Figure 1: Feedforward and Horizontal connectivity in the primary visual cortex
Figure 2: Representation of an illusory motion in the primary visual cortex
Figure 3: From moving images to probabilistic representations and to decision.
The DyVA Team
The Team DyVA investigates the brain dynamics underlying visual motion perception and eye movement control or the preparation of reaching movements. A strong emphasis is put on low level perceptual mechanisms (motion integration and segmentation) and the role of context-dependant processes involved in motor preparation for goal-directed behavior such as eye movements (pursuit and saccade) or reaching/pointing.. The main objective of the team is to understand the dynamics of the cognitive brain through a tight coupling between experimental psychology, neurophysiology, imaging and computational neuroscience. Results are used to constrain computational models of optic flow processing or the behavior of neural assemblies
Technical platform
Experimental works are conducted in both human and monkey by using behavioral techniques (experimental psychology, pharmacological inactivation, microstimulation. State-of-the-art techniques in brain imaging (fMRI, real-time optical imaging) are used to investigate the temporal dynamics of cortical processes at the level of functional populations of neurons. The team operates the first European platform for optical imaging in behaving animals (link with technology). Several software (image processing, eye movements analysis, simulation) are being developed in the team
The main scientific questions
Several research programs are being currently operated. Most of them are the root for training opportunities at pre-graduate, doctoral and post-doctoral levels (link to stages)
- Active perception of visual motion. How is local motion information integrated to segregate the image of a moving object from a cluttered visual environment? We study this question using psychophysical tools and fMRI. Moreover, motion integration and segmentation processes are investigated not only during fixation but also during fast (saccade) or slow eye movements (E. Castet, G. Masson)
- Catching and pursuing a moving object. Our objective is to understand how the central nervous system extracts an object from the visual scene and determines a targeting zone for saccadic and pursuit eye movements. Our expertise extends from the dynamics of motion processing in the context of short-latency pursuit eye movements to the subcortical processes controlling of saccadic eye movements. (L. Goffart, G. Masson)
- Cognitive role of horizontal cortical interactions. Our perception and our actions are constantly under the influence of spatio-temporal contextual interactions. If visual cortical neurons see only a small part of the image, they are also interacting over large intracortical distances through horizontal axons, generating important lateral interactions (Figure 1). Real-time optical imaging offers, for the first time, the possibility to record lateral intracortical dynamics over large cortical territories. Using this technique, we investigate the functional role of cortical horizontal interactions in the emergence of a percept or an action in the awake, behaving monkey (Figure 2). (F. Chavane).
- Context-dependent dynamics in (motor) cortical networks. In order to perform a goal-directed movement, sensory (e.g. visual) information has to be transformed into an appropriate set of motor commands. Along the entire processing pathway(s), neuronal activity may be modulated specifically by the behavioural context such as expectancy or conditional probability. We investigate this contextual modulation in the behaving monkey during movement preparation and execution by using both multiple single-neuron and multiple LFP recordings in motor cortical areas, in order to decipher the role of both firing rate and synchrony, and their possible interaction (A. Riehle).
- Seing and moving the eyes without fovea. Macular diseases such as age-related macular degeneration affect deeply perceptual and motor behavior. We investigate how the visual and oculomotor systems adapt to the appearance and the further development of retinal scotomas using fMRI and video eye tracking. (J. Conrath, B. Ridings, G. Masson)
- Functional imaging of visual cortex. Optical imaging of intrinsic signals and fMRI are two powerful tools to map the functional architecture of the brain, and of the cortex in particular. Rather than measuring electrical activity directly, however, those two techniques record the hemodynamic responses triggered by the local neuronal activity, which results from sensory input. Our goal is twofold : (i) to better understand the relationship between neuronal activity and the various components of the hemodynamic response, to allow a correct interpretation of the recorded signals in term of the underlying neuronal activity, and (ii) to develop high resolution fMRI techniques for the mapping of the visual cortex in human and non-human primates. (I. Vanzetta, F. Chavane, N. Wottawa, G. Masson)
- Inferential models and spiking neural networks for the visual detection of motion. We model the dynamical properties of the perception of motion in the visual flow as the interaction of elementary inferential processes at the cellular level (cortical columns) as well as the cognitive level (cortical areas). The emerging properties of the system allows to predict and understand some aspects of the psycho- and neuro-physiological observations obtained in the team and allows to propose an architecture to understand the properties of cortical processing for visual functions. In particular, it permits to compare the relative importance of feed-forward, lateral and feed-back streams of information in the visual architecture (Figure 3). (L. Perrinet)
International Collaborations
The team is involved in two European networks.
Within the "Perception and Recognition for Action" Research and Training Network, we train post-doctoral researchers in psychophysics and eye movements studies. This network is coordinated by Dr. P. Mamassian (University of Glasgow and CNRS-Paris) and involves 8 European teams in Experimental Psychology and Neuroscience which investigate the perceptual and recognition mechanism involved in the control of behaviour. This network is funded by the Vth Framework of the European Union, until 02/2006
Starting 2005, we will be member of a new Integrative Projects called FACETS. This IP is funded by the Future and Emerging Technologies action of the IST program (VIth Framework). Research efforts are devoted to understand how the brain mechanisms work at different scales, from neuron to large scale networks (biology). New computational algorithm are develop to implement and simulate these computational rules (computational neuroscience). The ultimate goal is to implement neuronal operation as analogue devices capable to performing fast, large scale and adaptive analogue computation (VLSI, physics). The network involved 16 teams from different European countries and one company (IBM). The project is coordinated by Pr. Karlheinz Meier, from the Kirchhoff Institut für Physik (Heidelberg)
Fundings
The DyVA team is funded by several national and international agencies such as the Ministère de la Recherche, le CNRS, le Conseil Général 13, l'Union Européenne.
Members
| Statutory members | |||||
|---|---|---|---|---|---|
| Eric Castet | Researcher | 04 91 16 43 34 | Bat N Bur N027 | www | |
| Frédéric Chavane | Researcher | 04 91 16 43 14 | Bat N bureau N030 | www | |
| John Conrath | PU-PH | TIMONE | |||
| Laurent Goffart | Researcher | 04 91 16 40 88 | bat N bur N023 | ||
| Guillaume Masson | Researcher | 04 91 16 43 15 | Bat N bureau N028 | ||
| Anna Montagnini | Researcher | 04.91.16.41.11 | Bat N' Bur N026 | ||
| Laurent Perrinet | Researcher | 04 91 16 43 08 | Bat N Bur N024 | www | |
| Bernard Ridings | PU-PH | 04 91 38 54 70 | TIMONE | ||
| Alexa Riehle | Researcher | 04.91.16.43.29 | Bat N | www | |
| Ivo Vanzetta | Researcher | 04 91 16 43 32 | Bat N' Bur N056 | ||
| Students | |||||
| Carlos Aguilar | Doctorant | ||||
| Giacomo Benvenuti | Doctorant | www | |||
| Amarender Bogadhi | Doctorant | 04 9 16 43 06 | |||
| Aurélie Calabrese | Doctorant | 04.91.16.42.79 | |||
| Joachim Confais | Doctorant | 04 91 16 46 53 | |||
| Jérome Fleuriet | Doctorant | ||||
| Louis Hoffart | Doctorant | TIMONE | |||
| Bjorg Kilavik | Post doctorant | 0491164358 | |||
| Frédéric Matonti | Doctorant | ||||
| Quentin Montardy | Doctorant | ||||
| Adrián Ponce Alvarez | Doctorant | 04 91 16 46 53 | Bât N | ||
| Alexandre Reynaud | Doctorant | 04 91 16 46 53 | Bat N | ||
| Sébastien Roux | Post doctorant | 04.91.16.43.58 | |||
| Claudio Simoncini | Doctorant | ||||
| Marina Yao-N'dre | Doctorant |
Publications
You'll find below the main publications of the team. The full list is available in the Publications section.
- Hamaguchi, K; Riehle, A; Brunel, N (2010 in press), « Estimating network parameters from combined dynamics of firing rate and irregularity of single neurons », Journal of Neurophysiology,
- Kilavik,B.E.; Confais,J.; Ponce-Alvarez, A.; Diesmann, M.; Riehle, A. (2010 in press), « Evoked potentials in motor cortical LFPs reflect task timing and behavioral performance », Journal of Neurophysiology,
- Barthélemy FV, Fleuriet J, Masson GS (2010), « Temporal dynamics of 2D motion integration for ocular following in macaque monkeys », Journal of Neurophysiology, 103: 1275-1282
- Bogadhi, A; Montagnini, A; Perrinet, LU; Mamassian, P; Masson, GS (2010), « Pursuing motion illusions: a realistic oculomotor framework for Bayesian inference », Vision Research , (in press)
- Chemla, S; Chavane, F (2010), « A biophysical cortical column model to study the multi-component origin of the VSD signal. », NeuroImage, (in press)
- Denker, M.; Riehle, A.; Diesmann, M.; Grün, S. (2010), « Estimating the contribution of assembly activity to cortical dynamics from spike and population measures », J Comput Neurosci, in press
- Denker, M.; Roux, S.; Lindén, H.; Diesmann, M.; Riehle, A.; Grün, S. (2010), « The local field potential reflects surplus spike synchrony », link at: arXiv:1005.0361v1,
- Guerrasio, L; Quinet, J; Büttner, U; Goffart, L (2010), « The fastigial oculomotor region and the control of foveation during fixation », Journal of Neurophysiology , in press
- Hoffart L, Matonti F, Conrath J, Ridings B, Masson GS, Chavane F (2010), « Inhibition of corneal neovascularization after alkali burn: comparison of different doses of bevacizumab in monotherapy or associated with dexamethasone. », Clinical and Experimental Ophthalmology, 38: 346-352
- Kilavik,B.E.; Riehle, A. (2010), « Timing structures neuronal activity during preparation for action », In: K. Nobre, J. Coull (eds), Attention and Time, Oxford University Press: New York, pp. 257-271,
- Kremkow J, Perrinet LU, Masson GS, Aertsen A (2010), « Functional consequences of correlated excitatory and inhibitory conductances », Journal of Computational Neurosciences, 28: 579-594
- Masson, G.S; Ilg, U.J (2010), « Dynamics of visual motion processing », Springer-Verlag. New-York, in press
- Perrinet L. (2010), « Role of homeostasis in learning sparse representations », Neural Computation, in press PDF
- Ponce-Alvarez, A; Kilavik, BE; Riehle, A (2010), « Comparison of local measures of spike time irregularity and relating variability to firing rate in motor cortical neurons », Journal of Computational Neuroscience, 29: 351-365
- Reynaud, A; Takerkart, S; Masson, GS; Chavane, F (2010), « Linear model decomposition for voltage-sensitive dye imaging signals : application in awake behaving monkey », NeuroImage , (in press)
- Riehle, A., Roux, S., Kilavik, B.E.; Grün, S. (2010), « Dynamics of motor cortical networks: the complementarity of spike synchrony and firing rate », In: Danion F, Latash ML (eds), Motor Control: Theories, experiments, and applications, Oxford University Press: New York, in press
- Tlapale E, Masson GS, Kornprobst P (2010), « Modelling the dynamics of motion integration with a new luminance-gated diffusion mechanism », Vision Research, 50: 1676-1692
- Vanzetta, I; Flynn, C; Ivanov, AI; Bernard, C; Bénar, CG (2010), « Investigation of linear coupling between single-event blood flow responses and interictal discharges in a model of experimental epilepsy », J Neurophysiology, 103: 3139-3152
- Vanzetta, I; Slovin, H (2010), « A BOLD Assumption », Frontiers in Neuroenergetics, 2. pii: 24
- Escobar MJ, Masson GS, Vieville T, Kornprobst P (2009), « Action recognition using a bio-inspired feedforward spiking network », International Journal of Computer Vision, 82: 284-301
- Escobar, M-J; Masson, G.S; Vieville, T; Kornprobst, P (2009), « Action recognition using a bio-inspired feedforward spiking network », International Journal of Computer Vision , 82: 284-301
- Hafed, Z.M; Goffart, L; Krauzlis, R.J (2009), « A neural mechanism for microsaccade generation in the primate superior colliculus », Science, 323: 940-943
- Kilavik, BE; Roux,S;Ponce-Alvarez, A;Confais,J;Grün,S;Riehle, A (2009), « Long-term modifications in motor cortical dynamics induced by intensive practice », Journal of Neuroscience, 29: 12653-12663
- Quinet, J; Goffart, L (2009), « Electrical microstimulation of the fastigial oculomotor region in the head unrestrained monkey », Journal of Neurophysiology , 102: 320-336, 2009.
- Rickert,J; Riehle, A; Aertsen, A; Rotter, S;Nawrot, MP (2009), « Dynamic encoding of movement direction in motor cortical neurons », Journal of Neuroscience, 29: 13870-13882
- Barthélemy, F; Perrinet, LU;Castet, E; Masson, GS (2008), « Dynamics of distributed 1D and 2D motion representations for short-latency ocular following », Vision Research, 48(4):501-22 PDF
- Goffart, L (2008), « Saccadic eye movements. », Squire L. (Ed.) New Encyclopedia of Neuroscience, Academic Press, Oxford, 2008,
- Hafed, Z; Goffart, L; Krauzlis, R (2008), « Superior colliculus inactivation causes stable offsets in eye position during tracking », Journal of Neuroscience , 28 : 8124-8137
- Montagnini, A; Chelazzi, L (2008), « Dynamic interaction between Go and Stop signals in the saccadic eye movement system: New evidence against the functional independence of the underlying neural mechanisms », Vision Research, sous presse
- Nawrot, MP; Boucsein, C; Rodriguez Molina, V; Riehle, A; Aertsen, A; Rotter, S (2008), « Measurements of variability dynamics in cortical spike trains », J Neurosci Methods, 169: 374-390