| Popis: |
This chapter discusses general aspects of evoked and event-related responses in MEG and EEG recordings. The earliest evoked responses occur within milliseconds from stimulus onset (for example in the auditory brainstem) and cortical responses continue for many hundreds of milliseconds poststimulus. Sustained potentials and fields can be recorded during long-duration stimuli, or during tasks involving motor planning, attention, and other cognitive operations. Interstimulus interval and physical stimulus characteristics can dramatically affect amplitudes and latencies of evoked responses. A distinction is made between transient and steady-state responses. Various nomenclatures adopted in literature for different types of evoked responses are discussed and recommendations are given for more consistency in nomenclature. |
