Table 1.

Suggested research topics related to yawn duration, cognition and neural processing.

• Investigate whether yawn duration predicts similar neurological parameters in other vertebrates
• Examine how variation in more specific neuroanatomical structures predicts yawn duration across different species
• Explore whether differences in yawn duration predict variability in brain size and neuroanatomy within a species
• Investigate whether within-species variability in yawn duration correlates with measures of cognitive ability
• Determine whether within-subject yawn duration varies as a function of cognitive load or cortical arousal
• Explore whether within-subject variability in yawn duration follows a circadian pattern
• Examine whether variation in yawn duration correlates with changes in neural activity (EEG) in humans
• Explore whether yawn duration differs within human populations with reduced brain/cognitive functioning
• Determine whether spontaneous and contagious yawns vary in duration or magnitude
• Investigate how yawn duration varies across the lifespan*
  • *Note: Analyses in the electronic supplementary material begin to address this question.