Search results for "motor program"
showing 10 items of 12 documents
The Early Indicators of Functional Decrease in Mild Cognitive Impairment
2016
OBJECTIVES: Motor deficiency is associated with cognitive frailty in patients with Mild Cognitive Impairments (MCI). In this study we aimed to test the integrity of the muscle synergy involved in an arm-pointing movement in MCI patients, non-impaired functionally. Thus, we were able to test the hypothesis that early motor indicators exist in this population at a preclinical level. METHODS: The electromyographic signals were collected for 11 muscles in 3 groups: Young Adults (YA), Aged Adults (AA), and MCI patients. The AA and MCI groups presented the same functional status. Each subject performed twenty arm-pointing movements from a standing position. RESULTS: The main differences were (1) …
Influence of automatic word reading on motor control.
1998
We investigated the possible influence of automatic word reading on processes of visuo-motor transformation. Six subjects were required to reach and grasp a rod on whose visible face the word 'long' or 'short' was printed. Word reading was not explicitly required. In order to induce subjects to visually analyse the object trial by trial, object position and size were randomly varied during the experimental session. The kinematics of the reaching component was affected by word presentation. Peak acceleration, peak velocity, and peak deceleration of arm were higher for the word 'long' with respect to the word 'short'. That is, during the initial movement phase subjects automatically associate…
Preparedness for landing after a self-initiated fall.
2012
A startling auditory stimulus (SAS) causes a faster execution of voluntary actions when applied together with the imperative signal in reaction time tasks (the StartReact effect). However, speeding up reaction time may not be the best strategy in all tasks. After a self-initiated fall, the program for landing has to be time-locked to foot contact to avoid damage, and therefore advanced execution of the program would not be convenient. We examined the effects of SAS on the landing motor program in 8 healthy subjects that were requested to let themselves fall from platforms either 50 or 80 cm high at the perception of a visual imperative signal and land on specific targets. In trials at rand…
Excitability of subcortical motor circuits in Go/noGo and forced choice reaction time tasks
2006
The size of the response to a startling auditory stimulus (SAS) may reflect the excitability of the reticulospinal tract. In this study, we examined whether there was any excitability change in the reticulospinal tract during preparation for execution of two types of choice reaction time task: a forced choice reaction time task (fCRT) and a Go/no-Go task (GnG). In 13 healthy volunteers we used three types of trials: control trials in which subjects were requested to perform ballistic wrist movements during fCRT or GnG tasks; test trials in which a SAS was presented with the visual cue, and baseline trials in which SAS was presented alone. Latency and area of the responses to SAS were measur…
Speeding up gait initiation and gait-pattern with a startling stimulus.
2008
Human gait involves a repetitive leg motor pattern that emerges after gait initiation. While the automatic maintenance of the gait-pattern may be under the control of subcortical motor centres, gait initiation requires the voluntary launching of a different motor program. In this study, we sought to examine how the two motor programmes respond to an experimental manipulation of the timing of gait initiation. Subjects were instructed to start walking as soon as possible at the perception of an imperative signal (IS) that, in some interspersed trials was accompanied by a startling auditory stimulus (SAS). This method is known to shorten the latency for execution of the motor task under prepar…
Deafferentation and pointing with visual double-step perturbations
1999
The capability of reprogramming movement responses following changes in the visual goal has been studied through the double-step paradigm. These studies have shown that: (a) continuous internal feedback-loops correct unconsciously the dynamic errors throughout the movement; (b) proprioceptive information and/or the efference copy have a privileged status among central processes, insuring on-line regulation of the initial motor commands; and (c) generation of the motor program starts after target presentation, and is continuously updated in the direction of the current internal representation of the target, at least until the onset of hand movement. This main corrective process of the initia…
Effects of a ludic-motor program on motor development and early literacy skills in preschool children
2017
There is insufficient evidence in the literature about many correlations between motor and cognitive skills in 3-5 year old children [1]. The aim of this study was to explore the relationship between the development of the gross motor skills and the prerequisites of reading/writing following a ludic-motor program (LMP) in pre-school children. This study has involved 189 children (age: 4.62 ± 0.97 years; height: 107.83 ± 7.82 cm, body weight: 19.84 ± 4.95 kg) attending 8 kindergartens in Palermo. The children were randomly divided in a control group (C, n= 29), a 1-intervention group (I-1, n= 120) and a 2-intervention group (I-2, n= 40). I-1 and I-2 respectively performed 4 and 10 hours/week…
Dynamics-based action recognition for motor intention prediction
2020
Abstract Powered lower-limb prostheses presented in the previous chapter require a natural and easy-to-use interface for communicating amputee’s motor intention in order to select the appropriate motor program in a given context or simply to commute from an active (powered) to a passive mode of functioning. To be accepted by amputees, such an interface should (1) not put additional cognitive load on the end-user, (2) be reliable and (3) be minimally invasive. In this chapter we present one possible solution for achieving that goal: a robust method for autonomously detecting and recognizing motor intents from a wearable sensor network mounted on a sound leg. The sensor network provides a rea…
Recognising a hand by grasp.
2000
The present study aimed to demonstrate that motor representations are used to recognise biological stimuli. In three experiments subjects were required to judge laterality of hands and forearms presented by pictures. The postures of the hands were those assumed when holding a small, medium and large sphere. In experiment 1, the sphere held in hand was presented, whereas in experiment 2 it was absent. In experiment 3, the same images, showing holding-a-sphere hands, as in experiment 1 were presented, but without forearm. In all experiments one finger of each hand could be absent. In experiment 1 recognition time was longer for those hand postures for which the corresponding grasping motor ac…
Quantitative assessment of stereotyped and challenged locomotion after lesion of the striatum: a 3D kinematic study in rats.
2009
Background Although the striatum is in position to regulate motor function, the role of the structure in locomotor behaviour is poorly understood. Therefore, a detailed analysis of locomotion- and obstacle avoidance-related parameters was performed after unilateral lesion of the striatum in rats. Methods and Results Using the three dimensional motion capture technology, kinematics of walking and clearing obstacles, head and body orientation were analyzed before and up to 60 days after the lesion. Recordings were performed in treadmill running rats with or without obstacles attached to the treadmill belt. The lesion, which was induced by the direct injection of the mitochondrial toxin malona…