R-3 Repository :: Browsing by Author "Dragoi, Valentin"

Browsing by Author "Dragoi, Valentin"

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25th Annual Computational Neuroscience Meeting: CNS-2016
(BioMed Central, 2016) Sharpee, Tatyana O.; Destexhe, Alain; Kawato, Mitsuo; Sekulić, Vladislav; Skinner, Frances K.; Wójcik, Daniel K.; Chintaluri, Chaitanya; Cserpán, Dorottya; Somogyvári, Zoltán; Kim, Jae K.; Kilpatrick, Zachary P.; Bennett, Matthew R.; Josić, Kresimir; Elices, Irene; Arroyo, David; Levi, Rafael; Rodriguez, Francisco B.; Varona, Pablo; Hwang, Eunjin; Kim, Bowon; Han, Hio-Been; Kim, Tae; McKenna, James T.; Brown, Ritchie E.; McCarley, Robert W.; Choi, Jee H.; Rankin, James; Popp, Pamela O.; Rinzel, John; Tabas, Alejandro; Rupp, André; Balaguer-Ballester, Emili; Maturana, Matias I.; Grayden, David B.; Cloherty, Shaun L.; Kameneva, Tatiana; Ibbotson, Michael R.; Meffin, Hamish; Koren, Veronika; Lochmann, Timm; Dragoi, Valentin; Obermayer, Klaus; Psarrou, Maria; Schilstra, Maria; Davey, Neil; Torben-Nielsen, Benjamin; Steuber, Volker; Ju, Huiwen; Yu, Jiao; Hines, Michael L.; Chen, Liang; Yu, Yuguo; Kim, Jimin; Leahy, Will; Shlizerman, Eli; Birgiolas, Justas; Gerkin, Richard C.; Crook, Sharon M.; Viriyopase, Atthaphon; Memmesheimer, Raoul-Martin; Gielen, Stan; Dabaghian, Yuri; DeVito, Justin; Perotti, Luca; Kim, Anmo J.; Fenk, Lisa M.; Cheng, Cheng; Maimon, Gaby; Zhao, Chang; Widmer, Yves; Sprecher, Simon; Senn, Walter; Halnes, Geir; Mäki-Marttunen, Tuomo; Keller, Daniel; Pettersen, Klas H.; Andreassen, Ole A.; Einevoll, Gaute T.; Yamada, Yasunori; Steyn-Ross, Moira L.; Alistair Steyn-Ross, D.; Mejias, Jorge F.; Murray, John D.; Kennedy, Henry; Wang, Xiao-Jing; Kruscha, Alexandra; Grewe, Jan; Benda, Jan; Lindner, Benjamin; Badel, Laurent; Ohta, Kazumi; Tsuchimoto, Yoshiko; Kazama, Hokto; Kahng, B.; Tam, Nicoladie D.; Pollonini, Luca; Zouridakis, George; Soh, Jaehyun; Kim, DaeEun; Yoo, Minsu; Palmer, S.E.; Culmone, Viviana; Bojak, Ingo; Ferrario, Andrea; Merrison-Hort, Robert; Borisyuk, Roman; Kim, Chang S.; Tezuka, Taro; Joo, Pangyu; Rho, Young-Ah; Burton, Shawn D.; Bard Ermentrout, G.; Jeong, Jaeseung; Urban, Nathaniel N.; Marsalek, Petr; Kim, Hoon-Hee; Moon, Seok-hyun; Lee, Do-won; Lee, Sung-beom; Lee, Ji-yong; Molkov, Yaroslav I.; Hamade, Khaldoun; Teka, Wondimu; Barnett, William H.; Kim, Taegyo; Markin, Sergey; Rybak, Ilya A.; Forro, Csaba; Dermutz, Harald; Demkó, László; Vörös, János; Babichev, Andrey; Huang, Haiping; Verduzco-Flores, Sergio; Dos Santos, Filipa; Andras, Peter; Metzner, Christoph; Schweikard, Achim; Zurowski, Bartosz; Roach, James P.; Sander, Leonard M.; Zochowski, Michal R.; Skilling, Quinton M.; Ognjanovski, Nicolette; Aton, Sara J.; Zochowski, Michal; Wang, Sheng-Jun; Ouyang, Guang; Guang, Jing; Zhang, Mingsha; Michael Wong, K.Y.; Zhou, Changsong; Robinson, Peter A.; Sanz-Leon, Paula; Drysdale, Peter M.; Fung, Felix; Abeysuriya, Romesh G.; Rennie, Chris J.; Zhao, Xuelong; Choe, Yoonsuck; Yang, Huei-Fang; Mi, Yuanyuan; Lin, Xiaohan; Wu, Si; Liedtke, Joscha; Schottdorf, Manuel; Wolf, Fred; Yamamura, Yoriko; Wickens, Jeffery R.; Rumbell, Timothy; Ramsey, Julia; Reyes, Amy; Draguljić, Danel; Hof, Patrick R.; Luebke, Jennifer; Weaver, Christina M.; He, Hu; Yang, Xu; Ma, Hailin; Xu, Zhiheng; Wang, Yuzhe; Baek, Kwangyeol; Morris, Laurel S.; Kundu, Prantik; Voon, Valerie; Agnes, Everton J.; Vogels, Tim P.; Podlaski, William F.; Giese, Martin; Kuravi, Pradeep; Vogels, Rufin; Seeholzer, Alexander; Podlaski, William; Ranjan, Rajnish; Vogels, Tim; Torres, Joaquin J.; Baroni, Fabiano; Latorre, Roberto; Gips, Bart; Lowet, Eric; Roberts, Mark J.; de Weerd, Peter; Jensen, Ole; van der Eerden, Jan; Goodarzinick, Abdorreza; Niry, Mohammad D.; Valizadeh, Alireza; Pariz, Aref; Parsi, Shervin S.; Warburton, Julia M.; Marucci, Lucia; Tamagnini, Francesco; Brown, Jon; Tsaneva-Atanasova, Krasimira; Kleberg, Florence I.; Triesch, Jochen; Moezzi, Bahar; Iannella, Nicolangelo; Schaworonkow, Natalie; Plogmacher, Lukas; Goldsworthy, Mitchell R.; Hordacre, Brenton; McDonnell, Mark D.; Ridding, Michael C.; Zapotocky, Martin; Smit, Daniel; Fouquet, Coralie; Trembleau, Alain; Dasgupta, Sakyasingha; Nishikawa, Isao; Aihara, Kazuyuki; Toyoizumi, Taro; Robb, Daniel T.; Mellen, Nick; Toporikova, Natalia; Tang, Rongxiang; Tang, Yi-Yuan; Liang, Guangsheng; Kiser, Seth A.; Howard, James H.; Goncharenko, Julia; Voronenko, Sergej O.; Ahamed, Tosif; Stephens, Greg; Yger, Pierre; Lefebvre, Baptiste; Spampinato, Giulia L.B.; Esposito, Elric; et Olivier Marre, Marcel S.; Choi, Hansol; Song, Min-Ho; Chung, SueYeon; Lee, Dan D.; Sompolinsky, Haim; Phillips, Ryan S.; Smith, Jeffrey; Chatzikalymniou, Alexandra P.; Ferguson, Katie; Alex Cayco Gajic, N.; Clopath, Claudia; Angus Silver, R.; Gleeson, Padraig; Marin, Boris; Sadeh, Sadra; Quintana, Adrian; Cantarelli, Matteo; Dura-Bernal, Salvador; Lytton, William W.; Davison, Andrew; Li, Luozheng; Zhang, Wenhao; Wang, Dahui; Song, Youngjo; Park, Sol; Choi, Ilhwan; Shin, Hee-sup; Choi, Hannah; Pasupathy, Anitha; Shea-Brown, Eric; Huh, Dongsung; Sejnowski, Terrence J.; Vogt, Simon M; Kumar, Arvind; Schmidt, Robert; Van Wert, Stephen; Schiff, Steven J.; Veale, Richard; Scheutz, Matthias; Lee, Sang W.; Gallinaro, Júlia; Rotter, Stefan; Rubchinsky, Leonid L.; Cheung, Chung C.; Ratnadurai-Giridharan, Shivakeshavan; Shomali, Safura R.; Ahmadabadi, Majid N.; Shimazaki, Hideaki; Nader Rasuli, S.; Zhao, Xiaochen; Rasch, Malte J.; Wilting, Jens; Priesemann, Viola; Levina, Anna; Rudelt, Lucas; Lizier, Joseph T.; Spinney, Richard E.; Rubinov, Mikail; Wibral, Michael; Bak, Ji H.; Pillow, Jonathan; Zaho, Yuan; Park, Il M.; Kang, Jiyoung; Park, Hae-Jeong; Jang, Jaeson; Paik, Se-Bum; Choi, Woochul; Lee, Changju; Song, Min; Lee, Hyeonsu; Park, Youngjin; Yilmaz, Ergin; Baysal, Veli; Ozer, Mahmut; Saska, Daniel; Nowotny, Thomas; Chan, Ho K.; Diamond, Alan; Herrmann, Christoph S.; Murray, Micah M.; Ionta, Silvio; Hutt, Axel; Lefebvre, Jérémie; Weidel, Philipp; Duarte, Renato; Morrison, Abigail; Lee, Jung H.; Iyer, Ramakrishnan; Mihalas, Stefan; Koch, Christof; Petrovici, Mihai A.; Leng, Luziwei; Breitwieser, Oliver; Stöckel, David; Bytschok, Ilja; Martel, Roman; Bill, Johannes; Schemmel, Johannes; Meier, Karlheinz; Esler, Timothy B.; Burkitt, Anthony N.; Kerr, Robert R.; Tahayori, Bahman; Nolte, Max; Reimann, Michael W.; Muller, Eilif; Markram, Henry; Parziale, Antonio; Senatore, Rosa; Marcelli, Angelo; Skiker, K.; Maouene, M.; Neymotin, Samuel A.; Seidenstein, Alexandra; Lakatos, Peter; Sanger, Terence D.; Menzies, Rosemary J.; McLauchlan, Campbell; van Albada, Sacha J.; Kedziora, David J.; Neymotin, Samuel; Kerr, Cliff C.; Suter, Benjamin A.; Shepherd, Gordon M.G.; Ryu, Juhyoung; Lee, Sang-Hun; Lee, Joonwon; Lee, Hyang J.; Lim, Daeseob; Wang, Jisung; Lee, Heonsoo; Jung, Nam; Anh Quang, Le; Maeng, Seung E.; Lee, Tae H.; Lee, Jae W.; Park, Chang-hyun; Ahn, Sora; Moon, Jangsup; Choi, Yun S.; Kim, Juhee; Jun, Sang B.; Lee, Seungjun; Lee, Hyang W.; Jo, Sumin; Jun, Eunji; Yu, Suin; Goetze, Felix; Lai, Pik-Yin; Kim, Seonghyun; Kwag, Jeehyun; Jang, Hyun J.; Filipović, Marko; Reig, Ramon; Aertsen, Ad; Silberberg, Gilad; Bachmann, Claudia; Buttler, Simone; Jacobs, Heidi; Dillen, Kim; Fink, Gereon R.; Kukolja, Juraj; Kepple, Daniel; Giaffar, Hamza; Rinberg, Dima; Shea, Steven; Koulakov, Alex; Bahuguna, Jyotika; Tetzlaff, Tom; Kotaleski, Jeanette H.; Kunze, Tim; Peterson, Andre; Knösche, Thomas; Kim, Minjung; Kim, Hojeong; Park, Ji S.; Yeon, Ji W.; Kim, Sung-Phil; Kang, Jae-Hwan; Lee, Chungho; Spiegler, Andreas; Petkoski, Spase; Palva, Matias J.; Jirsa, Viktor K.; Saggio, Maria L.; Siep, Silvan F.; Stacey, William C.; Bernar, Christophe; Choung, Oh-hyeon; Jeong, Yong; Lee, Yong-il; Kim, Su H.; Jeong, Mir; Lee, Jeungmin; Kwon, Jaehyung; Kralik, Jerald D.; Jahng, Jaehwan; Hwang, Dong-Uk; Kwon, Jae-Hyung; Park, Sang-Min; Kim, Seongkyun; Kim, Hyoungkyu; Kim, Pyeong S.; Yoon, Sangsup; Lim, Sewoong; Park, Choongseok; Miller, Thomas; Clements, Katie; Ahn, Sungwoo; Ji, Eoon H.; Issa, Fadi A.; Baek, JeongHun; Oba, Shigeyuki; Yoshimoto, Junichiro; Doya, Kenji; Ishii, Shin; Mosqueiro, Thiago S.; Strube-Bloss, Martin F.; Smith, Brian; Huerta, Ramon; Hadrava, Michal; Hlinka, Jaroslav; Bos, Hannah; Helias, Moritz; Welzig, Charles M.; Harper, Zachary J.; Kim, Won S.; Shin, In-Seob; Baek, Hyeon-Man; Han, Seung K.; Richter, René; Vitay, Julien; Beuth, Frederick; Hamker, Fred H.; Toppin, Kelly; Guo, Yixin; Graham, Bruce P.; Kale, Penelope J.; Gollo, Leonardo L.; Stern, Merav; Abbott, L.F.; Fedorov, Leonid A.; Giese, Martin A.; Ardestani, Mohammad H.; Faraji, Mohammad J.; Preuschoff, Kerstin; Gerstner, Wulfram; van Gendt, Margriet J.; Briaire, Jeroen J.; Kalkman, Randy K.; Frijns, Johan H.M.; Lee, Won H.; Frangou, Sophia; Fulcher, Ben D.; Tran, Patricia H.P.; Fornito, Alex; Gliske, Stephen V.; Lim, Eugene; Holman, Katherine A.; Fink, Christian G.; Kim, Jinseop S.; Mu, Shang; Briggman, Kevin L.; Sebastian Seung, H.; Wegener, Detlef; Bohnenkamp, Lisa; Ernst, Udo A.; Devor, Anna; Dale, Anders M.; Lines, Glenn T.; Edwards, Andy; Tveito, Aslak; Hagen, Espen; Senk, Johanna; Diesmann, Markus; Schmidt, Maximilian; Bakker, Rembrandt; Shen, Kelly; Bezgin, Gleb; Hilgetag, Claus-Christian; van Albada, Sacha J.; Sun, Haoqi; Sourina, Olga; Huang, Guang-Bin; Klanner, Felix; Denk, Cornelia; Glomb, Katharina; Ponce-Alvarez, Adrián; Gilson, Matthieu; Ritter, Petra; Deco, Gustavo; Witek, Maria A.G.; Clarke, Eric F.; Hansen, Mads; Wallentin, Mikkel; Kringelbach, Morten L.; Vuust, Peter; Klingbeil, Guido; De Schutter, Erik; Chen, Weiliang; Zang, Yunliang; Hong, Sungho; Takashima, Akira; Zamora, Criseida; Gallimore, Andrew R.; Goldschmidt, Dennis; Manoonpong, Poramate; Karoly, Philippa J.; Freestone, Dean R.; Soundry, Daniel; Kuhlmann, Levin; Paninski, Liam; Cook, Mark; Lee, Jaejin; Fishman, Yonatan I.; Cohen, Yale E.; Roberts, James A.; Cocchi, Luca; Sweeney, Yann; Lee, Soohyun; Jung, Woo-Sung; Kim, Youngsoo; Jung, Younginha; Song, Yoon-Kyu; Chavane, Frédéric; Soman, Karthik; Muralidharan, Vignesh; Srinivasa Chakravarthy, V.; Shivkumar, Sabyasachi; Mandali, Alekhya; Pragathi Priyadharsini, B.; Mehta, Hima; Davey, Catherine E.; Brinkman, Braden A.W.; Kekona, Tyler; Rieke, Fred; Buice, Michael; De Pittà, Maurizio; Berry, Hugues; Brunel, Nicolas; Breakspear, Michael; Marsat, Gary; Drew, Jordan; Chapman, Phillip D.; Daly, Kevin C.; Bradle, Samual P.; Seo, Sat B.; Su, Jianzhong; Kavalali, Ege T.; Blackwell, Justin; Shiau, LieJune; Buhry, Laure; Basnayake, Kanishka; Lee, Sue-Hyun; Levy, Brandon A.; Baker, Chris I; Leleu, Timothée; Philips, Ryan T.; Chhabria, Karishma
A distinct population of heterogeneously color-tuned neurons in macaque visual cortex
(AAAS, 2021) Nigam, Sunny; Pojoga, Sorin; Dragoi, Valentin
Color is a key feature of natural environments that higher mammals routinely use to detect food, avoid predators, and interpret social signals. The distribution of color signals in natural scenes is widely variable, ranging from uniform patches to highly nonuniform regions in which different colors lie in close proximity. Whether individual neurons are tuned to this high degree of variability of color signals is unknown. Here, we identified a distinct population of cells in macaque visual cortex (area V4) that have a heterogeneous receptive field (RF) structure in which individual subfields are tuned to different colors even though the full RF is only weakly tuned. This spatial heterogeneity in color tuning indicates a higher degree of complexity of color-encoding mechanisms in visual cortex than previously believed to efficiently extract chromatic information from the environment. Diverse color tuning in V4 receptive fields points to its possible role in encoding complex color stimuli in natural environment. Diverse color tuning in V4 receptive fields points to its possible role in encoding complex color stimuli in natural environment.
Adaptive coding across visual features during free-viewing and fixation conditions
(Springer Nature, 2023) Nigam, Sunny; Milton, Russell; Pojoga, Sorin; Dragoi, Valentin
Theoretical studies have long proposed that adaptation allows the brain to effectively use the limited response range of sensory neurons to encode widely varying natural inputs. However, despite this influential view, experimental studies have exclusively focused on how the neural code adapts to a range of stimuli lying along a single feature axis, such as orientation or contrast. Here, we performed electrical recordings in macaque visual cortex (area V4) to reveal significant adaptive changes in the neural code of single cells and populations across multiple feature axes. Both during free viewing and passive fixation, populations of cells improved their ability to encode image features after rapid exposure to stimuli lying on orthogonal feature axes even in the absence of initial tuning to these stimuli. These results reveal a remarkable adaptive capacity of visual cortical populations to improve network computations relevant for natural viewing despite the modularity of the functional cortical architecture.
Brain state limits propagation of neural signals in laminar cortical circuits
(National Academy of Science, 2022) Kharas, Natasha; Andrei, Ariana; Debes, Samantha R.; Dragoi, Valentin
Our perception of the environment relies on the efficient propagation of neural signals across cortical networks. During the time course of a day, neural responses fluctuate dramatically as the state of the brain changes to possibly influence how electrical signals propagate across neural circuits. Despite the importance of this issue, how patterns of spiking activity propagate within neuronal circuits in different brain states remains unknown. Here, we used multielectrode laminar arrays to reveal that brain state strongly modulates the propagation of neural activity across the layers of early visual cortex (V1). We optogenetically induced synchronized state transitions within a group of neurons and examined how far electrical signals travel during wakefulness and rest. Although optogenetic stimulation elicits stronger neural responses during wakefulness relative to rest, signals propagate only weakly across the cortical column during wakefulness, and the extent of spread is inversely related to arousal level. In contrast, the light-induced population activity vigorously propagates throughout the entire cortical column during rest, even when neurons are in a desynchronized wake-like state prior to light stimulation. Mechanistically, the influence of global brain state on the propagation of spiking activity across laminar circuits can be explained by state-dependent changes in the coupling between neurons. Our results impose constraints on the conclusions of causal manipulation studies attempting to influence neural function and behavior, as well as on previous computational models of perception assuming robust signal propagation across cortical layers and areas.
Endogenous fluctuations in cortical state selectively enhance different modes of sensory processing in human temporal lobe
(Springer Nature, 2023) Parajuli, Arun; Gutnisky, Diego; Tandon, Nitin; Dragoi, Valentin
The degree of synchronized fluctuations in neocortical network activity can vary widely during alertness. One influential idea that has emerged over the past few decades is that perceptual decisions are more accurate when the state of population activity is desynchronized. This suggests that optimal task performance may occur during a particular cortical state – the desynchronized state. Here we show that, contrary to this view, cortical state can both facilitate and suppress perceptual performance in a task-dependent manner. We performed electrical recordings from surface-implanted grid electrodes in the temporal lobe while human subjects completed two perceptual tasks. We found that when local population activity is in a synchronized state, network and perceptual performance are enhanced in a detection task and impaired in a discrimination task, but these modulatory effects are reversed when population activity is desynchronized. These findings indicate that the brain has adapted to take advantage of endogenous fluctuations in the state of neural populations in temporal cortex to selectively enhance different modes of sensory processing during perception in a state-dependent manner.
Population coding of strategic variables during foraging in freely moving macaques
(Springer Nature, 2024) Shahidi, Neda; Franch, Melissa; Parajuli, Arun; Schrater, Paul; Wright, Anthony; Pitkow, Xaq; Dragoi, Valentin
Until now, it has been difficult to examine the neural bases of foraging in naturalistic environments because previous approaches have relied on restrained animals performing trial-based foraging tasks. Here we allowed unrestrained monkeys to freely interact with concurrent reward options while we wirelessly recorded population activity in the dorsolateral prefrontal cortex. The animals decided when and where to forage based on whether their prediction of reward was fulfilled or violated. This prediction was not solely based on a history of reward delivery, but also on the understanding that waiting longer improves the chance of reward. The task variables were continuously represented in a subspace of the high-dimensional population activity, and this compressed representation predicted the animal’s subsequent choices better than the true task variables and as well as the raw neural activity. Our results indicate that monkeys’ foraging strategies are based on a cortical model of reward dynamics as animals freely explore their environment.
Precise measurement of correlations between frequency coupling and visual task performance
(Springer Nature, 2020) Young, Joseph; Dragoi, Valentin; Aazhang, Behnaam
Functional connectivity analyses focused on frequency-domain relationships, i.e. frequency coupling, powerfully reveal neurophysiology. Coherence is commonly used but neural activity does not follow its Gaussian assumption. The recently introduced mutual information in frequency (MIF) technique makes no model assumptions and measures non-Gaussian and nonlinear relationships. We develop a powerful MIF estimator optimized for correlating frequency coupling with task performance and other relevant task phenomena. In light of variance reduction afforded by multitaper spectral estimation, which is critical to precisely measuring such correlations, we propose a multitaper approach for MIF and compare its performance with coherence in simulations. Additionally, multitaper MIF and coherence are computed between macaque visual cortical recordings and their correlation with task performance is analyzed. Our multitaper MIF estimator produces low variance and performs better than all other estimators in simulated correlation analyses. Simulations further suggest that multitaper MIF captures more information than coherence. For the macaque data set, coherence and our new MIF estimator largely agree. Overall, we provide a new way to precisely estimate frequency coupling that sheds light on task performance and helps neuroscientists accurately capture correlations between coupling and task phenomena in general. Additionally, we make an MIF toolbox available for the first time.

Browsing by Author "Dragoi, Valentin"

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