The idea that the electrical signal patterns generated by neurons represent the encoding of different types of cognitive information appears to be wrong, according to scientists at the Weizmann Institute. Their research, appearing in the journal Neuron, showed that the communication signals between neurons, as measured by the experimenters, were indistinguishable from random neuronal firings. Weizmann’s Dr. Ilan Lampl said the results called into question one of the key tenets used to explain how the brain works.
It had been believed that the central nervous system relied on specific patterns in neuronal electrical signals to encode different types of cognitive information. For example, in comparing objects like a table and a chair, the brain would discriminate between the different objects because each object would generate a distinct sequence of patterns within the neural system that the brain then interprets. Reinforcement of relationships between different objects and their associated signals occurred upon repeated presentation of that object, so that its pattern would be reproduced in a precise manner.
Experimental evidence supporting the pattern theory had been found in the past, but when Lampl recorded the activity of neurons in the cortex of anaesthetized rats and analyzed the data, he found no difference in the number of patterns produced or the time it takes for various patterns to repeat themselves. In fact, Lampl says, the recorded data was no different to data that was randomized.