Temporal distributed processing-TDP: no wait-states in sensory pathways-a time-based approach of cortical function

A time-based concept of temporal distributed processing (TDP) across subcortical and cortical substrates is presented that accounts for dynamic aspects of cortical processing such as time-dependent receptive fields (RFs). It is based on experimental data about latency differences observed within different hierarchically organized areas. The high percentage of simultaneously activated neurons makes it rather unlikely that proceeding stages wait until the end of the processing of a previous one. This lack of wait-states is the key feature for the development of the TDP-scheme that incorporates the contributions of feedforward, lateral interactions (excitation and inhibition) and feedback. Possible impacts for routing back memory-based information to early processing stages are discussed as well as implications for multilayer models of brain functions or technical applications of sequential processing.