Papers for the month of November 2013


"Mechanisms of auditory verbal hallucination in schizophrenia"
Frontiers in Schizohprenia, 4:155

Mouse over here for a brief summary or click to open article in a new tab.In this paper, we contrast two models of auditory verbal hallucination (AVH) in schizophrenia: a self-monitoring model and a spontaneous activation model. While postulating defects in the former is more common in explaining AVH, we argue that that it faces some significant challenges and that instead, the aberrant and spontaneous activation in relevant auditory regions should be the default model of why AVH occurs. We then outline experiments that can be done to tease the models apart.


"Solitary Alcohol Use in Teens is Associated with Drinking in Response to Negative Affect and Predicts Alcohol Problems in Young Adulthood. "
Clinical Psychological Science, in press:in press

Mouse over here for a brief summary or click to open article in a new tab.Adolescent solitary drinking may represent an informative divergence from normative behavior, with important implications for understanding risk for alcohol-use disorders later in life. Within a self-medication framework, we hypothesized that solitary alcohol use would be associated with drinking in response to negative affect and that such a pattern of drinking would predict alcohol problems in young adulthood. We tested these predictions in a longitudinal study in which we examined whether solitary drinking in adolescence (ages 12–18) predicted alcohol-use disorders in young adulthood (age 25) in 466 alcohol-using teens recruited from clinical programs and 243 alcohol-using teens recruited from the community. Findings showed that solitary drinking was associated with drinking in response to negative affect during adolescence and predicted alcohol problems in young adulthood. Results indicate that drinking alone is an important type of alcohol-use behavior that increases risk for the escalation of alcohol use and the development of alcohol problems.


"Optimizing Working Memory with Heterogeneity of Recurrent Cortical Excitation"
Journal of Neuroscience, 33:18999-19011

Mouse over here for a brief summary or click to open article in a new tab.An important neural correlate of working memory is elevated neural activity that persists long after a stimulus is removed. We use computational and theoretical analysis to show how heterogeneity in recurrent excitatory coupling can improve the stability of working memory dynamics, as well as maximize the information transfer between an input stimulus and its recall.


"Monocular Advantage for Face Perception Implicates Subcortical Mechanisms in Adult Humans."
Journal of Cognitive Neuroscience, Epub ahead of print:Epub Ahead of print

Mouse over here for a brief summary or click to open article in a new tab.Most of the work exploring the neural correlates of complex visual skills, such as face perception, has focused on cortical mechanisms. There is, however, substantial phylogenetic and ontogenetic evidence to support the engagement of lower-order structures (for example, subcortical regions) in such tasks. Here, we demonstrate that prestriate regions of cortex (i.e. the monocular portions of the visual pathway) are implicated in face perception, but not in car or word perception, even in adult humans. The representations mediated by these more rudimentary regions are somewhat coarse in nature, relative to cortical representations.


"Modulation of transcallosal inhibition by bilateral activation of agonist and antagonist proximal arm muscles"
Journal of Neurophysiology, Oct 23.:Epub ahead of print

Mouse over here for a brief summary or click to open article in a new tab.Transcallosal inhibitory interactions between proximal representations in the primary motor cortex remain poorly understood. Our findings suggest that transcallosal inhibition targeting triceps and biceps brachii is up-regulated by voluntary contraction of the contralateral agonist muscle and down-regulated by voluntary contraction of the contralateral antagonist muscle. We speculate that these reciprocal task-dependent interactions between bilateral flexor and extensor arm regions of the motor cortex may contribute to coupling between the arms during motor behavior.


"Irregular activity arises as a natural consequence of synaptic inhibition"
Chaos, 23:046110

Mouse over here for a brief summary or click to open article in a new tab.In contrast to typical "balanced network" conditions for irregular neuronal activity, we illustrate a novel mechanism by which irregular activity naturally emerges in small neuronal networks featuring coupling only by synaptic inhibition. Our mathematical analysis shows how this activity arises from the interplay of synaptic inhibition with sodium, potassium, and leak currents in a conductance-based framework; critically, the temporal details of spiking dynamics must be present for a model to exhibit this irregularity mechanism.


"Variance in population firing rate as a measure of slow time-scale correlation"
Frontiers in Computational Neuroscience, in press:in press

Mouse over here for a brief summary or click to open article in a new tab.Recent studies have shown that correlated variability is a key indicator of network state among populations of cortical neurons, yet variability is fundamentally an across-trial measure. Here we report that population variance across neurons is a suitable approximation on a single trial for correlated variability, supported by mathematical analysis, simulations of neuronal data, and recordings of groups of neurons in visual cortex.


"Comparing visual representations across human fMRI and computational vision."
Journal of Vision, 13:25

Mouse over here for a brief summary or click to open article in a new tab.We explore how well different computer vision recognition models account for neural object encoding across the human cortical visual pathway as measured using fMRI.


"DataHigh: Graphical user interface for visualizing and interacting with high-dimensional neural activity"
Journal of Neural Engineering, 10:066012

Mouse over here for a brief summary or click to open article in a new tab.DataHigh is a Matlab-based graphical user interface to visualize and interact with high-dimensional neural population activity. DataHigh has built-in tools to perform dimensionality reduction on raw spike trains, and includes a suite of visualization tools tailored for neural data analysis. The software is available for download at: http://users.ece.cmu.edu/~byronyu/software/DataHigh/datahigh.html