Please enable JavaScript.
Coggle requires JavaScript to display documents.
INSIDE THE LETTERBOX: HOW LITERACY TRANSFORMS THE HUMAN BRAIN - Coggle…
INSIDE THE LETTERBOX: HOW LITERACY TRANSFORMS THE HUMAN BRAIN
1)
When we read, we activate the same brain area called
Visual Word Form Area
, also called brain's letterbox
This areas recognize written words, even
unconsciously
and its impariment is associated with pure
alexia
The evolution of this area is explained by the
neural recycling hypothesis
: new cultural objects use pre-existent brain networks recycled
Reading network is constrained by:
Spoken Language areas
Left Superior temporal and inferior frontal regions (left hemisphere)
Lateralized to reduce trasmission time in econding speech sounds
Visual areas
Areas that receive imputs from fovea
To discriminate small shapes
Areas that respond to simple shapes
Macaques have neurons sensitive to letter-like combinations of lines (a sort of primitive alphabet)
Our reading ability is derived from this preexisting neuronal alphabet (
Reading in the Brain
)
The writing systems change, but we use the same set of shapes internalized from the environment
2)
According to the
cortical competition process
, reading process has to shift away the original function
We can study the
architecture of illiterate brain
to demonstrate this (not only educated students such as in the major part of experiments)
We do this comparing illiterates / ex-illiterates / literate adults
The results show an
increased visual word form area
activation correlated with subject's reading score
The results also show
increased primary visual areas
activation (in particular for horizonal checkerboards)
Behaviourally better performance in contour intergation task (more accurate and
efficient
lower-level process
)
Also negative effects in reduced
response to faces
in the left hemisphere
This result is replicated in
children
, initially there is a weaker response to face in the right-hemisphere (then in adults specialization cause the reading incourse)
Studies that compare normal children and
dyslexics
Not negative impact
(at behavioural level the improvement of focusing attention made literate people outperforming in face recognition)
3)
Unlearning Mirror
Invariance indicate our evolutionary ability to generalize between two objects in different directions
Early-reading children and illiterate can consider in the same way the words indipendent of orientations ("b" and "d" are similar)
Visual Word Form Area
seems the area responsible for this adaptation (the same areas presents strongest mirror invariance for pictures)
For this reason, it's not suprising difficulties in recognizing mirror letters before the ages of 9
Determines an increasing in capacity to distinguish them (as mirror-symmetrical pseudo-words)
4)
There are other effects associated with reading
Literacy comes the capacity to recode speech with vision
There is an influence of spelling on speech processing that biases the spoken-language judgments
Determines positive effects such as much larger verbal memory
Literacy enlanches
fast bidirectional connection
between letters and sounds, represented by the links between VWFA and planum temporal
This is studied with the diffusion tensor imaging
Literacy lets language networks to elaborate spoken and written langauge in the same manner
Literacy enlanches the elaboration of
spoken language
(required less activity and mental efforts)
But increasing of
left planum temporale
, responsible for converting letters into sounds
5)
After these discoveries, the next step is to
optimize
the
reading process
(educational practices), for example using the
GraphoGame
to rapid enstablish the relation between brain's visual and phonological circuits