How motor maps are organized while imagining actions is an intensely debated issue. It particularly unclear whether imagery relies on action-specific representations in premotor and posterior parietal cortices. This study tackled this issue by attempting to decode the content of from spatial patterns Blood Oxygen Level Dependent (BOLD) signals recorded frontoparietal network. During fMRI-scanning, 20 right-handed volunteers worked three experimental conditions one baseline condition. In...

Previous behavioral research suggests enhanced local visual processing in individuals with autism spectrum disorders (ASDs). Here we used functional MRI and population receptive field (pRF) analysis to test whether the response selectivity of human cortex is atypical high-functioning ASDs compared neurotypical, demographically matched controls. For each voxel, fitted a pRF model fMRI signals measured while participants viewed flickering bar stimuli traversing field. In most extrastriate...

Simulation theory proposes motor imagery (MI) to be a simulation based on representations also used for execution (ME). Nonetheless, it is unclear how far they use the same neural code. We multivariate pattern analysis (MVPA) and representational similarity (RSA) describe associated with MI ME within frontoparietal network. During functional magnetic resonance imaging scanning, 20 volunteers imagined or executed 3 different types of right-hand actions. Results MVPA showed that these actions...

What determines where we look? Theories of attentional guidance hold that image features and task demands govern fixation behavior, while differences between observers are interpreted as a "noise-ceiling" strictly limits predictability fixations. However, recent twin studies suggest genetic basis gaze-trace similarity for given stimulus. This leads to the question how individuals differ in their gaze behavior what may explain these differences. Here, investigated fixations >100 human adults...

Abstract Perception is subjective. Even basic judgments, like those of visual object size, vary substantially between observers and also across the field within same observer. The way in which system determines size objects remains unclear, however. We hypothesize that inferred from neuronal population activity V1 predict idiosyncrasies cortical functional architecture should therefore explain individual differences judgments. Here we show results novel behavioural methods magnetic resonance...

Individuals differ in where they fixate on a face, with some looking closer to the eyes while others prefer mouth region. These individual biases are highly robust, generalize from lab outside world, and have been associated social cognition disorders. However, it is unclear, whether these specific faces or influenced by domain-general mechanisms of vision. Here, we juxtaposed hypotheses testing face fixation inanimate objects. We analyzed >1.8 million fixations toward objects complex...

Automatic segmentation of anatomical structures in medical images is a valuable tool for efficient computer-aided radiotherapy and surgery planning an enabling technology dynamic adaptive radiotherapy. This paper presents the design, algorithms validation new software automatic CT used treatment planning. A coarse to fine approach followed that consists presegmentation, anatomic orientation structure segmentation. No user input or priori information about image content required. In body...

GENERAL COMMENTARY article Front. Hum. Neurosci., 16 July 2012Sec. Cognitive Neuroscience Volume 6 - 2012 | https://doi.org/10.3389/fnhum.2012.00200

Faces are salient social stimuli whose features attract a stereotypical pattern of fixations. The implications this gaze behavior for perception and brain activity largely unknown. Here, we characterize quantify retinotopic bias implied by typical toward faces, which leads to eyes mouth appearing most often in the upper lower visual field, respectively. We found that adult human system is tuned these contingencies. In two recognition experiments, performance isolated face parts was better...

Population receptive field (pRF) mapping is a widely used approach to measuring aggregate human visual properties by recording non-invasive signals using functional MRI. Despite growing interest, no study date has systematically investigated the effects of different stimulus configurations on pRF estimates from cortex. Here we compared three model-based estimation: size-invariant bars and eccentricity-scaled defined in Cartesian coordinates traveling along cardinal axes, novel simultaneous...

Population receptive field (pRF) analysis is a popular method to infer spatial selectivity of voxels in visual cortex. However, it remains largely untested how stable pRF estimates are over time. Here we measured the intersession reliability parameter for central and near periphery, using combined wedge ring stimulus containing natural images. Sixteen healthy human participants completed two scanning sessions separated by 10–114 days. Individual showed very similar maps V1-V4 on both...

Neurotypical observers show large and reliable individual differences in gaze behavior along several semantic object dimensions. Individual toward faces has been linked to face identity processing, including that of neurotypical observers. Here, we investigated potential biases Super-Recognizers (SRs), individuals with exceptional processing skills. Ten SRs, identified a novel conservative diagnostic framework, 43 controls freely viewed 700 complex scenes depicting more than 5000 objects....

Visual perception can be modulated by sounds. A drastic example of this is the sound-induced flash illusion: when a single accompanied two bleeps, it sometimes perceived in an illusory fashion as consecutive flashes. However, there are strong individual differences proneness to illusion. Some participants experience illusion on almost every trial, whereas others never do. We investigated whether such were reflected structural brain regions whose activity found that strongly and significantly...

AimThe segmentation of organs from a CT scan is time-consuming task, which one hindrance for adaptive radiation therapy. Through deep learning, it possible to automatically delineate organs. Metrics like dice score do not necessarily represent the impact clinical practice. Therefore, evaluation neural network needed verify quality.MethodsIn this work, novel trained on 300 and artificially generated pseudo CBCTs segment bladder, prostate, rectum seminal vesicles cone beam scans. The model...

Visuospatial abilities such as contrast sensitivity and Vernier acuity improve until late in childhood, but the neural mechanisms supporting these changes are poorly understood. We tested to which extent this development might reflect improved spatial of neuronal populations visual cortex. To do this, we measured BOLD-responses areas V1-V4 V3a, whilst 6- 12-year-old children adults watched large-field wedge ring stimuli MRI scanner, then fitted population receptive field (pRF) tuning...

The ventral visual stream of the human brain is subdivided into patches with categorical stimulus preferences, like faces or scenes. However, functional organization within these areas less clear. Here, we used magnetic resonance imaging and vertex-wise tuning models to independently probe spatial face-part preferences in inferior occipital gyrus (IOG) healthy adult males females. majority responses were well explained by Gaussian population curves for both retinotopic location preferred...

Individuals freely viewing complex scenes vary in their fixation behavior. The most prominent and reliable dimension of such individual differences is the tendency to fixate faces. However, much less known about how observers distribute fixations across other body parts persons individuals may this regard. Here, we aimed close gap. We expanded a popular annotated stimulus set (Xu, Jiang, Wang, Kankanhalli, & Zhao, 2014) with 6,365 hand-delineated pixel masks for 1,136 embedded 700 scenes,...

Do different people looking at the same scene perceive individual versions of what’s in front them? If perception is individual, which mechanisms mediate our particular view world? Recent findings have shown systematic observer differences gaze, but it unclear whether fixation patterns translate to impressions scene. Here, we find nouns, verbs and adjectives use when describing identical complex scenes. Crucially, pairwise descriptions could be explained by patterns. The tendency reference...

Salience models for complex scenes typically aim to explain heatmaps or scan-paths. While potentially conflate fixations serving different functions, scan-paths a level of detail which is hard attain. We introduce novel approach, based on the premise that most target objects and belong three functionally meaningful classes: Detection (D), foveating an object first time; Inspection (I), successively targeting details; Return (R), revisiting object, e.g., refresh its representation in memory....

Abstract Do different people looking at the same scene perceive individual versions of what’s in front them? If perception is individual, which mechanisms mediate our particular view world? Recent findings have shown systematic observer differences gaze, but it unclear whether fixation biases translate to divergent impressions scene. Here, we find descriptions observers provide for identical complex scenes. Crucially, patterns predicted pairwise descriptions, particularly use nouns, even...

How does natural gaze behaviour develop? Here, we present data from > 6,500 subjects 5-72 years of age, freely viewing 40 scenes. We find that the development scene is surprisingly protracted. Semantic salience for social features continuously changes until late adolescence and text increases third decade life. Basic oculomotor biases towards image centre along horizontal meridian develop early adulthood, matching developmental in visual sensitivity cortex. Finally, while tendency...

Abstract Adult gaze behaviour towards naturalistic scenes is highly biased semantic object classes. Little known about the ontological development of these biases, nor group-level differences in between adults and preschoolers. Here, we let preschoolers ( n = 34, age 5 years) 42, 18–59 freely view 40 complex containing objects with different attributes to compare their fixation behaviour. Results show that preschool children allocate a significantly smaller proportion dwell time first...