Minds and Computers : An Introduction to the Philosophy of Artificial Intelligence

temporal lobe
olfactory bulbs
optic chiasm
medulla
cerebellum
frontal lobe
pons
frontal lobe
temporal lobe
cerebellum
Figure 4.2
Intact brain – base view.

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modality which is not routed through the thalamus. Interestingly, it is
also the only sensory modality which is not cross-lateralised in the
hemispheres, which means that – unlike the other senses – inform-
ation from the left nostril goes to the left olfactory bulb and infor-
mation from the right nostril goes to the right olfactory bulb.
The basal ganglia are known to also be implicated in motor pro-
cessing. They are closely linked with the cerebellum and the midbrain.
Su
fferers of degenerative conditions associated with the basal
ganglia, such as Huntington’s chorea, experience uncontrollable
bodily movements, typically more pronounced than the tremors
experienced by su
fferers of Parkinson’s disease.
The limbic system, sometimes referred to as the limbic lobe, is
nestled around the top of the brain stem. It contains, among other
structures, the hippocampus which is known to be implicated in
memory processing and the amygdala which is known to play a role
with respect to emotion. The limbic system is sometimes described as
being part of the cerebral hemispheres.
The cerebral hemispheres constituting the cerebrum are what most
people imagine when they think of the brain. It is worth mentioning
that all the neural structures of the brain, not just the cerebral hemi-
spheres, are mirrored along a line drawn longitudinally through
the centre of the spinal cord. The cerebral hemispheres are joined
to each other by a thick bundle of neural fibres called the corpus
callosum.
The two cerebral hemispheres are each involved with the process-
ing of one half of the body’s sensory and motor functions and these
functions are, with the exception of olfaction, cross-lateralised in the
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