What is epoching?
Epoching involves dividing continuous EEG data into smaller segments known as "epochs." Each epoch corresponds to a specific time interval of interest within the EEG recording. Epoching is a fundamental step that enables researchers to analyze brain activity in response to events, stimuli, or conditions.
Approaches to Epoching
- Time-Based Epoching: In time-based epoching, EEG data is divided into fixed time intervals, regardless of specific events or stimuli. Epochs are created by splitting the continuous EEG signal into equal-duration segments, often referred to as "time windows." This approach is useful when you're interested in studying general patterns of brain activity over time, without focusing on specific events or stimuli. Time-based epoching can help capture long-term trends, such as changes in brain activity during different phases of a task or recording session.
- Stimulation-Based Epoching: In simulation-based epoching, EEG data is segmented based on specific events or stimuli of interest. Epochs are defined around event markers that represent the occurrence of stimuli, tasks, or conditions. Each epoch captures the brain's response to a particular event, allowing researchers to analyze the neural processes associated with those events. Stimulation-based epoching is commonly used in event-related potential (ERP) studies, where researchers are interested in characterizing the brain's response to specific sensory, cognitive, or motor events.