2. Home language environment and brain functions for language Irina Kuzmina, Amanda Hampton Wray, Eric Pakulak, Yoshiko Yamada, & Helen Neville Brain Development Laboratory, University of Oregon Department of Psychology

3. Home language environment & Language Development Home language environment has substantial effects on a child’s language development. Language skills are important for: academic achievement (e.g. reading, and math abilities) Hart & Risley, 1995; Hoff, 2003 Huttenlocher, Vasilyeva, Cymerman, & Levine, 2002, Catts, Adlof, & Weismer, 2006; Pagani, Fitzpatrick, Archambault, & Janosz, 2010

4. Home Language and Vocabulary Development Hart & Risley, 1992; Hart & Risley, 2003 480 utterances per hour 300 utterances per hour 175 utterances per hour Averaged across 2.5 years of observation

5. Goal is to explore the relationship between: parent language input: how much time parents spend reading to and sharing books with their children; language proficiency: a standardized measure of receptive language; neurophysiological measure: event-related brain potentials (ERPs)

6. What are event-related potentials (ERPs)? Continuous brain electrical activity Time-locked to the presentation of stimuli of interest Online, non-invasive index of cognitive processes Temporal resolution of milliseconds

7. Electro-Cap 32-channel; gel for conduction

8. Collecting ERP data Amplifier EEG: Electroencephalogram s2 1 s1 1 s1 2 s1 3... s2 2 ERPs time locked to the onset of critical words

9. Brain Organization for Language Language has different components and ERPs are sensitive to different subcomponents of language: Phonology Syntax Semantics

10. Canonical: She claps her hands happily. Violation: She claps her ball happily. Focus on Semantics Processing Negatively going wave Response to violations of semantic expectations Largest over central and parietal electrode sites N400

11. ERPs and language processing “Mature” N400 (adults): shorter duration, focal distribution N400 (young children): prolonged latency, more spread

12. Current Project Brain organization and processing for language are related to experience and language proficiency. Research question: How does parent and child joint reading relate to neural processing for semantics? Hypothesis: Children with higher reading input will display more mature N400. Pakulak & Neville, 2010; Yamada, Harris, Pakulak, Schachter, Neville, 2002, Hampton Wray & Weber-Fox, under revision

13. Method ERPs were recorded for 3-5 year-old children (N = 35) Questionnaires completed by parents: self-report of parent reading and sharing books with their children Median split: high and low reading input groups Groups were matched on receptive language proficiency.

14. Paradigm for assessing brain functions for language using ERPs child-friendly ecologically valid highly engaging

15. Results Paradigm validity: Children (3-5 year old) Adults Replicated previous results Significant N400 in time windows 350-950 ms and 950-1600 ms N400

16. Group Differences High Reading InputLow Reading Input No differences in mean amplitudes in time windows 350-950 ms or 950-1600 ms Late time window (1600-2300 ms): distribution difference

17. Results: distribution difference Low reading group shows a negativity that is more broadly distributed in the late time window High reading group: negativity only over right hemisphere (condition by hemisphere interaction, p =,03) Low reading group: negativity over both hemispheres (no condition by hemisphere interaction, p =.43)

18. Discussion We may not see differences in the earlier time windows because groups were matched for language proficiency. Right-lateralized pattern, observed in the high reading input group in the late time window resembles the N400 distribution typically found in adults. The bilateral distribution observed in the low reading input group may suggest recruitment of additional systems for language processing, that usually are not related to semantic processing.

19. Acknowledgments Brain Development Laboratory UO Summer Program for Undergraduate Research (SPUR) NIH/NIDCD R01 DC00481-21