sentence processing

CUNY 2017

Here are my abstract and poster for CUNY 2017.

Our experiment was a first attempt to test a direct, causal relation between prediction and learning. We find that prediction itself doesn’t explain how children learn novel words, but 3-year-olds and 4-year-olds who predict and redirect attention toward the novel referent were more successful in learning. That being said, learning 12 novel words in just a few minutes was clearly difficult for children, as indicated by their low accuracy at test. In sum, further experiments are needed to evaluate the role of prediction in learning, and to clarify what other factors (e.g., cognitive control) are involved during learning.

It was a great time, as always, despite the snow!

Looking forward to CUNY 2018!

rochester NIRS workshop

It’s been a long time since my last post (tisk tisk!) so here I am, catching up.

Last week one of my advisors, Lauren Emberson, hosted a NIRS workshop at the University of Rochester. NIRS (near-infrared spectroscopy) is a non-invasive imaging technique used to measure the metabolic activity in the cortex. (For a great review, see Aslin, 2012.) Basically, when areas of the cortex are more active, this requires additional metabolic support, so more oxygenated hemoglobin is transferred to the location of activation. Light is absorbed differentially for oxygenated hemoglobin and deoxygenated hemoglobin, so our measure is essentially how much light the cortex in an approximate area is absorbing during x measurement time. (Note: I say “approximate” because one of the downsides of current NIRS systems is low spatial resolution, as compared to fMRI, so we can’t make super exact claims about cortical areas.) NIRS is an excellent method to use with infants, because the imaging doesn’t require rigid head stabilization. Infants wear a cap (similar to EEG) and can sit on their parent’s lap while watching+/listening to audio+/visual stimuli.

This was a great opportunity – both to learn more about the NIRS methodology and recent literature, but also to bond with my future labmates. Here are a few pictures from the trip:

IMG_6900  IMG_6935

BUCLD 2014

This year, I gave a talk on children’s comprehension of truth-functional negation at BUCLD.

The main point of my talk is that pragmatic support is important for processing the negative form, but other factors (e.g., processing demands) play a role as well. We found that 3-year-olds interpret negation incrementally with supportive discourse context. However, we found that 2-year-olds had difficulty switching flexibly between affirmative and negative statements (Study 2) and only successfully comprehended both forms in a blocked design with affirmative trials first (Study 3).

Here are slides for reference and here is the complete abstract. I’m currently working on writing this work up for publication with Roman Feiman and Jesse Snedeker, so stay tuned for the manuscript!

CUNY 2014

Here’s my poster from CUNY 2014 (Columbus, OH): CUNY 2014 Processing Negation

And the submitted abstract:

Young children’s comprehension of negation

Tracy Brookhyser, Roman Feiman, & Jesse Snedeker (Harvard University)

Negation is a crucial test case for understanding incremental semantic interpretation, because its compositional representation is inconsistent with expectations generated by lexical items (see e.g. Panizza, 2012). Early processing studies found negative sentences were initially interpreted like their affirmative counterparts, raising the possibility that early predictive processing is associative (Kaup, Lüdtke & Zwaan, 2006; Fischler, et al., 1983). However, subsequent studies with richer discourse context found adults can rapidly integrate negation into their sentence interpretation (Nieuwland & Kuperberg, 2008; Tian, Breheny & Ferguson, 2010). No such result exists with children, and recent evidence suggests children 3 and younger do not process negation incrementally (Nordmeyer & Frank, 2013). We used the visual world paradigm to examine online sentence comprehension. Children heard a story, with corresponding pictures, which established a discourse context for both the negative and affirmative sentences (e.g. DW plans to color two stars but is interrupted), then heard the critical sentence and response prompt (e.g. “DW didn’t color/colored one of the stars. Which one was it?”). We previously found adults show incremental interpretation of negation in these contexts. Adapting this method to children, we found older children (n = 16, M = 42 mos) and younger children (n = 28, M = 31 mos) performed differently (Fig 1). In our online measures, we analyzed the proportion of fixations to the affirmative target (e.g. the colored star) for the time between VP offset and NP onset. In older children, a mixed effects model found solely an effect of polarity (p = .01). In younger children, there was an interaction between vocabulary, measured by MCDI, and polarity (p = 0.01). There was a marginal effect of polarity among younger children with higher MCDI scores (p = .07). In offline measures, older children’s picture selection was above chance in affirmative (77%) and negative (86%) trials, but younger children performed at chance in affirmative (60%) and negative (52%) trials, despite good performance in unambiguous practice trials (81%). Overall, results suggest 2-year-olds have difficulty resolving competition from two similar referents, regardless of polarity, though those with higher vocabularies may do somewhat better. 3-year-olds do not appear to have particular difficulty interpreting negation. Critically, we find no evidence that initial interpretation is associative (e.g. early affirmative fixations in both conditions). In this context, negative utterances are interpreted as quickly and accurately as affirmatives, suggesting incremental compositional processes in both cases.