title: Analysis of blink rate patterns in normal subjects.
abstract: The present study measured the normal blink rate (BR) variations in relation to behavioral tasks in 150 healthy volunteers (70 males and 80 females; aged 35.9 +/- 17.9 years, range 5-87 years). The subjects were videotaped in a standard setting while performing three different tasks: resting quietly, reading a short passage, talking freely. The mean BR was computed during each task; the data were compared by means of analysis of variance and Student's t tests. Mean BR at rest was 17 blinks/min, during conversation it increased to 26, and it was as low as 4.5 while reading. As compared with rest, BR decreased by -55.08% while reading (p < 1 x 10(-15)) and increased by 99.70% during conversation (p < 1 x 10(-9)). As compared with reading, BR increased during conversation by 577.8% (p < 1 x 10(-17). The distribution curves were highly reproducible in each task. The best curve fit was represented by a log-normal distribution, with the upper tail of each curve having a normal distribution. Eye color and eyeglass wearing did not influence BR. Women had higher BR than men just while reading. No age-related differences were found. The most common BR pattern was conversation > rest > reading, which occurred in 101 subjects (67.3%); 34 subjects (22.7%) had the pattern rest > conversation > reading; 12 (8.0%) had the pattern conversation > reading > rest. This study identified three normal behavioral BR patterns and showed that BR is more influenced by cognitive processes than by age, eye color, or local factors. The present findings provide a normal reference for the analysis of BR in movement disorders such as dystonia or tics.
authors.affiliation: Istituto di Neurologia, Università Cattolica del Sacro Cuore, Roma, Italy.
authors.forename: A R
authors.initials: AR
authors.lastname: Bentivoglio
authors.forename: S B
authors.initials: SB
authors.lastname: Bressman
authors.forename: E
authors.initials: E
authors.lastname: Cassetta
authors.forename: D
authors.initials: D
authors.lastname: Carretta
authors.forename: P
authors.initials: P
authors.lastname: Tonali
authors.forename: A
authors.initials: A
authors.lastname: Albanese
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001767:Blinking / Q000502:physiology*; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010507:Periodicity; D011932:Reading; D012737:Sex Factors; D013060:Speech; D014743:Videotape Recording