Papers by Ari Z Zivotofsky
Science News, Jan 23, 1999
Investigative Ophthalmology & Visual Science, Jun 10, 2020
Investigative Ophthalmology & Visual Science, Jul 13, 2018
Judaism, Jun 22, 1994
Pourquoi Dieu choisit Moise pour conduire son peuple ? La presente etude repond a cette interroga... more Pourquoi Dieu choisit Moise pour conduire son peuple ? La presente etude repond a cette interrogation en examinant les recits rabbiniques mais surtout bibliques qui font intervenir Moise avant qu'il ne devienne le guide du peuple hebreu. Moise fut choisi par Dieu avant tout pour la lutte qu'il mena contre l'injustice
Investigative Ophthalmology & Visual Science, Jun 16, 2013
Aktuelle Neurologie, Sep 1, 2008
Neuroscience Letters, Mar 1, 2005
The visual system serves two distinct functions. The information acquired by it is used to both c... more The visual system serves two distinct functions. The information acquired by it is used to both create a percept of the external world and to guide motor actions. In recent years there has been considerable debate regarding whether the same information is utilized and processed in the same manner in the two tasks. The Duncker Illusion, also known as induced motion, is an illusion of motion that results when there is background movement, and it neatly dissociates true from perceived motion. We examined the open-loop period of smooth eye tracking of a target that had an illusory component to its trajectory due to background motion. It was found that the eyes moved in the direction of background motion and of true target motion but not in the illusory direction, despite the strong percept of illusory motion experienced by all subjects. This finding lends support to the hypothesis of separate neurological pathways for the processing of visual information used to create the conscious percept and visual information used to drive motor actions.
Journal of the Neurological Sciences
Human Factors, May 29, 2012
Investigative Ophthalmology & Visual Science, Jul 22, 2019
Experimental Brain Research, Feb 8, 2018
When a person suddenly looks in a certain direction, others seem to shift their attention to the ... more When a person suddenly looks in a certain direction, others seem to shift their attention to the same, looked-at, location. This common observation, that gaze-of-another seems to trigger reflexive shifts of attention within an observer, has been demonstrated in various studies. Yet just how reflexive it truly is, is an ongoing controversy. Unlike most studies in which gaze cues were distractors in a cueing paradigm, the current study used gaze cues as triggers in a mixed pro-and anti-saccade task and a Posner-like discrimination task. In a set of two experiments, we investigated whether attention triggered by gazeof-another differs from attention triggered by peripheral (exogenous) and arrow stimuli. In the first experiment, gaze cues resulted in slowed saccadic responses and in the elimination of the anti-saccade-cost associated with reflexive orienting. Prosaccades triggered by peripheral cues had significantly fewer errors and shorter reaction times than anti-saccades. However, there was no significant difference between pro and anti-saccades triggered by gaze cues. Thus, counter to expectations, gaze did not produce reflexive shifts of overt attention. The second experiment showed that attention triggered by gaze cues is no different from attention triggered by biologically irrelevant arrow cues. They both eliminated the anti-saccade-cost and displayed prolonged reaction times. However, manual discrimination RTs showed no significant differences between gaze and peripheral cues. Together, these results suggest that neither gaze nor arrow cues trigger reflexive shifts of overt attention.
Behavioral Neuroscience, Aug 1, 2006
Food deprivation has been shown to deleteriously affect human cognition, but findings are equivoc... more Food deprivation has been shown to deleteriously affect human cognition, but findings are equivocal, and few studies have examined several cognitive domains. In this study, the authors used computerized testing to describe the profile of shifts in cognition attributable to short-term religious fasting. Multiple cognitive domains were evaluated at midday and late afternoon following complete abstention from eating and drinking beginning at midnight. Cross-domain, fasting-related deficits were found for tasks requiring perception of spatial relations. Fasting-related information processing deficits were found for response time but not accuracy for test levels of intermediate difficulty. Time-of-day effects often reflected poorer afternoon performance. These findings provide a detailed profile of cognitive consequences of food deprivation, affected by time of day, task demands, and type of outcome.
Investigative Ophthalmology & Visual Science, Sep 26, 2016
PLOS ONE, Feb 21, 2017
The pro and anti-saccade task (PAT) is a widely used tool in the study of overt and covert attent... more The pro and anti-saccade task (PAT) is a widely used tool in the study of overt and covert attention with promising potential role in neurocognitive and psychiatric assessment. However, specific PAT protocols can vary significantly between labs, potentially resulting in large variations in findings across studies. In light of recent calls towards a standardization of PAT the current study's objective was to systematically and purposely evaluate the effects of block vs. interleaved administration-a fundamental consideration-on PAT measures in a within subject design. Additionally, this study evaluated whether measures of a Posner-type cueing paradigm parallels measures of the PAT paradigm. As hypothesized, results indicate that PAT performance is highly susceptible to administration mode. Interleaved mode resulted in larger error rates not only for anti (blocks: M = 22%; interleaved: M = 42%) but also for pro-saccades (blocks: M = 5%; interleaved: M = 12%). This difference between block and interleaved administration was significantly larger in anti-saccades compared to pro-saccades and cannot be attributed to a 'speed/accuracy tradeoff'. Interleaved mode produced larger pro and anti-saccade differences in error rates while block administration produced larger latency differences. Results question the reflexive nature of pro-saccades, suggesting they are not purely reflexive. These results were further discussed and compared to previous studies that included within subject data of blocks and interleaved trials.
Copeia, May 1, 2004
ABSTRACT
Meat Science, Apr 1, 2012
This article appeared in a journal published by Elsevier. The attached copy is furnished to the a... more This article appeared in a journal published by Elsevier. The attached copy is furnished to the author for internal non-commercial research and education use, including for instruction at the authors institution and sharing with colleagues. Other uses, including reproduction and distribution, or selling or licensing copies, or posting to personal, institutional or third party websites are prohibited. In most cases authors are permitted to post their version of the article (e.g. in Word or Tex form) to their personal website or institutional repository. Authors requiring further information regarding Elsevier's archiving and manuscript policies are
Vision Research, Dec 1, 1997
We measured the eye movements of three sisters with Niemann-Pick type C disease who had a selecti... more We measured the eye movements of three sisters with Niemann-Pick type C disease who had a selective defect of vertical saccades, which were slow and hypometric. Horizontal saccades, and horizontal and vertical pursuit and vestibular eye movements were similar to control subjects. The initial movement of oblique saccades was mainly horizontal and most of the vertical component occurred after the horizontal component ended; this resulted in strongly curved trajectories. After completion of the horizontal component of an oblique saccade, the eyes oscillated horizontally at 10-20 Hz until the vertical component ended. These findings are best explained by models that incorporate separate feedback loops for horizontal and vertical burst neurons, and in which the disease selectively affects vertical burst neurons. Published by Elsevier Science Ltd Niemann-Pick Eye movements Saccades Brainstem
Journal of Neurophysiology, Jun 1, 1998
There is evidence for a linkage Using the magnetic search coil technique to record eye and lid be... more There is evidence for a linkage Using the magnetic search coil technique to record eye and lid between the circuitry producing saccades and the neural cirmovements, we investigated the effect of voluntary blinks on horicuits subserving blinks (Evinger et al. 1994). The concurzontal saccades in five normal human subjects. The main goal of rence of a blink and its size depends not only on the size of the study was to determine whether changes in the dynamics of the saccade but also on visual requirements (Beideman and saccades with blinks could be accounted for by a superposition of Stern 1977; Fogarty and Stern 1989). Both saccades and the eye movements induced by blinks as subjects fixated a stationary target and saccadic movements made without a blink. First, blinks interfere with vision, and are time locked. subjects made voluntary blinks as they fixed on stationary targets
Vision Research, Jul 1, 1996
We compared horizontal and vertical smooth pursuit eye movements in five healthy human subjects. ... more We compared horizontal and vertical smooth pursuit eye movements in five healthy human subjects. When maintenance of pursuit was tested using predictable waveforms (sinusoidal or triangular target motion), the gain of horizontal pursuit was greater, in all subjects, than that of vertical pursuit; this was also the case for the horizontal and vertical components of diagonal and circular tracking. When initiation of pursuit was tested, four subjects tended to show larger eye accelerations for vertical as opposed to horizontal pursuit; this trend became a consistent tinding during diagonal tracking. These findings support the view that different mechanisms govern the onset of smooth pursuit, and its subsequent maintenance when the target moves in a predictable waveform. Since the properties of these two aspects of pursuit differ for horizontal and vertical movements, our findings also point to separate control of horizontal and vertical pursuit. Copyright @ 1996 Elsevier Science Ltd. Smooth pursuit Eye movements Step-ramps Human
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Papers by Ari Z Zivotofsky