Helpful Definitions

Nonstationarity

Nonstationarity means that signal's statistical characteristics change with time. It can arise due to many reasons such as as eye movements, muscle artifacts, and changes in the subject's physiological state.

Variability

• Intersubject variability: variability occurring between subjects in an experiment.
• Intertrial and intersession variability: variability or changes in the measurements or outcomes obtained from multiple trials/sessions of an experiment or study.

Motor imagery

Motor imagery: neuronal activity that occurs when a subject voluntarily imagines making a movement without actually performing it, for example, imagination of the movement of the right hand.

Notch filter

Notch filter: a type of band-stop filter, which is a filter that attenuates frequencies within a specific range while passing all other frequencies unaltered.

Generalizable features

Generalizable features: characteristics or attributes of data that are transferable to new and unseen data. These features have the ability to accurately predict outcomes or patterns in new data based on the patterns learned from the original data.

Compact convolutional network

Compact convolutional network: artificial neural network architecture characterized by its compact structure, which reduces the number of parameters and computation required. CCN for EEG is trained on EEG data to recognize patterns and features relevant to specific mental states, activities, or diseases.

Neurorehabilitative BCI applications

• Neurorehabilitation is used to refer to the process by which the remaining/intact neural system regains the ability to perform a function.
• Rehabilitation of function through BCIs typically involves the use of neurofeedback with or without neural stimulation, with the goal of improving users’ capacities to communicate, interact with the environment, and achieve other personal goals.