Ashleigh Hillier

Beta-adrenergic Modulation of Cognitive Flexibility during Stress

Stress-induced activation of the locus ceruleus-norepinephrine (LC-NE) system produces significant cognitive and behavioral effects, including enhanced arousal and attention. Improvements in discrimination task performance and memory have been attributed to this stress response. In contrast, for other cognitive functions that require cognitive flexibility, increased activity of the LC-NE system may produce deleterious effects. The aim of the present study was to determine the effect of pharmacological modulation of the LC-NE system on stress-induced impairments in cognitive flexibility performance in healthy individuals. Cognitive performance, plus psychological and physiological parameters for 16 adults without any history of anxiety disorders, was assessed during four test sessions: stress and no-stress, with each condition tested after administration of propranolol and placebo. The Trier Social Stress Test, a public-speaking and mental arithmetic stressor, was presented to participants for the stress sessions, whereas a similar, but nonstressful, control task (reading, counting) was utilized for the no-stress sessions. Tests of cognitive flexibility included lexical-semantic and associative problem-solving tasks (anagrams, Compound Remote Associates Test). Visuo-spatial memory and motor processing speed tests served as control tasks. Results indicate that (1) stress impaired performance on cognitive flexibility tasks, but not control tasks; (2) compared to placebo, cognitive flexibility improved during stress with propranolol. Therefore, psychological stress, such as public speaking, negatively impacts performance on tasks requiring cognitive flexibility in normal individuals, and this effect is reversed by beta-adrenergic antagonism. This may provide support for the hypothesis that stress-related impairments in cognitive flexibility are related to the noradrenergic system.

Two-Year Evaluation of a Vocational Support Program for Adults on the Autism Spectrum

In this article the authors provide a description and evaluation of a vocational support program for adults with autism spectrum disorders (ASD). They followed 9 participants through 2 years of the program. Increases in employment rates and income were found for program participants, and 7 participants retained their initial job placements through the 2-year period. Employers rated program participants highly on a range of important job skills, although these individuals continued to experience social challenges in the workplace. Case notes offer further insight into the experiences of adults with ASD in the workplace. Overall, the results suggest that individuals on the autism spectrum can be successful in competitive, entry-level employment.

Outcomes of a Social and Vocational Skills Support Group for Adolescents and Young Adults on the Autism Spectrum.

Adolescents and young adults With autism spectrum disorders (ASD) frequently experience social isolation and vocational failure. Although social skills groups are vital, relatively feW model programs have been developed for this age group. This article revieWs the model and evaluation of the Aspirations program, an 8-Week social and vocational skills support group for adolescents and young adults With ASD. Self-report measures, including appraisal of peer relations and empathy, Were completed pre- and post-Aspirations. Data from structured observations Were also examined for changes in frequency of contributions made by group members over the course of the program. In addition, notes taken during staff meetings and feedback sessions With group members, and separately With their parents, Were revieWed for further evidence of the programs success. The results from these measures support the efficacy of the Aspirations program and provide insight into implementing a successful model for this population.

Understanding embarrassment among those with autism: breaking down the complex emotion of embarrassment among those with autism.

Scenarios manipulating various factors within the emotion of embarrassment, such as whether or not an audience was present when an embarrassing act was committed, the type of audience present, empathic embarrassment, etc., were presented to high-functioning participants with autism and comparison groups of those with learning difficulties and typically developing participants matched for verbal and nonverbal mental age. Participants were required to rate the level of embarrassment of the protagonist and justify their responses. It was predicted that those with autism would differ significantly from the comparison groups in their ratings and also their ability to provide justifications. The results showed those with autism to have difficulty with such concepts as empathic embarrassment but showed a surprisingly good understanding of other variables manipulated such as the presence of an audience.

Positive outcomes following participation in a music intervention for adolescents and young adults on the autism spectrum

Music interventions are frequently utilized with those with autism spectrum disorders (ASD) and have shown a range of benefits. However, empirical evaluations are lacking and would be a timely step forward in the field. Here we report the findings of our pilot music program for adolescents and young adults with ASD. Evaluation of the program focused on self-esteem, anxiety, and attitudes toward and relationships with peers as these are pervasive challenges for those with ASD. Pre- and post-outcome measures showed a significant increase in self-esteem, reduced self-reported anxiety, and more positive attitudes toward peers. Weekly measures taken pre- and post-each session also showed a significant reduction in self-reported ratings of anxiety. These findings provide some initial empirical support for the efficacy of music participation in treating some of the core challenges seen in ASD.

Increased Task Difficulty Results in Greater Impact of Noradrenergic Modulation of Cognitive Flexibility

Previous research suggests that the noradrenergic system modulates certain types of cognitive flexibility. This study compared various doses of beta-adrenergic antagonists for their effect on cognitive flexibility in problem solving, and how task difficulty interacts with this effect, as well as the effect of beta-adrenergic antagonists on other tasks. Anagram task performance was compared in 72 subjects using a within-subject design for propranolol at 20 mg, 40 mg, 60 mg, and placebo in a double-blinded manner, and the effects of subject ability and task difficulty were examined. We also examined the effect of the 40 mg propranolol dose on a range of other tasks. Overall, more anagram problems were solved while on propranolol 40 mg than on placebo. Subjects least able to solve the problems benefited significantly from 40 mg of propranolol. Also, for all subjects the most difficult problems were solved more quickly with propranolol 40 mg than placebo. Benefits were also seen for word fluency and backward digit span. Therefore, noradrenergic modulation of cognitive flexibility is affected by how much difficulty the subject is encountering when searching for the solution, a pattern consistent with what might be expected in an effect on the search of the semantic and associative network.

Decreased false memory for visually presented shapes and symbols among adults on the autism spectrum

Individuals with autism spectrum disorders (ASD) have been shown in some studies to be less susceptible to the verbal “false memory” effect, perhaps due to restricted semantic associative networks. High-functioning individuals with ASD can demonstrate subtle language impairments. However, relative preservation of spatial skills can also be observed. This study investigated false memory in both visual and verbal paradigms to elucidate whether adults with ASD would be more or less prone to illusory recognition in a visual paradigm that contained slides of geometric figures with minimal linguistic and semantic associative representation. In the verbal paradigm, modeled on the Deese–Roediger–McDermott method, those with ASD did not perform significantly better than a matched comparison group. In contrast, in the visual paradigm those with ASD were significantly better able to discriminate true items from lure items and were less likely to falsely recognize the lures. Findings from the visual paradigm provide further evidence of restricted associative networks in ASD, particularly in the spatial domain.

Effect of the Cold Pressor Test on Memory and Cognitive Flexibility

Cognitive flexibility is affected by stress. The cold pressor test is a known adrenergic stressor that impairs memory, but the effect on cognitive flexibility is unknown. Sixteen subjects were given cognitive flexibility and memory tasks with and without one hand immersed in cold water. Memory was impaired in the cold pressor condition but there was no effect on cognitive flexibility. The lack of a cold pressor effect on cognitive flexibility may result from an isolated effect on the peripheral noradrenergic system, whereas indirect effects due to nociception on memory may occur.

An fMRI study of semantic priming: modulation of brain activity by varying semantic distances.

Research into the acute treatment of central nervous system (CNS) injury has become a national priority, and recent progress has been remarkable. Unfortunately, this progress has not carried over to the less acute sequelae of CNS injury, which often include serious cognitive and motor disability. One particular CNS disease, stroke, is the primary cause of serious disability in adults yet treatment for the enduring effects of stroke lags significantly behind treatment for the acute illness. Such efforts often focus on work-arounds or compensation, for deficits, rather than their remediation, because this produces rapid ‘‘functional improvement.’’ We believe that understanding remediation will ultimately require a neurobiologic theory of neural circuit reorganization (remodeling), the networklevel correlate of regeneration and repair. Neural remodeling relies on powerful interconnections among and within brain regions. Successful remediation might result from appropriate manipulation of the intensity and diversity of the regional inputs and outputs that exercise these interconnections. Many neural systems provide convergent inputs to facilitate human movement. In the presence of a motor system lesion, enhanced motor, sensory, or limbic inputs converging on the motor system may partially overcome the deficit and/or evoke pathways that bypass the lesion and facilitate motor execution and motor system remodeling. In a special issue of Cognitive and Behavioral Neurology that appeared last March, from which this editorial was inadvertently omitted, we collected a number of articles on novel, neurobiologically oriented approaches for the recovery of hand movement. We hoped that in pulling together these papers, the reader could gain perspective on current efforts underway to develop rehabilitation strategies for the patient with chronic stroke that are based on neurobiologic principles. The contributions in this special issue of cognitive and behavioral neurology fell into 3 broad categories: (1) Key neurobiologic concepts associated with motor recovery after stroke: Along these lines, Floel and Cohen reviewed both the important neurobiologic underpinnings of brain plasticity and existing methodologic approaches to assess brain plasticity after stroke. Further, they discussed the problems associated with translating the key basic scientific concepts into rehabilitative strategies. (2) Plausible (theoretical) mechanisms associated with motor recovery after stroke: The neurobiologic mechanisms of motor behavior in the healthy adult and in persons with motor system stroke are represented in this volume by several contributions. Bhimani et al described the results of an investigation into the neural mechanisms producing skilled motor behavior, using tasks originally elaborated by the esteemed 20th century neuropsychologist Aleksandr Luria. Fregni and Pascual-Leone provided an account of the neural mechanisms of recovery as seen through a process of motor relearning. Hlustik and Mayer highlighted the role of motor learning as a part of the motor recovery process after stroke, focussed on the critical yet understudied topic of (possibly) maladaptive motor learning. (3) Neurobiologically oriented therapies: The final section of the issue focused on the discussion on novel rehabilitative therapies that have been developed on the basis of data from neurobiologic studies and interpretations of those data in the context of neurologic rehabilitation.ObjectiveOur purpose was to study the effect of semantic priming at varying semantic distances on brain activation during a lexical decision experiment, using functional magnetic resonance imaging (fMRI). BackgroundNeuroimaging studies have demonstrated decreased brain activation for primed versus unprimed stimuli in language areas due to semantic priming, suggesting facilitated semantic retrieval. However, the effect of varying semantic distances on brain activation has not been studied. Therefore we examined direct and indirect priming effects on cerebral activation to provide information regarding spread of activation in the semantic network. MethodsParticipants were presented with closely, distantly, and unrelated word pairs during fMRI, and asked to make a lexical decision on the second word. ResultsBehavioral measurements demonstrated significant priming effects for all semantic distances. Imaging results showed modulation of brain activation due to different semantic relationships in the left inferior frontal gyrus, bilateral middle frontal gyrus and anterior temporal lobe, and consisted of decreased magnitude of activation when primed stimuli were processed compared with unprimed stimuli, with the greatest effect observed for closely related words. ConclusionsThis study demonstrates graduated effects of semantic priming on fMRI in semantic but not attentional brain regions, contributing to explain how semantic knowledge is organized and retrieved. These findings support the network model for organization of the semantic lexicon.

Brief report: structure of personal narratives of adults with autism spectrum disorder.

Young adults with High Functioning Autism and a matched comparison group told personal narratives using a standard conversational procedure. Longest narratives were determined (i.e., number of propositions included) and scored using an analysis that looks at the organization of a narrative around a highpoint. The group with Autism Spectrum Disorder produced narratives with significantly poorer HP macrostructure and introduced proportionately fewer propositions with conjunctions. Such impairments in the ability to make sense of personal experiences both reflect and contribute to difficulty in social-emotional functioning.