Filling-in Effect Research Articles

Causality and continuity close the gaps in event representations.

Imagine you see a video of someone pulling back their leg to kick a soccer ball, and then a soccer ball soaring toward a goal. You would likely infer that these scenes are two parts of the same event, and this inference would likely cause you to remember having seen the moment the person kicked the soccer ball, even if that information was never actually presented (Strickland & Keil, 2011, Cognition, 121[3], 409-415). What cues trigger people to "fill in" causal events from incomplete information? Is it due to the experience they have had with soccer balls being kicked toward goals? Is it the visual similarity of the object in both halves of the video? Or is it the mere spatiotemporal continuity of the event? In three experiments, we tested these different potential mechanisms underlying the "filling-in" effect. Experiment 1 showed that filling in occurs equally in familiar and unfamiliar contexts, indicating that familiarity with specific event schemas is unnecessary to trigger false memory. Experiment 2 showed that the visible continuation of a launched object's trajectory is all that is required to trigger filling in, regardless of other occurrences in the second half of the scene. Finally, Experiment 3 found that, using naturalistic videos, this filling-in effect is more heavily affected if the object's trajectory is discontinuous in space/time compared with if the object undergoes a noticeable transformation. Together, these findings indicate that the spontaneous formation of causal event representations is driven by object representation systems that prioritize spatiotemporal information over other object features.

A Compound Computational Model for Filling-In Processes Triggered by Edges: Watercolor Illusions.

The goal of our research was to develop a compound computational model with the ability to predict different variations of the “watercolor effects” and additional filling-in effects that are triggered by edges. The model is based on a filling-in mechanism solved by a Poisson equation, which considers the different gradients as “heat sources” after the gradients modification. The biased (modified) contours (edges) are ranked and determined according to their dominancy across the different chromatic and achromatic channels. The color and intensity of the perceived surface are calculated through a diffusive filling-in process of color triggered by the enhanced and biased edges of stimulus formed as a result of oriented double-opponent receptive fields. The model can successfully predict both the assimilative and non-assimilative watercolor effects, as well as a number of “conflicting” visual effects. Furthermore, the model can also predict the classic Craik–O'Brien–Cornsweet (COC) effect. In summary, our proposed computational model is able to predict most of the “conflicting” filling-in effects that derive from edges that have been recently described in the literature, and thus supports the theory that a shared visual mechanism is responsible for the vast variety of the “conflicting” filling-in effects that derive from edges.

Noise and the Perceptual Filling-in effect.

Nearby collinear flankers increase the false alarm rate (reports of the target being present when it is not) in a Yes-No experiment. This effect has been attributed to “filling-in” of the target location due to increased activity induced by the flankers. According to signal detection theory, false alarms are attributed to noise in the visual nervous system. Here we investigated the effect of external noise on the filling-in effect by adding white noise to a low contrast Gabor target presented between two collinear Gabor flankers at a range of target-flanker separations. External noise modulates the filling-in effect, reducing visual sensitivity (d′) and increasing the filling-in effect (False Alarm rate). We estimated the amount of external noise at which the false alarm rate increases by the √2 (which we refer to as NFA). Across flank distances, both the false alarm rate and d′ (with no external noise) are correlated with NFA. These results are consistent with the notion that nearby collinear flankers add both signal and noise to the target location. The increased signal results in higher d′ values; the increased noise to higher false alarm rates (the filling effect).

Note on rotational-Raman scattering in the O<sub>2</sub> A- and B-bands

Abstract. Quantifying the impact of rotational-Raman scattering (RRS) on the O2 A- and B-bands is important as these bands can be used for cloud and aerosol characterization for trace-gas retrievals including CO2 and CH4. In this paper, we simulate the spectral effects of RRS for various viewing geometries and instruments with different spectral resolutions. We also examine how aerosols affect the amount of RRS filling-in. We show that the filling-in effects of RRS are relatively small, but not negligible, in these O2 absorption bands, particularly for high-spectral-resolution instruments. For comparison, we also compare and contrast the spectral signatures of RRS with those of terrestrial chlorophyll fluorescence.

Is interpolation cognitively encapsulated? Measuring the effects of belief on Kanizsa shape discrimination and illusory contour formation

Contour interpolation is a perceptual process that fills-in missing edges on the basis of how surrounding edges (inducers) are spatiotemporally related. Cognitive encapsulation refers to the degree to which perceptual mechanisms act in isolation from beliefs, expectations, and utilities (Pylyshyn, 1999). Is interpolation encapsulated from belief? We addressed this question by having subjects discriminate briefly-presented, partially-visible fat and thin shapes, the edges of which either induced or did not induce illusory contours (relatable and non-relatable conditions, respectively). Half the trials in each condition incorporated task-irrelevant distractor lines, known to disrupt the filling-in of contours. Half of the observers were told that the visible parts of the shape belonged to a single thing (group strategy); the other half were told that the visible parts were disconnected (ungroup strategy). It was found that distractor lines strongly impaired performance in the relatable condition, but minimally in the non-relatable condition; that strategy did not alter the effects of the distractor lines for either the relatable or non-relatable stimuli; and that cognitively grouping relatable fragments improved performance whereas cognitively grouping non-relatable fragments did not. These results suggest that (1) filling-in effects during illusory contour formation cannot be easily removed via strategy; (2) filling-in effects cannot be easily manufactured from stimuli that fail to elicit interpolation; and (3) actively grouping fragments can readily improve discrimination performance, but only when those fragments form interpolated contours. Taken together, these findings indicate that discriminating filled-in shapes depends on strategy but the filling-in process itself may be encapsulated from belief.

Excitatory repetitive transcranial magnetic stimulation over the dorsolateral prefrontal cortex does not affect perceptual filling-in in healthy volunteers

Collinear flankers increase the reports of the target present, an effect attributed to excitatory activation induced by the flankers on the target location, which consequently induces the filling-in effect ( Polat & Sagi, 2007). Repetitive transcranial magnetic stimulation (rTMS) is a powerful tool for non-invasive investigation of neural processing in the human brain. We explored how rTMS over the left dorsolateral prefrontal cortex (LDLPFC) affects filling-in perception in normal controls. Active and Sham rTMS were used over the DLPFC (90% of the subjects’ motor threshold (MT)) using 10-Hz pulses for 5- and 20-s intertrain intervals. We used the filling-in paradigm to probe hit rates (pHit) and false-positive reports (false alarm, pFA). We found that the changes in the filling-in effect (pHit, pFA) were not significantly different between the groups. However, the reaction time (RT) was significantly reduced in the rTMS group but not in the Sham group. Our results suggest that neural processing in this area is not critical in the processing of the filling-in effect, probably because this process is mediated by lower-level visual processing.

Preenchimento perceptivo da mancha cega não distorce a percepção do tamanho linear

Ao se olhar o mundo monocularmente, não se percebe que há uma mancha cega no campo visual correspondente ao disco óptico, região da retina em que não há fotorreceptores. Ao contrário, bordas e padrões de superfícies são percebidos como se fossem detectados por fotorreceptores, fenômeno denominado preenchimento perceptivo. Para investigar se o preenchimento perceptivo distorce o espaço percebido, trinta adultos tiveram suas manchas cegas do olho direito mapeadas e fizeram as comparações de tamanho de pares de barras horizontais em condição monocular direita. Os resultados apontam uma assimetria lateral no campo visual central do olho direito nas comparações de tamanho e que o preenchimento perceptivo na mancha cega não distorce o espaço visual percebido.

Measuring and modeling filling-in effects in retinal AMD scotomas

Measuring and modeling filling-in effects in retinal AMD scotomas

Dense optical flow via robust data fusion

Locally optimised differential methods for computing optical flow have the merit of being faster and more reliable under noise when compared to their globally optimised counterparts. However, they produce sparse flow estimates as a result of being unable to deal with local image regions of little texture. They are also particularly inefficient for regions whose change of feature-constancy function is highly nonlinear. In this study, we treat several limitations of the local approach in monochrome images. We present a robust H∞ data fusion-based framework to propagate flow information from high confidence regions to those suspected of poor quality estimates. The adopted data fusion engine is tolerant towards uncertainty and error inherited in the optical flow computation process. A new integrated confidence measure is also presented to predict the accuracy of the recovered flow across the image enabling the data fusion engine to work as an intelligent filling-in effect, not only when the intensity is problematic but also for other uncertain regions. Results demonstrate the significance of the proposed method.

Microsaccades counteract perceptual filling-in

Artificial scotomas positioned within peripheral dynamic noise fade perceptually during visual fixation (that is, the surrounding dynamic noise appears to fill-in the scotoma). Because the scotomas' edges are continuously refreshed by the dynamic noise background, this filling-in effect cannot be explained by low-level adaptation mechanisms (such as those that may underlie classical Troxler fading). We recently showed that microsaccades counteract Troxler fading and drive first-order visibility during fixation (S. Martinez-Conde, S. L. Macknik, X. G. Troncoso, & T. A. Dyar, 2006). Here we set out to determine whether microsaccades may counteract the perceptual filling-in of artificial scotomas and thus drive second-order visibility. If so, microsaccades may not only counteract low-level adaptation but also play a role in higher perceptual processes. We asked subjects to indicate, via button press/release, whether an artificial scotoma presented on a dynamic noise background was visible or invisible at any given time. The subjects' eye movements were simultaneously measured with a high precision video system. We found that increases in microsaccade production counteracted the perception of filling-in, driving the visibility of the artificial scotoma. Conversely, decreased microsaccades allowed perceptual filling-in to take place. Our results show that microsaccades do not solely overcome low-level adaptation mechanisms but they also contribute to maintaining second-order visibility during fixation.

Exaggerated Color Perception in a Patient with Visual Form Agnosia

Previous studies on visual form agnosic patients have shown that their color perception is relatively preserved when monochromatic figures are used. However, it is unclear whether their color perception remains normal when figures are composed of two parts in different colors. The results showed that patient X.F. had difficulty in naming both colors when the two colors were placed next to each other, and in discriminating the two-color figure from the figure presented in its larger color. In contrast, X.F. could name the two colors when they were physically separated. These data suggest that X.F. manifests exaggerated color perception, producing a color filling-in effect that may be mediated by her spared early visual area.

Discrete-ordinate radiative transfer in a stratified medium with first-order rotational Raman scattering

Rotational Raman scattering (RRS) by air molecules in the Earth's atmosphere is predominantly responsible for the Ring effect: Fraunhofer and absorption-feature filling-in observed in UV/visible backscatter spectra. Accurate determination of RRS effects requires detailed radiative transfer (RT) treatment. In this paper, we demonstrate that the discrete-ordinate RT equations may be solved analytically in a multi-layer multiple scattering atmosphere in the presence of RRS treated as a first-order perturbation. Based on this solution, we develop a generic pseudo-spherical RT model LIDORT-RRS for the determination of backscatter radiances with RRS included; the model will generate output at arbitrary viewing geometry and optical thickness. Model comparisons with measured RRS filling-in effects from OMI observations show very good agreement. We examine telluric RRS filling-in effects for satellite-view backscatter radiances in a spectral range covering the ozone Huggins absorption bands. The model is also used to investigate calcium H and K Fraunhofer filling-in through cloud layers in the atmosphere.

Construction investments and economic growth in Western Europe

The research task in the present study is to examine the statistical relationship between gross domestic product and a broad group of construction and, furthermore, the presence of crowding-out within the construction industry in Europe. The empirical analyzes support the findings of no crowding-out effect within the construction industry. Contrary, it seems that investments in especially infrastructure will have a complementary filling-in effect by an increase in both residential and other building construction. The Granger causality tests are not conclusive. However, the results imply that GDP Granger cause total construction in the short run, but not vice versa. Furthermore, infrastructure investments Granger causes GDP in the short run. The overall conclusion is that public infrastructure policies have an effect on short-run economic growth but only a weak effect on the long run and that there exist a filling-in effect from other types of construction. Furthermore, residential construction does have a long-run effect on economic growth.

Comparison of dynamical model atmospheres of Mira variables with mid-infrared interferometric and spectroscopic observations

We present a comparison of dynamical model atmospheres with mid-infrared (~11 micron) interferometric and spectroscopic observations of the Mira variable o Cet. The dynamical model atmospheres of Mira variables pulsating in the fundamental mode can fairly explain, without assuming ad-hoc components, the seemingly contradictory mid-infrared spectroscopic and interferometric observations of o Cet: the 11 micron sizes measured in the bandpass without any salient spectral features are about twice as large as those measured in the near-infrared. Our calculations of synthetic spectra show that the strong absorption due to a number of optically thick H2O lines is filled in by the emission of these H2O lines originating in the geometrically extended layers, providing a possible physical explanation for the picture proposed by Ohnaka (2004a) based on a semi-empirical modeling. This filling-in effect results in rather featureless, continuum-like spectra in rough agreement with the observed high-resolution 11 micron spectra, although the models still predict the H2O lines to be more pronounced than the observations. The inverse P-Cyg profiles of some strong H2O lines observed in the 11 micron spectra can also be reasonably reproduced by our dynamical model atmospheres. The presence of the extended H2O layers manifests itself as mid-infrared angular diameters much larger than the continuum diameter. The 11 micron uniform-disk diameters predicted by our dynamical model atmospheres are in fair agreement with those observed with the Infrared Spatial Interferometer (ISI), but still somewhat smaller than the observed diameters. We discuss possible reasons for this discrepancy and problems with the current dynamical model atmospheres of Mira variables.

Filling-in of visual phantoms in the human brain

The constructive nature of perception can be demonstrated under viewing conditions that lead to vivid subjective impressions in the absence of direct input. When a low-contrast moving grating is divided by a large gap, observers report seeing a 'visual phantom' of the real grating extending through the blank gap region. Here, we report fMRI evidence showing that visual phantoms lead to enhanced activity in early visual areas that specifically represent the blank gap region. We found that neural filling-in effects occurred automatically in areas V1 and V2, regardless of where the subject attended. Moreover, when phantom-inducing gratings were paired with competing stimuli in a binocular rivalry display, subjects reported spontaneous fluctuations in conscious perception of the phantom accompanied by tightly coupled changes in early visual activity. Our results indicate that phantom visual experiences are closely linked to automatic filling-in of activity at the earliest stages of cortical processing.

Neon Color Spreading Promoted by Motion Information

We conducted experiments to investigate the effects of head-motion and object-motion to produce a perception of neon color spreading. Our experimental results indicated that a two-dimensional motion of yellow patches promoted the color spreading. A horizontal head-motion with motion parallax and three-dimensional pictorial depth information together with changing the viewing point stimulated the color spreading even, more than the two-dimensional motion. Thus, motion signals appear to offer useful information for the formation of a subjective contour and/or to activate the filling-in effect needed to generate neon color spreading. We also tested whether there was a difference between the effects of vertical and horizontal motion parallaxes for neon color spreading and found that there was none. This suggests that vertical head motion provides information in depth and surface perception equivalent to horizontal head motion.

Diurnal variation of the linear polarization across the H? Fraunhofer line of the terrestrial atmosphere, I

When spectra of the daytime sky are compared with those directly from the Sun, it is found that the depths of the Fraunhofer lines are reduced. This indicates the presence of an added light, the Ring effect. Most previous research on the Ring effect has been performed spectroscopically, with the notion that the added component is always unpolarized. Here we presented spectropolarimetric observations using the principle of the line depth method (compression between the line centre and its continuum) to investigate this effect. The general scattered light of the blue sky is polarized and as the additional component may or may not also be polarized, the filling-in effect should be detectable by performing spectropolarimetry, which indeed has been achieved. The observations have involved the use of high precision polarimetry with spectral resolution ≈ 2 A at the Hβ Fraunhofer spectral line. The data indicate a variation of the linear polarization in the Hβ line centre as a function of the solar zenith angle. One possible advantage of the polarimetric technique is that the Ring effect detections can be made without recourse to solar measurements directly or indirectly using an attenuator. Finally, a model without knowledge of the filling-in mechanism, has yielded a good qualitative agreement with the observational behaviours and it can be taken as a first step to explain the variation of the linear polarization across the spectral line.

Diurnal variation of the linear polarization across the H? and H? Fraunhofer lines of the terrestrial atmosphere, and a detection of a ?daylight flash?, II

In Paper I, the ability of using the polarimetric technique to observe the filling-in of the Fraunhofer spectrum line profiles—the Ring effect—has been presented (using the Hβ Fraunhofer line only). It has also been found that the added light, which caused the filling-in, is polarized. Here, a description is given of some observations, which, hopefully, will lead to a better understanding of the Ring effect using the Hα and Hβ Fraunhofer spectral lines. The observations of the filling-in effect at the zenith have covered many conditions which might be considered as controlling its behaviour at these two spectral regions. The data reveal variations of polarization at the centres of those Fraunhofer lines as a function of solar zenith angle. The results show no uniformity for the added light intensity, its value was depending on the kind of day (clear and turbid) and/or on the solar zenith angle. Also the photometric observational studies reported here suggest that a new phenomenon behaving like airglow has been discovered. It is referred to here as a ‘daylight flash’ and was recorded (for short periods) on three days at both the Hα and Hβ Fraunhofer lines with different strengths. The cores of these lines were filled in while the near continua were unaffected.

An investigation of lunar luminescence by spectropolarimetry

The Fraunhofer line filling-in effect associated with lunar spectra has been investigated by spectropolarimetry. From considerations that the effect is attributable to luminescence, simple calculations suggest that changes of the order of 0.001 in the degree of polarization, p, are anticipated in the spectral line relative to its nearby continua. Observations have been made of several lunar areas at H α and H β with spectral resolution ∼2 Å and with polarimetric uncertainties in p ∼ ±0.0002 ( i. e., 2/100 of 1%). In general, the measurements reveal no significant changes of p between the core of the lines and their nearby continua. For the few data sets considered as displaying marginal changes, no consistent pattern of behavior emerges between them. Although the measurements neither confirm not negate the filling-in effect, they clearly indicate that any luminescence at these wavelengths cannot be unpolarized. For the Hα measurements, one lunar region displayed an anomalous polarization position angle, θ, relative to the local scattering plane with the core of the line being less affected than the continuum. Other observed lunar regions suggest that a rotation of θ ∼ 0°.25 occurs within the linear core. No explanation is immediately available for this phenomenon although it may be related to Rayleigh-Broullin scattering. A similar effect was not observed in Hβ.

Polarization measurements of the ring effect in the daytime sky

Previous measurements of the filling-in of Fraunhofer lines in the spectrum of the daytime sky or Ring effect have suggested that this added component to the general Rayleigh scattered light is unpolarized. There is a consensus in the literature that this is the case. However, measurements of the Hβ line from the zenith sky are reported here which reveal that the Ring component is substantially polarized (~ 25%) particularly at some times of the day. The degree of polarization at these times is substantially higher than is predicted by rotational Raman scattering from air molecules, this mechanism being favoured as the origin of the Ring intensity. These results suggest that some alternative or additional mechanism for producing the line filling-in effect needs to be invoked.