Simon Thorpe

Research Interests

My current interests are centered on understanding the phenomenal processing speed achieved by the visual system. For a number of years we have been running experiments that attempt to measure just how fast visual processing is using briefly flashed natural scenes using a combination of electrophysiological and behavioural methods. With Holle Kirchner, we recently found that when two images are simultaneously flashed to the left and right of the fixation point, humans can initiate saccades to the side where the scene contains an animal in only 130 ms. Such severe temporal constraints pose major problems for virtually all current theories of visual processing. In an attempt to explain this sort of ultra-rapid processing I proposed a novel coding scheme that uses the order in which cells fire spikes, rather than firing rates to encode information. It turns out that using such a code may allow us recognise objects when as few as 1% of the neurons in the visual pathways have fired a spike. In 1999, I setup a company (SpikeNet Technology) that has developed image processing software based on these principles. A demo of the software can be downloaded from the company web site (www.spikenet-technology.com).
I have recently become interested in questions of the economy and tax reform. You can find out more about my radical ideas here.

Techniques Used

I’m currently using mainly behavioural and ERP methods for the experimental work and computer simulation for the modelling. But in the past I have used a wide range of techniques including single unitrecording in awake monkeys and fMRI in humans.

Teaching

I regularly teach for the M2 Neurosciences, Cognition & Comportement and for the M2 Neuropsychology. I have also done teaching for various image processing courses.

Research Group

• Danae Rémon – PhD student

Previous Doctoral Students

• Paul Ferré
• Christelle Larzabal
• Jaya Viswanathan
• Nadège Bacon-Macé
• Olivier Bichler
• Adrien Brilhault
• Sébastien Crouzet
• Arnaud Delorme (co-direction with Michèle Fabre-Thorpe)
• Florian Dramas (with Christophe Jouffrais)
• Denis Fize
• Jacques Gautrais
• Rudy Guyonneau
• Tim Masquelier
• Laurent Perrinet (co-direction with Manuel Samuelides)
• Corinne Roumes
• Rufin Van Rullen

Collaborations

My main collaborations within the lab are with Michèle Fabre-Thorpe, Leila Reddy, Emmanuel Barbeau, Florence Rémy and Alexandra Severac-Caquil. Outside the lab, I have close contacts with Daniel Pressnitzer and Yves Fregnac in Paris, Guillaume Masson in Marseille, Karl Gegenfurtner and Heiko Neumann in Germany, and Gustavo Deco in Spain.Selected publications

Selected publications

(complete publications list here)
⦁ Suied, C., Agus, T. R., Thorpe, S. J., Mesgarani, N., & Pressnitzer, D. (2014) Auditory gist : recognition of very short sounds from timbre cues.. The Journal of the Acoustical Society of America 135 (3) 1380-1391
⦁ Roclin, D., Bichler, O., Gamrat, C., Thorpe, S., & Klein, J. (2013) Design study of efficient Digital Order Based STDP Neuron implementations for extracting temporal features. International Joint Conference on Neural Networks ()
⦁ Suied, C., T. R. Agus, S. J. Thorpe and D. Pressnitzer (2013) Processing of Short Auditory Stimuli : The Rapid Audio Sequential Presentation Paradigm (RASP). Advances in Experimental Medicine and Biology 787 443-451
⦁ Thorpe, S. J. (2012) Spike-based Image Processing : Can we reproduce biological vision in hardware. Lecture Notes in Computer Science 7583 516-521
⦁ Agus, T., C. Suied, S. J. Thorpe and D. Pressnitzer (2012) Fast recognition of musical sounds based on timbre. Journal of the Acoustical Society of America 131 (5) 4124-4133
⦁ Bichler, O., D. Querlioz, S. J. Thorpe, J. P. Bourgoin and C. Gamrat (2012) Extraction of temporally correlated features from dynamic vision sensors with spike-timing-dependent plasticity. Neural Networks 32 339-348
⦁ Chanceaux, M., F. Vitu, L. Bendahman, S. J. Thorpe and J. Grainger (2012) Word processing speed in peripheral vision measured with a saccadic choice task. Vision Res 56C 10-19
⦁ Crouzet, S. M., O. Joubert, S.J. Thorpe and M. Fabre-Thorpe (2012) Animal detection precedes access to scene category. PLoS ONE 7 (12) e51471
⦁ Crouzet, S. M. and S. J. Thorpe (2011) Low level cues and ultra-fast face detection. Front Psychol 2 342
⦁ Agus, T. R., C. Suied, S. J. Thorpe and D. Pressnitzer (2010) Characteristics of human voice processing. IEEE International Symposium on Circuits and Syst 0 509-512
⦁ Agus, T., S. J. Thorpe and D. Pressnitzer (2010) Rapid formation of robust auditory memories : Insights from noise. Neuron 66 (4) 610-618
⦁ Crouzet, S. M., H. Kirchner and S. J. Thorpe (2010) Fast saccades towards faces : Face detection in just 100 ms. J Vis 10 (4) 16, 1-17
⦁ Kirchner, H., E. J. Barbeau, S. J. Thorpe, J. Regis and C. Liegeois-Chauvel (2009) Ultra-rapid sensory responses in the human frontal eye field region. J Neurosci 29 (23) 7599-606
⦁ Masquelier, T., E. Hugues, G. Deco and S. J. Thorpe (2009) Oscillations, phase-of-firing coding and STDP : an efficient learning scheme. J Neurosci 29 (43) 13484-13493
⦁ Masquelier, T., R. Guyonneau and S. J. Thorpe (2009) Competitive STDP-Based Spike Pattern Learning. Neural Comput 21 (5) 1259-1276
⦁ Masquelier, T., Guyonneau, R., & Thorpe, S. J. (2008). Spike timing dependent plasticity finds the start of repeating patterns in continuous spike trains. PLoS ONE, 3(1), e1377.
⦁ Masquelier T, Thorpe SJ. 2007. Unsupervised Learning of Visual Features through Spike Timing Dependent Plasticity. PLOS Computational Biology 3:e31
⦁ Kirchner H, Thorpe SJ. 2006. Ultra-rapid object detection with saccadic eye movements : Visual processing speed revisited. Vision Res 46:1762-76
⦁ Rousselet GA, Fabre-Thorpe M, Thorpe SJ. 2002. Parallel processing in high-level categorization of natural images. Nat Neurosci 5:629-30.
⦁ Thorpe S, Delorme A, VanRullen R. 2001. Spike-based strategies for rapid processing. Neural Netw 14:715-25.
⦁ VanRullen R, Thorpe SJ. 2001. The time course of visual processing : from early perception to decision- making. J Cogn Neurosci 13:454-61.
⦁ Thorpe S, Fize D, Marlot C. 1996. Speed of processing in the human visual system. Nature 381:520-2
⦁ Trotter Y, Celebrini S, Stricanne B, Thorpe S, Imbert M. 1992. Modulation of neural stereoscopic processing in primate area V1 by the viewing distance. Science 257:1279-81.
⦁ Fregnac Y, Shulz D, Thorpe S, Bienenstock E. 1988. A cellular analogue of visual cortical plasticity. Nature 333:367-70.
⦁ Thorpe SJ, Rolls ET, Maddison S. 1983. The orbitofrontal cortex : neuronal activity in the behavingmonkey. Exp Brain Res 49:93-115