Examining the Characteristics of Episodic Memory using Event-related Potentials in Patients with Alzheimer's Disease

Summary

The methodology for collecting high-density event-related potential data while patients with Alzheimer's disease perform a recognition memory task is reviewed. This protocol will include subject preparation, quality assurance, data acquisition, and data analysis.

Abstract

Our laboratory uses event-related EEG potentials (ERPs) to understand and support behavioral investigations of episodic memory in patients with amnestic mild cognitive impairment (aMCI) and Alzheimer's disease (AD). Whereas behavioral data inform us about the patients' performance, ERPs allow us to record discrete changes in brain activity. Further, ERPs can give us insight into the onset, duration, and interaction of independent cognitive processes associated with memory retrieval. In patient populations, these types of studies are used to examine which aspects of memory are impaired and which remain relatively intact compared to a control population. The methodology for collecting ERP data from a vulnerable patient population while these participants perform a recognition memory task is reviewed. This protocol includes participant preparation, quality assurance, data acquisition, and data analysis. In addition to basic setup and acquisition, we will also demonstrate localization techniques to obtain greater spatial resolution and source localization using high-density (128 channel) electrode arrays.

Protocol

1. Set up the EEG Equipment

1. Our laboratory uses the 128-channel BioSemi ActiveTwo EEG acquisition system with "active" electrodes (Amsterdam, The Netherlands; http://www.biosemi.com) and the ActiveTwo electrode cap (Behavioral Brain Sciences Center, Birmingham, UK) to obtain ERP data.
2. Make sure that the battery is fully charged and attached to the amplifier.
3. Gather all materials necessary to complete participant set-up, including: syringe, gel, tape measure, various sized EEG caps, alcohol swabs, facial electrode stickers, and velcro straps to secure the electrode cables.
4. Place stickers on ....

Discussion

ERPs and behavioral data can provide us with different and complementary information. Whereas behavioral data informs us about the patients' performance, ERPs allow us to record discrete changes in brain activity. Due to their excellent temporal resolution, ERPs have proven very useful in dissociating and understanding the role of memorial processes (e.g., conceptual processing and familiarity, recollection, post-retrieval monitoring processes) that have been previously associated with specific old/new components of th.......

Materials

List of materials used in this article

Name	Company	Catalog Number	Comments
BioSemi Active Two EEG Acquisition System*	Cortech Solutions, Inc.
Polhemus Patriot Digitizer	Cortech Solutions, Inc.
E-Prime 2.0 Professional Software	Psychology Software Tools, Inc.
* This system includes the amplifier, Active Two EEG caps, syringes, SignaGel (conductive gel), and facial electrode stickers.