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Abstract:
The presented model outlines how the learning of the serial
orderof motor activity is achieved, a question that is also
important for the study of articulation. It based on the
following two assumptions: (1) Actions and perceptions are
represented in a common domain (common coding principle, Prinz,
1997). (2) Actions are initiated by their effects or goals
(principle of effect control). The model does not explicitly
refer to verbal articulation, but we assume that the principles
we describe apply to speech as well. The two principles are
derived from the 'Theory of Event Coding' (TEC; Hommel et al.,
1998). Up to now, this theory lacks concrete statements about how
the action plans that are formed at the concept level are
transformed into motor activity. We will outline how this gap may
be filled. Following a model of Kuperstein (1991) we assume that
motor and sensory neuronal patterns are integrated in a
topographic map. In this way sensorimotor representations are
formed that do not represent an event (a perception or an action)
but the common occurrence of two events. They are acquired if
motor activation patterns repeatedly occur together with the same
sensory events (effects of the action) in the environment. A
similar idea for motor learning (simulating a babbling-phase) is
used in the model of speech production by Guenther (1995). To
answer the question of how an association of a motor pattern with
a subsequent sensory effect can be explained with a biologically
plausible learning rule, we have modified the learning
architecture from Aitken (1994). It explains the learning of a
motor sequence through the correlation of a motor pattern with
the simultaneous sensory effect of the motor pattern that
occurred immediately before the current one. To find a solution
to the problem of how a certain motor pattern can be connected
with its respective subsequent effect, we assume that the
sensorimotor code consists of an 'integration' of a motor
sequence that was learned in the way described by Aitken. The
code consists of a number of sensory effects and a motor sequence
that are all associated. Each sensory input that conforms to one
of the associated effects activates the whole code, that is, it
initiates the motor sequence. An overview of empirical evidence
for the model will be presented, focusing on perceptual-motor
interactions.
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