There is a rich literature in cognitive psychology that highlights the importance of
opportunities to recall and produce newly taught information when learning. The use of
retrieval practice during a learning phase improves long-term retention between 50% and
150% relative to conditions without retrieval prompts. Recent work documents the power of
retrieval practice in word learning studies with preschoolers with developmental language
disorders. Though retrieval practice is not new, its application to child learning is in
its infancy. Given the striking learning effects that have been documented in adults and
emerging findings in children [with language impairment, retrieval practice has great
potential to enhance learning in autistic children, a population with significant
vocabulary deficits that often persist into adulthood.
Though autistic children have initial strengths in learning word form information
(phonological), these word form advantages do not persist over time. Autistic children
also demonstrate weaknesses in developing robust semantic representations, which have
been noted by recalling fewer semantic features of newly taught words. Also, autistic
children have difficulties in generalizing newly taught knowledge, which can hinder
flexible vocabulary use. It has been suggested that autistic children may need more
input, time, or practice than typically developing children to develop strong lexical
representations.
In addition to deficits in breadth and depth of word knowledge, many autistic children
demonstrate an atypical receptive-expressive vocabulary profile, with a reduced receptive
advantage. Despite traditional therapy approaches recommending that receptive skills be
targeted before expressive skills in autistic children, research indicates that it may be
more effective to target expressive skills (i.e., word production) prior to targeting
receptive skills. One recent study demonstrated that autistic children are more
successful when learning words if they are prompted to name newly taught items rather
than to identify (point to) a picture of these items. Targeting word expression led to
more successful cross-modal generalization, with success extending to word comprehension
(i.e., expressive-to-receptive generalization). This new finding holds promise for
clinical practice; however, it has not been connected to a strong mechanistic
explanation, which is necessary to strengthen the support for this practice.
Retrieval-practice theory can provide the key mechanistic explanation that is required.
It has been proposed that effortful retrieval (now referred to as repeated spaced
retrieval; RSR for clarity) enhances encoding because the retrieval of new information,
or the attempt to do so, prompts individuals to identify features of the word or concept
that are necessary to reconstruct the material, which leads to the development of an
enriched and potentially elaborated memory trace to support future retrievals. RSR holds
promise for autistic children because it may strengthen item-specific learning of
phonological and semantic information (word form and meaning) that persists beyond
immediate tests of learning. Furthermore, RSR may enable generalization (e.g., applying
noun labels to new referents and adjectives to different objects). Thus, our specific
aims are:
Aim 1: To determine whether repeated spaced retrieval (RSR) of labels (nouns) results in
more robust learning of word form and meaning relative to a learning schedule that does
not prompt retrieval.
In Study 1, 4- to 8-year-old autistic children will learn [novel nouns] in an RSR
condition and a Repeated Study only (RS) condition. The investigators hypothesize that
the children will recall more labels (word form) and semantic information (meaning) for
RSR words and that their learning gains will persist at the 1-week test.
Aim 2: To determine whether repeated spaced retrieval (RSR) of adjectives results in more
robust learning relative to a learning schedule that does not prompt retrieval. Study 2
will examine novel adjective learning, which has not been examined in autistic children.
Autistic children will learn novel adjectives for unusual attributes displayed on
familiar objects (e.g., "The cow is zogy."). It is predicted that the children will
benefit from the RSR schedule when learning adjectives at immediate and 1-week tests.
Aim 3: To determine whether RSR enhances learning to the extent that children are able to
generalize newly learned words to new images/referents. To demonstrate durable learning,
the investigators will test beyond the explicitly taught stimuli. Study 1 will examine
whether children will extend the labels (nouns) to referents that differ slightly in
positioning and color. Study 2 will test for generalization of the newly taught
adjectives when applied to objects from different categories (e.g., a zogy cow [taught]
and zogy table [generalization]). It is predicted that generalization will be higher for
words taught in the RSR condition than the RS condition.
Aim 4: To explore the moderating effect of autism severity on response to RSR. The
investigators will examine whether autism symptom severity moderates word learning
overall and if it predicts whether children benefit from RSR relative to RS learning
schedules in Studies 1 and 2. The investigators will also explore associations between
word learning and cognitive, vocabulary, and grammatical skills, and when warranted,
statistically control for these variables.