Using Early Words to Communicate Intentions- a Comparison of Toddlers with Autistic Spectrum Disorder and Toddlers with Typical Development

Background:

About 70% of toddlers with Autism Spectrum Disorder (ASD) present delayed emergence of speech, a difficulty attributed to several factors, among them their core deficit in communication. Restrictions in the use of early words for various communicative intentions is among the earliest manifestations of ASD. The majority of toddlers with ASD eventually develop functional speech, hence, a close analysis of the function of early words and how they are used in context is highly desirable.

Objectives:

1. To study how toddlers with ASD use their early words to convey various communicative intentions
2. To compare the contexts in which Typically Developing (TD) toddlers and toddlers with ASD at similar lexical levels produce words.

Methods:

24 mother-toddler dyads participated in the study: In nine dyads, the toddlers had been diagnosed with ASD prior to the study; in fifteen dyads, the toddlers were typically developing. Toddlers in the two groups were matched by lexical levels at study entry. Each mother–toddler dyad was video-recorded three times, during naturalistic interaction. The first recording took place when toddlers reached a productive lexicon of 40-70 different words. Two additional recordings took place in intervals of two months. All verbal productions were classified into four main communicative intentions (Declarative, Requesting, Protesting and Non- Communicative speech). The frequency of each communicative intention was calculated in order to characterize within-group developmental changes (i.e., the developmental rate of each participant), as well as differences between the two groups.

Results:

1. Toddlers with ASD were delayed in the emergence of first words, compared to the TD toddlers (31.5 months and 17 months, respectively). In addition, a greater within-group variability was found in the ASD group.

2. In contrast to our assumption, in both groups, the most common communicative intention was Declarative: throughout the three visits, words were used to describe or comment, rather than to request items or activities. However, a statistically higher percentage of declaratives was found among toddlers with TD (F(2,21)=7.41, p<0.01). Both groups rarely used their words to protest or to object.

3. In both groups, the majority of productions was directed towards the communicative partner. However, toddlers with ASD used words for non-communicative purposes more often than TD toddlers (F (2,21)=14.81,p<0.01).

4. A statistically-significant higher frequency of approach- withdrawal, crying and self- stimulation was noted in the ASD group (i.e. for withdrawal: F (1,22)=1.14, p<0.01). In the TD group, a statistically significant higher frequency of showing and pointing was recorded (F (1,22)=4.65, p<0.05; F (1,22)=8.39, p<0.01, respectively).

Conclusions:

While TD toddlers begin to talk with an already-established knowledge of the main communicative functions of words, toddlers with ASD seem to have only partial understanding, and they improve as they expand their productive lexicon. The relative paucity of verbal requests and protests in both groups might be attributed to the unstructured setting. In the ASD group, non- verbal behaviours may have served as an alternative to requests or protests. These findings bear both theoretical importance and practical implications for early intervention for toddlers with ASD.