Ciba Foundation symposium ; 184
[1st ed.] VIII, 347 s. : obr., tab. ; 23 cm
- MeSH
- Neurophysiology MeSH
- Ocular Physiological Phenomena MeSH
- Vision, Ocular physiology MeSH
- Publication type
- Congress MeSH
- Conspectus
- Lékařské vědy. Lékařství
- NML Fields
- fyziologie
- neurovědy
- oftalmologie
Visual attention modulates the firing rate of neurons in many primate cortical areas. In V4, a cortical area in the ventral visual pathway, spatial attention has also been shown to reduce the tendency of neurons to fire closely separated spikes (burstiness). A recent model proposes that a single mechanism accounts for both the firing rate enhancement and the burstiness reduction in V4, but this has not been empirically tested. It is also unclear if the burstiness reduction by spatial attention is found in other visual areas and for other attentional types. We therefore recorded from single neurons in the medial superior temporal area (MST), a key motion-processing area along the dorsal visual pathway, of two rhesus monkeys while they performed a task engaging both spatial and feature-based attention. We show that in MST, spatial attention is associated with a clear reduction in burstiness that is independent of the concurrent enhancement of firing rate. In contrast, feature-based attention enhances firing rate but is not associated with a significant reduction in burstiness. These results establish burstiness reduction as a widespread effect of spatial attention. They also suggest that in contrast to the recently proposed model, the effects of spatial attention on burstiness and firing rate emerge from different mechanisms.
- MeSH
- Biological Clocks physiology MeSH
- Macaca mulatta MeSH
- Brain Waves physiology MeSH
- Nerve Net physiology MeSH
- Attention physiology MeSH
- Space Perception physiology MeSH
- Visual Fields physiology MeSH
- Visual Cortex physiology MeSH
- Animals MeSH
- Check Tag
- Male MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
2nd ed. elektronický optický disk (CD-ROM)
Defekty zorného pole bývají častou funkční poruchou, se kterou se v praxi setkáváme. V práci jsou uvedeny výsledky perimetrických vyšetření zdravých dobrovolníkú (odborníků i laiků), kteří simulovali určité poruchy zorného pole na počítačovém perimetru Hupmhrey.
Visual field defects are a common feature of functional visual loss at the ophthalmology praxis. The author reports the perimetry results of healthy volunteers (ophthalmology specialists and laymen, too), who have fabricated specific visual field defects.
The present research was motivated by the routine digital media practice of producing page layouts as composite images that include several unrelated pictures. We investigated whether or how visually highlighting affective and positional components of pictures in a viewer's field of vision might influence viewer perception and evaluation of the composite image. We examined combinations of visual, spatial, and affective features of cues in composite images to learn whether they affected the viewer's attentional capture of other affective information in the composite image and viewer's affective evaluations. The manipulation check of the feature combinations (positive/negative affect, presence/absence of highlighted color, central/peripheral position) showed significant effects of these features and their interactions on viewers' eye movements. On the other hand, we observed only a small effect on viewers' affective evaluations. Our results suggested that media page layout designers might manipulate the viewer's attention by visual and positional adjustments of affective components in composite images. Future researchers might use this study's design to better understand the human perception of real media images.
- MeSH
- Affect physiology MeSH
- Arousal physiology MeSH
- Adult MeSH
- Middle Aged MeSH
- Humans MeSH
- Young Adult MeSH
- Cues * MeSH
- Eye Movements physiology MeSH
- Attention physiology MeSH
- Photic Stimulation MeSH
- Learning physiology MeSH
- Visual Perception physiology MeSH
- Check Tag
- Adult MeSH
- Middle Aged MeSH
- Humans MeSH
- Young Adult MeSH
- Male MeSH
- Female MeSH
- Publication type
- Journal Article MeSH
Existing research indicates that the shape of various facial regions is linked to perceived attractiveness and perceived formidability. Interestingly, little evidence shows that people directly focus on these specific facial regions during judgments of attractiveness and formidability, and there is little support for the notion that the levels of attractiveness and formidability affect raters' visual attention. We employed eye-tracking to examine visual attention (the number of fixations and dwell time) in 40 women and 37 men, while they assessed 45 male faces in life-sized photographs for attractiveness and formidability. The facial photographs were grouped by varying levels of attractiveness and formidability (low, medium, and high). Our results showed that regardless of the characteristics rated, both men and women paid the most visual attention to the eyes, nose, mouth, and forehead regions. We found statistically discernible variation in visual attention in relation to the rater's sex or target's attractiveness levels for other facial features (the chin, cheeks, or ears), but these differences may not be substantial enough to have practical implications. We suggest that the eyes, the nose, and the mouth regions play a central role in the evolution of face perception as regions most salient to the acquisition of informative cues about others. Further, during both attractiveness and formidability judgments, men looked longer at the stimuli than women did, which may hint at increased difficulty of this task for men, possibly because they compare themselves with the stimuli. Additionally, irrespective of sex, raters looked marginally longer at faces with a medium level of formidability than at those with a high formidability level, which may reflect ambiguity of these stimuli and uncertainty regarding assessment. We found no other significantly relationships between the target's attractiveness and formidability levels and the rater's visual attention to whole faces.
- MeSH
- Adult MeSH
- Beauty MeSH
- Humans MeSH
- Judgment MeSH
- Young Adult MeSH
- Face * MeSH
- Attention * physiology MeSH
- Facial Recognition physiology MeSH
- Eye-Tracking Technology MeSH
- Choice Behavior physiology MeSH
- Visual Perception physiology MeSH
- Check Tag
- Adult MeSH
- Humans MeSH
- Young Adult MeSH
- Male MeSH
- Female MeSH
- Publication type
- Journal Article MeSH
Previous studies have demonstrated that humans have a remarkable capacity to memorise a large number of scenes. The research on memorability has shown that memory performance can be predicted by the content of an image. We explored how remembering an image is affected by the image properties within the context of the reference set, including the extent to which it is different from its neighbours (image-space sparseness) and if it belongs to the same category as its neighbours (uniformity). We used a reference set of 2,048 scenes (64 categories), evaluated pairwise scene similarity using deep features from a pretrained convolutional neural network (CNN), and calculated the image-space sparseness and uniformity for each image. We ran three memory experiments, varying the memory workload with experiment length and colour/greyscale presentation. We measured the sensitivity and criterion value changes as a function of image-space sparseness and uniformity. Across all three experiments, we found separate effects of 1) sparseness on memory sensitivity, and 2) uniformity on the recognition criterion. People better remembered (and correctly rejected) images that were more separated from others. People tended to make more false alarms and fewer miss errors in images from categorically uniform portions of the image-space. We propose that both image-space properties affect human decisions when recognising images. Additionally, we found that colour presentation did not yield better memory performance over grayscale images.
- MeSH
- Adult MeSH
- Middle Aged MeSH
- Humans MeSH
- Neural Networks, Computer * MeSH
- Memory physiology MeSH
- Mental Recall physiology MeSH
- Recognition, Psychology physiology MeSH
- Pattern Recognition, Visual physiology MeSH
- Photic Stimulation methods MeSH
- Check Tag
- Adult MeSH
- Middle Aged MeSH
- Humans MeSH
- Male MeSH
- Female MeSH
- Publication type
- Journal Article MeSH
INTRODUCTION: The sharpness of lateral peaks is a visually helpful clinical feature in high-speed videokymographic (VKG) images indicating vertical phase differences and mucosal waves on the vibrating vocal folds and giving insights into the health and pliability of vocal fold mucosa. This study aims at investigating parameters that can be helpful in objectively quantifying the lateral peak sharpness from the VKG images. METHOD: Forty-five clinical VKG images with different degrees of sharpness of lateral peaks were independently evaluated visually by three raters. The ratings were compared to parameters obtained by automatic image analysis of the vocal fold contours: Open Time Percentage Quotients (OTQ) and Plateau Quotients (PQ). The OTQ parameters were derived as fractions of the period during which the vocal fold displacement exceeds a predetermined percentage of the vibratory amplitude. The PQ parameters were derived similarly but as a fraction of the open phase instead of a period. RESULTS: The best correspondence between the visual ratings and the automatically derived quotients were found for the OTQ and PQ parameters derived at 95% and 80% of the amplitude, named OTQ95, PQ95, OTQ80 and PQ80. Their Spearman's rank correlation coefficients were in the range of 0.73 to 0.77 (P < 0.001) indicating strong relationships with the visual ratings. The strengths of these correlations were similar to those found from inter-rater comparisons of visual evaluations of peak sharpness. CONCLUSION: The Open time percentage and Plateau quotients at 95% and 80% of the amplitude stood out as the possible candidates for capturing the sharpness of the lateral peaks with their reliability comparable to that of visual ratings.
- MeSH
- Video Recording * MeSH
- Automation MeSH
- Biomechanical Phenomena MeSH
- Time Factors MeSH
- Phonation * MeSH
- Vocal Cords diagnostic imaging physiopathology MeSH
- Image Interpretation, Computer-Assisted * MeSH
- Voice Quality * MeSH
- Kymography * MeSH
- Laryngoscopy MeSH
- Humans MeSH
- Judgment MeSH
- Voice Disorders diagnostic imaging physiopathology MeSH
- Predictive Value of Tests MeSH
- Retrospective Studies MeSH
- Laryngeal Mucosa diagnostic imaging physiopathology MeSH
- Vibration MeSH
- Visual Perception * MeSH
- Check Tag
- Humans MeSH
- Publication type
- Journal Article MeSH
V předchozích experimentech (Nekovarova et al., 2007) jsme ukázali, že makaci (Macaca mulatta) jsou schopni se orientovat v reálném prostoru na základě abstraktních vizuálních stimulů promítaných na obrazovku počítače. Vizuální stimuly byly dvojího druhu: „prostorové" („konfigurační"), které byly navrženy jako prostorová reprezentace reálného „odpověďového prostoru" a „neprostorové", které byly tvořeny jen jednoduchými obrazci bez implicitní prostorové informace. V prezentovaných experimentech jsme zkoumali schopnost makaků orientovat se podle prostorových stimulů, které jsme rotovali ve frontální rovině oproti reálnému „odpovědbvému prostoru" nebo u kterých jsme transformovali jejich geometrické vlastnosti. U prezentovaných stimulů jsme měnili velikost úhlů a poměr délky stran. Zkoumali jsme, jakou strategii používají makaci k reprezentaci těchto stimulů.
In previous experiments we demonstrated that macaque monkeys (Macaca mulatta) were able to orient in a real space according to abstract spatial stimuli presented on a computer screen. We used visual stimuli of both types: „spatial“ (designed as a representation of the real „response space“) and „non-spatial“ (simple patterns without any implicit spatial information). In present experiments we studied an ability of macaque monkeys to orient in the real space according to the spatial stimuli rotated in frontal plane against the real space or according to stimuli with transformed geometric features. We changed the geometric features of stimuli: angles and the lengths of walls. We studied which strategy the monkeys used to represent such abstract spatial stimuli.
In this study we propose a new tool for the perceptual assessment of voice quality. For its design, we have adapted the Simplified Vocal Profile Analysis so that the new tool features two main characteristics: (1) the ordinal scalar degrees of the original protocol are turned into a visual analog scale; and (2) the original paper-based version of the protocol is now a computer-based implementation. In order to assess the reliability of the new tool, five phoneticians listened to 12 different speakers and evaluated their voice quality using the proposed tool. Inter-rater agreement was then calculated using the Intraclass Correlation Coefficient. The results show that high agreement was reached for most of the perceptual settings of the protocol. Yet more investigations seem necessary into the continuous nature of the perceptual dimensions making up the voice quality of a speaker. As a preliminary approach to the graphical possibilities that the visual analog scale offers to the Simplified Vocal Profile Analysis, we explore the usefulness of multiple dot plots and propose an adaptation of the Bland-Altman plot to be used in pairwise comparisons. In this study, these visualization techniques are tested on two pairs of identical twins.
- MeSH
- Voice Quality * MeSH
- Humans MeSH
- Speech Production Measurement MeSH
- Computers * MeSH
- Reproducibility of Results MeSH
- Visual Analog Scale MeSH
- Check Tag
- Humans MeSH
- Publication type
- Journal Article MeSH
