Prevention of communicative decline in the cognitively impaired. Intervention on disordered perceptive and productive functions.

Oral communication is the most direct form of communication between people.
Patients with mental retardation have increased risks of communicative failure
and consequent social isolation. In many patients these risks go beyond what
would be expected on the basis of their level of cognitive functioning, but are
caused by impairments in the preception and production of speech. This project
focuses on patients with mental retardation who in addition show hearing
impairment and/or specific impairment of speech production and perception
skills.

Aim of this project is to diagnose hearing impairment, and underlying disorders
in speech perception and production, and to develop and implement adequate
intervention techniques, which are subsequently evaluated. The ultimate goal is
to prevent that in patients with MR hearing impairment and specific
difficulties in listening and speaking communicative skills decline.
The study specifically focuses on input- and output functions. At the
perceptual or input-side: hearing and auditory processing; at the production or
output-side: articulation and speech motor control. The rationale is that in
patients with mental retardation who suffer from specific difficulties in
input- and output- functions, intervention to improve those functions will be
most effective, and will prevent deterioration of communicative and social
functioning.

The first phase of the study comprises screening from the larger group of
patients with mild to moderate mental retardation those patients in whom
communicative and social functioning stays behind their expectancy level. This
will be based on medical records and on inventories of communicative skills and
opportunities.
The second phase entails administration of an extensive battery of cognitive
and speech-language tests, in order to assess the cognitive and speech-language
profile; for a selection of patients also electro-encephalographic (EEG)
recordings will be made.
The third phase is the intervention phase. Patients receive hearing aids
including audiological and logopaedic support, or speech therapy comprising
auditory processing or articulation and speech motor functions. A
baseline-intervention-design will be implemented, in which half the patients
start their intervention 3 months later, after a second assessment.
Phase four comprises evaluation of the intervention: assessments at 3-months
intervals to monitor progress, and a larger evaluation at the end of the
intervention and 9 months later.
Also the communicative abilities will be assessed at the beginning an at the
end of the project.

The function-profile is the starting point for intervention. Patients receive
hearing measures or speech therapy on the basis of their function profile.
Thus, two types of treatment will offered: (1) hearing and speech perception;
(2) articulation and speech motor skills. Treatments are derived from speech
therapeutic intervention strategies for children.
The two types of treatment are the following:
1. Hearing and speech perception: Audiological intervention and specific speech
perception training, in order to improve attention for speech sound, perception
of phonological contrasts, and speech sounds in context.
2. Articulation and speech production: phonological therapy according to
Metaphon; relevant parts of the Dutch Dyspraxia Program (Erlings-van Deurse
e.a., 1993; derived from the Nuffield dyspraxia programme in English).

There are no physical health-risks. Substantial investment of time and exercise
is required from the subjects. However, this could be experienced positively by
the subjects, because of the personal attention during therapy, as well as the
provisioned progress in communicative abilities.