Cutaneous Rabbit Research Articles

A Bayesian Perceptual Model Replicates the Cutaneous Rabbit and Other Tactile Spatiotemporal Illusions

BackgroundWhen brief stimuli contact the skin in rapid succession at two or more locations, perception strikingly shrinks the intervening distance, and expands the elapsed time, between consecutive events. The origins of these perceptual space-time distortions are unknown.Methodology/Principal FindingsHere I show that these illusory effects, which I term perceptual length contraction and time dilation, are emergent properties of a Bayesian observer model that incorporates prior expectation for speed. Rapidly moving stimuli violate expectation, provoking perceptual length contraction and time dilation. The Bayesian observer replicates the cutaneous rabbit illusion, the tau effect, the kappa effect, and other spatiotemporal illusions. Additionally, it shows realistic tactile temporal order judgment and spatial attention effects.Conclusions/SignificanceThe remarkable explanatory power of this simple model supports the hypothesis, first proposed by Helmholtz, that the brain biases perception in favor of expectation. Specifically, the results suggest that the brain automatically incorporates prior expectation for speed in order to overcome spatial and temporal imprecision inherent in the sensorineural signal.

The Cutaneous Rabbit Illusion Affects Human Primary Sensory Cortex Somatotopically

We used functional magnetic resonance imaging (fMRI) to study neural correlates of a robust somatosensory illusion that can dissociate tactile perception from physical stimulation. Repeated rapid stimulation at the wrist, then near the elbow, can create the illusion of touches at intervening locations along the arm, as if a rabbit hopped along it. We examined brain activity in humans using fMRI, with improved spatial resolution, during this version of the classic cutaneous rabbit illusion. As compared with control stimulation at the same skin sites (but in a different order that did not induce the illusion), illusory sequences activated contralateral primary somatosensory cortex, at a somatotopic location corresponding to the filled-in illusory perception on the forearm. Moreover, the amplitude of this somatosensory activation was comparable to that for veridical stimulation including the intervening position on the arm. The illusion additionally activated areas of premotor and prefrontal cortex. These results provide direct evidence that illusory somatosensory percepts can affect primary somatosensory cortex in a manner that corresponds somatotopically to the illusory percept.

The cutaneous rabbit revisited.

In the cutaneous rabbit effect (CRE), a tactile event (so-called attractee tap) is mislocalized toward an adjacent attractor tap. The effect depends on the time interval between the taps. The authors delivered sequences of taps to the forearm and asked participants to report the location of one of the taps. The authors replicated the original CRE findings and observed a smaller but significant mislocalization when the attractor tap preceded the attractee tap. These results are consistent with the CRE arising from spatiotemporal interactions between the sensory codes for each individual tap. In subsequent experiments, the authors showed that the CRE was not affected by either gaze direction or concurrent auditory temporal information. The authors propose a model that explains the CRE by the spatiotemporal dynamics of an early, unimodal, sensory map.

Large cutaneous rabbit papillomas that persist during cyclosporin A treatment can regress spontaneously after cessation of immunosuppression

Cottontail rabbit papillomavirus (CRPV)-induced papillomas can progress into malignant carcinomas, remain persistent or regress. Both host immunity and virus genetic background play critical roles in these events. To test how host immunity influences CRPV-induced papilloma evolution, both EIII/JC (inbred) and New Zealand White (outbred) rabbits were treated with an immunosuppressive drug, cyclosporin A (CsA), for 80 days and the regression of three regressive constructs, H.CRPVr (a CRPV regressive strain), H.CRPVp-E6r (a progressive strain with regressive E6) and H.CRPVp-CE6rm (H.CRPVp with the carboxyl terminal of regressive E6, containing mutations at amino acid residues E252G, G258D and S259P) was checked. Papillomas induced by H.CRPVr and H.CRPVp-E6r on control inbred and outbred rabbits regressed totally around week 8, whereas papillomas on all CsA-treated rabbits grew progressively. After cessation of CsA treatment, papillomas began to regress in six outbred rabbits: 14 of 18 papillomas induced by CRPVr, 11 of 18 papillomas induced by H.CRPVp-E6r and eight of 10 papillomas induced by H.CRPVp-CE6rm regressed around week 21. In four CsA-treated inbred rabbits, two of 17 papillomas induced by H.CRPVr and one of 17 papillomas induced by H.CRPVp-E6r regressed. These data indicate that papillomas induced by a regressive CRPV strain can become persistent in the transiently immunosuppressed host. However, returning immunity can lead to regression and clearance of large papillomas (with increased antigenicity) in an outbred population, whilst these same antigenic papillomas persist in inbred rabbits.

Topical effects of cidofovir on cutaneous rabbit warts: treatment regimen and inoculum dependence

The present study examined topical effects of cidofovir on cutaneous rabbit warts. Based on an inoculum-dependency study, each New Zealand White rabbit was inoculated with a high and low titer of cottontail rabbit papillomavirus (CRPV) at four sites on each dorsolateral area. Inoculation with 50 ID 50 induced papillomas at 100% of the inoculation sites within 16±1 days, and the wart growth curve plateaued within ∼7 weeks. With an inoculum of 5 ID 50, 80% of the inoculated sites developed papillomas within 21±1 days and their size plateaued at a later time. Cidofovir was applied topically twice daily on the inoculated sites at a concentration of 1% for 18 days, starting at three different time points. In the first experiment, treatment was initiated 7 days post-inoculation. One of the inoculated sides received cidofovir or the vehicle, PBS, while the other side was left untreated. With this treatment regimen, cidofovir significantly delayed the time of onset and the growth rate of papillomas induced with the high titer of inoculum. It completely prevented papilloma-induction on the sites inoculated with the low titer of CRPV. Reversible side-effects of cidofovir were observed on the directly treated area including erythema, necrosis, and flaking. Both therapeutic and side-effects were limited to the sites of direct exposure. In the second experiment, one of the two sides in each group of rabbits received cidofovir or vehicle starting on day 29 post-inoculation. With this treatment regimen, cidofovir significantly reduced wart growth against the low titer only. Topical treatment initiated on day 49 post-inoculation was not effective on warts initiated with either viral titer. These results demonstrated that topical cidofovir could be very effective against papillomavirus-induced wart growth if it is initiated early during the infection, especially against low titers of inoculum.

The Effect of Cooling on the Contractile Response to Endothelin-1 in Small Arteries from Humans

The pathogenesis of the prolonged cold-induced vasospasm of Raynaud's disease (RD) is unknown. Cooling has been shown to decrease the sensitivity of cutaneous rabbit ear arteries to endothelin-1 (ET-1), perhaps by increasing the availability of nitric oxide (NO). If the endothelium in RD lacks this NO-mediated inhibitory function during cooling, increased production and enhanced constriction to ET-1 could cause vasospasm. This study examined the effect of cooling on the contractile response to ET-1 in human microvessels. Small arteries were dissected from biopsy specimens of human fat and were cannulated in a small vessel arteriograph. Cumulative concentration-response curves to ET-1 (10(-12) to 3 x 10(-7) M) were obtained in vessels at 37 degrees C (n = 8) and 24 degrees C (n = 7). Cooling to 24 degrees C resulted in an eightfold decrease in sensitivity to ET-1 (EC50 6.6 +/- 2.5 x 10(-10) M at 37 degrees C vs. 5.5 +/- 2.5 x 10(-9) M at 24 degrees C; p < 0.05, unpaired t test). The Emax was not significantly different at 37 degrees C and 24 degrees C (114 +/- 9 at 37 degrees C vs. 138 +/- 14 at 24 degrees C; p = 0.18). These results suggest that cooling decreases the sensitivity of human microvessels to ET-1. Further investigation is needed to establish the mechanism of this effect, including studies in vessels obtained from patients with RD.

Time and the observer: The where and when of consciousness in the brain

AbstractWe compare the way two models of consciousness treat subjective timing. According to the standard “Cartesian Theater” model, there is a place in the brain where “it all comes together,” and the discriminations in all modalities are somehow put into registration and “presented” for subjective judgment. The timing of the events in this theater determines subjective order. According to the alternative “Multiple Drafts” model, discriminations are distributed in both space and time in the brain. These events do have temporal properties, but those properties do not determine subjective order because there is no single, definitive “stream of consciousness,” only a parallel stream of conflicting and continuously revised contents. Four puzzling phenomena that resist explanation by the Cartesian model are analyzed: (1) a gradual apparent motion phenomenon involving abrupt color change (Kolers &amp; von Grünau 1976), (2) an illusion of an evenly spaced series of “hops” produced by two or more widely spaced series of taps delivered to the skin (Geldard &amp; Sherrick's “cutaneous rabbit” [1972]), (3) backwards referral in time, and (4) subjective delay of consciousness of intention (both reported in this journal by LIbet 1985a; 1987; 1989a). The unexamined assumptions that have always made the Cartesian Theater so attractive are exposed and dismantled. The Multiple Drafts model provides a better account of the puzzling phenomena, avoiding the scientific and metaphysical extravagances of the Cartesian Theater: The temporal order of subjective events is a product of the brain's interpretational processes, not a direct reflection of events making up those processes.

The perception of distance and location for dual tactile pressures

The concept that distance on the skin is frequently misperceived was first reported over a century ago by Weber. Weber and others have reported that the apparent distance between pressure stimuli fluctuates with both body site and stimulus orientation. The present study confirms these effects and shows that the misperceptions are usually compressive in nature. It further establishes that errors in perceived distance correspond to errors in perceived location, indicating that an interaction exists between the perceptual processes responsible for percepts of tactile location and distance. Perceived location depends on the relationship of a tactile stimulus both to the body frame and to nearby stimuli, and the effect of nearby stimuli is to induce a perceptual affinity between sensations of pressure. These results are discussed in relation to the more frequently examined dynamic illusions of tactile distance (tau phenomenon) and location (the cutaneous rabbit).

Temporal dispersion in cortical response.

ArticlesTEMPORAL DISPERSION IN CORTICAL RESPONSEW. R. Adey, I. D. Carter, and R. PorterW. R. Adey, I. D. Carter, and R. PorterPublished Online:01 Mar 1954https://doi.org/10.1152/jn.1954.17.2.167MoreSectionsPDF (2 MB)Download PDF ToolsExport citationAdd to favoritesGet permissionsTrack citations ShareShare onFacebookTwitterLinkedInWeChat Previous Back to Top Next Download PDF FiguresReferencesRelatedInformation Cited ByThe cutaneous rabbit revisited.1 January 2006 | Journal of Experimental Psychology: Human Perception and Performance, Vol. 32, No. 3Integrative Properties of Parastriate NeuronsMultiple use of the auditory cortex: Interaction at a single pointExperimental Neurology, Vol. 34, No. 1Crossed Temperature Discrimination Following Section of Forebrain Neocortical CommissuresCortex, Vol. 6, No. 4ReferencesComparative Physiology of MarsupialsNeural limitations of visual excitability V. Cerebral after-activity evoked by photic stimulationVision Research, Vol. 4, No. 3-4Laterality effects in somesthesis following cerebral commissurotomy in manNeuropsychologia, Vol. 1, No. 3ReferencesActa Physiologica Scandinavica, Vol. 56Short and long latency cortical responses to somesthetic stimulation in the catExperimental Neurology, Vol. 4, No. 6Representation of locality in a biological information systemThe Bulletin of Mathematical Biophysics, Vol. 20, No. 3 More from this issue > Volume 17Issue 2March 1954Pages 167-182 https://doi.org/10.1152/jn.1954.17.2.167PubMed13143418History Published online 1 March 1954 Published in print 1 March 1954 Metrics

PRODUCTION OF EXPERIMENTAL TUMORS OF THE BRAIN WITH THE SHOPE RABBIT PAPILLOMA II

The gross characteristics of extradural and subdural growths produced by implantation of virus-induced cutaneous rabbit papilloma 1 and the reaction of the brain to such experimental tumors have been described briefly. 2 It was noted in a small series of implantations that the intracranial growths were essentially similar to those observed following implantation in other tissues of the host. The proliferating epithelium of the individual growths did not invade the adjacent nerve tissue, and the growths thus presented the picture of slowly expanding intracranial tumors. Histologic study showed that there was no glial reaction when implantation was extradural and a layer of meninges was interposed between the tumor and the brain. When, on the other hand, the tumor was implanted subdurally, thus coming into more direct contact with the parenchyma of the brain, there was always proliferation of astrocytes with formation of numerous fibers, which were attached to the tumor