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Anderson JAE, Yurtsever A, Fisher-Skau O, Cherep LA, MacPhee I, Luk G, Grundy JG. Examining the consistency in bilingualism and white matter research: A meta-analysis. Neuropsychologia 2024; 195:108801. [PMID: 38244768 DOI: 10.1016/j.neuropsychologia.2024.108801] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2023] [Revised: 11/28/2023] [Accepted: 01/15/2024] [Indexed: 01/22/2024]
Abstract
This study aimed to systematically investigate the relationship between bilingualism, age, L2 onset age of acquisition (AoA), and white matter integrity (operationalized as fractional anisotropy, FA), addressing inconsistencies in the literature. We conducted a meta-analysis of 23 studies and used meta-regression models to assess the influence of age and L2AoA on effect sizes in studies comparing monolinguals and bilinguals. Even though the overall between-group effect size across the whole brain was unreliable, bilingualism was associated with increased white matter integrity in specific tracts and in groups with a limited range of age and L2AoA. Age had a small, negative effect on white matter integrity, with differences between monolinguals and bilinguals more pronounced in younger adults, consistent with a view of an initial increase in white matter integrity, followed by remodeling for efficiency over time. In contrast, later L2AoA was associated with greater white matter integrity in bilinguals than monolinguals, again consistent with the remodeling for efficiency model. Our findings highlight the importance of considering age and L2AoA when examining the neural basis of bilingualism on white matter in the brain and how bilingualism contributes to structural changes that stave off cognitive decline in older age.
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Affiliation(s)
- John A E Anderson
- Department of Cognitive Science, Carleton University, Department of Psychology, Canada.
| | | | - Odin Fisher-Skau
- Department of Cognitive Science, Carleton University, Department of Psychology, Canada
| | | | - Imola MacPhee
- Department of Cognitive Science, Carleton University, Department of Psychology, Canada
| | - Gigi Luk
- Department of Educational & Counselling Psychology, McGill University, Canada
| | - John G Grundy
- Iowa State University, Department of Psychology, USA
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Larsen BA, Klinedinst BS, Wolf T, McLimans KE, Wang Q, Pollpeter A, Li T, Mohammadiarvejeh P, Fili M, Grundy JG, Willette AA. Adiposity and insulin resistance moderate the links between neuroelectrophysiology and working and episodic memory functions in young adult males but not females. Physiol Behav 2023; 271:114321. [PMID: 37567373 PMCID: PMC10592072 DOI: 10.1016/j.physbeh.2023.114321] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2023] [Revised: 07/26/2023] [Accepted: 08/08/2023] [Indexed: 08/13/2023]
Abstract
INTRODUCTION Obesity and insulin resistance negatively influence neural activity and cognitive function, but electrophysiological mechanisms underlying these interrelationships remain unclear. This study investigated whether adiposity and insulin resistance moderated neural activity and underlying cognitive functions in young adults. METHODS Real-time electroencephalography (EEG) was recorded in 38 lean (n = 12) and obese (n = 26) young adults with (n = 15) and without (n = 23) insulin resistance (18-38 years, 55.3% female) as participants completed three neurocognitive tasks in working memory (Operation Span), inhibitory control (Stroop), and episodic memory (Visual Association Test). Body fat percentage was quantified by a dual-energy X-ray absorptiometry scan (DEXA/DXA). Fasting serum insulin and glucose were quantified to calculate Homeostatic Model Assessment for Insulin Resistance (HOMA-IR) values, for which a higher value indicates more insulin resistance. Hierarchical moderated regression analysis tested these interrelationships. RESULTS In males, greater frontal negative slow wave (fNSW) and positive slow wave (PSW) amplitudes were linked to higher working memory accuracy in participants with low, but not high, body fat percentage and HOMA-IR levels. In contrast, body fat percentage and HOMA-IR did not moderate these associations in females. Furthermore, body fat percentage and HOMA-IR values moderated the relationship between greater fNSW amplitudes and better episodic memory accuracy in males, but not females. Finally, body fat percentage and insulin resistance did not moderate the link between neural activity and inhibitory control for either sex. CONCLUSION Young adult males, but not females, with higher body adiposity and insulin resistance showed reduced neural activity and worse underlying working and episodic memory functions.
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Affiliation(s)
- Brittany A Larsen
- Department of Behavioral Science, MD Anderson Cancer Center, 1515 Holcombe Blvd., Houston, TX 77030, United States of America
| | - Brandon S Klinedinst
- Department of Medicine, University of Washington, RR-512, Health Sciences Building, Box 356420, 1959 NE Pacific St., Seattle, Washington, 98195, United States of America
| | - Tovah Wolf
- Lifecare Alliance, 1699 W Mound St., Columbus, Ohio, 43223, United States of America
| | - Kelsey E McLimans
- Nutrition and Dietetics Department, Viterbo University, 900 Viterbo Dr., La Crosse, Wisconsin, 54601, United States of America
| | - Qian Wang
- Department of Food Science and Human Nutrition, College of Human Sciences, Iowa State University, 2312 Food Sciences Building, 536 Farm House Ln., Ames, Iowa, 50011, United States of America
| | - Amy Pollpeter
- Bioinformatics and Computational Biology Graduate Program, Department of Biomedical Sciences, College of Veterinary Medicine, Iowa State University, 1800 Christensen Dr., Ames, Iowa, 50011, United States of America
| | - Tianqi Li
- Genetics and Genomics Graduate Program, Department of Food Science and Human Nutrition, College of Human Sciences, Iowa State University, 2312 Food Sciences Building, 536 Farm House Ln., Ames, Iowa, 50011, United States of America
| | - Parvin Mohammadiarvejeh
- Department of Industrial and Manufacturing Systems Engineering, College of Engineering, Iowa State University, 3004 Black Engineering, 2529 Union Dr., Ames, Iowa, 50011, United States of America
| | - Mohammad Fili
- Department of Industrial and Manufacturing Systems Engineering, College of Engineering, Iowa State University, 3004 Black Engineering, 2529 Union Dr., Ames, Iowa, 50011, United States of America
| | - John G Grundy
- Department of Psychology, College of Liberal Arts and Sciences, Iowa State University, 901 Stange Rd., Ames, Iowa, 50011, United States of America
| | - Auriel A Willette
- Department of Food Science and Human Nutrition, College of Human Sciences, Iowa State University, 2312 Food Sciences Building, 536 Farm House Ln., Ames, Iowa, 50011, United States of America; Department of Psychology, College of Liberal Arts and Sciences, Iowa State University, 901 Stange Rd., Ames, Iowa, 50011, United States of America; Department of Neurology, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, 200 Hawkins Dr., 2007 Roy Carver Pavilion, Iowa City, Iowa, 52242, United States of America.
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Calvo N, Grundy JG, Bialystok E. Bilingualism modulates neural efficiency at rest through alpha reactivity. Neuropsychologia 2023; 180:108486. [PMID: 36657519 DOI: 10.1016/j.neuropsychologia.2023.108486] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2022] [Revised: 12/20/2022] [Accepted: 01/15/2023] [Indexed: 01/18/2023]
Abstract
The aim of the present study was to investigate how resting state EEG rhythms reflect attentional processes and bilingual experience. We compared alpha and beta rhythms for monolingual and bilingual young adults in eyes open and eyes closed conditions using EEG measures of frequency power, reactivity, and coherence. Power shows the amount of brain activity at a given frequency band; reactivity indexes the desynchronization of neuronal activity when individuals open their eyes at rest; and coherence indicates the brain regions that have correlated activity. The results showed that bilinguals had similar alpha power as monolinguals in both resting conditions but less alpha reactivity across the whole scalp. There was also more focused activation for bilinguals expressed as more coherence in posterior electrodes, particularly when eyes were opened to direct attention. For beta, there were no group differences in power or reactivity, but there was higher coherence for monolinguals than bilinguals, a pattern consistent with previous literature showing that beta frequency was related to language learning and native language proficiency. These results are in line with a neural efficiency theory and suggest that bilinguals have a more efficient brain for attentional mechanisms than monolinguals at rest.
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Affiliation(s)
- Noelia Calvo
- Department of Psychology, York University, Toronto, ON, Canada
| | - John G Grundy
- Department of Psychology, Iowa State University, Ames, IA, USA
| | - Ellen Bialystok
- Department of Psychology, York University, Toronto, ON, Canada.
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Abstract
Early research that relied on standardized assessments of intelligence reported negative effects of bilingualism for children, but a study by Peal and Lambert (1962) reported better performance by bilingual than monolingual children on verbal and nonverbal intelligence tests. This outcome led to the view that bilingualism was a positive experience. However, subsequent research abandoned intelligence tests as the assessment tool and evaluated performance on cognitive tasks, making the research after Peal and Lambert qualitatively different from that before their landmark study, creating a disconnect between the new and earlier research. These newer cognitive studies showed both positive effects of bilingualism and no differences between language groups. But why were Peal and Lambert's results so different from previous studies that were also based on intelligence tests? The present study analyzed data from verbal and nonverbal intelligence tests that were collected from 6,077 participants across 79 studies in which intelligence tests were administered as background measures to various cognitive tasks. By including adults, the study extends the results across the life span. On standardized verbal tests, monolinguals outperformed bilinguals, but on nonverbal measures of intelligence, there were no differences between language groups. These results, which are different from those reported by Peal and Lambert, are used to reinterpret their findings in terms of the sociolinguistic, political, and cultural context in which the Peal and Lambert study was conducted and the relevance of those factors for all developmental research. (PsycInfo Database Record (c) 2022 APA, all rights reserved).
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Chung-Fat-Yim A, Calvo N, Grundy JG. The Multifaceted Nature of Bilingualism and Attention. Front Psychol 2022; 13:910382. [PMID: 35719564 PMCID: PMC9205563 DOI: 10.3389/fpsyg.2022.910382] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2022] [Accepted: 05/12/2022] [Indexed: 11/13/2022] Open
Abstract
Attention has recently been proposed as the mechanism underlying the cognitive effects associated with bilingualism. However, similar to bilingualism, the term attention is complex, dynamic, and can vary from one activity to another. Throughout our daily lives, we use different types of attention that differ in complexity: sustained attention, selective attention, alternating attention, divided attention, and disengagement of attention. The present paper is a focused review summarizing the results from studies that explore the link between bilingualism and attention. For each level of attention, a brief overview of relevant theoretical models will be discussed along with a spotlight on paradigms and tasks used to measure these forms of attention. The findings illustrate that different types and levels of attention are modified by the variety of bilingual experiences. Future studies wishing to examine the effects of bilingualism on attention are encouraged to embrace the complexity and diversity of both constructs rather than making global claims about bilingualism and attention.
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Affiliation(s)
- Ashley Chung-Fat-Yim
- Department of Communication Sciences and Disorders, Northwestern University, Evanston, IL, United States
| | - Noelia Calvo
- Department of Psychology, York University, Toronto, ON, Canada
| | - John G Grundy
- Department of Psychology, Iowa State University, Ames, IA, United States
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Wagner D, Bialystok E, Grundy JG. What Is a Language? Who Is Bilingual? Perceptions Underlying Self-Assessment in Studies of Bilingualism. Front Psychol 2022; 13:863991. [PMID: 35645938 PMCID: PMC9134110 DOI: 10.3389/fpsyg.2022.863991] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2022] [Accepted: 04/08/2022] [Indexed: 11/13/2022] Open
Abstract
Research on the cognitive consequences of bilingualism typically proceeds by labeling participants as "monolingual" or "bilingual" and comparing performance on some measures across these groups. It is well-known that this approach has led to inconsistent results. However, the approach assumes that there are clear criteria to designate individuals as monolingual or bilingual, and more fundamentally, to determine whether a communication system counts as a unique language. Both of these assumptions may not be correct. The problem is particularly acute when participants are asked to classify themselves or simply report how many languages they speak. Participants' responses to these questions are shaped by their personal perceptions of the criteria for making these judgments. This study investigated the perceptions underlying judgments of bilingualism by asking 528 participants to judge the extent to which a description of a fictional linguistic system constitutes a unique language and the extent to which a description of a fictional individual's linguistic competence qualifies that person as bilingual. The results show a range of responses for both concepts, indicating substantial ambiguity for these terms. Moreover, participants were asked to self-classify as monolingual or bilingual, and these decisions were not related to more objective information regarding the degree of bilingual experience obtained from a detailed questionnaire. These results are consistent with the notion that bilingualism is not categorical and that specific language experiences are important in determining the criteria for being bilingual. The results impact interpretations of research investigating group differences on the cognitive effects of bilingualism.
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Affiliation(s)
- Danika Wagner
- Department of Psychology, York University, Toronto, ON, Canada
| | - Ellen Bialystok
- Department of Psychology, York University, Toronto, ON, Canada
| | - John G. Grundy
- Department of Psychology, Iowa State University, Ames, IA, United States
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Grundy JG. The Specificity and Reliability of Conflict Adaptation: A Mouse-Tracking Study. Front Psychol 2022; 12:770509. [PMID: 35087450 PMCID: PMC8786903 DOI: 10.3389/fpsyg.2021.770509] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2021] [Accepted: 12/17/2021] [Indexed: 11/13/2022] Open
Abstract
Researchers have recently begun to question the specificity and reliability of conflict adaptation effects, also known as sequential congruency effects (SCEs), a highly cited effect in cognitive psychology. Some have even used the lack of reliability across tasks (e.g., Flanker, and Stroop) to argue against models of cognitive control that have dominated the field for decades. The present study tested the possibility that domain-general processes across tasks might appear on more sensitive mouse-tracking metrics rather than overall reaction times. The relationship between SCE effects on the Stroop and Flanker tasks were examined for the first time using a mouse-tracking paradigm. Three main findings emerged: (1) Robust SCEs were observed for both the Stroop and Flanker tasks at the group level, (2) Within-task split-half reliabilities for the SCE across dependent variables were weak at best and non-existent in many cases, and (3) SCEs for the Flanker and Stroop tasks did not correlate with each other for overall reaction times, but did show significant correlations between tasks on more dynamic measures that captured processes before response execution. These findings contribute to the literature by highlighting how mouse-tracking may be a fruitful avenue by which future studies can examine the specificity and reliability of conflict adaptation and tease apart different theoretical models producing the effects.
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Affiliation(s)
- John G Grundy
- Department of Psychology, Iowa State University, Ames, IA, United States
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Anderson JAE, Grundy JG, Grady CL, Craik FIM, Bialystok E. Bilingualism contributes to reserve and working memory efficiency: Evidence from structural and functional neuroimaging. Neuropsychologia 2021; 163:108071. [PMID: 34715120 DOI: 10.1016/j.neuropsychologia.2021.108071] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2021] [Revised: 09/14/2021] [Accepted: 10/22/2021] [Indexed: 01/26/2023]
Abstract
This study compared brain and behavioral outcomes for monolingual and bilingual older adults who reported no cognitive or memory problems on three types of memory that typically decline in older age, namely, working memory (measured by n-back), item, and associative recognition. The results showed that bilinguals were faster on the two-back working memory task than monolinguals but used a set of frontostriatal regions less than monolinguals. There was no group difference on an item/associative recognition task. In brain structure, gray matter volume and white matter integrity (fractional anisotropy) were generally lower in bilinguals than in monolinguals, but bilinguals had better white matter integrity than monolinguals in the bilateral superior corona radiata and better gray matter density in the left inferior temporal gyrus. These regions may help preserve bilinguals' executive functions despite generally more significant atrophy throughout the brain than monolinguals in that these structures contribute to efficient communication between executive frontal regions and subcortical motor regions, and perceptual pathways. Reliable negative correlations between brain structure and age were only observed in bilinguals, and to the extent that bilinguals (but not monolinguals) had better brain structure, their performance was enhanced. Collectively, the findings provide evidence for reserve in bilingual older adults.
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Affiliation(s)
- John A E Anderson
- Carleton University, Departments of Cognitive Science and Psychology, Canada.
| | - John G Grundy
- Iowa State University, Department of Psychology, United States
| | - Cheryl L Grady
- Rotman Research Institute at Baycrest Hospital, Canada; University of Toronto, Department of Psychiatry, Canada; University of Toronto, Department of Psychology, Canada
| | - Fergus I M Craik
- Rotman Research Institute at Baycrest Hospital, Canada; University of Toronto, Department of Psychology, Canada
| | - Ellen Bialystok
- Rotman Research Institute at Baycrest Hospital, Canada; York University, Department of Psychology, Canada
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Grundy JG, Pavlenko E, Bialystok E. Bilingualism modifies disengagement of attention networks across the scalp: A multivariate ERP investigation of the IOR paradigm. J Neurolinguistics 2020; 56:100933. [PMID: 36061571 PMCID: PMC9439621 DOI: 10.1016/j.jneuroling.2020.100933] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
A recent approach to explaining the domain-general cognitive outcomes of bilingualism is to consider the role of disengagement of attention, rather than the engagement of focused attention or inhibition as typical in most accounts. The present study pursues this approach by examining the neurophysiological changes associated with disengagement of attention in young adults performing an inhibition of return (IOR) paradigm while EEG was recorded. Participants were drawn from a diverse community and varied widely in their bilingual experience. There were three main findings. First, dividing the sample into dichotomous groups based on language proficiency did not lead to reliable group differences on the task. Second, using instead continuous measures of bilingualism across the sample indicated that greater bilingual experience and proficiency were associated with the magnitude of the IOR effect, with more bilingual individuals showing larger and earlier IOR effects. Finally, a network of processes that are temporally and spatially distinct were found to work together to produce facilitation, disengagement of attention, and inhibition of return. These findings contribute to debates regarding the electrophysiological correlates of the IOR effect and provide additional evidence for how bilingualism affects domain-general cognition.
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Affiliation(s)
| | - Elena Pavlenko
- Charité – Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health
- QUEST – Center for Transforming Biomedical Research, Berlin Institute of Health (BIH), 10178 Berlin, Germany
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Grundy JG, Bialystok E. When a "Replication" Is Not a Replication. Commentary: Sequential Congruency Effects in Monolingual and Bilingual Adults. Front Psychol 2019; 10:797. [PMID: 31031674 PMCID: PMC6474323 DOI: 10.3389/fpsyg.2019.00797] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2019] [Accepted: 03/25/2019] [Indexed: 11/13/2022] Open
Affiliation(s)
- John G Grundy
- Department of Psychology, Iowa State University, Ames, IA, United States
| | - Ellen Bialystok
- Department of Psychology, York University, Toronto, ON, Canada
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Grundy JG, Bialystok E. Monolinguals and bilinguals disengage attention differently following conflict and errors: Evidence from ERPs. Brain Cogn 2018; 128:28-36. [PMID: 30447505 DOI: 10.1016/j.bandc.2018.11.006] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2018] [Revised: 08/06/2018] [Accepted: 11/08/2018] [Indexed: 11/19/2022]
Abstract
Monolingual and bilingual young adults performed a task-switching experiment while EEG was recorded to investigate how bilingualism affects cognitive control following conflict. Participants were given pure blocks composed of three intermixed tasks, each consisting of univalent trials in which they responded to one feature of the stimulus - color, shape, or size. In the crucial conflict block, an irrelevant feature was added to one of the tasks, creating bivalent trials that included conflict. Behaviorally, all participants slowed responses to univalent trials that followed conflict, reflecting the post-conflict slowing effect. Electrophysiologically, monolinguals displayed longer-lasting post-conflict ERP effects and showed larger ERN amplitudes following responses than bilinguals, amplitudes that were associated with adjustments in response times. The interpretation is that bilinguals disengage attention following conflict from misleading stimuli or error responses more rapidly than do monolinguals.
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Affiliation(s)
- John G Grundy
- Department of Psychology, Iowa State University, Iowa, USA.
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Till C, Green R, Grundy JG, Hornung R, Neufeld R, Martinez-Mier EA, Ayotte P, Muckle G, Lanphear B. Community Water Fluoridation and Urinary Fluoride Concentrations in a National Sample of Pregnant Women in Canada. Environ Health Perspect 2018; 126:107001. [PMID: 30392399 PMCID: PMC6371693 DOI: 10.1289/ehp3546] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
BACKGROUND Fluoride exposures have not been established for pregnant women who live in regions with and without community water fluoridation. OBJECTIVE Our aim was to measure urinary fluoride levels during pregnancy. We also assessed the contribution of drinking-water and tea consumption habits to maternal urinary fluoride (MUF) concentrations and evaluated the impact of various dilution correction standards, including adjustment for urinary creatinine and specific gravity (SG). METHODS We measured MUF concentrations in spot samples collected in each trimester of pregnancy from 1,566 pregnant women in the Maternal-Infant Research on Environmental Chemicals cohort. We calculated intraclass correlation coefficients (ICCs) to assess variability in MUF concentrations across pregnancy. We used regression analyses to estimate associations between MUF levels, tea consumption, and water fluoride concentrations as measured by water treatment plants. RESULTS Creatinine-adjusted MUF values ([Formula: see text]; milligrams per liter) were almost two times higher for pregnant women living in fluoridated regions ([Formula: see text]) compared with nonfluoridated regions ([Formula: see text]; [Formula: see text]). MUF values tended to increase over the course of pregnancy using both unadjusted values and adjusted values. Reproducibility of the unadjusted and adjusted MUF values was modest ([Formula: see text]). The municipal water fluoride level was positively associated with creatinine-adjusted MUF ([Formula: see text], 95% CI: 0.46, 0.57), accounting for 24% of the variance after controlling for covariates. Higher MUF concentrations correlated with numbers of cups of black ([Formula: see text] but not green tea ([Formula: see text]). Urinary creatinine and SG correction methods were highly correlated ([Formula: see text]) and were interchangeable in models examining predictors of MUF. CONCLUSION Community water fluoridation is a major source of fluoride exposure for pregnant women living in Canada. Urinary dilution correction with creatinine and SG were shown to be interchangeable for our sample of pregnant women. https://doi.org/10.1289/EHP3546.
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Affiliation(s)
- Christine Till
- Faculty of Health, York University, Toronto, Ontario, Canada
| | - Rivka Green
- Faculty of Health, York University, Toronto, Ontario, Canada
| | - John G Grundy
- Faculty of Health, York University, Toronto, Ontario, Canada
| | - Richard Hornung
- Pediatrics and Environmental Health, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, USA
| | - Raichel Neufeld
- Faculty of Health, York University, Toronto, Ontario, Canada
| | | | - Pierre Ayotte
- Department of Social and Preventive Medicine, Laval University, Quebec, Quebec, Canada
- Centre de Recherche du CHU de Québec, Université Laval, Quebec, Quebec, Canada
| | - Gina Muckle
- Centre de Recherche du CHU de Québec, Université Laval, Quebec, Quebec, Canada
- School of Psychology, Laval University, Quebec, Quebec, Canada
| | - Bruce Lanphear
- Faculty of Health Sciences, Simon Fraser University, Vancouver, British Columbia, Canada
- Child & Family Research Institute, BC Children's Hospital, University of British Columbia, Vancouver, British Columbia, Canada
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Anderson JAE, Grundy JG, De Frutos J, Barker RM, Grady C, Bialystok E. Effects of bilingualism on white matter integrity in older adults. Neuroimage 2018; 167:143-150. [PMID: 29175203 PMCID: PMC5845836 DOI: 10.1016/j.neuroimage.2017.11.038] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2017] [Revised: 10/19/2017] [Accepted: 11/18/2017] [Indexed: 02/03/2023] Open
Abstract
Bilingualism can delay the onset of dementia symptoms and has thus been characterized as a mechanism for cognitive or brain reserve, although the origin of this reserve is unknown. Studies with young adults generally show that bilingualism is associated with a strengthening of white matter, but there is conflicting evidence for how bilingualism affects white matter in older age. Given that bilingualism has been shown to help stave off the symptoms of dementia by up to four years, it is crucial that we clarify the mechanism underlying this reserve. The current study uses diffusion tensor imaging (DTI) to compare monolinguals and bilinguals while carefully controlling for potential confounds (e.g., I.Q., MMSE, and demographic variables). We show that group differences in Fractional Anisotropy (FA) and Radial Diffusivity (RD) arise from multivariable interactions not adequately controlled for by sequential bivariate testing. After matching and statistically controlling for confounds, bilinguals still had greater axial diffusivity (AD) in the left superior longitudinal fasciculus than monolingual peers, supporting a neural reserve account for healthy older bilinguals.
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Affiliation(s)
| | - John G Grundy
- Department of Psychology, York University, Toronto, Ontario, Canada
| | - Jaisalmer De Frutos
- Laboratory of Cognitive and Computational Neuroscience, Center for Biomedical Technology, Pozuelo de Alarcón, Spain; Biological and Health Psychology Department, Universidad Autónoma de Madrid, Madrid, Spain
| | - Ryan M Barker
- Department of Psychology, York University, Toronto, Ontario, Canada
| | - Cheryl Grady
- Baycrest Rotman Research Institute, Toronto, ON, Canada; University of Toronto, Departments of Psychology and Psychiatry, Canada
| | - Ellen Bialystok
- Department of Psychology, York University, Toronto, Ontario, Canada; Baycrest Rotman Research Institute, Toronto, ON, Canada.
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Timmer K, Grundy JG, Bialystok E. The influence of contextual cues on representations in the mental lexicon for bilinguals. Bilingualism 2017. [DOI: 10.1075/bpa.6.06tim] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Affiliation(s)
- Kalinka Timmer
- Department of Psychology, York University /Departament de Tecnologies de la Informació i les Comunicacions, Universitat Pompeu Fabra
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Timmer K, Grundy JG, Bialystok E. Earlier and more distributed neural networks for bilinguals than monolinguals during switching. Neuropsychologia 2017; 106:245-260. [DOI: 10.1016/j.neuropsychologia.2017.09.017] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2017] [Revised: 07/18/2017] [Accepted: 09/18/2017] [Indexed: 11/28/2022]
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Abstract
In a recent commentary, Goldsmith and Morton (in press) argue that the results of a study demonstrating smaller sequential congruency effects (SCEs) for bilinguals than for monolinguals (Grundy, Chung-Fat-Yim, Friesen, Mak, & Bialystok, 2017) is incorrect in its interpretation of SCEs. Moreover, their overall framework is that there is no evidence for any cognitive differences between monolingual and bilingual young adults. Here, we provide evidence in support of our original interpretation and challenge their basis for arguing that there are no language group differences on these cognitive measures.
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Grundy JG, Anderson JAE. Commentary: The Relationship of Bilingualism Compared to Monolingualism to the Risk of Cognitive Decline or Dementia: A Systematic Review and Meta-Analysis. Front Aging Neurosci 2017; 9:344. [PMID: 29118711 PMCID: PMC5660966 DOI: 10.3389/fnagi.2017.00344] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2017] [Accepted: 10/13/2017] [Indexed: 11/24/2022] Open
Affiliation(s)
- John G Grundy
- Department of Psychology, York University, Toronto, ON, Canada
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Grundy JG, Anderson JAE, Bialystok E. Bilinguals have more complex EEG brain signals in occipital regions than monolinguals. Neuroimage 2017; 159:280-288. [PMID: 28782680 PMCID: PMC5671360 DOI: 10.1016/j.neuroimage.2017.07.063] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2017] [Revised: 07/13/2017] [Accepted: 07/30/2017] [Indexed: 11/24/2022] Open
Abstract
Brain signal complexity increases with development and is associated with better cognitive outcomes in older age. Research has also shown that bilinguals are able to stave off cognitive decline for longer periods of time than monolinguals, but no studies to date have examined whether bilinguals have more complex brain signals than monolinguals. Here we explored the hypothesis that bilingualism leads to greater brain signal complexity by examining multiscale entropy (MSE) in monolingual and bilingual young adults while EEG was recorded during a task-switching paradigm. Results revealed that bilinguals had greater brain signal complexity than monolinguals in occipital regions. Furthermore, bilinguals performed better with increasing occipital brain signal complexity, whereas monolinguals relied on coupling with frontal regions to demonstrate gains in performance. These findings are discussed in terms of how a lifetime of experience with a second language leads to more automatic and efficient processing of stimuli and how these adaptations could contribute to the prevention of cognitive decline in older age.
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Grundy JG, Chung-Fat-Yim A, Friesen DC, Mak L, Bialystok E. Sequential congruency effects reveal differences in disengagement of attention for monolingual and bilingual young adults. Cognition 2017; 163:42-55. [PMID: 28273520 PMCID: PMC5398762 DOI: 10.1016/j.cognition.2017.02.010] [Citation(s) in RCA: 55] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2016] [Revised: 02/12/2017] [Accepted: 02/25/2017] [Indexed: 11/17/2022]
Abstract
Three studies examined the hypothesis that bilinguals can more rapidly disengage attention from irrelevant information than monolinguals by investigating the impact of previous trial congruency on performance in a simple flanker task. In Study 1, monolingual and bilingual young adults completed two versions of a flanker task. There were no differences between language groups on mean reaction time using standard analyses for congruent or incongruent trials or the size of the flanker effect. Sequential congruency effects (SCEs) however, which account for previous trial congruency, were smaller for bilinguals than for monolinguals. This finding was strongest at the shortest response-to-stimulus interval (RSI). Study 2 replicated this effect using a slightly different flanker task and a shorter RSI than study 1. Study 3 showed that at long RSIs, where behavioral SCE differences between groups disappear because of sufficient time to recover from the previous trial, event-related potentials demonstrated a continued influence of previous trial congruency for monolinguals but not bilinguals at both the N2 and the P3, replicating the reaction time effects in Studies 1 and 2. Together, these studies demonstrate that bilinguals experience less influence from previous trial congruency and have greater ability to disengage attention from the previous trial in order to focus attention on the current trial than is found for monolinguals.
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Grundy JG, Anderson JAE, Bialystok E. Neural correlates of cognitive processing in monolinguals and bilinguals. Ann N Y Acad Sci 2017; 1396:183-201. [PMID: 28415142 DOI: 10.1111/nyas.13333] [Citation(s) in RCA: 101] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2016] [Revised: 02/13/2017] [Accepted: 02/16/2017] [Indexed: 01/05/2023]
Abstract
Here, we review the neural correlates of cognitive control associated with bilingualism. We demonstrate that lifelong practice managing two languages orchestrates global changes to both the structure and function of the brain. Compared with monolinguals, bilinguals generally show greater gray matter volume, especially in perceptual/motor regions, greater white matter integrity, and greater functional connectivity between gray matter regions. These changes complement electroencephalography findings showing that bilinguals devote neural resources earlier than monolinguals. Parallel functional findings emerge from the functional magnetic resonance imaging literature: bilinguals show reduced frontal activity, suggesting that they do not need to rely on top-down mechanisms to the same extent as monolinguals. This shift for bilinguals to rely more on subcortical/posterior regions, which we term the bilingual anterior-to-posterior and subcortical shift (BAPSS), fits with results from cognitive aging studies and helps to explain why bilinguals experience cognitive decline at later stages of development than monolinguals.
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Affiliation(s)
- John G Grundy
- Department of Psychology, York University, Toronto, Ontario, Canada
| | | | - Ellen Bialystok
- Department of Psychology, York University, Toronto, Ontario, Canada
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Abstract
Previous research has shown that bilingual children outperform their monolingual peers on a wide variety of tasks measuring executive functions (EF). However, recent failures to replicate this finding have cast doubt on the idea that the bilingual experience leads to domain-general cognitive benefits. The present study explored the role of disengagement of attention as an explanation for why some studies fail to produce this result. Eighty children (40 monolingual, 40 bilingual) who were 7 years old performed a task-switching experiment. In the pure blocks, three simple non-conflict tasks were performed in which children responded by pressing one of two response keys. In the conflict block, occasional bivalent stimuli appeared and created conflict because the irrelevant dimension was mapped to the incorrect response key. The results showed that these bivalent stimuli affected subsequent performance in the conflict block. For monolinguals, the effect of conflict was found for up to 12 trials after the appearance of the bivalent stimulus, but for bilinguals the effect disappeared after only two trials. The results are interpreted as evidence for faster disengagement of attention by bilingual children. Most studies examining EF in monolingual and bilingual children do not examine trial-by-trial adjustments following conflict, but these are essential considerations because relevant processing differences are masked when analyses are applied to data averaged across entire blocks.
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Affiliation(s)
- John G Grundy
- Department of Psychology, York University, Toronto, Canada
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Grundy JG, Nazar S, O'Malley S, Mohrenshildt MV, Shedden JM. The Effectiveness of Simulator Motion in the Transfer of Performance on a Tracking Task Is Influenced by Vision and Motion Disturbance Cues. Hum Factors 2016; 58:546-559. [PMID: 27068771 DOI: 10.1177/0018720816639776] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/06/2015] [Accepted: 02/20/2016] [Indexed: 06/05/2023]
Abstract
OBJECTIVE To examine the importance of platform motion to the transfer of performance in motion simulators. BACKGROUND The importance of platform motion in simulators for pilot training is strongly debated. We hypothesized that the type of motion (e.g., disturbance) contributes significantly to performance differences. METHODS Participants used a joystick to perform a target tracking task in a pod on top of a MOOG Stewart motion platform. Five conditions compared training without motion, with correlated motion, with disturbance motion, with disturbance motion isolated to the visual display, and with both correlated and disturbance motion. The test condition involved the full motion model with both correlated and disturbance motion. We analyzed speed and accuracy across training and test as well as strategic differences in joystick control. RESULTS Training with disturbance cues produced critical behavioral differences compared to training without disturbance; motion itself was less important. CONCLUSION Incorporation of disturbance cues is a potentially important source of variance between studies that do or do not show a benefit of motion platforms in the transfer of performance in simulators. APPLICATION Potential applications of this research include the assessment of the importance of motion platforms in flight simulators, with a focus on the efficacy of incorporating disturbance cues during training.
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Hannah SD, Shedden JM, Brooks LR, Grundy JG. Event-related potentials reveal the relations between feature representations at different levels of abstraction. Q J Exp Psychol (Hove) 2015; 69:2166-88. [PMID: 26513169 DOI: 10.1080/17470218.2015.1106565] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
In this paper, we use behavioural methods and event-related potentials (ERPs) to explore the relations between informational and instantiated features, as well as the relation between feature abstraction and rule type. Participants are trained to categorize two species of fictitious animals and then identify perceptually novel exemplars. Critically, two groups are given a perfectly predictive counting rule that, according to Hannah and Brooks (2009. Featuring familiarity: How a familiar feature instantiation influences categorization. Canadian Journal of Experimental Psychology/Revue Canadienne de Psychologie Expérimentale, 63, 263-275. Retrieved from http://doi.org/10.1037/a0017919), should orient them to using abstract informational features when categorizing the novel transfer items. A third group is taught a feature list rule, which should orient them to using detailed instantiated features. One counting-rule group were taught their rule before any exposure to the actual stimuli, and the other immediately after training, having learned the instantiations first. The feature-list group were also taught their rule after training. The ERP results suggest that at test, the two counting-rule groups processed items differently, despite their identical rule. This not only supports the distinction that informational and instantiated features are qualitatively different feature representations, but also implies that rules can readily operate over concrete inputs, in contradiction to traditional approaches that assume that rules necessarily act on abstract inputs.
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Affiliation(s)
- Samuel D Hannah
- a Department of Brain, Behaviour & Neuroscience , McMaster University , Hamilton , ON , Canada.,b Department of Psychology , University of Saskatchewan , Saskatoon , SK , Canada
| | - Judith M Shedden
- a Department of Brain, Behaviour & Neuroscience , McMaster University , Hamilton , ON , Canada
| | - Lee R Brooks
- a Department of Brain, Behaviour & Neuroscience , McMaster University , Hamilton , ON , Canada
| | - John G Grundy
- a Department of Brain, Behaviour & Neuroscience , McMaster University , Hamilton , ON , Canada
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LeBarr AN, Grundy JG, Ali M, Shedden JM. Conceptual Organization of Self-representation: A Self-similarity Heuristic for Novel Person Representations. Self and Identity 2015. [DOI: 10.1080/15298868.2015.1072580] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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Grundy JG, Benarroch MFF, Lebarr AN, Shedden JM. Electrophysiological correlates of implicit valenced self-processing in high vs. low self-esteem individuals. Soc Neurosci 2014; 10:100-12. [DOI: 10.1080/17470919.2014.965339] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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Grundy JG, Shedden JM. Support for a history-dependent predictive model of dACC activity in producing the bivalency effect: an event-related potential study. Neuropsychologia 2014; 57:166-78. [PMID: 24686093 DOI: 10.1016/j.neuropsychologia.2014.03.008] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2013] [Revised: 02/28/2014] [Accepted: 03/03/2014] [Indexed: 10/25/2022]
Abstract
In the present study, we examine electrophysiological correlates of factors influencing an adjustment in cognitive control known as the bivalency effect. During task-switching, the occasional presence of bivalent stimuli in a block of univalent trials is enough to elicit a response slowing on all subsequent univalent trials. Bivalent stimuli can be congruent or incongruent with respect to the response afforded by the irrelevant stimulus feature. Here we show that the incongruent bivalency effect, the congruent bivalency effect, and an effect of a simple violation of expectancy are captured at a frontal ERP component (between 300 and 550ms) associated with ACC activity, and that the unexpectedness effect is distinguished from both congruent and incongruent bivalency effects at an earlier component (100-120ms) associated with the temporal parietal junction. We suggest that the frontal component reflects the dACC's role in predicting future cognitive load based on recent history. In contrast, the posterior component may index early visual feature extraction in response to bivalent stimuli that cue currently ongoing tasks; dACC activity may trigger the temporal parietal activity only when specific task cueing is involved and not for simple violations of expectancy.
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Affiliation(s)
- John G Grundy
- Department of Psychology, Neuroscience & Behaviour, McMaster University, 1280 Main Street West, Hamilton, ON, Canada L8S 4K1.
| | - Judith M Shedden
- Department of Psychology, Neuroscience & Behaviour, McMaster University, 1280 Main Street West, Hamilton, ON, Canada L8S 4K1
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Grundy JG, Benarroch MFF, Woodward TS, Metzak PD, Whitman JC, Shedden JM. The bivalency effect in task switching: event-related potentials. Hum Brain Mapp 2011; 34:999-1012. [PMID: 22162123 DOI: 10.1002/hbm.21488] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2011] [Accepted: 09/15/2011] [Indexed: 11/06/2022] Open
Abstract
During task switching, if we occasionally encounter stimuli that cue more than one task (i.e., bivalent stimuli), response slowing is observed on all univalent trials within that block, even when no features overlap with the bivalent stimuli. This observation is known as the bivalency effect. Previous fMRI work (Woodward et al., 2008) clearly suggests a role for the dorsal anterior cingulate cortex (dACC) in the bivalency effect, but the time course remains uncertain. Here, we present the first high-temporal resolution account for the bivalency effect using stimulus-locked event-related potentials. Participants alternated among three simple tasks in six experimental blocks, with bivalent stimuli appearing occasionally in bivalent blocks (blocks 2, 4, and 6). The increased reaction times for univalent stimuli in bivalent blocks demonstrate that these stimuli are being processed differently from univalent stimuli in purely univalent blocks. Frontal electrode sites captured significant amplitude differences associated with the bivalency effect within time windows 100-120 ms, 375-450 ms, and 500-550 ms, which may reflect additional extraction of visual features present in bivalent stimuli (100-120 ms) and suppression of processing carried over from irrelevant cues (375-450 ms and 500-550 ms). Our results support the fMRI findings and provide additional evidence for involvement of the dACC. Furthermore, the bivalency effect dissipated with extended practice both behaviorally and electrophysiologically. These findings are discussed in relation to the differential processing involved in a controlled response style.
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Affiliation(s)
- John G Grundy
- Psychology, Neuroscience and Behaviour, McMaster University, Ontario, Canada
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