The role of rhythmicity of oscillations in cognition

Cognition and behaviour are believed to emerge from widespread, often transient, neuronal interactions in the brain. Some of these interactions are captured in the oscillatory activity present in EEG and MEG measurements. The phase-angle of these oscillations has been suggested to reflect the transient inhibitory and excitatory state of the underlying networks producing them. Furthermore, neuronal communication between networks has been suggested to be subserved by the phase-coupling of oscillations in sending and receiving regions. Using this framework, the first part of my talk will focus on new evidence that the disruption in the rhythmicity of an oscillation through external neuro-modulation such as deep-brain stimulation could lead to a reduction in pathological network ‘over-connectivity’ and translate to therapeutic improvements in disorders such as Parkinson’s and treatment of refractory obsessive compulsive disorder. The second part of my talk will focus on whether the phase of ongoing oscillations could be modulated by endogenous factors such as temporal expectation. Here, in contradiction to some current published findings I will be providing evidence that while the speed of oscillatory has a biasing effect on time perception, the phase of alpha activity cannot be modulated by top-down temporal expectation.