Vocabulary Intervention for Late Talkers

Most studies regarding word learning have focused on understanding when and how infants learn words. At 24 months, typically developing infants know between 200 and 300 words and add new words to their vocabularies at a rapid rate. It is also during the first years of life that some principles that promote vocabulary learning are developed. The shape bias, which is a tendency to infer that objects that share the same shape will also share the same name, is the one that has been studied the most. At 24 months, typically developing infants use this principle as a strategy to learn novel words. In contrast, Late Talkers (children with a language delay in the absence of a physiological, cognitive or genetic disorder that may account for this delay) do not exhibit this preference. It has been found that teaching typically developing infants a shape bias prior to the end of the second year of life can boosts their word learning. Despite this, the possibility of teaching Late Talkers this principle and its effect on their vocabulary and language development has not been explored.

Over a series of 9 weekly sessions, Late Talkers (diagnosed by Language Therapists from the Birmingham Community Healthcare National Health Services Foundation Trust, United Kingdom) will be introduced to one of two possible interventions: a shape bias intervention and a more conventional intervention called "specific word intervention". Both interventions will be compared after 9 weeks. One year later, a follow up study will be conducted to assess the long-term effects each intervention has in word learning. Participants will be referred by a Speech and Language Therapists from the Birmingham Community Healthcare National Health Services Foundation Trust, United Kingdom, and all assessments and interventions will take place at the Infant and Child Lab at the University of Birmingham, United Kingdom.

The objectives of the present study are:

A. To investigate whether it is possible to teach Late Talkers to attend to objects' shapes as a useful property for learning and generalizing novel object labels.

B. To assess the benefits that this intervention programme has on Late Talkers' short-term vocabulary development compared to an intervention where infants will be taught specific words ('specific word' intervention).

C. Assess whether the success of teaching Late Talkers a shape bias for noun extension is related to their sensitivity to object shape similarities.

D. Assess whether the success of teaching Late Talkers a shape bias for noun extension is related to their ability of sustain their attention to novel objects that are presented to them.

E. To assess the benefits of the intervention programme on language and cognitive development one year after the intervention compared to the 'specific word' intervention

Eligibility Criteria:
Inclusion Criteria:

* Children (boys and girls) between 24 and 48 months.
* Children from Birmingham (United Kingdom) and its surrounding areas.
* Monolingual English native speakers
* Children with a moderate or severe language delay, as diagnosed by a Speech and Language Therapist of the Birmingham Community Healthcare National Health Service Foundation Trust, United Kingdom.

Exclusion Criteria:

* Children with a developmental, physiological, neurological or cognitive disorder that could explain their language delay.
* Children with a mild language delay, as diagnosed by a Speech and Language Therapist of the Birmingham Community Healthcare National Health Service Foundation Trust, United Kingdom.
* Children that speak or know another language different than English, either as first or additional language.