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Biomedical subjects

H Levarlet-Joye

Publications and source records attributed to H Levarlet-Joye.

6 recordsLinked to original sources
PubMed1991

Reaction times recording methods: reliability and EMG analysis of patterns of motor commands.

Different methods for estimating reaction times (RTs) from either finger flexion or finger extension responses have been evaluated. The onset of finger movement was recorded with a photoelectric method and the results are compared with RT measures based on microswitch closure or onset of electromyographic (EMG) activity in the prime move muscle. EMG analysis showed the voluntary motor commands to present a characteristic ballistic pattern in RTs. However, this was not true for a number of trials with unusually long RTs which involved ramp or double burst EMG patterns that were interpreted as reflecting errors in the force calibration of motor commands. RTs based on photoelectric recording of onset of finger extension were consistently related to the RTs estimated from EMG onset in the prime mover muscle. It is concluded that the EMG onset or the finger lift photoelectric method is best suited for reliable RT recording.

Electricity↗
PubMed1984

The relationship between reaction times and hand and foot laterality in the slightly mentally handicapped.

The study was carried out on 16 normal children and 16 slightly mentally handicapped children aged 9 years and 10 months. We studied: simple reaction time and simple and complex choice reaction time for the hand and foot. Hand and foot lateralities were determined using six tests. This study enabled us to show different elements: Hand and foot laterality is less often confirmed among the handicapped children. For both groups the fastest hand and foot simple reaction times do not indicate the preferred limb. The possibility of choice in the case of the hand considerably delays the reaction times for the handicapped children. This tendency is not confirmed in the case of choice reaction times for the foot, where the handicapped children are not significantly slower than the normal children, in a choice situation. If the choice situation becomes complicated the handicapped children are slower than the normal children. With the normal children simple reaction times are slower for the foot than for the hand. However, the handicapped children do not show a significant difference between hand and foot reaction times. We put forward the theory that this fact could be explained by the different form of the motor response. Handicapped children have greater difficulty in integrating precision and speed of movement, factors which occur in the movement of the hand reaction time but not in the movement of the foot reaction time.

Child↗
PubMed1978

The development of motor competency in normal and slightly mentally handicapped children.

A study of the motor development and the corporal schema integration was carried out on 60 normal children aged between 6 and 10, and 40 slightly mentally handicapped children of 8 and 10 years of age. The deficiency at the level of manual rapidity is the most important element concerning the motive debility of mentally handicapped children. The tests show that there is no parallelism between the motive retardedness and the level of attainment of the corporal schema. In fact, the motor debility of 8 years old children is emphasized at the age of 10 with reference to normal children. On the other hand, if, at the age of 8, the mentally handicapped children have a lag of the corporal schema acquisition, these children have nearly overcome their retardedness at the age of 10. Therefore one can conclude that the motor retardedness of the slightly mentally handicapped children is not essentially due to a deficiency of the corporal schema integration.

Achievement↗