1
|
Prevalence of Common Alleles of Some Stress Resilience Genes among Adolescents Born in Different Periods Relative to the Socioeconomic Crisis of the 1990s in Russia. Curr Issues Mol Biol 2022; 45:51-65. [PMID: 36661490 PMCID: PMC9857244 DOI: 10.3390/cimb45010004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2022] [Revised: 12/13/2022] [Accepted: 12/19/2022] [Indexed: 12/24/2022] Open
Abstract
Social stress is common among people and is considered one of the causes of the declining birth rate. Predisposition to stress and stress-induced disorders is largely determined genetically. We hypothesized that due to differences in stress resistance, carriers of different genetic variants of genes associated with stress resilience and stress-induced diseases may have dissimilar numbers of offspring under conditions of long-term social stress. To test this hypothesis, a comparative analysis of frequencies of seven common polymorphic regions [exon 3 variable number of tandem repeats (VNTR) of the DRD4 gene, rs4680 of COMT, STin2 VNTR and the 5-HTTLPR (rs774676466) insertion/deletion polymorphism of SLC6A4, rs4570625 of TPH2, rs6265 of BDNF, and rs258747 of NR3C1] was performed on standardized groups of randomly selected adolescents born before, during, and after severe socioeconomic deprivation (the crisis of the 1990s in Russia). There were significant differences in frequencies of "long" alleles of the DRD4 gene (p = 0.020, χ2 = 5.492) and rs4680 (p = 0.022, χ2 = 5.289) in the "crisis" group as compared to the combined "noncrisis" population. It is possible that the dopaminergic system had an impact on the successful adaptation of a person to social stress.
Collapse
|
2
|
Kanarik M, Grimm O, Mota NR, Reif A, Harro J. ADHD co-morbidities: A review of implication of gene × environment effects with dopamine-related genes. Neurosci Biobehav Rev 2022; 139:104757. [PMID: 35777579 DOI: 10.1016/j.neubiorev.2022.104757] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2020] [Revised: 06/25/2022] [Accepted: 06/26/2022] [Indexed: 02/07/2023]
Abstract
ADHD is a major burden in adulthood, where co-morbid conditions such as depression, substance use disorder and obesity often dominate the clinical picture. ADHD has substantial shared heritability with other mental disorders, contributing to comorbidity. However, environmental risk factors exist but their interaction with genetic makeup, especially in relation to comorbid disorders, remains elusive. This review for the first time summarizes present knowledge on gene x environment (GxE) interactions regarding the dopamine system. Hitherto, mainly candidate (GxE) studies were performed, focusing on the genes DRD4, DAT1 and MAOA. Some evidence suggest that the variable number tandem repeats in DRD4 and MAOA may mediate GxE interactions in ADHD generally, and comorbid conditions specifically. Nevertheless, even for these genes, common variants are bound to suggest risk only in the context of gender and specific environments. For other polymorphisms, evidence is contradictory and less convincing. Particularly lacking are longitudinal studies testing the interaction of well-defined environmental with polygenic risk scores reflecting the dopamine system in its entirety.
Collapse
Affiliation(s)
- Margus Kanarik
- Chair of Neuropsychopharmacology, Institute of Chemistry, University of Tartu, Ravila 14A Chemicum, 50411 Tartu, Estonia
| | - Oliver Grimm
- Department of Psychiatry, Psychosomatic Medicine and Psychotherapy, University Hospital, Goethe University, Frankfurt, Germany
| | - Nina Roth Mota
- Department of Human Genetics, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, the Netherlands; Department of Psychiatry, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Andreas Reif
- Department of Psychiatry, Psychosomatic Medicine and Psychotherapy, University Hospital, Goethe University, Frankfurt, Germany
| | - Jaanus Harro
- Chair of Neuropsychopharmacology, Institute of Chemistry, University of Tartu, Ravila 14A Chemicum, 50411 Tartu, Estonia; Psychiatry Clinic, North Estonia Medical Centre, Paldiski Road 52, 10614 Tallinn, Estonia.
| |
Collapse
|
3
|
Koob AO, Ballantyne S, Levesque AA, Qureshi AA, Congdon S. DRD4 Allele Frequency as a Lab Exercise in Neuroscience and Genetics Courses. JOURNAL OF UNDERGRADUATE NEUROSCIENCE EDUCATION : JUNE : A PUBLICATION OF FUN, FACULTY FOR UNDERGRADUATE NEUROSCIENCE 2021; 20:A1-A10. [PMID: 35540948 PMCID: PMC9053424] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 04/03/2021] [Revised: 08/17/2021] [Accepted: 08/24/2021] [Indexed: 06/14/2023]
Abstract
DNA segments with variable number tandem repeats (VNTR) serve as a model for students to learn DNA extraction and polymerase chain reaction (PCR) techniques in biology laboratory courses from the high school to the graduate level. Because of a growing interest in the neurosciences among undergraduates, we have developed a PCR exercise with a focus on the nervous system and behavior, with the aim of inspiring students from all aspects of the neurosciences to appreciate the central dogma and neurogenetics. DRD4 was a good candidate to provide a lab exercise that would be more engaging than VNTR analysis of a non-coding segment. DRD4 encodes for the dopamine D4 receptor and has been controversially associated with 'novelty seeking' or 'wanderlust' behavior. DRD4 has three common variants of the 48 bp sequence on exon 3, easily differentiated through gel electrophoresis. The 2 repeat (2R), 4 repeat (4R) and 7 repeat (7R) of the 48 bp sequence are the most common alleles. The 7R sequences result in the expressed dopamine D4 receptor having less affinity for dopamine binding, which was proposed to be the reason individuals engage in 'novelty seeking' behavior, to increase dopamine release to facilitate more binding to the receptor. Here we demonstrate an enjoyable and simple two lab sequence to analyze DRD4 genotypes that is appropriate for neuroscience and genetics courses.
Collapse
Affiliation(s)
- Andrew O. Koob
- Biology Department, University of Hartford, West Hartford, CT 06117
| | - Scott Ballantyne
- Biology Department, University of Wisconsin – River Falls, River Falls, WI 54022
| | - Aime A. Levesque
- Biology Department, University of Hartford, West Hartford, CT 06117
| | - Amber A. Qureshi
- Biology Department, University of Wisconsin – River Falls, River Falls, WI 54022
| | - Sean Congdon
- Biology Department, University of Hartford, West Hartford, CT 06117
| |
Collapse
|
4
|
Leukel C, Schümann D, Kalisch R, Sommer T, Bunzeck N. Dopamine Related Genes Differentially Affect Declarative Long-Term Memory in Healthy Humans. Front Behav Neurosci 2020; 14:539725. [PMID: 33328916 PMCID: PMC7673390 DOI: 10.3389/fnbeh.2020.539725] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2020] [Accepted: 09/04/2020] [Indexed: 11/22/2022] Open
Abstract
In humans, monetary reward can promote behavioral performance including response times, accuracy, and subsequent recognition memory. Recent studies have shown that the dopaminergic system plays an essential role here, but the link to interindividual differences remains unclear. To further investigate this issue, we focused on previously described polymorphisms of genes affecting dopaminergic neurotransmission: DAT1 40 base pair (bp), DAT1 30 bp, DRD4 48 bp, and cannabinoid receptor type 1 (CNR1). Specifically, 669 healthy humans participated in a delayed recognition memory paradigm on two consecutive days. On the first day, male vs. female faces served as cues predicting an immediate monetary reward upon correct button presses. Subsequently, participants performed a remember/know recognition memory task on the same day and 1 day later. As predicted, reward increased accuracy and accelerated response times, which were modulated by DAT 30 bp. However, reward did not promote subsequent recognition memory performance and there was no interaction with any genotype tested here. Importantly, there were differential effects of genotype on declarative long-term memory independent of reward: (a) DAT1 40 bp was linked to the quality of memory with a more pronounced difference between recollection and familiarity in the heterozygous and homozygous 10-R as compared to homozygous 9-R; (b) DAT1 30 bp was linked to memory decay, which was most pronounced in homozygous 4-R; (c) DRD4 48 bp was linked to overall recognition memory with higher performance in the short allele group; and (d) CNR1 was linked to overall memory with reduced performance in the homozygous short group. These findings give new insights into how polymorphisms, which are related to dopaminergic neuromodulation, differentially affect long-term recognition memory performance.
Collapse
Affiliation(s)
- Carla Leukel
- Department of Psychology, University of Lübeck, Lübeck, Germany
| | - Dirk Schümann
- Department of Systems Neuroscience, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Raffael Kalisch
- Department of Systems Neuroscience, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.,Neuroimaging Center (NIC), Focus Program Translational Neuroscience, Johannes Gutenberg University Medical Center, Mainz, Germany.,Leibniz Institute for Resilience Research (LIR), Mainz, Germany
| | - Tobias Sommer
- Department of Systems Neuroscience, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Nico Bunzeck
- Department of Psychology, University of Lübeck, Lübeck, Germany.,Department of Systems Neuroscience, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.,Center of Brain, Behavior and Metabolism (CBBM), University of Lübeck, Lübeck, Germany
| |
Collapse
|
5
|
González-Arancibia C, Urrutia-Piñones J, Illanes-González J, Martinez-Pinto J, Sotomayor-Zárate R, Julio-Pieper M, Bravo JA. Do your gut microbes affect your brain dopamine? Psychopharmacology (Berl) 2019; 236:1611-1622. [PMID: 31098656 DOI: 10.1007/s00213-019-05265-5] [Citation(s) in RCA: 77] [Impact Index Per Article: 15.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/03/2018] [Accepted: 04/26/2019] [Indexed: 02/08/2023]
Abstract
Increasing evidence shows changes in gut microbiota composition in association with psychiatric disorders, including anxiety and depression. Moreover, it has been reported that perturbations in gut microbe diversity and richness influence serotonergic, GABAergic, noradrenergic, and dopaminergic neurotransmission. Among these, dopamine is regarded as a main regulator of cognitive functions such as decision making, attention, memory, motivation, and reward. In this work, we will highlight findings that link alterations in intestinal microbiota and dopaminergic neurotransmission, with a particular emphasis on the mesocorticolimbic circuit, which is involved in reward to natural reinforcers, as well as abuse substances. For this, we reviewed evidence from studies carried out on germ-free animals, or in rodents subjected to intestinal dysbiosis using antibiotics, and also through the use of probiotics. All this evidence strongly supports that the microbiota-gut-brain axis is key to the physiopathology of several neuropsychiatric disorders involving those where dopaminergic neurotransmission is compromised. In addition, the gut microbiota appears as a key player when it comes to proposing novel strategies to the treatment of these psychiatric conditions.
Collapse
Affiliation(s)
- Camila González-Arancibia
- Grupo de NeuroGastroBioquímica, Laboratorio de Química Biológica y Bioquímica de Sistemas, Instituto de Química, Facultad de Ciencias, Pontificia Universidad Católica de Valparaíso, Av. Universidad 330, Curauma, Valparaíso, Región de Valparaíso, Chile.,Laboratorio de Neuroquímica y Neurofarmacología, Centro de Neurobiología y Fisiopatología Integrativa, Instituto de Fisiología, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso, Chile.,Programa de Doctorado en Ciencias mención Neurociencia, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso, Chile
| | - Jocelyn Urrutia-Piñones
- Grupo de NeuroGastroBioquímica, Laboratorio de Química Biológica y Bioquímica de Sistemas, Instituto de Química, Facultad de Ciencias, Pontificia Universidad Católica de Valparaíso, Av. Universidad 330, Curauma, Valparaíso, Región de Valparaíso, Chile.,Programa de Doctorado en Ciencias mención Neurociencia, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso, Chile
| | - Javiera Illanes-González
- Grupo de NeuroGastroBioquímica, Laboratorio de Química Biológica y Bioquímica de Sistemas, Instituto de Química, Facultad de Ciencias, Pontificia Universidad Católica de Valparaíso, Av. Universidad 330, Curauma, Valparaíso, Región de Valparaíso, Chile.,Programa de Doctorado en Ciencias mención Neurociencia, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso, Chile
| | - Jonathan Martinez-Pinto
- Laboratorio de Neuroquímica y Neurofarmacología, Centro de Neurobiología y Fisiopatología Integrativa, Instituto de Fisiología, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso, Chile
| | - Ramón Sotomayor-Zárate
- Laboratorio de Neuroquímica y Neurofarmacología, Centro de Neurobiología y Fisiopatología Integrativa, Instituto de Fisiología, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso, Chile
| | - Marcela Julio-Pieper
- Grupo de NeuroGastroBioquímica, Laboratorio de Química Biológica y Bioquímica de Sistemas, Instituto de Química, Facultad de Ciencias, Pontificia Universidad Católica de Valparaíso, Av. Universidad 330, Curauma, Valparaíso, Región de Valparaíso, Chile
| | - Javier A Bravo
- Grupo de NeuroGastroBioquímica, Laboratorio de Química Biológica y Bioquímica de Sistemas, Instituto de Química, Facultad de Ciencias, Pontificia Universidad Católica de Valparaíso, Av. Universidad 330, Curauma, Valparaíso, Región de Valparaíso, Chile.
| |
Collapse
|
6
|
Intellectual Investment, Dopaminergic Gene Variation, and Life Events: A Critical Examination. PERSONALITY NEUROSCIENCE 2018; 1:e3. [PMID: 32435725 PMCID: PMC7219688 DOI: 10.1017/pen.2018.2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Accepted: 01/17/2018] [Indexed: 11/05/2022]
Abstract
Need for Cognition (NFC) and Openness to Ideas are intellectual investment traits that are characterized by a tendency to seek out, engage in and enjoy effortful cognitive activity. Little, however, is known about the extent to which they are influenced by genetic and environmental factors. With the present contribution, we aim at furthering our knowledge on the mechanisms underlying intellectual investment traits by following-up on a recent investigation of the role of dopaminergic gene variation in intellectual investment. Employing a standard approach that relied on null-hypothesis significance testing, we found that, first, two dopaminergic genetic variants interacted in modulating individual differences in NFC, but not in Openness to Ideas; that, second, negative life events played a role in the modulation of Openness to Ideas, but not of NFC; and that, third, negative life events as assessed using another measure were only marginally related to Openness to Ideas while positive life events were associated with both Openness to Ideas and NFC, with the latter effect being also dependent on DRD4 exon III genotype. However, employing a Bayesian approach, the assumption of a genetic effect on investment traits was overall not supported, while the assumption of a role of positive life events in the modulation of investment traits could be confirmed, with a tentative increment in the prediction of NFC by adding an interaction of positive life events and DRD4 variation to the main effect of positive life events. Our findings underscore the importance to use different approaches in the field of personality neuroscience. To gain deeper insight into the basis of personality traits does not only require to consider genetic as well as environmental influences and their interplay, but also requires more differentiated statistical analyses that can at least in part tackle the often inconsistent findings in this field.
Collapse
|
7
|
Pekcanlar Akay A, Eresen Yazıcıoğlu Ç, Alşen Güney S, Özek Erkuran H, Kızıldağ S, Baykara B, Özyurt G, Yıldırımcan Kadıçeşme Ş, Miral S, İnal Emiroğlu N. Allele frequencies of dopamine D4 receptor gene (DRD4) and Catechol-O-methyltransferase (COMT) Val158Met polymorphism are associated with methylphenidate response in adolescents with attention deficit/hyperactivity disorder: a case control preliminary study. PSYCHIAT CLIN PSYCH 2018. [DOI: 10.1080/24750573.2017.1418134] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/18/2022] Open
Affiliation(s)
- Aynur Pekcanlar Akay
- Department of Child and Adolescent Psychiatry, Dokuz Eylul University, Izmir, Turkey
| | | | - Sevay Alşen Güney
- Department of Child and Adolescent Psychiatry, Dokuz Eylul University, Izmir, Turkey
| | - Handan Özek Erkuran
- Deparment of Child and Adolescent Psychiatry, Child Psychiatry Specialist, Dr. Behçet Uz Pediatrics and Pediatric Surgery Training Hospital, Izmir, Turkey
| | - Sefa Kızıldağ
- Department of Molecular Biology and Genetics, Dokuz Eylul University, Izmir, Turkey
| | - Burak Baykara
- Department of Child and Adolescent Psychiatry, Dokuz Eylul University, Izmir, Turkey
| | - Gonca Özyurt
- Department of Child and Adolescent Psychiatry, Katip Çelebi University Medical Faculty, Izmir, Turkey
| | | | - Süha Miral
- Department of Child and Adolescent Psychiatry, Dokuz Eylul University, Izmir, Turkey
| | | |
Collapse
|
8
|
KANG Y, CHONG X, WU N. Autism Spectrum Disorders early warning: Occurrence, development and influencing factors of joint attention and empathy. ACTA ACUST UNITED AC 2018. [DOI: 10.3724/sp.j.1042.2018.01223] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
|
9
|
Lundwall RA, Dannemiller JL, Goldsmith HH. Genetic associations with reflexive visual attention in infancy and childhood. Dev Sci 2015; 20. [PMID: 26613685 DOI: 10.1111/desc.12371] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2014] [Accepted: 08/28/2015] [Indexed: 12/11/2022]
Abstract
This study elucidates genetic influences on reflexive (as opposed to sustained) attention in children (aged 9-16 years; N = 332) who previously participated as infants in visual attention studies using orienting to a moving bar (Dannemiller, 2004). We investigated genetic associations with reflexive attention measures in infancy and childhood in the same group of children. The genetic markers (single nucleotide polymorphisms and variable number tandem repeats on the genes APOE, BDNF, CHRNA4, COMT, DRD4, HTR4, IGF2, MAOA, SLC5A7, SLC6A3, and SNAP25) are related to brain development and/or to the availability of neurotransmitters such as acetylcholine, dopamine, or serotonin. This study shows that typically developing children have differences in reflexive attention associated with their genes, as we found in adults (Lundwall, Guo & Dannemiller, 2012). This effort to extend our previous findings to outcomes in infancy and childhood was necessary because genetic influence may differ over the course of development. Although two of the genes that were tested in our adult study (Lundwall et al., 2012) were significant in either our infant study (SLC6A3) or child study (DRD4), the specific markers tested differed. Performance on the infant task was associated with SLC6A3. In addition, several genetic associations with an analogous child task occurred with markers on CHRNA4, COMT, and DRD4. Interestingly, the child version of the task involved an interaction such that which genotype group performed poorer on the child task depended on whether we were examining the higher or lower infant scoring group. These findings are discussed in terms of genetic influences on reflexive attention in infancy and childhood.
Collapse
|
10
|
Xie Z, Maddox WT, McGeary JE, Chandrasekaran B. The C957T polymorphism in the dopamine receptor D₂ gene modulates domain-general category learning. J Neurophysiol 2015; 113:3281-90. [PMID: 25761959 DOI: 10.1152/jn.01005.2014] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2014] [Accepted: 03/10/2015] [Indexed: 11/22/2022] Open
Abstract
Adaptive learning from reward and punishment is vital for human survival. Striatal and frontal dopaminergic activities are associated with adaptive learning. For example, the C957T single nucleotide polymorphism of the dopamine receptor D2 (DRD2) gene alters striatal D2 receptor availability and affects individuals' adaptive learning ability. Specifically, individuals with the T/T genotype, which is associated with higher striatal D2 availability, show enhanced learning from negative outcomes. Prior work examining DRD2 genetic variability has focused primarily on frontally mediated reflective learning that is under effortful, conscious control. However, less is known about a more automatic, striatally mediated reflexive learning. Here we examined the extent to which this polymorphism differentially influences reflective and reflexive learning across visual and auditory modalities. We employed rule-based (RB) and information-integration (II) category learning paradigms that target reflective and reflexive learning, respectively. Results revealed an advantage in II category learning but poorer RB category learning in T/T homozygotes. The pattern of results was consistent across sensory modalities. These findings suggest that this DRD2 polymorphism exerts opposite influences on domain-general frontally mediated reflective learning and striatally mediated reflexive learning.
Collapse
Affiliation(s)
- Zilong Xie
- Department of Communication Sciences & Disorders, The University of Texas at Austin, Austin, Texas
| | - W Todd Maddox
- Department of Psychology, The University of Texas at Austin, Austin, Texas
| | - John E McGeary
- Division of Behavioral Genetics, Rhode Island Hospital, Providence, Rhode Island; Brown University, Providence, Rhode Island; and Psychologist, Providence Veterans Affairs Medical Center, Providence, Rhode Island
| | - Bharath Chandrasekaran
- Department of Communication Sciences & Disorders, The University of Texas at Austin, Austin, Texas;
| |
Collapse
|
11
|
Dopamine receptor D4 (DRD4) gene modulates the influence of informational masking on speech recognition. Neuropsychologia 2014; 67:121-31. [PMID: 25497692 DOI: 10.1016/j.neuropsychologia.2014.12.013] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2014] [Revised: 12/09/2014] [Accepted: 12/10/2014] [Indexed: 12/30/2022]
Abstract
Listeners vary substantially in their ability to recognize speech in noisy environments. Here we examined the role of genetic variation on individual differences in speech recognition in various noise backgrounds. Background noise typically varies in the levels of energetic masking (EM) and informational masking (IM) imposed on target speech. Relative to EM, release from IM is hypothesized to place greater demand on executive function to selectively attend to target speech while ignoring competing noises. Recent evidence suggests that the long allele variant in exon III of the DRD4 gene, primarily expressed in the prefrontal cortex, may be associated with enhanced selective attention to goal-relevant high-priority information even in the face of interference. We investigated the extent to which this polymorphism is associated with speech recognition in IM and EM conditions. In an unscreened adult sample (Experiment 1) and a larger screened replication sample (Experiment 2), we demonstrate that individuals with the DRD4 long variant show better recognition performance in noise conditions involving significant IM, but not in EM conditions. In Experiment 2, we also obtained neuropsychological measures to assess the underlying mechanisms. Mediation analysis revealed that this listening condition-specific advantage was mediated by enhanced executive attention/working memory capacity in individuals with the long allele variant. These findings suggest that DRD4 may contribute specifically to individual differences in speech recognition ability in noise conditions that place demands on executive function.
Collapse
|