The cognitive abilities of man and his extensive memorizing capabilities are assumed to rely on cortical processing. It has been accepted that the most relevant parameters for describing and understanding cortical function are the spatio-temporal patterns of activity. In this chapter it is presented that such patterns can be recorded in the cortex of behaving monkeys. It is shown that they span hundreds of milliseconds and maintain accuracy of a few milliseconds. The properties of these patterns suggest the nature of the neural circuitry that generates them, and therefore the mechanism that underlies cortical processing. By way of simulations the chapter explores how such circuits produce periodic, and non-periodic oscillations, and how activities in such circuits at different cortical regions can bind together to form compound entities. Anatomy, physiology, experimental results, and simulations lead to the conclusion that accurate spatio-temporal firing patterns are a significant aspect of information processing in the cortex, and that these patterns are generated by reverberations in syn-fire chains. Syn-fire chains are also sensitive to the time structure of incoming information. Thus, syn-fire reverberations in different brain regions can enhance or interfere with each other according to the compatibility of the sequences of activation in the chains. These properties may serve as the neuronal substrate for the compositionality of language.
Bibliographical noteFunding Information:
The authors are indebted to E. Ahissar and I. Nelken who helped in developing the experimental setup, to I. Haalman, E. Margalit, and H. Slovin who helped in carrying out the experiments, and to V. Sharkansky for help in the artwork. This research was supported in part by grants from the United-States Israeli Binational Science Foundation (BSF) and the Basic Research Fund administered by the Israel Academy of Sciences and Humanities.