53 research outputs found
Space as an invention of biological organisms
The question of the nature of space around us has occupied thinkers since the
dawn of humanity, with scientists and philosophers today implicitly assuming
that space is something that exists objectively. Here we show that this does
not have to be the case: the notion of space could emerge when biological
organisms seek an economic representation of their sensorimotor flow. The
emergence of spatial notions does not necessitate the existence of real
physical space, but only requires the presence of sensorimotor invariants
called `compensable' sensory changes. We show mathematically and then in
simulations that na\"ive agents making no assumptions about the existence of
space are able to learn these invariants and to build the abstract notion that
physicists call rigid displacement, which is independent of what is being
displaced. Rigid displacements may underly perception of space as an unchanging
medium within which objects are described by their relative positions. Our
findings suggest that the question of the nature of space, currently exclusive
to philosophy and physics, should also be addressed from the standpoint of
neuroscience and artificial intelligence
Induced current in the presence of magnetic flux tube of small radius
The induced current density, corresponding to the massless Dirac equation in
(2+1) dimensions in a magnetic flux tube of small radius is considered. This
problem is important for graphene. In the case, when an electron can not
penetrate the region of nonzero magnetic field, this current is the odd
periodical function of the magnetic flux. If the region inside the magnetic
tube is not forbidden for penetration of electron, the induced current is not a
periodical function of the magnetic flux. However in the limit , where
is the radius of magnetic flux tube, this function has the universal form
which is independent of the magnetic field distribution inside the magnetic
tube at fixed value of the magnetic flux.Comment: 5 pages, 1 figur
Learning agent's spatial configuration from sensorimotor invariants
The design of robotic systems is largely dictated by our purely human
intuition about how we perceive the world. This intuition has been proven
incorrect with regard to a number of critical issues, such as visual change
blindness. In order to develop truly autonomous robots, we must step away from
this intuition and let robotic agents develop their own way of perceiving. The
robot should start from scratch and gradually develop perceptual notions, under
no prior assumptions, exclusively by looking into its sensorimotor experience
and identifying repetitive patterns and invariants. One of the most fundamental
perceptual notions, space, cannot be an exception to this requirement. In this
paper we look into the prerequisites for the emergence of simplified spatial
notions on the basis of a robot's sensorimotor flow. We show that the notion of
space as environment-independent cannot be deduced solely from exteroceptive
information, which is highly variable and is mainly determined by the contents
of the environment. The environment-independent definition of space can be
approached by looking into the functions that link the motor commands to
changes in exteroceptive inputs. In a sufficiently rich environment, the
kernels of these functions correspond uniquely to the spatial configuration of
the agent's exteroceptors. We simulate a redundant robotic arm with a retina
installed at its end-point and show how this agent can learn the configuration
space of its retina. The resulting manifold has the topology of the Cartesian
product of a plane and a circle, and corresponds to the planar position and
orientation of the retina.Comment: 26 pages, 5 images, published in Robotics and Autonomous System
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