Understanding functional correlations between the activities of neuron populations is vital for the analysis of neuronal networks. Analyzing large-scale neuroimaging data obtained from hundreds of neurons simultaneously poses significant visualization challenges. We developed V-NeuroStack, a novel network visualization tool to visualize data obtained using calcium imaging of spontaneous activity of neurons in a mouse brain slice as well as in vivo using two-photon imaging. V-NeuroStack creates 3D time stacks by stacking 2D time frames for a time-series dataset. It provides a web interface to explore and analyze data using both 3D and 2D visualization techniques. Previous attempts to analyze such data have been limited by the tools available to visualize large numbers of correlated activity traces. V-NeuroStack's 3D view is used to explore patterns in dynamic large-scale correlations between neurons over time. The 2D view is used to examine any timestep of interest in greater detail. Furthermore, a dual-line graph provides the ability to explore the raw and first-derivative values of activity from an individual or a functional cluster of neurons. V-NeuroStack can scale to datasets with at least a few thousand temporal snapshots. It can potentially support future advancements in in vitro and in vivo data capturing techniques to bring forth novel hypotheses by allowing unambiguous visualization of massive patterns in neuronal activity data.

Network analysis of large-scale neuroimaging data has proven to be a particularly challenging computational problem. In this study, we adapt a novel analytical tool, known as the community dynamic inference method (CommDy), which was inspired by social network theory, for the study of brain imaging data from an aging mouse model. CommDy has been successfully used in other domains in biology; this report represents its first use in neuroscience. We used CommDy to investigate aging-related changes in network parameters in the auditory and motor cortices using flavoprotein autofluorescence imaging in brain slices and in vivo . Analysis of spontaneous activations in the auditory cortex of slices taken from young and aged animals demonstrated that cortical networks in aged brains were highly fragmented compared to networks observed in young animals. Specifically, the degree of connectivity of each activated node in the aged brains was significantly lower than those seen in the young brain, and multivariate analyses of all derived network metrics showed distinct clusters of these metrics in young vs. aged brains. CommDy network metrics were then used to build a random-forests classifier based on NMDA-receptor blockade data, which successfully recapitulated the aging findings, suggesting that the excitatory synaptic substructure of the auditory cortex may be altered during aging. A similar aging-related decline in network connectivity was also observed in spontaneous activity obtained from the awake motor cortex, suggesting that the findings in the auditory cortex are reflections of general mechanisms that occur during aging. Therefore, CommDy therefore provides a new dynamic network analytical tool to study the brain and provides links between network-level and synaptic-level dysfunction in the aging brain.

Propagation of signals across the cerebral cortex is a core component of many cognitive processes and is generally thought to be mediated by direct intracortical connectivity. The thalamus, by contrast, is considered to be devoid of internal connections and organized as a collection of parallel inputs to the cortex. Here, we provide evidence that "open-loop" intrathalamic pathways involving the thalamic reticular nucleus (TRN) can support propagation of oscillatory activity across the cortex. Recent studies support the existence of open-loop thalamo-reticulo-thalamic (TC-TRN-TC) synaptic motifs in addition to traditional closed-loop architectures. We hypothesized that open-loop structural modules, when connected in series, might underlie thalamic and, therefore cortical, signal propagation. Using a supercomputing platform to simulate thousands of permutations of a thalamocortical network based on physiological data collected in mice, rats, ferrets, and cats and in which select synapses were allowed to vary both by class and individually, we evaluated the relative capacities of closed-loop and open-loop TC-TRN-TC synaptic configurations to support both propagation and oscillation. We observed that (1) signal propagation was best supported in networks possessing strong open-loop TC-TRN-TC connectivity; (2) intrareticular synapses were neither primary substrates of propagation nor oscillation; and (3) heterogeneous synaptic networks supported more robust propagation of oscillation than their homogeneous counterparts. These findings suggest that open-loop, heterogeneous intrathalamic architectures might complement direct intracortical connectivity to facilitate cortical signal propagation.

Background Understanding functional correlations between the activities of neuron populations is vital for the analysis of neuronal networks. Analyzing large-scale neuroimaging data obtained from hundreds of neurons simultaneously poses significant visualization challenges. We developed V-NeuroStack, a novel network visualization tool to visualize data obtained using calcium imaging of spontaneous activity of cortical neurons in a mouse brain slice. New Method V-NeuroStack creates 3D time stacks by stacking 2D time frames for a period of 600 seconds. It provides a web interface that enables exploration and analysis of data using a combination of 3D and 2D visualization techniques. Comparison with existing Methods Previous attempts to analyze such data have been limited by the tools available to visualize large numbers of correlated activity traces. V-NeuroStack can scale data sets with at least a few thousand temporal snapshots. Results V-NeuroStack’s 3D view is used to explore patterns in the dynamic large-scale correlations between neurons over time. The 2D view is used to examine any timestep of interest in greater detail. Furthermore, a dual-line graph provides the ability to explore the raw and first-derivative values of a single neuron or a functional cluster of neurons. Conclusions V-NeuroStack enables easy exploration and analysis of large spatio-temporal datasets using two visualization paradigms: (a) Space-Time cube (b)Two-dimensional networks, via web interface. It will support future advancements in in vitro and in vivo data capturing techniques and can bring forth novel hypotheses by permitting unambiguous visualization of large-scale patterns in the neuronal activity data.

Propagation of signals across the cerebral cortex is a core component of many cognitive processes and is generally thought to be mediated by direct intracortical connectivity. The thalamus, by contrast, is considered to be devoid of internal connections and organized as a collection of parallel inputs to the cortex. Here, we provide evidence that “open-loop” intrathalamic connections involving the thalamic reticular nucleus (TRN) can support propagation of oscillatory activity across the cortex. Recent studies support the existence of open-loop thalamo-reticulo-thalamic (TC-TRN-TC) synaptic motifs in addition to traditional closed-loop architectures. We hypothesized that open-loop structural modules, when connected in series, might underlie thalamic and, therefore cortical, signal propagation. Using a supercomputing platform to simulate thousands of permutations of a thalamo-reticular-cortical network and allowing select synapses to vary both by class and individually, we evaluated the relative capacities of closed- and open-loop TC-TRN-TC synaptic configurations to support both propagation and oscillation. We observed that 1) signal propagation was best supported in networks possessing strong open-loop TC-TRN-TC connectivity; 2) intrareticular synapses were neither primary substrates of propagation nor oscillation; and 3) heterogeneous synaptic networks supported more robust propagation of oscillation than their homogeneous counterparts. These findings suggest that open-loop heterogeneous intrathalamic architectures complement direct intracortical connectivity to facilitate cortical signal propagation. Significance Statement Interactions between the dorsal thalamus and thalamic reticular nucleus (TRN) are speculated to contribute to phenomena such as arousal, attention, sleep, and seizures. Despite the importance of the TRN, the synaptic microarchitectures forming the basis for dorsal thalamus-TRN interactions are not fully understood. The computational neural model we present incorporates “open-loop” thalamo-reticular-thalamic (TC-TRN-TC) synaptic motifs, which have been experimentally observed. We elucidate how open-loop motifs possess the capacity to shape the propagative properties of signals intrinsic to the thalamus and evaluate the wave dynamics they support relative to closed-loop TC-TRN-TC pathways and intrareticular synaptic connections. Our model also generates predictions regarding how different spatial distributions of reticulothalamic and intrareticular synapses affect these signaling properties.

Research has shown that compliance to interactive training in tasks such as movement therapy following injuries, stroke and major surgeries is sub-optimal. Efforts are being made to make the rehabilitation process a more engaging experience to motivate patients to adhere to therapy. The use of games and virtual reality has gained interest among researchers and clinicians as it may cost less than clinical therapy and can be made portable for use at home. However, without the encouragement of a physical therapist, motivating patients may be difficult. In this paper, we propose a virtual slot machine game and hypothesize that it can potentially make individuals increase time devoted to therapy. Since this game requires minimal skill for gameplay, patients can simply reach a target to trigger a reel spin. We propose that the anticipation and uncertainty of this game will capture patients’ interest and motivate them to play longer. This preliminary study with able-bodied individuals may be used to tune the testing designs for future efforts on patient populations that need to repetitively practice arm movements.

When speaking to second language learners, talkers often reduce their rate of speech to assist their listeners' understanding and comprehension. This study grants English as a Second Language subjects fine-grained, real-time control over the playback rates of lengthy audio tracks of conversational speech, and tests the subjects' listening comprehension at their desired playback speeds and at unmodified speeds. We find evidence that slower playback rates are preferred, but no evidence that such playback rates affect listener comprehension.

Since the discovery of the receptive field, scientists have tracked receptive field structure to gain insights about mechanisms of sensory processing. At the level of the thalamus and cortex, this linear filter approach has been challenged by findings that populations of cortical neurons respond in a stereotyped fashion to sensory stimuli. Here, we elucidate a possible mechanism by which gating of cortical representations occurs. All-or-none population responses (here called “ON” and “OFF” responses) were observed in vivo and in vitro in the mouse auditory cortex at near-threshold acoustic or electrical stimulation. ON-responses were associated with previously-described UP states in the auditory cortex. OFF-responses in the cortex were only eliminated by blocking GABAergic inhibition in the thalamus. Opto- and chemogenetic silencing of NTSR-positive corticothalamic layer 6 (CTL6) neurons as well as the pharmacological blocking of the thalamic reticular nucleus (TRN) retrieved the missing cortical responses, suggesting that the corticothalamic feedback inhibition via TRN controls the gating of thalamocortical activity. Moreover, the oscillation of the pre-stimulus activity of corticothalamic cells predicted the cortical ON vs. OFF responses, suggesting that underlying cortical oscillation controls thalamocortical gating. These data suggest that the thalamus may recruit cortical ensembles rather than linearly encoding ascending stimuli and that corticothalamic projections play a key role in selecting cortical ensembles for activation.

BACKGROUND:Stroke recovery studies have shown the efficacy of bimanual training on upper limb functional recovery and others have shown the efficacy of feedback technology that augments error. OBJECTIVE:In a double-blinded randomized controlled study (N = 26), we evaluated the short-term effects of bilateral arm training to foster functional recovery of a hemiparetic arm, with half of our subjects unknowingly also receiving error augmentation (where errors were visually and haptically enhanced by a robot). METHODS:Twenty-six individuals with chronic stroke were randomly assigned to practice an equivalent amount of bimanual reaching either with or without error augmentation. Participants were instructed to coordinate both arms while reaching to two targets (one for each arm) in three 45-minute treatments per week for two weeks, with a follow-up visit after one week without treatment. RESULTS:Subjects’ 2-week gains in Fugl-Meyer score averaged 2.92, and we also observed improvements Wolf Motor Functional Ability Scale average 0.21, and Motor Activity Log of 0.58 for quantity and 0.63 for quality of life scores. The extra benefit of error augmentation over the three weeks became apparent in Fugl-Meyer score only after removing an outlier from consideration. CONCLUSIONS:This modest advantage of error augmentation was detectable over a short interval encouraging further research in interactive self-rehabilitation systems that can enhance error motor recovery.

Talkers intentionally producing high-intelligibility speech for listeners in challenging situations often reduce their speech rate. This study affords listeners fine-grained control over the playback rate of a desired speech signal in varying levels of background noise, and tests listener intelligibility with their preferred and unmodified rates of speech. We find clear listener preference for decreased rates of speech as background noise increased. However, we also found degraded performance on a speech-in-noise intelligibility test relative to unmodified speech in these same conditions.

We introduce a web-based visual comparison approach for the systematic exploration of dynamic activation networks across biological datasets. Understanding the dynamics of such networks in the context of demographic factors like age is a fundamental problem in computational systems biology and neuroscience. We design visual encodings for the dynamic and community characteristics of these temporal networks. Our multi-scale approach blends nested mosaic matrices that capture temporal characteristics of the data, spatial views of the network data, Kiviat diagrams and mirror glyphs that detail the temporal behavior and community assignment of specific nodes. A top design specifically targeted at pairwise visual comparison further supports the comparative analysis of multiple dataset activations. We demonstrate the effectiveness of this approach through a case study on mouse brain network data. Domain expert feedback indicates this approach can help identify trends and anomalies in the data.

This article describes a tailored health intervention delivered on a mobile phone platform, integrating low-literacy design strategies and basic principles of behavior change, to promote increased adherence and asthma control among underserved minority adolescents. We based the intervention and design principles on theories of Human Augmentics and the Elaboration Likelihood Model. We tested the efficacy of using electronic monitoring devices that incorporate informative and persuasive elements to improve adherence to a prescribed daily medication regimen intended to reduce use of asthma rescue medications. We describe the theoretical framework, hardware and software systems, and results of user testing for design purposes and a clinical pilot study incorporating use of the device and software by the targeted population. The results of the clinical pilot study showed an 83% completion rate for the treatment as well as improved adherence. Of note, 8% and 58% of participants achieved clinically significant adherence targets at baseline and last week of the study, respectively. Rescue asthma medication use decreased from a median of 3 puffs per week at baseline to 0 puffs per week during the last week of the study.

Study of the behavior of individual members in communities of dynamic networks can help neuroscientists to understand how interactions between neurons in brain networks change over time. Visualization of those temporal features is challenging, especially for networks embedded within spatial structures, such as brain networks. In this article, the authors present the design of SwordPlots, an interactive multi-view visualization system to assist neuroscientists in their exploration of dynamic brain networks from multiple perspectives. Their visualization helps neuroscientists to understand how the functional behavior of the brain changes over time, how such behaviors are related to the spatial structure of the brain, and how communities of neurons with similar functionality evolve over time. To evaluate their application, they asked neuroscientists to use SwordPlots to examine four different mouse brain data sets. Based on feedback, their visualization design can provide neuroscientists with the ability to gain new insights into the properties of dynamic brain networks. (C) 2016 Society for Imaging Science and Technology.

Low-income and minority children suffer disproportionately high rates of asthma moribidity.1 An important contributing factor may be higher rates of low health literacy in underserved populations,2 which is associated with poor adherence3 and health outcomes.2

Algorithmically decreasing speech tempo, or “audio dilation,” can improve speech perception in attentionally demanding tasks [Gygi & Shafiro (2014), Hear. Res. 310, pp. 76–86]. On-line audio dilation [Novak, et al. (2013), Interspeech 1869–1871] is a recently developed technique that decreases the tempo of audio signals as they are generated. This pilot study investigated effects of on-line audio dilation on performance in interactive problem solving tasks. We used a Diapix task [Baker & Hazan (2011), Behav. Res. Methods 43(3), 761–770] to elicit and record spontaneous speech from pairs of participants under various dilation conditions: participants, seated in different rooms, were asked to find ten differences on two similar pictures, while their speech was either transmitted as spoken or dilated. Conditions tested include stretching one, both, or neither audio signal by 40%. Subsequent analysis shows that the technique, even using this substantial increase, did not interfere with interactive problem solving tasks, and did not lead to changes in speech production rate, measured as number of syllables per second. The lack of negative effects of on-line speech dilation provides a preliminary basis for further assessment of this method in speech perception tasks with high attentional and memory load.

Recent work has pointed to the advantages of using distorted reality to foster sensorimotor adaptations. Here we evaluate the extent to which a visuomotor discrepancy created within the large CAVE2 Hybrid Reality Environment might induce an adaptive effect in walking. This experiment specifically studied the consequences of exposure to a rotational gain that made it appear as though the subjects were turning more than actual by a ratio of 3 to 2. We then studied subjects' abilities make turns while blindfolded before and after the experience. This brief training period (~5 minutes) resulted in slightly larger turns. Such rapid adaptive responses can be interpreted as an alteration of the motor plan and possibly a recalibration of proprioceptive and vestibular senses caused by the alteration of visual input. This study provides preliminary evidence of the possibilities of using distorted reality to constructively enhance motor training and rehabilitation.

Dynamic network visualization has been a challenging topic for dynamic networks analysis, especially for spatially embedded networks like brain networks. In this paper, we present an animated interactive visualization design that combines enhanced node-link diagrams and distance matrix layouts to assist neuroscientists in their exploration of dynamic brain networks and that enables them to understand how functional connections relate to the spatial structure of the brain. Our visualization also provides the ability to observe the evolution of a network, the change in the community identities, and node behavior over time.

Background. Neurorehabilitation studies suggest that manipulation of error signals during practice can stimulate improvement in coordination after stroke. Objective. To test visual display and robotic technology that delivers augmented error signals during training, in participants with stroke. Methods. A total of 26 participants with chronic hemiparesis were trained with haptic (via robot-rendered forces) and graphic (via a virtual environment) distortions to amplify upper-extremity (UE) tracking error. In a randomized crossover design, the intervention was compared with an equivalent amount of practice without error augmentation (EA). Interventions involved three 45-minute sessions per week for 2 weeks, then 1 week of no treatment, and then 2 additional weeks of the alternate treatment. A therapist provided a visual cursor using a tracking device, and participants were instructed to match it with their hand. Haptic and visual EA was used with blinding of participant, therapist, technician-operator, and evaluator. Clinical measures of impairment were obtained at the beginning and end of each 2-week treatment phase as well as at 1 week and at 45 days after the last treatment. Results. Outcomes showed a small, but significant benefit to EA training over simple repetitive practice, with a mean 2-week improvement in Fugl-Meyer UE motor score of 2.08 and Wolf Motor Function Test of timed tasks of 1.48 s. Conclusions. This interactive technology may improve UE motor recovery of stroke-related hemiparesis.

This chapter examines aspects needed to transfer the visual information in the physical world to the virtual world by presenting how characteristics of human vision and human perception interface with a virtual environment. The advantages of VR systems for concurrent viewing of physical and virtual objects and control of vision are presented. Perception of self-motion and visual perception including vection, vergence, stereovision, size constancy, and training in VR are reviewed.