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Bacali C, Constantiniuc M, Craciun A, Popa D. Assessment of the Vertical Dimension of Occlusion Using Palm Width and Finger Length. MEDICINA (KAUNAS, LITHUANIA) 2024; 60:1526. [PMID: 39336567 PMCID: PMC11433983 DOI: 10.3390/medicina60091526] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/21/2024] [Revised: 09/13/2024] [Accepted: 09/16/2024] [Indexed: 09/30/2024]
Abstract
Background and Objectives: The vertical dimension of occlusion's (VDO) assessment is a highly important issue in the everyday dentist's practice. Patients with unstable occlusion, lost occlusal stops, extensive tooth loss in the lateral area, or complete edentulism need a proper assessment of the VDO before the prosthetic restoration is carried out. Subjective and objective methods were used over time for the restoration of VDO. The study aimed to investigate the possible correlation between finger length, palm width and the vertical dimension of occlusion. Materials and Methods: Assessment of the VDO for 236 subjects, Romanian and French dental students, was performed using the Willis Bite Gauge. The left hand of the subjects was scanned using a flat-bed scanner, and then measurements of palm width and finger length were carried out for each subject. Comparison between VDO values and finger length/palm width was conducted using one-way ANOVA and Student t-Test. Results: Higher VDO average values were found in French subjects compared with Romanian students. The same results were found according to gender; in both female and male subjects, lower values of VDO were found in the Romanian group. Higher values were obtained for women within each group when comparing to men. Statistically significant correlations of the analyzed parameters and VDO values were found. Higher statistical correlations of the studied variables were found for men compared to women in both groups. The highest statistical correlation was obtained between the VDO and the palm width measured at the fingerbase, followed by the middle finger length. Conclusions: The results showed the highest statistical correlation between the vertical dimension of occlusion and the palm width measured at the fingers' base. Statistical correlations were also found between the VDO and the middle finger length. Simple formulas using finger length/palm width can be used for a rapid VDO determination.
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Affiliation(s)
- Cecilia Bacali
- Department of Prosthodontics and Dental Materials, "Iuliu Hațieganu" University of Medicine and Pharmacy, 400006 Cluj-Napoca, Romania
| | - Mariana Constantiniuc
- Department of Prosthodontics and Dental Materials, "Iuliu Hațieganu" University of Medicine and Pharmacy, 400006 Cluj-Napoca, Romania
| | - Antarinia Craciun
- Department of Prosthodontics and Dental Materials, "Iuliu Hațieganu" University of Medicine and Pharmacy, 400006 Cluj-Napoca, Romania
| | - Daniela Popa
- Department of Prosthodontics and Dental Materials, "Iuliu Hațieganu" University of Medicine and Pharmacy, 400006 Cluj-Napoca, Romania
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Haroon TM, C. Tiwari R, Mahajan A, Polavarapu J, Kandregula M, Loganathan J, Varma P. Occlusal vertical dimension and its association with length of thumb: An original research. J Pharm Bioallied Sci 2022; 14:S304-S306. [PMID: 36110776 PMCID: PMC9469270 DOI: 10.4103/jpbs.jpbs_770_21] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2021] [Revised: 12/10/2021] [Accepted: 12/16/2021] [Indexed: 11/17/2022] Open
Abstract
Introduction: Establishing an accurate vertical dimension at occlusal (VDO) is a challenge. Hence, we aim to find the association between the VDO and the Thumb Length (TL). Materials and Methods: We piloted an observational study by evaluating the VDO and the TL among the Dravidian and Aryan ethnicities with 200 volunteers. The comparisons were made applying the “linear regression analysis” to find the correlation of both. Results: We observed that a strong and positive relation was established for the two parameters of VDO and TL for both the ethnicities. Conclusion: We can suggest from our study that the thumb length can be used as an aid for the occlusal vertical dimension estimation.
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Turan Ş, Boysan M, Tarakçıoğlu MC, Sağlam T, Yassa A, Bakay H, Demirel ÖF, Tosun M. 2D:4D Digit Ratios in Adults with Gender Dysphoria: A Comparison to Their Unaffected Same-Sex Heterosexual Siblings, Cisgender Heterosexual Men, and Cisgender Heterosexual Women. ARCHIVES OF SEXUAL BEHAVIOR 2021; 50:885-895. [PMID: 33694048 DOI: 10.1007/s10508-021-01938-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/30/2018] [Revised: 01/26/2021] [Accepted: 01/30/2021] [Indexed: 06/12/2023]
Abstract
We compared gender dysphoria (GD) patients and their same-sex siblings in terms of their 2D:4D ratios, which may reflect prenatal exposure to androgen, one of the possible etiological mechanisms underlying GD. Sixty-eight GD patients (46 Female-to-Male [FtM]; 22 Male-to-Female [MtF]), 68 siblings (46 sisters of FtMs; 22 brothers of MtFs), and 118 heterosexual controls (62 female; 56 male) were included in the study. FtMs were gynephilic and MtFs were androphilic. We found that 2D:4D ratios in the both right hand (p < .001) and the left hand (p = .003) were lower in male controls than in female controls. Regarding right hands, FtM GD patients had lower 2D:4D ratios than female controls (p < .001) but their ratios did not differ from those of their sisters or male controls. FtM GD patients had no significant difference in their left-hand 2D:4D ratios compared to their sisters or female and male controls. While there was no significant difference in right hands between FtM's sisters and male controls, left-hand 2D:4D ratios were significantly higher in FtM's sisters (p = .017). MtF GD patients had lower right-hand 2D:4D ratios than female controls (p <.001), but their right-hand ratios did not differ from those of their brothers and male controls. There was no significant difference in left-hand 2D:4D ratios between MtF GD patients, and their brothers, or female and male controls. FtM GD patients showed significantly masculinized right-hand 2D:4D ratios, while there was no evidence of feminization in MtF GD patients.
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Affiliation(s)
- Şenol Turan
- Department of Psychiatry, Cerrahpaşa School of Medicine, Istanbul University-Cerrahpaşa, Cerrahpaşa-Fatih, 34098, Istanbul, Turkey.
| | - Murat Boysan
- Department of Psychology, Faculty of Social Sciences and Humanities, Ankara Social Sciences University, Ankara, Turkey
| | - Mahmut Cem Tarakçıoğlu
- Department of Child and Adolescent Psychiatry, Cerrahpaşa School of Medicine, Istanbul University-Cerrahpaşa, Istanbul, Turkey
| | - Tarık Sağlam
- Department of Psychiatry, Halil Şıvgın Çubuk State Hospital, Ankara, Turkey
| | - Ahmet Yassa
- Department of Psychiatry, Yozgat State Hospital, Yozgat, Turkey
| | - Hasan Bakay
- Department of Psychiatry, Nizip State Hospital, Gaziantep, Turkey
| | - Ömer Faruk Demirel
- Department of Psychiatry, Cerrahpaşa School of Medicine, Istanbul University-Cerrahpaşa, Cerrahpaşa-Fatih, 34098, Istanbul, Turkey
| | - Musa Tosun
- Department of Psychiatry, Cerrahpaşa School of Medicine, Istanbul University-Cerrahpaşa, Cerrahpaşa-Fatih, 34098, Istanbul, Turkey
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4
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Richards G, Beking T, Kreukels BPC, Geuze RH, Beaton AA, Groothuis T. An examination of the influence of prenatal sex hormones on handedness: Literature review and amniotic fluid data. Horm Behav 2021; 129:104929. [PMID: 33454315 DOI: 10.1016/j.yhbeh.2021.104929] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/15/2020] [Revised: 12/30/2020] [Accepted: 12/31/2020] [Indexed: 01/27/2023]
Abstract
Competing theories have posited roles for foetal androgen exposure in the development of human handedness. However, due to practical and ethical considerations, few studies have used hormonal measures to examine this possibility. The current paper reviews this literature and reveals a generally inconsistent pattern of results. We also present data from a longitudinal study of prenatal sex hormone exposure and subsequent handedness. More specifically, we examine correlations between testosterone and estradiol measured from second trimester amniotic fluid and hand preference (Dutch language version of the Edinburgh Handedness Inventory) and hand skill asymmetry (pegboard task) measured at 15 years of age. Prenatal sex hormone exposure was not associated with the direction of hand preference in either males or females. However, in females, high levels of prenatal testosterone were associated with weaker lateralisation of hand skill, and high levels of prenatal estradiol were associated with weaker hand preference. In addition, high levels of prenatal testosterone were associated with increased task duration (i.e., slow hand speed) for the right and left hands of males. The pattern of results observed here is not entirely consistent with any of the main theories linking sex hormones with handedness, suggesting that an association between these variables may be more complex than initially thought.
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Affiliation(s)
- Gareth Richards
- Newcastle University, School of Psychology, Ridley Building 1, Queen Victoria Road, Newcastle upon Tyne NE1 7RU, UK; University of Cambridge, Autism Research Centre, Department of Psychiatry, Douglas House, 18b Trumpington Road, Cambridge CB2 8AH, UK.
| | - Tess Beking
- University of Groningen, Faculty of Behavioural and Social Sciences, Department Clinical & Developmental Neuropsychology, Grote Kruisstraat 2/1, 9712 TS Groningen, the Netherlands; Amsterdam University Medical Center, location VUmc, Department of Medical Psychology, Center of Expertise on Gender Dysphoria, PO Box 7057, 1007 MB Amsterdam, the Netherlands; University of Groningen, Groningen Institute for Evolutionary Life Sciences, Nijenborgh 7, 9747 AG Groningen, the Netherlands
| | - Baudewijntje P C Kreukels
- Amsterdam University Medical Center, location VUmc, Department of Medical Psychology, Center of Expertise on Gender Dysphoria, PO Box 7057, 1007 MB Amsterdam, the Netherlands
| | - Reint H Geuze
- University of Groningen, Faculty of Behavioural and Social Sciences, Department Clinical & Developmental Neuropsychology, Grote Kruisstraat 2/1, 9712 TS Groningen, the Netherlands
| | - Alan A Beaton
- Swansea University, Department of Psychology, School of Human & Health Sciences, Swansea SA2 8PP, UK; Aberystwyth University, Department of Psychology, Aberystwyth SY23 3UX, UK
| | - Ton Groothuis
- University of Groningen, Groningen Institute for Evolutionary Life Sciences, Nijenborgh 7, 9747 AG Groningen, the Netherlands
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Richards G, Medland SE, Beaton AA. Digit ratio (2D:4D) and handedness: A meta-analysis of the available literature. Laterality 2021; 26:421-484. [PMID: 33517845 DOI: 10.1080/1357650x.2020.1862141] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
The Geschwind-Behan-Galaburda and sexual differentiation models predict an association between elevated foetal androgen exposure and left-handedness whereas the callosal hypothesis predicts the opposite. We present a meta-analysis of correlations between handedness and digit ratio (2D:4D), a putative marker of prenatal testosterone. Left-handedness predicted low (male-typical) right-hand digit ratio (R2D:4D), high (female-typical) left-hand digit ratio (L2D:4D), and low R2D:4D-L2D:4D directional asymmetry (D[R-L]). Effect sizes were extremely small and not moderated by sex or method of measuring handedness or 2D:4D. The same general pattern was observed after excluding the very large study (110,329 males, 90,412 females) of Manning and Peters ([2009]. Digit ratio (2D:4D) and hand preference for writing in the BBC Internet Study. Laterality: Asymmetries of Body, Brain and Cognition, 14(5), 528-540. doi:10.1080/13576500802637872); however, no significant effects for R2D:4D were observed once these samples were removed. The results do not confirm any theory linking prenatal androgens with handedness, so we speculate they instead reflect the mechanical action of writing causing subtle changes in the musculature and/or fat pads of the fingers. Gripping a pen/pencil might cause an increase in 2D relative to 4D (and/or decrease in 4D relative to 2D) resulting in higher ratios on the writing-hand; furthermore, this could differ between left- and right-handers due to writing in the left-to-right direction (as in English) having asymmetrical effects depending on which hand is used.
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Affiliation(s)
- Gareth Richards
- School of Psychology, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, UK.,Autism Research Centre, Department of Psychiatry, University of Cambridge, Cambridge, UK.,Centre for Research on Play in Education, Development & Learning, Faculty of Education, University of Cambridge, Cambridge, UK
| | - Sarah E Medland
- Psychiatric Genetics, QIMR Berghofer Medical Research Institute, Brisbane, Australia.,School of Psychology, University of Queensland, St Lucia, Australia.,School of Psychology and Counselling, Queensland University of Technology, Brisbane, Australia
| | - Alan A Beaton
- Department of Psychology, School of Human & Health Sciences, Swansea University, Swansea, UK.,Department of Psychology, Aberystwyth University, Aberystwyth, UK
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Fedato A, Silva-Gago M, Terradillos-Bernal M, Alonso-Alcalde R, Martín-Guerra E, Bruner E. Hand morphometrics, electrodermal activity, and stone tools haptic perception. Am J Hum Biol 2019; 32:e23370. [PMID: 31837092 DOI: 10.1002/ajhb.23370] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2019] [Revised: 11/21/2019] [Accepted: 11/27/2019] [Indexed: 11/06/2022] Open
Abstract
OBJECTIVES Tool use requires integration among sensorial, biomechanical, and cognitive factors. Taking into account the importance of tool use in human evolution, changes associated with the genus Homo are to be expected in all these three aspects. Haptics is based on both tactile and proprioceptive feedbacks, and it is associated with emotional reactions. Previous analyses have suggested a difference between males and females, and during haptic exploration of different typologies of stone tools. Here, we analyze the correlation between electrodermal reactions during stone tool handling and hand morphology to provide evidence of possible allometric factors shared by males and females. METHODS Electrodermal analysis was used to investigate some specific parameters involved in these reactions, such as changes in the level of attention and arousal. We analyzed the responses of 46 right-handed adults to 20 distinct stone tools while blindfolded. RESULTS Females have smaller hands and a wider range of electrodermal reactions. Within males and females, hand diameters and general hand size do not correlate with the degree of electrodermal level and response. CONCLUSIONS Sex differences in electrodemal reaction during stone tool handling are apparently not due to the effect of hand size or proportions. Differences between males and females are better interpreted as real sex differences, either due to a biological or cultural influences. Hand size does not influence the degree of arousal or attention during tool exploration, suggesting that other factors trigger individual reactions. These results add to a general cognitive approach on hand-tool evolution and tool sensing.
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Affiliation(s)
- Annapaola Fedato
- Programa de paleobiología, Centro Nacional de Investigación sobre la Evolución Humana, Burgos, Spain
| | - María Silva-Gago
- Programa de paleobiología, Centro Nacional de Investigación sobre la Evolución Humana, Burgos, Spain
| | | | | | | | - Emiliano Bruner
- Programa de paleobiología, Centro Nacional de Investigación sobre la Evolución Humana, Burgos, Spain
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7
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Schmitz J, Metz GA, Güntürkün O, Ocklenburg S. Beyond the genome—Towards an epigenetic understanding of handedness ontogenesis. Prog Neurobiol 2017; 159:69-89. [DOI: 10.1016/j.pneurobio.2017.10.005] [Citation(s) in RCA: 46] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2017] [Revised: 09/18/2017] [Accepted: 10/26/2017] [Indexed: 12/13/2022]
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8
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Huber SE, Lenz B, Kornhuber J, Müller CP. Prenatal androgen-receptor activity has organizational morphological effects in mice. PLoS One 2017; 12:e0188752. [PMID: 29176856 PMCID: PMC5703447 DOI: 10.1371/journal.pone.0188752] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2017] [Accepted: 11/12/2017] [Indexed: 11/19/2022] Open
Abstract
Prenatal sex hormones exert organizational effects. It has been suggested that prenatal sex hormones affect adult morphological parameters, such as the finger length. Especially the second-to-fourth finger length (2D:4D) ratio has been implicated to be modified when exposed to higher androgen levels in utero. Here we show in a mouse model that experimental manipulation of the prenatal androgen level, by blocking the androgen receptor with flutamide or activating the androgen receptor with dihydrotestosterone (DHT), leads to changes in the length of the fingers of all paws in males and females. In addition to that, also total paw length and the 2D:4D ratio was affected. In males treated with DHT, the 2D:4D ratio was increased, while flutamide-treatment in females led to a reduced 2D:4D ratio. We also measured other parameters, such as head size, body length and tail length and demonstrate that body morphology is affected by prenatal androgen exposure with more prominent effects in females. Another factor that is thought to be influenced by early androgens is handedness. We tested mice for handedness, but did not find a significant effect of the prenatal treatment. These findings demonstrate that prenatal androgen activity is involved in the development of body morphology and might be a useful marker for prenatal androgen exposure.
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Affiliation(s)
- Sabine E. Huber
- Department of Psychiatry and Psychotherapy, University Clinic, Friedrich-Alexander University Erlangen-Nürnberg (FAU), Erlangen, Germany
| | - Bernd Lenz
- Department of Psychiatry and Psychotherapy, University Clinic, Friedrich-Alexander University Erlangen-Nürnberg (FAU), Erlangen, Germany
| | - Johannes Kornhuber
- Department of Psychiatry and Psychotherapy, University Clinic, Friedrich-Alexander University Erlangen-Nürnberg (FAU), Erlangen, Germany
| | - Christian P. Müller
- Department of Psychiatry and Psychotherapy, University Clinic, Friedrich-Alexander University Erlangen-Nürnberg (FAU), Erlangen, Germany
- * E-mail:
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Papadatou-Pastou M, Martin M. Cerebral laterality for language is related to adult salivary testosterone levels but not digit ratio (2D:4D) in men: A functional transcranial Doppler ultrasound study. BRAIN AND LANGUAGE 2017; 166:52-62. [PMID: 28088127 DOI: 10.1016/j.bandl.2016.12.002] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/14/2015] [Revised: 11/07/2016] [Accepted: 12/12/2016] [Indexed: 06/06/2023]
Abstract
The adequacy of three competing theories of hormonal effects on cerebral laterality are compared using functional transcranial Doppler sonography (fTCD). Thirty-three adult males participated in the study (21 left-handers). Cerebral lateralization was measured by fTCD using an extensively validated word generation task. Adult salivary testosterone (T) and cortisol (C) concentrations were measured by luminescence immunoassay and prenatal T exposure was indirectly estimated by the somatic marker of 2nd to 4th digit length ratio (2D:4D). A significant quadratic relationship between degree of cerebral laterality for language and adult T concentrations was observed, with enhanced T levels for strong left hemisphere dominance and strong right hemisphere dominance. No systematic effects on laterality were found for cortisol or 2D:4D. Findings suggest that higher levels of T are associated with a relatively attenuated degree of interhemispheric sharing of linguistic information, providing support for the callosal and the sexual differentiation hypotheses rather than the Geschwind, Behan and Galaburda (GBG) hypothesis.
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Affiliation(s)
- Marietta Papadatou-Pastou
- Cognition and Health Research Group, Department of Experimental Psychology, University of Oxford, 9 South Parks Road, Oxford OX1 3UD, UK.
| | - Maryanne Martin
- Cognition and Health Research Group, Department of Experimental Psychology, University of Oxford, 9 South Parks Road, Oxford OX1 3UD, UK.
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Stolten M, Ledet E, Dotiwala A, Luk E, Sartor O. Alternative Digit Ratios and Their Relationship to Prostate Cancer. Clin Genitourin Cancer 2016; 14:149-52. [DOI: 10.1016/j.clgc.2015.11.005] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2015] [Revised: 11/01/2015] [Accepted: 11/04/2015] [Indexed: 10/22/2022]
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11
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Hudson JM, Hodgson JC. Is digit ratio (2D:4D) a reliable pointer to speech laterality? Behav Brain Res 2016; 301:258-61. [DOI: 10.1016/j.bbr.2015.12.042] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2015] [Revised: 12/19/2015] [Accepted: 12/25/2015] [Indexed: 11/29/2022]
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12
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Left with Raging Hormones. Laterality 2016. [DOI: 10.1016/b978-0-12-801239-0.00005-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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13
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Hope D, Bates TC, Dykiert D, Der G, Deary IJ. More symmetrical children have faster and more consistent choice reaction times. Dev Psychol 2015; 51:524-32. [PMID: 25664831 PMCID: PMC4378532 DOI: 10.1037/a0038756] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Greater cognitive ability in childhood is associated with increased longevity, and speedier reaction time (RT) might account for much of this linkage. Greater bodily symmetry is linked to both higher cognitive test scores and faster RTs. It is possible, then, that differences in bodily system integrity indexed by symmetry may underlie the associations of RT and intelligence with increased longevity. However, RT and symmetry have seldom been examined in the same study, and never in children. Here, in 2 large samples aged 4 to 15 (combined n = 856), we found that more symmetrical children had significantly faster mean choice RT and less variability in RT. These associations of faster and less variable RT with greater symmetry early in life raise the possibility that the determinants of longevity in part originate in processes influencing bodily system integrity early in the life-course.
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Affiliation(s)
- David Hope
- Centre for Cognitive Ageing and Cognitive Epidemiology, University of Edinburgh
| | - Timothy C Bates
- Centre for Cognitive Ageing and Cognitive Epidemiology, University of Edinburgh
| | - Dominika Dykiert
- Centre for Cognitive Ageing and Cognitive Epidemiology, University of Edinburgh
| | - Geoff Der
- Centre for Cognitive Ageing and Cognitive Epidemiology, University of Edinburgh
| | - Ian J Deary
- Centre for Cognitive Ageing and Cognitive Epidemiology, University of Edinburgh
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14
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Basnet BB, Parajuli PK, Singh RK, Suwal P, Shrestha P, Baral D. An anthropometric study to evaluate the correlation between the occlusal vertical dimension and length of the thumb. Clin Cosmet Investig Dent 2015; 7:33-9. [PMID: 25678817 PMCID: PMC4322952 DOI: 10.2147/ccide.s75872] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
BACKGROUND Establishment of proper occlusal vertical dimension (OVD) is one of the important tasks for successful prosthodontic therapy. An ideal method for determining OVD in terms of cost, time, and instrument requirements has been sought in prosthodontics by various investigators. However, no such single method has been formulated. In the current anthropometric study, the relationship of the length of the thumb to the OVD was tested in two ethnic groups of Nepal, Aryans, and Mongoloids. The result of this study can be useful in determining proper OVD in edentulous patients. AIMS AND OBJECTIVES The primary aim of the present study was to evaluate the correlation between the length of the thumb and OVD in Aryan and Mongoloid ethnic groups. The secondary aim was to compare the correlation between OVD and other anatomic measurements (eye-ear distance and pupil-to-rima oris distance) in these ethnicities. MATERIALS AND METHODS The OVD, thumb length, eye-ear distance and distance between pupil of eye and rima oris were measured in a total of 500 adult dentulous volunteers. The correlation between OVD and thumb length as well as other anatomic measurements was checked with Pearson's product moment correlation coefficient. Linear regression analysis was performed to determine the relationship of OVD to the length of the thumb. RESULTS The thumb length was significantly (P≤0.05) correlated with strong and positive values (Pearson's coefficient =0.874 in the whole population, 0.826 in Aryans, and 0.944 in Mongoloids). Regression analysis showed that thumb length was significantly related to OVD in both ethnic groups. CONCLUSION Within the limitations of the present study, the result implies that thumb length can be used as an adjunct for establishing OVD in the edentulous patients.
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Affiliation(s)
- Bishal Babu Basnet
- Department of Prosthodontics, BP Koirala Institute of Health Sciences, Dharan, Nepal
| | | | - Raj Kumar Singh
- Department of Prosthodontics, BP Koirala Institute of Health Sciences, Dharan, Nepal
| | - Pramita Suwal
- Department of Prosthodontics, BP Koirala Institute of Health Sciences, Dharan, Nepal
| | - Pragya Shrestha
- Department of Prosthodontics, BP Koirala Institute of Health Sciences, Dharan, Nepal
| | - Dharanidhar Baral
- Department of Prosthodontics, BP Koirala Institute of Health Sciences, Dharan, Nepal
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Alterations in sensitivity to estrogen, dihydrotestosterone, and xenogens in B-lymphocytes from children with autism spectrum disorder and their unaffected twins/siblings. J Toxicol 2013; 2013:159810. [PMID: 24363669 PMCID: PMC3836453 DOI: 10.1155/2013/159810] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2013] [Revised: 09/17/2013] [Accepted: 09/17/2013] [Indexed: 11/26/2022] Open
Abstract
It has been postulated that androgen overexposure in a susceptible person leads to excessive brain masculinization and the autism spectrum disorder (ASD) phenotype. In this study, the responses to estradiol (E2), dihydrotestosterone (DHT), and dichlorodiphenyldichloroethylene (DDE) on B-lymphocytes from ASD subjects and controls are compared. B cells were obtained from 11 ASD subjects, their unaffected fraternal twins, and nontwin siblings. Controls were obtained from a different cell bank. Lactate dehydrogenase (LDH) and sodium 2,3-bis(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide (XTT) reduction levels were measured after incubation with different concentrations of E2, DHT, and DDE. XTT/LDH ratio, representative of mitochondria number per cell, was calculated. E2, DHT, and DDE all cause “U”-shaped growth curves, as measured by LDH levels. ASD B cells show less growth depression compared to siblings and controls (P < 0.01). They also have reduced XTT/LDH ratios (P < 0.01) when compared to external controls, whereas siblings had values of XTT/LDH between ASD and external controls. B-lymphocytes from people with ASD exhibit a differential response to E2, DHT, and hormone disruptors in regard to cell growth and mitochondrial upregulation when compared to non-ASD siblings and external controls. Specifically, ASD B-lymphocytes show significantly less growth depression and less mitochondrial upregulation when exposed to these effectors. A mitochondrial deficit in ASD individuals is implied.
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Speech dominance is a better predictor of functional brain asymmetry than handedness: a combined fMRI word generation and behavioral dichotic listening study. Neuropsychologia 2012; 51:91-7. [PMID: 23149380 DOI: 10.1016/j.neuropsychologia.2012.11.002] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2012] [Revised: 10/09/2012] [Accepted: 11/01/2012] [Indexed: 11/21/2022]
Abstract
An unresolved issue in behavioral studies of hemispheric asymmetry is why both left-handers and right-handers show a right ear advantage at the group level. In the present study we screened left-handers for left- versus right-hemisphere speech dominance with fMRI by comparing right versus left hemisphere frontal lobe activity (in Broca's area) in a silent word generation task. A left hemisphere dominant right-handed control group was included as well. All participants took part in a dichotic listening task with consonant-vowel syllables. The results showed that left-handers and right-handers with left-hemisphere speech dominance showed a right ear advantage. However, the left-handers with right hemisphere speech dominance had a left ear advantage. Thus, at the group level the direction of the ear advantage in dichotic listening was predicted by language dominance but not by hand preference. At the individual level, the dichotic task we used showed more variability than the fMRI results. Further research will have to indicate whether this is a feature inherent to dichotic listening, or whether the variability is due to alternative explanations such as a more bilateral representation of speech perception compared to speech production.
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Lenz B, Müller CP, Kornhuber J. Alcohol dependence in same-sex and opposite-sex twins. J Neural Transm (Vienna) 2012; 119:1561-4. [PMID: 23104613 DOI: 10.1007/s00702-012-0907-7] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2012] [Accepted: 10/16/2012] [Indexed: 11/24/2022]
Abstract
Males with a female co-twin are more likely to become alcohol-dependent than males with a male co-twin. According to the twin testosterone transfer model, this finding can be interpreted as indirect evidence for a role of prenatal testosterone in alcohol dependence.
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Affiliation(s)
- Bernd Lenz
- Department of Psychiatry and Psychotherapy, Friedrich-Alexander-University of Erlangen-Nuremberg, Schwabachanlage 6-10, 91054, Erlangen, Germany.
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Jackson CJ, Hobman EV, Jimmieson NL, Martin R. Do left and right asymmetries of hemispheric preference interact with attention to predict local and global performance in applied tasks? Laterality 2012; 17:647-72. [PMID: 22332788 DOI: 10.1080/1357650x.2011.615125] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
Abstract
Many cognitive neuroscience studies show that the ability to attend to and identify global or local information is lateralised between the two hemispheres in the human brain; the left hemisphere is biased towards the local level, whereas the right hemisphere is biased towards the global level. Results of two studies show attention-focused people with a right ear preference (biased towards the left hemisphere) are better at local tasks, whereas people with a left ear preference (biased towards the right hemisphere) are better at more global tasks. In a third study we determined if right hemisphere-biased followers who attend to global stimuli are likely to have a stronger relationship between attention and globally based supervisor ratings of performance. Results provide evidence in support of this hypothesis. Our research supports our model and suggests that the interaction between attention and lateral preference is an important and novel predictor of work-related outcomes.
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Affiliation(s)
- Chris J Jackson
- The School of Management, The University of New South Wales, Sydney, NSW, Australia.
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Lenz B, Müller CP, Stoessel C, Sperling W, Biermann T, Hillemacher T, Bleich S, Kornhuber J. Sex hormone activity in alcohol addiction: integrating organizational and activational effects. Prog Neurobiol 2011; 96:136-63. [PMID: 22115850 DOI: 10.1016/j.pneurobio.2011.11.001] [Citation(s) in RCA: 100] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2011] [Revised: 11/03/2011] [Accepted: 11/08/2011] [Indexed: 01/06/2023]
Abstract
There are well-known sex differences in the epidemiology and etiopathology of alcohol dependence. Male gender is a crucial risk factor for the onset of alcohol addiction. A directly modifying role of testosterone in alcohol addiction-related behavior is well established. Sex hormones exert both permanent (organizational) and transient (activational) effects on the human brain. The sensitive period for these effects lasts throughout life. In this article, we present a novel early sex hormone activity model of alcohol addiction. We propose that early exposure to sex hormones triggers structural (organizational) neuroadaptations. These neuroadaptations affect cellular and behavioral responses to adult sex hormones, sensitize the brain's reward system to the reinforcing properties of alcohol and modulate alcohol addictive behavior later in life. This review outlines clinical findings related to the early sex hormone activity model of alcohol addiction (handedness, the second-to-fourth-finger length ratio, and the androgen receptor and aromatase) and includes clinical and preclinical literature regarding the activational effects of sex hormones in alcohol drinking behavior. Furthermore, we discuss the role of the hypothalamic-pituitary-adrenal and -gonadal axes and the opioid system in mediating the relationship between sex hormone activity and alcohol dependence. We conclude that a combination of exposure to sex hormones in utero and during early development contributes to the risk of alcohol addiction later in life. The early sex hormone activity model of alcohol addiction may prove to be a valuable tool in the development of preventive and therapeutic strategies.
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Affiliation(s)
- Bernd Lenz
- Department of Psychiatry and Psychotherapy, Friedrich-Alexander-University of Erlangen-Nuremberg, Germany.
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Wright L, Hardie SM. “Not ready to sort it yet”: Revised reinforcement sensitivity theory (rRST) predicts left-handed behavioural inhibition during a manual sorting task. Laterality 2011; 16:753-67. [DOI: 10.1080/1357650x.2010.521752] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Kornhuber J, Erhard G, Lenz B, Kraus T, Sperling W, Bayerlein K, Biermann T, Stoessel C. Low digit ratio 2D:4D in alcohol dependent patients. PLoS One 2011; 6:e19332. [PMID: 21547078 PMCID: PMC3081847 DOI: 10.1371/journal.pone.0019332] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2011] [Accepted: 03/26/2011] [Indexed: 11/23/2022] Open
Abstract
The ratio of the lengths of the second and fourth finger (2D∶4D) has been
described as reflecting the degree of prenatal androgen exposure in humans.
2D∶4D is smaller for males than females and is associated with traits such
as left-handedness, physical aggression, attention-deficit-hyperactivity
disorder and a genetic polymorphism of the androgen receptor. All of these
traits are known to be correlated to the vulnerability for alcohol dependency.
We therefore hypothesized low 2D∶4D in patients with alcohol dependency.
In the present study on 131 patients suffering from alcohol dependency and 185
healthy volunteers, we found that alcohol dependent patients had smaller
2D∶4D ratios compared to controls with preserved sexual dimorphism but
with reduced right-left differences. The detection of alcohol dependency based
on 2D∶4D ratios was most accurate using the right hand of males
(ROC-analysis: AUC 0.725, sensitivity 0.667, specificity 0.723). These findings
provide novel insights into the role of prenatal androgen exposure in the
development of alcohol dependency and for the use of 2D∶4D as a possible
trait marker in identifying patients with alcohol dependency.
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Affiliation(s)
- Johannes Kornhuber
- Department of Psychiatry and Psychotherapy, Friedrich-Alexander University of Erlangen-Nuremberg, Erlangen, Germany.
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Beaton AA, Rudling N, Kissling C, Taurines R, Thome J. Digit ratio (2D:4D), salivary testosterone, and handedness. Laterality 2011; 16:136-55. [DOI: 10.1080/13576500903410369] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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Vuoksimaa E, Peter Eriksson CJ, Pulkkinen L, Rose RJ, Kaprio J. Decreased prevalence of left-handedness among females with male co-twins: evidence suggesting prenatal testosterone transfer in humans? Psychoneuroendocrinology 2010; 35:1462-72. [PMID: 20570052 PMCID: PMC2950868 DOI: 10.1016/j.psyneuen.2010.04.013] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/27/2009] [Revised: 04/19/2010] [Accepted: 04/23/2010] [Indexed: 10/19/2022]
Abstract
Studies of singletons suggest that right-handed individuals may have higher levels of testosterone than do left-handed individuals. Prenatal testosterone levels are hypothesised to be especially related to handedness formation. In humans, female members from opposite-sex twin pairs may experience elevated level of prenatal exposure to testosterone in their intrauterine environment shared with a male. We tested for differences in rates of left-handedness/right-handedness in female twins from same-sex and opposite-sex twin pairs. Our sample consisted of 4736 subjects, about 70% of all Finnish twins born in 1983-1987, with information on measured pregnancy and birth related factors. Circulating testosterone and estradiol levels at age 14 were available on 771 and 744 of these twins, respectively. We found significantly (p=.006) lower prevalence of left-handedness in females from opposite-sex pairs (5.3%) compared to females from same-sex pairs (8.6%). The circulating levels of neither testosterone nor estradiol related to handedness in either females or males. Nor were there differences in circulating testosterone or estradiol levels between females from opposite-sex and same-sex twin pairs. Birth and pregnancy related factors for which we had information were unrelated to handedness. Our results are difficult to fully explain by postnatal factors, but they offer support to theory that relates testosterone to formation of handedness, and in a population-based sample, are suggestive of effects of prenatal testosterone transfer.
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Affiliation(s)
- Eero Vuoksimaa
- Department of Public Health, University of Helsinki, Finland.
| | - C. J. Peter Eriksson
- Department of Alcohol, Drugs and Addiction, National Institute for Health and Welfare, Helsinki, Finland
| | - Lea Pulkkinen
- Department of Psychology, University of Jyväskylä, Finland
| | - Richard J. Rose
- Department of Public Health, University of Helsinki, Finland, Department of Psychological and Brain Sciences, Indiana University, Bloomington, USA
| | - Jaakko Kaprio
- Department of Public Health, University of Helsinki, Finland, Department of Mental Health and Substance Abuse Services, National Institute for Health and Welfare, Helsinki, Finland, Institute for Molecular Medicine, University of Helsinki, Helsinki, Finland
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Abstract
It has been reported that there is a high proportion of left-handers among top athletes in different sports. In this study, the goal was to examine the rate of left-handedness in the top wrestlers at the world championships for achievement by left-handed wrestlers. The rate of left-handedness was higher in wrestlers with medal honors compared to wrestlers without medals for both men and women. The winning numbers and match degrees were higher in the left-handed wrestlers than in both right- and mixed-handed wrestlers among top international wrestlers.
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Increased ratio of 2nd to 4th digit (2D:4D) in schizophrenia. Psychiatry Res 2010; 176:8-12. [PMID: 20083312 DOI: 10.1016/j.psychres.2009.08.023] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/20/2009] [Revised: 08/14/2009] [Accepted: 08/20/2009] [Indexed: 01/18/2023]
Abstract
Sex differences in the onset, epidemiology, clinical presentation and neuropathology of schizophrenia suggest that sexual dimorphism in brain development may be relevant to pathogenesis. Sex hormones, in particular testosterone, are considered to be crucial in brain development, but few investigations have examined the potential role of prenatal testosterone in schizophrenia. In this study, we examined a retrospective marker of prenatal testosterone release - 2D:4D finger length ratio (2D:4D), the relative length of 2nd to 4th digit, in 64 Asian patients with schizophrenia and 64 sex-matched controls. No significant difference in mean finger lengths was present, however 2D:4D ratio was significantly different between patients and controls. The effect was primarily seen in males consistent with a 'less masculinised' pattern and hypotheses suggesting that schizophrenia may be associated with an abnormality in prenatal circulating testosterone.
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Hönekopp J, Schuster M. A meta-analysis on 2D:4D and athletic prowess: Substantial relationships but neither hand out-predicts the other. PERSONALITY AND INDIVIDUAL DIFFERENCES 2010. [DOI: 10.1016/j.paid.2009.08.009] [Citation(s) in RCA: 82] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
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Hernandez CE, Harding JE, Oliver MH, Bloomfield FH, Held SD, Matthews LR. Effects of litter size, sex and periconceptional ewe nutrition on side preference and cognitive flexibility in the offspring. Behav Brain Res 2009; 204:82-7. [DOI: 10.1016/j.bbr.2009.05.019] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2009] [Revised: 05/11/2009] [Accepted: 05/16/2009] [Indexed: 10/20/2022]
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Voracek M, Pum U, Dressler SG. Investigating digit ratio (2D:4D) in a highly male-dominated occupation: the case of firefighters. Scand J Psychol 2009; 51:146-56. [PMID: 19954495 DOI: 10.1111/j.1467-9450.2009.00758.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Second-to-fourth digit ratio (2D:4D), a widely studied putative marker for masculinization through prenatal androgen exposure, is lower (more masculinized) in athletes than in general population controls, and athletes with lower 2D:4D have higher sporting success. Occupations differ markedly in perceived masculinity and actual maleness (sex ratios), but these givens have not yet been picked up and utilized in 2D:4D research. Accordingly, this study extended existing accounts on 2D:4D in athletes to a novel approach: 2D:4D and possible relationships to a variety of candidate variables (demographic, fertility-related, psychological, and other) were investigated in firefighters, a highly male-dominated occupation. Contrary to expectation, 2D:4D in firefighters (N = 134) was not lower than in local male population controls. Lower 2D:4D corresponded to lower service ranks. Replicating previous findings either unequivocally or partly, lower 2D:4D was associated with larger family size, later sibling position, left-handedness, and higher scores in the disinhibition component of sensation seeking. Not replicating prior evidence, 2D:4D was unrelated to body-mass index, offspring sex ratio, and sporting performance level. Novel findings included low 2D:4D in those with low relationship satisfaction and in cigarette smokers, especially among heavy smokers. Absolute finger length, a positive correlate of pubertal-adolescent androgen levels, was also considered. This marker showed negative associations with relationship consensus and satisfaction and positive ones with perceived quality of relationship alternatives and the experience seeking component of sensation seeking. The merits of this additional marker, relative to 2D:4D, for supplementing studies of possible sex-hormonal effects on personality and directions for future inquiry along these lines are discussed.
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Affiliation(s)
- Martin Voracek
- Department of Basic Psychological Research, School of Psychology, University of Vienna, Liebiggasse 5, Rm 03-46, A-1010, Vienna, Austria.
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30
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Voracek M, Loibl LM. Scientometric analysis and bibliography of digit ratio (2D:4D) research, 1998-2008. Psychol Rep 2009; 104:922-56. [PMID: 19708418 DOI: 10.2466/pr0.104.3.922-956] [Citation(s) in RCA: 95] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
A scientometric analysis of modern research on the second-to-fourth digit ratio (2D:4D), a widely studied putative marker for prenatal androgen action, is presented. In early 2009, this literature totalled more than 300 publications and, since its initiation in 1998, has grown at a rate slightly faster than linear. Key findings included evidence of publication bias and citation bias, incomplete coverage and outdatedness of existing reviews, and a dearth of meta-analyses in this field. 2D:4D research clusters noticeably in terms of researchers, institutions, countries, and journals involved. Although 2D:4D is an anthropometric trait, most of the research has been conducted at psychology departments, not anthropology departments. However, 2D:4D research has not been predominantly published in core and specialized journals of psychology, but rather in more broadly scoped journals of the behavioral sciences, biomedical social sciences, and neurosciences. Total citation numbers of 2D:4D papers for the most part were not larger than their citation counts within 2D:4D research, indicating that until now, only a few 2D:4D studies have attained broader interest outside this specific field. Comparative citation analyses show that 2D:4D research presently is commensurate in size and importance to evolutionary psychological jealousy research, but has grown faster than the latter field. In contrast, it is much smaller and has spread more slowly than research about the Implicit Association Test Fifteen conjectures about anticipated trends in 2D:4D research are outlined, appendixed by a first-time bibliography of the entirety of the published 2D:4D literature.
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Affiliation(s)
- Martin Voracek
- Department of Basic Psychological Research, School of Psychology, University of Vienna, Liebiggasse 5, Rm 03-46, A-1010 Vienna, Austria.
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31
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Bourne VJ, Gray DL. Hormone exposure and functional lateralisation: examining the contributions of prenatal and later life hormonal exposure. Psychoneuroendocrinology 2009; 34:1214-21. [PMID: 19375867 DOI: 10.1016/j.psyneuen.2009.03.010] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/16/2008] [Revised: 03/12/2009] [Accepted: 03/12/2009] [Indexed: 10/20/2022]
Abstract
An increasing amount of research has shown a relationship between hormonal exposure and functional lateralisation. In this study different sources of hormonal exposure were examined: prenatal exposure, estimated using the 2D:4D ratio, and later life exposure through examining the effects of hormone replacement therapy. In addition to considering multiple sources of hormonal exposure, three tests of functional lateralisation were used: two versions of the chimeric faces test, one using positive emotion and the other using negative emotion, and the landmark task. The same effects were found across all three measures of lateralisation. Lower 2D:4D ratios, which indicate high levels of prenatal testosterone exposure, were associated with stronger right hemisphere dominance. Later life hormonal exposure was not found to be associated with any of the lateralisation measures. This finding suggests a relationship between prenatal hormonal exposure and brain organisation.
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Affiliation(s)
- Victoria J Bourne
- School of Psychology, University of Dundee, Park Place, Dundee, DD1 4HN, UK.
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Manning JT, Peters M. Digit ratio (2D:4D) and hand preference for writing in the BBC Internet Study. Laterality 2009; 14:528-40. [DOI: 10.1080/13576500802637872] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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33
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Voracek M. Who wants to believe? Associations between digit ratio (2D:4D) and paranormal and superstitious beliefs. PERSONALITY AND INDIVIDUAL DIFFERENCES 2009. [DOI: 10.1016/j.paid.2009.01.051] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
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34
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Bescós R, Esteve M, Porta J, Mateu M, Irurtia A, Voracek M. Prenatal programming of sporting success: Associations of digit ratio (2D:4D), a putative marker for prenatal androgen action, with world rankings in female fencers. J Sports Sci 2009; 27:625-32. [PMID: 19308788 DOI: 10.1080/02640410802707029] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
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Voracek M. The Relation of Digit Ratio (2D:4D) and Absolute Finger Length to Pavlovian Temperament Dimensions. Psychol Rep 2008; 103:783-92. [DOI: 10.2466/pr0.103.3.783-792] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
The associations of digit ratio (2D:4D), a likely marker for prenatal androgen exposure, and absolute finger length, a likely marker for postnatal androgen exposure, with self-reports on three Pavlovian temperament dimensions (strength of excitation, strength of inhibition, and mobility of nervous processes) were investigated in a sample of 84 men and 114 women. In men, left-hand 2D:4D was weakly, but significantly, negatively associated with strength of inhibition, and also weakly negatively, but not significantly, associated with the two other temperament dimensions. These effects were absent for men's right-hand 2D:4D. Finger lengths of both hands in men were weakly, but significantly, positively associated with mobility of nervous processes scores. All associations for women were negligible. Both prenatal and postnatal androgen action may contribute to small amounts of individual differences in Pavlovian temperament dimensions in men but apparently not in women.
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Jackson CJ. When avoidance leads to approach: how ear preference interacts with neuroticism to predict disinhibited approach. Laterality 2008; 13:333-73. [PMID: 18592433 DOI: 10.1080/13576500802063053] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
A series of eight studies focuses on how the avoidance system represented by neuroticism can lead to disinhibited approach tendencies. Based on research which argues that hemispheric preferences predispose the left hemisphere to fast action goal formation, and contralateral pathways between ear and brain, it is proposed that (a) people with a right ear preference will engage in fast action goal formation and (b) disinhibited approach results from neurotic people who reduce anxiety by means of fast action goal formation. Study 1 provides evidence from telesales operators of a link between self-rated ear preference and objective ear preference and provides evidence that disinhibited approach is predicted by a neuroticismxear preference interaction. Studies 2, 3, and 4 provide evidence that ear preference is related to other measures of objective aural preference and action goal formation. Studies 5, 6, 7, and 8 provide evidence that the neuroticismxear preference interaction predicts a variety of different disinhibited approach tendencies.
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Affiliation(s)
- Chris J Jackson
- Australian School of Business, UNSW, Sydney, NSW, Australia.
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37
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Ypsilanti A, Ganou M, Koidou I, Grouios G. Digit ratio (2D:4D) in individuals with intellectual disability: Investigating the role of testosterone in the establishment of cerebral lateralisation. Laterality 2008; 13:527-44. [DOI: 10.1080/13576500802117164] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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38
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Gillam L, McDonald R, Ebling FJP, Mayhew TM. Human 2D (index) and 4D (ring) finger lengths and ratios: cross-sectional data on linear growth patterns, sexual dimorphism and lateral asymmetry from 4 to 60 years of age. J Anat 2008; 213:325-35. [PMID: 18624829 DOI: 10.1111/j.1469-7580.2008.00940.x] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
Human 2D : 4D ratios (measures of the relative lengths of index and ring fingers) attract considerable research interest because they exhibit sexual dimorphism and are associated with various morphological, physiological and behavioural traits as well as sporting abilities and medical conditions. In an attempt to identify potential confounding factors in such studies, we have examined how relative and absolute digit lengths vary with gender and tested whether they are influenced by age, right-left asymmetry and hand preference. Participants between 4 and 60 years of age were recruited from local educational sites. Hand photocopies and calliper measurement were used to obtain digit lengths. We employed linear regression analysis to examine the growth trajectories of individual digits, analyses of variance to isolate main and interaction effects of age, gender and hand preference, and paired t-tests to identify lateral asymmetries. Both digits exhibited biphasic growth with an early growth phase followed by a stable length phase. Digits in females attained their maximum length about 2.2 years (dextral subjects) or 5.1 years (sinistral subjects) earlier than those in males. Sexual dimorphism in 2D : 4D ratios was apparent by 4 years of age and age changes in ratios depended on gender, side and hand preference. Relative and absolute lengths displayed age, gender, hand-preference and age x gender interaction effects. Lengths tended to be greater in females in younger subjects and greater in males in older subjects. Ratios tended to be greater in sinistral subjects. In dextral subjects, significant lateral asymmetries in 2D lengths were seen at all ages but asymmetries in males and 4D lengths seemed to be age-dependent. We conclude that age, lateral asymmetry and hand preference are potential confounding factors and that future study designs should take account of these as well as other known confounders such as ethnicity, birth order, menstrual cycle phase and sexual preference.
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Affiliation(s)
- L Gillam
- School of Biomedical Sciences, Queen's Medical Centre, University of Nottingham, Nottingham NG7 2UH, United Kingdom
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Abstract
Digit ratio (2D:4D), a putative marker for prenatal androgen levels, and absolute finger length, a marker for pubertal androgen action, were not associated with wearing of wedding rings in a sample of 150 male and 199 female married individuals. This failure to replicate associations previously reported by Manning was true for both men and women, self-reported and spousal ring-wearing behavior, and one's own and spousal 2D:4D or absolute finger lengths. Supplemental findings included sex differences and age effects in the prevalence of wearing wedding rings (more frequent in women and the younger than in men and the older) and a sex bias when ring-wearing behavior within couples was discordant (men more frequently did not wear their wedding ring when their wives did than vice versa). Discussed are implications of the current findings and directions for future research into possible associations of 2D:4D with other aspects of body ornamentation.
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40
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VORACEK MARTIN. THE RELATION OF DIGIT RATIO (2D:4D) AND ABSOLUTE FINGER LENGTH TO PAVLOVIAN TEMPERAMENT DIMENSIONS. Psychol Rep 2008. [DOI: 10.2466/pr0.103.7.783-792] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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