Neuropsychological presentation and adaptive skills in high-functioning adolescents with visual impairment: A preliminary investigation.

Studies in infants and young children with congenital visual impairment (VI) have indicated early developmental vulnerabilities, conversely research with older children and adults have highlighted areas of cognitive strength. A minimal amount is known, however, about the possible combination of strengths and weaknesses in adolescence, and this present study therefore aims to explore the neuropsychological presentation and adaptive behavior profile in high-functioning adolescents with congenital VI. Participants completed a battery of commonly used neuropsychological measures assessing memory, executive function, and attention. The measures utilized focused on auditory neuropsychological function, because only subtests that could be completed with auditory administration were suitable for this sample. Parents completed standardized measures of adaptive behavior, executive function, and social communication. Compared to aged-based norms for normal sight, adolescents with VI demonstrated strengths in aspects of working memory and verbal memory. Furthermore, performance across the neuropsychological battery was within or above the average range for the majority of the sample. In contrast, parent-report measures indicated areas of weakness in adaptive functioning, social communication, and behavioral executive functioning. Overall, this study provides preliminary evidence that relative to fully sighted peers, high-functioning adolescents with VI present with an uneven profile of cognitive and adaptive skills, which has important implications for assessment and intervention.

Graphic displays: the effects of orientation on the tangible perception of histograms and pie charts.

Two studies designed to investigate the ability of blind subjects to interpret tangible graphic displays of data at varying degrees of orientation are reported. In the first experiment visually handicapped children were required to interpret histograms and pie charts presented at two different orientations. Horizontally oriented histograms were found to have a significant advantage over vertically oriented histograms, but there was no effect of orientation on pie charts. In the second study horizontally and vertically oriented histograms were again compared using a subject sample comprised only of congenitally or very early blind children. The results confirmed the superiority of horizontally presented histograms over the more common vertical display.

When did Mrs Thatcher resign? The effects of ageing on the dating of public events.

Two experiments investigated whether, in light of the commonly reported phenomenon of subjective time acceleration with age, there would be an effect of age on the dating of public events. In the first experiment covering the past seven years there was the suggestion of a decrease in forward telescoping with age, and in the second covering the period from 1977-89 this trend was continued, with the over-60s group now showing a tendency to date events too distantly. This effect is uncommon in dating studies and may offer evidence for the existence of time acceleration. An additional finding was that adults in the age range 35-50 years showed greater accuracy in dating events than did university students and adults over the age of 60.

A visually impaired savant artist: interacting perceptual and memory representations.

In this single case study, paintings by a visually impaired and cognitively handicapped savant artist are evaluated. He paints his pictures exclusively from memory, either after having looked at a natural scene through binoculars, or after studying landscape photographs in brochures, catalogues, and books. The paintings are compared with the models from which they were derived, and the resulting generative changes are accounted for by an interaction between impaired visual input and memory transformations.

A date to remember: the nature of memory in savant calendrical calculators.

BACKGROUND: Savant calendar calculators can supply with speed the day of the week of a given date. Although memory is suggested to be an important component of this unusual ability, memory function has never been systematically investigated in these skilled yet learning impaired individuals. METHODS: Eight savant calendrical calculators, most of whom had autism, were compared with eight verbal IQ, age and diagnosis matched controls on digit and word span tests and measures of long-term memory for words and calendrical information (individual years). In an analogue to the 'generation effect', the savants' memory for dates was also compared following calculation and study/read tasks. RESULTS: The savants did not differ from controls on measures of general short- and long-term memory. They did, however, show a clear recall superiority for the long-term retention of calendrical material. They also remembered calculated dates better than those that were only studied. CONCLUSIONS: A general mnemonic advantage cannot explain savant date calculation skills. Rather, through exposure to date information, the savants are suggested to develop a structured calendar-related knowledge base with the process of calculation utilizing the interrelations within this knowledge store. The cognitive processing style characteristic of autism may also play a role in the acquisition of this savant ability.

Can children with autistic spectrum disorders perceive affect in music? An experimental investigation.

BACKGROUND: Children with autistic spectrum disorders typically show impairments in processing affective information within social and interpersonal domains. It has yet to be established whether such difficulties persist in the area of music; a domain which is characteristically rich in emotional content. METHODS: Fourteen children with autism and Asperger syndrome and their age and intelligence matched controls were tested for their ability to identify the affective connotations of melodies in the major or minor musical mode. They were required to match musical fragments with schematic representations of happy and sad faces. RESULTS: The groups did not differ in their ability to ascribe the musical examples to the two affective categories. CONCLUSIONS: In contrast to their performance within social and interpersonal domains, children with autistic disorders showed no deficits in processing affect in musical stimuli.

The pictorial context dependency of savant artists: a research note.

The relative immunity of the concept of size constancy in the face of changes to the retinal image as well as the pictorial device of linear perspective were investigated with 9 savant artists and 9 controls. For drawing use of pictorial rules seemed independent of levels of intelligence; however, when a construction instead of a drawing task had to be carried out, diagnosis rather than the presence or absence of talent was the decisive factor.

A savant poet.

Poems by an individual with a diagnosis of Asperger's Syndrome were analysed and compared with those of a comparison poet. Though the savant poet performed less efficiently on formal language tests supposed to tap creativity, there were few differences between the two poets in regard to the poems' content and the use of various structural devices. The poems by the savant referred more often to aspects of self-analysis, while descriptions of people not related to the self were less frequent. Both poets made use of similes and metaphors. The results are discussed in terms of different modular domains within the language system.

Savants, segments, art and autism.

This study describes two experiments which investigate pattern construction by graphically gifted, autistic savants. We explore whether the notion of weak central coherence in autism might be extended to account for the relatively high frequency of savants among the autistic population. We also suggest that an awareness of constituent segments in wholes may be relevant to artistic talent in general.

The effects of data-driven and conceptually driven generation of study items on direct and indirect measures of memory.

Two experiments are reported which investigated the effects of data-driven generation of study items on direct and indirect measures of memory. Previous research in the field of implicit memory has traditionally employed generation procedures at encoding which focused on conceptually driven processing. The present study undertook to device data-driven generation procedures that were predicted to lead to a generation effect on word-stem completion. In Experiment 1 subjects had to generate target items from anagrams and newly developed "assemblograms", requiring mainly data-driven processing, as well as from semantic cues and definitions, involving mainly conceptually driven processing. Effects of these generate conditions were compared to the usual name condition on a direct word-stem cued recall test, and on an indirect word-stem completion test. Differences between data-driven generation on the stem completion task and the name condition failed to reach significant differences in retention. In Experiment 2 subjects generated targets from assemblograms and from semantic cues. The data revealed the predicted occurrence of a generation effect on an indirect memory test following data-driven generation. The finding of a generation effect in an indirect as opposed to a direct memory test was seen as support for the view that generating a study item may enhance data-driven as well as conceptually driven processing, depending on the processing demands made by generation procedures. The results were interpreted within the transfer-appropriate processing framework, with additional reference to Glisky and Rabinowitz's two-component account of generation effects (Glisky & Rabinowitz, 1985).

Visual and motor functions in graphically gifted savants.

Savant artists represent a conundrum to our understanding of the nature of high level specific talents as well as to the concept of general intellectual impairment. In the present paper, we are particularly concerned with the relationship between general perceptual-motor functions in relation to drawing aptitude. Drawing is by definition a perceptual-motor operation, yet mental handicap tends to be associated with some degree of impairment in this area. The following study seeks to isolate such aspects of performance on general perceptual-motor skills that might be associated with drawing ability, and may thus be regarded as building blocks underlying the manifestation of graphic talent. The results are discussed in terms of the relationships between graphic talent, non-verbal intelligence and visual-motor functions.

Degree of accuracy in perceiving graphic and representational information through touch.

Two studies are reported in which comprehension and interpretation of raised-line images and graphs by touch were investigated. Experiment 1 required blind-folded sighted subjects and blind subjects to rate the veracity of raised-line drawings in conveying the nature of an image when the complexity of the depicted object was manipulated (from simple outlines to more complex exaggeration of salient features). Results showed no effect of complexity on veracity ratings. Experiment 2 involved the assessment of blind and visually impaired subjects of line-graphs, histograms and pie charts which varied in information content and perceptible detail (textured and untextured). Histograms were easier to interpret than line-graphs, but there were no differences between histograms and pie charts. An increase in information content had little effect on comprehension.

Bottle, tulip and wineglass: semantic and structural picture processing by savant artists.

Semantic and structural aspects of picture processing were investigated with graphically gifted mentally handicapped subjects and intellectually normal children. The results suggest that savants as well as controls rely primarily on semantically organised memory schemata when reproducing pictures. A semantically determined strategy also determines picture sorting. The findings indicate that within the domain of expertise there appears to be no difference between savants and normals regarding the nature of the mental structures underlying specific talents. The mental structures on which such talents are based, should therefore be regarded as being relatively independent of the level of general cognitive functioning.

Reading strategies in partially sighted children.

We know very little about the reading strategies adopted by children with poor vision. Here a group of children with a range of visuo-perceptual problems including defective foveal vision and impaired eye-movements are compared to a group of fully sighted children (matched on age and verbal ability). Three studies using lexical decision tasks with words (regular and irregular) and non-words (legal, illegal and pseudohomophones) as well as with format distorted items, are reported. Regularity effects, as well as effects of intact and disrupted spelling units emerged but the predominant finding was that the partially sighted children though making good use of the 'visual' route in word recognition also relied on phonological mediation. The conclusions drawn were that the phonological emphasis in teaching partially sighted children was a very effective method for compensating for poor vision, and the problems of a visuo-perceptual nature did not seem connected to the development of dyslexia.

Getting in touch with pictures and words: educational strategies for the blind.

Tactual processing of information is of much more significance for blind than sighted persons, for whom it is a less dominant channel of communication. However, it has received much less attention than verbal or visual processing of information. In this article, the main outcomes of a series of experiments with congenitally blind children are described, with their performance on a series of spatial reasoning and shape recognition tasks compared to that of blindfolded, partially sighted controls. Results suggest that congenitally blind subjects perform as well as, if not better than, blindfolded subjects on simple 2-dimensional tactual processing tasks, but less well on more complex tasks requiring them to store, compare and label objects. This is thought to reflect their poorer sensory coding abilities and their more limited experience of pictures and representations of objects. While other work suggests that blind children can be trained to enhance these skills, the fact that they appear to utilise different learning strategies should be taken into consideration in educational practice and explored further in future research.

The 'reverse-generation' effect: a comparison of memory performance between blind and sighted children.

Three studies are reported which investigate word priming and memory in congenitally blind and sighted children. Two conditions were of particular interest, a neutral condition, where children read aloud or repeated a word, and a generate condition, where children supplied a target word to a close semantic associate given as a cue. Later, memory for those items was tested and although the two groups did not differ in overall performance a marked interaction across group and condition was noted. The sighted children showed a significant 'generation' effect (Slamecka & Graf, 1978), where active involvement in a word task led to increased memory. In contrast, the congenitally blind remembered relatively less material when active participation was required, showing a 'reverse-generation' effect. The results are discussed with reference to the effect on memory of data and conceptually driven processing in the study phase. It is tentatively suggested that the congenitally blind may show different learning strategies from the sighted as a result of allocating more attention to sensory information processing.

A comparison of the word recognition processes of blind and sighted children.

2 word/nonword decision experiments were carried out to investigate differences in reading that might exist between congenitally blind children reading Braille and sighted children dealing with print. 3 aspects of single-word recognition were studied: semantic processing, word-frequency effects, and phonological recoding. In addition, a comparison of word recognition performance was made under normal conditions and under conditions of reduced legibility. The sighted children showed an increased semantic facilitation effect with degraded when compared with undegraded print conditions. In contrast, for the blind children this trend was reversed. The magnitude of the word-frequency effect was unaffected by script legibility in either group. In addition, an increased difficulty of rejecting pseudohomophones (e.g., bloo) relative to legal nonwords (e.g., ploo) was found for the blind in the degraded condition and for the sighted with degraded and undegraded print. These results are discussed in terms of the relative influence of perceptual feature-analysis processes and attentional semantic processing.

Phonological and tactual coding of Braille by blind children.

Two experiments were carried out to investigate phonological and tactual coding in Braille reading by blind children. In the first, the children read aloud two lists of word pairs, one item at a time. The second or 'target' word of each pair (e.g. on) was the same in both lists. In one list, the congruent list, the phonology and orthography of the first word of the pair (sun) provided no inconsistency with respect to the target word (sun-on). In the other incongruent list, the preceding word was similar in orthography but inconsistent in phonology with respect to the target word (son-on). The children named the target words (i.e. on) significantly faster in the context of the congruous list than in the context of the incongruous list, thus revealing a phonological effect in the blind children's reading of single words. In addition, direct lexical access, from tactual input, seems to proceed with the same facility for the blind as does visual input for the sighted. In the second study the children read aloud words which were either orthographically regular or irregular. The results indicated that the irregular words took longer to name than the regular words. It was suggested that blind children, like sighted children, show phonological interference effects in word naming. The results are discussed in relation to recent models of the processes involved in word naming.