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Vision Research Mar 2003Double E(2)N(2) scaling, i.e. magnifying size and contrast, allows modelling of the deterioration of face recognition performance with increasing eccentricity (E) and...
Double E(2)N(2) scaling, i.e. magnifying size and contrast, allows modelling of the deterioration of face recognition performance with increasing eccentricity (E) and the size (N) of the set from which a target face has to be identified. E(2) and N(2) values represent the eccentricities and set sizes at which stimulus size and contrast must double in order to keep performance unchanged, whilst parameter K represents the multiplicative interaction between E and N. In the current study we investigated whether double E(2)N(2) scaling can model performance deterioration with increasing eccentricity and set size in letter perception too. Contrast sensitivity for letter perception was investigated as a function of letter size at N=1-8 and E=0 degrees -10 degrees. The superimposition of contrast sensitivity functions produced two scaling surfaces, one for letter size and another for contrast, which allowed modelling of the changes in letter perception with increasing E and N. With increasing eccentricity/set size the change of scale was much faster for contrast than letter size. Thus, in letter perception, contrast scaling was more important than spatial scaling. When compared with face perception, the change of spatial scale with increasing eccentricity was slower for letters whereas the change of contrast scale was similar for both. With increasing set size the changes of both spatial and contrast scales are faster for faces. In spatial scaling the interaction between eccentricity and set size was similar for letters and faces whereas in contrast scaling letters showed no interaction. Thus, letter perception was less affected by eccentricity and set size than face perception.
Topics: Adult; Contrast Sensitivity; Humans; Models, Psychological; Pattern Recognition, Visual; Photic Stimulation; Size Perception; Visual Fields
PubMed: 12639603
DOI: 10.1016/s0042-6989(02)00685-5 -
Cortex; a Journal Devoted To the Study... Feb 2019We experience our body as a 3D, volumetric object in the world. Measures of our conscious body image, in contrast, have investigated the perception of body size along... (Randomized Controlled Trial)
Randomized Controlled Trial
We experience our body as a 3D, volumetric object in the world. Measures of our conscious body image, in contrast, have investigated the perception of body size along one or two dimensions at a time. There is, thus, a discrepancy between existing methods for measuring body image and our subjective experience of having 3D body. Here we assessed in a sample of healthy adults the perception of body size in terms of its 1D length and 3D volume. Participants were randomly assigned to two groups using different measuring units (other body part and non-body object). They estimated how many units would fit in a perceived size of body segments and the whole body. The patterns of length and volume misperception across judged segments were determined as their perceived size proportional to their actual size. The pattern of volume misperception paints the representation of 3D body proportions resembling those of a somatosensory homunculus. The body parts with a smaller actual surface area relative to their volume were underestimated more. There was a tendency for body parts underestimated in volume to be overestimated in length. Perceived body proportions thus changed as a function of judgement type while showing a similarity in magnitude of the absolute estimation error, be it an underestimation of volume or overestimation of length. The main contribution of this study is assessing the body image as a 3D body representation, and thus extending beyond the conventional 'allocentric' focus to include the body on the inside. Our findings highlight the value of studying the perceptual distortions "at the baseline", i.e., in healthy population, so as to advance the understanding of the nature of perceptual distortions in clinical conditions.
Topics: Adult; Body Image; Body Size; Female; Humans; Judgment; Male; Self Concept; Size Perception; Young Adult
PubMed: 30471452
DOI: 10.1016/j.cortex.2018.10.016 -
PloS One 2017It is well documented that people are good at the rapid representation of multiple objects in the form of ensemble summary statistics of different types (numerosity, the...
It is well documented that people are good at the rapid representation of multiple objects in the form of ensemble summary statistics of different types (numerosity, the average feature, the variance of features, etc.). However, there is not enough clarity regarding the links between statistical domains. The relations between different-type summaries (numerosity and the mean) are of particular interest, since they can shed light on (1) a very general functional organization of ensemble processing and (2) mechanisms of statistical computations (whether averaging takes into account numerical information, as in regular statistics). Here, we show no correlation between the precision of estimated numerosity and that of the estimated mean. We also found that people are very good at dividing attention between numerosity and the mean size of a single set (Experiment 1); however, they show some cost of dividing attention between two same-type (two numerosities or two mean sizes, Experiment 2) and two different-type (one numerosity and one mean size, Experiment 3) summaries when each summary is ascribed to a different set. These results support the idea of domain specificity of numerosity and mean size perception, which also implies that, unlike regular statistics, computing the mean does not require numerosity information. We also conclude that computational capacity of ensemble statistics is more limited by encoding several ensembles than computing several summaries.
Topics: Adolescent; Cues; Female; Humans; Male; Pattern Recognition, Visual; Photic Stimulation; Size Perception; Statistics as Topic; Time Factors; Young Adult
PubMed: 28957361
DOI: 10.1371/journal.pone.0185452 -
PloS One 2021When grasping an object, the opening between the fingertips (grip aperture) scales with the size of the object. If an object changes in size, the grip aperture has to be...
When grasping an object, the opening between the fingertips (grip aperture) scales with the size of the object. If an object changes in size, the grip aperture has to be corrected. In this study, it was investigated whether such corrections would influence the perceived size of objects. The grasping plan was manipulated with a preview of the object, after which participants initiated their reaching movement without vision. In a minority of the grasps, the object changed in size after the preview and participants had to adjust their grasping movement. Visual feedback was manipulated in two experiments. In experiment 1, vision was restored during reach and both visual and haptic information was available to correct the grasp and lift the object. In experiment 2, no visual information was provided during the movement and grasps could only be corrected using haptic information. Participants made reach-to-grasp movements towards two objects and compared these in size. Results showed that participants adjusted their grasp to a change in object size from preview to grasped object in both experiments. However, a change in object size did not bias the perception of object size or alter discrimination performance. In experiment 2, a small perceptual bias was found when objects changed from large to small. However, this bias was much smaller than the difference that could be discriminated and could not be considered meaningful. Therefore, it can be concluded that the planning and execution of reach-to-grasp movements do not reliably affect the perception of object size.
Topics: Adult; Female; Hand; Humans; Male; Movement; Psychomotor Performance; Size Perception; Young Adult
PubMed: 34520478
DOI: 10.1371/journal.pone.0248084 -
Vision Research Sep 2018Evaluating the effects of print size and retinal eccentricity on reading speed is important for identifying the constraints faced by people with central-field loss....
Evaluating the effects of print size and retinal eccentricity on reading speed is important for identifying the constraints faced by people with central-field loss. Previous work on English reading showed that 1) reading speed increases with print size until a critical print size (CPS) is reached, and then remains constant at a maximum reading speed (MRS), and 2) as eccentricity increases, MRS decreases and CPS increases. Here we extend this work to Korean, a language with more complex orthography. We recruited 6 Korean native speakers (mean age = 22) and measured their reading speed in central vision (0°) and peripheral vision (10° in the lower field). 900 Korean sentences (average 8.25 words) were created with frequently-occurring beginner-level words, presented using a rapid serial visual presentation (RSVP) paradigm. Data for English reading were obtained from Chung, Mansfield & Legge, Vision Research, 1998, for comparison. MRS was similar for Korean and English at 0° (713 vs. 787 wpm), but decreased faster with eccentricity for Korean. CPS was larger for Korean than for English regardless of eccentricity, but increased with eccentricity similarly for both languages. From 0 to 10°, MRS decreased by a factor of 6.5 for Korean and 2.8 for English, and CPS increased by a factor of 11.7 for Korean and 10.2 for English. Korean reading speed is more affected by retinal eccentricity than English, likely due to additional within-character crowding from more complex orthography. Korean readers with central-field loss may experience more difficulty than English readers.
Topics: Adolescent; Adult; Female; Humans; Language; Male; Mass Media; Reading; Republic of Korea; Retina; Size Perception; Young Adult
PubMed: 30003891
DOI: 10.1016/j.visres.2018.06.013 -
Cognitive Science Nov 2018Pupillary responses and associated vergence eye movements were monitored during imagery of objects of differing sizes ("large" or "small") from varying distances ("near"...
Pupillary responses and associated vergence eye movements were monitored during imagery of objects of differing sizes ("large" or "small") from varying distances ("near" or "far"). Objects' imagined size and distance affected oculomotor behavior. Objects visualized as "far" resulted in the larger pupil dilations and smaller visual angle, while small objects imagined "near" were associated with smaller pupils in contrast to relatively larger pupils when imagined as "far" away. Furthermore, near objects resulted in larger visual angle, and particularly, vergence adjustments were observed that were dependent on imagined size and distance of the small objects. The findings are consistent with the idea that imagery emulates perception, also at the embodied level of oculomotor behaviors.
Topics: Adult; Distance Perception; Eye Movements; Female; Fixation, Ocular; Humans; Imagination; Male; Photic Stimulation; Pupil; Size Perception
PubMed: 30302788
DOI: 10.1111/cogs.12684 -
Journal of Vision Mar 2020While visual size preferences regarding still objects have been investigated and linked to the "canonical size" effect-where preferred on-screen size was significantly...
While visual size preferences regarding still objects have been investigated and linked to the "canonical size" effect-where preferred on-screen size was significantly related to objects' real-world size-the visual size preferences related to moving images of natural scenes has not been researched. In this study, we measured the preferred size of moving images of natural scenes and short duration and investigated the effect of viewing distance on size preferences. Our results showed that the preferred size varied strongly depending on content, and we found moving images' canonical size effect. The preferred size in images of scenery was significantly larger than in images of persons, and there was a positive correlation between the preferred size and the real-world physical size of the main subjects in the images. When the viewing distance was doubled, the preferred size increased about 10% as a ratio to screen size-in contrast to the findings of a previous study. While the rationale for these findings is not yet clear, our analysis suggests that neither the motion component in the images nor the nature of their background area are contributing factors. We suggest that environment, viewing distance, and screen size may contribute to this effect.
Topics: Adult; Distance Perception; Female; Humans; Male; Middle Aged; Motion Perception; Psychophysics; Size Perception; Young Adult
PubMed: 32207770
DOI: 10.1167/jov.20.3.6 -
Current Biology : CB Jan 2009When one lifts two objects of equal weight and appearance but different size, the smaller object usually feels heavier. New results show that this size-weight illusion... (Review)
Review
When one lifts two objects of equal weight and appearance but different size, the smaller object usually feels heavier. New results show that this size-weight illusion can be inverted after extensive training with objects in which the natural size-weight relationship is artificially reversed.
Topics: Adaptation, Psychological; Humans; Illusions; Learning; Size Perception; Weight Perception
PubMed: 19138585
DOI: 10.1016/j.cub.2008.10.039 -
Experimental Brain Research Nov 2012Humans routinely estimate the size and weight of objects. Yet, when lifting two objects of equal weight but different size, they often perceive the smaller object as...
Humans routinely estimate the size and weight of objects. Yet, when lifting two objects of equal weight but different size, they often perceive the smaller object as being heavier. This size-weight illusion (SWI) is known to have a lesser effect on motor control of object lifting. How the nervous system combines "weight" and "size" cues with prior experience and whether these cues are differentially integrated for perception and sensorimotor action is still not fully understood. Therefore, we assessed not only whether the experience of size biases weight perception, but also if experience of weight biases the size perception of objects. Further, to investigate differences between perceptual and motor systems for cue-experience integration, participants haptically explored the weight of an object with one hand and then shaped the aperture of their other hand to indicate its perceived size. Results-First, next to a SWI, healthy adults (N = 21) perceived lighter objects as being smaller and heavier objects as being larger, demonstrating a weight-size illusion (WSI). Second, participants were more susceptible to either the SWI or WSI. Third, aperture of the non-exploring hand was scaled to perceived weight and not to physical size. Hand openings were consistently smaller than physical size, with SWI-sensitive participants being significantly more affected than WSI-sensitive subjects. We conclude: first, both size and weight perceptions are biased by prior experience. Weight perception is biased by expectations of size, while size perception is influenced by the expectancy of weight. Second, humans have the tendency to use one cue predominantly for both types of perception. Third, combining perceived weight with expected size influenced hand motor control, while online haptic feedback was largely ignored. Finally, we present a processing model underlying the size-weight cue integration for the perceptual and motor system.
Topics: Adaptation, Psychological; Adult; Cues; Data Interpretation, Statistical; Female; Hand; Humans; Illusions; Judgment; Male; Photic Stimulation; Psychomotor Performance; Size Perception; Weight Perception; Young Adult
PubMed: 22968739
DOI: 10.1007/s00221-012-3247-9 -
Journal of Vision Oct 2021The ability to estimate spatial extent is an important feature of the visual system. A previous study showed that perceived sizes of stimuli shrank after adaptation to a...
The ability to estimate spatial extent is an important feature of the visual system. A previous study showed that perceived sizes of stimuli shrank after adaptation to a dense texture and that this density-size aftereffect was modulated by the degree of density. In this study, we found that the aftereffect was also modulated by the temporal density of the adapting texture. The test stimuli were two circles, and the adapting stimulus had a dotted texture. The adapting texture refreshed every 67 to 500 ms, or not at all (static), during the adaptation. The results showed that the aftereffects from a refreshing stimulus were larger than those under the static condition. On the other hand, density adaptation lacked such enhancement. This result indicates that repetitive presentation of an adapting texture enhanced the density-size cross-aftereffect. The fact that density modulation occurs in both the spatial and temporal domains is consistent with the theory of magnitude, which assumes that the processing of the magnitude estimation of space, time, and numbers share a common cortical basis.
Topics: Adaptation, Physiological; Figural Aftereffect; Humans; Motion Perception; Size Perception
PubMed: 34668931
DOI: 10.1167/jov.21.11.11