Grace Iarocci

Deconstructing executive deficits among persons with autism: Implications for cognitive neuroscience

Individuals with autism demonstrate impairments on measures of executive function (EF) relative to typically developing comparison participants. EF is comprised of several processes including inhibition, working memory and set shifting that develop throughout the lifespan. Impairments in EF may appear early in development and persist, or may represent a more transient delay which resolves with time. Given the unevenness of the cognitive profile of persons with autism, understanding the development of EF poses methodological challenges. These issues include those related to matching measures and the choice of comparison participants to which the performance of persons with autism will be compared. In the current review, we attempt to break down the processes of inhibition, working memory and set shifting among persons with autism. We propose to do this within a developmental perspective that highlights how matching measures and comparison participants can affect the interpretation of research findings.

On Mosaics and Melting Pots: Conceptual Considerations of Comparison and Matching Strategies

Conceptual and pragmatic issues relevant to the study of persons with autism are addressed within the context of comparison groups and matching strategies. We argue that no choice of comparison group or matching strategy is perfect, but rather needs to be determined by specific research objectives and theoretical questions. Thus, strategies can differ between studies in which the goal is to delineate developmental profiles and those in which the focus is the study of a specific aspect of functioning. We promote the notion of a “mosaic,” rather than a “melting pot,” approach to science in which researchers communicate conservative and precise interpretations of empirical findings.

Intact Covert Orienting to Peripheral Cues Among Children with Autism

The focus of the present study was to examine covert orienting responses to peripheral flash cues among children with autism in a situation where attentional processes were taxed by the presence of distractors in the visual field. Fourteen children with autism (MA = 6–7 years) were compared to their MA-matched peers without autism on a forced choice RT covert orienting paradigm. The task conditions varied with regard to the target location, the validity of the cue, and the presence or absence of distractors. The results showed no group differences as both children with autism and their MA-matched peers showed similar effects of cue validity and distractors. These findings are inconsistent with the view that orienting is generally impaired in children with autism.

Visual influences on speech perception in children with autism

The bimodal perception of speech sounds was examined in children with autism as compared to mental age—matched typically developing (TD) children. A computer task was employed wherein only the mouth region of the face was displayed and children reported what they heard or saw when presented with consonant-vowel sounds in unimodal auditory condition, unimodal visual condition, and a bimodal condition. Children with autism showed less visual influence and more auditory influence on their bimodal speech perception as compared to their TD peers, largely due to significantly worse performance in the unimodal visual condition (lip reading). Children with autism may not benefit to the same extent as TD children from visual cues such as lip reading that typically support the processing of speech sounds. The disadvantage in lip reading may be detrimental when auditory input is degraded, for example in school settings, whereby speakers are communicating in frequently noisy environments.

Age Differences in Visual Search for Compound Patterns: Long- Versus Short-Range Grouping

Visual search for compound patterns was examined in observers aged 6, 8, 10, and 22 years. The main question was whether age-related improvement in search rate (response time slope over number of items) was different for patterns defined by short- versus long-range spatial relations. Perceptual access to each type of relation was varied by using elements of same contrast (easy to access) or mixed contrast (hard to access). The results showed large improvements with age in search rate for long-range targets; search rate for short-range targets was fairly constant across age. This pattern held regardless of whether perceptual access to a target was easy or hard, supporting the hypothesis that different processes are involved in perceptual grouping at these two levels. The results also point to important links between ontogenic and microgenic change in perception (H. Werner, 1948, 1957).

A developmental change in selective attention and global form perception

The primary purpose of the present study was to examine the processing of local and global perception in relation to selective attention during development from childhood to early adulthood. Filtering was the specific component of selective attention that was examined. The influence of varying distractor congruency and compatibility on relative local-global processing was also examined. Distractor congruency and compatibility did not differentially affect local and global processing. With the presence of neutral distractors, however, 6- and 8-year-old participants demonstrated a greater increase in RTs for global targets relative to local targets whereas older children and adults showed the same pattern of RTs for both local and global targets. The results are suggestive of separate developmental trajectories for global and local level processes, with global processing undergoing developmental change at least until 8 years of age.

The modulation of visual orienting reflexes across the lifespan

The development of reflexive and voluntary shifts of visual attention, as well as relations between the two forms of shifting, were examined in three groups of children (5, 7, and 9 years old), one group of young adults (24 years old), and two groups of senior adults (young seniors with an average age of 69 years, and old seniors with an average age of 81 years). The task entailed response to the detection of a target (black dot) in one of four possible locations in the visual field. Relations between reflexive and voluntary shifts of attention were gauged by the degree to which flash and arrow facilitation and inhibition were observed in response to the presentation of both arrow and flash cues together in one trial. All age groups oriented reflexively in response to a flash cue and utilized the arrow cue to orient attention strategically. When flash and arrow cues were presented in quick succession and thereby competed for attention, the youngest children and oldest seniors were least efficient and flexible in their approach to the orienting task as they had difficulty modulating visual reflexes.

The mysterious myth of attention deficits and other defect stories: Contemporary issues in the developmental approach to mental retardation

Summary We began this article with brief overview of the theoretical and methodological shortcomings that led to the decades-old myth of attentional deficit as central to mental retardation. We presented a reanalysis of the available data and suggested that no empirical evidence supports any relationship between attention deficits and mental retardation per se, although available data is certainly not definitive with regard to this question. Furthermore, we suggested that certain attentional deficits may be associated with specific etiological groups. This review of research on attention among persons with mental retardation provided the context for a review of historical landmarks and contemporary innovations and issues in the developmental approach to the study of persons with mental retardation. This framework is clearly not problem-free, but its contributions to increased precision and sophistication in theory, methodology, and interpretation are essential to the study of persons with mental retardation. As compared to other approaches, the developmental one is limiting as it generally necessitates the use of more resources in the study of smaller groups, but is necessary for increased accuracy and precision in empirical findings. Greater awareness of developmental issues will inevitably lead to an increasingly heuristic and collaborative approach to research in which studies will be designed to complement one onother. Ultimately, the products of these collaborations will provide information that is optimally helpful to persons with mental retardation, their families, and those who work with them.

Cognitive and Behavioural Development of Israeli Males with Fragile X and Down Syndrome

Hebrew translations of the Kaufman Assessment Battery for Children (KABC) and the Vineland Adaptive Behaviour Scales (VABS) were administered to 17 Israeli males with fragile X and 17 with Down syndrome matched for chronological and mental ages. When differences in the initial baselines were considered, the pattern of findings was generally consistent with previous reports. On the K-ABC, the males with fragile X scored higher on some subtests of the Simultaneous Domain but not on any of those of the Sequential Domain. On the VABS, superior scores of the males with fragile X on the Daily Living Skills and Communication domains is consistent with prior evidence of their relative strength on the former and the specific weakness of persons with Down syndrome on the latter. These differences between the males with fragile X and Down syndrome with regard to functioning on various domains and subdomains highlight the need to carefully examine the profiles of aetiologically homogeneous groups of persons.

The Orthogenetic Principle in the Perception of ''Forests'' and ''Trees''?

This study explores possible links between ontogenetic and microgenetic change (Werner, 1948, 1957) in the perception of stimuli with multiple levels of structure. Visual search for targets defined by local versus global structure was examined in observers aged 6, 8, 10, and 22 years. Perceptual access to each level of structure was varied by using pattern elements of same (easy) or opposite contrast polarity (hard); attentional processes were isolated from sensory processes by varying the number of display items. The results showed large improvements with age in search rates for global targets, with search rates for local targets being more constant over age. This pattern held regardless of whether perceptual access to a target was easy or hard. These results support the view that the perception of local and global structure involves different underlying processes.