Past events

Traditional models of memory dissociate memory from processes. Such tendency is rooted in the analogy between computers’ architecture and the brain, which dissociate the central processing units from the memory units. Based on such conceptualization, many empirical studies focus on simple delay periods in which memory has to be actively maintained but not processed and cases in which the integration between past and present information is undesirable. However, such models are not applicable to the majority of real life processes in which the past and present converge continuously in the processes of incoming information. Based on empirical data we outline a new framework for process-memory that resists the tendency to separate memory from process. We argue that cortical areas, ranging from early sensory areas to high order areas, has the capacity to accumulate information over time. Memory is intrinsic to each and any neural circuit, and is essential for its ability to process information. Furthermore, our data suggest that the process-memory timescale increases from early sensory areas to high order areas. Our hypothesis, that each brain area accumulates information over its preferred timescale, suggests that memories of the recent past are not stored in a few localized working memory buffers, but rather are distributed in an organized hierarchical topography throughout the nervous system. The “work of memory” is performed in virtually every neural circuit, and attentional systems modulate this ongoing processing in accordance with rule- or goal-related constraints.

One hundred sixty years after its discovery, the molecular mechanism of general anesthesia remains a notable mystery. A very wide range of agents ranging from the element xenon to steroids can act as general anesthetics on all animals from protozoa to man, suggesting that a basic cellular mechanism is involved. Electron spin resonance measurements show that volatile general anesthetics cause large changes in electron spin content of Drosophila fruit flies and that the spin responses are different in anesthesia-resistant mutants. These observations are consistent with the idea that general anesthetics perturb electron currents in cells. Electronic structure calculations on anesthetic–protein interactions are consistent with this mechanism and account for hitherto unexplained features of general anesthetic pharmacology.

Neurons continuously modulate their activity in time and magnitude; it is unclear how the dynamics of activity is related to brain computations and to behavior. In the first part of my talk I will show how we link between the dynamics of activity and the computation in the cerebellum-brainstem circuitry that generates eye movement. We found that dynamics of responses of neurons support a hierarchical organization of a neural integrator. In the second part of my talk I will show how we use the smooth pursuit eye movement to continuously readout the decision process. I will present a new framework for studying the neural mechanisms for decisions.