Picture recognition in animals and humans

D. Bo6et, J. Vauclair/Beha6ioural Brain Research 109 (2000) 143-165

Table 4

Experiments showing difficulties recognizing pictures in animals

A study by Watanabe [105] is particularly interesting
in the discussion of picture recognition because it sug-
gests that object-picture equivalence can be performed
relatively easily when there is some functional basis.
Twenty-four pigeons were divided into four experimen-
tal groups: two object-to-picture groups and two pic-
ture-to-object groups; one of the object-to-picture
groups and one of the picture-to-object groups were
trained on a natural concept (food objects were S + for
half, and non-food objects were S - , and it was the
opposite for the remaining half) while the other two
groups were trained on a pseudoconcept (an arbitrary
grouping of edible and nonedible objects as positive and
negative stimuli). When tested with the natural concept,
the subjects showed a good transfer of discrimination in
both object-to-picture and picture-to-object conditions,
but no transfer was observed with the pseudoconcept.
Such a result indicates that picture recognition can
depend on the consistency of the task.

5.2.2. Reactions to motion picture

Attempts to train domestic hens to transfer from real
stimuli to video images generally produced negative
results, although, depending on experimental condi-
tions, the birds could use some features of the patterns
(e.g. the colour) in their discrimination [73]. It was
concluded from this study that complex video images,
such as those required to recognise social stimuli, are
not equivalent to the real stimuli. In addition, some
pigeons did not transfer a learned discrimination from
live conspecifics to their photographs and had great
difficulties in discriminating between slides of individu-
als (although they easily discriminated live conspecifics).

The results of the studies reported in this section are
somewhat contradictory to the findings summarised in
Sections 3 and 4. In effect, they demonstrate that picture
recognition in animals is not obvious and is dependent
on experimental factors. In several experiments, mon-
keys and birds (such as pigeons and chicken) failed to
display an interest in photographs of conspecifics.
Moreover, different tasks involving picture recognition
have reported a failure to demonstrate such an ability;
thus chimpanzees failed to realise a cross modal match-
ing and only one monkey (out of four), which was

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