Rodrigo Quian Quiroga – EEG, ERP and single cell recordings database


Dataset # 1: Human single-cell recording

This example is a 30’ multiunit recording in the medial temporal lobe of an epileptic patient from Itzhak Fried’s lab at UCLA. Try wave_clus for spike detection and sorting of this data.

            Download file (74Mb .zip)


Dataset # 2: Simulated extracellular recordings

These simulated datasets are described in:

Unsupervised spike detection and sorting with wavelets and superparamagnetic clustering.

R. Quian Quiroga, Z. Nadasdy and Y. Ben-Shaul

Neural Computation 16, 1661-1687; 2004.


where they were used for testing the spike sorting algorithm. You should be able to reproduce the results of the paper and, eventually, compare wave_clus with other spike sorting algorithms.


Dataset # 3: EEG signals from rats

Each example contains 5 sec of a two-channel EEG recording at the left and right frontal cortex of male adult WAG/Rij rats. Signals were referenced to an electrode placed at the cerebelum, they were filtered between 1-100 Hz and digitized at 200 Hz. Example A correspond to a normal EEG and examples B, C, D and E contain spike-wave discharges.

We thank Giles van Luijtelaar and Joyce Welting for allowing their distribution.

Download files:   






Details on the recordings as well as on the physiological results can be obtained from:
The reticular thalamic nucleus is involved in left-right EEG synchronization.
van Luijtelaar ELJM, Welting J and Quian Quiroga R.
in: Sleep-Wake research in the Netherlands. A. van Bemmel et al. (eds.), Dutch Society for Sleep-Wake Research, 2000.

The first three datasets were analysed in the paper:
Performance of different synchronization measures in real data: a case study on electroencephalographic signals.
Quian Quiroga R, Kraskov A, Kreuz T and Grassberger P.
Phys. Rev. E, 2002; 65: 041903.

and the last two were also analyzed in:
Event synchronization: a simple a fast method to measure synchronicity and time delay patterns.
Quian Quiroga R. T. Kreuz and Grassberger P
Phys. Rev. E, in press.


Dataset # 4: Pattern visual evoked potentials.                          

Each file corresponds to the recording on a different subject in the left occipital electrode (O1), with linked earlobes reference. Each file contains several artifact-free trials, each of them containing 512 data points (256 pre- and 256 post-stimulation) stored with a sampling frequency of 250 Hz. Trials are stored consecutively in a 1 column file. Data was pre-filtered in the range 0.1-70Hz. All trials correspond to target stimulation with an oddball paradigm (see the papers for details).  

We thanks Martin Schuermann for allowing their distribution.

Download files:    


30 trials


16 trials

These files were used for showing a denoising implementation that helps to visualize single-trial evoked potentials in:
Obtaining single  trial EPs with wavelet denoising.
Quian Quiroga R.
Physica D, 145: 278-292 (2000) .

Moreover, we show a time-frequency analysis of evoked potentials using Wavelets in:

Functions and sources of evoked EEG alpha oscillations studied with the Wavelet Transform
R. Quian Quiroga and M Schürmann
Clin. Neurophysiol., 1999; 110: 643-654. 

and in:

Wavelet Transform in the analysis of the frequency composition of evoked potentials.
R. Quian Quiroga, O. Sakowicz, E. Basar and M. Schürmann.
Brain Research Protocols, 8: 16-24; 2001. Erratum: in fig.1, upsampling should precede convolution with G' and H'.

and we show the application of an entropy defined from the distribution of wavelet coefficients in:

Wavelet-entropy: a measure of order in evoked potentials.
R. Quian Quiroga, O Rosso and E Basar
Electr. Clin. Neurophysiol. (Suppl.), 1999; 49: 298-302. 

and in:

Wavelet entropy in event-related potentials: a new method shows frequency tuning of EEG-oscillations.
Quian Quiroga R, Rosso O, Schürmann M and Basar E.
Biological Cybernetics, 2001; 84: 291-299.

Dataset # 5: Tonic-clonic (Grand Mal) seizures.                          

These files show tonic-clonic seizures of two subjects recorded with a scalp rigth central (C4) electrode (linked earlobes reference). It contains a total of 3 minutes with about 1 min pre-seizure, the seizure and some post-seizure activity. Sampling rate is 102.4 Hz (see the papers for more details).

Download files:



A time-frequency analysis of these type of seizures was done in:

Searching for Hidden Information with Gabor Transform in Generalized Tonic-Clonic Seizures
Quian Quiroga R., Blanco S., Rosso O., Garcia H. and Rabinowicz A.
Electroenceph. and Clin. Neurophysiol., 1997; 103: 434-439.

and in:

Frequency evolution during tonic-clonic seizures.
Quian Quiroga R., Garcia H and Rabinowicz A
Electromyography and Clinical Neurophysiology, in press

Dataset # 6: Ongoing EEG activity.                          

Five data sets containing quasi-stationary, artifact-free EEG signals both in normal subjects and epileptic patients were put in the web by Ralph Andrzejak from the Epilepsy center in Bonn, Germany. Each data set contains 100 single channel EEG segments of 23.6 sec duration. The data can be downloaded from:

A study of non-linear determinism of this data has been published in Phys. Rev. E (follow the link from the previous address).

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