scholarly journals Cue-selective adaptation operates on a separable encoding of stereo and texture information

2019 ◽  
Author(s):  
Evan Cesanek ◽  
Fulvio Domini
Keyword(s):  
Visual Information ◽  
Physical Object ◽  
Physical Reality ◽  
Selective Adaptation ◽  
Visual Signals ◽  
Grip Aperture ◽  
Visual Inputs ◽  
Constant Bias ◽  
Depth Dimension ◽  
Object Depth

AbstractTo perform accurate movements, the sensorimotor system must maintain a delicate calibration of the mapping between visual inputs and motor outputs. Previous work has focused on the mapping between visual inputs and individual locations in egocentric space, but little attention has been paid to the mappings that support interactions with 3D objects. In this study, we investigated sensorimotor adaptation of grasping movements targeting the depth dimension of 3D paraboloid objects. Object depth was specified by separately manipulating binocular disparity (stereo) and texture gradients. At the end of each movement, the fingers closed down on a physical object consistent with one of the two cues, depending on the condition (haptic-for-texture or haptic-for-stereo). Unlike traditional adaptation paradigms, where relevant spatial properties are determined by a single dimension of visual information, this method enabled us to investigate whether adaptation processes can selectively adjust the influence of different sources of visual information depending on their relationship to physical depth. In two experiments, we found short-term changes in grasp performance consistent with a process of cue-selective adaptation: the slope of the grip aperture with respect to a reliable cue (correlated with physical reality) increased, whereas the slope with respect to the unreliable cue (uncorrelated with physical reality) decreased. In contrast, slope changes did not occur during exposure to a set of stimuli where both cues remained correlated with physical reality, but one was rendered with a constant bias of 10 mm; the grip aperture simply became uniformly larger or smaller, as in standard adaptation paradigms. Overall, these experiments support a model of cue-selective adaptation driven by correlations between error signals and input values (i.e., supervised learning), rather than mismatched haptic and visual signals.

Differential Involvement of Neurons in the Dorsal and Ventral Premotor Cortex During Processing of Visual Signals for Action Planning

2006 ◽  
Vol 95 (6) ◽  
pp. 3596-3616 ◽  
Author(s):  
Eiji Hoshi ◽  
Jun Tanji
Keyword(s):  
Neuronal Activity ◽  
Visual Information ◽  
Visual Cues ◽  
Target Location ◽  
Premotor Cortex ◽  
Action Planning ◽  
Visual Signals ◽  
Visual Cue ◽  
Ventral Premotor Cortex ◽  
Neuron Response

We examined neuronal activity in the dorsal and ventral premotor cortex (PMd and PMv, respectively) to explore the role of each motor area in processing visual signals for action planning. We recorded neuronal activity while monkeys performed a behavioral task during which two visual instruction cues were given successively with an intervening delay. One cue instructed the location of the target to be reached, and the other indicated which arm was to be used. We found that the properties of neuronal activity in the PMd and PMv differed in many respects. After the first cue was given, PMv neuron response mostly reflected the spatial position of the visual cue. In contrast, PMd neuron response also reflected what the visual cue instructed, such as which arm to be used or which target to be reached. After the second cue was given, PMv neurons initially responded to the cue's visuospatial features and later reflected what the two visual cues instructed, progressively increasing information about the target location. In contrast, the activity of the majority of PMd neurons responded to the second cue with activity reflecting a combination of information supplied by the first and second cues. Such activity, already reflecting a forthcoming action, appeared with short latencies (<400 ms) and persisted throughout the delay period. In addition, both the PMv and PMd showed bilateral representation on visuospatial information and motor-target or effector information. These results further elucidate the functional specialization of the PMd and PMv during the processing of visual information for action planning.

Effects of Learning on Smooth Pursuit During Transient Disappearance of a Visual Target

2003 ◽  
Vol 90 (2) ◽  
pp. 972-982 ◽  
Author(s):  
Laurent Madelain ◽  
Richard J. Krauzlis
Keyword(s):  
Smooth Pursuit ◽  
Visual Target ◽  
Visual Signals ◽  
Control Group ◽  
Long Term Effects ◽  
Velocity Gain ◽  
Visual Inputs ◽  
Before And After ◽  
Pursuit Velocity

Previous research has demonstrated learning in the pursuit system, but it is unclear whether these effects are the result of changes in visual or motor processing. The ability to maintain smooth pursuit during the transient disappearance of a visual target provides a way to assess pursuit properties in the absence of visual inputs. To study the long-term effects of learning on nonvisual signals for pursuit, we used an operant conditioning procedure. By providing a reinforcing auditory stimulus during periods of accurate tracking, we increased the pursuit velocity gain during target blanking from 0.59 in the baseline session to 0.89 after 8 to 10 daily sessions of training. Learning also reduced the occurrence of saccades. The learned effects generalized to untrained target velocities and persisted in the presence of a textured visual background. In a yoked-control group, the reinforcer was independent of the subjects' responses, and the velocity gain remained unchanged (from 0.6 to 0.63, respectively, before and after training). In a control group that received no reinforcer, gain increased slightly after repetition of the task (from 0.63 to 0.71, respectively, before and after training). Using a model of pursuit, we show that these effects of learning can be simulated by modifying the gain of an extra-retinal signal. Our results demonstrate that learned contingencies can increase eye velocity in the absence of visual signals and support the view that pursuit is regulated by extra-retinal signals that can undergo long-term plasticity.

scholarly journals A two-level computer vision-based information processing method for improving the performance of human–machine interaction-aided applications

2020 ◽  
Author(s):  
Osama Alfarraj ◽  
Amr Tolba
Keyword(s):  
Computer Vision ◽  
Information Processing ◽  
Visual Information ◽  
Information Gain ◽  
Processing System ◽  
Human Machine Interaction ◽  
Visual Inputs ◽  
Level Data ◽  
Processing Errors ◽  
Fully Connected

Abstract The computer vision (CV) paradigm is introduced to improve the computational and processing system efficiencies through visual inputs. These visual inputs are processed using sophisticated techniques for improving the reliability of human–machine interactions (HMIs). The processing of visual inputs requires multi-level data computations for achieving application-specific reliability. Therefore, in this paper, a two-level visual information processing (2LVIP) method is introduced to meet the reliability requirements of HMI applications. The 2LVIP method is used for handling both structured and unstructured data through classification learning to extract the maximum gain from the inputs. The introduced method identifies the gain-related features on its first level and optimizes the features to improve information gain. In the second level, the error is reduced through a regression process to stabilize the precision to meet the HMI application demands. The two levels are interoperable and fully connected to achieve better gain and precision through the reduction in information processing errors. The analysis results show that the proposed method achieves 9.42% higher information gain and a 6.51% smaller error under different classification instances compared with conventional methods.

scholarly journals African elephants ( Loxodonta africana ) recognize visual attention from face and body orientation

2014 ◽  
Vol 10 (7) ◽  
pp. 20140428 ◽  
Author(s):  
Anna F. Smet ◽  
Richard W. Byrne
Keyword(s):  
Visual Attention ◽  
Visual Information ◽  
Loxodonta Africana ◽  
Visual Signals ◽  
Body Orientation ◽  
Visual Perspective ◽  
African Elephants ◽  
Intended Audience ◽  
Communicative Signals ◽  
To Receive

How do animals determine when others are able and disposed to receive their communicative signals? In particular, it is futile to make a silent gesture when the intended audience cannot see it. Some non-human primates use the head and body orientation of their audience to infer visual attentiveness when signalling, but whether species relying less on visual information use such cues when producing visual signals is unknown. Here, we test whether African elephants ( Loxodonta africana ) are sensitive to the visual perspective of a human experimenter. We examined whether the frequency of gestures of head and trunk, produced to request food, was influenced by indications of an experimenter's visual attention. Elephants signalled significantly more towards the experimenter when her face was oriented towards them, except when her body faced away from them. These results suggest that elephants understand the importance of visual attention for effective communication.

scholarly journals The Influence of Visual Perturbations on the Neural Control of Limb Stiffness

2009 ◽  
Vol 101 (1) ◽  
pp. 246-257 ◽  
Author(s):  
Jeremy Wong ◽  
Elizabeth T. Wilson ◽  
Nicole Malfait ◽  
Paul L. Gribble
Keyword(s):  
Visual Information ◽  
Motor System ◽  
Neural Control ◽  
Visual Signals ◽  
Neural Systems ◽  
Lateral Direction ◽  
Limb Stiffness ◽  
Environmental Instability ◽  
Stiffness Control ◽  
Visual Perturbation

To adapt to novel unstable environments, the motor system modulates limb stiffness to produce selective increases in arm stability. The motor system receives information about the environment via somatosensory and proprioceptive signals related to the perturbing forces and visual signals indicating deviations from an expected hand trajectory. Here we investigated whether subjects modulate limb stiffness during adaptation to a purely visual perturbation. In a first experiment, measurements of limb stiffness were taken during adaptation to an elastic force field (EF). Observed changes in stiffness were consistent with previous reports: subjects increased limb stiffness and did so only in the direction of the environmental instability. In a second experiment, stiffness changes were measured during adaptation to a visual perturbing environment that magnified hand-path deviations in the lateral direction. In contrast to the first experiment, subjects trained in this visual task showed no accompanying change in stiffness, despite reliable improvements in movement accuracy. These findings suggest that this sort of visual information alone may not be sufficient to engage neural systems for stiffness control, which may depend on sensory signals more directly related to perturbing forces, such as those arising from proprioception and somatosensation.

Reaching-related Neurons in Superior Parietal Area 5: Influence of the Target Visibility

2016 ◽  
Vol 28 (11) ◽  
pp. 1828-1837 ◽  
Author(s):  
Emiliano Brunamonti ◽  
Aldo Genovesio ◽  
Pierpaolo Pani ◽  
Roberto Caminiti ◽  
Stefano Ferraina
Keyword(s):  
Visual Information ◽  
Posterior Parietal Cortex ◽  
Hand Movement ◽  
Visual Signals ◽  
Hand Position ◽  
Movement Initiation ◽  
Starting Position ◽  
Area 5 ◽  
Posterior Parietal ◽  
Target Visibility

Reaching movements require the integration of both somatic and visual information. These signals can have different relevance, depending on whether reaches are performed toward visual or memorized targets. We tested the hypothesis that under such conditions, therefore depending on target visibility, posterior parietal neurons integrate differently somatic and visual signals. Monkeys were trained to execute both types of reaches from different hand resting positions and in total darkness. Neural activity was recorded in Area 5 (PE) and analyzed by focusing on the preparatory epoch, that is, before movement initiation. Many neurons were influenced by the initial hand position, and most of them were further modulated by the target visibility. For the same starting position, we found a prevalence of neurons with activity that differed depending on whether hand movement was performed toward memorized or visual targets. This result suggests that posterior parietal cortex integrates available signals in a flexible way based on contextual demands.

scholarly journals Hierarchical LSTM with Adjusted Temporal Attention for Video Captioning

2017 ◽  
Author(s):  
Jingkuan Song ◽  
Lianli Gao ◽  
Zhao Guo ◽  
Wu Liu ◽  
Dongxiang Zhang ◽  
...  
Keyword(s):  
Visual Information ◽  
Language Model ◽  
Attention Mechanism ◽  
Visual Signals ◽  
Temporal Attention ◽  
Video Captioning ◽  
Visual Words ◽  
Overall Performance ◽  
Language Context ◽  
Made In

Recent progress has been made in using attention based encoder-decoder framework for video captioning. However, most existing decoders apply the attention mechanism to every generated words including both visual words (e.g., “gun” and "shooting“) and non-visual words (e.g. "the“, "a”).However, these non-visual words can be easily predicted using natural language model without considering visual signals or attention.Imposing attention mechanism on non-visual words could mislead and decrease the overall performance of video captioning.To address this issue, we propose a hierarchical LSTM with adjusted temporal attention (hLSTMat) approach for video captioning. Specifically, the proposed framework utilizes the temporal attention for selecting specific frames to predict related words, while the adjusted temporal attention is for deciding whether to depend on the visual information or the language context information. Also, a hierarchical LSTMs is designed to simultaneously consider both low-level visual information and deep semantic information to support the video caption generation. To demonstrate the effectiveness of our proposed framework, we test our method on two prevalent datasets: MSVD and MSR-VTT, and experimental results show that our approach outperforms the state-of-the-art methods on both two datasets.

scholarly journals Smell what you hardly see: Odors assist categorization in the human visual cortex

2021 ◽  
Author(s):  
Diane Rekow ◽  
Jean-Yves Baudouin ◽  
Karine Durand ◽  
Arnaud Leleu
Keyword(s):  
Visual Information ◽  
Right Hemisphere ◽  
Visual Stimulation ◽  
Temporal Cortex ◽  
Visual Response ◽  
Visual Categorization ◽  
Visual Inputs ◽  
Scalp Electroencephalogram ◽  
Human Faces ◽  
The Brain

Visual categorization is the brain ability to rapidly and automatically respond to widely variable visual inputs in a category-selective manner (i.e., distinct responses between categories and similar responses within categories). Whether category-selective neural responses are purely visual or can be influenced by other sensory modalities remains unclear. Here, we test whether odors modulate visual categorization, expecting that odors facilitate the neural categorization of congruent visual objects, especially when the visual category is ambiguous. Scalp electroencephalogram (EEG) was recorded while natural images depicting various objects were displayed in rapid 12-Hz streams (i.e., 12 images / second) and variable exemplars of a target category (either human faces, cars, or facelike objects in dedicated sequences) were interleaved every 9th stimulus to tag category-selective responses at 12/9 = 1.33 Hz in the EEG frequency spectrum. During visual stimulation, participants (N = 26) were implicitly exposed to odor contexts (either body, gasoline or baseline odors) and performed an orthogonal cross-detection task. We identify clear category-selective responses to every category over the occipito-temporal cortex, with the largest response for human faces and the lowest for facelike objects. Critically, body odor boosts the response to the ambiguous facelike objects (i.e., either perceived as nonface objects or faces) over the right hemisphere, especially for participants reporting their presence post-stimulation. By contrast, odors do not significantly modulate other category-selective responses, nor the general visual response recorded at 12 Hz, revealing a specific influence on the categorization of congruent ambiguous stimuli. Overall, these findings support the view that the brain actively uses cues from the different senses to readily categorize visual inputs, and that olfaction, which is generally considered as poorly functional in humans, is well placed to disambiguate visual information.

scholarly journals Stereopsis in Sports: Visual Skills and Visuomotor Integration Models in Professional and Non-Professional Athletes

2021 ◽  
Vol 18 (21) ◽  
pp. 11281
Author(s):  
Valentina Presta ◽  
Costanza Vitale ◽  
Luca Ambrosini ◽  
Giuliana Gobbi
Keyword(s):  
Athletic Performance ◽  
Visual Information ◽  
Spatial Vision ◽  
Sport Performance ◽  
Professional Athletes ◽  
Visuomotor Integration ◽  
Sport Expertise ◽  
Visual Inputs ◽  
Visual Skills ◽  
Relevant Variables

Visual skills in sport are considered relevant variables of athletic performance. However, data on the specific contribution of stereopsis—as the ability to perceive depth—in sport performance are still scarce and scattered in the literature. The aim of this review is therefore to take stock of the effects of stereopsis on the athletic performance, also looking at the training tools to improve visual abilities and potential differences in the visuomotor integration processes of professional and non-professional athletes. Dynamic stereopsis is mainly involved in catching or interceptive actions of ball sports, whereas strategic sports use different visual skills (peripheral and spatial vision) due to the sport-specific requirements. As expected, professional athletes show better visual skills as compared to non-professionals. However, both non-professional and professional athletes should train their visual skills by using sensory stations and light boards systems. Non-professional athletes use the visual inputs as the main method for programming motor gestures. In contrast, professional athletes integrate visual information with sport expertise, thus, they encode the match (or the athletic performance) through a more complex visuomotor integration system. Although studies on visual skills and stereopsis in sports still appear to be in their early stages, they show a large potential for both scientific knowledge and technical development.

scholarly journals Visual influences on auditory spatial learning

2008 ◽  
Vol 364 (1515) ◽  
pp. 331-339 ◽  
Author(s):  
Andrew J King
Keyword(s):  
Visual Information ◽  
Critical Role ◽  
Spatial Cues ◽  
Auditory Space ◽  
Auditory Responses ◽  
Neural Representations ◽  
Visual Inputs ◽  
Mature Brain ◽  
Auditory Systems ◽  
The Brain

The visual and auditory systems frequently work together to facilitate the identification and localization of objects and events in the external world. Experience plays a critical role in establishing and maintaining congruent visual–auditory associations, so that the different sensory cues associated with targets that can be both seen and heard are synthesized appropriately. For stimulus location, visual information is normally more accurate and reliable and provides a reference for calibrating the perception of auditory space. During development, vision plays a key role in aligning neural representations of space in the brain, as revealed by the dramatic changes produced in auditory responses when visual inputs are altered, and is used throughout life to resolve short-term spatial conflicts between these modalities. However, accurate, and even supra-normal, auditory localization abilities can be achieved in the absence of vision, and the capacity of the mature brain to relearn to localize sound in the presence of substantially altered auditory spatial cues does not require visuomotor feedback. Thus, while vision is normally used to coordinate information across the senses, the neural circuits responsible for spatial hearing can be recalibrated in a vision-independent fashion. Nevertheless, early multisensory experience appears to be crucial for the emergence of an ability to match signals from different sensory modalities and therefore for the outcome of audiovisual-based rehabilitation of deaf patients in whom hearing has been restored by cochlear implantation.

Sign in / Sign up

Export Citation Format

Share Document