Papers for the month of February 2019

"In situ 3D reconfigurable ultrasonically sculpted optical beam paths"
Optics Express, 27:7249-7265

Mouse over here for a brief summary or click to open article in a new tab.We demonstrate that optical beams can be spatially and temporally shaped in situ by forming 3D reconfigurable interference patterns of ultrasound waves in the medium. In this technique, ultrasonic pressure waves induce a modulated refractive index pattern that shapes the optical beam as it propagates through the medium. Using custom-designed cylindrical ultrasonic arrays, we demonstrate that complex patterns of light can be sculpted in the medium, including dipole and quadrupole shapes. Additionally, through a combination of theory and experiment, we demonstrate that these optical patterns can be scanned in radial and azimuthal directions. Moreover, we show that light can be selectively confined to different extrema of the spatial ultrasound pressure profile by temporally synchronizing lightwave and ultrasound. Finally, we demonstrate that this technique can also be used to define spatial patterns of light in turbid media. The notion of in situ 3D sculpting of optical beam paths using ultrasound interference patterns can find intriguing applications in biological imaging such as multipoint in vivo imaging or optogenetic stimulation deep into the brain tissue.

Carlos B., Hirshorn E., Durisko C., Fiez J.

"Word inversion sensitivity as a marker of visual word form area lateralization: An application of a novel multivariate measure of laterality"
NeuroImage, 191:493-502

Mouse over here for a brief summary or click to open article in a new tab.This work presents findings that the extent to which English readers process words in a holistic vs. part-based manner is reflected in the lateralization of word-information in their fusiform cortex multivariate activity patterns. Only a novel metric of multivariate lateralization tracked this individual difference in response-time sensitivity to word inversion. Further exploratory analyses found predictive lateralization in frontal and temporal areas.

Palacios-Barrios, E. E.

"Poverty and self-regulation: Connecting psychosocial processes, neurobiology, and the risk for psychopathology"
Comprehensive Psychiatry, 9:52-64

Mouse over here for a brief summary or click to open article in a new tab.In the United States, over 40% of youth under the age of 18 live at or near the federal poverty line. Several decades of research have established clear links between exposure to child poverty and the development of psychopathology, yet the mechanisms that convey this risk remain unclear. We review research in developmental science and other allied disciplines that identify self-regulation as a critical factor that may influence the development of psychopathology after exposure to poverty. We then connect this work with neurobiological research in an effort to further inform these associations. We propose a starting framework focused on the neural correlates of self-regulation, and discuss recent work relating poverty to alterations in brain regions related to self-regulation. We close this review by highlighting important considerations for future research on poverty/socioeconomic status, neurobiology, self-regulation, and the risks related to the development of negative mental health outcomes.

Vinod Sharma

"DRD2 Methylation and Regional Grey Matter Volumes in Young Adult Offspring from Families at Ultra-High Risk for Alcohol Dependence"
Psychiatry Research: Neuroimaging, 0:0

Mouse over here for a brief summary or click to open article in a new tab.Dopaminergic alteration is a prominent feature in those with AD and may influence brain development in those with a family history of AD. MRI scans (3T) from 43 HR offspring (27.4 + 3.6 years) and 45 controls (24.5 + 4.1 years) provided whole brain (WB) and region of interest (ROI) analyses. The VBM8 toolbox was used for WB analysis (threshold p<0.005; cluster = 100 voxels); the MarsBaR ROI toolbox provided region of interest data. Pyrosequencing of CpG sites within the DRD2 gene was performed. DRD2 methylation was significantly increased in association with familial high-risk status. Significant familial risk group differences were seen with HR individuals showing reduced volume of the Left Inferior Temporal, Left Fusiform and Left Insula regions relative to LR controls. These regions have previously been linked to social cognition. DRD2 methylation was negatively related to grey matter volumes in these regions. Because these regions, have been previously linked to facial affect perception and social cognition, lesser grey matter volumes in individuals at high-risk for developing AD suggests that neural underpinnings of social cognitive impairment may be a premorbid risk factors for AD.

Lim, Sung-joo, Fiez, Julie A.

"Role of the striatum in incidental learning of sound categories"
Proceedings of the National Academy of Sciences, 0:0

Mouse over here for a brief summary or click to open article in a new tab.Humans are born as “universal listeners” without a bias toward any particular language. However, over the first year of life, infants’ perception is shaped by learning native speech categories. Acoustically different sounds—such as the same word produced by different speakers—come to be treated as functionally equivalent. In natural environments, these categories often emerge incidentally without overt categorization or explicit feedback. However, the neural substrates of category learning have been investigated almost exclusively using overt categorization tasks with explicit feedback about categorization decisions. Here, we examined whether the striatum, previously implicated in category learning, contributes to incidental acquisition of sound categories. In the fMRI scanner, participants played a videogame in which sound category exemplars aligned with game actions and events, allowing sound categories to incidentally support successful game play. An experimental group heard nonspeech sound exemplars drawn from coherent category spaces, whereas a control group heard acoustically similar sounds drawn from a less structured space. Although the groups exhibited similar in-game performance, generalization of sound category learning and activation of the posterior striatum were significantly greater in the experimental than control group. Moreover, the experimental group showed brain–behavior relationships related to the generalization of all categories, while in the control group these relationships were restricted to the categories with structured sound distributions. Together, these results demonstrate that the striatum, through its interactions with the left superior temporal sulcus, contributes to incidental acquisition of sound category representations emerging from naturalistic learning environments.

Schneider CL, Prentiss EK, Busza A, Matmati K, Matmati N, Williams ZR, Sahin B

"Survival of retinal ganglion cells after damage to the occipital lobe in humans is activity dependent"
Proceedings of the Royal Society B, 286:1-9

Mouse over here for a brief summary or click to open article in a new tab.Damage to the optic radiations or primary visual cortex leads to trans-synaptic retrograde degeneration of retinal ganglion cells. To date, visual ability is the only predictor of retinal ganglion cell degeneration that has been investigated after geniculostriate damage. Here we find a positive relation between ganglion cell complex thickness in the blind field and early visual cortex activity for stimuli presented in the blind field.

Busza A, Schneider CL, Williams ZR, Sahin B

"Using vision to study poststroke recovery and test hypotheses about neurorehabilitation"
Neurorehabilitation and Neural Repair, 33:87-95

Mouse over here for a brief summary or click to open article in a new tab.In this article, we propose that the visual pathway has many features that make it an excellent model system for studying poststroke neuroplasticity and assessing the efficacy of therapeutic interventions.

Chen, L., Fang, X., Chang, L-Y., Fraundorf, S.

"Reading Pinyin activates sublexcial character orthography for skilled Chinese readers"
Language, Cognition and Neuroscience, 0:1-11

Mouse over here for a brief summary or click to open article in a new tab.How do skilled Chinese readers, accustomed to characters, process Pinyin, a phonemic transcription of Chinese? Does the orthography of Chinese characters become activated? In four experiments, native speakers first made a meaning judgment on a two-syllable word written in Pinyin. Immediately following, they responded to a character whose orthography sometimes was related to the character corresponding to the Pinyin. In Experiments 1 and 3, participant named the colour of the presented characters; there was an interference effect when the presented characters included phonetic radicals that were part of the character corresponding to the Pinyin. In Experiments 2 and 4, participants named the character; naming times were affected if either the semantic or phonetic radical was shared with the character corresponding to the Pinyin. The results indicate that access to lexical representations in Chinese is centred on the orthographic character, even when the input is Pinyin.

Gardner-McCune C., Martin F., Seehorn D.

"Envisioning AI for K-12: What Should Every Child Know about AI?"
Proceedings of AAAI-19, 33:0

Mouse over here for a brief summary or click to open article in a new tab.In May 2018, the Association for the Advancement of Artificial Intelligence (AAAI) and the Computer Science Teachers Association (CSTA) formed a joint initiative, chaired by David Touretzky, to develop national guidelines for teaching AI to K-12 students. This paper describes the progress to date, including a list of Five Big Ideas in AI that will serve as the organizing framework for the guidelines.

Parley B., Nicholas M., Yttri E.

"Build a better mouse task: can an open-source rodent joystick enhance reaching behavior outcomes through improved monitoring of real-time spatiotemporal kinematics?"
Biorxiv, 0:0

Mouse over here for a brief summary or click to open article in a new tab.Demonstration and full documentation of the construction an open source, inexpensive joystick manipulandum for rodents

Semedo J.D., Zandvakili A., Machens C.K., Kohn A.

"Cortical areas interact through a communication subspace"
Neuron, 102:1-11

Mouse over here for a brief summary or click to open article in a new tab.Most brain functions require the selective and flexible routing of neuronal activity between cortical areas. Using paired population recordings from multiple visual cortical areas, Semedo et al. find a population-level mechanism that can achieve this routing, termed a communication subspace.


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