Visual Feature Integration Research Articles

Feature binding across different visual dimensions

The human brain represents different kinds of visual feature dimensions in different ways. For example, surface features exhibit some properties that are very different from contour features, and some feature dimensions may be represented more extensively in either the dorsal or the ventral visual stream. Given such differences, we investigated feature binding across different feature dimensions and whether some feature dimensions might be more easily bound together than others. In Experiment 1, we looked at cross-dimension bindings for all combinations of color, orientation, and shape dimensions, while at the same time controlling for feature discriminability. Rates of correct binding, illusory conjunctions, and feature errors were equivalent in all cases. There was no bias so that some feature dimensions were easier to combine than others. In Experiment 2, we manipulated the difficulty of feature discrimination for the key, target-defining feature and the report feature. Rates of binding errors increased with difficulty of the key feature, but not with that of the report feature. The accuracy of feature discrimination could be dissociated from the accuracy of binding the feature to an object. Across both experiments, the accuracy of feature binding was independent of specific feature dimensions or perceptibility. These findings are discussed in relation to both feature integration and multiple-stage accounts of visual feature integration.

Beyond colour perception: Auditory–visual synaesthesia induces experiences of geometric objects in specific locations

Our brain constantly integrates signals across different senses. Auditory–visual synaesthesia is an unusual form of cross-modal integration in which sounds evoke involuntary visual experiences. Previous research primarily focuses on synaesthetic colour, but little is known about non-colour synaesthetic visual features. Here we studied a group of synaesthetes for whom sounds elicit consistent visual experiences of coloured ‘geometric objects’ located at specific spatial location. Changes in auditory pitch alter the brightness, size, and spatial height of synaesthetic experiences in a systematic manner resembling the cross-modal correspondences of non-synaesthetes, implying synaesthesia may recruit cognitive/neural mechanisms for ‘normal’ cross-modal processes. To objectively assess the impact of synaesthetic objects on behaviour, we devised a multi-feature cross-modal synaesthetic congruency paradigm and asked participants to perform speeded colour or shape discrimination. We found irrelevant sounds influenced performance, as quantified by congruency effects, demonstrating that synaesthetes were not able to suppress their synaesthetic experiences even when these were irrelevant for the task. Furthermore, we found some evidence for task-specific effects consistent with feature-based attention acting on the constituent features of synaesthetic objects: synaesthetic colours appeared to have a stronger impact on performance than synaesthetic shapes when synaesthetes attended to colour, and vice versa when they attended to shape. We provide the first objective evidence that visual synaesthetic experience can involve multiple features forming object-like percepts and suggest that each feature can be selected by attention despite it being internally generated. These findings suggest theories of the brain mechanisms of synaesthesia need to incorporate a broader neural network underpinning multiple visual features, perceptual knowledge, and feature integration, rather than solely focussing on colour-sensitive areas.

Visual Feature Integration Indicated by pHase-Locked Frontal-Parietal EEG Signals

The capacity to integrate multiple sources of information is a prerequisite for complex cognitive ability, such as finding a target uniquely identifiable by the conjunction of two or more features. Recent studies identified greater frontal-parietal synchrony during conjunctive than non-conjunctive (feature) search. Whether this difference also reflects greater information integration, rather than just differences in cognitive strategy (e.g., top-down versus bottom-up control of attention), or task difficulty is uncertain. Here, we examine the first possibility by parametrically varying the number of integrated sources from one to three and measuring phase-locking values (PLV) of frontal-parietal EEG electrode signals, as indicators of synchrony. Linear regressions, under hierarchical false-discovery rate control, indicated significant positive slopes for number of sources on PLV in the 30–38 Hz, 175–250 ms post-stimulus frequency-time band for pairs in the sagittal plane (i.e., F3-P3, Fz-Pz, F4-P4), after equating conditions for behavioural performance (to exclude effects due to task difficulty). No such effects were observed for pairs in the transverse plane (i.e., F3-F4, C3-C4, P3-P4). These results provide support for the idea that anterior-posterior phase-locking in the lower gamma-band mediates integration of visual information. They also provide a potential window into cognitive development, seen as developing the capacity to integrate more sources of information.

Robust multiple-vehicle tracking via adaptive integration of multiple visual features

Abstract This article presents a robust approach to tracking multiple vehicles with integration of multiple visual features. The observation is modeled by democratic integration strategies according to the reliability of the information in the current multi-visual features to adjust their weights. The appearance model is also embedded in a particle filter (PF) tracking framework. Furthermore, we propose a new model updating algorithm based on the PF. In order to avoid incorrect results caused by "model drift" introduced into the observation model, model updating should only be controlled in a reliable manner, and the rate of updating is based on reliability. This article also presents the experiments using a real video sequence to verify the proposed method.

Cholinergic enhancement reduces orientation-specific surround suppression but not visual crowding

Acetylcholine (ACh) reduces the spatial spread of excitatory fMRI responses in early visual cortex and receptive field size of V1 neurons. We investigated the perceptual consequences of these physiological effects of ACh with surround suppression and crowding, two phenomena that involve spatial interactions between visual field locations. Surround suppression refers to the reduction in perceived stimulus contrast by a high-contrast surround stimulus. For grating stimuli, surround suppression is selective for the relative orientations of the center and surround, suggesting that it results from inhibitory interactions in early visual cortex. Crowding refers to impaired identification of a peripheral stimulus in the presence of flankers and is thought to result from excessive integration of visual features. We increased synaptic ACh levels by administering the cholinesterase inhibitor donepezil to healthy human subjects in a placebo-controlled, double-blind design. In Experiment 1, we measured surround suppression of a central grating using a contrast discrimination task with three conditions: (1) surround grating with the same orientation as the center (parallel), (2) surround orthogonal to the center, or (3) no surround. Contrast discrimination thresholds were higher in the parallel than in the orthogonal condition, demonstrating orientation-specific surround suppression (OSSS). Cholinergic enhancement decreased thresholds only in the parallel condition, thereby reducing OSSS. In Experiment 2, subjects performed a crowding task in which they reported the identity of a peripheral letter flanked by letters on either side. We measured the critical spacing between the targets and flanking letters that allowed reliable identification. Cholinergic enhancement with donepezil had no effect on critical spacing. Our findings suggest that ACh reduces spatial interactions in tasks involving segmentation of visual field locations but that these effects may be limited to early visual cortical processing.

Now you see it, now you don’t: Design dependent sound symbolism effect in categorization studies

A number of studies have demonstrated sound-symbolism effects in adults and in children. Moreover, recently, ERP studies have shown that the sensitivity to sound-symbolic label–object associations occurs within 200 ms of object presentation (Kovic et al., 2010). It was argued that this effect may reflect a more general process of auditory–visual feature integration where properties of auditory stimuli facilitate a mapping to specific visual features. Here we demonstrate that the sound-symbolism effect is design dependent, namely — it occurs only when mapping from auditory to visual stimuli and not vice verse. Two groups of participants were recruited for solving the categorization task. They were presented them with 12 visual stimuli, half of which were rounded and another half of angular shapes. One group was trained to classify the rounded objects as ‘takete’ and the rounded ones as ‘maluma’, whereas the other group mapped ‘takete’ to rounded and ‘maluma’ to angular shapes. Moreover, half of these two groups heard the label before seeing the objects, whereas the other half was given the label after perceiving the object. The results revealed the sound-symbolism effect only in the group which was trained on the auditory–visual objects mapping and not in the one trained on the visual–auditory mappings. Thus, despite the previous findings we demonstrate that the sound-symbolism effect is not significant per se, but design-dependent and we argue that the sound brings up a mental image that is more constrained than the sounds brought up by a picture.

The Function and Fallibility of Visual Feature Integration: A Dynamic Neural Field Model of Illusory Conjunctions

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Feature Processing and Illusory Conjunctions in Infants' Long-Term Memory

Theories of visual information processing and feature integration, along with previous infant research, have indicated that only individual object features, and not the feature relations, are perceptually processed by early visual mechanisms. Previous research from within the memory domain has further suggested that, based on the encoding of features, errors in memory in the form of illusory conjunctions (i.e. miscombination of features from disparate objects) are likely. Considering that research has shown that infants' memory is particularly reliant on features, their recognition mechanisms should be quite susceptible to memory conjunction errors. Using the mobile-conjugate reinforcement paradigm, young infants were trained with mobiles displaying both O's and R's (or P's and Q's) and tested with stimuli that contained a miscombination of those features such as a Q (or an R), or a stimulus that did not contain these features (S). Results revealed that infants miscombined the individual features of the O and R (and P and Q) such that they recognized a Q (and R). Infants discriminated, however, the S mobile. These findings support previous research and the notion that object features encoded in infant long-term memory are likely stored as independent units irrespective of the spatial relations among those features, consequently allowing for the miscombination of features upon retrieval. Interestingly, however, infants discriminated a mobile displaying the same features as in the R but in a different spatial combination, suggesting that infants encoded some spatial characteristic of the individual feature. In sum, the present findings suggest that individual object features, and not the spatial feature relations, have a preferential status in young infants' long-term memory.

Feature integration in visual working memory: parietal gamma activity is related to cognitive coordination

The mechanism by which distinct subprocesses in the brain are coordinated is a central conundrum of systems neuroscience. The parietal lobe is thought to play a key role in visual feature integration, and oscillatory activity in the gamma frequency range has been associated with perception of coherent objects and other tasks requiring neural coordination. Here, we examined the neural correlates of integrating mental representations in working memory and hypothesized that parietal gamma activity would be related to the success of cognitive coordination. Working memory is a classic example of a cognitive operation that requires the coordinated processing of different types of information and the contribution of multiple cognitive domains. Using magnetoencephalography (MEG), we report parietal activity in the high gamma (80–100 Hz) range during manipulation of visual and spatial information (colors and angles) in working memory. This parietal gamma activity was significantly higher during manipulation of visual-spatial conjunctions compared with single features. Furthermore, gamma activity correlated with successful performance during the conjunction task but not during the component tasks. Cortical gamma activity in parietal cortex may therefore play a role in cognitive coordination.

Brain Activity Patterns Uniquely Supporting Visual Feature Integration after Traumatic Brain Injury

Traumatic brain injury (TBI) patients typically respond more slowly and with more variability than controls during tasks of attention requiring speeded reaction time. These behavioral changes are attributable, at least in part, to diffuse axonal injury (DAI), which affects integrated processing in distributed systems. Here we use a multivariate method sensitive to distributed neural activity to compare brain activity patterns of patients with chronic phase moderate to-severe TBI to those of controls during performance on a visual feature integration task assessing complex attentional processes that has previously shown sensitivity to TBI. The TBI patients were carefully screened to be free of large focal lesions that can affect performance and brain activation independently of DAI. The task required subjects to hold either one or three features of a Target in mind while suppressing responses to distracting information. In controls, the multi-feature condition activated a distributed network including limbic, prefrontal, and medial temporal structures. TBI patients engaged this same network in the single-feature and baseline conditions. In multi-feature presentations, TBI patients alone activated additional frontal, parietal, and occipital regions. These results are consistent with neuroimaging studies using tasks assessing different cognitive domains, where increased spread of brain activity changes was associated with TBI. Our results also extend previous findings that brain activity for relatively moderate task demands in TBI patients is similar to that associated with of high task demands in controls.

Entraining the brain? Effects of rhythmic brain stimulation protocols on oscillatory brain activity and behaviour

Event Abstract Back to Event Entraining the brain? Effects of rhythmic brain stimulation protocols on oscillatory brain activity and behaviour Gregor Thut1* and Vincenzo Romei2 1 University of Glasgow, United Kingdom 2 University College London, United Kingdom Brain oscillations in distinct frequency bands have been related to specific brain functions, such as sleep slow-waves to memory consolidation, posterior alpha-activity in wake participants to sensory input regulation and gamma-activity to visual feature integration, among other cognitive activities. However, with these relations revealed using mainly electroencephalography (EEG) and magnetoencephalography (MEG), the nature of these links remains unknown (whether only correlative, or causal instead). Based on new findings and protocols for transcranial brain stimulation, this symposium explores whether brain oscillations can be entrained by rhythmic stimulation protocols to thereby bias performance in desired directions. This would favour a causal relation between brain oscillations and functions, and likely prove highly beneficial for the study of human brain rhythms. By entrainment of brain rhythms, specific hypothesis on the nature of the link between various brain oscillations and aspects of perception and performance could be tested. By controlling brain oscillations in specific patient groups, the contributions of these oscillations to disease or rehabilitation could be probed. The talks of this symposium cover rhythmic stimulation protocols, such as (i) rhythmic bursts of transcranial magnetic stimulation (rTMS), (ii) transcranial alternating current stimulation (tACS), (iii) transcranial direct current stimulation (tDCS), (iv) transcranial electric stimulation (TES) and (v) optogenetics. Using concurrent EEG recordings in humans and intra- and extracellular recordings in animals, the talks provide initial, supportive evidence for entrainment through rhythmic stimulation protocols, as well as initial pointers to possible, exciting future developments Keywords: brain oscillations, EEG, MEG, rTMS, TACs, tDCS Conference: XI International Conference on Cognitive Neuroscience (ICON XI), Palma, Mallorca, Spain, 25 Sep - 29 Sep, 2011. Presentation Type: Symposium: Oral Presentation Topic: Symposium 10: Entraining the brain? Effects of rhythmic brain stimulation protocols on oscillatory brain activity and behavior Citation: Thut G and Romei V (2011). Entraining the brain? Effects of rhythmic brain stimulation protocols on oscillatory brain activity and behaviour. Conference Abstract: XI International Conference on Cognitive Neuroscience (ICON XI). doi: 10.3389/conf.fnhum.2011.207.00524 Copyright: The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers. They are made available through the Frontiers publishing platform as a service to conference organizers and presenters. The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated. Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed. For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions. Received: 09 Nov 2011; Published Online: 28 Nov 2011. * Correspondence: Dr. Gregor Thut, University of Glasgow, Glasgow, United Kingdom, gregor.thut@glasgow.ac.uk Login Required This action requires you to be registered with Frontiers and logged in. To register or login click here. Abstract Info Abstract The Authors in Frontiers Gregor Thut Vincenzo Romei Google Gregor Thut Vincenzo Romei Google Scholar Gregor Thut Vincenzo Romei PubMed Gregor Thut Vincenzo Romei Related Article in Frontiers Google Scholar PubMed Abstract Close Back to top Javascript is disabled. Please enable Javascript in your browser settings in order to see all the content on this page.

Perceptual Object Extraction Based on Saliency and Clustering

Object-based visual attention has received an increasing interest in recent years. Perceptual object is the basic attention unit of object-based visual attention. The definition and extraction of perceptual objects is one of the key technologies in object-based visual attention computation model. A novel perceptual object definition and extraction method is proposed in this paper. Based on Gestalt theory and visual feature integration theory, perceptual object is defined using homogeneity region, salient region and edges. An improved saliency map generating algorithm is employed first. Based on the saliency map, salient edges are extracted. Then graph-based clustering algorithm is introduced to get homogeneity regions in the image. Finally an integration strategy is adopted to combine salient edges and homogeneity regions to extract perceptual objects. The proposed perceptual object extraction method has been tested on lots of natural images. Experiment results and analysis are presented in this paper also. Experiment results show that the proposed method is reasonable and valid.

Looks count: Computing and constructing visually expressive mass customized housing

AbstractThis paper introduces new research that seeks to develop low-cost, high quality, mass customizable building assembly systems that provide visually rich design variations for housing or other small structures. The building systems are intended to be tailored for particular cultures and communities by incorporating vernacular decorative design into the assembly design. Two complementary research areas are brought together in this work: shape grammars and digital fabrication. The visual, aesthetic aspects of the research are explored through shape grammars. The physical design and manufacturing aspects are explored through advanced digital design and fabrication technologies, and in particular, build on recent work on monomaterial assemblies with interlocking components that can be fabricated with computer numerical control machines and assembled easily by hand. The long-term objective of this research is the development of formal, visual–physical grammars with rules that generate complete computer-assisted design/computer-assisted manufacturing data for fabrication of full-scale components for assembly design variations. This paper reports on the first phase of this research: pilot studies for prototype assembly systems that incorporate vernacular languages from different parts of the world. The results of these studies are very promising, and demonstrate a spectrum of strategies for embedding visual properties in structural systems. Important next steps in this research are outlined. If successful, this work will lead to new solutions for low-cost, easily manufactured housing, which is especially critical in developing countries and for postdisaster environments. These new housing solutions will not only provide shelter but also support important cultural values through the integration of familiar visual design features. Beyond the specific context of housing and building assemblies, the research has the potential to impact the design and manufacture of designed artifacts on many scales and in many domains, especially in domains where visual aesthetics need to be considered jointly with physical, structural, or material requirements, and where design customization and variation is important.

The shape of words in the brain

The principle of arbitrariness in language assumes that there is no intrinsic relationship between linguistic signs and their referents. However, a growing body of sound-symbolism research suggests the existence of some naturally-biased mappings between phonological properties of labels and perceptual properties of their referents ( Maurer, Pathman, & Mondloch, 2006). We present new behavioural and neurophysiological evidence for the psychological reality of sound-symbolism. In a categorisation task that captures the processes involved in natural language interpretation, participants were faster to identify novel objects when label–object mappings were sound-symbolic than when they were not. Moreover, early negative EEG-waveforms indicated a sensitivity to sound-symbolic label–object associations (within 200 ms of object presentation), highlighting the non-arbitrary relation between the objects and the labels used to name them. This sensitivity to sound-symbolic label–object associations may reflect a more general process of auditory–visual feature integration where properties of auditory stimuli facilitate a mapping to specific visual features.

Is there room for the BBC in the mental lexicon? On the recognition of acronyms

It has been suggested that acronyms like BBC are processed like real words. This claim has been based on improved performance with acronyms in the Reicher-Wheeler task, the letter string matching task, the visual feature integration task, and the N400 component in event-related potential (ERP) studies. Unfortunately, in all these tasks performance on acronyms resembled performance on pseudowords more than performance on words. To further assess the similarity of acronyms and words, we focused on the meaning of the acronyms and used masked priming to examine whether target words can be primed to the same extent with associatively related acronyms as with associatively related words. Such priming was possible at a stimulus onset asynchrony (SOA) of 84 ms. In addition, the priming of the acronyms did not depend on the letter case in which they were presented: The target word "books" was primed as much by isbn and iSbN as by ISBN.

Brain Activity Patterns Uniquely Supporting Visual Feature Integration after Traumatic Brain Injury

Brain Activity Patterns Uniquely Supporting Visual Feature Integration after Traumatic Brain Injury

Medial temporal lobe activity during complex discrimination of faces, objects, and scenes: Effects of viewpoint

The medial temporal lobe (MTL), a set of heavily interconnected structures including the hippocampus and underlying entorhinal, perirhinal and parahippocampal cortex, is traditionally believed to be part of a unitary system dedicated to declarative memory. Recent studies, however, demonstrated perceptual impairments in amnesic individuals with MTL damage, with hippocampal lesions causing scene discrimination deficits, and perirhinal lesions causing object and face discrimination deficits. The degree of impairment on these tasks was influenced by the need to process complex conjunctions of features: discriminations requiring the integration of multiple visual features caused deficits, whereas discriminations that could be solved on the basis of a single feature did not. Here, we address these issues with functional neuroimaging in healthy participants as they performed a version of the oddity discrimination task used previously in patients. Three different types of stimuli (faces, scenes, novel objects) were presented from either identical or different viewpoints. Consistent with studies in patients, we observed increased perirhinal activity when participants distinguished between faces and objects presented from different, compared to identical, viewpoints. The posterior hippocampus, by contrast, showed an effect of viewpoint for both faces and scenes. These findings provide convergent evidence that the MTL is involved in processes beyond long-term declarative memory and suggest a critical role for these structures in integrating complex features of faces, objects, and scenes into view-invariant, abstract representations.

AN fMRI EXAMINATION OF VISUAL INTEGRATION IN SCHIZOPHRENIA

Behavioral and electrophysiological studies of schizophrenia have consistently demonstrated impairments in the integration of visual features into unified perceptual representations. Specific brain regions involved in this dysfunction, however, remain to be clarified. This study used functional Magnetic Resonance Imaging (fMRI) to examine the relative involvement of visual cortex areas (involved in form perception) and parietal and frontal regions (involved in attention), in the visual integration impairment in schizophrenia. Fourteen patients with schizophrenia and 14 healthy controls were compared on behavioral performance and data acquired via fMRI while completing a contour integration task that had previously been used to identify a visual integration deficit in schizophrenia. The schizophrenia patients demonstrated poorer visual integration than controls. Analyses of peak signal change indicated that while the groups were equivalent in area V1, the schizophrenia group demonstrated reduced signal in areas V2-V4, which are the earliest regions sensitive to global configurations of stimuli. Moreover, whereas the control group demonstrated greater recruitment of prefrontal and parietal areas during perception of integrated forms compared to random stimuli, the schizophrenia group demonstrated greater recruitment of frontal regions during perception of random stimuli. The two groups differed on brain regions involved in form perception even when they were matched on accuracy levels. The visual integration disturbance in schizophrenia involves both deficient basic visual processes (beginning as early as occipital region V2), as well as reduced feedback from visual attention regions that normally serves to amplify relevant visual representations relative to irrelevant information.

Interactions between top-down and stimulus-driven processes in visual feature integration

Event Abstract Back to Event Interactions between top-down and stimulus-driven processes in visual feature integration Marc Schipper1*, Udo Ernst2, Klaus Pawelzik2 and Manfred Fahle1 1 Bremen University, Department for Human Neurobiology, Center for Cognitive Sciences, Germany 2 Bremen University, Department for Theoretical Physics, Center for Cognitive Sciences, Germany Perception of visual scenes requires the brain to link local image features into global contexts. Contour integration is such an example grouping colinearily aligned edge elements to form coherent percepts. Theoretical and modeling studies demonstrated that purely stimulus-driven mechanisms, as implemented by feedforward or recurrent network architectures, are well suited to explain this cognitive function. However, recent empirical work showed that top-down attention can strongly modulate contour integration. By combining psychophysical with electrophysiological methods, we studied how strongly prior expectations shape contour integration. These empirical techniques were complemented by model simulations to uncover the putative neural substrates and mechanisms underlying contour integration.Subjects participated in two experiments with identical visual stimuli but different behavioural tasks: a detection task (A) and a discrimination task (B). Stimuli consisted of vertical or horizontal ellipses formed by colinearily aligned Gabor elements embedded in a field of Gabors with random orientations and positions. Each hemifield could contain either (i) one vertical, (ii) one horizontal, or (iii) no ellipse. All combinations of these three basic configurations were possible, resulting in nine stimulus categories. In experiment A participants replied ‘yes’ whenever one stimulus contained at least one ellipse, in experiment B observers replied ‘yes’ only when a target was present (either a horizontal or vertical ellipse).The psychophysical data demonstrate a pronounced influence of higher cognitive processes on contour integration: In the discrimination task, reaction times (RT) are consistently shorter for targets than for distractors. The presence of redundant targets (e.g. two horizontal ellipses instead of only one horizontal ellipse) also shortens RTs. These first two effects were consistent with our expectations. Moreover we discovered an additional bias in RT for horizontal ellipses (~70 ms shorter than for vertical ellipses).In EEG recordings, we find pronounced differences in event-related potentials (ERPs) between stimulations with versus without the presence of contours. These differences appear at about 110-160 ms after stimulus onset in the occipital regions of the cortex. In the same regions the evoked potentials were substantially modulated by the number of contours present (~140 ms after stimulus onset) and depending on the behavioural task (~230 ms after stimulus onset). Psychophysical and electrophysiological results are qualitatively consistent: The larger the RT differences, the more dissimilar are ERPs in occipital regions. Moreover, phenomenological modeling reveals that the horizontal bias and task-induced effects either constructively or destructively combine in a multiplicative way. This may lead to much lower RTs when e.g. a horizontal bias combines with a horizontal target, or to a mutual cancellation of the different RT effects when e.g. a horizontal bias combines with a vertical target. Acknowledgments:This work was supported by the BMBF as part of the National Bernstein Network for Computational Neuroscience. Conference: Bernstein Conference on Computational Neuroscience, Frankfurt am Main, Germany, 30 Sep - 2 Oct, 2009. Presentation Type: Oral Presentation Topic: Sensory processing Citation: Schipper M, Ernst U, Pawelzik K and Fahle M (2009). Interactions between top-down and stimulus-driven processes in visual feature integration. Front. Comput. Neurosci. Conference Abstract: Bernstein Conference on Computational Neuroscience. doi: 10.3389/conf.neuro.10.2009.14.158 Copyright: The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers. They are made available through the Frontiers publishing platform as a service to conference organizers and presenters. The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated. Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed. For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions. Received: 28 Aug 2009; Published Online: 28 Aug 2009. * Correspondence: Marc Schipper, Bremen University, Department for Human Neurobiology, Center for Cognitive Sciences, Bremen, Germany, schipper.marc@gmail.com Login Required This action requires you to be registered with Frontiers and logged in. To register or login click here. Abstract Info Abstract The Authors in Frontiers Marc Schipper Udo Ernst Klaus Pawelzik Manfred Fahle Google Marc Schipper Udo Ernst Klaus Pawelzik Manfred Fahle Google Scholar Marc Schipper Udo Ernst Klaus Pawelzik Manfred Fahle PubMed Marc Schipper Udo Ernst Klaus Pawelzik Manfred Fahle Related Article in Frontiers Google Scholar PubMed Abstract Close Back to top Javascript is disabled. Please enable Javascript in your browser settings in order to see all the content on this page.

When an object is more than a binding of its features: Evidence for two mechanisms of visual feature integration

People spontaneously integrate the features of visual events into episodic structures that are reactivated if their ingredients match aspects of the current input. Feature integration has been attributed to either the detection of feature conjunctions or the ad hoc binding of feature codes (e.g., by neural synchronization). We report evidence suggesting that both kinds of integration mechanisms coexist. Replicating earlier findings, repeating one visual feature facilitated performance but only if other visual features were also repeated. However, this effect was more pronounced with real objects as compared to arbitrary combinations of shapes and colours. Moreover, the real-object effect was restricted to visual feature integration but did not extend to visuomotor integration, suggesting that the underlying mechanism subserves perception only. We suggest a dual-process feature-integration model that distinguishes between ad hoc binding, which operates on any possible combination of features alike, and conjunction detection, which selectively operates on familiar feature combinations.