents, and young adults.

We investigated the influence of image mediation (the process that translates tactile information into a visual image) on the development of haptic two-dimensional (2D) shape identification in 78 participants from five different age groups: preschoolers (4-5 years), first graders (6-7 years), fifth graders (10-11 years), young adolescents (12-13 years), and young adults (18-28 years). Participants attempted to haptically recognize everyday objects (three-dimensional [3D] haptic condition) and tangible line drawings (2D haptic condition) and to recognize objects presented through a serial visual "peek hole" version of the haptic line drawing task (2D visual condition). All groups were excellent at 3D haptic identification.

Haptic search for movable parts.

How do we know that we are touching 1 single object instead of 2 different ones? An important cue is movability: When different sources of input can move independently, it is likely that they belong to different objects or that the object consists of movable parts. We hypothesize that the haptic feature "movability" is used for making this differentiation and we expect movability to be detected efficiently. We investigated this hypothesis by using a haptic search task.

Temporally stable adaptation is robust, incomplete and specific.

Sensorimotor adaptation, the process that reduces movement errors by learning from sensory feedback, is often studied within a session of about half an hour. Within such a single session, adaptation generally reaches plateau before errors are completely removed. However, adaptation may complete on longer timescales: the slow components of error-based adaptation are associated with good retention.

Perceptual Grouping Affects Haptic Enumeration Over the Fingers.

Spatial arrangement is known to influence enumeration times in vision. In haptic enumeration, it has been shown that dividing the total number of items over the two hands can speed up enumeration. Here we investigated how spatial arrangement of items and non-items presented to the individual fingers impacts enumeration times.

The effects of aging on haptic 2D shape recognition.

We use the image-mediation model (Klatzky & Lederman, 1987) as a framework to investigate potential sources of adult age differences in the haptic recognition of two-dimensional (2D) shapes. This model states that the low-resolution, temporally sequential, haptic input is translated into a visual image, which is then reperceived through the visual processors, before it is matched against a long-term memory representation and named. In three experiments we tested groups of 12 older (mean age 73.

Grouping by proximity in haptic contour detection.

We investigated the applicability of the Gestalt principle of perceptual grouping by proximity in the haptic modality. To do so, we investigated the influence of element proximity on haptic contour detection. In the course of four sessions ten participants performed a haptic contour detection task in which they freely explored a haptic random dot display that contained a contour in 50% of the trials.

Perceptual grouping in haptic search: the influence of proximity, similarity, and good continuation.

We conducted a haptic search experiment to investigate the influence of the Gestalt principles of proximity, similarity, and good continuation. We expected faster search when the distractors could be grouped. We chose edges at different orientations as stimuli because they are processed similarly in the haptic and visual modality.

Somatosensory saccades reveal the timing of tactile spatial remapping.

Remapping tactile events from skin to external space is an essential process for human behaviour. It allows us to refer tactile sensations to their actual externally based location, by combining anatomically based somatosensory information with proprioceptive information about the current body posture. We examined the time course of tactile remapping by recording speeded saccadic responses to somatosensory stimuli delivered to the hands.

Integration of tactile input across fingers in a patient with finger agnosia.

Finger agnosia has been described as an inability to explicitly individuate between the fingers, which is possibly due to fused neural representations of these fingers. Hence, are patients with finger agnosia unable to keep tactile information perceived over several fingers separate? Here, we tested a finger agnosic patient (GO) on two tasks that measured the ability to keep tactile information simultaneously perceived by individual fingers separate. In experiment 1 GO performed a haptic search task, in which a target (the absence of a protruded line) needed to be identified among distracters (protruded lines).

I can't believe this isn't wood! An investigation in the perception of naturalness.

For most people "naturalness" is a highly appreciated material characteristic. For instance, a natural wooden floor is seen as more valuable than a fake replica, though they may be comparable in quality and durability. In the present study we investigated how sensory input (vision and touch) contributes to the perception of naturalness in wood.

Serial search for fingers of the same hand but not for fingers of different hands.

In most haptic search tasks, tactile stimuli are presented to the fingers of both hands. In such tasks, the search pattern for some object features, such as the shape of raised line symbols, has been found to be serial. The question is whether this search is serial over all fingers irrespective of the hand, or whether it is serial over the fingers of each hand and parallel over the two hands.