Brain regions and their dynamics in prospective memory retrieval: a MEG study.

We measured brain activity using magnetoencephalography in five participants during ongoing tasks that included prospective memory, retrospective memory, and oddball trials. Sources were identified in the hippocampal formation and posterior parietal and frontal lobes. Posterior parietal cortex activation had an earlier onset in the prospective memory condition than retrospective memory or oddball conditions, a higher level of theta activity in the retrospective condition, and higher levels of upper alpha in the prospective and oddball conditions.

MEG reveals different contributions of somatomotor cortex and cerebellum to simple reaction time after temporally structured cues.

Magnetoencephalography (MEG) was used to measure brain activity while participants performed a simple reaction to targets after either a random interval (uncued targets) or a series of isochronous warning stimuli with 200-ms intervals that acted as a countdown. Targets could arrive "on time" or "early" relative to the preceding warning stimuli. Cerebellar activity before any stimulus onset predicted uncued simple reaction time.

Chronometric evidence for entrained attention.

Recent theories of dynamic attention have renewed the interest in temporal context as a determinant of attention. The mechanism of dynamic attention remains unclear, and both stochastic time perception processes and deterministic oscillators are possible. The results of Experiment 1 demonstrate that attention can be guided by isochronous series of warning stimuli and that elapsed time cannot fully account for this effect.

Phase shift detection in thalamocortical oscillations using magnetoencephalography in humans.

Magnetoencephalography was used to investigate exogenously stimulated oscillatory activity between cortex and thalamus resulting from clicks presented binaurally at the rate of 40 Hz. Analysis of the responses demonstrated activation of left and right auditory cortex, medial parietal cortex, thalamus, and cerebellum. Cross-correlations of the source waveforms revealed synchronicity between the auditory cortex sources (r > 0.