Podcasts about pulvinar

Link to bioRxiv paper: http://biorxiv.org/cgi/content/short/2022.12.30.520322v1?rss=1 Authors: Kaduk, K., Wilke, M., Kagan, I. Abstract: Dorsal pulvinar has been implicated in visuospatial attentional and perceptual confidence processing. Perturbations of the dorsal pulvinar also induce an overt spatial saccade bias during free choices. But it remains unclear whether the dorsal pulvinar inactivation during an oculomotor target selection based on a perceptual decision will lead to perceptual impairment or a more general orienting deficit. To address this question, we reversibly inactivated unilateral dorsal pulvinar by injecting GABA-A agonist THIP while two macaque monkeys performed a color discrimination saccade response task with varying perceptual difficulty. We used Signal Detection Theory to dissociate perceptual discrimination (dprime) and spatial selection bias (response criterion) effects. We expected a decrease in dprime if dorsal pulvinar affects perceptual discrimination and a shift in response criterion if dorsal pulvinar is mainly involved in spatial orienting. After inactivation, we observed response criterion shifts away from contralesional stimuli, especially when two competing peripheral stimuli in opposite hemifields were present, for both difficulty levels. The saccade latency for the contralesional selection increased under all conditions. Notably, the dprime and overall accuracy remained largely unaffected. Our results underline the critical contribution of the dorsal pulvinar to spatial orienting while being less important for perceptual discrimination. Copy rights belong to original authors. Visit the link for more info Podcast created by Paper Player, LLC

Link to bioRxiv paper: http://biorxiv.org/cgi/content/short/2022.12.01.518775v1?rss=1 Authors: Wu, T. Q., Kaboodvand, N., Veit, M., McGinn, R. J., Davey, Z., Datta, A., Graber, K. D., Meador, K. J., Fisher, R., Buch, V., Parvizi, J. Abstract: Neuromodulation of the anterior nuclei of the thalamus (ANT) has shown to be efficacious in patients with refractory focal epilepsy, but it is not uniformly effective. One important uncertainty is to what extent thalamic subregions other than the ANT are recruited earlier and more prominently in the propagation of seizures in patients with presumed temporal lobe epilepsy (TLE). To address this unknown, we studied 11 patients with clinical manifestations of TLE planned to undergo invasive stereo-encephalography (sEEG) monitoring. We extended cortical electrodes to reach thalamic nuclear subdivisions in the anterior (ANT), middle (mediodorsal) and or posterior (pulvinar) sites. This multisite thalamic sampling was without any adverse events. Intracranial EEG (iEEG) recordings confirmed seizure onset in medial temporal lobe, insula, orbitofrontal and temporal neocortical sites, thereby highlighting the importance of iEEG for more accurate localization of seizure foci. Visual review of EEGs documented early and prominent involvement of specific thalamic sites. Seizures originating from the same brain origin produced a stereotyped thalamic EEG signature. Visual review of EEGs, validated with single-pulse corticothalamic evoked potentials, documented early and prominent involvement of thalamic sites that would have not been predicted given the anatomy of seizure onset zones. Pulvinar was involved earlier and more prominently than other sampled nuclear subgroups in 60% of patients, even though all patients had a presumed diagnosis of TLE prior to invasive monitoring. Our findings document the feasibility and safety of multisite sampling from the human thalamus and suggest that the anatomy of thalamic involvement may not be entirely predictable on the basis of clinical information or lobar localization of seizures. Future clinical trials can establish whether offering more personalized targets for thalamic neuromodulation will lead to greater meaningful improvements in outcome. Copy rights belong to original authors. Visit the link for more info Podcast created by Paper Player, LLC

Link to bioRxiv paper: http://biorxiv.org/cgi/content/short/2022.09.28.509981v1?rss=1 Authors: Froesel, M., Gacoin, M., Clavagnier, S., Hauser, M., Goudard, Q., Ben Hamed, S. Abstract: Social communication draws on several cognitive functions such as perception, emotion recognition and attention. In a previous study, we demonstrated that macaques associate audio-visual information when processing their species-specific communicative signals. Specifically, cortical activation is inhibited when there is a mismatch between vocalisations and social visual information whereas activation is enhanced in the lateral sulcus, superior temporal sulcus as well as a larger network composed of early visual and prefrontal areas when vocalisations and social visual information match. Here, we use a similar task and functional magnetic resonance imaging to assess the role of subcortical structures. We identify three subcortical regions involved in audio-visual processing of species-specific communicative signal: the amygdala, the claustrum and the pulvinar. Like the cortex, these subcortical structures are not activated when there is a mismatch between visual and acoustic information. In contrast, the amygdala and claustrum are activated by visual, auditory congruent and audio-visual stimulations. The pulvinar responds in a task-dependent manner, along a specific spatial sensory gradient. Anterior pulvinar responds to auditory stimuli, medial pulvinar is activated by auditory, audio-visual and visual stimuli and the dorsal lateral pulvinar only responds to visual stimuli in a pure visual task. The medial pulvinar and the amygdala are the only subcortical structures integrating audio-visual social stimuli. We propose that these three structures belong to a multisensory network that modulates the perception of visual socioemotional information and vocalizations as a function of the relevance of the stimuli in the social context. Copy rights belong to original authors. Visit the link for more info Podcast created by PaperPlayer

Today we discuss the main features of Fabry Disease, Stroke in Fabry Disease, and the Pulvinar sign with Dr. Jennifer Argudo and Dr. Fernando Ortiz.

I dag, i En Uafhængig Sommer, udfolder vi det andet kapitel i Den Uafhængiges lydbog om arbejde. Andet kapitel: "Otium est pulvinar diaboli" er et gammelt udtryk. Bedre kendt som "Lediggang er roden til alt ondt". Professor Bent Meier Sørensen vil forsøge at sætte vores arbejdsliv i et kulturelt lys, og derfor kommer vi hverken udenom Luther eller udenom tanken om det hele menneske.  Vært: Lotte Larzen

Episode 1478: Our article of the day is Pulvinar nuclei.

Podcast: Brain Inspired (LS 46 · TOP 1% what is this?)Episode: BI 088 Randy O'Reilly: Simulating the Human BrainPub date: 2020-11-02 Randy and I discuss his LEABRA cognitive architecture that aims to simulate the human brain, plus his current theory about how a loop between cortical regions and the thalamus could implement predictive learning and thus solve how we learn with so few examples. We also discuss what Randy thinks is the next big thing neuroscience can contribute to AI (thanks to a guest question from Anna Schapiro), and much more. Computational Cognitive Neuroscience Laboratory.The papers we discuss or mention:The Leabra Cognitive Architecture: How to Play 20 Principles with Nature and Win!Deep Predictive Learning in Neocortex and Pulvinar.Unraveling the Mysteries of Motivation.His youTube series detailing the theory and workings of Leabra:Computational Cognitive Neuroscience.The free textbook:Computational Cognitive Neuroscience A few take-home points: Leabra has been a slow incremental project, inspired in part by Alan Newell's suggested approach.Randy began by developing a learning algorithm that incorporated both kinds of biological learning (error-driven and associative).Leabra’s core is 3 brain areas – frontal cortex, parietal cortex, and hippocampus – and has grown from there.There's a constant balance between biological realism and computational feasibility.It's important that a cognitive architecture address multiple levels- micro-scale, macro-scale, mechanisms, functions, and so on.Deep predictive learning is a possible brain mechanism whereby predictions from higher layer cortex precede input from lower layer cortex in the thalamus, where an error is computed and used to drive learning.Randy believes our metacognitive ability to know what we do and don't know is a key next function to build into AI. Timestamps:0:00 – Intro 3:54 – Skip Intro 6:20 – Being in awe 18:57 – How current AI can inform neuro 21:56 – Anna Schapiro question – how current neuro can inform AI.29:20 – Learned vs. innate cognition 33:43 – LEABRA 38:33 – Developing Leabra 40:30 – Macroscale 42:33 – Thalamus as microscale 43:22 – Thalamocortical circuitry 47:25 – Deep predictive learning 56:18 – Deep predictive learning vs. backrop 1:01:56 – 10 Hz learning cycle 1:04:58 – Better theory vs. more data 1:08:59 – Leabra vs. Spaun 1:13:59 – Biological realism 1:21:54 – Bottom-up inspiration 1:27:26 – Biggest mistake in Leabra 1:32:14 – AI consciousness 1:34:45 – How would Randy begin again? The podcast and artwork embedded on this page are from Paul Middlebrooks, which is the property of its owner and not affiliated with or endorsed by Listen Notes, Inc.

Link to bioRxiv paper: http://biorxiv.org/cgi/content/short/2020.09.16.298539v1?rss=1 Authors: Kagan, I., Gibson, L., Spanou, E., Wilke, M. Abstract: The thalamic pulvinar and the lateral intraparietal area (LIP) share reciprocal anatomical connections and are part of an extensive cortical and subcortical network involved in spatial attention and oculomotor processing. The goal of this study was to compare the effective connectivity of dorsal pulvinar (dPul) and LIP and to probe the dependency of microstimulation effects on task demands and spatial tuning properties of a given brain region. To this end, we applied unilateral electrical microstimulation in the dPul and LIP in combination with event-related BOLD fMRI in monkeys performing fixation and memory-guided saccade tasks. Microstimulation in both dPul and LIP enhanced task-related activity in monosynaptically-connected prefrontal cortex and along the superior temporal sulcus (STS) as well as in extrastriate cortex. Both dPul and LIP stimulation also elicited activity in several cortical areas in the opposite hemisphere, implying polysynaptic propagation of excitation. LIP microstimulation elicited strong activity in the opposite homotopic LIP while no homotopic activation was found during dPul stimulation. Despite extensive activation along the intraparietal sulcus evoked by LIP stimulation, there was a difference in frontal and occipital connectivity elicited by posterior and anterior LIP stimulation sites. Comparison of dPul stimulation with the adjacent but functionally distinct ventral pulvinar also showed distinct connectivity. On the level of single trial timecourses within a region, most microstimulation regions did not show task-dependence of stimulation-elicited response modulation. Across regions, however, there was an interaction between the task and the stimulation, and task-specific correlations between the initial spatial selectivity and the magnitude of stimulation effect were observed. Consequently, stimulation-elicited modulation of task-related activity was best fitted by an additive model scaled down by the initial response amplitude. In summary, we identified overlapping and distinct patterns of thalamocortical and corticocortical connectivity of the two key visuospatial areas, highlighting the dorsal bank and fundus of STS as a prominent node of shared circuitry. Spatial task-specific and partly polysynaptic modulations of cue and saccade planning delay period activity in both hemispheres exerted by unilateral pulvinar and parietal stimulation provide insight into the distributed interhemispheric processing underlying spatial behavior. Copy rights belong to original authors. Visit the link for more info

Link to bioRxiv paper: http://biorxiv.org/cgi/content/short/2020.07.23.218610v1?rss=1 Authors: Scholl, L. R., Zhang, L., Foik, A. T., Lyon, D. C. Abstract: Optogenetic tools have become of great utility in the causal analysis of systems in the brain. However, current optogenetic techniques do not reliably support both excitation and suppression of the same cells in vivo, limiting analysis and slowing research. Here we developed a novel glycoprotein-deleted rabies virus expressing two channelrhodopsin proteins, GtACR2 and Chrimson, in order to independently manipulate excitatory and inhibitory transmembrane potentials, respectively. Using this approach, we demonstrated that rodent pulvinar neurons modulate cortical size tuning and suppress flash responses, but do not drive activity in visual cortex. While our goal was primarily to develop this novel method to study the structure-function organization of thalamocortical circuits, this technique is readily applicable to study any brain region. Copy rights belong to original authors. Visit the link for more info

Snakes occupy a special place in the human brain because they’re so weird.   Thanks to 23andMe for sponsoring this video! http://www.23andme.com/minuteearth   Thanks also to our supporters on ___________________________________________   FYI: We try to leave jargon out of our videos, but if you want to learn more about this topic, here are some keywords to get your googling started: Ophidiophobia: The abnormal fear of snakes Lateral Undulation: Waves of lateral bending through the body that propel the snake forward. Trichromatic Vision: Three color receptors in the eye that allow the animal to see a wider spectrum of colors. Electroencephalogram: A non-invasive method of measuring electrical activity in the brain. ___________________________________________   Credits (and Twitter handles): Script Writer: David Goldenberg (@dgoldenberg) Script Editor: Kate Yoshida (@KateYoshida) Video Illustrator: Qingyang Chen Video Director: Kate Yoshida (@KateYoshida) Video Narrator: Kate Yoshida (@KateYoshida) With Contributions From: Emily Elert, Henry Reich, Alex Reich, Ever Salazar, Peter Reich Music by: Nathaniel Schroeder:   _________________________________________   Like our videos? Subscribe to MinuteEarth on YouTube: Support us on Patreon:   Also, say hello on: Facebook: http://goo.gl/FpAvo6 Twitter: http://goo.gl/Y1aWVC   And find us on itunes:  https://goo.gl/sfwS6n ___________________________________________   If you liked this week’s video, we think you might also like: Vsauce2 on Dragons and Snakes and Humans: https://www.youtube.com/watch?v=6grLJyqIM8E   ___________________________________________   References: Isbell, L. (2004). Snakes as agents of evolutionary change in primate brains. Journal of Human Evolution 51 (1-35). Retrieved from: https://www.ncbi.nlm.nih.gov/pubmed/16545427LoBue, V., and DeLoache, J. (2008). Detecting the Snake in the Grass: Attention to Fear-Relevant Stimuli by Adults and Young Children. Psychological Science 19:3 (284-289). Retrieved from: https://www.ncbi.nlm.nih.gov/pubmed/18315802Van Lea, W., Isbelle, L., Matsumotoa, J., Nguyen, J., Horia, E., Maiorc, R., Tomazc, R., Trana, A., Onoa, T., and Nishijoa, H. (2013) Pulvinar neurons reveal neurobiological evidence of past selection for rapid detection of snakes. PNAS 110:47 (19000-19005). Retrieved from: http://www.pnas.org/content/110/47/19000Kawai, N., and He, H. (2016). Breaking Snake Camouflage: Humans Detect Snakes More Accurately than Other Animals under Less Discernible Visual Conditions. PLoS ONE 11:10. Retrieved from: http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0164342.

NDCN Seminar on preservation of visual capacity despite injury to V1

An audio introduction to this album.

Transcript -- An audio introduction to this album.

An audio introduction to this album.

Transcript -- An audio introduction to this album.