By Emma William | Contributor
New research from a study by the University of Leicester, published in the Trends in Cognitive Science journal, has contradicted fifty years worth of neuroscientific opinion, arguing that the way we store memories is key to human’s superior intelligence.
It was previously believed that it is ‘pattern separation in the hippocampus, an area of the brain critical for memory, that enables memories to be stored by separate groups of neurons, meaning that memories don’t get mixed up.
However, after fifteen years of research on the topic, Leicester University’s Director of Systems Neuroscience believes that in fact the opposite to pattern separation is present in the human hippocampus. He argues that, contrary to what has been described in animals, the same group of neurons store all memories. This breakthrough scientific discovery means that neuronal representation explains the abstract thinking that identifies human intelligence.
For instance, if you see a black cat on your way to work one evening, your brain will store the experience separately to any previous memories of seeing the cat on the same street – differentiating the memories.
A portion of studies which support pattern separation are single-neuron recordings on animals, such as rats and monkeys, which are then transferred to humans because we have similar brain structures. There have also been in depth experiments on human subjects and monitoring brain activity with Functional Magnetic Resource Imaging (fMRI).
Arguing against the use of fMRI, Professor Rodrigo Quian Quiroga, Director of Systems Neuroscience at Leicester University, contended that the technology “doesn’t allow recording the activity of individual neurons.” Speaking on the activity of individual neurons, the professor added that the researchers identified “something completely different to what has been described in other animals.” He then explained that, contrary to pattern separation, “evidence from human single-neuron recordings shows that episodic memories are coded by context-independent and invariant engrams in the human hippocampus.”
The studies experimented on single neurons in human brains revealed that episodic memory (the recall of life experiences) may not be dependent on the context, as it was initially believed. In addition, there may actually be a co-activation of neurons not previously considered to be involved occurring within this process.
Consequently, this discovery could have an immense impact on the world of neurology. As Professor Rodrigo Quian Quiroga – the current lead scientist on this project concerning memory formation in the human medial temporal lobe – suggests, this research “prompts us to reconsider the view of episodic memory as mental time travel, and the distinction between episodic and semantic memory.”
So instead of defining episodic memory as memory of personal life experiences and semantic memory as general knowledge, the scientific community may redefine and reinvestigate, considering overlaps between the two types of memory.
Moreover, it may lay the foundations for explaining why human intelligence is so different to that of chimps, despite the similarities in anatomical structures and numbers of neurons. The professor argues this reflects the thesis that human neurons must be doing something differently to chimpanzees in order to create such a wildly different level of intelligence.
This scientific breakthrough is a major success for the neuroscientific community and exhibits the way that science is constantly being considered and improved upon. Homosapiens are the dominant species due to this neuronal variation, explaining why we have an intelligence that other species could not even dream of (they lack the cognitive capabilities.) It will be interesting to see what future evidence this research project produces and what other scientifically accepted explanations are disproved.