Application of the rubber hand illusion paradigm: comparison between upper and lower limbs.

The "rubber hand illusion (RHI)" is a perceptual illusion, which allows the integration of artificial limbs into the body representation of a person by means of combined visual and tactile stimulation. The illusion has been frequently replicated but always concerning the upper limbs. The present study verified an analog illusion that can be called the "rubber foot illusion" (RFI).

Energy management that generates terrain following versus apex-preserving hopping in man and machine.

While hopping, 12 subjects experienced a sudden step down of 5 or 10 cm. Results revealed that the hopping style was "terrain following". It means that the subjects pursued to keep the distance between maximum hopping height (apex) and ground profile constant.

Inverse biomimetics: how robots can help to verify concepts concerning sensorimotor control of human arm and leg movements.

Simulation test, hardware test and behavioral comparison test are proposed to experimentally verify whether a technical control concept for limb movements is logically precise, physically sound, and biologically relevant. Thereby, robot test-beds may play an integral part by mimicking functional limb movements. The procedure is exemplarily demonstrated for human aiming movements with the forearm: when comparing competitive control concepts, these movements are described best by a spring-like operating muscular-skeletal device which is assisted by feedforward control through an inverse internal model of the limb--without regress to a forward model of the limb.

Disfluency data of German preschool children who stutter and comparison children.

Unlabelled: This study compared the disfluencies of German-speaking preschool children who stutter (CWS, N = 24) with those produced by age- and sex-matched comparison children who do not stutter (CWNS, N = 24). In accordance with Yairi and Ambrose's [Yairi, E., & Ambrose, N.

Threading neural feedforward into a mechanical spring: how biology exploits physics in limb control.

A solution is proposed of the hitherto unsolved problem as to how neural feedforward through inverse modelling and negative feedback realised by a mechanical spring can be combined to achieve a highly effective control of limb movement. The revised spring approach that we suggest does not require forward modelling and produces simulated data which are as close as possible to experimental human data. Control models based on peripheral sensing with forward modelling, which are favoured in the current literature, fail to create such data.

Linguistic stress, within-word position, and grammatical class in relation to early childhood stuttering.

Unlabelled: The purpose of the present study was to investigate whether the link that has been established between stuttering and linguistic stress in adolescents and adults (the so-called stress effect) can also be observed in childhood stuttering. To account for confounding variables, both within-word position and grammatical class were measured, because these factors covary with linguistic stress. Speech samples of 22 preschool children (mean time of 9 months since onset of stuttering) were analyzed.

Adaptive motor behavior of cerebellar patients during exposure to unfamiliar external forces.

The authors investigated adaptation of goal-directed forearm movements to an unknown external viscous force assisting forearm flexion in 6 patients with cerebellar dysfunction and in 6 control participants. Motor performance was generally degraded in cerebellar patients and was markedly reduced under the force condition in both groups. However, patients and controls were able to adapt to the novel force within 8 trials.

Control of voice fundamental frequency in speaking versus singing.

In order to investigate control of voice fundamental frequency (F0) in speaking and singing, 24 adults had to utter the nonsense word ['ta:tatas] repeatedly, while in selected trials their auditory feedback was frequency-shifted by 100 cents downwards. In the speaking condition the target speech rate and prosodic pattern were indicated by a rhythmic sequence made of white noise. In the singing condition the sequence consisted of piano notes, and subjects were instructed to match the pitch of the notes.

The duration component of the stress effect in stuttering.

Unlabelled: The purpose of the present study was to investigate whether there is a relationship between stuttering on stressed syllables and the duration of these syllables. Sixteen adults who stutter read a text consisting of 226 syllables. The relative stress of each syllable was rated, and syllables were categorized into long- and short-stressed syllables, unstressed syllables and intermediate syllables lying in-between.

Effects of frequency-shifted auditory feedback on voice F0 contours in syllables.

Previous studies have shown that, during continuous vocalization, voice fundamental frequency (voice F0) is modified by frequency-shifted auditory feedback. In this study, the effects of frequency-shifted auditory feedback on voice F0 contours were determined for the first two syllables of the nonsense word [tatatas]. Results show that voice F0 is auditorily controlled with a long latency and responses are not interrupted by the onset and offset of phonation itself.