Semantic memory: Complexity or connectivity?

Neural complexity and structural connectivity.

Tononi [Proc. Natl. Acad. Sci. U.S.A. 91, 5033 (1994)] proposed a measure of neural complexity based on mutual information between complementary subsystems of a given neural network, which has attracted much interest in the neuroscience community and beyond. We develop an approximation of the measure for a popular Gaussian model which, applied to a continuous-time process, elucidates the relati...

The Complexity of Graph Connectivity

In this paper we survey the major developments in understanding the complexity of the graph connectivity problem in several computational models, and highlight some challenging open problems.

Semantic Memory

Measuring semantic complexity

We define semantic comple=ity using a new concept of mesni~g automata. We measure the semantic complexity of understanding of prepositional phrases, of aa "in depth understanding system", and ofa :natural language interface to an on-line calendar. We argue that it is possible to measure some semantic complexities of-natural langu~e processin8 systems before building them, and that.systems:that ...

Topographic amnesia: spatial memory disorder, perceptual dysfunction, or category specific semantic memory impairment?

A 60 year old patient, SE, who presented with a severe difficulty in finding his way around previously familiar environments and a mild prosopagnosia is described. SE had herpes simplex encephalitis resulting in selective right temporal lobe damage. He showed normal spatial learning, but was severely imparied in his ability to recognise pictures of buildings and landmarks. The disorder was not ...