The
purpose
of
this
review
is
to
present
information
from
different
experiments
that
supports
the
proposal
that
brain
systems
are
able
to
predict,
in
a
short-term
interval,
certain
characteristics
about
the
next
incoming
stimuli.
This
ability
allows
the
subject
to
be
ready
for
the
stimuli
and
be
more
efficient
in
completing
the
required
task.
Evidence
is
presented
from
different
sensory-motor
experiments,
such
as
the
central
cueing
Posner
paradigm;
Contingent
Negative
Variation
(E1-E2),
spectral
modulation
during expectancy and Lateralized Readiness
Potential
during
the
first-order
sequential
effect.
Some
cases
from
motor
experiments
are
also
presented,
such
as
express
saccades,
the
manual
gap
paradigm
and
ocular
smooth
pursuit
movements.
All
these
data
support
a
neurocognitive
model
that
can
be
related
to
neuroanatomical
structures
whose
connections
have
been
well-
established.
In
the
final
section,
a
possible
algorithm
that
explains
the
selection of a preparatory set among the alternatives is discussed