Biomedical subjects

M M Sepehr

Publications and source records attributed to M M Sepehr.

3 recordsLinked to original sources

PubMed1988

The relationship between metaphoric and crossmodal abilities during development.

Metaphoric and crossmodal abilities were investigated in children, aged 3-8 years. For this study metaphoric performance was regarded as based on the production of a relationship between physically dissimilar stimuli (presented in two sense-modalities), which are not normally perceived as being related. It was asked at what age crossmodal performance, based on specific rather than global/categorical differences within stimulus pairs, can be regarded as distinct from metaphoric performance. In Expt. 1, metaphoric and crossmodal two-trial "recognition" tasks were given in Touch and Vision at all ages. In Expt. 2,3- and 4-year-olds were first trained over 6-20 trials to choose one of two stimuli in one modality (Touch or Vision) and then given one "recognition" trial in the alternate modality. Children as young as three could relate specific physical stimulus differences across sense-modalities. Although metaphoric recognition was present on two problems in children aged 3 and 4 years, metaphoric performance was inferior to crossmodal performance at all ages. Crossmodal abilities improved with age due to improved intramodal skills; such intramodal improvement can probably account for only a part of the improvement on the metaphoric task. Reasons are given why metaphoric and crossmodal abilities may be separate over the age range 3-8 years.

Child↗

PubMed1987

Differential accuracy of aimed movements to visual and somatic targets in young children.

Children, aged 2.5-8 years, were required to touch accurately a target located either on their bodies or on the chair in which they sat. Movements were made when visual information was: 1. complete (target lit for 3 s, room illuminated); 2. partial (target lit for 3 s, room dark); 3. reduced (target lit for 0.7 s, room dark); and finally, when the target was somatically specified. Movements to visible targets did not differ in any important way as a function of target location with respect to on/off body. Accuracy improved with age to visually but noto somatically specified targets, decreased with decreasing availability of visual information, and was poorest to somatically specified targets. We conclude that during development, the sense-modality through which the target is specified and the visibility of the arm/hand during the movement, but not the personal/extra personal visible space in which the target is located, are important determinants of reaching performance.

Child↗

PubMed1986

The accuracy of aimed movements to visual targets during development: the role of visual information.

Children aged 1.5 to 8 years were required to touch accurately an illuminated target lamp located on a vertical board. Movements were made when visual information was complete (target lit for 3 s, room illuminated; partial (target lit for 3 s, room dark, and reduced (target lit for 0.7 s, room dark). Dependent variables were response accuracy, reaction time, and movement time. Accuracy decreased with decreasing availability of visual information and improved with age under all conditions. Reaction times were shorter in the dark (Conditions 2 and 3) than in the light; they decreased with age up to age 5 and did not continue to decrease thereafter. Movement time did not change with age under Conditions 1 and 3 but tended to increase with age under Condition 2. Slower movements were more accurate at all ages, provided visual feedback could be utilized. Increased reliance on the strategy "slower movements yield higher accuracy" was held to account for developmental changes under Condition 2, whereas in Conditions 1 and 3 improvement in the efficiency of motor preprogramming was implicated.

Age Factors↗