Mathematical procedures in data recording and processing of pupillary fatigue waves

Lüdtke, Holger; Wilhelm, Barbara; Adler, Martin W.; Schaeffel, Frank; Wilhelm, Helmut

doi:10.1016/s0042-6989(98)00081-9

Cited by 182 publications

(153 citation statements)

References 5 publications

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“…247.5 s -660 s) was measured to compute the mean test PUI score (see [12] for precedent where baseline was the first minute and test PUI was minutes 4-11). Peak PUI is both achieved and maintained from approximately minute 4 of the pupillography test [12,22].…”

Section: Physiological Measuresmentioning

confidence: 86%

The effect of chewing gum on physiological and self-rated measures of alertness and daytime sleepiness

Johnson

Miles

Haddrell

et al. 2012

Physiology & Behavior

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AcknowledgmentsThe authors would like to thank two anonymous reviewers for their comments on an earlier draft of the manuscript. AbstractThe proposition that chewing gum can improve alertness was investigated via both physiological and self-rated measures. The Pupillographic Sleepiness Test (PST) provided a measure of pupillary unrest (PUI); a physiological index of daytime sleepiness. Chewing gum reduced the extent of sleepiness as measured by both PUI and self-rated sleepiness. Specifically, in comparison with sham chewing and no chewing controls, the chewing gum condition significantly limited the increase in pupillary unrest following the 11-minute PST within a darkened laboratory: a finding indicating moderation of the daytime sleepiness increase for the chewing gum condition. In addition, there was some evidence that chewing gum (relative to the nochewing condition only) moderated the increase in a self-rated measure of sleepiness (Stanford Sleepiness Scale). However, there was no evidence that chewing gum moderated the decrease in self-rated alertness (Bond-Lader Visual Analogue Mood Scale). Although the precise mechanism underpinning the effect of chewing gum is unclear, the reduction in daytime sleepiness may be underpinned via heightened cerebral activity following the chewing of gum or the arousing effects of mint flavour.

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Section: Physiological Measuresmentioning

confidence: 86%

The effect of chewing gum on physiological and self-rated measures of alertness and daytime sleepiness

Johnson

Miles

Haddrell

et al. 2012

Physiology & Behavior

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“…These pupil fluctuations are regarded as a physiological index of alertness level (Lowenstein et al, 1963;Yoss et al, 1970;Lüdtke et al, 1998). The PST quantitatively analyzes these pupil fluctuations and yields two measurements: pupillary unrest index (PUI: the distance traveled by the margin of the pupil over a 1-min period) and the total power of the pupil diameter fluctuations (obtained from a fast Fourier transform).…”

Section: Tests and Apparatusmentioning

confidence: 99%

Modulation of the Acoustic Startle Response by the Level of Arousal: Comparison of Clonidine and Modafinil in Healthy Volunteers

Samuels

Hou

Langley

et al. 2007

Neuropsychopharmacol

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A sudden loud sound evokes an electromyographic (EMG) response from the orbicularis oculi muscle in humans together with an auditory evoked potential (AEP) and an increase in skin conductance (SC). Startle responses are inhibited by weak prepulses (prepulse inhibition, (PPI)) and may also be modified by the level of alertness. We compared the sedative drug clonidine and the alerting drug modafinil on sound-evoked EMG, AEP, and SC responses, on the PPI of these responses and on level of arousal and autonomic functions. Sixteen healthy male volunteers participated in four weekly sessions (clonidine 0.2 mg, modafinil 400 mg, their combination, placebo) in a double-blind, cross-over, balanced design. Responses were evoked by sound pulses of 115 and 85 dB (PPI) for 40 ms and recorded conventionally. Level of alertness, autonomic functions (pupil diameter, blood pressure, heart rate, salivation, temperature) and the plasma levels of the hormones prolactin, thyroid-stimulating hormone and growth hormone were also measured. Data were analyzed with analysis of variance with multiple comparisons. Both prepulses and clonidine attenuated all three startle responses and modafinil antagonized clonidine's effects on the EMG and AEP responses. None of the drugs affected PPI. Clonidine showed sedative and sympatholytic effects, and modafinil showed alerting and sympathomimetic effects. In conclusion, startle responses were susceptible not only to PPI but also to the level of arousal. Keywords: acoustic startle response; auditory evoked potential; skin conductance; prepulse inhibition; clonidine; modafinil INTRODUCTIONThe startle response involves rapid involuntary contractions of facial and skeletal musculature in response to a sudden intense stimulus. In the case of the acoustic startle response, this reaction occurs in response to a sudden loud sound and is measurable in humans as an electromyographic (EMG) response from the orbicularis oculi muscle (eyeblink startle response). This response is believed to be mediated via a pathway below the level of the diencephalon consisting of between three and five central synapses, originating from the sensory receptors and terminating on the motor neurons, where the principal relay is the caudal pontine reticular nucleus (Davis et al, 1982; for review, see Yeomans and Frankland, 1996;Koch, 1999). In addition to this muscular response, changes in electroencephalographic (EEG) activity can be observed in response to the auditory stimulus, and these changes are termed auditory evoked potentials (AEP). In particular, the N1/P2 component of the AEP is measurable following the presentation of the acoustic startle stimulus (for examples, see Abduljawad et al, 1999Abduljawad et al, , 2001 Phillips et al, 2000a, b;Graham et al, 2001Graham et al, , 2004Scaife et al, 2005Scaife et al, , 2006. Both the muscular and the AEP responses are fast responses; longer-latency responding to the startle stimulus can be observed in autonomic activity, in particular in sympathetically mediated skin conductance...

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“…The PUI corresponds to the sum of the absolute differences in pupil diameter averaged across 16 consecutive data points. This sum was then normalized over a 1 min period (for more details, see Schaeffel et al, 1993;Lüdtke et al, 1998).…”

Section: Sedation Evaluationmentioning

confidence: 99%

Lorazepam Strongly Prolongs Visual Information Processing

Giersch

Herzog

2004

Neuropsychopharmacol

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Lorazepam is a drug that has been widely used for over 30 years. Whereas its therapeutic and amnestic effects are fairly well known, the visuo-perceptual impairments induced by this drug have been studied to a much lesser degree and only little is known about the influence of lorazepam on the time course of visual information processing. To gain a better insight specifically on these temporal characteristics, we used the recently discovered backward masking technique, 'shine-through', in which a vernier target precedes a grating. We tested subjects, treated with lorazepam, diazepam, or a placebo, with masking gratings of various spatial layouts. Our experiments reveal surprising results. First, for the unmasked vernier target, lorazepam induced a strong deterioration of performance compared to both diazepam and placebo. Performance deteriorated even more significantly if a masking grating was presented following the vernier. We observed that vernier discrimination could be completely abolished even if the grating appeared 400 ms after the vernier presentation. Such long time intervals are beyond usual visual masking effects. When performing the task under placebo, the participants perceived the vernier target and the masking grating as two independent time events rather than as a single event. It appears that lorazepam prolongs dramatically the processing of visual targets. The masking effects revealed here are specific to the type of grating and are much stronger under lorazepam than under diazepam.

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Mathematical procedures in data recording and processing of pupillary fatigue waves

Cited by 182 publications

References 5 publications

The effect of chewing gum on physiological and self-rated measures of alertness and daytime sleepiness

The effect of chewing gum on physiological and self-rated measures of alertness and daytime sleepiness

Modulation of the Acoustic Startle Response by the Level of Arousal: Comparison of Clonidine and Modafinil in Healthy Volunteers

Lorazepam Strongly Prolongs Visual Information Processing

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