Rivalry Rate Research Articles

The rate of binocular rivalry -- Visual field asymmetries

At the core of the binocular rivalry phenomenon lies the spontaneous alternation between the two percepts. Understanding what drives that alternation is a major and key part of understanding the neural basis of binocular rivalry. A starting point in this direction is to characterize the factors that determine the rivalry alternation rate. It is known that some stimulus factors (e.g., contrast) can influence the rate of rivalry, here we tested whether stimuli projected to different parts of the cortex have different rivalry rates. Is there a visual field asymmetry of the rivalry dynamics? Eight near peripheral locations were tested: two eccentricity levels (1 and 4 degrees) at the four major meridians. A red circular grating and a green radius grating were dichoptically presented to the two eyes. Observers were asked to track their perceptual experience by making keypress responses to indicate which of the stimuli came into view. Results from 10 observers (two authors and eight naive observers) show that the alternation rate in binocular rivalry is faster when the stimuli were presented to the right visual field compared to when they were presented to the left visual field. Similarly, rival stimuli in the lower visual field generated faster alternations than that in the upper visual field. There are a number of potential reasons that can lead to the observed rivalry asymmetry. For example, visual attention maybe biased towards the lower and the right visual fields, or at the site of binocular rivalry, the time course of neuronal responses could be faster for information from the lower and right visual fields than that from the upper and left visual fields. In any case, this visual field dependence suggests that the process of binocular rivalry is influenced by retinotopically specific mechanisms.

Genetic contribution to individual variation in binocular rivalry rate

Binocular rivalry occurs when conflicting images are presented in corresponding locations of the two eyes. Perception alternates between the images at a rate that is relatively stable within individuals but that varies widely between individuals. The determinants of this variation are unknown. In addition, slow binocular rivalry has been demonstrated in bipolar disorder, a psychiatric condition with high heritability. The present study therefore examined whether there is a genetic contribution to individual variation in binocular rivalry rate. We employed the twin method and studied both monozygotic (MZ) twins (n = 128 pairs) who are genetically identical, and dizygotic (DZ) twins (n = 220 pairs) who share roughly half their genes. MZ and DZ twin correlations for binocular rivalry rate were 0.51 and 0.19, respectively. The best-fitting genetic model showed 52% of the variance in binocular rivalry rate was accounted for by additive genetic factors. In contrast, nonshared environmental influences accounted for 18% of the variance, with the remainder attributed to measurement error. This study therefore demonstrates a substantial genetic contribution to individual variation in binocular rivalry rate. The results support the vigorous pursuit of genetic and molecular studies of binocular rivalry and further characterization of slow binocular rivalry as an endophenotype for bipolar disorder.

Corrigendum

Bipolar DisordersVolume 11, Issue 6 p. 672-672 Free Access Corrigendum This article corrects the following: Difference in binocular rivalry rate between patients with bipolar I and bipolar II disorders Masanori Nagamine, Aihide Yoshino, Masaki Miyazaki, Yoshitomo Takahashi, Soichiro Nomura, Volume 11Issue 5Bipolar Disorders pages: 539-546 First Published online: July 10, 2009 First published: 10 August 2009 https://doi.org/10.1111/j.1399-5618.2009.00740.xAboutSectionsPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat In (1) on p. 544, there is an error in the listing of a reference and the authors of that reference. On line 5, the correct sentence should read: Recently, Krug et al. used more precise methods and found that patients with bipolar disorder exhibit slow perceptual switching when they are presented with ambiguous structure-from-motion figures. Correct reference: Krug K, Brunskill E, Scarna A, Goodwin GM, Parker AJ. Perceptual switch rates with ambiguous structure-from-motion figures in bipolar disorder. Proc Biol Sci 2008; 275: 1839-1848. Reference 1 Nagamine M, Yoshino A, Miyazaki M, Takahashi Y, Nomura S. Difference in binocular rivalry rate between patients with bipolar I and bipolar II disorders. Bipolar Disord 2009; 11: 539– 546. Wiley Online LibraryCASPubMedWeb of Science®Google Scholar We apologize for this error. Volume11, Issue6September 2009Pages 672-672 ReferencesRelatedInformation

Difference in binocular rivalry rate between patients with bipolar I and bipolar II disorders

When dissimilar figures are presented to each eye individually, perception alternates spontaneously between each monocular view. This phenomenon, known as binocular rivalry, has been used as a powerful tool to investigate conscious visual awareness. Of clinical relevance, Pettigrew and Miller (Proc Biol Sci 1998; 265: 2141-2148) found slow perceptual alternation rates in patients with bipolar I disorder (BD-I). For a better understanding of differences between BD-I and bipolar II disorder (BD-II), we examined whether perceptual alternation rates of binocular rivalry differ between the two subtypes of bipolar disorder. The subjects comprised 25 healthy controls, 11 patients with BD-I, and 17 patients with BD-II. They underwent binocular rivalry examination. One-way analysis of variance was conducted to determine differences in the phase duration of binocular rivalry between the control, BD-I, and BD-II groups. Significant differences were observed in the mean phase duration of binocular rivalry between the groups. Although the medication administered did not differ significantly between the BD-I and BD-II patients, the phase duration was significantly longer among the BD-I patients than the BD-II patients and controls, whereas no significant difference was observed in the phase duration between the BD-II patients and controls. The present results reveal a significant difference in the mean phase duration of binocular rivalry between subjects with BD-I and those with BD-II, suggesting the presence of some neurobiological difference between these two subtypes of bipolar disorder.

Binocular interactions in patients with age-related macular degeneration: Acuity summation and rivalry

This study examined two aspects of binocular function in patients with age-related macular degeneration (AMD): summation/inhibition of visual acuity and rivalry. The performance of 17 patients with AMD was compared with that of 17 elderly controls and 21 young people. Monocular and binocular acuities were measured using a multiple-E optotype test. Binocular ratios, defined as the better-eye acuity divided by the binocular acuity, were calculated. We also measured eye dominance during rivalry (proportion of time the participants reported perceiving the input to each eye) and rivalry rates (number of alternations per minute). The results showed that while overall binocular ratios were similar for the three groups, the frequency distributions of people who experienced inhibition, equality or summation were different for the young and AMD groups. In the rivalry test, patients experienced more piecemeal perception than the elderly and young controls, but time dominance from the better-seeing eye was comparable for the three groups. Rivalry rates decreased with age and further with pathology. Moreover, rivalry time dominance of the worse-seeing eye was negatively correlated with interocular acuity differences for the AMD group.

A 'sticky' interhemispheric switch in bipolar disorder?

Despite years of research into bipolar disorder (manic depression), its underlying pathophysiology remains elusive. It is widely acknowledged that the disorder is strongly heritable, but the genetics are complex with less than full concordance in monozygotic twins and at least four susceptibility loci identified. We propose that bipolar disorder is the result of a genetic propensity for slow interhemispheric switching mechanisms that become 'stuck' in one or the other state. Because slow switches are also 'sticky' when compared with fast switches, the clinical manifestations of bipolar disorder may be explained by hemispheric activation being 'stuck' on the left (mania) or on the right (depression). Support for this 'sticky' interhemispheric switching hypothesis stems from our recent observation that the rate of perceptual alternation in binocular rivalry is slow in euthymic subjects with bipolar disorder (n = 18, median = 0.27 Hz) compared with normal controls (n = 49, median = 0.60 Hz, p < 0.0005). We have presented evidence elsewhere that binocular rivalry is itself an interhemispheric switching phenomenon. The rivalry alternation rate (putative interhemispheric switch rate) is robust in a given individual, with a test-retest correlation of more than 0.8, making it suitable for genetic studies. The interhemispheric switch rate may provide a trait-dependent biological marker for bipolar disorder.

The dependence of monocular rivalry on spatial frequency: some interaction variables.

The effect of spatial frequency upon the rate of monocular rivalry has been investigated on several occasions, with conflicting results. With increases in spatial frequency the rivalry rate has been variously reported as declining monotonically, increasing slightly and briefly before declining sharply, or showing a sharp increase before a sharp decrease. Experiments are reported which show that all three functions may be obtained depending on whether the number of cycles of the gratings is held constant across spatial frequency, or the field size is held constant (and, if the latter, what field size is used). The point at which any high-frequency decline occurs is also shown to increase with increasing luminance. All functions obtained correspond to visual sensitivity functions obtained under comparable conditions.

Angular selectivity of monocular rivalry: Experiment and computer simulation

The angular selectivity of monocular rivalry (MR) was re-examined with achromatic gratings (4 c/deg, 10% contrast). Various measures of rivalry rate and duration all gave the same result: MR increased linearly for angles up to 60° and was constant thereafter, but the duration of a bout of rivalry was invariant with angle. Absolute orientation (vertical vs oblique) had no effect. It is proposed that MR occurs when eye movements produce partial cancellations between the stimulus pattern and its negative after-image. Computer simulation shows that this model can account for almost all the results in the literature and therefore suggests that MR does not reveal the nature of visual pattern-analyzing mechanisms.

Reporting of Fragmentations in the Binocular Rivalry of Contours

Male and female college students reported changes for 5 min while observing rivalry or pseudo rivalry (sequences of rivalrylike stimulus changes) with or without fragmentations, under rapid-rate, natural-rate, or slow-rate instructions; firstand second-grade girls had only natural-rate instructions. Differences in rivalry rates were not related to response mechanisms and may be presumed to reflect perceptual differences. Age, sex, instruction, and temporal variables affected rivalry independently.

The stability of binocular rivalry during spaced and massed viewing

The purpose of the study was consideration of the stability of binocular rivalry rates during extended periods of spaced and massed viewing by untrained observers. In Experiment I no relationship was found between eyeblink rates and rivalry rates, and a visual vigilance task reported simultaneously with rivalry reporting proved to be a useful indicator that Ss maintained attention during the viewing period; the vigilance task did not disrupt rivalry data. In Experiment II Ss reported rivalry during 10 min. of continuous or 10 min. of non-continuous viewing on each of three consecutive days. The vigilance task was presented to all Ss. After the first minute of viewing, during which conditions were alike for all Ss and rivalry rates differed only slightly, the rates of the Spaced Groups increased while the rates of the Massed Groups showed little variation.

A DEVELOPMENTAL STUDY OF RETINAL RIVALRY.

In a developmental study of retinal rivalry, 141 Ss were each tested for 3 consecutive minutes. Male and female Ss were selected from kindergarten, 2nd, 4th, 5th, 6th grades, and college students. The rivalry stimulus was a monocular horizontal line and a monocular vertical line (approximately 1 mm. retinal size). Reliability of Ss' report was checked using a simulated rivalry technique. Rivalry rate increased significantly as a function of age, and females' rates were higher at every age tested.

EFFECT OF AROUSAL AND INTELLIGENCE ON BINOCULAR RIVALRY RATE.

Variation in rate of binocular rivalry alternation was measured in 40 undergraduate males as a function of physiological arousal induced by threat of shock and as a function of differences in verbal intelligence. Neither variable was related to changes in rate. Visual acuity and phoria were not correlated with rate. Temporal reliability of rate was on the order of .90. For all Ss rate increased significantly over trials ( p &lt; .01). Interpretations of these data are discussed.

ON THE INTERRELATIONSHIP OF BINOCULAR RIVALRY RATE AND INSTRUCTIONS.

The results of a factor analysis of mean numbers of binocular rivalry reversals perceived by 24 Ss under various instructions are suggestive of further factor analytic work needed in the domain of visual perception, especially reversibility phenomena.