Experts from the University of Leicester have released research that breaks
with the past fifty years of neuroscientific opinion, arguing that the way
we store memories is key to making human intelligence superior to that of
animals.
It has previously been thought and copiously published 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, so that
memories don't get mixed up.
Now, after fifteen years of research, 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. The consequences of this are far reaching, as such neuronal
representation, devoid of specific contextual details, explains the abstract
thinking that characterizes human intelligence.
Leicester University's Director of Systems Neuroscience Professor Rodrigo
Quian Quiroga explains,
"In contrast to what everybody expects, when recording the activity of
individual neurons we have found that there is an alternative model to
pattern separation storing our memories.
"Pattern separation is a basic principle of neuronal coding that precludes
memory interference in the hippocampus. Its existence is supported by
numerous theoretical, computational and experimental findings in different
animal species but these findings have never been directly replicated in
humans. Previous human studies have been mostly obtained using Functional
Magnetic Resource Imagining (fMRI), which doesn't allow recording the
activity of individual neurons. Shockingly, when we directly recorded the
activity of individual neurons, we found something completely different to
what has been described in other animals. This could well be a cornerstone
of human's intelligence."
The study, 'No pattern sepaeration in the human hippocampus', argues that
the lack of pattern separation in memory coding is a key difference compared
to other species, which has profound implications that could explain
cognitive abilities uniquely developed in humans, such as our power of
generalization and of creative thought.
Professor Quian Quiroga believes we should go beyond behavioural comparisons
between humans and animals and seek for more mechanistic insights, asking
what in our brain gives rise to human's unique and vast repertoire of
cognitive functions. In particular, he argues that brain size or number of
neurons cannot solely explain the difference, since there is, for example, a
comparable number and type of neurons in the chimp and the human brain, and
both species have more or less the same anatomical structures. Therefore,
our neurons, or at least some of them, must be doing something completely
different, and one such difference is given by how they store our memories.
Reference:
Quiroga RQ. No Pattern Separation in the Human Hippocampus. Trends in
Cognitive Sciences. 2020;0(0). doi:
10.1016/j.tics.2020.09.012