Effects of Connectivity on Narrative Temporal Processing in Structured Reservoir Computing

Abstract

Computational models of language are having an increasing impact in understanding the neural bases of language processing in humans. A recent model of cortical dynamics based on reservoir computing was able to account for temporal aspects of human narrative processing as revealed by fMRI. In this context the current research introduces a form of structured reservoir computing, where network dynamics are further constrained by the connectivity architecture in order to begin to explain large scale hierarchical network properties of human cortical activity during narrative comprehension. Cortical processing takes place at different time scales depending on the position in a hierarchy from posterior sensory input areas to higher level associative frontal cortical areas. This phenomena is likely related to the cortical connectivity architecture. Recent studies have identified heterogeneity in this posterior-anterior hierarchy, with certain frontal associative areas displaying a faster narrative integration response than much more posterior areas. We hypothesize that these discontinuities can be due to white matter connectivity that would create shortcuts from fast sensory areas to distant frontal areas. To test this hypothesis, we analysed the white matter connectivity of these areas and discovered clear connectivity patterns in accord with our hypotheses. Based on these observations we performed simulations using reservoir networks with connectivity patterns structured with an exponential distance rule, yielding the sensory-associative hierarchy. We then introduce connectivity short-cuts corresponding to those observed in human anatomy, resulting in frontal areas with unusually fast narrative processing. Using structured reservoir computing we confirmed the hypothesis that topographic position in a cortical hierarchy can be dominated by long distance connections that can bring frontal areas closer to the sensory periphery.

Safety in Numbers or Lost in the Crowd? Litigation of Mass Claims and Access to Justice in Ontario

“…111 Recently, the Court of King's Bench refused to certify a class proceeding involving sexual abuse by a chaplain at a youth correctional facility because many of the proposed common issues were not workable, being "directly tied to, and dependent upon, the determination of individual issues … [they] will not advance the litigation and can be counter productive." 112 In addition, the certification stage and the conduct of a common issues trial would result in significant delay in the final resolution of class members' claims. 113 Finally, where only a very small part of the liability picture is answered in the common issues trial, then aggregate damages will not be awarded at that stage.…”