Archives

  • 2018-07
  • 2018-10
  • 2018-11
  • 2019-04
  • 2019-05
  • 2019-06
  • 2019-07
  • 2019-08
  • 2019-09
  • 2019-10
  • 2019-11
  • 2019-12
  • 2020-01
  • 2020-02
  • 2020-03
  • 2020-04
  • 2020-05
  • 2020-06
  • 2020-07
  • 2020-08
  • 2020-09
  • 2020-10
  • 2020-11
  • 2020-12
  • 2021-01
  • 2021-02
  • 2021-03
  • 2021-04
  • 2021-05
  • 2021-06
  • 2021-07
  • 2021-08
  • 2021-09
  • 2021-10
  • 2021-11
  • 2021-12
  • 2022-01
  • 2022-02
  • 2022-03
  • 2022-04
  • 2022-05
  • 2022-06
  • 2022-07
  • 2022-08
  • 2022-09
  • 2022-10
  • 2022-11
  • 2022-12
  • 2023-01
  • 2023-02
  • 2023-03
  • 2023-04
  • 2023-05
  • 2023-06
  • 2023-07
  • 2023-08
  • 2023-09
  • 2023-10
  • 2023-11
  • 2023-12
  • 2024-01
  • 2024-02
  • 2024-03
  • Unlike adults children s ERPs exhibited an

    2018-10-29

    Unlike adults, children\'s ERPs exhibited an ongoing negativity from 200 to 900msec for agreement errors. During this time fatty acid amide hydrolase the ungrammatical condition was more negative in amplitude than the grammatical condition, similar to a sustained N400 effect; however, after 900msec, the ungrammatical condition begin to demonstrate a more positive amplitude compared to the grammatical condition in children, similar to a delayed P600 effect. Evidence from the time frequency analysis is consistent with our ERP findings such that the predicted beta differences between grammatical and ungrammatical sentences were not present in children. In the earlier time window (500–700msec), children demonstrated a decrease in beta power; however this decrease was not as robust as in adults. In the later time windows (700–900msec and 900–1100msec) children exhibited less of a decrease in beta power than adults for the ungrammatical condition. The ERP and time frequency evidence, taken together, indicate that 10–12 year old children do not engage syntactic unification skills similar to adults. This suggests that while the P600 and beta may be related, future studies are needed to better clarify this connection, or determine beta\'s role in sentence processing. Additionally, we found that children demonstrated a significant N400, but lacked the decrease in theta present in adults for ungrammatical sentences. These findings suggest that children integrate semantic information while making a grammaticality judgment differently than adults. Although children did not demonstrate the expected P600 effect or beta power decrease during processing of the agreement error, very few differences were observed between children and adults in beta or theta for grammatical sentences. Therefore, it appears that developmental differences appear primarily during the error detection process and could be due to the speed and subtlety of the task. Specifically, this task differed from others in that it involved auditory, real-time sentence processing. In visual tasks, semantic and morphosyntactic information is available at the same time, whereas in auditory tasks, semantic and syntactic information can become available at different times, adding to the level of difficulty (Molinaro et al., 2011). Further, the error was an agreement error (i.e. he go, they goes), which is a very subtle error that may not be as obvious as other errors used in past literature, such as word order or gender violations. Although participants were instructed to respond after the completion of the sentence to avoid measuring motor responses during the sentence and ensure phosphorylation attend to the entire sentence, ultimately making reaction time measures unnecessary, past studies have identified differences in how error types are processed using reaction times. A reaction time study revealed that children ages 7–9 years old were better at detecting word-order violations than morphological errors, which the authors contributed to the fact that the English language is a strong word order language with a weak inflectional morphology system (Wulfeck, 1993). Therefore, we speculate that the modality and error type could have influenced children\'s performance and underlying neural processes during this task. Future studies should aim to better identify these influences by measuring reaction times immediately following the error. The lack of a P600 effect between 200 and 900msec was unexpected given that previous research reported a P600-like positivity as early as 3- to 4-years old (Silva-Pereyra et al., 2005a; for review, see Friederici, 2006); however, the finding of a negativity in children\'s ERPs related to a grammatical error is not unique to this study. Hahne et al. (2004) found that, during a grammaticality judgment task, children 7–10 years of age demonstrated a sustained anterior negativity in response to errors, and did not exhibit a P600 effect similar to adults until 13 years of age. The sustained negativity, similar to what we interpret as a prolonged N400 effect in the current study, could be a developmental precursor necessary for future syntactic processing. Behavioral studies have found similar results where function words, or words that are grammatical operators in a language, are not processed quickly and independently from semantic variables until at least 10 years of age. Alternatively, content words, words that bear the semantic bulk of a language, showed adult-like use by 5 years of age (Friederici, 1983). Therefore, words that are semantically robust develop earlier and assist in semantic processing, while words that are the grammatical operators in a language continue to develop, and could contribute to the prolonged development of syntactic processing skills. Cellular research has also found that adults show symmetry in BA 45, engaged in semantic processing, and BA 44, engaged in syntactic processing, while children do not show this symmetry for BA 44 (syntax) until at least eleven years of age, but BA 45 (semantics) develops by age five (Amunts et al., 2003 as cited by Hahne et al., 2004).