Complexity of Cortical Dynamics During Perceptual Binding: Gamma Oscillations


Abstract

One of the most important functions of the human visual system is perceptual binding, a process that underlies our capability to perceive the world. Cortical oscillations in the gamma band have been recently shown to play a crucial role in this process. We will investigate, using high-density electroencephalographic (EEG) recordings on human subjects, the function of gamma oscillations for binding. The role of gamma activity will be studied from two perspectives. First, gamma-band oscillations could represent a mechanism for the exploration of cortical states, before finding a solution for the encoding of the visual scene. The second possibility is that gamma oscillations are a mechanism directly involved in the representation of the visual solution itself. These hypotheses will be tested using a psychophysical, perceptual binding paradigm. In parallel, we will investigate the dynamics of the EEG signalís complexity as a function of difficulty of the perceptual task. Advanced non-linear methods, based on fractal dimensionality, TESPAR descriptors and multi-dimensional pattern analysis, developed already by the members of the research group, will be applied on the recorded EEG data. By employing these methods, we intend to investigate the suggested hypothesis that neuronal systems solve problems by exploration of high-dimensional states and subsequent selection processes based on learned attractors. Special emphasis will be placed on the role of gamma oscillations during the perceptual process and their correlation with the complexity of the EEG signal. The potential implications of the project are vast. First, it will contribute to a better understanding of gamma oscillations, known to be involved in various brain disorders such as: schizophrenia, epilepsy, autism, Alzheimerís and Parkinsonís disease. Second, it will help us understand better the processes that underlie visual perception with far-reaching implications for industry and society.


Research team

Dr. Eng. Raul C. Muresan, principal investigator. Timeshare on the project > 75%.

[Personal homepage]    [Curriculum Vitae]
Dipl. Eng. Vlad V. Moca, PhD researcher. Timeshare on the project > 86%.

[Curriculum Vitae]
Ioana Tincas, PhD researcher. Timeshare on the project > 76%.

[Curriculum Vitae]
Ovidiu F. Jurjut, PhD researcher. Externally funded (Germany).

[Curriculum Vitae]
Dr. Razvan V. Florian, postdoc.

[Personal homepage]


Objectives and activities

  • Activity report for 2007 (in Romanian).
     [pdf]

  • Activity report for 2008 (in Romanian).
     [pdf]

  • Activity report for 2009 (in Romanian).
     [pdf]

  • Final activity report (2010; in Romanian).
     [pdf]



Results

  • Overview of results for 2007 (in Romanian).
     [pdf]

  • Overview of results for 2008 (in Romanian).
     [pdf]

  • Overview of results for 2009 (in Romanian).
     [pdf]

  • Overview of final results (2010; in Romanian).
     [pdf]



Publications

Articles:

  • Moca V.V., Tincas I., Melloni L., Muresan R.C. (2011), Visual exploration and object recognition by lattice deformation. PLoS One 6(7): e22831.
     [pdf]  [link]

  • Jurjut O.F., Nikolic D., Pipa G., Singer W., Metzler D., Muresan R.C. (2009), A color-based visualization technique for multi-electrode spike trains. Journal of Neurophysiology 102:3766-3778, 2009.
     [pdf]

  • Moca V.V., Scheller B., Muresan R.C., Daunderer M., Pipa G. (2009), EEG under anesthesia - feature extraction with TESPAR. Computer Methods and Programs in Biomedicine 95:191-202.
     [pdf]

  • Muresan R.C., Jurjut O.F., Moca V.V., Singer W., Nikolic D. (2008), The Oscillation Score: An Efficient Method for Estimating Oscillation Strength in Neuronal Activity. Journal of Neurophysiology 99:1333-1353.
     [pdf & free source code]

  • Nikolic D., Moca V.V., Singer W. and Muresan R.C. (2008), Properties of multivariate data investigated by fractal dimensionality. Journal of Neuroscience Methods 172(1):27-33.
    [link]

  • Muresan R.C., Singer W., Nikolic D. (2008), The InfoPhase Method or How to Read Neurons with Neurons. In V. Kurkova et al. (eds.): ICANN 2008, Part II, Lecture Notes in Computer Science 5164, pp. 498-507, Springer, Berlin / Heidelberg.
     [pdf] [link]

  • Moca V.V., Nikolic D., and Muresan R.C. (2008), Real and Modeled Spike Trains: Where Do They Meet? In V. Kurkova et al. (eds.): ICANN 2008, Part II, Lecture Notes in Computer Science 5164, pp. 488-497, Springer, Berlin / Heidelberg.
     [pdf] [link]

Abstracts, extended abstracts, posters and invited talks:

  • Muresan R.C. (2009), Combined Approaches to Understanding the Brain, invited talk at Seminari di Neuroscienze e Scienze Psichologiche e Psichiatriche, University of Verona, Verona, Italy.

  • Muresan R.C., Tincas I., Moca V.V., Melloni L. (2009), Probing the visual system with visual hypotheses, (CNS Meeting 09) Berlin Germany: BMC Neuroscience 10 (Suppl 1), p. 356.
     [pdf] [link]

  • Moca V.V., Scheller B., Muresan R.C., Daunderer M., Pipa G. (2009), EEG processing with TESPAR for depth of anesthesia detection, (CNS Meeting 09) Berlin Germany: BMC Neuroscience 10 (Suppl 1), p. 68.
     [pdf] [link]

  • Muresan R.C., Tincas I., Moca V.V., Melloni L. (2009), Vision by inference: visual recognition under uncertainty, (ASSC XIII) Berlin Germany, p. 195.
     [link]

  • Moca V.V., Scheller B., Muresan R.C., Daunderer M., Pipa G. (2009), Importance of EEG frequency bands in the assessment of depth of anesthesia, (ASSC XIII) Berlin Germany, p. 187.
     [link]

  • Muresan R.C. (2009), Investigating Brain Function from Multiple Perspectives: Modeling, Experiment, Analysis, invited talk at AHFMR Polaris Mini Workshop on Brain Dynamics, Canadian Centre for Behavioural Neuroscience, Lethbridge, Canada.

  • Muresan R.C. (2008), Dynamics of self-sustained microcircuits examined with regular-spiking readouts, (CNS Meeting 08) Portland (Oregon), USA: BMC Neuroscience 9 (Suppl 1), p. 37.
     [pdf] [link]

  • Jurjut O.F., Nikolic D., Singer W., Metzler D., Muresan R.C. (2008), Multidimensional Patterns of Neuronal Activity: How do we see them?, (CNS Meeting 08) Portland (Oregon), USA: BMC Neuroscience 9 (Suppl 1), p. 128.
     [pdf] [link]

  • Jurjut O.F., Nikolic D., Singer W., Metzler D., Muresan R.C. (2008), Exploring Parallelly Recorded Spike Trains, (Cosyne 08) Salt Lake City, USA, I-33.
    [pdf]

  • Muresan R.C. (2007), Do I integrate or do I resonate? That is the question! Coherent Behavior in Neural Networks (CoBeNN) Mallorca, Spain, P23.
     [pdf]

  • Jurjut O.F., Nikolic D., Metzler D., Singer W., Muresan R.C. (2007), Vizualizing Multi-dimensional Neuronal Data, Coherent Behavior in Neuronal Networks (CoBeNN) Mallorca, Spain, P16.