As yet, nearly all studies in face and facial affect recognition typically provide only data on the accuracy of processing, invariably also in the absence of reference data on abstract information processing. In this study, accuracy and speed of abstract visuo-spatial processing, face recognition, and facial emotion recognition were investigated in normal school children (7-10 years) and adults (25+/-4 years). In the age range of 7-10 years, accuracy of facial processing hardly increased, while speed did substantially increase with age. Adults, however, were substantially more accurate and faster than children. Differences between facial and abstract information processing were related to type of processing strategy, that is, configural or holistic processing versus featural or piecemeal processing. Improvement in task performance with age is discussed in terms of an enhanced efficiency of the configural organization of facial knowledge (facial information processing tasks), together with a further increase in processing capacity (all tasks). The differential developmental course of speed and accuracy levels indicates that speed is a more sensitive measure when children get older. Moreover, it also suggests that speed of performance, in addition to accuracy, might be successfully used in the assessment of clinical deficits, as has recently been demonstrated in children with autistic disorders of social contact.

To create a short screening instrument to investigate the development of ideomotor praxis representation (IPR), 357 normally developing children between the ages of 21/2 and 91/2 years were investigated. The IPR screening consisted of six mimed actions which had to be performed on verbal request. The greatest change in the representational style is the transition from performing the action using the body as the object to performing with an imaginary object (i.e. symbolic representation). This transition suggests a development from a concrete and egocentric level of performance to an abstract and allocentric level. Before the age of 6 years differences are evident between self‐directed and externally directed gestures. The level of symbolic representation has to be dissociated from the degree of motor precision, which shows hardly any improvement after 6 years of age. With the proposed model one may interpret the level of IPR in clinical practice. IPR screening is clinically relevant from the age of 41/2 years onwards.

The intimate relation between the sensory and motor functions of the hands during object manipulation and exploratory touch, the well-known improvement in object handling and constructive performance in ontogenesis and the emergent laterality thereof, assume changes in morphognostic capabilities in children. In this study we tried to corroborate the hypothesis of Mesker that mature and lateralized finger-thumb opposition is preceded by a stage of two-sided manual form agnosia in preschool children, followed by acquisition of morphognosis of the fingers and, finally, the thumbs. This study examined the development of gnostic hand function in 290 children from 3 to 11 years of age who drew the outlines of a meaningless wooden object passively felt with each hand without visual control. Analysis showed a clear ontogenetic change across the two age groups of increasing morphognostic function: 48% of the 6-yr.-olds drew correctly what the fingers of both left and right hands had perceived (thumbs, 14%). Of the 11-yr.-olds 91% and 61% performed perfectly with the right and left hands, respectively. The fingers preceded the thumbs in reproduction by most children, and the correct reproduction by the left thumb precedes that of the right thumb. The ontogenesis of bimanual sensorimotor functioning is discussed in the light of cortical and callosal development.

Computerised analysis of finger tapping was performed in 233 normal 5- to 12-year-old children whose hand preference was assessed with six demonstration actions. Performance with both hands became more rapid with age when tapping unimanually or simultaneously in phase with two hands as quickly as possible. There were no differences between the sexes. Performance with both hands also acquired more tapping regularity with age during unimanual tapping, whereas only the left hand did so during bimanual tapping. There was no age effect on the dexterity (speed) difference between unimanually tapping hands, nor on the relative time lag and the degree of synchrony between the hands in bimanual tapping. The degree of synchrony, however, becomes more stable in older children. The more righthanded children are, the faster the right hand is in unimanual tapping, and the more the right hand is ahead of the left hand during bimanual tapping. However, there is a right shift for both of these variables which makes them poor predictors of hand preference. These results suggest that there is a strong bias towards the right hand in complete righthanders as well as--to a lesser extent--in all others, which might be connected to the leading role of the left hemisphere for the performance aspects of hand motor function under study.

To create a short screening instrument to investigate the development of ideomotor praxis representation (IPR), 357 normally developing children between the ages of 2 1/2 and 9 1/2 years were investigated. The IPR screening consisted of six mimed actions which had to be performed on verbal request. The greatest change in the representational style is the transition from performing the action using the body as the object to performing with an imaginary object (i.e. symbolic representation). This transition suggests a development from a concrete and egocentric level of performance to an abstract and allocentric level. Before the age of 6 years differences are evident between self-directed and externally directed gestures. The level of symbolic representation has to be dissociated from the degree of motor precision, which shows hardly any improvement after 6 years of age. With the proposed model one may interpret the level of IPR in clinical practice. IPR screening is clinically relevant from the age of 4 1/2 years onwards.