Who Needs Emotions? The Brain Meets the Robot

eware the passionate robot 353
3. A “simple” imitation system: we hypothesize that brain mechanisms
supporting a simple imitation system—imitation of novel
object-directed actions through repeated exposure—for grasping
developed in the 15 million-year evolution from the common
ancestor of monkeys and apes to the common ancestor of
apes and humans.
4. A “complex” imitation system: we hypothesize that brain
mechanisms supporting a complex imitation system—acquiring
(longer) novel sequences of more abstract actions in a single
trial—developed in the 5 million-year evolution from the common
ancestor of apes and humans along the hominid line that
led, in particular, to Homo sapiens.
5. Protosign, a manual-based communication system, resulting from
the freeing of action from praxis to be used in pantomime and
then in manual communication more generally.
6. Protospeech, a vocal-based communication system exploiting the
brain mechanisms that evolved to support protosign.
7. Language. Arbib (2002) argues that stages 6 and 7 are separate,
characterizing protospeech as being the open-ended production
and perception of sequences of vocal gestures, without implying
that these sequences have the syntax and semantics adequate
to constitute a language. But the stages may be interleaved.
Nonhuman primates have a call system and orofacial gestures expressive
of a limited range of emotional and related social indicators. However,
we do not regard primate calls as the direct precursor of speech. Combinatorial
properties for the openness of communication are virtually absent in
basic primate calls, even though individual calls may be graded. Moreover,
the neural substrate for primate calls is in a region of the cingulate cortex
distinct from F5. The mirror-system hypothesis offers detailed reasons why
Broca’s area—as the homologue of F5—rather than the area already involved
in vocalization, provided the evolutionary substrate for language.
Consciousness, Briefly
We have now established that vision is no single faculty but embraces a wide
variety of capabilities, some mediated by subcortical systems, others involving
cooperation between these and other, more highly evolved systems in
the cerebral cortex. The evolution of manual dexterity went hand in hand
[!] with the evolution of a dorsal cortical pathway dedicated to extracting
the visual affordances appropriate to that dexterity and a ventral cortical