Event-related or evoked responses are generally considered to reflect transient, discrete processes associated with responses to external stimuli or internal imperatives. The time courses of many event-related response components look suggestively like the postsynaptic potentials that are recorded directly from neural tissue, perhaps reinforced by population activation and broadened by timing jitter. However, in some cases the response of neural populations appears to reflect a reorganization of ongoing activity; either an increase in synchronized oscillatory activity (event-related synchronization) or a decrease (event-related desynchroni-zation). Although most authors consider these to be distinct phenomena, others have argued that all event-related responses might reflect transient phase locking of spontaneous activity. For example, the waveforms associated with some auditory evoked responses look like a damped oscillation. Perhaps the most interesting responses of this class are transient oscillatory population responses that may reflect phase locking within a network. Such processes are not phase-locked with respect to the stimulus and appear to reflect detection or "binding" of features such as coherent motion or a shared contour that may extend well beyond the receptive field of any individual neuron.

Some other turtles eat leaves radios and various plant parts Turtles that live where the winters is cold bury themselves

Figure 10 ERP effects elicited during language processing. Average ERP data from written sentences read one word at a time for comprehension. Upper trace: An N400 elicited by semantic violation. Lower trace: P600 elicited by grammatical violation. (Figure courtesy of Kutas and Dale.)

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