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The first year of the grant was spent in setting up the laboratory, and in starting research on a number of different projects. All are concerned with the visual processing of information in the perception of objects. A series of experiments has explored the perception of conjunctions of features, attempting to determine what makes this difficult or easy. A new method (detection of apparent motion) was tested and a modification of feature-integration theory was developed to accommodate the new results. Other projects have been concerned with coding of features, finding evidence for modularity, testing the level of abstraction at which features (such as orientation) are coded, the different media which support the coding of shape, and the space in which they are represented (retinal or three-dimensional). Another project has probed the effects of perceptual learning with extended practice at detecting particular sets of targets; the results suggest that automatization in search is highly specific to the practiced task and has little effect on other perceptual tests. Six graduate students are at present, working on projects wholly or partly supported by the grant.

It is suggested that recent advances in the construction of artificial vision systems provide the beginnings of a framework for an information processing analysis of human visual perception. A review is made of some pertinent investigations which have appeared in the psychological literature, along with some of the salient and potentially useful theoretical concepts which have resulted from the attempts to build computer vision systems. An attempt is made to integrate these two sources of ideas to suggest some desirable structural and behavioral concepts which apply to both the natural and the artificial systems.

It is suggested that recent advances in the construction of artificial vision systems provide the beginnings of a framework for an information processing analysis of human visual perception. A review is made of some pertinent investigations which have appeared in the psychological literature, along with some of the salient and potentially useful theoretical concepts which have resulted from the attempts to build computer vision systems. An attempt is made to integrate these two sources of ideas to suggest some desirable structural and behavioral concepts which apply to both the natural and the artificial systems.

It is suggested that recent advances in the construction of artificial vision systems provide the beginnings of a framework for an information processing analysis of human visual perception. A review is made of some pertinent investigations which have appeared in the psychological literature, along with some of the salient and potentially useful theoretical concepts which have resulted from the attempts to build computer vision systems. An attempt is made to integrate these two sources of ideas to suggest some desirable structural and behavioral concepts which apply to both the natural and the artificial systems.

Functional organization of visual fields

Reported were four experiments which investigated the developmental and mental retardation aspects of an initial stage of visual information processing termed iconic memory. The stage was explained to involve processing visual stimuli prior to sensation and through to recognition. In three of the four experiments, the paradigm of visual masking was used to determine the speed or efficiency of information processing; the Crawford-pattern mask technique was used throughout. The four experiments were titled age effects on backward visual masking, adult age effects on backward visual masking, forward and backward masking with normal and retarded subjects, and iconic storage and information availability by normal and retarded subjects, respectively. Subjects in the four experiments ranged in age from 5 to 55 years of age. Major findings of the experiments were reported to be development and documentation of a methodology surmounting previous problems in studying development and mental retardation aspects of iconic memory, establishment of relationship between age variable and efficiency with which visual information is processed, and poorer performance by retarded subjects on iconic memory tasks than by normal subjects matched in terms of mental age. (CB)

The research we have done has shown that effective saccadic control is achieved by a division of labor between high-level mechanisms that select targets and plan scanning strategies, and low-level mechanisms that bring the line of sight to the center of attended regions and adjust saccade metrics by means of adaptive control. Understanding these processing and programming tricks is valuable for designing tasks and displays that produce best-possible performance, for developing models of the human visual, motor and cognitive systems, and for improving the design of robotic and other systems that, like human beings, must acquire information sequentially from large and complex visual scenes, with only a limited processing resources.

This final progress report summaries the main recent results; full reports of the results are contained in the papers appended herewith. The summary also reviews some results from previous AFOSR grants where these are necessary to provide the background for the current research. Four areas are summarized: (1) Basic Mechanisms of Visual Motion and Texture Perception; (2) Lateral Interations in Texture Stimuli; (3) Information Processing; and (4) Visual Attention and Short-Term Memory.

The visual detection of a concealed target involves the interaction of object characteristics and observer-related variables. This report briefly summarises object characteristics which may affect detectability, and then concentrates upon observer variables. Some of the physical limitations of the human optical system are mentioned. An information processing theory is reviewed and adopted as a model upon which some hypotheses are based. In the case of a search of a large, complex field, automatic processing of information may lead to the selection of likely target areas, however controlled search processes may be required to scan the information in an automatically selected array.

The visual detection of a concealed target involves the interaction of object characteristics and observer-related variables. This report briefly summarises object characteristics which may affect detectability, and then concentrates upon observer variables. Some of the physical limitations of the human optical system are mentioned. An information processing theory is reviewed and adopted as a model upon which some hypotheses are based. In the case of a search of a large, complex field, automatic processing of information may lead to the selection of likely target areas, however controlled search processes may be required to scan the information in an automatically selected array.

Eight autistic children and young adolescents (mean age 12.9 years) were compared to normal chronological age controls. Ss were required to discriminate briefly presented visual stimuli when they were preceded or followed by a visual noise mask and when they were not. The minimum stimulus exposure duration for criterion identification of unmasked letters, the critical stimulus duration, was determined first. Subsequently, Ss were required to identify the letters under conditions of forward and backward masking. Autistic Ss showed a slight deficiency in relation to equal chronological age normals in their ability to discriminate unmasked letters. When this deficiency was controlled for, however, they did not differ from the controls in the visual masking experiment. Results provided support for the notion of a discontinuity between the disorders of autism, mental retardation, and schizophrenia. (Author)

Eight autistic children and young adolescents (mean age 12.9 years) were compared to normal chronological age controls. Ss were required to discriminate briefly presented visual stimuli when they were preceded or followed by a visual noise mask and when they were not. The minimum stimulus exposure duration for criterion identification of unmasked letters, the critical stimulus duration, was determined first. Subsequently, Ss were required to identify the letters under conditions of forward and backward masking. Autistic Ss showed a slight deficiency in relation to equal chronological age normals in their ability to discriminate unmasked letters. When this deficiency was controlled for, however, they did not differ from the controls in the visual masking experiment. Results provided support for the notion of a discontinuity between the disorders of autism, mental retardation, and schizophrenia. (Author)

Eight autistic children and young adolescents (mean age 12.9 years) were compared to normal chronological age controls. Ss were required to discriminate briefly presented visual stimuli when they were preceded or followed by a visual noise mask and when they were not. The minimum stimulus exposure duration for criterion identification of unmasked letters, the critical stimulus duration, was determined first. Subsequently, Ss were required to identify the letters under conditions of forward and backward masking. Autistic Ss showed a slight deficiency in relation to equal chronological age normals in their ability to discriminate unmasked letters. When this deficiency was controlled for, however, they did not differ from the controls in the visual masking experiment. Results provided support for the notion of a discontinuity between the disorders of autism, mental retardation, and schizophrenia. (Author)

Eight autistic children and young adolescents (mean age 12.9 years) were compared to normal chronological age controls. Ss were required to discriminate briefly presented visual stimuli when they were preceded or followed by a visual noise mask and when they were not. The minimum stimulus exposure duration for criterion identification of unmasked letters, the critical stimulus duration, was determined first. Subsequently, Ss were required to identify the letters under conditions of forward and backward masking. Autistic Ss showed a slight deficiency in relation to equal chronological age normals in their ability to discriminate unmasked letters. When this deficiency was controlled for, however, they did not differ from the controls in the visual masking experiment. Results provided support for the notion of a discontinuity between the disorders of autism, mental retardation, and schizophrenia. (Author)

This report used a combination of physiological and anatomical approaches to elucidate the functional organization of visual cortex in the macaque monkey. One project was a single cell analysis of texture vision, using texture patterns of the type developed by Julesz for human psychophysical studies. Many cells tested in area V2 responded to static or moving texture gradients in ways which were not predictable on the basis of responses to individual texture elements and which correlated with the preattentive discriminability of these texture patterns to human observers. A second project involved the development of a computerized technique for generating two-dimensional maps of cerebral cortex. An algorithm based on simulated annealing procedures was used to construct a complete map of primary visual cortex, thereby demonstrating its suitability for dealing with anatomical data from highly convoluted regions of cortex. A third project involved the use of voltage-sensitive dyes to monitor activity patterns in visual cortex. This technique offers great promise for analyzing the organization of large neural ensembles with high spatial and temporal resolution. Keywords: Cerebral cortex; Pattern recognition; Cortical mapping; Single neuron physiology.

This study uses the 7.5% carbon dioxide model of anxiety induction to investigate the effects of state anxiety on visual and auditory information processing. Participants will undergo two inhalations (of 7.5% CO2-enriched air and medical air) and complete two tasks that present clear and degraded visual and auditory stimuli. We hypothesise that 7.5% CO2 inhalation will be associated with impaired performance and this effect will be greatest when stimuli are degraded.

This study uses the 7.5% carbon dioxide model of anxiety induction to investigate the effects of state anxiety on visual and auditory information processing. Participants will undergo two inhalations (of 7.5% CO2-enriched air and medical air) and complete two tasks that present clear and degraded visual and auditory stimuli. We hypothesise that 7.5% CO2 inhalation will be associated with impaired performance and this effect will be greatest when stimuli are degraded.

One of a series of investigations on the Project on an Information Memory Model, the purpose of this study was to determine the amount and kind of visual information processed and stored in the memory of children using different modalities of observation. Children, aged 5, 9 and 13 years, were randomly assigned to one of three treatment groups. Two of the treatment groups individually viewed silently (N=21 per age level) or vocally (N=21 per age level) a projected 35mm slide of a living room. The third group (N-45 per age level) viewed the picture display in groups of three and verbally exchanged enumerations of items. Five minutes were allowed for viewing the slide. The subjects then verbally recalled the viewing experience and their recollections were tape recorded. As the age of the subjects increased, the numbe of picture item messages and variety or number of different picture items verbalized in the enumeration phase of the experiment also increased. A message processor algorithm for forecasting cognitions of verbal and nonverbal modalities was used with a prediction error of less than two percent. An item dimension algorithm for forecasting cognitions was developed to measure the M unit structure of memory pathways. The finding was that chronological age was related to M units of variations of learning and recall tasks. (Author/PEB)

One of a series of investigations on the Project on an Information Memory Model, the purpose of this study was to determine the amount and kind of visual information processed and stored in the memory of children using different modalities of observation. Children, aged 5, 9 and 13 years, were randomly assigned to one of three treatment groups. Two of the treatment groups individually viewed silently (N=21 per age level) or vocally (N=21 per age level) a projected 35mm slide of a living room. The third group (N-45 per age level) viewed the picture display in groups of three and verbally exchanged enumerations of items. Five minutes were allowed for viewing the slide. The subjects then verbally recalled the viewing experience and their recollections were tape recorded. As the age of the subjects increased, the numbe of picture item messages and variety or number of different picture items verbalized in the enumeration phase of the experiment also increased. A message processor algorithm for forecasting cognitions of verbal and nonverbal modalities was used with a prediction error of less than two percent. An item dimension algorithm for forecasting cognitions was developed to measure the M unit structure of memory pathways. The finding was that chronological age was related to M units of variations of learning and recall tasks. (Author/PEB)

This project concerned the discovery and description of basic mechanisms of human visual motion and texture perception. Motion and texture are critical inputs to visual perception. Basic mechanisms of motion are of particular interest because they are perhaps the primary substrate for perceptual recovery of 3D depth structures and orientation in space, they are critical for detecting new objects and events in the environment, as well as playing an important role in 2D perception. Motion and texture are considered together here because the problem of discriminating velocity in a one- dimensional motion stimulus is formally equivalent to the problem of discriminating orientation in a texture stimulus: the t dimension of the motion stimulus becomes the y dimension of the texture stimulus.

This publication is a compilation of the papers presented at the NASA conference on Visual Information Processing for Television and Telerobotics. The conference was held at the Williamsburg Hilton, Williamsburg, Virginia on May 10 to 12, 1989. The conference was sponsored jointly by NASA Offices of Aeronautics and Space Technology (OAST) and Space Science and Applications (OSSA) and the NASA Langley Research Center. The presentations were grouped into three sessions: Image Gathering, Coding, and Advanced Concepts; Systems; and Technologies. The program was organized to provide a forum in which researchers from industry, universities, and government could be brought together to discuss the state of knowledge in image gathering, coding, and processing methods.

This publication is a compilation of the papers presented at the NASA conference on Visual Information Processing for Television and Telerobotics. The conference was held at the Williamsburg Hilton, Williamsburg, Virginia on May 10 to 12, 1989. The conference was sponsored jointly by NASA Offices of Aeronautics and Space Technology (OAST) and Space Science and Applications (OSSA) and the NASA Langley Research Center. The presentations were grouped into three sessions: Image Gathering, Coding, and Advanced Concepts; Systems; and Technologies. The program was organized to provide a forum in which researchers from industry, universities, and government could be brought together to discuss the state of knowledge in image gathering, coding, and processing methods.

Tri 1 – 2018/2019

This study aims to explore wherther and how tasting actual drinks would affect visual information processing.

Tri 1 2019/2020

Food information has a high reward value for human beings, and may be more so for those who are overweight or obese. Stimuli with high reward value may be particularly conspicuous, demanding our attention even when we are attending to something else. Yet, the nature and neural signals of potential biased processing of food information remains unclear. Moreover, despite decades of research, a reliable measure of food information processing remains elusive, making it a methodological bottleneck in obesity and disordered eating research. To address the nature of biased attention processing, we ask 1) how attention is biased toward two cardinal properties of food information, namely, healthfulness and tastiness, even though the food information is irrelevant to the task at hand; and 2) whether and how such processing might be dependent on the demandingness of the central task (i.e., perceptual load). In our previous study which has been preregistered, we recruited 32 participants and measured their responses to infrequent visual food information embedded in streams of other visual objects in EEG, specifically, by using a variant of steady-state visual evoked potential (SSVEP), oddball fast periodic visual stimulation (FPVS). The infrequent food objects (i.e., oddballs) are one of four different combinations in different trials based on healthfulness and tastiness: 1) high healthfulness and high tastiness; 1) high healthfulness and low tastiness; 3) low healthfulness and high tastiness; and 4) low healthfulness and low tastiness. The perceptual load of the central task is either low (detection of a certain color of letters) or high (detection of certain combinations of color and identity of letters). In this study, the results demonstrated robust and reliable implicit categorization of food information at the individual level for all 32 participants, with the effect not modulated by perceptual load or tastiness (but might be by healthfulness). Since oddball FPVS is a novel paradigm applied to studying food information processing, it would be critical to replicate the findings in order to develop FPVS as a reliable measure of food information processing as well as apply this tool to obesity or other clinical sample with eating disorders. In particular, the modulating effect of healthfulness observed was not salient and requires further evidence. Furthermore, the lack of modulation by tastiness and perceptual load also warrants replication. Therefore, we plan to conduct a replication study with the same paradigm and sample size to validate our previous findings.

Researchers are concerned with the end-to-end performance of image gathering, coding, and processing. The applications range from high-resolution television to vision-based robotics, wherever the resolution, efficiency and robustness of visual information acquisition and processing are critical. For the presentation at this workshop, it is convenient to divide research activities into the following two overlapping areas: The first is the development of focal-plane processing techniques and technology to effectively combine image gathering with coding, with an emphasis on low-level vision processing akin to the retinal processing in human vision. The approach includes the familiar Laplacian pyramid, the new intensity-dependent spatial summation, and parallel sensing/processing networks. Three-dimensional image gathering is attained by combining laser ranging with sensor-array imaging. The second is the rigorous extension of information theory and optimal filtering to visual information acquisition and processing. The goal is to provide a comprehensive methodology for quantitatively assessing the end-to-end performance of image gathering, coding, and processing.

Researchers are concerned with the end-to-end performance of image gathering, coding, and processing. The applications range from high-resolution television to vision-based robotics, wherever the resolution, efficiency and robustness of visual information acquisition and processing are critical. For the presentation at this workshop, it is convenient to divide research activities into the following two overlapping areas: The first is the development of focal-plane processing techniques and technology to effectively combine image gathering with coding, with an emphasis on low-level vision processing akin to the retinal processing in human vision. The approach includes the familiar Laplacian pyramid, the new intensity-dependent spatial summation, and parallel sensing/processing networks. Three-dimensional image gathering is attained by combining laser ranging with sensor-array imaging. The second is the rigorous extension of information theory and optimal filtering to visual information acquisition and processing. The goal is to provide a comprehensive methodology for quantitatively assessing the end-to-end performance of image gathering, coding, and processing.

Researchers are concerned with the end-to-end performance of image gathering, coding, and processing. The applications range from high-resolution television to vision-based robotics, wherever the resolution, efficiency and robustness of visual information acquisition and processing are critical. For the presentation at this workshop, it is convenient to divide research activities into the following two overlapping areas: The first is the development of focal-plane processing techniques and technology to effectively combine image gathering with coding, with an emphasis on low-level vision processing akin to the retinal processing in human vision. The approach includes the familiar Laplacian pyramid, the new intensity-dependent spatial summation, and parallel sensing/processing networks. Three-dimensional image gathering is attained by combining laser ranging with sensor-array imaging. The second is the rigorous extension of information theory and optimal filtering to visual information acquisition and processing. The goal is to provide a comprehensive methodology for quantitatively assessing the end-to-end performance of image gathering, coding, and processing.

This project examined the effects menstruation may have on visual attention in women. A recent study examined electroencephalographic (EEG) gender differences using a visual object recognition task. Results indicated certain EEG amplitudes (specifically, P300 and N400) are greater in women than men. This study extended the previous findings to determine if these increased EEG amplitudes vary across menstrual phases. Eighteen female participants participated in a series of 3 EEG recording sessions using the same visual object recognition task from the previous study; 18 male participants completed this task once. Analyses from 15 of the 18 female and 16 of the 18 male participants support the previous finding of larger P300 amplitudes in response to relevant stimuli for women compared with men. While there was no distinctive N400 component in this study, there was a late negative (LN) component which was found to vary significantly between men and women. In addition, multiple visual evoked potential (VEP) components varied significantly across the menstrual cycle. In particular, the N200 component appeared to provide greater differences between menstrual phases than either the p300 or LN components; however, the results varied greatly by head location, The differentiation found with VEP components in response to the pop-out task used in this study provide support for basic visual processing variation across the menstrual cycle and between genders.

Limitations in the ability to temporarily represent information in visual working memory (VWM) are crucial for (visual) cognition. Whether VWM processing is dependent on an object’s saliency (i.e., how much it stands out) has been neglected in VWM research. Therefore, we developed a novel VWM task design that allows direct control over saliency. In three experiments with this task (on 10, 31, and 60 healthy adults, respectively), we consistently find that VWM performance is strongly and parametrically influenced by saliency and that both an object’s relative (to concurrently presented objects) and absolute saliency influence VWM processing. We also demonstrate that this effect is indeed due to bottom-up saliency, rather than differential fit between each object and the top-down attentional set. A simple computational model assuming that VWM performance is determined by the weighted sum of absolute and relative saliency accounts well for the observed data patterns.

Differential levels of automaticity for processing information from tachistoscopic displays were studied using three variations of the partial report procedure. Processing of both spatial and identity information in letter displays was assessed simultaneously and then independently. Analyses indicated feature extraction is a highly automated process while spatial information extraction is a controlled process. Implications for separate processing pathways in the visual system are discussed

Includes bibliographies

Memory and Cognition : v.9, no.3, 1981, p. 301-307

Visual processing of televised information was compared among 85 Japanese and 111 American boys and girls at the kindergarten and 4th-grade levels. The literatures on cognition and learning indicate that language and child rearing factors are more conducive to the development of iconic processing skills in Japanese children than in American children, a phenomenon which increases with age. The reverse pattern is found for verbal processing skills. It was predicted that after viewing a television program without narration or dialogue, Japanese children's amount and concentration of visual attention and comprehension would be higher than that of American children, particularly at the 4th-grade level. Results confirmed the predictions for visual attention, suggesting that different television processing strategies were employed. Contrary to the predictions, American children scored higher than Japanese children on the comprehension test, perhaps because of the cultural differences in expectations about the testing procedure. The results are discussed in the context of processing differences. Alternative explanations for the findings are explored, and directions for future research are suggested. Appended are seven pages of references, seven tables and two figures. (Author/RH)

Visual processing of televised information was compared among 85 Japanese and 111 American boys and girls at the kindergarten and 4th-grade levels. The literatures on cognition and learning indicate that language and child rearing factors are more conducive to the development of iconic processing skills in Japanese children than in American children, a phenomenon which increases with age. The reverse pattern is found for verbal processing skills. It was predicted that after viewing a television program without narration or dialogue, Japanese children's amount and concentration of visual attention and comprehension would be higher than that of American children, particularly at the 4th-grade level. Results confirmed the predictions for visual attention, suggesting that different television processing strategies were employed. Contrary to the predictions, American children scored higher than Japanese children on the comprehension test, perhaps because of the cultural differences in expectations about the testing procedure. The results are discussed in the context of processing differences. Alternative explanations for the findings are explored, and directions for future research are suggested. Appended are seven pages of references, seven tables and two figures. (Author/RH)

The research completed over the last twelve months has included a number of studies concerned with evoked cortical potential correlates of visual stimulus processing in humans. The first experiment was conducted in order to replicate an earlier finding in which the amplitude of a relatively late positive component of the event related potential (ERP), known as the P3, was larger to a line orientation that required a 'yes' response than one that required a 'no'. The angular difference between the two lines was only 5 degrees. Another purpose was to assess the reliability of the better right hemisphere performance found with male subjects in the line orientation discrimination task used. In a second experiment, we examined the possibility of hemispheric asymmetry in response to two different colors (red and blue). The two hemispheres responded in essentially the same manner to the two colors. However, an interesting finding was the larger ERPs of both left and right hemispheres to the color blue, especially with central visual field stimulation. A third experiment was directed at the determination of whether the right hemisphere would be more sensitive to visual masking than the left, especially with a metacontrast paradigm which is dependent on spatial factors to produce the masking effect. A fourth experiment was performed to determine the relative responsivity of the two hemispheres to verbal (letter) and spatial (geometric form) stimuli.

The research sought to understand certain fundamental aspect of visual information processing in the areas of recognition, exploration and search behavior-progress was made in the following areas. Laboratory Reconfiguration. During the six months of this contract ASL undertook to upgrade and augment the eye movement recording equipment at HEL. One major effort was devoted to writing a data acquisition program to record and analyze pupil diameter data. Data Collection & Analysis. An entirely new hardware and software data acquisition environment had to be designed and built and a new I/O configuration designed for the PDP 11 computer. Keywords: Computer applications; Modeling; Optical imaging; Algorithms; Attention; Vision; Pattern recognition; Target recognition; Data storage; Laboratory equipment.

This final progress report summaries the results of a study that successfully determined the functional architecture of visual motion perception, in the sense of defining the mechanisms involved and the relations between them. It was proved that visual motion is computed by two neural systems: primitive motion-energy extraction (e.g., Reichardt detector) and higher-level feature tracking. A psychophysical pedestal paradigm was used to exclude the feature- tracking process and thereby to obtain pure measures of motion-energy extraction. Motion energy extraction was found to be exclusively monocular, fast (cutoff frequency is 12 Hz) and sensitive (can utilize 0.2% contrast), 'bottom- up', and, to operate on both luminance (first-order) and contrast (second-order) motion stimuli. Motion feature tracking was found to operate interocularly as well as monocularly, have a cutoff frequency of 3 Hz, and to be both bottom up (it computes motion from luminance, contrast, depth, motion-motion, flicker and other type of stimuli) and top-down (e.g., attentional states influence what appears to move). The full report is appended.

Eye movements determine the location and velocity of the retinal image. Thus, to understand how we see it is necessary to understand both how eye movements are controlled and how they effect visual information processing. The proposed research is concerned with both problems. Specifically: the effect of expectations on smooth eye movements; and the eye moves smoothly in the direction of expected future target motion. Experiments will determine how expectations and guesses about the direction of future motion are formulated and the relative contributions of expectations and retinal image motion to smooth eye movements. The effect of saccades and saccade-like stimulus perturbations on visual information processing: Saccades continually displace the retinal image, yet we see the world as a single coherent picture. Experiments will find out whether the visual system selectively tolerates rapid lateral displacements, or whether the decision to move the eye is required. Programming sequences of saccades: Experiments will show whether sequences of saccades can be pre-programmed, and whether use of such sequences improves performance of visual tasks.

In the domain of motion perception, the implementation of a new pedestal paradigm and some critical subsidiary paradigms (interocular displays, stimulus superpositions with varying phases and directions, alternating-feature stimuli, and attentional manipulations) enabled the measurement in isolation of the spatial and temporal characteristics of the three main human motion perception mechanisms (the so-called first-, second, and third-order systems). The first- and second-order systems, known previously, were now shown to exist in duplicate, having a primarily left eye and a primarily right eye computational branch. Additionally, a purely binocular (third-order) motion mechanism was discovered and measured.

Food information has a high reward value for human beings, and may be more so for those who are overweight or obese. Stimuli with high reward value may be particularly conspicuous, demanding our attention even when we are attending to something else. Yet, the nature and neural signals of potential biased processing of food information remains unclear. To address the nature of biased attention processing, we ask 1) how attention is biased toward two cardinal properties of food information, namely, healthiness and tastiness, even though the food information is irrelevant to the task at hand; and 2) whether and how such processing might be dependent on the demandingness of the central task (i.e., perceptual load). We measure EEG responses to infrequent visual food information embedded in streams of other visual objects, specifically, by using oddball fast periodic visual stimulation (FPVS), which is a variant of steady-state visual evoked potentials (SSVEP). The infrequent food objects are of four different combinations based on healthiness and tastiness: 1) high healthiness and high tastiness; 1) high healthiness and low tastiness; 3) low healthiness and high tastiness; and 4) low healthiness and low tastiness. The perceptual load of the central task is either low (detection of a certain color of letters) or high (detection of certain combinations of color and identity of letters). To evaluate the potential role of satiety, we measure FPVS responses to food oddballs in two different states: at least 4 hours after the previous meal; and within 1 hour of the last meal. Subjective satiety level is recorded prior to the experiment. We then ask how such biased processing might be linked to individual differences in: 1) external eating (measured by Dutch Eating Behavior Questionnaire, DEBQ); 2) impulsivity (measured by Barratt Impulsiveness Scale, BIS-11); 3) trait reward sensitivity (measured by the BIS/BAS scale); 4) BMI. Test–retest reliability will be assessed for the EEG FPVS task.

Food information has a high reward value for human beings, and may be more so for those who are overweight or obese. Stimuli with high reward value may be particularly conspicuous, demanding our attention even when we are attending to something else. Yet, the nature and neural signals of potential biased processing of food information remains unclear. To address the nature of biased attention processing, we ask 1) how attention is biased toward two cardinal properties of food information, namely, healthiness and tastiness, even though the food information is irrelevant to the task at hand; and 2) whether and how such processing might be dependent on the demandingness of the central task (i.e., perceptual load). We measure EEG responses to infrequent visual food information embedded in streams of other visual objects, specifically, by using oddball fast periodic visual stimulation (FPVS), which is a variant of steady-state visual evoked potentials (SSVEP). The infrequent food objects are of four different combinations based on healthiness and tastiness: 1) high healthiness and high tastiness; 1) high healthiness and low tastiness; 3) low healthiness and high tastiness; and 4) low healthiness and low tastiness. The perceptual load of the central task is either low (detection of a certain color of letters) or high (detection of certain combinations of color and identity of letters). To evaluate the potential role of satiety, we measure FPVS responses to food oddballs in two different states: at least 4 hours after the previous meal; and within 1 hour of the last meal. Subjective satiety level is recorded prior to the experiment. We then ask how such biased processing might be linked to individual differences in: 1) external eating (measured by Dutch Eating Behavior Questionnaire, DEBQ); 2) impulsivity (measured by Barratt Impulsiveness Scale, BIS-11); 3) trait reward sensitivity (measured by the BIS/BAS scale); 4) BMI. Test–retest reliability will be assessed for the EEG FPVS task.

The publications describe progress in two related areas of visual information processing: motion processing and visual attention. The full equivalence between Reichart motion detection and Fourier motion analysis (first-order motion processing) was proved formally. A new experimental paradigm was developed to test the model of nonFourier (2nd-order) motion processing. This model, which accounts for the perception of motion-from-texture, consists of a stage of linear spatio-temporal filtering followed by fullwave rectification and then by standard (Reichart) motion analysis. It was demonstrated that human 2nd-order motion is, for practical purposes, one-dimensional (i.e., a single channel system). The spatial filter that this channel utilizes was measured and found to be lowpass. Work on attentional processes in visual task using rapid sequences of superimposed patterns showed that highly trained subjects were unable to use gross physical differences to filter out unattended items at an early stage of perceptual processing. On the contrary, the results are explained by postulating that attended and unattended elements of the input are tagged as such at an early-stage, and are then discriminated later on the of this tag. (Author)

Research on several interrelated topics is described in this report. These projects are focused on the analysis of feature and conjunction detection, models of selective attention, and curve tracing. One project examines the effects of a heterogeneous background on feature search. Another assesses spatial factors (such a target-distractor separation) in the detection of targets defined in terms of simple features. A third project has the goal of developing methods for determining the extent to which processing is serial or parallel. A fourth represents initial efforts to determine whether conjoined features are represented in retinotopic or spatiotopic 'maps'. A fifth explores top-down and bottom-up factors in visual search. A sixth makes use of an inhibitory priming method to test early-and late-selection models of selective attention. Finally, a project is reported in which the operation of visual curve tracing is studied. Keywords: Visual perception; Attention; Perception; Information processing; Vision; Visual search; Curve tracing.

Eye movements determine the location and velocity of the retinal image. Thus, to understand how we see it is necessary to understand both how eye movements are controlled and how they affect visual information processing. The proposed research is concerned with both problems, specifically: (1) the effect of expectations on smooth eye movements; (2) the effect of saccades and saccade-like stimulus perturbations on visual information processing; and (3) programming sequences of saccades.

This article is from Frontiers in Human Neuroscience , volume 7 . Abstract Objective: Mismatch negativity (MMN) and P3 are unique ERP components that provide objective indices of human cognitive functions such as short-term memory and prediction. Bipolar disorder (BD) is an endogenous psychiatric disorder characterized by extreme shifts in mood, energy, and ability to function socially. BD patients usually show cognitive dysfunction, and the goal of this study was to access their altered visual information processing via visual MMN (vMMN) and P3 using windmill pattern stimuli.Methods: Twenty patients with BD and 20 healthy controls matched for age, gender, and handedness participated in this study. Subjects were seated in front of a monitor and listened to a story via earphones. Two types of windmill patterns (standard and deviant) and white circle (target) stimuli were randomly presented on the monitor. All stimuli were presented in random order at 200-ms durations with an 800-ms inter-stimulus interval. Stimuli were presented at 80% (standard), 10% (deviant), and 10% (target) probabilities. The participants were instructed to attend to the story and press a button as soon as possible when the target stimuli were presented. Event-related potentials (ERPs) were recorded throughout the experiment using 128-channel EEG equipment. vMMN was obtained by subtracting standard from deviant stimuli responses, and P3 was evoked from the target stimulus.Results: Mean reaction times for target stimuli in the BD group were significantly higher than those in the control group. Additionally, mean vMMN-amplitudes and peak P3-amplitudes were significantly lower in the BD group than in controls.Conclusions: Abnormal vMMN and P3 in patients indicate a deficit of visual information processing in BD, which is consistent with their increased reaction time to visual target stimuli.Significance: Both bottom-up and top-down visual information processing are likely altered in BD.

Report of a 3 year investigation into the physiological structure of the mantis shrimp eye. This creature has the most advanced and most complex eye of any creature in nature, with many band-pass elements, including those outside of human viewing spectra. It also can see polarized light linear and circular, both directions

In a visual recognition masking experiment, a target stimulus to be identified is either preceded or followed by a second stimulus called a masking stimulus. The experiments described here provide estimates of both developmental and aging differences in visual backward masking under conditions which maximize interference in the central visual system. The results indicate that when no-mask recognition performance is at 100 percent, significant Age X Stimulus Onset Asynchronies interactions can be detected. However, the absence of this type of interaction when no-mask recognition performance is adjusted to the 70 percent level suggests that these interactions are caused by factors other than rate of processing differences. (Author/BW)

This article is from Frontiers in Psychology , volume 5 . Abstract When dissimilar stimuli are presented to the two eyes, only one stimulus dominates at a time while the other stimulus is invisible due to interocular suppression. When both stimuli are equally potent in competing for awareness, perception alternates spontaneously between the two stimuli, a phenomenon called binocular rivalry. However, when one stimulus is much stronger, e.g., due to higher contrast, the weaker stimulus can be suppressed for prolonged periods of time. A technique that has recently become very popular for the investigation of unconscious visual processing is continuous flash suppression (CFS): High-contrast dynamic patterns shown to one eye can render a low-contrast stimulus shown to the other eye invisible for up to minutes. Studies using CFS have produced new insights but also controversies regarding the types of visual information that can be processed unconsciously as well as the neural sites and the relevance of such unconscious processing. Here, we review the current state of knowledge in regard to neural processing of interocularly suppressed information. Focusing on recent neuroimaging findings, we discuss whether and to what degree such suppressed visual information is processed at early and more advanced levels of the visual processing hierarchy. We review controversial findings related to the influence of attention on early visual processing under interocular suppression, the putative differential roles of dorsal and ventral areas in unconscious object processing, and evidence suggesting privileged unconscious processing of emotional and other socially relevant information. On a more general note, we discuss methodological and conceptual issues, from practical issues of how unawareness of a stimulus is assessed to the overarching question of what constitutes an adequate operational definition of unawareness. Finally, we propose approaches for future research to resolve current controversies in this exciting research area.