Dr. Georgios A. Keliris

Dr. Georgios A. Keliris

Project Leader
Alumni Department Physiology of Cognitive Processes
+49 7071 601 695
+49 7071 601 652
252

Main Focus

Neural circuits subserving visual perception

Vision is the sense that dominates the way we perceive our external world. Each moment, the visual system is challenged with processing immense amounts of information entering the eyes with only a small fraction reaching our awareness. What are the neural circuits responsible for the selection which leads to our visual experience? Finding the neural correlates of perception is not an easy endeavor. The difficulty stems from the fact that a perceptual event is almost always coupled with sensory stimulus changes, setting unclear whether the neural responses are related to perception or simply a response of the sensory processing mechanisms. To this end, multi-stable stimuli can provide unique insights into perceptual selection mechanisms, as changes in perception are decoupled from changes in the stimulus which remains unchanged. My research focuses in finding the neural underpinnings of visual perception by using high density multi-electrode recordings and state of the art fMRI in human and non-human primates.

Selected Publications

A new method for estimating population receptive field topography in visual cortex.

S. Lee, A. Papanikolaou, N.K. Logothetis, S.M. Smirnakis & G.A. Keliris, NeuroImage, 81:144-157, 2013

Visual Cortex organization in a macaque monkey with macular degeneration

Y.Shao*, G.A. Keliris*, A. Papanikolaou, M.D. Fischer, D. Zobor, H.Jaegle, N.K. Logothetis, & S.M. Smirnakis, Eur J Neurosci, Aug 2013

Introduction to research topic – binocular rivalry: a gateway to studying consciousness.

A. Maier, T.I. Panagiotaropoulos, N. Tsuchiya & G.A. Keliris, Frontiers in Human Neuroscience, 6(263):1-3, 2012

Detailed functional and structural characterization of a macular lesion in a rhesus macaque.

M.D. Fischer, D. Zobor, G.A. Keliris, Y Shao , M.W. Seeliger, S. Haverkamp, H. Jägle, N.K. Logothetis & S.M. Smirnakis, Documenta Ophthalmologica, 125(3):179-194, 2012

The role of the primary visual cortex in perceptual suppression of salient visual stimuli.

G.A. Keliris, N.K. Logothetis & A.S. Tolias, Journal of Neuroscience, 30(37):12353-65, 2010

Decorrelated neuronal firing in cortical microcircuits.

A.S. Ecker, P. Berens, G.A. Keliris, M. Bethge, N.K. Logothetis & A.S. Tolias, Science, 327(5965):584-7, 2010

Feature selectivity of the gamma-band of the local field potential in primate primary visual cortex.

P. Berens, G.A. Keliris, A.S. Ecker, N.K. Logothetis & A.S. Tolias, Frontiers in Neuroscience, 2(2):199-207, 2008

Robust controlled functional MRI in alert monkeys at high magnetic field: effects of jaw and body movements

G.A. Keliris, A. Shmuel, S.-P. Ku, J. Pfeuffer, A. Oeltermann, S. Thomas & N.K. Logothetis, NeuroImage, 36(3):550-570, 2007

A binocular rivalry study of motion perception in the human brain.

K. Moutoussis, G.A. Keliris, Z. Kourtzi & N.K. Logothetis, Vision Research, 45(17):2231-43, 2005

Neurons in macaque area V4 acquire directional tuning after adaptation to motion stimuli.

A.S. Tolias, G.A. Keliris, S.M. Smirnakis & N.K. Logothetis, Nature Neuroscience, 8(5):591-593, 2005

Curriculum Vitae

Curriculum Vitae

Georgios A. Keliris, Ph.D.

Project Leader

Max Planck Institute for Biological Cybernetics

Physiology of Cognitive Processes

Spemannstrasse 38

Tübingen, 72076

Germany

Tel.: +49 7071 601-695

E-mail: georgios.keliris@tuebingen.mpg.de

Web:

Education

Ph.D. Neural and Behavioral Sciences, 2008

Max-Planck Institute for Biological Cybernetics

(Laboratory of Prof. Dr. Nikos K. Logothetis)

International Max Planck Research School,

University of Tübingen, Germany

M.Sc. Neural and Behavioral Sciences, 2003

International Max Planck Research School,

University of Tübingen, Germany

B.Sc. Physics, 2000

University of Cyprus

Thesis

Nov 2007 Ph.D. Thesis: “Investigating the Neural Correlates of Visual Perception” Supervisors: Prof. Dr. Nikos K. Logothetis, Dr. Andreas S. Tolias

Feb 2003 M.Sc. Thesis: “Evaluation of Single Unit Isolation: Tetrode Recordings in Awake Behaving Macaques” Supervisor: Dr. Andreas S. Tolias

June 2000 B.Sc. Thesis: “Strategies for the search of the HIGGS boson in the CMS experiment. Fission channel: Higgs to two photons.” (in Greek) Supervisor: Prof. Dr. Panos Razis

Awards and Distinctions

June 1998 “Early Academic Performance Award” for the best performance in the core subjects of the Degree in Physics, University of Cyprus

June 2000 “First Award” of the Faculty of Physics, University of Cyprus, for finishing 1st in the ranking of the Faculty

Jan 2001 – Oct 2001 Stipendium by the Max-Planck Gesellschaft

Oct 2001 – Oct 2002 Scholarship by the DAAD for further academic study and training

2002 – 2005 Scholarship by the Max-Planck Gesellschaft for Doctoral studies

2008 – 2009 Post-doctoral fellowship scholarship by the Max-Planck Gesellschaft

June 2009 – Nov 2012 Post-doctoral fellowship from the ERC FP7 (Plasticise project)

May 2010 – July 2015 Principal investigator in a project of the Bernstein center for computational neuroscience (BCCN) Tuebingen (funds 2 Ph.D. student plus additional travel expenses and publication fees)

Research Internships

Feb 2001 – Sep 2001 Program developing for optimal visualization of the brain data collected by MEG and fMRI

MEG Center, University of Tübingen

Dr. Christoph Braun, Dr. Nikolaus Weiskopf

Sep 2001 – Feb 2002 Human fMRI studies of the perceptual filling-in

Max Planck Institute for Biological Cybernetics

Dr. Stelios Smirnakis, Dr. Zoe Kourtzi

Feb 2002 – Aug 2002 Connectivity of networks derived from firing properties of simulated neurons

Gatsby Computational Neuroscience Unit, University College London

Prof. Dr. Peter Dayan

Aug 2002 – Feb 2003 Neural basis of decisions: fMRI studies in macaques

Max Planck Institute for Biological Cybernetics

Dr. Andreas S. Tolias

June 2012 – Aug 2012 The role of attention in center-surround interactions in the visual cortex

Brain Science Institute, RIKEN, Japan

Prof. Dr. Justin L. Gardner

Publications

Shao Y*Keliris GA*, Papanikolaou A, Fischer MD, Zobor D, Jaegle, H, Logothetis NK, Smirnakis SM (2013)

Visual cortex organization in a macaque monkey with macular degeneration

Eur J Neurosci 2013

Lee S, Papanikolaou A, Logothetis NK, Smirnakis SM, Keliris GA (2013)

A new method for estimating population receptive field topography in visual cortex

NeuroImage 2013; 81:144-157

Maier A, Panagiotaropoulos TI, Tsuchiya N, Keliris GA (2012)

Introduction to research topic - Binocular rivalry: a gateway to studying consciousness

Front Hum Neurosci 2012; 6(263):1-3

Fischer DM, Zobor D, Keliris GA, Shao Y, Seeliger MW, Haverkamp S, Jägle H, Logothetis NK, Smirnakis SM (2012)

Detailed functional and structural characterization of a macular lesion in a rhesus macaque.

Doc Ophthalmol. 125(3):179-194

Stoewer S, Goense J, Keliris GA, Bartels A, Logothetis NK, Duncan J, Sigala N (2012)

An analysis approach for high-field fMRI data from awake non-human primates.

PLoS One. 2012; 7(1)

Stoewer S, Goense J, Keliris GA, Bartels A, Logothetis NK, Duncan J, Sigala N (2011)

Realignment strategies for awake-monkey fMRI data.

Magn Reson Imaging. 2011; 29(10):1390-400

Keliris GA, Logothetis NK, Tolias AS (2010)

The role of the primary visual cortex in perceptual suppression of salient visual stimuli.

J Neurosci. 2010; 30(37):12353-65

Ecker AS, Berens P, Keliris GA, Bethge M, Logothetis NK, Tolias AS (2010)

Decorrelated neuronal firing in cortical microcircuits.

Science. 2010; 327(5965):584-7

Berens P, Keliris GA, Ecker AS, Logothetis NK, Tolias AS (2008)

Feature selectivity of the gamma-band of the local field potential in primate primary visual cortex.

Front Neurosci. 2008; 2(2):199-207

Berens P, Keliris GA, Ecker AS, Logothetis NK, Tolias AS (2008)

Comparing the feature selectivity of the gamma-band of the local field potential and the underlying spiking activity in primate visual cortex.

Front Syst Neurosci. 2008; 2:2

Tolias AS, Ecker AS, Siapas AG, Hoenselaar A, Keliris GA, Logothetis NK (2007)

Recording chronically from the same neurons in awake, behaving primates

J Neurophysiol. 2007; 98(6):3780-90

Keliris GA, Shmuel A, Ku SP, Pfeuffer J, Oeltermann A, Steudel T, Logothetis NK (2007)

Robust controlled functional MRI in alert monkeys at high magnetic field: effects of jaw and body movements. Neuroimage. 2007; 36(3):550-70

Pfeuffer J, Shmuel A, Keliris GA, Steudel T, Merkle H, Logothetis NK (2007)

Functional MR imaging in the awake monkey: effects of motion on dynamic off-resonance and processing strategies.

Magn Reson Imaging. 2007; 25(6):869-82

Tolias AS, Keliris GA, Smirnakis SM, Logothetis NK (2005)

Reply to "Motion processin in macaque V4"

Nat Neurosci. 2005; 8(9):1125

Moutoussis K, Keliris GA, Kourtzi Z, Logothetis NK (2005)

A binocular rivalry study of motion perception in the human brain.

Vision Res. 2005; 45(17):2231-43

Tolias AS, Keliris GA, Smirnakis SM, Logothetis NK (2005)

Neurons in macaque area V4 acquire directional tuning after adaptation to motion stimuli.

Nat Neurosci. 2005; 8(5):591-3

Book Chapters

Panagiotaropoulos TI, Logothetis NK, Keliris, GA (in press)

Neural approaches to perceptual organization.

The Handbook of Computational Perceptual Organization (Eds. Gepshtein-Maloney)

Editorials

Special Research Topic in Frontiers in Human Neuroscience

(co-hosted with A. Maier , T.I. Panagiotaropoulos, N. Tsuchiya)

Student supervision

May 2007 – Feb 2009

Master’s thesis: “Correlates of perception in primate primary visual cortex”) – now Ph.D. student with Prof. Dr Anthony Holtmaat at University of Geneva

Aug 2009 – Oct 2009 Kristin Herper

Lab rotation: “Binocular receptive field mapping after adaptation”

Feb 2011 – Apr 2011 Pooja Viswanathan

Lab rotation: “Spike-LFP phase locking across frequency bands under different task conditions” – now Ph.D. student at University of Tuebingen.

Nov 2011 – Aug 2012 J Kausik Lakshminarasimhan

Master’s thesis: “Neuronal gamma-band synchronization in macaque area V1 follows changes in firing rate during monocular stimulation”. – now Ph.D. student at Baylor College of Medicine, Houston, TX

Jun 2009 – to date (Ph.D. student ) - co-supervised with Prof. Stelios Smirnakis (Baylor)

Project title: “Visual cortical plasticity after V1 lesion and retina degeneration in macaque monkeys”

Sep 2009 – to date (Ph.D. student)

Project title: “The role of parietal visual cortex in perceptual transitions during bistable perception”

Nov 2009 – to date (Ph.D. student) - co-supervised with Prof. Smirnakis (Baylor)

Project title: “Visual cortex reorganization in human subjects with cortical lesions”

Feb 2010 – to date (Ph.D. student) – funded by DAAD

Project title: “Effects of attention on neural processing in the striate cortex on non-human primates: a simultaneous electrophysiology fMRI study”

Apr 2011 – to date (Ph.D. Student) – funded by

Project title: “Neuronal population activity underlying multi-stable motion perception”

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