CSHC - Center for the Study of Human Cognition

Event-related potentials (ERPs) are changes in electrical currents in response to stimuli and cognitive tasks. With ERPs brain activity can be measured at a very high temporal scale, e.g. by recoding eectric potentials thousand times a second. In contrast to measures of blood oxygenation with fMRI, ERPs are assumed to be direct reflections of neural activity, and are thus a powerful tool in the study of human cognition. The three parameters of ERP are the strength of the response (amplitude), the speed of the response (latency), and the localization of the response (scalp topography).

The ERP-lab at the Center for Studies of Human Cognition consists of 3 electrically-shielded recording chambers (Faraday cages). Each has state of the art equipment for the presentation of stimuli and recording or EEG (Electroencephalogram, which is the basis for deriving ERPs). A lot of time and effort has been spent optimizing the presentation and recording conditions, which are now superb (thanks to Trond Svendsen and his interns). For recording, we use different Neuroscan systems (www.neuroscan.com), and for stimulus presentation, we mainly use E-prime (www.pstnet.com) and Stim2, which is Neuroscan’s own presentation software.
Lab 1 is our most heavily used research lab, and is dedicated to high-density recordings with 128 channels. This system consists of two Neuroscan SynAmps2 linked 70 Channel amplifier system, each consisting of 64 monopolar, 4 bipolar and 2 high-level channels.
Lab 2 is has the same great system, with half the channels, consisting of one Neuroscan SynAmps2 70 Channel amplifier system.
Lab 3 has a 40 channel Neuroscan NuAmp system.
All labs can be used by all employees and students familiar with the equipment. Currently, several projects are run in the labs and both PhD and Master students do their thesis projects here. In addition, lab project courses at BA level are offered each term, with around 40 students running projects yearly.

For analysis of ERP data, we use a number of different softwares. NeuroScan’s software Scan is often used for preprocessing of data, in addition to custom made software. For source localization of high-density ERP data, dynamic Statistical Parametric Mapping (dSPM) developed by Dale, Fischl, Halgren et al. (2002, Neuron) is used, though a collaboration with among others Don Hagler at Dale and Halgren’s multi-modal neuroimaging lab at UCSD.

Through collaboration with Scott Makeig and Arnoldo Delorme at Schwartz Center for Computational Neuroscience, we also use EEG-lab (www.sccn.ucsd.edu/eeglab) for analyses of EEG data.