Functional Asymmetry of the Brain: An Innovative Test for LeftHandedness and Leftness in Basic Neuroscience Research and Neurorehabilitation

Abstract

Introduction: Fast and high-quality detection of leftyness can be very informative in pedagogy, professional selection, medicine. To do this, it is necessary to develop a test that should be informative, simple, concise, quick to conduct and calculate, not requiring special equipment, combining questions and tasks, revealing mainly persistent and unambiguous manifestations of leftyness in various aspects such as biographical, motor, sensory, mental ones. Goal: to develop a universal test that provides reliable and rapid detection of signs of leftyness in healthy and sick subjects. Materials and Methods: according to the developed protocol for leftyness detecting, consisting of 13 questions and samples, 210 people were studied, including 100 healthy persons and 110 patients randomly selected during neuropsychiatric or neuropsychological examination. Results: test providing and protocol completion were fast, easily accessible both in the study of healthy and patients. When testing the primary protocol, it was found that: a) patients older than 30 years were less likely to report the presence of signs of leftyness, most of them preferred the right hand; b) women, compared with men, were more likely to report the presence of prophetic dreams and other variants of foresight; c) familial leftyness was more often found in patients compared with healthy persons d) according to most of the studied signes (7 out of 13), the largest proportion of patients with leftyness was found in patients with functional mental illnesses; e) significant correlations were found between biographical leftyness and left-handedness, as well as between left-handedness and ear leftyness. Based on the conducted research, a new improved protocol of test for the express detection of signs of leftyness (TEDSL) was created. Conclusion: The modified TEDSL protocol developed as a result of this work is ready for use in further studies of various contingents of healthy and patients with various psychopathological symptoms.