Laborious Object Recognition Dallenbach, K. M. (1951). A puzzle-picture with a new principle of concealment. American Journal of Psychology, 64, 181-191. Gray, C. M., Koenig, P., Engel, A. K., & Singer, W. (1989). Oscillatory responses in cat visual cortex exhibit inter-columnar synchronization which reflects global stimulus properties. Nature, 338, 334-337. Hebb, D. O. (1949). The organization of behavior. Wiley. Hubel, D. H., & Wiesel (1968). Receptive fields and functional architecture of monkey striate cortex. Journal of Physiology, 195, 215-243. Hummel, J. E., & Biederman, I. (1992). Dynamic binding in a neural network for shape recognition, Psychological Review, 99, 480-517. Kolers, P. A., & Roediger, H. L. (1984). Procedures of Mind. Journal of Verbal Learning and Verbal Behavior, 23, 425-449. Kreiter, A. K., & Singer, W. (1996). Stimulus-dependent sychronization of neuronal responses in the visual cortex of awake macaque monkey. Journal of Neuroscience, 16, 2381-2396. Logothetis NK, Pauls J, Poggio T. 1995. Shape representation in the inferior temporal cortex of monkeys. Curr. Biol, 5:552-63 McClelland, J. L., & Rumelhart, D.E. (1981). An interactive activation model of context effects in letter perception: Part 1. An account of basic findings. Psychological Review, 88, 375-407. Moran, J., & Desimone, R. (1985). Selective attention gates visual processing in the extrastriate cortex. Science, 229, 782-784. Perrett, D. I., Smith, P. A. J., Potter, D. D., Mistlin, A. J., Head, A. D., Jeeves, M. A. (1984). Neurones responsive to faces in the temporal cortex: Studies of functional organization, sensitivity to identity and relation to perception. Human Neurobiology., 3, 197-208 Rodriguez, E., George, N., Lachaux, J-P, Martinerie, J., Renault, B., & Varela, F. J. (1999). Perception's shadow: Long-distance synchronization of human brain activity. Nature, 397, 403-433. Rzempoluck, E. J. (1998). EEG changes index camoflaged object identification: A pilot study, Biological Psychology, 47, 181-191. Singer, W. (1995). Development and plasticity of cortical processing architectures, Science, 270, 758-764. Tovee, M. J., Rolls, E. T., & Ramachandran, V. S. (1996). Rapid visual learning in neurones of the primate temporal visual cortex. Neuroreport, 7, 2757-2760. Yu, K., & Blake, R. (1992). Do recognizable figures enjoy an advantage in binocular rivalry. Journal of Experimental Psychology: Human Perception and Performance, 4, 1158-1173. Dolan, R. J., Fink, G. R., Rolls, E., Booth, M., Holmes, A., Frackowiak, R. S. J., & Friston, K. J. (1997). How the brain learns to see objects and faces in an impoverished context. Nature, 389, 596-599. Perception is commonly delineated into "bottom-up" and "top-down" processes. Bottomup processes are those that begin with low-level perceptual features derived from a stimulus, and compose them together into larger and larger units until a coherent perceptual interpretation of an entire scene is constructed. Via top-down processes, an oberserver's expectations, knowledge, and experience influence how the individual elements of a scene are interpreted. These two types of processes are not mutually exclusive, and there are formal models that provide an account of how top-down and bottom-up processing can each have a simultaneous influence on the other (McClelland & Rumelhart, 1981). Typically, expectations and stimulus information will mutually determine the perceptual interpretation given to an object. Still, one striking phenomenon that demonstrates a contribution of experience-driven expectations to object perception is the subjective difference between perceiving a degraded image of an object before and after the true interpretation of the object has been revealed. As originally described by Dallenbach (1951), when observers are shown degraded images such as Figure X, they frequently cannot determine the object being represented, even though the object comprises the major part of the image and is depicted in a canonical perspective. When the object is pointed out to an observer, the observer frequently has an "Aha" reaction in which the degraded image is readily interpreted. Once interpreted, it is difficult for the observer to return to their naive state of seeing the image as a set of unorganized blotches. This phenomenon suggests a powerful role of experience-driven expectations because the physical information contained in a degraded image is the same before and after its interpretation has been revealed (pre- and postrevelation). The subjective difference in perception of the degraded image comes from perceptual learning that requires only a single presentation of the original, undegraded image. The subjectively different perceptual experiences associated with pre- and post-revelation degraded images are reliably associated with differences in brain activity. Magnetic Resonance Imagery (MRI) has revealed that post-revelation images produce higher activity in parietal and inferior temporal regions than do pre-revelation images (Dolan et al, 1997). The inferior temporal area is known to be associated with object recognition (Moran & Desimone, 1985), particularly for the recognition of familiar objects (Logothetis, Pauls, & Poggio, 1995). This MRI evidence is consistent with single-cell recordings of neurons in the inferior temporal region of macaque monkeys. Degraded face images produced higher neuron firing rates when they were presented after the original , undegraded face images were revealed than before revelation (Tovee, Rolls, & Ramachadran, 1996). Finally, there is evidence from eletroencephalogram (EEG) recordings in humans that one of the brain difference between images that are coherently interpreted and those that are not is that the former causes more synchronized neural activity in at 34-40 HZ (in the Gamma frequency range). Rodriguez et. al. (1999) showed their participants degraded images of faces, and separately analyzed those trials where participants did and did not perceive faces. Participants who interpreted upright degraded faces as depicting faces showed greater synchronized neural activity between left parietooccipital and frontotemporal regions at 250 milliseconds after the onset of the stimulus than did participants who did not interpret inverted degraded faces as depicting faces. These explorations of neural activity suggest two accounts for what occurs when an image is given a meaningful interpretation. First, detectors in a particular region may signal the interpretation of an object. Such an account is consistent with work suggesting the existence of neurons that are selectively activated not only by simple stimulus features such as lines moving at particular orientation, but also of by complex stimulus configurations such as hands or faces (Hubel & Wiesel, 1968). The specicity of cells in the inferotemporal regions is at least partially learned given that it is especially pronounced for familiar faces (Perrett et al., 1984). Second, a coherent interpretation of an image may be the result of binding together neural activity caused by parts of the image that come from the same object. By this account, coherent objects are represented by dynamically forming assemblies of neurons (Hebb, 1949). One of the main candidates for "labeling" neural activity that is to be bound together is by synchronizing the electrical discharges between neurons within an assembly (Gray et al, 1989; Singer, 1995). The strength of response synchronization between neurons reflects perceptual constraints such as the Gestalt laws of organization, including continuity, proximity, similarity, colinearity, and common fate (Kreiter & Singer, 1996; Singer, 1995). However, given the results of Rodriguez et al., top-down interpretability, as well as bottom-up stimulus properties, may determine the synchronization of neural activity. One advantage of representing objects by the synchronized neural activity rather than the firing rate of individual neurons is that a complex scene can be decomposed into several objects, with the neurons responding to different parts firing with different phases (Hummel & Biederman, 1992). Ascending from neural-level considerations to a behavioral analysis, there are four revealing properties associated with changing the subjective perception of a degraded image by previously revealing its original form. First, once revealed, the correct interpretation of a degraded image persists even if the image is presented only after delay (see our Experiment X). Pilot work in our laboratory suggests that even after delays of two months, there is a strong influence of revelation on degraded image interpretation. Second, once the degraded image has been revealed, it is hard to look at the degraded image and not interpret it, or to give it an alternative interpretation. Although alternative interpretations are frequent pre-revelation, they seem to be inhibited by the propert interpretation. Third, providing an interpretation of an image by verbally presenting its category (e.g. saying "look for a cow") is much less effective in changing subjective organization than is either showing the original version of the image, or a simplified drawing of it (Dallenbach, 1951). Fourth, presenting the original version of an image facilitates interpretation of the degraded image much more if they are presented at roughly the same time (see our Experiment X). The original picture is much more effective if it actively used to interpret the degraded picture, rather than simply being a passive prime. Together, these properties suggest that exposure to an original picture acts to prime the procedure of segmenting an image into objects and background. A hallmark of a strong "aha" effect (i.e. large difference between pre- and post-revelation subjective experience) is that figure-ground segmentation cues in the image conflict with the actual segmentations required to correctly interpret the object. For example, in Figure X.... . Simultaneous exposure to an original and degraded image allows people to tune their figure-ground segmentation processes to create the correct segmentation of the degraded picture. By stressing procedural priming, rather than semantic, strategic, or episodic priming, we are claiming that the large difference between pre- and post-revelation perception of degraded images stems from altering the segmentation routines that take relatively unprocessed inputs and produce structured figure/ground organizations. Open questions: when/how early? Is pathway "greased" just like it is when an object becomes familiar? That is, is a post-revealed object just like an object that has been presented many times before? Yu and Blake - show some people what the dalmatian really is a picture of - revelation. Results: dog predominates more even if it is not revealed. Information about structural configuration is registered early. object superiority effect Pomerantz et al. Weisstein, N., & Harris, C. S. (1974). visual detection of line segments: An object-superiority effect. Science, 186, 752-755. Degraded object perception as a model of agnosia. Like agnosics, people can see the degraded object fine, and could reconstruct it quite well. They just can't combine the parts together to create a coherent interpretation- exactly what apperceptive agnosics complain of. ACCESSION NUMBER 1996-09110-003 DOCUMENT TYPE Journal-Article TITLE Identification of fragmented pictures under ascending versus fixed presentation in young and elderly adults: Evidence for the inhibition-deficit hypothesis. AUTHOR Lindfield,-Kimberly-C.; Wingfield,-Arthur; Bowles,-Nancy-L. SOURCE Aging-and-Cognition.1994 Dec; Vol 1(4): 282-291. ISSN0928-9917 PUBLICATION YEAR 1994 ABSTRACT Hypothesized that (1) older adults have deficient inhibitory processes and (2) poorer performance in ascending than in fixed presentations of fragmented stimuli is due to residual activation interference. 24 6086 yr old volunteers and 24 17-22 yr old college students were tested for the ability to identify degraded pictures that were presented using either an ascending (AC) or a fixed (FC) condition. In the AC, Ss identified the pictures at each level of increasing completeness until correct identification was achieved. In the FC, Ss identified degraded pictures that were presented once at an intermediate level of visual completeness. An ANOVA confirmed that accuracy was higher in the FC than the AC, and that the main effect of age was not significant. When Ss were equated on a pretest for performance on the AC, a marginal trend was found for the elderly Ss only. Additional evidence for reduced inhibitory processes in older Ss was seen in the Ss' correct response latencies. Results are interpreted as support for the inhibition-deficit hypothesis. ((c) 1997 APA/PsycINFO, all rights reserved) . TITLE Perceptual/sensory information versus performance level as indicators of competitive activation in an object identification task: Evidence from aging. AUTHOR Lindfield,-Kimberly-C.; Wingfield,-Arthur SOURCE Brain-and-Cognition.1998 Jun; Vol 37(1): 24-27. ISSN0278-2626 PUBLICATION YEAR 1998 ABSTRACT Young and elderly adults were tested for the ability to identify degraded pictures presented either in a series of incremental steps with each step increasing the completeness of the visual information (ascending condition) or in one single exposure (fixed condition). The probability of correct identification in the fixed condition was better than the ascending condition once the amount of visual information shown reached a certain level of completeness. This was the case for both age groups tested even though the performance of older adults was lower than young adults. Findings are consistent with the competitive activation model of perceptual interference in picture identification (C. R. Luo and J. G. Snodgrass, 1994). ((c) 1998 APA/PsycINFO, all rights reserved) . Cortical dynamics of three-dimensional figure-ground perception of two-dimensional pictures. AUTHOR Grossberg,-Stephen SOURCE Psychological-Review.1997 Jul; Vol 104(3): 618-658. ISSN0033-295X PUBLICATION YEAR 1997 ABSTRACT Develops the FACADE theory of 3-dimensional (3-D) vision and figure-ground separation to explain data concerning how 2-dimensional pictures give rise to 3-D percepts of occluding and occluded objects, and how geometrical and contrastive properties of a picture cooperate or compete when forming the boundaries and surface representations that subserve conscious percepts. Spatially long-range cooperation and spatially short-range competition work together to separate the boundaries of occluding figures from their occluded neighbors, and this process is sensitive to image T junctions at which occluded figures contact occluding figures. These boundaries control the filling-in of color within multiple depth-sensitive surface representations. Feedback between surface and boundary representations strengthens consistent boundaries while inhibiting inconsistent ones. Both the boundary and the surface representations of occluded objects may be amodally completed, while the surface representations of unoccluded objects become visible through modal completion. Functional roles for conscious modal and amodal representations in object recognition, spatial attention, and reaching behaviors are discussed. Model interactions are interpreted in terms of visual, temporal, and parietal cortices. ((c) 1997 APA/PsycINFO, all rights reserved) . Do recognizable figures enjoy an advantage in binocular rivalry? AUTHOR Yu,-Karen; Blake,-Randolph SOURCE Journal-of-Experimental-Psychology:-Human-Perception-and-Performance.1992 Nov; Vol 18(4): 1158-1173. ISSN0096-1523 PUBLICATION YEAR 1992 ABSTRACT Five experiments examined whether recognizable stimuli predominate in binocular rivalry. It was found that a face predominated more than did a pattern equated for spatial frequency, luminance, and contrast; an objective reaction time (RT) procedure confirmed predominance of the face. The face was still liable to fragmentation as stimulus size increased. Observers tracked exclusive dominance of a picture of a camouflaged figure (a Dalmatian dog) prior to and then following discovery of the figure's presence; control observers received the same protocol with a scrambled version of the dog stimulus. Compared with control results, predominance of the dog picture was higher even before observers knew of the camouflaged figure. Inversion of the dog figure reduced its predominance. Binocular rivalry is sensitive to object-related, configural properties of a stimulus. ((c) 1997 APA/PsycINFO, all rights reserved) . Recognition of computer-generated pictures on monochrome monitors. AUTHOR Baker,-Patti-R.; Belland,-John-C.; Cambre,-Marjorie-A. SOURCE Journal-of-Computer-Based-Instruction.1985 Fal; Vol 12(4): 104-107. ISSN0098-597X PUBLICATION YEAR 1985 ABSTRACT Examined whether 64 2nd-4th graders could recognize computer-generated pictures on monochrome monitors. Ss were randomly assigned to 1 of 2 conditions. Ss in the 1st treatment were asked to identify on a monochrome monitor a figure that was initially presented in its original form and then as a redesigned, more distinguishable figure. The redesigned figure had greater figure^ground contrast because color substitutions were made that used pixel patterns to provide contrast in the monochromatic display. The order of picture presentation was reversed for Ss in the 2nd treatment. Ss also completed the Children's Embedded Figures Test to assess their field independence^dependence. Results indicate that regardless of grade or field independence^dependence characteristics, Ss were unable to discern critical features of a color graphic displayed on a monochromatic monitor unless it was designed to enhance figure^ground separation. Implications for the design of instructional software that incorporates microcomputer-generated graphics are discussed. (14 ref) ((c) 1997 APA/PsycINFO, all rights reserved) . Evoked potential correlates of figure and ground. AUTHOR Landis,-Theodor; Lehmann,-D.; Mita,-T.; Skrandies,-W. SOURCE International-Journal-of-Psychophysiology.1984 Jun; Vol 1(4): 345-348. ISSN0167-8760 PUBLICATION YEAR 1984 ABSTRACT Brain potentials averaged during the viewing of an alternating positive and negative "hidden man" puzzle picture were averaged from 8 Ss before and after they learned to recognize the figure. After vs before recognition, there was significantly more evoked positivity at 64/96 msec latency and more negativity at 224/256 msec and 352-480 msec latency over parietal areas during the viewing of the positive picture (recognizable as a face). It is hypothesized that separate physiological changes might reflect learned meaningfulness of the figure (which entails increased attention) and figure extraction from ground. (10 ref) ((c) 1997 APA/PsycINFO, all rights reserved) . Is visual image segmentation a bottom-up or an interactive process? AUTHOR Vecera,-Shaun-P.; Farah,-Martha-J. SOURCE Perception-and-Psychophysics.1997 Nov; Vol 59(8): 1280-1296. ISSN0031-5117 PUBLICATION YEAR 1997 ABSTRACT Visual image segmentation is the process by which the visual system groups features that are part of a single shape. In Exps 1 and 2, Ss were presented with two overlapping shapes and were asked to determine whether two probed locations were on the same shape or on different shapes. The availability of top-down support was manipulated by presenting either upright or rotated letters. Ss were fastest to respond when the shapes corresponded to familiar shapes--the upright letters. In Exp 3, a variant of this segmentation task was used to rule out the possibility that Ss performed same/different judgments after segmentation and recognition of both letters. Exp 4 ruled out the possibility that the advantage for upright letters was merely due to faster recognition of upright letters relative to rotated letters. Results suggest that the previous effects were not due to faster recognition of upright letters; stimulus familiarity influenced segmentation. The results are discussed in terms of an interactive model of visual image segmentation. ((c) 1998 APA/PsycINFO, all rights reserved) . TITLE Hidden figures are ever present. AUTHOR Mens,-Lucas-H.; Leeuwenberg,-Emanuel-L. SOURCE Journal-of-Experimental-Psychology:-Human-Perception-and-Performance.1988 Nov; Vol 14(4): 561-571. ISSN0096-1523 PUBLICATION YEAR 1988 ABSTRACT Preference judgments about alternative interpretations of unambiguous patterns can be explained in terms of a rivalry between a preferred and a second-best interpretation (cf. Leeuwenberg & Buffart, 1983). We tested whether this second-best interpretation corresponds to a suppressed but concurrently present interpretation or whether it merely reflects an alternative view that happens to be preferred less often. Two patterns were present immediately following each other with a very short onset asynchrony: a complete pattern and one out of three possible subpatterns of it, corresponding to the best, the second best, or an odd interpretation of the complete pattern. Subjects indicated which subpattern was presented by choosing among the three subpatterns shown after each trial. The scores, corrected for response-bias effects, indicated a relative facilitation of the second-best interpretation, in agreement with its predicted "hidden" presence. This result is more in line with theories that capitalize on the quality of the finally selected representation than with processing models aimed at reaching one single solution as fast and as economically as possible. ((c) 1997 APA/PsycINFO, all rights reserved) . Spatial context in recognition. AUTHOR Bar,-Moshe; Ullman,-Shimon SOURCE Perception.1996; Vol 25(3): 343-352. ISSN0301-0066 PUBLICATION YEAR 1996 ABSTRACT Exps 1 and 2, with 18 graduate students, investigated the role of individual objects in recognition of complete figures and the influence of contextual information on identification of ambiguous objects. Configurations of objects that were placed in either proper or improper spatial relations were used, and response times and error rates in a recognition task were measured. Proper spatial relations among the objects of a scene decreased response times and error rates in the recognition of individual objects. Also, the presence of objects that had a unique interpretation improved the identification of ambiguous objects in the scene. Ambiguous objects were recognized faster and with fewer errors in the presence of clearly recognized objects compared with the same objects in isolation or in improper spatial relations. Implications for the organization of recognition memory are discussed. ((c) 1997 APA/PsycINFO, all rights reserved) . TITLE Visual schemas in neural networks for object recognition and scene analysis. AUTHOR Leow,-Wee-Kheng; Miikkulainen,-Risto SOURCE Connection-Science:-Journal-of-Neural-Computing,-Artificial-Intelligence-andCognitive-Research.1997 Jun; Vol 9(2): 161-200. ISSN0954-0091 PUBLICATION YEAR 1997 ABSTRACT VISOR is a large connectionist system that shows how visual schemas can be learned, represented and used through mechanisms natural to neural networks. Processing in VISOR is based on cooperation, competition, and parallel bottom-up and top-down activation of schema representations. VISOR is robust against noise and variations in the inputs and parameters. It can indicate the confidence of its analysis, pay attention to important minor differences, and use context to recognize ambiguous objects. Experiments also suggest that the representation and learning are stable, and behavior is consistent with human processes such as priming, perceptual reversal and circular reaction in learning. The schema mechanisms of VISOR can serve as a starting point for building robust high-level vision systems, and perhaps for schema-based motor control and natural language processing systems as well. ((c) 1997 APA/PsycINFO, all rights reserved)(journal abstract) . TITLE Object recognition based on impulse restoration with use of the expectationmaximization algorithm. AUTHOR Abu-Naser,-Ahmad; Galatsanos,-Nikolas-P.; Wernick,-Miles-N.; Schonfeld,-Dan SOURCE Journal-of-the-Optical-Society-of-America.-A.1998 Sep; Vol 15(9): 2327-2340. ISSN0740-3232 PUBLICATION YEAR 1998 ABSTRACT It has recently been demonstrated that object recognition can be formulated as an image-restoration problem. In this approach, which the authors term impulse restoration, the objective is to restore a delta function that indicates the detected object's location. Solutions based on impulse restoration for the Gaussian-noise case are developed, and a new iterative approach, based on the expectation-maximization (EM) algorithm, that simultaneously estimates the background statistics and restores a delta function at the location of the template, is proposed. A Monte Carlo study and localization-receiver-operating-characteristics curves was used to evaluate the performance of this approach quantitatively and compare it with existing methods. Experimental results that demonstrate that impulse restoration is a powerful approach for detecting known objects in images severely degraded by noise are presented. ((c) 1998 APA/PsycINFO, all rights reserved) KEY PHRASE TITLE How the brain learns to see objects and faces in an impoverished context. AUTHOR Dolan,-R.-J.; Fink,-G.-R.; Rolls,-E.; Booth,-M.; Holmes,-A.; Frackowiak,-R.-S.-J.; Friston,-K.-J. SOURCE Nature.1997 Oct; Vol 389(6651): 596-599. ISSN0028-0836 PUBLICATION YEAR 1997 ABSTRACT A degraded image of an object or face, which appears meaningless when seen for the first time, is easily recognizable after viewing an undegraded version of the same image. The neural mechanisms by which this form of rapid perceptual learning facilitates perception are not well understood. Psychological theory suggests the involvement of systems for processing stimulus attributes, spatial attention and feature binding, as well as those involved in visual imagery. Here it is investigated where and how this rapid perceptual learning is expressed in the human brain by using functional neuroimaging to measure brain activity during exposure to degraded images before and after exposure to the corresponding undegraded versions. Perceptual learning of faces or objects enhanced the activity of inferior temporal regions known to be involved in face and object recognition respectively. A strong coupling was observed between the temporal face area and the medial parietal cortex when faces were perceived. This suggests that perceptual learning involves direct interactions between areas involved in face recognition and those involved in spatial attention, feature binding and memory recall. ((c) 1998 APA/PsycINFO, all rights reserved) KEY PHRASE An optimal estimation approach to visual perception and learning. AUTHOR Rao,-Rajesh-P.-N. SOURCE Vision-Research.1999 Jun; Vol 39(11): 1963-1989. ISSN0042-6989 PUBLICATION YEAR 1999 ABSTRACT How does the visual system learn an internal model of the external environment? How is this internal model used during visual perception? How are occlusions and background clutter so effortlessly discounted for when recognizing a familiar object? How is a particular object of interest attended to and recognized in the presence of other objects in the field of view? In this paper, the author attempts to address these questions from the perspective of Bayesian optimal estimation theory. Using the concept of generative models and the statistical theory of Kalman filtering, it is shown how static and dynamic events occurring in the visual environment may be learned and recognized given only the input images. The author also describes an extension of the Kalman filter model that can handle multiple objects in the field of view. The resulting robust Kalman filter model demonstrates how certain forms of attention can be viewed as an emergent property of the interaction between top-down expectations and bottom-up signals. Experimental results are provided to help demonstrate the ability of such a model to perform robust segmentation and recognition of objects and image sequences in the presence of occlusions and clutter. ((c) 1999 APA/PsycINFO, all rights reserved) Figure-ground organization and object recognition processes: An interactive account. AUTHOR Vecera,-Shaun-P.; O'Reilly,-Randall-C. SOURCE Journal-of-Experimental-Psychology:-Human-Perception-and-Performance.1998 Apr; Vol 24(2): 441-462. ISSN0096-1523 PUBLICATION YEAR 1998 ABSTRACT Traditional bottom-up models of visual processing assume that figure-ground organization precedes object recognition. This assumption seems logically necessary: How can object recognition occur before a region is labeled as figure? However, some behavioral studies find that familiar regions are more likely to be labeled figure than less familiar regions, a problematic finding for bottom-up models. An interactive account is proposed in which figure-ground processes receive top-down input from object representations in a hierarchical system. A graded, interactive computational model is presented that accounts for behavioral results in which familiarity effects are found. The interactive model offers an alternative conception of visual processing to bottom-up models. ((c) 1998 APA/PsycINFO, all rights reserved)(journal abstract) Leow,-Wee-Kheng; Miikkulainen,-Risto SOURCE Connection-Science:-Journal-of-Neural-Computing,-Artificial-Intelligence-andCognitive-Research.1997 Jun; Vol 9(2): 161-200. ISSN0954-0091 PUBLICATION YEAR 1997 ABSTRACT VISOR is a large connectionist system that shows how visual schemas can be learned, represented and used through mechanisms natural to neural networks. Processing in VISOR is based on cooperation, competition, and parallel bottom-up and top-down activation of schema representations. VISOR is robust against noise and variations in the inputs and parameters. It can indicate the confidence of its analysis, pay attention to important minor differences, and use context to recognize ambiguous objects. Experiments also suggest that the representation and learning are stable, and behavior is consistent with human processes such as priming, perceptual reversal and circular reaction in learning. The schema mechanisms of VISOR can serve as a starting point for building robust high-level vision systems, and perhaps for schema-based motor control and natural language processing systems as well. ((c) 1997 APA/PsycINFO, all rights reserved)(journal abstract) Visual perception. AUTHOR Paap,-Kenneth-R.; Partridge,-Derek BOOK SOURCE McTear, Michael F.; et-al. (1988). Understanding cognitive science. Ellis Horwood series in cognitive science. (pp. 69-101). Chichester, England UK: Ellis Horwood, Ltd; New York, NY, USA: Halsted Press. 264 pp.SEE BOOK ISBN0745801617 (hardcover, Ellis Horwood); 047021175X (hardcover, Halsted) PUBLICATION YEAR 1988 ABSTRACT (from the chapter) top-down effects and the modularity of mind /// object recognition by basically bottom-up processing /// lessons from natural vision / pragmatism leads to oversight and hallucination / attentional control /// bringing top-down information into play / the activation-verification model of word recognition /// lessons from neurophysiology: natural and artificial edge detection /// connectionist models ((c) 1997 APA/PsycINFO, all rights reserved) Perception and knowledge. AUTHOR Rock,-Irvin SOURCE Acta-Psychologica.1985 May; Vol 59(1): 3-22. ISSN0001-6918 PUBLICATION YEAR 1985 ABSTRACT Argues that knowledge concerning the object, scene, or event in a conscious propositional form generally does not affect perception, while knowledge in the form of stored representations of past visual or phylogenetic experience can affect perception. Exceptions to the 1st generalization can occur if the stimulus is ambiguous and can support a cued or suggested interpretation or one in line with what is known to be present as well as it can support the perception that occurs spontaneously. Knowledge in the form of stored representations can affect perception in various ways: It enables recognition and interpretation to occur; it enables perceptual discrimination among similar members of a category to occur; it can lead to perceptual enrichment effects; it provides internal solutions that can be accessed in cases in which perceptual problem solving occurs; it provides rules or laws concerning geometrical optics on the basis of which phenomena such as perceptual constancy and the like can be achieved; and it can lead to the recalibration of tactual or visual sensation. However, before such top-down effects of past experience can occur, bottom-up processes must achieve a preliminary perception. That perception provides the bridge to the relevant stored representations accessed on the basis of similarity. (38 ref) ((c) 1997 APA/PsycINFO, all rights reserved) Bottom-up connectionist models of 'interaction' AUTHOR Norris,-Dennis BOOK SOURCE Altmann, Gerry T. M. (Ed); Shillcock, Richard (Ed); et-al. (1993). Cognitive models of speech processing: The Second Sperlonga Meeting. (pp. 211-234). Hove, England UK: Lawrence Erlbaum Associates, Inc., Publishers. xiv, 531 pp.SEE BOOK ISBN0863773028 (hardcover) PUBLICATION YEAR 1993 ABSTRACT (from the book) Presents an exploration of some of the properties of simple connectionist models of word recognition, including a model of lexical access. Some of the properties of these models are demonstrated as part of a discussion of claims for 'top-down' activation in psychological models, notably the word superiority effect, and J. Elman and J. McClelland's (1988) demonstration of phoneme restoration in conjunction with the compensation for coarticulation effect. /// It is demonstrated that it is possible to obtain apparent top-down behaviour from a connectionist model that contains only feedforward and delay connections. These simulations force attention to the issues of levels of description and processing, and demonstrate that traditional box-and-arrow models may not trivially be transformed into connectionist models without a careful reappraisal of how the learning process effectively redistributes their functional architecture. They also demonstrate the difficulty of determining the precise generalizations that are acquired by even small connectionist networks. ((c) 1998 APA/PsycINFO, all rights reserved) Does lexical information influence the perceptual restoration of phonemes? AUTHOR Samuel,-Arthur-G. SOURCE Journal-of-Experimental-Psychology:-General.1996 Mar; Vol 125(1): 28-51. ISSN0096-3445 PUBLICATION YEAR 1996 ABSTRACT A critical issue in modeling speech perception is whether lexical representations can affect lower level (e.g., phonemic) processing. Phonemic restoration studies have provided support for such top-down effects, but there have also been a number of failures to find them. A methodology is introduced that provides good approximations to the underlying distributions of perceived intactness that are assumed in signal detection analyses of restoration. This methodology provides a sensitive means to determine the necessary conditions for lexical feedback to occur. When these conditions are created, a reliable lexical influence on phonemic perception results. The experiments thus show that lexical activation does influence lower level processing, and that these influences are fragile. The theoretical implications of real but fragile lexical effects are discussed. ((c) 1997 APA/PsycINFO, all rights reserved)(journal abstract)