What are ERPs?
  • ERPs are transient changes in the brainís electrical activity that occur in response to a discrete event (e.g., a brief presentation of a stimulus).

  • ERPs reflect the electrical activity of a group of neurons that fire in synchrony in response to a particular event.

  • Neurophysiological and biophysical findings strongly suggest that ERP waveforms are generally the reflection of dendritic or post-synaptic potentials rather than axonal action potentials

ERPs at Hampshire College
The ERP laboratory at Hampshire currently includes a SynAmps 32 channel amplifier system and two personal computers, one for stimulus display and behavioral response measurement, and another for data acquisition.

SynAmps is a software-programmable, optically isolated amplifier capable of true DC or AC recording. It is equipped with 28 monopolar and 4 bipolar channels, and was designed so that the first stage of amplification takes place in the head box, thereby reducing noise pickup. Impedance and calibration checking are built into the amplifier and data is transferred to the host computer via a high-speed SCSI connection.

The unit features ultra-low noise amplification and 16-bit analog-to-digital (A-to-D) conversion. A connector is available for electrode cap arrays. Data acquisition is controlled by SCAN, a commercially available software suite for electrophysiological data collection and analysis. SCAN incorporates an intuitive interface for off-line processing and statistics as well as a variety of off-line processing tools from baseline correction and digital filtering to principal components analysis and spatial filtering.