Miriam Ittyerah

Hand preferences and hand ability in congenitally blind children

Congenitally blind and sighted blindfolded children between the ages of 6 and 14 years were tested for hand preference with performance tasks. There were no differences between the groups in direction or degree of hand preference. The degree of handedness increased with age and was essentially linear though the blind seemed to be somewhat less lateralized at the younger ages. When the same groups were required to match three-dimensional bricks for height, depth, breadth, and volume, no hand advantages were found for either group. Both groups of children improved in their accuracy of spatial discriminations with age. Further, the degree of lateralization on the handedness task did not relate to ability on the tactile task or to differences between the right and left hands on the tactile task. Thus, there is no effect of blindness on tactile matching ability nor is there an effect of the hand used in the task.

The Actual and Ideal Self-concept in Disabled Children, Adolescents and Adults

The actual and ideal self-concepts of handicapped children, adolescents and adults were studied with the help of questionnaires to compare their responses to body image, skills/abilities, life experience, and social interaction. Results indicated that children had a more positive self-concept than adults and adolescents. Men had a more positive self-concept than females. Further, social interaction and abilities were rated more positively than body image and life experience. Correlations between the actual and ideal selves revealed a positive relation between the actual self and the desired ideal self for all the groups and there were no gender differences. Narrative analysis of the groups revealed that adults held a more positive view of life as compared to adolescents or children. The positive views of the self were a consequence of factors that are largely internal to the respondent, such as the use of mature ways of thinking and maintaining ones self-respect. The negative views of the self were rooted in external factors over which the individual had little or no control such as poverty and negative attitudes of others. Although the female disabled group had a lower selfconcept than males, there was a positive relationship between their actual and ideal selves indicating acceptance of their congenital defects as a challenge to integrate into the mainstream.

Remembering Object Position in the Absence of Vision: Egocentric, Allocentric, and Egocentric Decentred Frames of Reference

In three experiments we examined whether memory for object locations in the peripersonal space in the absence of vision is affected by the correspondence between encoding and test either of the body position or of the reference point. In particular, the study focuses on the distinction between different spatial representations, by using a paradigm in which participants are asked to relocate objects explored haptically. Three frames of reference were systematically compared. In experiment 1, participants relocated the objects either from the same position of learning by taking as reference their own body (centred egocentric condition) or from a 90° decentred position (allocentric condition). Performance was measured in terms of linear distance errors and angular distance errors. Results revealed that the allocentric condition was more difficult than the centred egocentric condition. In experiment 2, participants performed either the centred egocentric condition or a decentred egocentric condition, in which the body position during the test was the same as at encoding (egocentric) but the frame of reference was based on a point decentred by 90°. The decentred egocentric condition was found to be more difficult than the centred egocentric condition. Finally, in experiment 3, participants performed in the decentred egocentric condition or the allocentric condition. Here, the allocentric condition was found to be more difficult than the decentred egocentric condition. Taken together, the results suggest that also in the peripersonal space and in the absence of vision different frames of reference can be distinguished. In particular, the decentred egocentric condition involves a frame of reference which seems to be neither allocentric nor totally egocentric.

Hand skill and hand preference in blind and sighted children.

Congenitally blind and sighted blindfold children between the ages of 6 and 15 years were compared with each other for hand preferences and hand ability. All the children performed a 20-item hand preference test and every child performed three hand ability tasks: a sorting task, a finger dexterity task, and the Minnesota rate of manipulation task, each separately with the left and the right hand. Results indicated no differences between the hand preferences of the two groups. The sighted children were faster than the blind children on some of the hand ability tasks. There were no differences between the left and right hands for any of the tasks for either group. Results indicate an equipotentiality between the hands and suggest the possibility of training both hands during development on tasks that require tactile ability.

Movement Imagery in Young and Congenitally Blind Children: Mental Practice without Visuo-spatial Information.

The study explored whether young children and congenitally totally blind children show mental practice effects for blind movements which cross the body midline. Experiment 1 tested blindfolded sighted children, with a mean age of 7 years and 11 months, on recall of a linear movement. Prior to recall, subjects either had to perform, or to imagine irrelevant (larger/smaller/same) movements. Irrelevant movements produced significant bias (CE/Constant Errors), whether carried out or imaged, although bias from imagined movements was smaller. The VE (variance/consistency) scores improved with (actual and mental) rehearsal. Articulatory suppression during delays had no effect. Experiment 2 used the same paradigm to test three groups of congenitally totally blind children with respective mean Mental Ages (MA) of 10 years and 7 months, 13 years and 7 months, and 16 years and 4 months, based on IO scores on the Williams Intelligence Test (1956) for visually handicapped children. Irrelevant movements during delays produced bias (CE) in recall, whether the movements were carried out or imagined, although bias was smaller in imagery conditions. The (CE) bias effects did not interact with MA. Mental Age interacted significantly with Delay Tasks in VE scores. The lowest MA group was less efficient (more variable) than the others, particularly in (actual and imagined) rehearsal. Articulatory suppression had no effect. The results suggest that young children can show mental practice effects in the absence of current visual cues, and that visuospatial imagery is not a necessary condition, because imagined movements also biased recall by the congenitally totally blind. It was argued that movement as well as cognitive factors can be involved in mental practice effects, and that the nature of mediation depends on the available information.

Memory for curvature of objects: haptic touch vs. vision.

The present study examined the role of vision and haptics in memory for stimulus objects that vary along the dimension of curvature. Experiment 1 measured haptic-haptic (T-T) and haptic-visual (T-V) discrimination of curvature in a short-term memory paradigm, using 30-second retention intervals containing five different interpolated tasks. Results showed poorest performance when the interpolated tasks required spatial processing or movement, thereby suggesting that haptic information about shape is encoded in a spatial-motor representation. Experiment 2 compared visual-visual (V-V) and visual-haptic (V-T) short-term memory, again using 30-second delay intervals. The results of the ANOVA failed to show a significant effect of intervening activity. Intra-modal visual performance and cross-modal performance were similar. Comparing the four modality conditions (inter-modal V-T, T-V; intra-modal V-V, T-T, by combining the data of Experiments 1 and 2), in a global analysis, showed a reliable interaction between intervening activity and experiment (modality). Although there appears to be a general tendency for spatial and movement activities to exert the most deleterious effects overall, the patterns are not identical when the initial stimulus is encoded haptically (Experiment 1) and visually (Experiment 2).

Moral Development and its Relation to Perspective Taking Ability

An attempt was made to study the relationships between moral development and perspective taking abilities of children at three age levels (i.e., 5-6 years, 8-9 years and 11-12 years). The results indicated that both moral reasoning and perspective taking improved with age. Gender differences were significant for only the cognitive perspec tive taking ability suggesting that girls possess more prosocial characteristics. Multiple correlations indicated that perspective taking abilities have a significant effect on moral reasoning for only the youngest age group. This suggests that perspective taking ability is a crucial mediator for moral development at the initial stages. Hence, perspective taking once acquired increases only slightly to include the areas of perception or cognition, whereas moral reasoning is acquired through slow and successive comprehension of the various moral issues confronted in the course of development.

FANTASY AND REALITY DISTINCTION OF CONGENITALLY BLIND CHILDREN

40 congenitally blind and 40 sighted children were tested for fantasy-reality distinctions of real and imagined objects and the development of concepts of darkness, hidden objects, space, dreams, emotions, facial expressions, size, and height. Analysis indicated that the blind children distinguished between contents of fantasy and reality, although they were less sure about the reality status of the objects. The sighted group gave more reality responses than the blind group for the concepts of dreams and hidden objects, but the remaining concepts were somewhat the same. Cognitive development explained in terms of theory formation may not explain the development of young blind children completely. Their knowledge that contents of fantasy are not real may be obtained through interpersonal experiences that are publicly shared.

Inter- and Intra-Modal Processing of Sensory-Specific Stimuli

Inter- and intra-modal processing was compared with modality-specific forms in two experiments on a group of 40 university students. In Exp. I, the RTs for tactual-to-visual and visual-to-visual processing were compared for 20 subjects, and in Exp. II, the visual-to-tactual and the tactual-to-tactual processing were compared for another group of 20 subjects. Analysis showed that intra-modal processing is faster than inter-modal processing. Further, the “same” RT is faster than the “different” RT. The inter- and intra-modal processing differences are based on the delay in retrieval and recognition across sensory-specific areas.

Verbal Abuse and Cognition in the Developing Mind

This study compared a group of 90 high verbally abused and 90 low verbally abused children on tests of cognitive development. The Cognitive Assessment System made up of attention, coding (simultaneous processing and successive processing), and planning subtests were administered to the high-abused and low-abused children. Results indicate that the high-abused children scored lower than the low-abused children on all the tests. In attention and simultaneous processing tasks, the younger children in the high-abused group performed better than the older children, suggesting better attention strategies and an absence of negative thought in the younger groups of high-abused children. Girls performed better than boys on the attention task. Results suggest that verbal abuse is associated with less favorable neuropsychological functioning.