TACTILE SPATIAL ACUITY FROM CHILDHOOD INTO ADULTHOOD

Abstract

<p>Measurement of human tactile spatial acuity – the ability to perceive the</p> <p>fine spatial structure of surfaces contacting our fingertips – provides a valuable</p> <p>tool for probing both the peripheral and central nervous system. However,</p> <p>measures of tactile spatial acuity have long been plagued by a prodigious amount</p> <p>of variability present between individuals in their sense of touch. Previously</p> <p>proposed sources of variability include sex, and age; here we propose a novel</p> <p>source of variability – fingertip size. Building upon anatomical research, we</p> <p>hypothesize that mechanoreceptors are more sparsely distributed in larger fingers.</p> <p>In this thesis, I provide empirical and theoretical support for the hypothesis</p> <p>that fingertip growth from childhood into adulthood sets up an apparent sex</p> <p>difference in human tactile spatial acuity during young adulthood (Chapter 2), and</p> <p>also predicts changes in acuity more strongly than does age over development</p> <p>(Chapter 3). To further understand how fingertip size could limit an individual's</p> <p>tactile spatial acuity, we develop an ideal observer model using</p> <p>neurophysiological data collected by other labs (Chapter 4).</p> <p>In summary, this research provides support for a novel source of variability</p> <p>in the sense of touch: one that parsimoniously explains an apparent sex difference,</p> <p>and helps clarify the source of changes in tactile spatial acuity occurring with age</p> <p>during childhood.</p>