Context-Specific Gain Switching in the Human Vestibuloocular Reflex

The role of the otoliths in mammals in the angular vestibuloocular reflex (VOR) has been difficult to determine because there is no surgical technique that can reliably ablate them without damaging the semicircular canals. The Otopetrin1 (Otop1) mouse lacks functioning otoliths because of failure to develop otoconia but seems to have otherwise normal peripheral anatomy and neural circuitry. By using these animals we sought to determine the role of the otoliths in angular VOR baseline function and adaptation. In six Otop1 mice and six control littermates we measured baseline ocular countertilt about the three primary axes in head coordinates; baseline horizontal (rotation about an Earth-vertical axis parallel to the dorsal-ventral axis) and vertical (rotation about an Earth-vertical axis parallel to the interaural axis) sinusoidal (0.2–10 Hz, 20–100°/s) VOR gain (= eye/head velocity); and the horizontal and vertical VOR after gain-increase (1.5×) and gain-decrease (0.5×) adaptation training. Countertilt responses were significantly reduced in Otop1 mice. Baseline horizontal and vertical VOR gains were similar between mouse types, and so was horizontal VOR adaptation. For control mice, vertical VOR adaptation was evident when the testing context, left ear down (LED) or right ear down (RED), was the same as the training context (LED or RED). For Otop1 mice, VOR adaptation was evident regardless of context. Our results suggest that the otolith translational signal does not contribute to the baseline angular VOR, probably because the mouse VOR is highly compensatory, and does not alter the magnitude of adaptation. However, we show that the otoliths are important for gravity context-specific angular VOR adaptation. NEW & NOTEWORTHY This is the first study examining the role of the otoliths (defined here as the utricle and saccule) in adaptation of the angular vestibuloocular reflex (VOR) in an animal model in which the otoliths are reliably inactivated and the semicircular canals preserved. We show that they do not contribute to adaptation of the normal angular VOR. However, the otoliths provide the main cue for gravity context-specific VOR adaptation.

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Context-Specific Adaptation of the Vertical Vestibuloocular Reflex With Regard to Gravity

Journal of Neurophysiology ◽

10.1152/jn.2000.84.6.3067 ◽

2000 ◽

Vol 84 (6) ◽

pp. 3067-3071 ◽

Cited By ~ 34

Author(s):

Sergei B. Yakushin ◽

Theodore Raphan ◽

Bernard Cohen

Keyword(s):

Head Movement ◽

Contralateral Side ◽

Head Position ◽

Head Orientation ◽

Vestibuloocular Reflex ◽

Ipsilateral Side ◽

Specific Adaptation ◽

Specific Effects ◽

Gain Adaptation ◽

Context Specific

We determined whether head position with regard to gravity is an important context for angular vestibuloocular reflex (aVOR) gain adaptation. Vertical aVOR gains were adapted with monkeys upright or on side by rotating the animals about an interaural axis in phase or out of phase with the visual surround for 4 h. When aVOR gains were adapted with monkeys upright, gain changes were symmetrical when tested in either on-side position (23 ± 7%; mean ± SD). After on-side adaptation, however, gain changes were always larger when animals were tested in the same on-side position in which they were adapted. Gain changes were 43 ± 16% with ipsilateral side down and 9 ± 8% with contralateral side down. The context-specific effects of head position on vertical aVOR gain were the same whether the gain was increased or decreased. The data indicate that vertical aVOR gain changes are stored in the context of the head orientation in which changes were induced. This association could be an important context for expressing the adapted state of the aVOR gain during vertical head movement.

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Angular vestibuloocular reflex responses in Otop1 mice. II. Otolith sensor input improves compensation after unilateral labyrinthectomy

Journal of Neurophysiology ◽

10.1152/jn.00812.2018 ◽

2019 ◽

Vol 121 (6) ◽

pp. 2300-2307 ◽

Cited By ~ 4

Author(s):

Serajul I. Khan ◽

Charles C. Della Santina ◽

Americo A. Migliaccio

Keyword(s):

Semicircular Canals ◽

Vertical Axis ◽

Vestibuloocular Reflex ◽

Peripheral Injury ◽

Axis Parallel ◽

Vor Adaptation ◽

Unilateral Labyrinthectomy ◽

Context Specific ◽

Gain Loss

The role of the otoliths in mammals in the normal angular vestibuloocular reflex (VOR) was characterized in an accompanying study based on the Otopetrin1 (Otop1) mouse, which lacks functioning otoliths because of failure to develop otoconia but seems to have otherwise normal peripheral anatomy and neural circuitry. That study showed that otoliths do not contribute to the normal horizontal (rotation about Earth-vertical axis parallel to dorso-ventral axis) and vertical (rotation about Earth-vertical axis parallel to interaural axis) angular VOR but do affect gravity context-specific VOR adaptation. By using these animals, we sought to determine whether the otoliths play a role in the angular VOR after unilateral labyrinthectomy when the total canal signal is reduced. In five Otop1 mice and five control littermates we measured horizontal and vertical left-ear-down and right-ear-down sinusoidal VOR (0.2–10 Hz, 20–100°/s) during the early (3–5 days) and plateau (28–32 days) phases of compensation after unilateral labyrinthectomy and compared these measurements with baseline preoperative responses from the accompanying study. From similar baselines, acute gain loss was ~25% less in control mice, and chronic gain recovery was ~40% more in control mice. The acute data suggest that the otoliths contribute to the angular VOR when there is a loss of canal function. The chronic data suggest that a unilateral otolith signal can significantly improve angular VOR compensation. These data have implications for vestibular rehabilitation of patients with both canal and otolith loss and the development of vestibular implants, which currently only mimic the canals on one side.NEW & NOTEWORTHY This is the first study examining the role of the otoliths (defined here as the utricle and saccule) on the acute and chronic angular vestibuloocular reflex (VOR) after unilateral labyrinthectomy in an animal model in which the otoliths are reliably inactivated and the semicircular canals preserved. This study shows that the otolith signal is used to augment the acute angular VOR and help boost VOR compensation after peripheral injury.

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Validation of the Procrastination at Work Scale

European Journal of Psychological Assessment ◽

10.1027/1015-5759/a000554 ◽

2020 ◽

Vol 36 (5) ◽

pp. 767-776

Author(s):

U. Baran Metin ◽

Toon W. Taris ◽

Maria C. W. Peeters ◽

Max Korpinen ◽

Urška Smrke ◽

...

Keyword(s):

Work Engagement ◽

Discriminant Validity ◽

Psychometric Characteristics ◽

The Czech Republic ◽

The United Kingdom ◽

Confirmatory Factor ◽

And Performance ◽

Context Specific ◽

Negative Links ◽

Office Employees

Abstract. Procrastination at work has been examined relatively scarcely, partly due to the lack of a globally validated and context-specific workplace procrastination scale. This study investigates the psychometric characteristics of the Procrastination at Work Scale (PAWS) among 1,028 office employees from seven countries, namely, Croatia, the Czech Republic, Finland, Slovenia, Turkey, Ukraine, and the United Kingdom. Specifically, it was aimed to test the measurement invariance of the PAWS and explore its discriminant validity by examining its relationships with work engagement and performance. Multi-group confirmatory factor analysis shows that the basic factor structure and item loadings of the PAWS are invariant across countries. Furthermore, the two subdimensions of procrastination at work exhibited different patterns of relationships with work engagement and performance. Whereas soldiering was negatively related to work engagement and task performance, cyberslacking was unrelated to engagement and performance. These results indicate further validity evidence for the PAWS and the psychometric characteristics show invariance across various countries/languages. Moreover, workplace procrastination, especially soldiering, is a problematic behavior that shows negative links with work engagement and performance.

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Ambulatory Assessment

European Psychologist ◽

10.1027/1016-9040.14.2.109 ◽

2009 ◽

Vol 14 (2) ◽

pp. 109-119 ◽

Cited By ~ 66

Author(s):

Ulrich W. Ebner-Priemer ◽

Timothy J. Trull

Keyword(s):

Real Time ◽

Clinical Psychology ◽

Real Life ◽

Ambulatory Assessment ◽

Computer Assisted ◽

Affective Valence ◽

Time Data ◽

Physiological Processes ◽

Context Specific ◽

Questionnaire Studies

Convergent experimental data, autobiographical studies, and investigations on daily life have all demonstrated that gathering information retrospectively is a highly dubious methodology. Retrospection is subject to multiple systematic distortions (i.e., affective valence effect, mood congruent memory effect, duration neglect; peak end rule) as it is based on (often biased) storage and recollection of memories of the original experience or the behavior that are of interest. The method of choice to circumvent these biases is the use of electronic diaries to collect self-reported symptoms, behaviors, or physiological processes in real time. Different terms have been used for this kind of methodology: ambulatory assessment, ecological momentary assessment, experience sampling method, and real-time data capture. Even though the terms differ, they have in common the use of computer-assisted methodology to assess self-reported symptoms, behaviors, or physiological processes, while the participant undergoes normal daily activities. In this review we discuss the main features and advantages of ambulatory assessment regarding clinical psychology and psychiatry: (a) the use of realtime assessment to circumvent biased recollection, (b) assessment in real life to enhance generalizability, (c) repeated assessment to investigate within person processes, (d) multimodal assessment, including psychological, physiological and behavioral data, (e) the opportunity to assess and investigate context-specific relationships, and (f) the possibility of giving feedback in real time. Using prototypic examples from the literature of clinical psychology and psychiatry, we demonstrate that ambulatory assessment can answer specific research questions better than laboratory or questionnaire studies.

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