Kate Wong Scientific American
The capacity
for abstract thinking does not belong to humans alone, as studies
of other vertebrates, such as primates, pigeons and dolphins,
have shown. Now new research indicates that invertebrates, too,
possess higher cognitive functions. According to a report in the
current issue of the journal Nature, the humble honeybee can form
"sameness" and "difference" concepts—an
ability that may help them in their daily foraging activities.
To probe the
honeybee's mental prowess, Martin Giurfa of the Free University
of Berlin in Germany and his colleagues first trained the insects
to associate certain stimuli with a reward: sugar. For example,
in one experiment bees saw the color blue at the entrance to a
so-called Y-maze. The entrance led to a decision chamber, where
the bees could choose between two paths: one carried a blue target,
the other carried yellow. The bees received a reward only if they
chose blue, the same color as that seen at the entrance.
The team then
tested whether the bees could apply what they had learned to a
new situation. Blue and yellow patches were replaced with black
and white patterns of vertical and horizontal bars. The bees passed
with flying colors, heading straight for the pattern that matched
what they saw at the entrance. Moreover, other experiments revealed
that the insects could even transfer their knowledge across the
senses: bees that learned about sameness through olfactory training
were able to apply that concept to situations involving visual
stimuli.
These results,
the authors conclude, demonstrate that "higher cognitive
functions are not a privilege of the vertebrates." Moreover,
because the honeybee nervous system is relatively simple, they
write, "there is a realistic chance of uncovering the neural
mechanisms that underlie this capacity."
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