Why the PEC system should only be used for temporary relief

There is no doubt that PEC system is very efficient, allows the child to communicate a need and understand the request of the adult, consequently reduces the frustration of both.

I will try here to present some of the research basis explaining our position for a temporary use only of  any form of  replacement of complex verbal  communication when the child is not deaf.

The incapacity to enunciate has many causes, ranging from an impairment of cranial nerves or vagal system, cortical damage, or damage to the auditory receptors to name only a few. My purpose as expert of development is to find a way to help the child communicate vocally to express needs and emotions by repairing the damaged brain functions.

The PEC system was officially introduced as a tool in speech therapy at the end of 2000. It has great value but can only be considered as a temporary measure because of its inherent risks.

The brain of a child with speech delay is different in morphology, organization and level of activity from the brain of a child with no speech delay. This has been discovered in the first ever study of speech delay using fMRI conducted by Dr Atman(2003) at the Chicago Hospital. He concludes:

Speech-delayed children aged 4 years and older demonstrated a statistically significant increase in right temporal dominance activation, compared with controls (44% vs. 86%). (To be noted here that speech is dominantly processed on the left size of the brain)

Those children also had a statistically significant decrease in total brain activation, compared with controls (46% vs. 82%).

Those children with speech delay will not be able to access naturally and develop their  speech areas, which will lead to a constantly increasing deficit unless the initial damage is mended.

Some technical jargon about where speech is formulated in the brain.

  1. Vocal communication in sentences or group of words is processed, before even enunciation, by seven distributed brain regions’ activity correlated with speech and speech complexity, including five left-sided areas,  one middle frontal gyrus, and two right-sided areas.
  2. Before enunciation, the association of a visual representation to a group of sounds learnt by repetition will involve one central gyrus, one left and right sided posterior brain area, one right sided area.

Experience and repetition will install new connections.

Any protocol used on a long term basis to promote communication out of the pre designed brain areas will draw the new speech brain map and install connections which will be very difficult to modify, simply because it serves a purpose and is easy.

The child’s brain grows according to experience, environmental demands and also to the child’s own genetic makeup. Some of the most crucial developments need to happen in sequence to support the development of other crucial zones, this is what is called in neurophysiology “critical times”

One experience has defined,  in the field of neuroplasticity, what is called “critical times”. This study related to vision but applies to any crucial sensory processing. In this experiment(J Comp Neurol. 1982 ), kittens were set in a device allowing no head movement, and they were placed facing a screen with vertical black and white lines. The exposure lasted only a few days, while the kittens were receiving all other appropriate care. At the end of the experiment, the kittens were let free and it was observed that they had become blind to anything which was not a straight vertical line. This deficit could not be reversed at the time.

A considerable amount of research has been done  evaluating the impact of early experience on the brain shaping and organization.  These 80 years of research confirm that experience will define the brain.

PECS will become the natural communication tool, is this what you really want?

Using a novel communication mode such as pictures is undeniably efficient to help the child learn how to communicate with pictures, which will become his or her “natural” communication system, as the brain  will reorganize to allow this new “nature”.

Speech production is one of the most complex and rapid motor behaviors, and it involves a precise coordination of more than 100 laryngeal, orofacial, and respiratory muscles.  Vocal communication in sentences requires also an involvement of complex facial movements tightly connected to the execution of many important functions such as mastication and swallowing.

To limit verbal communication to the exchange of a visual input on a small size picture, even when accompanied by the enunciation of the label is building a gradual limitation to all those crucial functions of speech.

The brain has one permanent priority which is to preserve energy. If one input can be translated or processed in two different ways, the brain will lean in favour of the less energy-consuming option. Once organized and memorized, the communication with pictures will be the preferred modality for the brain as it requires, as we have seen, much less energy spending.

Deprivation of complex organization at any stages of development will induce physiological and structural changes that will modify the circuitry of all sensory and cognition systems.

A lower demand on the brain, in such delicate and sophisticated areas as those involved in speech lead to a decrease in the number of connections and even a decrease in size of the speech areas.

Some extra reading:

Below is a very small portion of the scientific bibliography supporting this article.

Prog Brain Res. 2006;157:157-72.
Relocation of specific visual functions following damage of mature posterior parietal cortex.
Lomber SG, Yi SK, Woller EM.

Functional anatomy of language and music perception: temporal and structural factors investigated using functional magnetic resonance imaging.
Rogalsky C, Rong F, Saberi K, Hickok G.
J Neurosci. 2011 Mar 9;31(10):3843-52.

Brain. 2009 Jul;132(Pt 7):1918-27. Epub 2009 Jun 4.
Neural processing of spoken words in specific language impairment and dyslexia.
Helenius P, Parviainen T, Paetau R, Salmelin R.

Brain Res Cogn Brain Res. 2004 Sep;21(1):106-13.
Activation in the anterior left auditory cortex associated with phonological analysis of speech input: localization of the phonological mismatch negativity response with MEG.
Kujala A, Alho K, Service E, Ilmoniemi RJ, Connolly JF.

Cereb Cortex. 1996 Sep-Oct;6(5):673-95.
Perceptual and cognitive visual functions of parietal and temporal cortices in the cat.
Lomber SG, Payne BR, Cornwell P, Long KD.

Hum Brain Mapp. 2011 Mar 9. doi: 10.1002/hbm.21181. [Epub ahead of print]
Speech perception in the child brain: Cortical timing and its relevance to literacy acquisition.
Parviainen T, Helenius P, Poskiparta E, Niemi P, Salmelin R.

J Neurosci. 2006 May 31;26(22):6052-61.
Cortical sequence of word perception in beginning readers.
Parviainen T, Helenius P, Poskiparta E, Niemi P, Salmelin R.

Cogn Affect Behav Neurosci. 2007 Mar;7(1):44-52.
Age and culture modulate object processing and object-scene binding in the ventral visual area.

Goh JO, Chee MW, Tan JC, Venkatraman V, Hebrank A, Leshikar ED, Jenkins L, Sutton BP, Gutchess AH, Park DC.

Soc Cogn Affect Neurosci. 2010 Jun;5(2-3):236-41. Epub 2010 Jan 18.
Cultural differences in the lateral occipital complex while viewing incongruent scenes.
Jenkins LJ, Yang YJ, Goh J, Hong YY, Park DC.

J Comp Neurol. 1982 Nov 10;211(4):353-62.
Exposure to lines of only one orientation modifies dendritic morphology of cells in the visual cortex of the cat.
Tieman SB, Hirsch HV.

Cell Mol Neurobiol. 1985 Jun;5(1-2):103-21.
The role of visual experience in the development of cat striate cortex.
Hirsch HV.

J Neurosci. 2011 Mar 9;31(10):3843-52.
Functional anatomy of language and music perception: temporal and structural factors investigated using functional magnetic resonance imaging.
Rogalsky C, Rong F, Saberi K, Hickok G.

Neurologist. 2004 Sep;10(5):235-49.
The motor cortex and facial expression: new insights from neuroscience.
Morecraft RJ, Stilwell-Morecraft KS, Rossing WR.

Neuroscientist. 2011 Feb 28. [Epub ahead of print]
Laryngeal Motor Cortex and Control of Speech in Humans.
Simonyan K, Horwitz B.

Curr Opin Otolaryngol Head Neck Surg. 2004 Jun;12(3):160-5.
Recent advances in laryngeal sensorimotor control for voice, speech and swallowing.
Ludlow CL.

Curr Opin Neurobiol. 2004 Aug;14(4):481-7.
Sparse coding of sensory inputs.
Olshausen BA, Field DJ.

Curr Opin Neurobiol. 2004 Aug;14(4):503-12.
The influence of early experience on the development of sensory systems.
Grubb MS, Thompson ID.

Neuron. 2005 Nov 3;48(3):465-77.
A comparison of experience-dependent plasticity in the visual and somatosensory systems.
Fox K, Wong RO.

Parametrically Dissociating Speech and Nonspeech Perception in the Brain Using fMRI*1
Randall R. Bensonb, a, D. H. Whalenc, Matthew Richardsone, d, Brook Swainsonf, Vincent P. Clarkg, Song Laig and Alvin M. Libermanh, 1

0 replies

Leave a Reply

Want to join the discussion?
Feel free to contribute!

Leave a Reply

Your email address will not be published. Required fields are marked *

HTML tags are not allowed.