Some methodological issues in the assessment of the spontaneous eyeblink frequency in man

Previous assessments of spontaneous eyeblink frequency (SEBF) or interblink intervals (IBI) have been made over period of 0.5 to 15min and average values calculated; the reliability of the methods has not been validated. Video recordings were made of 14 healthy volunteers, aged 20 to 38 years, while silently fixating on a 2 m distant, 35 mm high target under 350 lux illumination and the traces assessed with an event marker. Significant fluctuations in SEBF or IBI were generally observed, but which did not conform to a minute‐by‐minute periodicity. Time‐dependent trends were uncommon, although uncritical pooling or averaging of data can effectively conceal such fluctuations or trends. Correlation's between SEBF and IBI indicate that eye‐blink monitoring over at least 3 min is required. Simple averaging calculations are not appropriate because of a high chance of non‐Gaussian distribution of data. Modal IBI values correlated well with an adjusted modal calculated SEBF which is thus recommended for further use.

[1]  E. Ponder,et al.  ON THE ACT OF BLINKING , 1927 .

[2]  K. M. Michels,et al.  Muscular tension and the human blink rate. , 1957, Journal of experimental psychology.

[3]  L. DeLisi,et al.  An Inverse Correlation between Spontaneous Eye-Blink Rate and Platelet Monoamine Oxidase Activity , 1983, British Journal of Psychiatry.

[4]  J H Mackintosh,et al.  Blink Rate in Psychiatric Illness , 1983, British Journal of Psychiatry.

[5]  C. Kaufmann,et al.  Eye‐Blink Rate in Tourette's Syndrome , 1985, The Journal of nervous and mental disease.

[6]  A. Hall.  THE ORIGIN AND PURPOSES OF BLINKING*† , 1945, The British journal of ophthalmology.

[7]  S. Lovestone.  Periodic Psychosis Associated with the Menstrual Cycle and Increased Blink Rate , 1992, British Journal of Psychiatry.

[8]  M. Yap.  Tear break‐up time is related to blink frequency , 1991, Acta ophthalmologica.

[9]  J. Kleinman,et al.  Eye-blinking and cerebral ventricular size in chronic schizophrenic patients. , 1984, The American journal of psychiatry.

[10]  C. Karson.  Spontaneous eye-blink rates and dopaminergic systems. , 1983, Brain : a journal of neurology.

[11]  L. Carney,et al.  THE NATURE OF NORMAL BLINKING PATTERNS , 1982, Acta ophthalmologica.

[12]  J. Prause,et al.  Relation between blink frequency and break‐up time? , 1987, Acta ophthalmologica.

[13]  R. Nelson,et al.  Reaction times for hand movements made in response to visual versus vibratory cues. , 1990, Somatosensory & motor research.

[14]  J. D. Rains.  SIGNAL LUMINANCE AND POSITION EFFECTS IN HUMAN REACTION TIME. , 1963, Vision research.

[15]  R S Baker,et al.  Age-related changes in human blinks. Passive and active changes in eyelid kinematics. , 1997, Investigative ophthalmology & visual science.

[16]  Karson Cn.  Physiology of normal and abnormal blinking. , 1988 .

[17]  M. Collins,et al.  Blinking Patterns in Soft Contact Lens Wearers Can Be Altered with Training , 1987, American journal of optometry and physiological optics.

[18]  P. Solomon,et al.  Disruption of human eyeblink conditioning after central cholinergic blockade with scopolamine. , 1993, Behavioral neuroscience.

[19]  M. Abelson,et al.  A tentative mechanism for inferior punctate keratopathy. , 1977, American journal of ophthalmology.

[20]  C. Karson,et al.  Physiology of normal and abnormal blinking. , 1988, Advances in neurology.

[21]  J. Stern,et al.  The endogenous eyeblink. , 1984, Psychophysiology.

[22]  H. Merckelbach,et al.  Eyeblink frequency, rehearsal activity, and sympathetic arousal. , 1990, The International journal of neuroscience.