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(A) Procedures for the Sleep and S-Deprivation groups for the original first session (left) and for the second session taking place 4 weeks later (right). Red lines
Source publication
Sleep deprivation impairs inhibitory control over reflexive behavior, and this impairment is commonly assumed to dissipate after recovery sleep. Contrary to this belief, here we show that fast reflexive behaviors, when practiced during sleep deprivation, is consolidated across recovery sleep and, thereby, becomes preserved. As a model for the study...
Contexts in source publication
Context 1
... subjects (3 in each group) dropped out and did not participate in this second session. Figure 1A summarizes the design of the main experiment. ...
Context 2
... the main experiments, 2 groups of subjects, a Sleep and an S-Deprivation group, were tested according to procedures illu- strated in Figure 1A. For each test and retest, the subject's propor- tion of express saccades was determined. ...
Context 3
... proportion of express saccades was strongly affected de- pending on whether subjects slept or stayed awake on the night after training (F 1.4, 38.8 = 6.7, P = 0.008, for Group × Test inter- action, Fig. 1B). In the Sleep group, the rate of express saccades re- mained unchanged across the 3 test occasions, that is, across pretest and the retests on Days 1 and 2 (F 2,28 = 0.6, P = 0.55). In con- trast, the subjects of the S-Deprivation group displayed a slight increase in the proportion of express saccades on Day 1 right after the wake ...
Context 4
... S-Deprivation group, rates of express saccades at the pretest of this second session, although on average slightly (but nonsignificantly) lower than at retest on Day 2 of the first experimental session (t (11) = 0.8, P = 0.45), were still significantly enhanced if compared with the initial pretest of the first session (t (11) = −2.6, P = 0.026, Fig. 1C).Nosuch enhancement was seen in the original Sleep group (t (11) = −0.6, P = 0.59, for pretests of the first vs. second experimental session). Moreover, express saccade rates at retest on Day 2 of the initial experimental session predicted the rate of express saccades at the pretest 4 weeks later for both the original S-Deprivation ...
Context 5
... lines) and S-Deprivation groups (gray lines). Sleep-deprived subjects were allowed to sleep already at 18:00 h but usually went to bed later, that is, around 20:00 h, as indicated. saccade rates across pretest and retests reaching significance for the comparison between pretest and retest on Day 2 (P < 0.01, for Wilcoxon's signed rank test, Fig. 1C). A Friedman's test on the 3 testings of each group (P > 0.12) as well as a respective Group × Test ANOVA interaction effect (directly comparing pretest vs. retest on Day 2) failed to reach significance (F 1,22 = 2.4, P = 0.14), which was probably partly due to the reduced sample size at this second ses- sion (n = 24, 6 subjects dropped ...
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Citations
... The main sequence of all visually guided saccades was fitted as in previous studies (44,46) by the common equation: Peak velocity = vmax * (1-e−amplitude/c ) using the fminsearch function within Matlab R . Using the parameters derived from the fit, we calculated saccade peak velocity for a 15 • saccade amplitude. ...
Background
“Central dizziness” due to acute bilateral midline cerebellar disease sparing the posterior vermis has specific oculomotor signs. The oculomotor region of the cerebellar fastigial nucleus (FOR) crucially controls the accuracy of horizontal visually-guided saccades and smooth pursuit eye movements. Bilateral FOR lesions elicit bilateral saccade hypermetria with preserved pursuit. It is unknown whether the initial acceleration of smooth pursuit is impaired in patients with bilateral FOR lesions.
Objective
We studied the effect of a cerebellar lesion affecting the deep cerebellar nuclei on the initial horizontal pursuit acceleration and investigated whether saccade dysmetria also affects other types of volitional saccades, i.e., memory-guided saccades and anti-saccades, which are not performed in immediate response to the visual target.
Methods
We recorded eye movements during a sinusoidal and step-ramp target motion paradigm as well as visually-guided saccades, memory-guided saccades, and anti-saccades in one patient with a circumscribed cerebellar hemorrhage and 18 healthy control subjects using a video-based eye tracker.
Results
The lesion comprised the FOR bilaterally but spared the posterior vermis. The initial pursuit acceleration was low but not significantly different from the healthy control subjects and sinusoidal pursuit was normal. Bilateral saccade hypermetria was not only seen with visually-guided saccades but also with anti-saccades and memory-guided saccades. The final eye position remained accurate.
Conclusion
We provide new insights into the contribution of the bilateral deep cerebellar nuclei on the initial acceleration of human smooth pursuit in midline cerebellar lesions. In line with experimental bilateral FOR lesion data in non-human primates, the initial pursuit acceleration in our patient was not significantly reduced, in contrast to the effects of unilateral experimental FOR lesions. Working memory and neural representation of target locations seem to remain unimpaired. Our data argue against an impaired common command feeding the circuits controlling saccadic and pursuit eye movements and support the hypothesis of independent influences on the neural processes generating both types of eye movements in the deep cerebellar nuclei.
... Although most dominantly observed in monkeys, express saccades in humans have also been observed as a peak in the latency distribution that is separate from ''regular'' saccades (Carpenter, 2001;Fischer & Ramsperger, 1986;Reuter-Lorenz, Hughes, & Fendrich, 1991;Weber, Aiple, Fischer, & Latanov, 1992). Most saccades that we make fall outside the latency range of express saccades, but it is estimated that about 10%-20% of all saccades are express saccades (e.g., Amatya et al., 2011;Knox & Wolohan, 2015;Sprenger et al., 2015). The percentage of express saccades increases when there is a temporal gap between the offset of a fixation point and the onset of a visual target (first described by Saslow, 1967). ...
... Anticipatory saccades are triggered before target information has been processed. It is generally assumed that saccades with latencies below 70 to 80 ms are not based on the processing of external signals, as accuracy for these saccades is usually at chance level if the target location is not known beforehand Sprenger et al., 2015). Therefore, any saccade with a latency shorter than 80 ms was regarded as an anticipatory saccade Wenban-Smith & Findlay, 1991). ...
... So in order to get a grasp of the exact latency at which the distractor starts to have an impact on the saccade endpoint, we separately analyzed the transition from anticipatory to express saccades in the Close Distractor condition. The transition is expected to take place around 80 ms (e.g., Sprenger et al., 2015;Wenban-Smith & Findlay, 1991). As shown by the previous analysis of the whole latency range, this expectation was corroborated by our data from the first three latency bins. ...
It is well known that regular target-driven saccades are affected by the presence of close and remote distractors. Distractors close to the target affect the saccade landing position (known as the global effect), while remote distractors prolong saccade latencies to the target (known as the remote-distractor effect). Little is known about whether a different population of saccades known as express saccades (saccades with very short latencies between 80 and 130 ms) is similarly affected by close and remote distractors, as these saccades are considered to be the result of advanced preparation of an oculomotor program toward the target. We designed a task in which we were able to generate a large number of express saccades, as evidenced by a separate and very early peak in the saccade-latency distribution—a distribution that was different from that of regular saccades. Our results show that irrelevant and unexpected visual input had a large effect on express
saccades. We found a global and a remote-distractor effect which were similar to those seen in regular saccades. Even though our findings confirm the existence of very-short-latency saccades in humans, it is
questionable whether they represent a different population of saccades, as they were equally affected by
the presence of distractors as are regular saccades.
... Vigilance task performance was also not correlated with cue detection in the prospective memory task (all p > 0.05), speaking against the possibility that prospective memory performance was affected by general alertness levels. Alternatively, higher overall performance in wake participants might be interpreted in light of recent findings showing that sleep deprivation can be a state of heightened plasticity due to prefrontal disinhibition (Sprenger et al., 2015). In the wake group, disinhibition under sleep deprivation following the first test session might have triggered plastic changes during subsequent recovery sleep, leading to overall higher performance levels at the second test 2 days later. ...
Sleep has been shown to facilitate the consolidation of prospective memory, which is the ability to execute intended actions at the appropriate time in the future. In a previous study, the sleep benefit for prospective memory was mainly expressed as a preservation of prospective memory performance under divided attention as compared to full attention. Based on evidence that intentions are only remembered as long as they have not been executed yet (cf. ‘Zeigarnik effect’), here we asked whether the enhancement of prospective memory by sleep vanishes if the intention is completed before sleep and whether completed intentions can be reinstated to benefit from sleep again. In Experiment 1, subjects learned cue-associate word pairs in the evening and were prospectively instructed to detect the cue words and to type in the associates in a lexical decision task (serving as ongoing task) 2 h later before a night of sleep or wakefulness. At a second surprise test 2 days later, sleep and wake subjects did not differ in prospective memory performance. Specifically, both sleep and wake groups detected fewer cue words under divided compared to full attention, indicating that sleep does not facilitate the consolidation of completed intentions. Unexpectedly, in Experiment 2, reinstating the intention, by instructing subjects about the second test after completion of the first test, was not sufficient to restore the sleep benefit. However, in Experiment 3, where subjects were instructed about both test sessions immediately after learning, sleep facilitated prospective memory performance at the second test after 2 days, evidenced by comparable cue word detection under divided attention and full attention in sleep participants, whereas wake participants detected fewer cue words under divided relative to full attention. Together, these findings show that for prospective memory to benefit from sleep, (i) the intention has to be active across the sleep period, and (ii) the intention should be induced in temporal proximity to the initial learning session.
... Twenty-seven age-matched healthy subjects [mean age: 70.3±4.7 (SD) years, no significant difference to patients] with no detectable disease affecting postural control served as controls. Oculomotor behavior, i.e. gaze stability, saccades and smooth pursuit eye movements, was recorded in both groups by a video-based eye tracker (EyeLink II, SR Research, ON, CA) and analysed [14,15]. A laser target was used as stimulus (size 0.1˚) which was projected on a screen 140 cm in front of the participants. ...
Background
The cerebellum integrates proprioceptive, vestibular and visual signals for postural control. Cerebellar patients with downbeat nystagmus (DBN) complain of unsteadiness of stance and gait as well as blurred vision and oscillopsia.
Objectives
The aim of this study was to elucidate the differential role of visual input, gaze eccentricity, vestibular and proprioceptive input on the postural stability in a large cohort of cerebellar patients with DBN, in comparison to healthy age-matched control subjects.
Methods
Oculomotor (nystagmus, smooth pursuit eye movements) and postural (postural sway speed) parameters were recorded and related to each other and volumetric changes of the cerebellum (voxel-based morphometry, SPM).
Results
Twenty-seven patients showed larger postural instability in all experimental conditions. Postural sway increased with nystagmus in the eyes closed condition but not with the eyes open. Romberg’s ratio remained stable and was not different from healthy controls. Postural sway did not change with gaze position or graviceptive input. It increased with attenuated proprioceptive input and on tandem stance in both groups but Romberg’s ratio also did not differ. Cerebellar atrophy (vermal lobule VI, VIII) correlated with the severity of impaired smooth pursuit eye movements of DBN patients.
Conclusions
Postural ataxia of cerebellar patients with DBN cannot be explained by impaired visual feedback. Despite oscillopsia visual feedback control on cerebellar postural control seems to be preserved as postural sway was strongest on visual deprivation. The increase in postural ataxia is neither related to modulations of single components characterizing nystagmus nor to deprivation of single sensory (visual, proprioceptive) inputs usually stabilizing stance. Re-weighting of multisensory signals and/or inappropriate cerebellar motor commands might account for this postural ataxia.
... This suggests that sleep recovery of four hours in a day may produce ameliorative effects on the impaired functions of salivary glands produced by sleep deprivation. This finding is consistent with previous studies (Jin et al., 2015;Lungato, Gazarini, Tufik, & D'Almeida, 2015;Rolls et al., 2015;Sprenger et al., 2015) that showed reversal of observations associated with sleep deprivation that resulted from sleep recovery in human and experimental animals. ...
Objective:
Aim of this study was to investigate the effects of sleep deprivation on salivary factors in rats.
Design:
Animals were randomly assigned into three groups of 6 animals each as control, total sleep deprivation (TSD) and partial sleep deprivation (PSD) groups. The multiple platform method was used to induce partial and total sleep deprivation for 7days. On the 8th day, stimulated saliva samples were collected for the analysis of salivary lag time, flow rate, salivary amylase activity, immunoglobulin A secretion rate and corticosterone levels using ELISA and standard kinetic enzyme assay. Data were analyzed using ANOVA with Dunnett T3 post hoc tests.
Results:
Salivary flow rate reduced significantly in the TSD group compared with the PSD group as well as the control group (p=0.01). The secretion rate of salivary IgA was significantly reduced in the TSD group compared with the control group (p=0.04). Salivary amylase activity was significantly elevated in the TSD group compared with the PSD group as well as control group (p<0.001). However, there were no significant changes in the salivary lag time and levels of corticosterone among the groups.
Conclusions:
These findings suggest that total sleep deprivation is associated with reduced salivary flow rate and secretion rate of IgA as well as elevated levels of salivary amylase activity in rats. However, sleep recovery of four hours in the PSD group produced ameliorative effects on the impaired functions of salivary glands.
... Although most dominantly observed in monkeys, express saccades in humans have also been observed as a peak in the latency distribution that is separate from ''regular'' saccades (Carpenter, 2001;Fischer & Ramsperger, 1986;Reuter-Lorenz, Hughes, & Fendrich, 1991;Weber, Aiple, Fischer, & Latanov, 1992). Most saccades that we make fall outside the latency range of express saccades, but it is estimated that about 10%-20% of all saccades are express saccades (e.g., Amatya et al., 2011;Knox & Wolohan, 2015;Sprenger et al., 2015). The percentage of express saccades increases when there is a temporal gap between the offset of a fixation point and the onset of a visual target (first described by Saslow, 1967). ...
... Anticipatory saccades are triggered before target information has been processed. It is generally assumed that saccades with latencies below 70 to 80 ms are not based on the processing of external signals, as accuracy for these saccades is usually at chance level if the target location is not known beforehand Sprenger et al., 2015). Therefore, any saccade with a latency shorter than 80 ms was regarded as an anticipatory saccade Wenban-Smith & Findlay, 1991). ...
... So in order to get a grasp of the exact latency at which the distractor starts to have an impact on the saccade endpoint, we separately analyzed the transition from anticipatory to express saccades in the Close Distractor condition. The transition is expected to take place around 80 ms (e.g., Sprenger et al., 2015;Wenban-Smith & Findlay, 1991). As shown by the previous analysis of the whole latency range, this expectation was corroborated by our data from the first three latency bins. ...
It is well known that under specific conditions, saccades can be made with extremely short latencies (about 110 to 130 ms). These so-called Express Saccades (ES) have been observed in animals showing two separate peaks in the saccade latencies distributions. Up till now, separate peaks in the distribution have not been observed in human observers. In two experiments we investigated the saccade latency distribution while examining two well-known target-distractor interactions. We examined the Global Effect (GE) which occurs when a distractor is presented in close proximity of the target. Typically, saccades tend to land at a location between target and distractor. In addition we examined the Remote Distractor Effect (RDE), an effect which describes the longer saccade latencies when a distractor is presented further away from a target. In both experiments participants made saccades to a sudden onset target. In some trials the target was accompanied by a distractor close or remote from the target. A gap-paradigm ensured a high percentage of low latency saccades. In Experiment 1, participants were given a 100% valid cue and a warning tone to indicate the impending target and its location and qualitative feedback on the response time. In Experiment 2 the timing was identical but we presented no cue, no warning toine and neutral feedback was provided. The paradigm triggered high percentages of ES. Extraordinarily, the latency distribution in Experiment 1 showed two distinct, separate peaks. This suggests that, as has been suggested based on animal studies, a separate process that results in ES is involved in the processing of early visual information in human observers. In addition, results show a GE and a RDE, even for the fastest visually triggered saccades. This indicates that endogenously prepared ES are not immune to exogenous influences and are moderated by early visual input.
Meeting abstract presented at VSS 2016
