Abstract：
:A variable pupil generally regulates the amount of incoming light available for image formation on the retina. However, some of the semi-aquatic snakes (North American Gartersnakes, Thamnophis) that forage in relatively low light conditions reduce the pupil aperture in response to submergence underwater at the expense incoming light. Given that these snakes have all-cone retinas, reduction of incoming light because of pupillary constriction upon immersion seems counterintuitive. To test the effect of light and water on pupil aperture, three species of North American Gartersnakes (T. atratus, T. hammondii, and T. sirtalis) were exposed to nine light intensities in air and water. There was no effect of light on relative pupil aperture for any species. However, all three species showed a significant reduction in pupil aperture upon submergence underwater. The lack of a light response is surprising, and may be related to the method of accommodation in snakes. Snakes lack a ciliary muscle, and move the lens by constricting the pupil, which increases pressure in the posterior chamber and pushes the lens forward. Upon submergence, the snakes may be attempting to overcome the change in refractive index and defocus imposed by the water, by constricting the pupil. Thus, having the iris muscle involved in accommodation may preclude it from much of a light regulating function.
journal_name
Vision Resjournal_title
Vision researchauthors
Fontenot CL Jrdoi
10.1016/j.visres.2008.01.006subject
Has Abstractpub_date
2008-07-01 00:00:00pages
1663-9issue
15eissn
0042-6989issn
1878-5646pii
S0042-6989(08)00025-4journal_volume
48pub_type
杂志文章相关文献
VISION RESEARCH文献大全abstract：:We compared the thresholds and response properties of extracellularly recorded retinal ganglion cells (RGCs) in wild-type and rd1 mouse retinas to electrical stimulation of the retinal neural network. Retinas were stimulated in vitro with biphasic current pulses (1 ms/phase) applied with a 400-microm diameter, subreti...
journal_title：Vision research
pub_type： 杂志文章
doi：10.1016/j.visres.2008.04.016
更新日期：2008-06-01 00:00:00
abstract：:A dichoptic display in which the images are cyclorotated in opposite directions does not appear inclined. This suggests that perceived inclination depends on the difference between horizontal-shear and vertical-shear disparity. Large random-dot stereoscopic displays were presented with various types of shear disparity...
journal_title：Vision research
pub_type： 杂志文章
doi：10.1016/0042-6989(94)90237-2
更新日期：1994-10-01 00:00:00
abstract：:The ability to identify faces is of critical importance for normal social interactions. Previous evidence suggests that early visual deprivation may impair certain aspects of face recognition. The effects of strabismic amblyopia on face processing have not been investigated previously. In this study, a group of indivi...
journal_title：Vision research
pub_type： 杂志文章
doi：10.1016/j.visres.2013.01.007
更新日期：2013-03-22 00:00:00
abstract：:The gaze of another modulates and shifts an observer's spatial attention toward this gaze direction. This phenomenon is termed joint attention. Although previous studies found joint attention was induced during a spatial working memory task, it remains an open question whether spatial working memory interferes with jo...
journal_title：Vision research
pub_type： 杂志文章
doi：10.1016/j.visres.2018.10.011
更新日期：2019-01-01 00:00:00
abstract：:Stereoscopic depth is most useful when it comes from relative rather than absolute disparities. However, the depth perceived from relative disparities can vary with stimulus parameters that have no connection with depth or are irrelevant to the task. We investigated observers' ability to judge the stereo depth of task...
journal_title：Vision research
pub_type： 杂志文章
doi：10.1016/j.visres.2018.08.007
更新日期：2019-05-01 00:00:00
abstract：:An observer's ability to discriminate the angular direction of a moving grating depends on the grating orientation. Observers can more accurately judge the angular direction of vertical or horizontal gratings than oblique gratings. We discovered that this oblique effect becomes very large at high spatial frequencies i...
journal_title：Vision research
pub_type： 杂志文章
doi：10.1016/0042-6989(93)90233-m
更新日期：1993-12-01 00:00:00
abstract：:The presence of retinopetal fibers in mammals has been debated many times in the past two decades. Do rabbits have a retinopetal system? This question is addressed with the present investigations. In anesthetized and paralysed rabbits the b-wave and the oscillatory potentials (OP) are recorded at the cornea. The optic...
journal_title：Vision research
pub_type： 杂志文章
doi：10.1016/0042-6989(89)90110-7
更新日期：1989-01-01 00:00:00
abstract：:In search for a singleton target, performance is considerably improved when the target and distractors repeat than when they switch roles, an effect called priming of pop-out or PoP (Maljkovic & Nakayama, 1994). Although this phenomenon has been replicated across a variety of dimensions, orientation PoP has proved to ...
journal_title：Vision research
pub_type： 杂志文章
doi：10.1016/j.visres.2013.01.008
更新日期：2013-04-05 00:00:00
abstract：:We have used DOG stimuli to selectively stimulate size tuned channels within the visual system in order to investigate the relationship between stereo and vernier acuity. We measured these acuities as a function of spatial frequency, retinal eccentricity and distance from the fixation point in depth. Both hyperacuitie...
journal_title：Vision research
pub_type： 杂志文章
doi：10.1016/0042-6989(85)90100-2
更新日期：1985-01-01 00:00:00
abstract：:To describe small scotomas in visual field examinations several statistical models are proposed and applied to the evaluation of angioscotoma in 13 ophthalmologically normal subjects. A special perimetric grid is used where thresholds can be estimated along a line of narrow-spaced test points which crosses the predict...
journal_title：Vision research
pub_type： 杂志文章
doi：10.1016/s0042-6989(98)00294-6
更新日期：1999-05-01 00:00:00
abstract：:The number and nature of spatial channels tuned to low spatial frequencies in photopic vision was examined by measuring individual differences in the contrast sensitivity functions (CSFs) of seven visually normal adults. Stationary, 51 cd/m2, low spatial frequency sinusoidal gratings between 0.27 and 2.16 c/deg were u...
journal_title：Vision research
pub_type： 杂志文章
doi：10.1016/0042-6989(96)00061-2
更新日期：1996-10-01 00:00:00
abstract：:Observers can better discriminate orientation or direction near the cardinal axes than near an oblique axis. We investigated whether this well-known oblique effect is determined by the physical or the perceived axis of the stimuli. Using the simultaneous tilt illusion, we generated perceptually different orientations ...
journal_title：Vision research
pub_type： 杂志文章
doi：10.1016/j.visres.2005.05.016
更新日期：2005-12-01 00:00:00
abstract：PURPOSE:Guinea pigs have been increasingly used as an animal model for experimental myopia. Infant guinea pigs are susceptible to recovery from myopia within 2 weeks of form deprivation. This study investigated whether adolescent guinea pigs are susceptible to recovery from myopia after a longer period of form deprivat...
journal_title：Vision research
pub_type： 杂志文章
doi：10.1016/j.visres.2007.01.002
更新日期：2007-04-01 00:00:00
abstract：:Researchers have investigated whether attentional capture during visual search is driven by top-down processes, i.e. experimental goals and directives, or by bottom-up processes, i.e. the properties of the items within a search display. Some research has demonstrated that subjects cannot avoid attending to a task-irre...
journal_title：Vision research
pub_type： 杂志文章
doi：10.1016/j.visres.2013.01.005
更新日期：2013-03-22 00:00:00
abstract：:The perceived position of a moving target at a particular point in time, indicated by a flash, is often judged to be different from its actual location. Here, we show that the position of a target moving in depth is also systematically mislocalized. We used three types of targets moving in depth at a range of speeds f...
journal_title：Vision research
pub_type： 杂志文章
doi：10.1016/j.visres.2006.01.001
更新日期：2006-09-01 00:00:00
abstract：:Observers viewed 200 msec presentations of gratings containing first (0.5 c/deg) and third (1.5 c/deg) harmonic components. The phase of the third harmonic and the absolute position of the grating on the screen varied randomly from trial to trial. Classification of the phase relation (0, 90, 180 or 270 deg was 99% per...
journal_title：Vision research
pub_type： 杂志文章
doi：10.1016/0042-6989(84)90157-3
更新日期：1984-01-01 00:00:00
abstract：:Most humans seem to demonstrate astonishingly high levels of skill in face processing if one considers the sophisticated level of fine-tuned discrimination that face recognition requires. However, numerous studies now indicate that the ability to process faces is not as fundamental as once thought and that performance...
journal_title：Vision research
pub_type： 杂志文章
doi：10.1016/j.visres.2016.07.007
更新日期：2016-10-01 00:00:00
abstract：:The sensitivity of X- and Y-cells in the dorsal lateral geniculate nucleus of the cat to small, temporally modulated displacements of grating stimuli was measured at 0.175, 0.25, 0.50, 1.00, and 2.00 c/deg. For every cell, two threshold measures were determined: first, a contrast threshold with a counterphase grating ...
journal_title：Vision research
pub_type： 杂志文章
doi：10.1016/0042-6989(86)90037-4
更新日期：1986-01-01 00:00:00
abstract：:Prior work suggests that internal features contribute more than external features to face processing. Whether this asymmetry is also true of the mental representations of faces is not known. We used face adaptation to determine whether the internal and external features of faces contribute differently to the represent...
journal_title：Vision research
pub_type： 杂志文章
doi：10.1016/j.visres.2014.04.002
更新日期：2014-07-01 00:00:00
abstract：:Temporal frequency discrimination was measured above threshold with a two-alternative spatial forced-choice procedure. Stimuli were two 1 deg homogeneous fields modulated around a mean luminance of 3.7 log trolands. Observers determined which of the two stimuli was modulated at a higher frequency. To avoid differences...
journal_title：Vision research
pub_type： 杂志文章
doi：10.1016/0042-6989(84)90020-8
更新日期：1984-01-01 00:00:00
abstract：:Electrophysiological recording demonstrated that visuo-tectal projections are topographically organised after optic nerve regeneration in aged Xenopus laevis. 3H-thymidine autoradiography confirmed previous reports [Taylor, Lack, & Easter, Eur. Journal of Neuroscience 1 (1989) 626-638] that cell division had already c...
journal_title：Vision research
pub_type： 杂志文章
doi：10.1016/s0042-6989(01)00053-0
更新日期：2001-06-01 00:00:00
abstract：:Microglia dynamically prune synaptic contacts during development, and digest waste that accumulates in degeneration and aging. In many neurodegenerative diseases, microglial activation and phagocytosis gradually increase over months or years, with poorly defined initial triggering events. Here, we describe rapid retin...
journal_title：Vision research
pub_type： 杂志文章
doi：10.1016/j.visres.2014.07.011
更新日期：2014-09-01 00:00:00
abstract：:One of the most fundamental functions of the visual system is to code the positions of objects. Most studies, especially those using fMRI, widely assume that the location of the peak retinotopic activity generated in the visual cortex by an object is the position assigned to that object-this is a simplified version of...
journal_title：Vision research
pub_type： 杂志文章
doi：10.1016/j.visres.2006.08.030
更新日期：2007-01-01 00:00:00
abstract：:The perceived blur of drifting sinusoidal gratings was compared to that of static, blurred "square wave" gratings before and after adaptation to a missing fundamental (MF) pattern. The results indicate that the perceived blur of a drifting sine grating is inversely related to its drift speed. However, after adaptation...
journal_title：Vision research
pub_type： 杂志文章
doi：10.1016/0042-6989(96)00009-0
更新日期：1996-09-01 00:00:00
abstract：:Differential spatial displacement discrimination thresholds were determined for a configuration of three identical Gaussian modulated patches of sinusoidal grating presented with equal orientation and at threshold luminance contrast. The patches were arranged one above the other at equal spatial intervals. The orienta...
journal_title：Vision research
pub_type： 杂志文章
doi：
更新日期：1988-01-01 00:00:00
abstract：:Pulses of low intensity current, delivered through a cuff electrode chronically implanted around the optic nerve of a blind retinitis pigmentosa patient generate visual sensations. These phosphenes are obtained at lower thresholds for a train of stimuli than for single pulses, which suggests the existence of a spatial...
journal_title：Vision research
pub_type： 杂志文章
doi：10.1016/s0042-6989(03)00013-0
更新日期：2003-04-01 00:00:00
abstract：:Reduced global motion sensitivity, relative to global static form sensitivity, has been found in children with many neurodevelopmental disorders, leading to the "dorsal stream vulnerability" hypothesis (Braddick et al., 2003). Individual differences in typically developing children's global motion thresholds have been...
journal_title：Vision research
pub_type： 杂志文章
doi：10.1016/j.visres.2016.09.013
更新日期：2017-12-01 00:00:00
abstract：:Edge integration refers to a hypothetical process by which the visual system combines information about the local contrast, or luminance ratios, at luminance borders within an image to compute a scale of relative reflectances for the regions between the borders. The results of three achromatic color matching experimen...
journal_title：Vision research
pub_type： 杂志文章
doi：10.1016/j.visres.2003.12.004
更新日期：2004-05-01 00:00:00
abstract：:When a colour/orientation conjunction search display is immediately preceded by a display that shows either the colour or the orientation of each upcoming search item, search is faster after colour-preview than after orientation-preview. One explanation for this feature asymmetry is that colour has priority access to ...
journal_title：Vision research
pub_type： 杂志文章
doi：10.1016/j.visres.2009.02.008
更新日期：2009-05-01 00:00:00
abstract：:Both electro-physiological and psychophysical studies point to the existence of detectors specialised for the analysis of optic flow. However, it is unclear whether these detectors are tuned to specific 'cardinal directions' (such as radial and circular motion), or whether they respond equally to all directions of opt...
journal_title：Vision research
pub_type： 杂志文章
doi：10.1016/s0042-6989(00)00276-5
更新日期：2001-02-01 00:00:00
