This post is the first of two that look at a book review written by Karl Friston. Friston is the primary idea man behind embodied cognition (see post Embodied (grounded) Prediction (cognition) so far as I can tell. A book review is a chance to read his ideas in a little less formal and easier to understand environment. He reviews The Age of Insight: the Quest to Understand the Unconscious in Art, Mind, and Brain, from Vienna 1900 to the Present by Eric R. Kandel 2012.
Friston explains that Kandel’s treatment is a book of two parts. The first deals with innovative thinking and insights in science and art in turn of the century Vienna. The second overviews the neurobiology of perception and emotion. The premise that underpins both parts is that the brain is an inference machine, generating hypotheses and fantasies that are tested against sensory data. For Friston, the story starts with Hermann von Helmholtz and the notion of unconscious inference. Kandel places this story in the context of history and art.
In summarizing the context that art provides for understanding functional brain architectures (and vice versa) Kandel concludes:
‘we now know that one of the main reasons expressionist art appeals to us so strongly is that we have evolved a remarkably large, social brain. Moreover, the brain’s mirror neuron systems, theory of mind system and biological modulators of emotions and empathy endow us with a great capacity for understanding other people’s minds and emotions.’
According to Friston and Kandel, there is causal structure in our world that the brain models and embodies in its inferential machinery. Modern versions of Helmholtz’s ideas are now among the most popular explanations for message passing in the brain—generally cast in terms of the Bayesian brain hypothesis or predictive coding. Solid anatomical and physiological evidence points towards predictive coding as the organizing principle for cortical microcircuits and hierarchical brain systems. Friston explains that these top-down predictions are compared with representations at the lower level to form a prediction error (usually associated with the activity of superficial pyramidal cells). This prediction error is then passed back up the hierarchy, to change higher representations (usually associated with the activity of deep pyramidal cells). These changes provide better predictions and thereby reduce prediction error at each and every level of the hierarchy.
‘The insight that the beholder’s perception involves a top-down inference convinced Gombrich that there is no ‘innocent eye’: that is, all visual perception is based on classifying concepts and interpreting visual information. One cannot perceive that which one cannot classify.’
(p. 204). ‘He appreciated the role of cognitive schemata, or internal representations of the visual world in the brain, arguing that every painting owes more to other paintings the viewer has seen than it does to the world actually being portrayed.’ (p. 212)
Kandel further emphasizes the role of history and culture in shaping an otherwise self centered mental world of hypotheses—particularly through the writings of Alios Riegl (1858–1905):
‘In his emphasis on the historical context in which all art emerged and importance of the beholder’s participation for the completion of a painting, Riegl stripped art of its pretension to achieve a universal truth.’ (p. 104).
Riegl was a member of the Venetian School of Art History and figures prominently in Kandel’s treatment of the beholder’s contribution:
‘Just as the artist creates a work of art, so the viewer recreates it by responding to its inherent ambiguity. The extent of the beholder’s contribution depends upon the degree of ambiguity in the work of art.’ (p. 192).
Friston summarizes that:
Ambiguity (or perhaps its resolution) gets to the heart of perceptual inference: there is no point—or pleasure—in making statistical inferences about sure bets. The raison d’eˆ tre for inference is to disambiguate among plausible and competing hypotheses.