Scientists have uncovered a mathematical link
between memory, senses, and intelligence, revealing
that seven may be the magic number. Credit:
AI/ScienceDaily.com
Researchers
at Skoltech have developed a mathematical model that
explores how memory functions. When they analyzed
this model, they discovered intriguing results that
could help improve robotic systems, artificial
intelligence, and our understanding of how the human
mind stores information. The findings, published in
Scientific Reports, suggest there might be
an ideal number of senses—and if that’s true, our
five senses might not be enough!
"Our
conclusion is of course highly speculative in
application to human senses, although you never
know: It could be that humans of the future would
evolve a sense of radiation or magnetic field. But
in any case, our findings may be of practical
importance for robotics and the theory of
artificial intelligence," said study co-author
Professor Nikolay Brilliantov of Skoltech AI. "It
appears that when each concept retained in memory
is characterized in terms of seven features—as
opposed to, say, five or eight—the number of
distinct objects held in memory is maximized."
Following a
research tradition that began in the early 20th
century, the team focused on modeling the basic
units of memory known as “engrams.” An engram can
be thought of as a sparse collection of neurons in
different brain regions that fire together. Each
engram represents a concept, described through a
set of features. For humans, these features
correspond to sensory experiences—for example, the
concept of a banana includes its appearance,
smell, taste, and other sensory qualities. In this
framework, the banana becomes a five-dimensional
object within a mental space containing all the
other memories stored in the brain.
Engrams evolve over time, becoming sharper or
more diffuse depending on how often they are
triggered by sensory input from the outside world.
This process represents how we learn and forget as
we interact with our environment.
"We have mathematically demonstrated that the
engrams in the conceptual space tend to evolve
toward a steady state, which means that after some
transient period, a 'mature' distribution of
engrams emerges, which then persists in time,"
Brilliantov commented. "As we consider the
ultimate capacity of a conceptual space of a given
number of dimensions, we somewhat surprisingly
find that the number of distinct engrams stored in
memory in the steady state is the greatest for a
concept space of seven dimensions. Hence the seven
senses claim."
In other
words, let the objects that exist out there in the
world be described by a finite number of features
corresponding to the dimensions of some conceptual
space. Suppose that we want to maximize the
capacity of the conceptual space expressed as the
number of distinct concepts associated with these
objects. The greater the capacity of the
conceptual space, the deeper the overall
understanding of the world. It turns out that the
maximum is attained when the dimension of the
conceptual space is seven. From this the
researchers conclude that seven is the optimal
number of senses.
According to
the researchers, this number does not depend on
the details of the model -- the properties of the
conceptual space and the stimuli providing the
sense impressions. The number seven appears to be
a robust and persistent feature of memory engrams
as such. One caveat is that multiple engrams of
differing sizes existing around a common center
are deemed to represent similar concepts and are
therefore treated as one when calculating memory
capacity.
The memory of humans and other living beings is
an enigmatic phenomenon tied to the property of
consciousness, among other things. Advancing the
theoretical models of memory will be instrumental
to gaining new insights into the human mind and
recreating humanlike memory in AI agents.![]()