FLAT — Blog — UCL Cognition and Grammar Lab

Our paper on familiar collocations in Broca’s aphasia is published!

Bruns, C., Varley, R., Zimmerer, V.C., Carragher, M., Brekelmans, G., & Beeke, S. (2018). “I don’t know”: a usage-based approach to familiar collocations in non-fluent aphasia. Aphasiology. DOI: 10.1080/02687038.2018.1535692

When you talk to someone with Broca’s aphasia, you will find that they predominantly produce single words when trying to get their message across. Despite this non-fluent language output, however, you may also hear short phrases such as “I went to”, “I don’t know” or “it’s alright”. These phrases are a feature of everyone’s language ‘inventory’ – we use them all the time when we converse. It is interesting that individuals with Broca’s aphasia have difficulty to produce grammatical sentences, but that such familiar phrases seem to be preserved. Familiarity of phrases is important to my PhD work, and to this paper.

Zimmerer, V.C., Newman, L., Thomson, R., Coleman, M., & Varley, R.A. (2018). Automated analysis of language production in aphasia and right hemisphere damage: Frequency and collocation strength. Aphasiology, 32(11), 1267-1283. DOI: 10.1080/02687038.2018.1497138

People with aphasia rely on more common words, and more strongly collocated word combinations, in spontaneous language production.

In aphasia, the effects that make a word or sentence easier or harder to process become intensified. Words that take milliseconds longer for a healthy speaker may become out of reach after brain damage. Sentences that are a bit more taxing for grammatical systems may become uninterpretable.

With regards to word processing, theories have long been “usage-based”. How common a word is, when it is typically acquired in development, how abstract its meaning is, all these factors are understood to have an impact on how it is represented in the brain. In a nutshell, common words that were learned early and have concrete meanings (e.g. dog) are easier than rare words that are learned later in life and have abstract meanings (e.g. levity).

However, suggesting that the same factors also play a role at the level of word combinations is still considered crazy in some circles. The field has gotten used to describing grammar using abstract phrase structure rules that have no place for usage patterns. Our paper makes a good argument for rules not being the entire story. We focus on usage frequency as a variable and assume that combinations of words that commonly co-occur are easier to process: I don’t know is easier than I can’t row. Some people with aphasia may find it impossible to produce rarer, or entirely novel, combinations.

(full post on www.vitorzimmerer.net)