Teaching shape bias to increase the expressive vocabularies of late talkers

Abstract

Shape bias is a lexical principle that suggests shape is the primary feature by which concrete noun labels apply to other objects. It helps children generalize the labels of newly encountered words to other referents. Shape bias typically develops around two years of age and has been linked with increases in expressive vocabulary. Smith et al. [1], for example, found significant increases in 17-month-olds' noun vocabularies following an intervention that taught shape bias. Methods: The present investigation, a non-randomized pilot study, applied an eight-week shape bias-based intervention to Late Talkers who were between the ages of 23 and 34 months. The eight participants were exposed to novel objects, associated nonsense spoken labels, and objects that did and did not match their shape. Pre-and post-treatment expressive vocabularies were measured using the MacArthur-Bates Communicative Development Inventory [2]. Results: The participants increased their expressive vocabularies by 24 to 119 words, adding more new nouns than other word types. Conclusions: These results, along with lessons learned about implementing the treatment, support larger-scale research on teaching shape bias to positively influence the expressive vocabularies of Late Talkers.

Late Talkers can generalise trained labels by object shape similarities, but not unfamiliar labels

“…In summary, to our knowledge, the present study is one of the first ones to teach the shape bias as an intervention for vocabulary learning in LTs, and one of the first to highlight shape as a way of promoting word learning (see also Niese & Brackenbury, 2020;Singleton & Anderson, 2020). Results confirmed earlier findings (Singleton & Anderson, 2020) that LTs can learn to use shape as the predominant property for extending taught labels (first-order generalisation) when attention is led to shape similarities.…”

“…Research regarding interventions specifically created for LTs is rather limited (e.g. Alt et al, 2014Alt et al, , 2020Girolametto et al, 2013;Hodge & Gaines, 2017;Niese & Brackenbury, 2020). There is generally a focus on teaching specific words or specific communication patterns that LTs do not know, and investigate the effects that this has on children's general vocabulary growth.…”

“…Only limited research has been done regarding developing other general skills that can help develop LT's vocabulary (e.g. Alt et al, 2014Alt et al, , 2020Niese & Brackenbury, 2020). One of these interventions is the VAULT intervention (Alt et al, 2014(Alt et al, , 2020.…”

“…While the shape bias has been identified as one potentially important deficit for LTs' vocabulary development, limited research has been conducted investigating if LTs can acquire a shape bias when being explicitly taught one (e.g. Niese & Brackenbury, 2020). Since the shape bias is related to vocabulary size (Gershkoff-Stowe & Smith, 2004;Perry & Samuelson, 2011), promoting the development of a shape bias may help boost LTs' vocabulary development.…”

“…In other words, an intervention programme targeting a word learning principle that LTs might not have yet acquired is an important step forward in our understanding of the underlying difficulties of LTs' word learning, and it could potentially help LTs develop a useful attentional bias for word learning and generalisation. The results of a pilot study by Niese & Brackenbury (2020) suggest that it might be possible to teach a shape bias to LTs and that it might be beneficial for their vocabulary development. But participants' results varied considerably and since no control group was included in the study, it is unknown whether the shape intervention promoted a vocabulary boost.…”