Papers for the month of June 2016


Uyar F., Shomstein S., Greenberg AS.

"Retinotopic information interacts with category selectivity in human ventral cortex."
Neuropsychologia, 2016 May 27. pii: S0028-3932(16)30173-7. doi: 10.1016/j.neuropsychologia.2016.05.022. [Epub ahead of print] PMID: 27241486 :(16)30173-7.

Mouse over here for a brief summary or click to open article in a new tab.http://Until recently, the general consensus with respect to the organization of ventral visual cortex is that early, retinotopic regions are sensitive to the spatial position of the input stimuli whereas later, higher-order regions are sensitive to the category of the input stimuli. Growing recognition of the bidirectional connectivity of the visual system has challenged this view and recent empirical evidence suggests a more interactive and graded system. Here, based on findings from functional MRI in adult observers, in which meridians and category selective regions are localized and their activation sampled, we support this latter perspective by showing that category effects are present in retinotopic cortical areas and spatial position effects are present in higher-order regions. Furthermore, the results indicate that the retinotopic and later areas are functionally connected suggesting a possible mechanism by which these seemingly disparate effects come to be intermixed in both early and later regions of the visual system.


Ruff, D.A., Alberts, J.J.

"Relating normalization to neuronal populations across cortical areas"
Journal of Neurophysiology, :

Mouse over here for a brief summary or click to open article in a new tab.Normalization is thought to underlie many sensory, motor, and cognitive processes and likely arises from interactions between neuronal populations. To gain insight into normalization mechanisms, we recorded the activity of populations of neurons in response to combinations of visual stimuli. We found that neurons that show strong normalization shared less trial-to-trial variability with other neurons in the same cortical area and more variability with neurons in other cortical areas than did units with weak normalization.


Hirshorn, E.A., Li, Y., Ward, M.J., Richardson, R.M.

"Decoding and disrupting left midfusiform gyrus activity during word reading."
Proceedings of the National Academy of Sciences, DOI:10.1073/pnas.1604126113:Epub ahead of print

Mouse over here for a brief summary or click to open article in a new tab.Whether or not brain areas exist dedicated to reading has been debated in one form or another for nearly 150 years. Using direct neural recordings, electrical brain stimulation, and pre- and post- resection neuropsychology, the results of this work show that a region of the left mid-fusiform gyrus (sometimes called the visual word form area) dynamically codes for individual words and disrupting the function of this area preferentially perturbs word and letter recognition. These results provide strong evidence for the existence of a reading specific brain area in the left fusiform and that this area plays a critical role in refining the neural representation of what we are reading over hundreds of milliseconds.


Vinci, G., Ventura, V., Smith, M.

"Separating spike count correlation from firing rate correlation"
Neural Computation, 28:849-891

Mouse over here for a brief summary or click to open article in a new tab.Spike counts can be viewed as noisy versions of firing rates, and spike count correlation (SCC) can be viewed as a noisy version of firing rate correlation (FRC). This article provides statistical methods for disambiguating time-averaged common drive from within-trial noise, thereby separating FRC from SCC. On timescales of dozens to hundreds of milliseconds, FRC is a more sensitive indicator of shared drive than SCC.


Odic, D., Feigenson, L., Halberda, J.

"The precision of mapping between number words and the approximate number system predicts children’s formal math abilities"
Journal of Experimental Child Psychology, 150:207-226

Mouse over here for a brief summary or click to open article in a new tab.Variability in the mapping between number words and approximate numerical representations is especially important for formal math abilities in early childhood.


Hwang K, Ghuman AS, Manoach DS, Jones SR, Luna B

"Frontal preparatory neural oscillations associated with cognitive control: A developmental study comparing young adults and adolescents"
NeuroImage, 136:139-148

Mouse over here for a brief summary or click to open article in a new tab.MEG results provide evidence that the maturation of inhibitory processes from adolescence to adulthood is underlied by the strengthening of dorsolateral top-down influence over the frontal eye field during the preparation to suppress a reflexive response.


Chou, Chung-Hsing

"Human neural stem cell-induced endothelial morphogenesis requires autocrine/paracrine and juxtacrine signaling."
Scientific Reports, 6:29029

Mouse over here for a brief summary or click to open article in a new tab.Transplanted neural stem cells (NSC) interact with the host brain microenvironment. A neovascularization is commonly observed in the vicinity of the cell deposit, which is correlated with behavioral improvements. To elucidate the signaling mechanisms between human NSCs and endothelial cells (ECs), these were cocultured in an in vitro model in which NSC-induced endothelial morphogenesis produced a neurovascular environment. Soluble (autocrine/paracrine) and contact–mediated (juxtacrine) signaling molecules were evaluated for two conditionally immortalized fetal NSC lines derived from the cortical anlage (CTXOE03) and ganglionic eminence (STROC05), as well as an adult EC line (D3) derived from the cerebral microvasculature of a hippocampal biopsy.These in vitro studies shed new light on the reciprocal interactions between NSCs and ECs, which are pivotal for our mechanistic understanding of the efficacy of NSC transplantation.


Rosso AL, Flatt JD, Carlson MC, Lovasi GS,Brown AF, Matthews KA, Gianaros PJ.

"Neighborhood socioeconomic status and cognitive function in late life"
American Journal of Epidemiology, 183(12):1088-97

Mouse over here for a brief summary or click to open article in a new tab.http://Neighborhood socioeconomic status (NSES) is associated with cognitive function, independently of individual demographic, health, and socioeconomic characteristics. However, research has been largely cross-sectional, and mechanisms of the association are unknown. In 1992–1993, Cardiovascular Health Study participants (n = 3,595; mean age = 74.8 years; 15.7% black) underwent cognitive testing and magnetic resonance imaging of white matter hyperintensities (WMH), and their addresses were geocoded. NSES was calculated using 1990 US Census data (block groups; 6 measures of wealth, education, and occupation). The Modified Mini-Mental State Examination (3MS) was used to assess general cognition, and the Digit Symbol Substitution Test (DSST) was used to assess speed of processing annually for 6 years. Associations of race-specific NSES tertiles with 3MS, DSST, and WMH were estimated using linear mixed-effects models accounting for geographic clustering, stratified by race, and adjusted for demographic, health, and individual socioeconomic status (education, income, lifetime occupational status) variables. In fully adjusted models, higher NSES was associated with higher 3MS scores in blacks (mean difference between highest and lowest NSES = 2.4 points; P = 0.004) and whites (mean difference = 0.7 points; P = 0.02) at baseline but not with changes in 3MS over time. NSES was marginally associated with DSST and was not associated with WMH. Adjustment for WMH did not attenuate NSES-3MS associations. Associations of NSES with cognition in late adulthood differ by race, are not explained by WMH, and are evident only at baseline.


Varma VR, Hausdorff JM, Studenski SA, Carmiciolli R, Alexander NB, Chen WG, Lipsitz LA, Carlson MC

"Aging, the Central Nervous System, and Mobility in Older Adults: Interventions"
J Gerontol A Biol Sci Med Sci, 0:0

Mouse over here for a brief summary or click to open article in a new tab.http://Research suggests that the central nervous system (CNS) and mobility are closely linked. CNS-mediated mobility impairment may represent a potentially new and prevalent syndrome within the older adult populations. Interventions targeting this group may have the potential to improve mobility and cognition and prevent disability.


Barredo J., Badre D.

"Organization of cortico-cortical pathways supporting memory retrieval across subregions of the left ventrolateral prefrontal cortex"
Journal of Neurophysiology, 0:0

Mouse over here for a brief summary or click to open article in a new tab.Using DWI tractography, this project identifies distinct pathways connecting the ventral lateral prefrontal cortex to other prefrontal, parietal and temporal regions that support different aspects of memory retrieval.


Geramita, M.A, Burton, S.D.

"Distinct lateral inhibitory circuits drive parallel processing of sensory information in the mammalian olfactory bulb"
eLife, 10:7554

Mouse over here for a brief summary or click to open article in a new tab.Splitting sensory information into parallel pathways is a common strategy in sensory systems. Yet, how circuits in these parallel pathways are composed to maintain or even enhance the encoding of specific stimulus features is poorly understood. Here, we have investigated the parallel pathways formed by mitral and tufted cells of the olfactory system in mice and characterized the emergence of feature selectivity in these cell types via distinct lateral inhibitory circuits. We find differences in activity-dependent lateral inhibition between mitral and tufted cells that likely reflect newly described differences in the activation of deep and superficial granule cells. Simulations show that these circuit-level differences allow mitral and tufted cells to best discriminate odors in separate concentration ranges, indicating that segregating information about different ranges of stimulus intensity may be an important function of these parallel sensory pathways.

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