Albert Gjedde

Brains on books

Albert Gjedde
04/12 2019
12:15-13:15, D-IAS Conference Room, SDU, Odense

Brains on Books

By Albert Gjedde, Professor of Translational Neurobiology, Department of Nuclear Medicine (OUH), University of Southern Denmark


Here, I claim that reading is a form of prediction. Great debates have emerged of the biological origin of brain functions. A current consensus claims that brains capable of predictive coding evolved in animals particularly to allow movements of the animals and their body parts under circumstances of comparative safety. As movements by definition begin now and move into a more or less distant future, comparative safety of motion is assured by sufficient accuracy of prediction of future challenges that in turn rests on memories. The memories are used as projections “back to the future”, formed in the prefrontal cortex center of consciousness. As language originally required motion of fingers, hands, lips, tongue, and throat, and still requires motion in the process of formulation of a text in any medium, it is not surprising that interpretation of texts in the shape of books or other forms of display also depend on processes that originally emerged as signals in the form of movement (Zatorre et al. 1992, Vafaee et al. 2004, Mangen et al. 2019).

Recent scientific evidence confirms that the reading of books, rather than being a more or less passive reaction to a textual stimulus, in reality is an action, a series of projections of material from memory in the form of predictions. The projections lead to a certain clash with reality that has consequences that allow the mind of the reader (“consciousness”) to adopt the projection with the most salient interpretation and minimal consequences. The choice of the most successful projection is the key to the conscious assimilation of a text. The activations of the brain structures during reading reflect the joint work of neuronal pathways activated by stimuli that connect the visual cortex and sites of memory storage (“dendritic spines”) to the prefrontal cortex by two routes, the dorsal route or “high road”, and the ventral route or “low road”, both transmitting projections that arise from consciousness (Smallwood et al. 2013).

Much of the knowledge of neuronal functions comes from the consideration of malfunctions. Dyslexia is a malfunction of reading that has raised the interest of researchers in the mechanisms of the human brain that are engaged in reading, in attempts to answer the question of why some people cannot read properly. A more general question of course is why some people can’t do everything the sum of all other people can do? The distribution of brain functionality among the members of humanity suggest that the ability to read is not a fixed feature of the brain but a spectrum of learned competences that defy attempts to fix precisely the threshold of transition from reading to dyslexia (Bailey et al. 2018).

Smallwood J, Gorgolewski KJ, Golchert J, Ruby FJ, Engen H, Baird B, Vinski MT, Schooler JW, Margulies DS. The default modes of reading: modulation of posterior cingulate and medial prefrontal cortex connectivity associated with comprehension and task focus while reading. Front Hum Neurosci. 2013 Nov 12;7:734. doi: 10.3389/fnhum.2013.00734.

Bailey SK, Aboud KS, Nguyen TQ, Cutting LE. Applying a network framework to the neurobiology of reading and dyslexia. J Neurodev Disord. 2018 Dec 13;10(1):37. doi: 10.1186/s11689-018-9251-z.

Mangen A, Olivier G, Velay JL. Comparing Comprehension of a Long Text Read in Print Book and on Kindle: Where in the Text and When in the Story? Front Psychol. 2019 Feb 15;10:38. doi: 10.3389/fpsyg.2019.00038.

Vafaee MS, Gjedde A. Spatially dissociated flow-metabolism coupling in brain activation. Neuroimage. 2004 Feb;21(2):507-15.

Zatorre RJ, Evans AC, Meyer E, Gjedde A. Lateralization of phonetic and pitch discrimination in speech processing. Science. 1992 May 8;256(5058):846-9.