Prenatal Androgen and Skills

Официальное название

Prenatal Androgen and Fine Motor Skills and Tactile Discrimination

Обзор

Due to the difficulties and risks of directly measuring prenatal hormone levels, biomarkers that indirectly reflect this exposure are used in research. In this context, the ratio of second to fourth finger length (2D:4D) is widely preferred because it is an easily applicable and non-invasive measurement. Evidence shows that 2D:4D stabilizes from the second trimester of pregnancy onward and exhibits strong sex differences across populations. The 2D:4D ratio is generally lower in men than in women. 2D is more strongly influenced by prenatal estrogen, while 4D is more strongly influenced by prenatal testosterone; this occurs during the first trimester of intrauterine fetal development. To our knowledge, studies examining the relationship between the 2D:4D ratio, an indirect indicator of prenatal androgen exposure, and dexterity and tactile discrimination are limited. Accordingly, the planned study aims to evaluate the relationship between the 2D:4D ratio and fine motor skills and tactile discrimination in healthy young adults.

Подробное описание

Sex hormones experienced during prenatal exposure play a significant role in shaping certain lifelong characteristics by influencing both the physical and neurological development of individuals. The effects of these hormones, particularly on the developing nervous system, contribute to the emergence of behavioral and functional differences. Hand preference and certain behavioral traits in humans have been shown to be related to prenatal hormonal exposure. However, the development of these traits is not limited to hormonal influences alone, but is shaped by the interaction of genetic, environmental, and sociocultural factors. Due to the difficulties and risks of directly measuring prenatal hormone levels, biomarkers that indirectly reflect this exposure are used in research. In this context, the ratio of second to fourth finger length (2D:4D) is widely preferred because it is an easily applicable and non-invasive measurement. The 2D:4D ratio is generally lower in men than in women. 2D is more strongly influenced by prenatal estrogen, while 4D is more strongly influenced by prenatal testosterone; this occurs during the first trimester of intrauterine fetal development. However, whether the 2D:4D ratio is a reliable indicator of prenatal hormonal exposure is still a controversial issue in the literature. Therefore, examining the relationship between the 2D:4D ratio and various biological and functional characteristics remains important. To our knowledge, studies examining the relationship between the 2D:4D ratio, an indirect indicator of prenatal androgen exposure, and dexterity and tactile discrimination are limited. Accordingly, the planned study aims to evaluate the relationship between the 2D:4D ratio and fine motor skills and tactile discrimination in healthy young adults. It is hypothesized that prenatal hormonal exposure may indirectly shape finger morphology and receptor distribution by affecting skin and nervous system development, which may be a determining factor in tactile sensitivity and dexterity.

Вмешательства

• Другое Digit Ratio
  The second (2D) and fourth (4D) finger lengths of the participants will be measured separately in both hands by a physiotherapist with over thirteen years of clinical experience.
• Поведенческое Fine motor skills
  Hand dexterity will be assessed using the Purdue Pegboard Test. The test will be administered according to standard procedure with participants seated at a table. Participants will be asked to place the pegs into the corresponding holes as quickly and accurately as possible within a specified time (30 seconds).
• Поведенческое Tactile Discrimination
  To perform the 2-point discrimination tests, the Baseline® two-point discriminator will be used. Measurements will be applied to the distal phalangeal pulp of the index finger on both hands while participants are seated in a comfortable position with their eyes closed.

Первичные конечные точки

• 2-point discrimination test [Срок оценки: 12 months]
• Digit Ratio [Срок оценки: 12 months]
• Fine motor skills [Срок оценки: 12 months]

Критерии участия

Критерии включения

• Healthy individuals aged 18-40
• Having sufficient visual and auditory function to understand and administer the test,
• Voluntary agreement to participate in the study and providing informed consent.

Критерии исключения

• Individuals with any musculoskeletal pathology,
• History of upper extremity trauma,
• Individuals diagnosed with metabolic, neurological, or genetic diseases,
• Individuals with a history of hand surgery within the last 6 months,
• Pregnancy or breastfeeding.

Критерии приведены из реестра в оригинале (на английском). Окончательную оценку соответствия проводит исследовательский центр.

Здоровые добровольцы: Да

Дизайн исследования

Модель наблюдения

Другое

Центры проведения

Turkey (Türkiye) · 1 центр

• Nigde Omer Halisdemir University — Niğde

Публикации

• Butovskaya M, Adam Y, Batsevich V, Shackelford TK, Fink B. Associations between 2D:4D from direct and radiographic measurements with handgrip strength in young adult Tuvans. Early Hum Dev. 2024 Jun;193:106037. doi: 10.1016/j.earlhumdev.2024.106037. Epub 2024 May 8. PMID 38743999
• Fink B, Manning JT, Neave N, Tan U. Second to fourth digit ratio and hand skill in Austrian children. Biol Psychol. 2004 Nov;67(3):375-84. doi: 10.1016/j.biopsycho.2004.03.012. PMID 15294393

Идентификаторы

NCT: NCT07627113 · Androgen and Skills

Первоисточники (государственные реестры)

• ClinicalTrials.gov (NIH, США)

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