In human scalp EEG recordings, both sustained potentials and alpha-band oscillations are present during the delay period of working memory tasks and may therefore reflect the representation of information in working memory. However, these signals may instead reflect support mechanisms rather than the actual contents of memory. In particular, alpha-band oscillations have been tightly tied to spa...

It is becoming increasingly apparent that brain oscillations in various frequency bands play important roles in perceptual and attentional processes. Understandably, most of the associated experimental evidence comes from human or animal electrophysiological studies, allowing direct access to the oscillatory activities. However, such periodicities in perception and attention should, in theory, ...

For a long time alpha oscillations have been functionally linked to the processing of visual information. Here we propose an new theory about the functional meaning of alpha. The central idea is that synchronized alpha reflects a basic processing mode that controls access to information stored in a complex long-term memory system, which we term knowledge system in order to emphasize that it com...

A common finding across many reaction time tasks is that people slow down on trials following errors, a phenomenon known as post-error slowing. In the present study, we tested a novel hypothesis about the neural mechanism underlying post-error slowing. Recent research has shown that when task-relevant stimuli occur in a rhythmic stream, neuronal oscillations entrain to the task structure, there...

Event-related alpha (10 Hz) oscillations in the EEG were measured in cats by means of intracranial electrodes. Simultaneous recordings were made from auditory and visual cortex while auditory and visual stimuli were applied (in separate sessions). Frequency domain analysis of the EEG responses showed marked alpha components only for adequate stimulation (e.g. visual cortex-visual stimulus). Thi...

Objective: Electrophysiological studies have identified abnormal oscillatory activities in the cerebral cortex in schizophrenia and mood disorders. Biological and pathophysiological evidence suggests specific deficits in serotonin (5-HT) receptor function in schizoaffective disorder (SA), a clinical syndrome with characteristics of both schizophrenia and bipolar disorder. This study investigate...

Recent work reported the observation of alpha frequency oscillations (8-12 Hz) in several regions of macaque visual cortex, including V2, V4, and inferotemporal cortex (IT). While alpha-related physiology in V2 and V4 appears consistent with a role in attention-related suppression, in IT, alpha reactivity appears conflicted with such a role. We addressed this issue directly by analyzing laminar...

The central problem for cognitive neuroscience is to describe how cognitive processes arise from brain processes. This review summarizes the recent evidence that synchronous neural oscillations reveal much about the origin and nature of cognitive processes such as memory, attention and consciousness. Memory processes are most closely related to theta and gamma rhythms, whereas attention seems c...

Brain oscillations in various frequency bands have been shown to be an important means of enabling interarea communication for high-level cognitive performance. Interestingly, perturbation to such oscillations in the form of weak noise has been shown to benefit perception in tasks such as the attentional blink (AB). Here, we investigated perturbation intrinsic to the AB task in two conditions i...

Neural oscillations in the alpha band (7-13 Hz) are commonly associated with disengagement of visual attention. However, recent studies have also associated alpha with processes of attentional control and stability. We addressed this issue in previous experiments by delivering transcranial alternating current stimulation at 10 Hz over posterior cortex during visual tasks (alpha tACS). As this s...