Neuromorphic Smart Controller for Seismically Excited Structures - Design Optimization of Active and Passive Structural Control Systems - page 220

Figure 2. Schematic of the brain emotional learning model

mizes the emotional punishment) under various
sets of sensory inputs that the dynamic system is
receiving. The sensory inputs are described as the
stimulus that the dynamic system is currently
experiencing. Also, the emotional signals reflect
the degree of satisfaction with the linkage between
the stimulus and reaction of the dynamic system
at the time. In the following section, the functions
of the BEL model components are briefly de-
scribed.

• Sensory Cortex: As seen in Figure 2, sen-

sory cortex receives sensed input signals
through the thalamus. There are two func-
tions of sensory cortex; first it manipulates
the sensed input to produce the sensory in-
put that has meaning for control purpose;
and the sensory cortex in real biologi-
cal systems is to appropriately distribute
the incoming sensory input signals to the
amygdala and the orbitofrontal cortex. For
instance, the sensory cortex can be repre-
sented in terms of a computational delay. • Thalamus: Initiates the emotional learning

process upon the sensory inputs. Thalamus
functions as a communicator between the
cortical and the other parts of the loop.
By passing the maximum signal over the
sensory signals through the amygdale, it
shows that the task of the thalamus is to
provide a non-optimal but fast response
from a dynamic system's perspective. The
speed and fault tolerance properties of the
model is improved by this shortcut route
because it bypasses the sensory cortex pro-
cessing and enables the model to generate
a non-optimum action, called satisfactory
decision, even when the sensory cortex
gets damaged.

• Amygdala: The lobe where the stimuli

from the sensory lobes are mapped to emo-
tional responses. The amygdala receives
three kinds of input signals
◦ Lower level information from thala-

mus, e.g., visual information

◦ Middle level information from all

the sensory cortices, e.g., highly ana-
lyzed visual information

◦ Higher level information from differ-

ent parts of the prefrontal cortex. In
fact, these signals are mixed to deliv-
er complete information and context.
For any sensory input signal SI i , the
output signal from the amygdala is