Electronically Switchable Sham Transcranial Magnetic Stimulation (TMS) System

Transcranial magnetic stimulation (TMS) is increasingly being used to demonstrate the causal links between brain and behavior in humans. Further, extensive clinical trials are being conducted to investigate the therapeutic role of TMS in disorders such as depression. Because TMS causes strong peripheral effects such as auditory clicks and muscle twitches, experimental artifacts such as subject bias and placebo effect are clear concerns. Several sham TMS methods have been developed, but none of the techniques allows one to intermix real and sham TMS on a trial-by-trial basis in a double-blind manner. We have developed an attachment that allows fast, automated switching between Standard TMS and two types of control TMS (Sham and Reverse) without movement of the coil or reconfiguration of the setup. We validate the setup by performing mathematical modeling, search-coil and physiological measurements. To see if the stimulus conditions can be blinded, we conduct perceptual discrimination and sensory perception studies. We verify that the physical properties of the stimulus are appropriate, and that successive stimuli do not contaminate each other. We find that the threshold for motor activation is significantly higher for Reversed than for Standard stimulation, and that Sham stimulation entirely fails to activate muscle potentials. Subjects and experimenters perform poorly at discriminating between Sham and Standard TMS with a figure-of-eight coil, and between Reverse and Standard TMS with a circular coil. Our results raise the possibility of utilizing this technique for a wide range of applications

Applications of Multivariate Pattern Classification Analyses in Developmental Neuroimaging of Healthy and Clinical Populations

Analyses of functional and structural imaging data typically involve testing hypotheses at each voxel in the brain. However, it is often the case that distributed spatial patterns may be a more appropriate metric for discriminating between conditions or groups. Multivariate pattern analysis has been gaining traction in neuroimaging of adult healthy and clinical populations; studies have shown that information present in neuroimaging data can be used to decode intentions and perceptual states, as well as discriminate between healthy and diseased brains. While few studies to date have applied these methods in pediatric populations, in this review we discuss exciting potential applications for studying both healthy, and aberrant, brain development. We include an overview of methods and discussion of challenges and limitations

Impact of mentoring on socio�emotional and mental health outcomes of youth with learning disabilities and attention�deficit hyperactivity disorder

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/151880/1/camh12331_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/151880/2/camh12331.pd

Aberrant Neural Function During Emotion Attribution in Female Subjects With Fragile X Syndrome

Objective: Fragile X (FraX) syndrome is caused by mutations of the FraX mental retardation-1 gene—a gene responsible for producing FraX mental retardation protein. The neurocognitive phenotype associated with FraX in female subjects includes increased risk for emotional disorders including social anxiety, depression, and attention deficit. Here, the authors investigated the neurobiological systems underlying emotion attribution in female subjects with FraX syndrome. Method: While undergoing functional magnetic resonance imaging, 10 high-functioning female subjects with FraX syndrome and 10 typically developing (TD) female subjects were presented with photographs of happy, sad, and neutral faces and instructed to determine the facial emotion. Results: No significant group differences were found for the recognition of happy faces, although the FraX group showed a trend toward a significant difference for the recognition of sad faces and significantly poorer recognition of neutral faces. Controlling for between-group differences in IQ and performance accuracy, the TD group had greater activation than the FraX group in the anterior cingulate cortex (ACC) for neutral faces compared with scrambled faces and the caudate for sad faces compared with scrambled faces (but not for sad faces compared with neutral faces). In the FraX group, FraX mental retardation protein levels positively correlated with activation in the dorsal ACC for neutral, happy, and sad faces when independently compared with scrambled faces. Significantly greater negative correlation between IQ and insula activation for neutral faces relative to scrambled faces was observed in the FraX group compared with the TD group. Significantly greater positive correlation between IQ and ACC activation for neutral faces relative to scrambled faces was observed in the TD group compared with the FraX group. Conclusions: Although emotion recognition is generally spared in FraX syndrome, the emotion circuit (i.e., ACC, caudate, insula) that modulates emotional responses to facial stimuli may be disrupted

Direct and indirect contributions of executive function to word decoding and reading comprehension in kindergarten

Extant research is increasingly recognizing the contribution of executive function (EF) to reading comprehension alongside established predictors like word decoding and oral language. The nature of the association between EF and reading comprehension is commonly investigated in older children and in those with reading impairments. However, less is known about this relationship in emerging readers in kindergarten, where word decoding and reading comprehension are highly intertwined. Moreover, a better understanding of the mechanisms by which EF influences reading comprehension is needed. The present study investigated direct contributions of EF to reading comprehension, as well as indirect contributions via word decoding in 97 kindergarteners. Results indicated that there was a significant indirect effect of EF on reading comprehension, with word decoding mediating this association. The direct contribution of EF to reading comprehension was not significant. Implications for reading instruction and intervention for early readers are discussed.NICHDUnited States Department of Health & Human ServicesNational Institutes of Health (NIH) - USANIH Eunice Kennedy Shriver National Institute of Child Health & Human Development (NICHD) [R01HD078351, R01HD086168, R01HD096261, R01HD094834, P50HD052120]; National Science FoundationNational Science Foundation (NSF) [NSF-1540854]; University of California Office of the President Multicampus Research Programs and Initiatives AwardUniversity of California System [MRP-17-454925]; Oak Foundation [ORIO-16-012, OCAY-19-215]; UCSF Dyslexia Center; Dyslexia Training Institute; The Potter Family; ALTA; San Mateo County of Education; IMBES; SfN; Hyde Park Day School; University of Chicago Laboratory Schools24 month embargo; published online: 25 September 2019This item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]