Visual Scanning Patterns during the Dimensional Change Card Sorting Task in Children with Autism Spectrum Disorder

Morphine exposure modulates dimensional bias and set formation in anthropoids

Humans demonstrate significant behavioural advantages with particular perceptual dimensions (such as colour or shape) and when the relevant dimension is repeated in consecutive trials. These dimension-related behavioural modulations are significantly altered in neuropsychological and addiction disorders; however, their underlying mechanisms remain unclear. Here, we studied whether these behavioural modulations exist in other trichromatic primate species and whether repeated exposure to opioids influences them. In a target detection task where the target-defining dimension (colour or shape) changed trial by trial, humans exhibited shorter response time (RT) and smaller event-related electrodermal activity with colour dimension; however, macaque monkeys had shorter RT with shape dimension. Although the dimensional biases were in the opposite directions, both species were faster when the relevant dimension was repeated, compared with conditions when it changed, across consecutive trials. These indicate that both species formed dimensional sets and that resulted in a significant 'switch cost'. Scheduled and repeated exposures to morphine, which is analogous to its clinical and recreational use, significantly augmented the dimensional bias in monkeys and also changed the switch cost depending on the relevant dimension. These cognitive effects occurred when monkeys were in abstinence periods (not under acute morphine effects) but expressing significant morphine-induced conditioned place preference. These findings indicate that significant dimensional biases and set formation are evolutionarily preserved in humans' and monkeys' cognition and that repeated exposure to morphine interacts with their manifestation. Shared neural mechanisms might be involved in the long-lasting effects of morphine and expression of dimensional biases and set formation in anthropoids.

Dimension of visual information interacts with working memory in monkeys and humans

Humans demonstrate behavioural advantages (biases) towards particular dimensions (colour or shape of visual objects), but such biases are significantly altered in neuropsychological disorders. Recent studies have shown that lesions in the prefrontal cortex do not abolish dimensional biases, and therefore suggest that such biases might not depend on top-down prefrontal-mediated attention and instead emerge as bottom-up processing advantages. We hypothesised that if dimensional biases merely emerge from an enhancement of object features, the presence of visual objects would be necessary for the manifestation of dimensional biases. In a specifically-designed working memory task, in which macaque monkeys and humans performed matching based on the object memory rather than the actual object, we found significant dimensional biases in both species, which appeared as a shorter response time and higher accuracy in the preferred dimension (colour and shape dimension in humans and monkeys, respectively). Moreover, the mnemonic demands of the task influenced the magnitude of dimensional bias. Our findings in two primate species indicate that the dichotomy of top-down and bottom-up processing does not fully explain the emergence of dimensional biases. Instead, dimensional biases may emerge when processed information regarding visual object features interact with mnemonic and executive functions to guide goal-directed behaviour.

The Performance of Visual, Auditory, and Motor Cognitive Flexibility for Children with Autism Spectrum Disorder in Taiwan

PURPOSE

Few studies have tested the cognitive flexibility, specifically auditory and motor flexibility of children with ASD. This study was conducted to understand the relationship between cognitive flexibility and visual, auditory, and motor development in young children with ASD and autistic behaviors.

PARTICIPANTS AND METHODS

A purposive sampling approach was used to screen nineteen four- to five-year-old ASD children. Tests included the Autism Behavior Checklist-Taiwan Version and Cognitive Flexibility Test, which included visual, auditory, and motor cognitive flexibility subtests.

RESULTS

At the pre-switch and post-switch of three subtests, there were considerable variations in the number of ASD passing. According to the findings, children aged five had more visual cognitive flexibility than children aged four, but the lack of significant differences for the other flexibilities. The negative correlation of the three cognitive flexibilities with autistic behaviors was -0.57~-0.64.

CONCLUSION

Children with ASD have significant difficulties in switching rule tasks characterized by visual, auditory, and motor cognitive flexibility. The results suggest that visual cognitive flexibility had an age effect. The negative correlation of the three cognitive flexibilities with autistic behaviors was moderate.

A cross-cultural study showing deficits in gaze-language coordination during rapid automatized naming among individuals with ASD

Individuals with autism spectrum disorder (ASD) and their first-degree relatives demonstrate automaticity deficits reflected in reduced eye-voice coordination during rapid automatized naming (RAN), suggesting that RAN deficits may be a genetically meaningful marker of ASD language-related impairments. This study investigated whether RAN deficits in ASD extend to a language typologically distinct from English. Participants included 23 Cantonese-speaking individuals with ASD and 39 controls from Hong Kong (HK), and age- and IQ-comparable groups of previously-studied English-speaking individuals with ASD (n = 45) and controls (n = 44) from the US. Participants completed RAN on an eye tracker. Analyses examined naming time, error rate, measures of eye movement reflecting language automaticity, including eye-voice span (EVS; location of eyes versus the named item) and refixations. The HK-ASD group exhibited longer naming times and more refixations than HK-Controls, in a pattern similar to that observed in the US-ASD group. Cultural effects revealed that both HK groups showed longer EVS and more fixations than US groups. Naming time and refixation differences may be ASD-specific impairments spanning cultures/languages, whereas EVS and fixation frequency may be more variably impacted. A potential underlying mechanism of visual "stickiness" may be contributing to this breakdown in language automaticity in ASD.

The Role of Primate Prefrontal Cortex in Bias and Shift Between Visual Dimensions

Imaging and neural activity recording studies have shown activation in the primate prefrontal cortex when shifting attention between visual dimensions is necessary to achieve goals. A fundamental unanswered question is whether representations of these dimensions emerge from top-down attentional processes mediated by prefrontal regions or from bottom-up processes within visual cortical regions. We hypothesized a causative link between prefrontal cortical regions and dimension-based behavior. In large cohorts of humans and macaque monkeys, performing the same attention shifting task, we found that both species successfully shifted between visual dimensions, but both species also showed a significant behavioral advantage/bias to a particular dimension; however, these biases were in opposite directions in humans (bias to color) versus monkeys (bias to shape). Monkeys' bias remained after selective bilateral lesions within the anterior cingulate cortex (ACC), frontopolar cortex, dorsolateral prefrontal cortex (DLPFC), orbitofrontal cortex (OFC), or superior, lateral prefrontal cortex. However, lesions within certain regions (ACC, DLPFC, or OFC) impaired monkeys' ability to shift between these dimensions. We conclude that goal-directed processing of a particular dimension for the executive control of behavior depends on the integrity of prefrontal cortex; however, representation of competing dimensions and bias toward them does not depend on top-down prefrontal-mediated processes.

Dimensional bias and adaptive adjustments in inhibitory control of monkeys

Humans and macaque monkeys, performing a Wisconsin Card Sorting Test (WCST), show a significant behavioral bias to a particular sensory dimension (e.g. color or shape); however, lesions in prefrontal cortical regions do not abolish the dimensional biases in monkeys and, therefore, it has been proposed that these biases emerge in earlier stages of visual information processing. It remains unclear whether such dimensional biases are unique to the WCST, in which attention-shifting between dimensions are required, or affect other aspects of executive functions such as 'response inhibition' and 'error-induced behavioral adjustments'. To address this question, we trained six monkeys (Macaca mulatta) to perform a stop-signal task in which they had to inhibit their response when an instruction for inhibition was given by changing the color or shape of a visual stimulus. Stop Signal Reaction Time (SSRT) is an index of inhibitory processes. In all monkeys, SSRT was significantly shorter, and the probability of a successful inhibition was significantly higher, when a change in the shape dimension acted as the stop-cue. Humans show a response slowing following a failure in response inhibition and also adapt a proactive slowing after facing demands for response inhibition. We found such adaptive behavioral adjustments, with the same pattern, in monkeys' behavior; however, the dimensional bias did not modulate them. Our findings, showing dimensional bias in monkey, with the same pattern, in two different executive control tasks support the hypothesis that the bias to shape dimension emerges in early stages of visual information processing.

An examination of perseverative errors and cognitive flexibility in autism

Perseveration is a well-replicated finding in autism. The aim of this study was to examine how the context of the task influences performance with respect to this phenomenon. We randomly assigned 137 children aged 6–12 with and without autism to complete a modified card-sorting task under one of two conditions: Children were either told the sorting rules on each trial (Explicit), or were given feedback to formulate the rules themselves (Implicit). While performance was enhanced on the Explicit condition for participants without autism, the participants with autism were disadvantaged by this manipulation. In contrast, there were few differences in performance between groups on the Implicit condition. Exploratory analyses were used to examine this unexpected result; increased autism symptomology was associated with poorer performance.

Driving among Adolescents with Autism Spectrum Disorder and Attention-Deficit Hyperactivity Disorder

Over the past several decades there has been a surge of research on the contextual, biological, and psychological factors associated with transportation safety in adolescence. However, we know much less about the factors contributing to transportation safety among adolescents who do not follow a typical developmental trajectory. Adolescents with developmental disabilities (DD) such as Autism Spectrum Disorder (ASD) and Attention-Deficit/Hyperactivity Disorder (ADHD) have a wide range of behavioral and psychological deficits that may make the complex task of driving even more challenging. Because these adolescents often retain characteristic symptoms of their disorder into adulthood, it may impede their ability to achieve important milestones during the developmental transition from adolescent to adult. As the motivating force behind autonomous living and employment, the capacity for independent transportation is paramount to an adolescent’s overall success. This critical review will draw from the current body of literature on adolescent drivers with developmental disabilities to determine (1) areas of impairment; (2) safety risk factors; and (3) effective interventions for improving driving safety in this vulnerable population of adolescent drivers between the ages of 15–22. This review will also identify important unanswered research questions, and summarize the current state of the literature.

Social and Non-social Hazard Response in Drivers with Autism Spectrum Disorder

Driving is a complex task that relies on manual, cognitive, visual and social skill. The social demands of driving may be challenging for individuals with Autism Spectrum Disorder (ASD) due to known social impairments. This study investigated how drivers with ASD respond to social (e.g., pedestrians) and non-social (e.g., vehicles) hazards in a driving simulator compared to typically developing drivers. Overall, participants responded faster to social hazards than non-social hazards. It was also found that drivers with typical development reacted faster to social hazards, while drivers with ASD showed no difference in reaction time to social versus non-social hazards. Future work should further investigate how social impairments in ASD may affect driving safety.