Does the chronotype classification need to be updated? Preliminary findings.
Traditionally, chronotype classification is based on the Morningness-Eveningness Questionnaire (MEQ). It is implicit in the classification that intermediate individuals get intermediate scores to most of the MEQ questions. However, a small group of individuals has a different pattern of answers. In some questions, they answer as "morning-types" and in some others they answer as "evening-types," resulting in an intermediate total score. "Evening-type" and "Morning-type" answers were set as A(1) and A(4), respectively. Intermediate answers were set as A(2) and A(3). The following algorithm was applied: Bimodality Index = (Sigma A(1) x Sigma A(4))(2) - (Sigma A(2) x Sigma A(3))(2). Neither-types that had positive bimodality scores were classified as bimodal. If our hypothesis is validated by objective data, an update of chronotype classification will be required.
Martynhak
Bruno Jacson
BJ
Department of Pharmacology, Federal University of Paraná, Curitiba, Brazil. brunojm@ymail.com
Louzada
Fernando Mazzilli
FM
Pedrazzoli
Mário
M
Araujo
John Fontenele
JF
D000293:Adolescent; D000465:Algorithms; D000818:Animals; D001938:Brazil; D002940:Circadian Rhythm; D005260:Female; D006801:Humans; D008297:Male; D008954:Models, Biological; D015233:Models, Statistical; D017440:Photoperiod; D011795:Surveys and Questionnaires; D055815:Young Adult