The way brain networks maintain high transmission efficiency is believed to be fundamental in understanding brain activity. Brains consisting of more cells render information transmission more reliable and robust to noise. On the other hand, processing information in larger networks requires additional energy. Recent studies suggest that it is complexity, connectivity, and function diversity, rather than just size and the number of neurons, that could favour the evolution of memory, learning, and higher cognition. In this paper, we use Shannon information theory to address transmission efficiency quantitatively. We describe neural networks as communication channels, and then we measure information as mutual information between stimuli and network responses. We employ a probabilistic neuron model based on the approach proposed by Levy and Baxter, which comprises essential qualitative information transfer mechanisms. In this paper, we overview and discuss our previous quantitative results regarding brain-inspired networks, addressing their qualitative consequences in the context of broader literature. It is shown that mutual information is often maximized in a very noisy environment e.g., where only one-third of all input spikes are allowed to pass through noisy synapses and farther into the network. Moreover, we show that inhibitory connections as well as properly displaced long-range connections often significantly improve transmission efficiency. A deep understanding of brain processes in terms of advanced mathematical science plays an important role in the explanation of the nature of brain efficiency. Our results confirm that basic brain components that appear during the evolution process arise to optimise transmission performance.
In 2007, an excavation was undertaken in the supposed place of deposit of the Roman hoard of denarii in the village of Podzamcze (central Poland). In the older literature, the find used to be located in nearby Maciejowice. Coins found in Podzamcze in recent years, and the analysis of the information obtained so far concerning this discovery, allow the assumption that it was Podzamcze where the hoard of denarii discovered in 1875 was found. During the excavation three denarii were recovered below the humus layer: one each of Hadrian, Marcus Aurelius and Commodus. On 9 February 2008, the researchers undertook field prospecting again using metal detectors in the area of excavations conducted before, which resulted in recovering a quarter of another denarius of Commodus. The region of the confluence of the Okrzejka and Vistula rivers is relatively abundant in sites from the period of Roman influence. Sites of the Przeworsk culture are represented here, as well as those of the Wielbark culture, which at stage B2/C1a expanded into west Mazovia. Within this small area we find settlements, burial grounds, and also single items, including Roman coins. The coins are represented mostly by denarii from the second century, typical of Poland. However we also find earlier coins here, i.e. from the first century with an undated Republican denarius, as well as later ones, dating from the third century, represented by a follis of Maximianus Herculius (c 296–297?). In the light of the finds made in this area, the region of the confluence of the Okrzejka and Vistula rivers appears as a rather important local settlement center, which was probably connected with the outside world through various kinds of contacts.