- Autism spectrum disorder in the scope of tactile processing. [Review]
- DCDev Cogn Neurosci 2016 Dec 23
- Sensory processing abnormalities are among the most common behavioral phenotypes seen in autism spectrum disorder (ASD), typically characterized by either over- or under-responsiveness to stimulation...
Sensory processing abnormalities are among the most common behavioral phenotypes seen in autism spectrum disorder (ASD), typically characterized by either over- or under-responsiveness to stimulation. In this review, we focus on tactile processing dysfunction in ASD. We firstly review clinical studies wherein sensitivity to tactile stimuli has traditionally been assessed by self-, parent- and experimenter-reports. We also discuss recent investigations using psychophysical paradigms that gauge individual tactile thresholds. These more experimentally rigorous studies allow for more objective assessments of tactile abnormalities in ASD. However, little is understood about the neurobiological mechanisms underlying these abnormalities, or the link between tactile abnormalities and ASD symptoms. Neurobiological research that has been conducted has pointed toward dysfunction in the excitation/inhibition balance of the central nervous system of those with ASD. This review covers recent efforts that have investigated tactile dysfunction in ASD from clinical and behavioral perspectives, and some of the efforts to link these to neurobiology. On the whole, findings are inconsistent, which can be ascribed to the subjectivity of clinical assessments, the heterogeneity of ASD cohorts, and the diversity of tactile sensitivity measures. Future endeavors into understanding tactile processing differences in ASD will greatly benefit from controlled experiments driven by neurobiological hypotheses.
- How do antidepressants influence the BOLD signal in the developing brain? [Review]
- DCDev Cogn Neurosci 2016 Dec 21
- Depression is a highly prevalent life-threatening disorder, with its first onset commonly occurring during adolescence. Adolescent depression is increasingly being treated with antidepressants, such ...
Depression is a highly prevalent life-threatening disorder, with its first onset commonly occurring during adolescence. Adolescent depression is increasingly being treated with antidepressants, such as fluoxetine. The use of medication during this sensitive period of physiological and cognitive brain development produces neurobiological changes, some of which may outlast the course of treatment. In this review, we look at how antidepressant treatment in adolescence is likely to alter neurovascular coupling and brain energy use and how these changes, in turn, affect our ability to identify neuronal activity changes between participant groups. BOLD (blood oxygen level dependent) fMRI (functional magnetic resonance imaging), the method most commonly used to record brain activity in humans, is an indirect measure of neuronal activity. This means that between-group comparisons - adolescent versus adult, depressed versus healthy, medicated versus non-medicated - rely upon a stable relationship existing between neuronal activity and the BOLD response across these groups. We use data from animal studies to detail the ways in which fluoxetine may alter this relationship, and explore how these alterations may influence the interpretation of BOLD signal differences between groups that have been treated with fluoxetine and those that have not.
- The influence of 5-HTTLPR transporter genotype on amygdala-subgenual anterior cingulate cortex connectivity in autism spectrum disorder. [Journal Article]
- DCDev Cogn Neurosci 2016 Dec 23; 24:12-20
- Social deficits in autism spectrum disorder (ASD) are linked to amygdala functioning and functional connection between the amygdala and subgenual anterior cingulate cortex (sACC) is involved in the m...
Social deficits in autism spectrum disorder (ASD) are linked to amygdala functioning and functional connection between the amygdala and subgenual anterior cingulate cortex (sACC) is involved in the modulation of amygdala activity. Impairments in behavioral symptoms and amygdala activation and connectivity with the sACC seem to vary by serotonin transporter-linked polymorphic region (5-HTTLPR) variant genotype in diverse populations. The current preliminary investigation examines whether amygdala-sACC connectivity differs by 5-HTTLPR genotype and relates to social functioning in ASD. A sample of 108 children and adolescents (44 ASD) completed an fMRI face-processing task. Youth with ASD and low expressing 5-HTTLPR genotypes showed significantly greater connectivity than youth with ASD and higher expressing genotypes as well as typically developing (TD) individuals with both low and higher expressing genotypes, in the comparison of happy vs. baseline faces and happy vs. neutral faces. Moreover, individuals with ASD and higher expressing genotypes exhibit a negative relationship between amygdala-sACC connectivity and social dysfunction. Altered amygdala-sACC coupling based on 5-HTTLPR genotype may help explain some of the heterogeneity in neural and social function observed in ASD. This is the first ASD study to combine genetic polymorphism analyses and functional connectivity in the context of a social task.
- The developmental relationship between specific cognitive domains and grey matter in the cerebellum. [Journal Article]
- DCDev Cogn Neurosci 2016 Dec 21; 24:1-11
- There is growing evidence that the cerebellum is involved in cognition and cognitive development, yet little is known about the developmental relationship between cerebellar structure and cognitive s...
There is growing evidence that the cerebellum is involved in cognition and cognitive development, yet little is known about the developmental relationship between cerebellar structure and cognitive subdomains in children. We used voxel-based morphometry to assess the relationship between cerebellar grey matter (GM) and language, reading, working memory, executive function, and processing speed in 110 individuals aged 8-17 years from the Pediatric Imaging, Neurocognition, and Genetics (PING) Study. Further, we examined the effect of age on the relationships between cerebellar GM and cognition. Higher scores on vocabulary, reading, working memory, and set-shifting were associated with increased GM in the posterior cerebellum (lobules VI-IX), in regions which are typically engaged during cognitive tasks in healthy adults. For reading, working memory, and processing speed, the relationship between cerebellar GM and cognitive performance changed with age in specific cerebellar subregions. As in adults, posterior lobe cerebellar GM was associated with cognitive performance in a pediatric population, and this relationship mirrored the known developmental trajectory of posterior cerebellar GM. These findings provide further evidence that specific regions of the cerebellum support cognition and cognitive development, and suggest that the strength of this relationship depends on developmental stage.
- Beyond dual systems: A genetically-informed, latent factor model of behavioral and self-report measures related to adolescent risk-taking. [Journal Article]
- DCDev Cogn Neurosci 2016 Dec 26
- The dual systems model posits that adolescent risk-taking results from an imbalance between a cognitive control system and an incentive processing system. Researchers interested in understanding the ...
The dual systems model posits that adolescent risk-taking results from an imbalance between a cognitive control system and an incentive processing system. Researchers interested in understanding the development of adolescent risk-taking use a diverse array of behavioral and self-report measures to index cognitive control and incentive processing. It is currently unclear whether different measures commonly interpreted as indicators of the same psychological construct do, in fact, tap the same underlying dimension of individual differences. In a diverse sample of 810 adolescent twins and triplets (M age=15.9years, SD=1.4years) from the Texas Twin Project, we investigated the factor structure of fifteen self-report and task-based measures relevant to adolescent risk-taking. These measures can be organized into four factors, which we labeled premeditation, fearlessness, cognitive dyscontrol, and reward seeking. Most behavioral measures contained large amounts of task-specific variance; however, most genetic variance in each measure was shared with other measures of the corresponding factor. Behavior genetic analyses further indicated that genetic influences on cognitive dyscontrol overlapped nearly perfectly with genetic influences on IQ (rA=-0.91). These findings underscore the limitations of using single laboratory tasks in isolation, and indicate that the study of adolescent risk taking will benefit from applying multimethod approaches.
- Interoception and psychopathology: A developmental neuroscience perspective. [Review]
- DCDev Cogn Neurosci 2016 Dec 23; 23:45-56
- Interoception refers to the perception of the physiological condition of the body, including hunger, temperature, and heart rate. There is a growing appreciation that interoception is integral to hig...
Interoception refers to the perception of the physiological condition of the body, including hunger, temperature, and heart rate. There is a growing appreciation that interoception is integral to higher-order cognition. Indeed, existing research indicates an association between low interoceptive sensitivity and alexithymia (a difficulty identifying one's own emotion), underscoring the link between bodily and emotional awareness. Despite this appreciation, the developmental trajectory of interoception across the lifespan remains under-researched, with clear gaps in our understanding. This qualitative review and opinion paper provides a brief overview of interoception, discussing its relevance for developmental psychopathology, and highlighting measurement issues, before surveying the available work on interoception across four stages of development: infancy, childhood, adolescence and late adulthood. Where gaps in the literature addressing the development of interoception exist, we draw upon the association between alexithymia and interoception, using alexithymia as a possible marker of atypical interoception. Evidence indicates that interoceptive ability varies across development, and that this variance correlates with established age-related changes in cognition and with risk periods for the development of psychopathology. We suggest a theory within which atypical interoception underlies the onset of psychopathology and risky behaviour in adolescence, and the decreased socio-emotional competence observed in late adulthood.
- A systematic review of adrenarche as a sensitive period in neurobiological development and mental health. [Review]
- DCDev Cogn Neurosci 2016 Dec 21
- Substantial hormonal and neurobiological changes occur during puberty, and are widely argued to render this period of life a sensitive period in terms of risk for mental health problems. However, the...
Substantial hormonal and neurobiological changes occur during puberty, and are widely argued to render this period of life a sensitive period in terms of risk for mental health problems. However, there is a paucity of research focusing on adrenarche, the earlier phase of pubertal development. Furthermore, there is a limited understanding of the association between adrenarche and neural development during this phase of life. We systematically reviewed research examining human adrenarcheal development as operationalized by hormonal levels of DHEA and DHEA-S, in relation to indices of mental health (Systematic Review 1). We then reviewed the limited amount of literature that has examined the association between adrenarcheal development and brain structure or function (Systematic Review 2). In general, studies showed that earlier timing of adrenarche was associated with greater mental health symptoms, and there is emerging support that brain development plays a role in this relationship. However, several methodological inconsistencies were noted. We propose that future research in this area test a theoretical model of adrenarche as a sensitive period of neurobiological development, whereby timing of exposure to hormones interacts with brain development, biological sex, and psychosocial stress to influence environmental sensitivity and risk for mental health problems through adolescence.
- But is helping you worth the risk? Defining Prosocial Risk Taking in adolescence. [Review]
- DCDev Cogn Neurosci 2016 Dec 06
- Recent work has shown that the same neural circuitry that typically underlies risky behaviors also contributes to prosocial behaviors. Despite the striking overlap between two seemingly distinct beha...
Recent work has shown that the same neural circuitry that typically underlies risky behaviors also contributes to prosocial behaviors. Despite the striking overlap between two seemingly distinct behavioral patterns, little is known about how risk taking and prosociality interact and inform adolescent decision making. We review literature on adolescent brain development as it pertains to risk taking and prosociality and propose a new area of study, Prosocial Risk Taking, which suggests that adolescents can make risky decisions with the intention of helping other individuals. Given key socialization processes and ongoing neurodevelopmental changes during this time, adolescence may represent a sensitive period for the emergence of Prosocial Risk Taking, especially within a wide variety of social contexts when youth's increased sensitivity to social evaluation and belonging impacts their behaviors. Prosocial Risk Taking in adolescence is an area of study that has been overlooked in the literature, but could help explain how ontogenetic changes in the adolescent brain may create not only vulnerabilities, but also opportunities for healthy prosocial development.
- Cortical specialisation to social stimuli from the first days to the second year of life: A rural Gambian cohort. [Journal Article]
- DCDev Cogn Neurosci 2016 Nov 27
- Brain and nervous system development in human infants during the first 1000days (conception to two years of age) is critical, and compromised development during this time (such as from under nutritio...
Brain and nervous system development in human infants during the first 1000days (conception to two years of age) is critical, and compromised development during this time (such as from under nutrition or poverty) can have life-long effects on physical growth and cognitive function. Cortical mapping of cognitive function during infancy is poorly understood in resource-poor settings due to the lack of transportable and low-cost neuroimaging methods. Having established a signature cortical response to social versus non-social visual and auditory stimuli in infants from 4 to 6 months of age in the UK, here we apply this functional Near Infrared Spectroscopy (fNIRS) paradigm to investigate social responses in infants from the first postnatal days to the second year of life in two contrasting environments: rural Gambian and urban UK. Results reveal robust, localized, socially selective brain responses from 9 to 24 months of life to both the visual and auditory stimuli. In contrast at 0-2 months of age infants exhibit non-social auditory selectivity, an effect that persists until 4-8 months when we observe a transition to greater social stimulus selectivity. These findings reveal a robust developmental curve of cortical specialisation over the first two years of life.
New Search Next
- Using fNIRS to examine occipital and temporal responses to stimulus repetition in young infants: Evidence of selective frontal cortex involvement. [Journal Article]
- DCDev Cogn Neurosci 2016 Dec 15; 23:26-38
- How does the developing brain respond to recent experience? Repetition suppression (RS) is a robust and well-characterized response of to recent experience found, predominantly, in the perceptual cor...
How does the developing brain respond to recent experience? Repetition suppression (RS) is a robust and well-characterized response of to recent experience found, predominantly, in the perceptual cortices of the adult brain. We use functional near-infrared spectroscopy (fNIRS) to investigate how perceptual (temporal and occipital) and frontal cortices in the infant brain respond to auditory and visual stimulus repetitions (spoken words and faces). In Experiment 1, we find strong evidence of repetition suppression in the frontal cortex but only for auditory stimuli. In perceptual cortices, we find only suggestive evidence of auditory RS in the temporal cortex and no evidence of visual RS in any ROI. In Experiments 2 and 3, we replicate and extend these findings. Overall, we provide the first evidence that infant and adult brains respond differently to stimulus repetition. We suggest that the frontal lobe may support the development of RS in perceptual cortices.