The role of neural oscillations in attention: Perspectives for computational models

Riding the slow wave: Exploring the role of entrained low-frequency oscillations in memory formation

Neural oscillations are proposed to support a variety of behaviors, including long-term memory, yet their functional significance remains an active area of research. Here, we explore a potential functional role of low-frequency cortical oscillations in episodic memory formation. Recent theories suggest that low-frequency oscillations orchestrate rhythmic attentional sampling of the environment by dynamically modulating neural excitability across time. When these oscillations entrain to low-frequency rhythms present in the environment, such as speech or music, the brain can build temporal predictions about the onset of relevant events so that these events can be more efficiently processed. Building upon this literature, we propose that entrained low-frequency oscillations may similarly influence the temporal dynamics of episodic memory by rhythmically modulating encoding across time (mnemonic sampling). Central to this proposal is the phenomenon of cross-frequency phase-amplitude coupling, whereby the amplitudes of faster (higher frequency) rhythms, such as gamma oscillations, couple to the phase of slower (lower-frequency) rhythms entrained to environmental stimuli. By imposing temporal structure on higher-frequency oscillatory activity previously linked to memory formation, entrained low-frequency oscillations could dynamically orchestrate memory formation and optimize encoding at specific moments in time. We discuss prior experimental and theoretical work relevant to this proposal.

PERIODIC ADAPTIVE ACTIVATION OF BEHAVIORS IN ROBOTIC SYSTEMS

The main goal of our current research is the design of a robotic architecture that has the capability of adapting the robot's behavior to the rate of change of a dynamic environment. We present a model which takes free inspiration from some features of biological clocks. In particular, we associate the concept of Innate Releasing Mechanisms (IRM) to the concept of periodic behavior activation in order to link the variability of the behavior to the circumstances in which it is activated. We propose an architecture in which the frequency of access to the sensory system is modified in accordance to the environmental changes. To this purpose we use the Schema Theory paradigm. Some first experimental results are reported and discussed.