Intrinsic somatosensory feedback supports motor control and learning to operate artificial body parts.

Objective.Considerable resources are being invested to enhance the control and usability of artificial limbs through the delivery of unnatural forms of somatosensory feedback. Here, we investigated whether intrinsic somatosensory information from the body part(s) remotely controlling an artificial limb can be leveraged by the motor system to support control and skill learning.Approach.We used local anaesthetic to attenuate somatosensory inputs to the big toes while participants learned to operate through pressure sensors a toe-controlled and hand-worn robotic extra finger. Motor learning outcomes were compared against a control group who received sham anaesthetic and quantified in three different task scenarios: while operating in isolation from, in synchronous coordination, and collaboration with, the biological fingers.Main results.Both groups were able to learn to operate the robotic extra finger, presumably due to abundance of visual feedback and other relevant sensory cues. Importantly, the availability of displaced somatosensory cues from the distal bodily controllers facilitated the acquisition of isolated robotic finger movements, the retention and transfer of synchronous hand-robot coordination skills, and performance under cognitive load. Motor performance was not impaired by toes anaesthesia when tasks involved close collaboration with the biological fingers, indicating that the motor system can close the sensory feedback gap by dynamically integrating task-intrinsic somatosensory signals from multiple, and even distal, body-parts.Significance.Together, our findings demonstrate that there are multiple natural avenues to provide intrinsic surrogate somatosensory information to support motor control of an artificial body part, beyond artificial stimulation.

Laterality of expression in portraiture: putting your best cheek forward.

Portraits, both photographic and painted, are often produced with more of one side of the face showing than the other. Typically, the left side of the face is overrepresented, with the head turned slightly to the sitter's right. This leftward bias is weaker for painted male portraits and non-existent for portraits of scientists from the Royal Society. What mechanism might account for this bias? Examination of portraits painted by left- and right-handers and of self-portraits suggests that the bias is not determined by a mechanical preference of the artist or by the viewer's aesthetics. The leftward bias seems to be determined by the sitters and their desire to display the left side of their face, which is controlled by the emotive, right cerebral hemisphere. When we asked people to portray as much emotion as possible when posing for a family portrait, they tended to present the left side of their face. When asked to pose as scientists and avoid portraying emotion, participants tended to present their right side. The motivation to portray emotion, or conceal it, might explain why portraits of males show a reduced leftward bias, and also why portraits of scientists from the Royal Society show no leftward bias.

Handedness in opposite and same-sex dizygotic twins: testing the testosterone hypothesis.

Prenatal exposure to testosterone is proposed to promote development of the right hemisphere and increase the incidence of sinistrality. This proposition was tested by comparing the hand preference of 59 opposite-sex and 61 same-sex dizygotic twins. Because testosterone is thought to pass between twins in utero, it was predicted that females with a male twin would show a high incidence of sinistrality compared to females with a female twin. Similarly, it was predicted that males with a male twin would be more likely to be sinistral than males with a female twin. Measures of the strength of hand preference and the incidence of sinistrality revealed no difference between the opposite and same-sex twins for either sex. The data also failed to confirm reports that first-born twins are more likely to be sinistral than second-born twins. These data add to a growing body of research which is critical of the testosterone hypothesis.

A failure to produce a left hemisphere advantage through verbal priming.

The proposition that visual field asymmetries can be produced through priming the left hemisphere with verbal material was investigated. In the first experiment a two-choice neutral detection task was established to measure biases of attention between the visual fields. In the second experiment, a priming effect was achieved by superimposing each trial with a verbal recognition task. Reaction time and error measures showed no sign of a right visual field advantage. In the third experiment, the neutral detection trials were intermixed with trials associated with a word recognition task. A significant right visual field advantage was found for the word recognition task. However, this pattern of asymmetry was not found for the neutral detection task. In the fourth experiment the level of difficulty associated with neutral detection task was increased. The effect of expectancy was investigated by manipulating the proportion of neutral and verbal stimuli. Despite these manipulations, the pattern of results was essentially the same as those observed in the previous experiment. These experiments demonstrate that verbal priming does not affect the distribution of spatial attention.

Colonially breeding seabirds: Predators or prey?

The evolution of aggregation in seabirds is usually attributed to predation pressure, although many authors have argued for the role of foraging constraints to be considered. Discriminating between factors that result in group living and characteristics arising from group living has been regarded as an insoluble problem; yet it is possible to test the predictions of the different models proposed to explain colonial nesting. The resulting explanation suggests that seabird aggregations have evolved in order to utilize a dispersed and unpredictable food supply. As such, colonial nesting leads to increased vulnerability to predation, rather than being a strategy adopted to combat it.

Health administration: the wealth and welfare wager.

Taking resources away from the NHS is not an easy thing to do, as the outraged cries of protest against the cuts over the past few months have testified. But hand in hand with this process has been the Government's determination to find new ways of putting money back into the service. Drew Clode examines some of the local approaches to fund raising so warmly espoused by the DHSS and examines how successful similar schemes have been when tried out in local government.

Health administration: service before self, but . . . what about pay?

Author peers throuth the 'perpetual fog' that is pay--pay policy, pay restraint, pay freeze--to try to discern the way wages are negotiated, the 'lumpy' aspect of the structure and the problems of job evaluation and reward; matters which, he says, will keep Whitley in steady and altruistically gainful employment for some time to come.

Health administration: the war that is waged even after the wage war is over.

Conditions are made in every job. It is quite another exercise meeting them. Galling things like telephone rental money; malignant little ulcers like removal expenses; the kind of friction that ensues when, having been promised the moon, you get a handful of dust. Drew Clode, who last week looked into wage packets, now tests the letter and the spirit of something more abstract if no less realistic: the conditions in which you work and indeed live.

Circling the pyramid by camel--via the needle's eye.

The Royal Commission's report on the NHS criticised the lack of central manpower planning advice for the nursing profession as well as dwelling at some length on the difficulties that the hospital career structure poses medical manpower planners. The most damaging disadvantage of the DHSS's approach to the latter issue is, says the Commission, 'that it has not delivered the goods'. Author examines manpower problems as they affect both professions.

Health administration: planning: push-button age.

With the development of strategic and operational planning in the NHS, the demands for techniques for gauging manpower implications have grown increasingly loud. At the same time the rise in labour costs has renewed interest in planning the use of NHS skills more purposefully. In the first of two articles (the second will appear in the near future) on the topic, Drew Clode examines some of the methods available nationally for collecting personnel data.

Health Administration: of fleas and smaller fleas...

Monitoring as an official management tool has been a source of discontent since its introduction with reorganisation. Normal pride in a job well done is replaced by tension over monitoring being a negative and censorious act of interference. Drew Clode reports on some schemes that aim to make it a participatory and constructive exercise.

The health thinkers: clarifying health determinants but not upsetting sinners.

Probably no health thinker has played a greater part than Professor Tom McKeown in bringing medical practice in modern society under close and critical scrutiny. He has accomplished this not by a ruthless assessment of individual clinical therapies, but by linking the role of medicine to the wider issues within epidemiology.

Industrial relations: the personnel challenge.

The NHS has been lagging in industrial relations compared with other industries. In an attempt to correct this, greater emphasis is now being placed in IR training for personnel staff. In addition, there is a trend towards separate IR officers. Author looks at the developments.