Reading is considered a complex cognitive task which involves visual and linguistic processing which begins with “sensing of the visual stimuli and processing of information through the pathway of the retina, lateral geniculate nuclei and primary visual cortex. At some stage, visual information is probably made available to neuronal systems that apply learned, language-specific rules to convert symbolic images into component representations of language and that perhaps evolved for processing of spoken language” (Vlachos et al.,2007:177).

Ziegler and Goswami define the process of reading as follows: “Reading is about gaining access to meaning from symbols. To access meaning from print, the child must learn the code used by their culture for representing speech by a series of visual symbols. The first steps in becoming literate, therefore require acquisition of the system for mapping distinctive visual symbols onto units of sound (phonology)” (Ziegler & Goswami, 2006: 429).

Carter explains the brain areas used in reading:

  1. “The visual cortex: the text is initially processed in the visual cortex, which sends the information along the “recognition”- processing route towards the language areas of the brain.
  2. The visual word recognition area: this area which evolved to make fine visual distinctions between different objects is “hijacked” by the reader’s brain when it is trained to recognize written text.
  3. The auditory cortex: written words are broken into their phonological elements and “sounded out” so they can be “heard”; the auditory cortex allows the reader to recognize each word by the way it sounds.
  4. Broca’s area: once a word has been recognized, it is also “sounded out” in Broca’s area, linking the written word to the spoken word.
  5. The temporale lobe: this area helps to match the words to their meanings by retrieving memories. Full appreciation of written text – especially fiction- may involve recalling personal memories from the hippocampus” (Carter, 2009:150).

Neuroimaging techniques show that during the higher cognitive function of reading, left-hemisphere cortical areas are activated. However, the act of learning to read may depend on implicit learning processes responsible for acquiring and executing new motor, perceptual and cognitive skills. These processes actually regulate the automation of reading mechanisms (phonological processing, automation of basic articulatory and auditory skills) which may be partially settled by the cerebellum (Vlachos et al.2007).

A good number of neuroscientists conducted research into the impact of reading on cerebral function. One of the first studies was published by Petersen and colleagues, where they used PET to ascertain orthographic results in eight right- handed volunteers. The group was addressed with four different reading tasks: a) real words, b) pseudowords, c) an unpronounceable consonant letter combination and d) false letters. Lateral extrastriate cortex activation was observed during the four tasks. Functional magnetic resonance imaging showed that during the act of reading, a large set or cerebral areas is involved such as the left occipital and temporal cortex, the left frontal operculum, the bilateral –supplementary motor cortex and the cerebellum (Petersen et al.,1998).

The human brain is a structured organ. When processing highly complex tasks as reading a text, it is able to break down the task into easier tasks, assigning them to the appropriate brain areas. Scientists’ knowledge of reading and possible cellular reactions is still limited. However, they do know that during reading, the human brain processes at three main levels:

  • visual features (words-letters);
  • phonological representation of words and letters;
  • meaning of the words and sentences.

 

During the complex act of reading, additional cerebral regions come into play such as the cerebellum that controls automatic eye movements and also parts of the reticular; a network of nerves located in the central area of the brainstem (midbrain, pons, medulla oblongata) that regulates four essential types of function of the body: motor control; sensory control; visceral control; and control of consciousness thus the ability to concentrate on tasks without being distracted (Wren, 2007, Siegel, 1979).

Lina Katsigri PhD
Neurolinguist – Logopedist

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