Clinical Trial Details
— Status: Completed
Administrative data
| NCT number |
NCT06001866 |
| Other study ID # |
1603017480B |
| Secondary ID |
R01DC014708 |
| Status |
Completed |
| Phase |
N/A
|
| First received |
|
| Last updated |
|
| Start date |
March 1, 2023 |
| Est. completion date |
January 25, 2024 |
Study information
| Verified date |
April 2024 |
| Source |
Purdue University |
| Contact |
n/a |
| Is FDA regulated |
No |
| Health authority |
|
| Study type |
Interventional
|
Clinical Trial Summary
Children with developmental language disorder (DLD; also referred to as specific language
impairment) experience a significant deficit in language ability that is longstanding and
harmful to the children's academic, social, and eventual economic wellbeing. Word learning is
one of the principal weaknesses in these children. This project focuses on the word learning
abilities of four- and five-year-old children with DLD. The goal of the project is to build
on the investigators' previous work to determine whether, as has been found thus far, special
benefits accrue when these children must frequently recall newly introduced words during the
course of learning. The focus of the current study is verb-learning. The goal of the study is
to increase children's absolute levels of learning while maintaining the advantage that
repeated retrieval holds over comparison methods of learning.
Description:
Developmental Language Disorder (DLD) affects language learning in an estimated 7% of
children. Although much of the research literature has emphasized difficulties learning
grammar, children with DLD also have major deficits in vocabulary. In recent work, the
investigators have been examining the benefit of retrieval practice to enhance word learning
and retention in preschoolers with DLD. The rationale behind this work is grounded in the
growing literature in the field of cognitive psychology which shows that repeated practice in
retrieving information results in greater long-term retention than continuous study of that
information without opportunities for retrieval. In addition, retrieval practice that occurs
after a delay-or "spacing" between study of a word and subsequent recall attempts-can lead to
stronger effects.
The investigators have explored the benefits of retrieval practice for preschoolers with DLD
and with typical language development (TD), showing that recall and retention for novel words
(nouns, adjectives, verbs) were greater when learned using repeated spaced retrieval (RSR)
than when learned using repeated study only. Despite benefitting from RSR, children with DLD
still showed lower levels of recall than children with TD, in particular in novel verb
learning.
In the current study, the investigators seek to improve the absolute levels of word form
recall for verbs by modifying the method used previously. Sixteen children with DLD will be
recruited for this study along with 16 children with TD matched on chronological age. Using a
within-subjects design, children will learn eight novel verbs, four at a time. Each set of
four will be learned over two consecutive days, with two words in the RSR condition and two
words in a repeated study condition. The referents for these novel words will be
video-recorded transitive actions performed by actors on objects and presented on a laptop
screen.
In the RSR condition, children will initially hear the word paired with a video of a novel
action, immediately be asked to recall the word, and then see/hear it again. After three
other words are presented, they will be asked to recall the original word again; this "3"
spaced retrieval schedule will continue for the rest of the learning session. In the
comparison condition, children will simply hear the words paired with a video of the novel
action. In this study, during retrieval practice, children will be prompted to respond with a
full sentence containing the verb.
Recall of the verbs will be tested after the learning session on the second day and one week
later. At one week, children will also complete a syntactic generalization test in which they
are prompted to use the novel verb in a type of sentence that is different from the one used
during learning. Finally, children will complete a two-alternative recognition test.
The investigators hypothesize that novel verbs that undergo RSR during the learning period
will be learned and recalled better than comparable novel verbs that are assigned to the
repeated study condition. This RSR advantage will continue to be observed when the children
must use the novel verbs with new actors and objects and will be seen as well in the
syntactic generalization test when the children must use the novel verbs in a new sentence
frame. Introducing novel verbs representing actions that can be performed on varying objects
is expected to improve overall learning. In addition, by having the child produce the verbs
in the context of a full sentence, the newly learned verbs should become more integrated with
other sentence elements (subjects and direct objects), resulting in a richer representation
in memory and consequently, greater recall, recognition, and syntactic flexibility than was
observed in the previous novel verb study.
