Eliciting and Recording Event Related Potentials (ERPs) in Behaviourally Unresponsive Populations: A Retrospective Commentary on Critical Factors

Abstract

A consistent limitation when designing event-related potential paradigms and interpreting results is a lack of consideration of the multivariate factors that affect their elicitation and detection in behaviorally unresponsive individuals. This paper provides a retrospective commentary on three factors that influence the presence and morphology of long-latency event-related potentials—the P3b and N400. We analyze event-related potentials derived from electroencephalographic (EEG) data collected from small groups of healthy youth and healthy elderly to illustrate the effect of paradigm strength and subject age; we analyze ERPs collected from an individual with severe traumatic brain injury to illustrate the effect of stimulus presentation speed. Based on these critical factors, we support that: (1) the strongest paradigms should be used to elicit event-related potentials in unresponsive populations; (2) interpretation of event-related potential results should account for participant age; and (3) speed of stimulus presentation should be slower in unresponsive individuals. The application of these practices when eliciting and recording event-related potentials in unresponsive individuals will help to minimize result interpretation ambiguity, increase confidence in conclusions, and advance the understanding of the relationship between long-latency event-related potentials and states of consciousness.

Assessing Cognitive Outcomes in Coma Survivors: A Literature Review

“…First, we only included behavioral measures of cognition within the scope of this review. Event-related brain responses, such as event-related potentials (ERPs) have shown strong potential for detecting cognitive ability in the absence of behavioral responsiveness [21], such as in coma. Similarly, command-following detection through neuroimaging modalities such as functional magnetic resonance imaging (fMRI) have been used to indicate consciousness in behaviorally unresponsive individuals, but can also be considered indications of underlying cognitive ability [22].…”

Analyses of Subsample Averaging of Single Trials for Event-Related Potential Classification

“…Event-related potentials (ERPS), which are the brain responses to specific sensory, cognitive, or motor events [1][2][3][4], are widely used to diagnose neurological disorders in clinical evaluations [5][6][7][8][9][10][11] and to study brain functioning in neuroscience and cognitive psychology research [12][13][14][15][16][17][18][19]. The response to an event, referred to as a single trial, is modeled as the additive superposition of the ERP (signal of interest) and the ongoing electroencephalogram (EEG) activity (noise).…”