Aberrant neural mediation of verbal fluency in autism spectrum disorders

Objective

Contrasts of verbal fluency and automatic speech provide an opportunity to evaluate the neural underpinnings of generativity and flexibility in autism spectrum disorders (ASD).

Method

We used functional magnetic resonance imaging (fMRI) to contrast brain activity in high functioning ASD (n = 17, mean verbal IQ = 117) and neurotypical (NT; n = 20, mean verbal IQ = 112) adolescent and young adult males (12–23 years). Participants responded to three word generation conditions: automatic speech (reciting months), category fluency, and letter fluency.

Results

Our paradigm closely mirrored behavioral fluency tasks by requiring overt, free recall word generation while controlling for differences in verbal output between the groups and systematically increasing the task demand. The ASD group showed reduced neural response compared to the NT participants during fluency tasks in multiple regions of left anterior and posterior cortices, and sub-cortical structures. Six of these regions fell in cortico-striatal circuits previously linked to repetitive behaviors (Langen, Durston, Kas, van Engeland, & Staal, 2011), and activity in two of them (putamen and thalamus) was negatively correlated with autism repetitive behavior symptoms in the ASD group. In addition, response in left inferior frontal gyrus was differentially modulated in the ASD, relative to the NT, group as a function of task demand.

Conclusions

These data indicate a specific, atypical brain response in ASD to demanding generativity tasks that may have relevance to repetitive behavior symptoms in ASD as well as to difficulties generating original verbal responses.     

Effects of chewing on cognitive processing speed

In recent years, chewing has been discussed as producing effects of maintaining and sustaining cognitive performance. We have reported that chewing may improve or recover the process of working memory; however, the mechanisms underlying these phenomena are still to be elucidated. We investigated the effect of chewing on aspects of attention and cognitive processing speed, testing the hypothesis that this effect induces higher cognitive performance. Seventeen healthy adults (20–34 years old) were studied during attention task with blood oxygenation level-dependent functional (fMRI) at 3.0 T MRI. The attentional network test (ANT) within a single task fMRI containing two cue conditions (no cue and center cue) and two target conditions (congruent and incongruent) was conducted to examine the efficiency of alerting and executive control. Participants were instructed to press a button with the right or left thumb according to the direction of a centrally presented arrow. Each participant underwent two back-to-back ANT sessions with or without chewing gum, odorless and tasteless to remove any effect other than chewing. Behavioral results showed that mean reaction time was significantly decreased during chewing condition, regardless of speed-accuracy trade-off, although there were no significant changes in behavioral effects (both alerting and conflict effects). On the other hand, fMRI analysis revealed higher activations in the anterior cingulate cortex and left frontal gyrus for the executive network and motor-related regions for both attentional networks during chewing condition. These results suggested that chewing induced an increase in the arousal level and alertness in addition to an effect on motor control and, as a consequence, these effects could lead to improvements in cognitive performance.     

Individual differences in executive functioning and theory of mind: An investigation of inhibitory control and planning ability

This research examined the relative contributions of two aspects of executive function-inhibitory control and planning ability-to theory of mind in 49 3- and 4-year-olds. Children were given two standard theory of mind measures (Appearance-Reality and False Belief), three inhibitory control tasks (Bear/Dragon, Whisper, and Gift Delay), three planning tasks (Tower of Hanoi, Truck Loading, and Kitten Delivery), and a receptive vocabulary test (Peabody Picture Vocabulary Test [PPVT-3]). Multiple regression analyses indicated that two inhibition tasks (Bear/Dragon and Whisper) were significantly related to theory of mind after accounting for age, receptive vocabulary, and planning. In contrast, the planning tasks did not share unique variance with theory of mind. These results increase our understanding of the specific nature of executive function-theory of mind relations during early childhood.     

Action verbal fluency normative data for the elderly

An emerging body of literature points to the prominent role of the frontal lobes in the retrieval of verbs, whereas production of common and proper nouns arguably is mediated primarily by posterior and anterior temporal regions, respectively. Although the majority of studies examining the neuroanatomic distinctions between verb and noun retrieval have relied on action naming tasks (naming depicted activities, e.g., running) as indicators of verb retrieval abilities, recent studies have utilized an action (verb) verbal fluency measure, the Action Fluency Test (AFT), to assess verb retrieval. Findings from these studies suggest that action fluency is sensitive to the integrity of fronto-subcortical neural circuitry and that it is a valid measure of executive and language functions. The AFT is an easily administered executive function measure, but no normative data for the AFT or other action fluency tasks has been published. This study was undertaken to provide initial AFT normative data for a sample of 145 healthy elderly subjects. As education is significantly correlated with AFT scores, the normative data are stratified by educational level.     

How the mind understands other minds: cognitive psychology, attachment and reflective function

Jung's epistemological relativistic attitude was very advanced for his time and very much in line with the contemporary philosophy of science. Further, Jung states that the patient's unconscious has the capacity to represent itself by creating metaphors which give the therapist all the help he might need in treating his patient. As such, Jungian analysts have not been encouraged to embark on theoretical work and as a result, the Jungian movement has been lacking those theories that connect general psychological principles with clinical practices. In an attempt to enlarge our 'middle-range theories', we shall discuss Peter Fonagy's concept of reflective function. In our opinion, the theoretical hypothesis regarding the instinct of reading the mind (Baron-Cohen 1995) and Fonagy's idea of reflective function are extremely useful in our Jungian clinical practice and these concepts are utilizable because they are not at odds with analytical psychology's general epistemological and theoretical framework.     

Representational and executive selection resources in 'theory of mind': evidence from compromised belief-desire reasoning in old age

Effective belief-desire reasoning requires both specialized representational capacities-the capacity to represent the mental states as such-as well as executive selection processes for accurate performance on tasks requiring the prediction and explanation of the actions of social agents. Compromised belief-desire reasoning in a given population may reflect failures in either or both of these systems. We report evidence supporting this two-process model from belief-desire reasoning tasks conducted with younger and older adult populations. When task inferential complexity is held constant, neither group showed specific difficulty with reasoning about mental state content as compared with non-mental state content. However, manipulations that systematically increase executive performance demands within belief-desire reasoning caused systematic decreases in task performance in both older and younger adult groups. Moreover, the effect of increasing executive demands was disproportionately greater in the older group. Regression analysis indicated that measures of processing speed and inhibition contributed most to explaining variance in accuracy and response times in the belief-desire reasoning tasks. These results are consistent with the idea that compromised belief-desire reasoning in old age is likely the result of age-related decline in executive selection skills that supplement core mental state representational abilities, rather than as a result of failures in the representational system itself.     

A single optimum degree of hemispheric specialisation in two tasks, in two UK national birth cohorts

How differences between the two sides of the brain (or 'laterality') relate to level of function are important components of theories of the origin and purpose of hemispheric asymmetry, although different measures show different relationships, and this heterogeneity makes discerning any underlying relationships a difficult task. There are some exceptions, for example it has been concluded that increasing lateralization (eg of hand skill or planum temporale area) occurs at the expense of the non-dominant hemisphere. However, we have previously demonstrated this latter relationship to be an artefact: a consequence of plotting two variables against each other, that are not independent of each other [Leask, S. J., & Crow, T. J. (1997) How far does the brain lateralize? An unbiased method for determining the optimum degree of hemispheric specialisation. Neuropsychologia, 36, 1275-1282; Mazoyer, B. M., & Tzourio-Mazoyer, N. G. (2004). Title Planum temporale asymmetry and models of dominance for language: a reappraisal. Neuroreport, 15, 1057-1059]. Two approaches to discerning any underlying relationships are presented in data from over 20,000 10- and 11-year olds from the 1958 and 1970 UK national cohort studies. These demonstrate that maximal performance, both cognitive and hand function, is found in association with one particular degree of functional lateralization.     

Symbolic attitude and reverie: problems of symbolization in children and adolescents

In comparison to the 1970s and 1980s, we now treat more children and adolescents who, because they have had traumatic experiences of violence, child abuse, deprivation or chronic physical illness, are not able to adequately use their symbolizing function. The question is which qualities and which analytical attitude we should and can offer in analysis to help a child regain his or her capacity to symbolize, irrespective of how poorly developed or blocked this capacity may be. In contrast to Jung and some Jungians, the author argues that although the transcendent function is a 'natural process' and hence archetypally grounded as Jung maintained, the transcendent function does not work spontaneously. Rather it requires a matrix based on the child's earliest relationship, which can later be re-enacted in treatment. Jung's general concept of a 'symbolic attitude' can be complemented and focused in a specific way through the use of Bion's concept of 'reverie', which contributes in a fundamental way to symbol formation within the transference/countertransference. This idea is illustrated by clinical material from a nine-year-old boy who suffered from a severe congenital intestinal disease and was blocked in his capacity to symbolize. From the perspective of treatment technique, the author shows how the drawing of 'comic book' narratives in a reciprocal exchange was brought into the treatment. The drawings evolved in a way that he understood as a modified form of active imagination with children. The drawing process helped the boy gradually to develop a symbolic space in the therapy and to contain a psychic space in his mind.     

Task switching: a PDP model

When subjects switch between a pair of stimulus-response tasks, reaction time is slower on trial N if a different task was performed on trial N - 1. We present a parallel distributed processing (PDP) model that simulates this effect when subjects switch between word reading and color naming in response to Stroop stimuli. Reaction time on "switch trials" can be slowed by an extended response selection process which results from (a) persisting, inappropriate states of activation and inhibition of task-controlling representations; and (b) associative learning, which allows stimuli to evoke tasks sets with which they have recently been associated (as proposed by Allport & Wylie, 2000). The model provides a good fit to a large body of empirical data, including findings which have been seen as problematic for this explanation of switch costs, and shows similar behavior when the parameters are set to random values, supporting Allport and Wylie's proposal.