Beate Hermelin

Functional asymmetry in the reading of Braille

Abstract Difference between right and left handed reading was investigated in two experiments. In the first, summarised previously, children were found to be faster and more accurate when reading with fingers of the left than the right hand. In the second study, using adults, no difference in speed was found, but fewer mistakes were made when reading with the left than with the right middle finger. The findings are discussed in relation to training effects and cortical asymmetry.

SPATIAL CODING IN NORMAL, AUTISTIC AND BLIND CHILDREN

The experiment tested whether tactile stimulation would be coded in terms of visual location, even when no visual cues were available. 10 blind, 10 blindfolded, and 10 sighted normal as well as 10 sighted autistic children, were tested, and the results did not indicate that space is represented solely in visual terms. The findings suggested that all groups used such information as was most readily available from the incoming sensory data rather than internally represented schemata of visually organized space.

Effects of variation in the warning signal on reaction times of severe subnormals

Reaction times of normal and subnormal subjects were compared, when a warning stimulus varied in modality as well as in its temporal relation to the RT signal. When the warning stimulus was in a different modality from the RT signal, reaction times were shorter than when both were in the same modality. Mongols, in contrast to the other subjects, responded relatively faster to light than to sound. The effect of varying the time interval between warning and signal was linearly related to response speed. The results are discussed in respect to the comparative alerting effects of temporal relations between stimuli and their different modalities.

Crossmodal transfer in normal, subnormal and autistic children

Abstract Crossmodal transfer between touch and vision and vision and touch was investigated in normal, severely subnormal and autistic children. No significant facilitation was found when visual tasks were preceded by tactual ones. Crossmodality transfer was, however, significant for all groups from vision to touch. As the groups differed in verbal ability but not in their capacity to transfer from one modality to another, a hypothesis attributing such crossmodal effects to verbal coding must be rejected. In view of the results it also seems that crossmodal transfer of this kind between vision and touch may not depend on intact cortical structure.

Input restriction and immediate memory decay in normal and subnormal children.

Twelve imbeciles and 12 normals, matched for their digit memory span, were presented with three digit numbers successively and simultaneously. Seven speeds of presentation were used. Each simultaneous speed of presentation had a corresponding successive speed. Subjects were required to recall digits on the conclusion of presentation of each number. Each performance was scored as the number of errors for each digit. With simultaneous presentations the difference between the groups was significant only at fast presentation speed, where the normals were significantly better than the imbeciles. Imbeciles improved at slow speeds and became as good as normals. In the case of successive presentations differences between groups occur only in relation to the second digit, which the normals remember better than the subnormals. Both groups remember the first digit worst as rates of presentation become progressively slower. Results are explained in terms of input restriction and of memory trace decay.

like and cross modality recognition in subnormal children

The ability of mentally subnormal children to recognize previously presented visual or verbal stimuli was compared. In “like-modality” procedures they had to recognize words or pictures in the modality in which they had originally been presented. In “cross-modality” procedures the stimulus they had to recognize was in the opposite modality from that which had been used for the first presentation. In every recognition test the items had to be recognized from among an equal number of novel stimuli. Cross-modality procedures resulted in higher recognition scores. The hypothesis is advanced that this could be accounted for by the necessary translation from one type of sensory image to another in the cross-modality trials, which might minimize over-generalization.

Like and cross modality responses in normal and subnormal children

Experiments which investigated response behaviour in imbeciles and normals, in a conflict situation between a general verbal instruction and direct stimuli, were carried out. It was found that combined verbal-motor responses did not give better results than either verbal or motor responses alone. Results in accordance with the general instruction were significantly better if the subnormal children responded in a different modality from the one in which the signals were given. While normals and imbeciles differed markedly in their ability to perform the tasks in like-modality trials, this difference was less apparent in cross modality responses.