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Executive functions

Executive functions. 37-975-01 Challenges to Language Acquisition: Bilingualism and Language Impairment Dr. Sharon Armon-Lotem Bar Ilan University. Domain General Accounts (Not language specific. Procedural Deficit Hypothesis (PDH) Processing limitations in Executive Functions (EF).

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Executive functions

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  1. Executive functions 37-975-01 Challenges to Language Acquisition: Bilingualism and Language Impairment Dr. Sharon Armon-Lotem Bar Ilan University

  2. Domain General Accounts (Not language specific • Procedural Deficit Hypothesis (PDH) • Processing limitations in Executive Functions (EF)

  3. Procedural Deficit Hypothesis (PDH) Ullman, M.T. & Pierpont, E.I. 2005. Specific Language Impairment is not Specific to Language: The Procedural Deficit Hypothesis. Cortex 41, 399-433. "SLI can be largely explained by the abnormal development of brain structures that constitute the procedural memory system.” • Procedural memory: “mental grammar”, syntax, some morphology • Declarative memory: “mental lexicon”, vocabulary, idioms, irregular past-tense forms

  4. Procedural Memory System: Definition • Brain system involved in “procedural memory” • Learning new and controlling established motor and cognitive skills, habits, and other procedures • E.g. typing, riding a bike, skilled game playing • Aspects of rule-learning • Learning and performing skills involving sequences • Includes system involved in learning, representation, and use of procedural memory

  5. Procedural System: Characteristics • Gradual acquisition of procedures • Learning occurs with practice, over time • Rapid, automatic application • “Implicit Memory System”

  6. Procedural Deficit Hypothesis • Problems with different structures in the PS will result in different types of impairment • Grammatical and lexical retrieval deficits are strongly linked to dysfunctions of the basal ganglia (BG), esp. caudate nucleus, and of the frontal cortex, esp. Broca’s area

  7. PDH: Empirical Evidence • Studies of neural correlates of SLI • Anatomical studies • SLI linked to abnormalities of frontal cortex and basal ganglia • SLI linked to abnormal cerebellar structures • Atypical asymmetry and other abnormalities of declarative system could reflect connectivity or compensation • Event-related potential studies • SLI show atypical ERPs when presented with function words, but not content words • Function words elicit ERPs similar to content words, consistent with declarative system compensation

  8. PDH: Behavioral Evidence • Predictions of PDH • Impairment in rule-governed operations • No impairment in memorized idiosyncratic knowledge (lexicon) • Possible compensation for grammatical/procedural deficit with increased reliance on lexical/declarative memory

  9. Grammatical Profile of SLI • Compensatory shift between PS and DS • People with SLI use declarative memory to memorize complex forms and/or explicit rules • Disproportionate reliance on high-frequency phrases • No difference between regular and irregular past-tense forms • Impairment in production of past-tense forms, but not judgment

  10. Processing limitations in Executive Functions (EF) • Im-Bolter, N., Johnson, J., & Pascual-Leone, J. (2006). Processing limitations in children with specific language impairment: The role of executive function. Child Development, 6, 1822-1841. • Kohnert, K., & Windsor, J. (2004). The search for common ground: Part II. Nonlinguistic performance by linguistically diverse learners. Journal of Speech, Language, and Hearing Research, 47, 891-903.

  11. What are Executive Functions? • Goal-oriented, efficient, and adaptive social behavior. • Capacity to think ahead, suppress impulses,temporarily hold information, and think flexibly. • Needed in carrying out a task that is complicatedor novel, requiring sustained conscious attention (Miller & Cohen, 2001). • Essential in everyday behavior From: Profiles of Executive Function in Developmental and Acquired Disorders: Measurement and Classification, Mariëtte Huizinga, Ph.D., COST Action IS0804

  12. Where does it happen?

  13. Difficulties in executive function • Decision making • Planning • Cognitive flexibility • Inhibition • “Monitoring” of one’s own behavior From: Profiles of Executive Function in Developmental and Acquired Disorders: Measurement and Classification, Mariëtte Huizinga, Ph.D., COST Action IS0804

  14. Executive functions are separable(but not independent) Three ‘core’ executive functions (Miyake et al. 2000): • Updating and monitoring of working memoryrepresentations; • Shifting between tasks or mental sets; • Inhibition of dominant or pre-potent responses. From: Profiles of Executive Function in Developmental and Acquired Disorders: Measurement and Classification, Mariëtte Huizinga, Ph.D., COST Action IS0804

  15. From: Profiles of Executive Function in Developmental and Acquired Disorders: Measurement and Classification, Mariëtte Huizinga, Ph.D., COST Action IS0804

  16. From: Profiles of Executive Function in Developmental and Acquired Disorders: Measurement and Classification, Mariëtte Huizinga, Ph.D., COST Action IS0804

  17. The activatory component or mental attentional capacity (M capacity) is a limited capacity to boost activation of schemes relevant for task performance.Mcapacity is measured in terms of the maximal number of mental schemesFnot directly activated by the here-and-now situationFthat a person can actively hold in mind (i.e., within mental attention) at any one time. Im-Bolter, N., Johnson, J., & Pascual-Leone, J. (2006). Processing limitations in children with specific language impairment: The role of executive function. M capacity - Mental attentional capacity. The maximal number of mental schemes, not directly activated by the here-and-now situation, that a person can actively hold in mind at any one time.

  18. Aim & Hypothesis (p.1826) • “To investigate M capacity and executive function in children with and without SLI to determine whether children with SLI have a general processing deficit or deficits in certain executive processes, and the extent to which these processes are related to language competence”. • “To examine whether potential impairments in general executive processes mediated the relationship between activatory (M) and inhibitory (I) processing resources and language competence”. • “If children with SLI truly have limited processing capacity that is domain general, compared with their chronological age peers, they should perform at a lower stage on all M-measures, regardless of specific domain (i.e., visual vs. verbal).”

  19. Participants

  20. Mental Attentional Capacity (M capacity) - Measures and results A 2 X 3 (M measure) ANOVA with repeated measures on the second factor indicated a main effect for group, F(1, 87)=63.67, p<0.001, and an interaction, F(2, 174)=3.94, p<0.05, but no main effect for M measure, F(2, 174)=0.28, p>0.50. A 2 X 3 (MAM subtest) ANOVA with repeated measures on the second factor results in main effects for group, F(1, 87)=40.82, p<0.0001, and MAM subtest, F(2, 174)=250.97, p<0.0001, but no interaction, F(2, 174)=0.76, p>0.45. Performance for all children decreased as interference increased

  21. The SLI group had lower scores on all three M measures compared with the NL group. • The SLI group performed at a similar level across all three M measures. >> children with SLI have limited processing capacity that is domain general rather than domain specific. • The strength of the group effect was greater for the language/verbal M measures, however, and this suggests that there may be some domain-specific factors (e.g., linguistic executives) that affect verbal processing to a greater degree. • The SLI group performed more poorly than the NL group on tasks of updating and inhibition • The two groups did not differ on tasks of shifting, however.

  22. level of language performance is directly related to the amount of M capacity that one can mobilize; • recentration (updating) but not decentration (shifting) is related to efficient use of processing resources with respect to language • interruption (inhibition) does not have a direct relationship with language competence, but may be related to language performance via its dialectical relationship with M capacity. These results provide evidence for the hypothesis that deficits in updating and inhibition ability affect efficient use of resources for activating relevant information in language tasks.

  23. Kohnert, K., & Windsor, J. (2004). The search for common ground: Part II. Nonlinguistic performance by linguistically diverse learners

  24. Participants

  25. EO=BI EO=BI EO=BI EO=BI *EO<LI *EO<LI EO<LI *EO<LI BI<LI BI<LI BI<LI *BI<LI * p<0.05 Subtle inefficiency in basic non-linguistic processing of children with SLI

  26. Bialystok, E., & Martin, M. (2004). Attention and inhibition in bilingual children: Evidence from the dimensional change card sort task. Developmental Science, 7, 325-339. HEBA 10/1 • Prior, A., & MacWhinney, B. (2010). A bilingual advantage in task-switching. Bilingualism: Language and Cognition, 00(0), 1-10. DANIEL 10/1

  27. Language Proficiency and Executive Control in Bilingual Children with TLD and with SLI Peri Iluz-Cohen Bar Ilan University Ramat-Gan, Israel

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