Independent Feature Processing in both Vision for Perception and Vision for Action

Grasping the Müller-Lyer illusion: The contributions of vision for perception in action

The visual control of skilled actions, such as reaching and grasping, requires fundamentally different computations from those mediating our perception of the world. These differences in the computational requirements for vision for action and vision for perception are reflected in the organization of the two prominent visual streams of processing that arise from primary visual cortex in the primate brain. Although the ventral stream projecting to inferotemporal cortex mediates the visual processing underlying our visual experience of the world, the dorsal stream projecting to the posterior parietal cortex mediates the visual control of skilled actions. Specialized visual-motor modules have emerged in the posterior parietal cortex for the visual control of eye, hand, and arm movements. Although the identification of goal objects and the selection of an appropriate course of action depend on the perceptual machinery of the ventral stream and associated cognitive modules in the temporal and frontal lobes, the execution of the subsequent goal-directed action is mediated by dedicated online control systems in the dorsal stream and associated motor areas. Ultimately then, both streams work together in the production of goal-directed actions.

Vision for action and vision for perception have been suggested to be mediated by overlapping yet dissociable mechanisms. Recent evidence provided basic psychophysical support for this suggestion. In particular, it has been shown that Weber's law, the decrease in visual resolution with object size, does not affect the maximum grip aperture (MGA) between the fingers prior to grasp. Several studies replicated this result, but have argued that grasping may still obey Weber's law at early movement stages. Here, we show that this apparent adherence to Weber's law was confounded by task demands. Specifically, subjects were asked to keep their fingers closed prior to grasp, which encouraged them to open their fingers faster for larger compared to smaller objects. In two experiments, we tested this proposal by disentangling the effects of velocity from those of Weber's law. In Experiment 1, subjects were asked to keep their fingers open wide-apart prior to grasp, which encouraged them to close their fingers faster, rather than slower, to smaller objects. Now, the apparent adherence to Weber's law was reversed, and higher resolution was found for larger compared to smaller objects, thus indicating a "reversed" Weber's law. In Experiment 2, we manipulated task demands to equate aperture velocities across different objects sizes. When velocity was equated, no effects of Weber's law were found throughout the movement. These findings show that previous studies have confounded visual resolution with fingers' velocity, which led to an erroneous conclusion that Weber's law affected grasping at early stages of the movement.

Visual size illusions have been shown to affect perceived object size but not the aperture of the hand when reaching to those same objects. Thus, vision for perception is said to be dissociated from vision for action. The present study examines the effect of visual-position and visual-shape illusions on both the visually perceived center of an object and the position of a grasp on that object when a balanced lift is required. The results for both experiments show that although the illusions influence both the perceived and the grasped estimates of the center position, the grasp position is more veridical. This partial dissociation is discussed in terms of its implications for streams of visual processing.

Both sighted and blind individuals can readily interpret meaning behind everyday real-world sounds. In sighted listeners, we previously reported that regions along the bilateral posterior superior temporal sulci (pSTS) and middle temporal gyri (pMTG) are preferentially activated when presented with recognizable action sounds. These regions have generally been hypothesized to represent primary loci for complex motion processing, including visual biological motion processing and audio-visual integration. However, it remained unclear whether, or to what degree, life-long visual experience might impact functions related to hearing perception or memory of sound-source actions. Using functional magnetic resonance imaging (fMRI), we compared brain regions activated in congenitally blind versus sighted listeners in response to hearing a wide range of recognizable human-produced action sounds (excluding vocalizations) versus unrecognized, backward-played versions of those sounds. Here we show that recognized human action sounds commonly evoked activity in both groups along most of the left pSTS/pMTG complex, though with relatively greater activity in the right pSTS/pMTG by the blind group. These results indicate that portions of the postero-lateral temporal cortices contain domain-specific hubs for biological and/or complex motion processing independent of sensory-modality experience. Contrasting the two groups, the sighted listeners preferentially activated bilateral parietal plus medial and lateral frontal networks, while the blind listeners preferentially activated left anterior insula plus bilateral anterior calcarine and medial occipital regions, including what would otherwise have been visual-related cortex. These global-level network differences suggest that blind and sighted listeners may preferentially use different memory retrieval strategies when attempting to recognize action sounds.

It is typically assumed that perception for action and object recognition are subserved by functionally and neuroanatomically distinct processing streams in the brain. However, recent evidence challenges this classical view and suggests an interaction between both visual processing streams. While previous studies showed an influence of object perception on action-related tasks, we investigated whether action representations facilitate visual object recognition. In order to address this question, two briefly displayed masked objects were sequentially presented, either affording congruent or incongruent motor interactions. We found superior naming accuracy for object pairs with congruent as compared to incongruent motor interactions (Experiment 1). This action priming effect indicates that action representations can facilitate object recognition. We further investigated the nature of the representations underlying this action priming effect. The effect was absent when the prime stimulus was presented as a word (Experiment 2). Thus, the action priming effect seems to rely on action representations specified by visual object information. Our findings suggest that processes of object-directed action influence object recognition.

Event Abstract Back to Event Spatial vision in insects: How visual information processing is facilitated by an active flight and gaze strategy Martin Egelhaaf1*, Roland Kern1 and Jens P. Lindemann1 1 Bielefeld University, Neurobiology & CITEC, Germany Flying insects, such as blowflies and bees rely on the image flow on their eyes (“optic flow”) solving spatial tasks as diverse as collision avoidance and local navigation, i.e. localizing a previously learnt inconspicuous goal on the basis of landmark cues. In free flight flies and bees exhibit characteristic behavioural actions to shape the dynamics of the optic flow. By employing a saccadic flight and gaze strategy they squeeze rotations into brief and rapid turns leaving most of the flight time for various types of translational prototypical movements. Separation of rotational and translational optic flow components by a behavioural strategy is reasonable , since only the optic flow component induced by translations contains information about the relative distance of environmental structures from the animal. By combined electrophysiological analysis and model simulations we analyzed how during rotational and translational self-motion information about the spatial layout and the textural properties of both experimenter-designed and natural environments are represented at the different processing stages of the visual motion pathway. Only two major conclusions shall be mentioned here: (1) during intersaccadic translational flight, the mechanisms of local motion detection segregate in a computationally cheap way natural sceneries into their depth structure: nearby objects pop out in the activity profile of retinotopic arrays of local motion detectors, whereas more distant structures evoke only negligible responses. (2) Even after spatial pooling of local motion signals by the dendritic trees of the wide-field cells in the lobula complex of flies and bees, these distance dependent response modulations persist. Hence, these neurons, which are traditionally conceived as rotation sensors being involved in mediating compensatory optomotor responses, provide information about the spatial properties of the environment. In conclusion, the neural processing of spatial information in flies and bees is greatly facilitated by their saccadic flight and gaze strategy. This active vision strategy enables the nervous system to solve apparently complex spatial vision tasks in a computationally parsimonious way. Thus, by making use of the closed action–perception loop in a smart way, insects with their tiny brains are capable of performing extraordinarily well even on extremely fast timescales of some ten milliseconds. Acknowledgements The work in our lab is supported by the Deutsche Forschungsgemeinschaft (DFG) Keywords: motion vision, Spatial Vision, Optic Flow, collision avoidance, navigation, fly, Honeybee, Bumblebee, Flight control Conference: International Conference on Invertebrate Vision, Fjälkinge, Sweden, 1 Aug - 8 Aug, 2013. Presentation Type: Oral presentation preferred Topic: Motion vision Citation: Egelhaaf M, Kern R and Lindemann JP (2019). Spatial vision in insects: How visual information processing is facilitated by an active flight and gaze strategy. Front. Physiol. Conference Abstract: International Conference on Invertebrate Vision. doi: 10.3389/conf.fphys.2013.25.00044 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: 25 Feb 2013; Published Online: 09 Dec 2019. * Correspondence: Prof. Martin Egelhaaf, Bielefeld University, Neurobiology & CITEC, Bielefeld, D-33501, Germany, martin.egelhaaf@uni-bielefeld.de 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 Martin Egelhaaf Roland Kern Jens P Lindemann Google Martin Egelhaaf Roland Kern Jens P Lindemann Google Scholar Martin Egelhaaf Roland Kern Jens P Lindemann PubMed Martin Egelhaaf Roland Kern Jens P Lindemann 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.

The visual recognition of goal-directed movements is crucial for the learning of actions, and possibly for the understanding of the intentions and goals of others. The discovery of mirror neurons has stimulated a vast amount of research investigating possible links between action perception and action execution [1,2]. However, it remains largely unknown what is the real extent of this putative visuo-motor interaction during visual perception of actions and which relevant computational functions are instead accomplished by possibly purely visual processing.

Event Abstract Back to Event Studying infant cognition by EEG and ERP Gergely Csibra1* 1 Central European University, Hungary One can measure the functional brain activation of babies for several purposes. First, variations of neural activation measured in controlled situations may reveal how the infant brain works, and when these results are compared across development or with those of adults, they allow insights into early functional development of the cerebral cortex. Second, correlating neural activations with behavioral performance across individuals can generate hypotheses about the neural mechanisms that underlie overt behavior, and may lead to a better understanding of individual differences or developmental disorders. Finally, functional brain activations in infants can be used to test, support, or falsify theories of infant cognitive development—as long as such activations could be plausibly identified as neural 'signatures' of certain kinds of representations or computations. In this talk, I will illustrate this third, most modest, usage of neuroscientific approach to infant cognition by four examples. First, we used event-related potentials to test whether 5-month-old infants are subject to the audio-visual McGurk illusion - a question that would be particularly difficult to answer by purely behavioral methods. Second, event-related gamma-band oscillations revealed that 4-month-olds interpret certain dynamic facial expressions (such as direct gaze and eye-brow raise) as communicative signals. This finding was also supported by near-infrared spectroscopy (NIRS), which measures haemodynamic changes in the infant brain. Third, similar gamma-band oscillatory responses indicated that learning object labels modify the visual processing of the associated objects in the infant brain. Finally, a recent finding demonstrates how measurements of motor activation during action perception by the attenuation of the sensorimotor alpha waves could be used for disambiguating behavioral findings concerning action interpretation in infants. Electrophysiological techniques provide an excellent tool to study the cognitive development in young infants. Conference: MMN 09 Fifth Conference on Mismatch Negativity (MMN) and its Clinical and Scientific Applications, Budapest, Hungary, 4 Apr - 7 Apr, 2009. Presentation Type: Oral Presentation Topic: Invited Talk Citation: Csibra G (2009). Studying infant cognition by EEG and ERP. Conference Abstract: MMN 09 Fifth Conference on Mismatch Negativity (MMN) and its Clinical and Scientific Applications. doi: 10.3389/conf.neuro.09.2009.05.004 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: 19 Mar 2009; Published Online: 19 Mar 2009. * Correspondence: Gergely Csibra, Central European University, Budapest, Hungary, csibrag@ceu.hu 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 Gergely Csibra Google Gergely Csibra Google Scholar Gergely Csibra PubMed Gergely Csibra 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.

The distinction between operations in visual processing that are parallel and preattentive and those that are serial and attentional receives both theoretical and empirical support. According to Treisman's feature-integration theory, independent features are available preattentively, but attention is required to veridically combine features into objects. Certain evidence supporting this theory is consistent with a different interpretation, which was tested in four experiments. The first experiment compared the detection of features and feature combinations while eliminating a factor that confounded earlier comparisons. The resulting priority of access to combinatorial information suggests that features and nonlocal combinations of features are not connected solely by a bottom-up hierarchical convergence. Causes of the disparity between the results of Experiment 1 and the results of previous research were investigated in three subsequent experiments. The results showed that of the two confounded factors, it was the difference in the mapping of alternatives onto responses, not the differing attentional demands of features and objects, that underlaid the results of the previous research. The present results are thus counterexamples to the feature-integration theory. Aspects of this theory are shown to be subsumed by more general principles, which are discussed in terms of attentional processes in the detection of features, objects, and stimulus alternatives.

Multisensory neurons in superior colliculus display inverse effectiveness (IE); responses to multimodal stimuli are greater when the most effective unisensory stimulus produces a weak response (e.g. Meredith & Stein, 1983). Recently, fMRI evidence for inverse effectiveness has been found in superior temporal sulcus (Stevenson & James, 2009), a region implicated in multisensory integration (e.g. Barraclough et al., 2009) and human action perception (e.g. Blake & Shiffrar, 2008). While the relationship between neural IE and multisensory perception and performance remains unclear, and evidence suggests that not all multimodal processes adhere strictly to the IE rule (Holmes, 2007), behavioral studies have shown that the effect of auditory cues on visual processing is greater when the visual signal is relatively weak (e.g., Collignon et al., 2008). Previously, we found that sensitivity to point-light walkers improves when paired with footstep sounds. Because sounds' influence on vision depends upon the strength of the visual signal, we hypothesized that heard footsteps should increase detection sensitivity only when the visual stimulus is weak. To test this hypothesis, we analyzed data from Thomas & Shiffrar (2010) to see whether the detectability of the visual signal determined the degree to which footstep sounds improved detection of point-light walkers. We obtained percent correct for each movie presented in silence (range 33–100%). We then split all movies into two groups based on difficulty. A 3 × 2 mixed measures ANOVA with sound condition as the between-subjects factor (silence, tones, footsteps) and difficulty as the within-subjects factor (easy vs. hard) revealed a main effect of sound, difficulty and a sound X difficulty interaction. Subsequent analyses revealed that footsteps improved visual sensitivity only for “hard” movies, supporting our hypothesis. A follow-up experiment replicated and extended these results.

Perception and understanding of dispositions and intentions of others through their actions are of immense importance for adaptive daily-life behavior and social communication. Here we ask whether, and, if so, how this ability is impaired in adolescents who were born premature and suffer early periventricular damage, periventricular leukomalacia (PVL) that affects brain connectivity. The visual event arrangement (EA) task was administered to PVL patients and two control groups, premature-born and term-born adolescents without brain abnormalities on a magnetic resonance imaging scan. Performance on the EA task was significantly lower in PVL patients as compared with controls. No difference was found between premature-born participants without lesions and term-born controls. Performance on the EA task was inversely related to the volumetric extent of lesions in the parieto-occipital regions of both hemispheres and, in particular, to the right temporal periventricular lesions. Whereas our earlier work reveals that compromised visual processing of biological motion, impairments in visual navigation, and other visual-perceptual disabilities in PVL patients are associated with parieto-occipital lesions, difficulties in the visual EA task solely are specifically linked to the right temporal periventricular lesions. For the first time, we show that the severity of the right temporal PVL can serve as a predictor of the ability for perception and understanding of others' actions. We assume that impairments in this ability in PVL patients are caused by disrupted brain connectivity to the right temporal cortex, a key node of the social brain.

Computational models are fundamentally important for testing the feasibility of theories of the visual processing of body movements and for deriving well-defined theoretical predictions that can be tested experimentally. A computational model is proposed for the recognition of transitive and nontransitive hand actions from real videos that reproduces several key neurophysiological properties of the action perception system. Limitations of the proposed model, along with novel predictions and areas for future research, are discussed.