Bird Brained

How can we say our brains evolved to read?

When we have only just begun to write;

There must be something built into our sight,

That we recycle when we find the need.

By training sets of pigeons with just feed,

We taught them how to pick words that are right;

How can we say our brains evolved to read?

When we have only just begun to write.

If birds can learn these words we must concede

That reading is not our genetic right,

Nor outcome of the structure of our sight.

For if pigeons pick words without the need,

How can we say our brains evolved to read?

This is a Rondel, written about recent research, which found that pigeons are able to distinguish between four-letter words (e.g. REAL) and nonwords (e.g. REGL) at a level that is comparable to that previously shown by baboons. In the experiments, the pigeons were trained (by rewarding them with food for correct answers) to peck four-letter words when they appeared on a screen, and to peck a designated black, eight-point star when a four-letter nonword appeared. The pigeons that were used in the study were taught new words and nonwords until their ‘vocabularies’ consisted of up to 58 words. The ability to distinguish between these words was significantly higher than that expected by chance.

The fact that writing was invented less than five and a half thousand years ago is a clear sign that human brains have not simply evolved to read (as there has not been enough time for such large-scale evolution to occur). Therefore, one possible suggestion for our ability to read (i.e. the development orthographic processing) is the phenomenon of neuron recycling, in which neural circuits that previously evolved to recognise objects have been repurposed by the brain to recognise words instead. The results of the study with pigeons would suggest that this neuron recycling is not limited to humans and that the visual systems of species which are very different from those of humans (both in terms of genetics and organisation) can also be repurposed to recognise words.

An audio version of the poem can be heard here.