The maturation of cutaneous reflexes studied in the upper limb in man.

Issler, H; Stephens, John A.

doi:10.1113/jphysiol.1983.sp014556

Cited by 64 publications

(40 citation statements)

References 20 publications

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“…The latency of the following sharp burst, also triggered by the start of the slip, is in agreement with the long-latency excitatory response seen in cutaneomuscular reflex experiments (see the discussion above and (Evans et al 1990(Evans et al , 1991Issler and Stephens 1983;Jenner and Stephens 1982)). The response latencies (43 Ϯ 17 ms) for the burst in primary motor neurons in the monkey discussed in the preceding text (Bourdreau and Smith 2001;Picard and Smith 1992b) were similar to our data (44 Ϯ 18 ms).…”

Section: Model and Behavior Suggests Supraspinal Controlsupporting

confidence: 86%

“…Studies on cutaneomuscular reflex responses (Deuschl et al 1995;Issler and Stephens 1983;Jenner and Stephens 1982) indicate a spinal latency of 30 -50 ms, and a long latency of 55-75 ms with possible cortical involvement, for a review see Cruccu and Deuschl (2000). Triggered reactions (80 -120 ms), which can be elicited from various receptors and act on associated musculature (Cargo et al 1976;Johansson and Westling 1984b;1988b;Schmidt and Lee, 1999), involve higher centers and fit well with the functional nature of the GF increase studied here.…”

Section: Model and Behavior Suggests Supraspinal Controlmentioning

confidence: 99%

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Control Strategies Correcting Inaccurately Programmed Fingertip Forces: Model Predictions Derived From Human Behavior

Fagergren

Ekeberg²,

Forssberg³

2003

Journal of Neurophysiology

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Fagergren, Anders, Ö rjan Ekeberg, and Hans Forssberg. Control strategies correcting inaccurately programmed fingertip forces: model predictions derived from human behavior. J Neurophysiol 89: 2904-2916, 2003. First published February 12, 2003 10.1152/jn.00939.2002. When picking up a familiar object between the index finger and the thumb, the motor commands are predetermined by the CNS to correspond to the frictional demand of the finger-object contact area. If the friction is less than expected, the object will start to slip out of the hand, giving rise to unexpected sensory information. Here we study the correction strategies of the motor system in response to an unexpected frictional demand. The motor commands to the mononeuron pool are estimated by a novel technique combining behavioral recordings and neuromuscular modelling.We first propose a mathematical model incorporating muscles, hand mechanics, and the action of lifting an object. A simple control system sends motor commands to and receives sensory signals from the model. We identify three factors influencing the efficiency of the correction: the time development of the motor command, the delay between the onset of the grip and load forces (GF-LF-delay), and how fast the lift is performed. A sensitivity analysis describes how these factors affect the ability to prevent or stop slipping and suggests an efficient control strategy that prepares and corrects for an altered frictional condition.We then analyzed fingertip grip and load forces (GF and LF) and position data from 200 lifts made by five healthy subjects. The friction was occasionally reduced, forcing an increase of the GF to prevent the object being dropped. The data were then analyzed by feeding it through the inverted model. This provided an estimate of the motor commands to the motoneuron pool.As suggested by the sensitivity analysis the GF-LF-delay was indeed used by the subjects to prevent slip. In agreement with recordings from neurons in the primary motor cortex of the monkey, a sharp burst in the estimated GF motor command (NGF) efficiently arrested any slip. The estimated motor commands indicate a control system that uses a small set of corrective commands, which together with the GF-LF-delay form efficient correction strategies. The selection of a strategy depends on the amount of tactile information reporting unexpected friction and how long it takes to arrive. We believe that this technique of estimating the motor commands behind the fingertip forces during a precision grip lift can provide a powerful tool for the investigation of the central control of the motor system.

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Section: Model and Behavior Suggests Supraspinal Controlsupporting

confidence: 86%

Section: Model and Behavior Suggests Supraspinal Controlmentioning

confidence: 99%

Control Strategies Correcting Inaccurately Programmed Fingertip Forces: Model Predictions Derived From Human Behavior

Fagergren

Ekeberg²,

Forssberg³

2003

Journal of Neurophysiology

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“…The development of cutaneous reflexes shows a similar pattern to that of the phasic stretch reflex, with an increasing threshold with age (Fitzgerald, Shaw & MacIntosh, 1988) and a decreasing magnitude of the early component of the response evoked by a standard stimulus over the first year (Issler & Stephens, 1983 (Gregory & Proske, 1988). In the cat Skoglund (1960) demonstrated rapidly adapting responses to stretch at birth, and Gregory & Proske (1988) noted increased sensitivity and rate of firing of muscle spindle afferents to standard muscle stretch with increasing age, which would suggest the reverse of an increase of threshold.…”

Section: Discussionmentioning

confidence: 92%

Radiation of phasic stretch reflex in biceps brachii to muscles of the arm in man and its restriction during development.

O’Sullivan

Eyre

Miller

1991

The Journal of Physiology

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SUMMARY1. The phasic stretch reflex in biceps brachii has been recorded in 372 normal subjects aged from 31 weeks gestation to 55 years. The stimulus used was a brief mechanical pulse delivered by a hand-held electromagnetic vibrator and the response was measured in the surface electromyogram.2. The threshold for eliciting the reflex was low in the newborn and increased over the first 6 years to values corresponding to those of adults.3. On the basis of timing it is concluded that the phasic stretch reflex has a monosynaptic component at all ages.4. The surface electromyogram was also recorded in triceps brachii, pectoralis major, deltoid and hypothenar muscles. In some subjects evoking the phasic stretch reflex in biceps brachii resulted in short latency responses in these muscles, a phenomenon termed radiated response.5. The probability of occurrence of radiated responses and their magnitudes were greatest at birth and decreased over 2-4 years.6. Experiments were performed to determine how far mechanical transmission of the stimulus to biceps through the tissues of the arm might account for the radiated responses in the other muscles studied. It was concluded that the responses observed in triceps brachii, pectoralis major, deltoid and hypothenar muscles, following vibration of the biceps tendon, are primarily due to the radiation of the activity carried in biceps muscle afferents to the a-motoneurones of the respective muscles.7. On the basis of timing it is concluded that in subjects below 2 years the radiated responses in the muscles studied have a monosynaptic component.

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“…In both of the age groups tested here, the majority of visual and manual responses measured emerged between 1 and 4 seconds after stimulus presentation (see Figure 2). The latency of these responses argues against a spinal reflex, as the muscular activity associated with cutaneous spinal reflex responses is typically observed at a latency of around 20 ms, even in the newborn infant (see Issler & Stephens, 1983). Another indication that these responses were under cortical control comes from the comparison of the speed of 6.5-month-olds' responses against that of a baseline group who were not presented with any vibrotactile stimulation (Experiment 2).…”

Section: Discussionmentioning

confidence: 99%

Spatial localization of touch in the first year of life: Early influence of a visual spatial code and the development of remapping across changes in limb position.

Bremner¹,

Mareschal²,

Lloyd‐Fox³

et al. 2008

Journal of Experimental Psychology: General

123

131

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Two experiments investigated infants' ability to localize tactile sensations in peripersonal space. Infants aged 10 months (Experiment 1) and 6.5 months (Experiment 2) were presented with vibrotactile stimuli unpredictably to either hand while they adopted either a crossed-or uncrossed-hands posture. At 6.5 months, infants' responses were predominantly manual, whereas at 10 months, visual orienting behavior was more evident. Analyses of the direction of the responses indicated that (a) both age groups were able to locate tactile stimuli, (b) the ability to remap visual and manual responses to tactile stimuli across postural changes develops between 6.5 and 10 months of age, and (c) the 6.5-month-olds were biased to respond manually in the direction appropriate to the more familiar uncrossed-hands posture across both postures. The authors argue that there is an early visual influence on tactile spatial perception and suggest that the ability to remap visual and manual directional responses across changes in posture develops between 6.5 and 10 months, most likely because of the experience of crossing the midline gained during this period.

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The maturation of cutaneous reflexes studied in the upper limb in man.

Cited by 64 publications

References 20 publications

Control Strategies Correcting Inaccurately Programmed Fingertip Forces: Model Predictions Derived From Human Behavior

Control Strategies Correcting Inaccurately Programmed Fingertip Forces: Model Predictions Derived From Human Behavior

Radiation of phasic stretch reflex in biceps brachii to muscles of the arm in man and its restriction during development.

Spatial localization of touch in the first year of life: Early influence of a visual spatial code and the development of remapping across changes in limb position.

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