Temporal Phase Affects Spatial Binding in Depth Perception

Perception ◽  
1997 ◽  
Vol 26 (1_suppl) ◽  
pp. 210-210
Author(s):  
H Kojima ◽  
R Blake
Keyword(s):  
Depth Perception ◽  
Spatial Information ◽  
Space Perception ◽  
White Background ◽  
Video Monitor ◽  
Large Screen ◽  
Temporal Phase ◽  
Uncrossed Disparity ◽  
Left And Right ◽  
Method Of Constant Stimuli

The temporal linking of spatial information is essential for coherent space perception. We investigated the effect of the temporal phase of flickering ‘inducers’ in depth perception. Stereo half-images were generated on the left and right halves of a large-screen video monitor and viewed through a mirror stereoscope. The half-images portrayed a solid-black vertically oriented bar seen against a white background. Two brackets immediately flanking this bar could be placed in crossed or uncrossed disparity relative to the bar. A pair of thin white ‘bridging lines’ could appear on the black bar, always at zero disparity. Brackets and bridging lines could be flickered either in-phase or out-of-phase. Observers judged whether the brackets appeared in front of or behind the black bar, with disparity varied over trials according to a method of constant stimuli. We found that when bridging lines were absent, the depth location of the brackets was predictably dependent on disparity sign, with a small bias for “behind” judgements owing to occlusion. When bridging lines and brackets flashed in temporal phase, depth judgements were markedly biased toward “in front”; when the bridging lines and brackets flashed out of phase, this bias was much reduced. This biasing effect also depended on the spatial offset of lines and brackets. We conclude that depth perception is strongly influenced by the temporal phase of the spatial information.

Role of Spatial and Temporal Coincidence in Depth Organization

Perception ◽  
1998 ◽  
Vol 27 (5) ◽  
pp. 541-552 ◽  
Author(s):  
Haruyuki Kojima ◽  
Randolph Blake
Keyword(s):  
Spatial Information ◽  
Space Perception ◽  
Video Monitor ◽  
Lateral Separation ◽  
Temporal Phase ◽  
Spatial Alignment ◽  
Uncrossed Disparity ◽  
Left And Right ◽  
Temporal And Spatial

The linking of spatial information is essential for coherent space perception. A study is reported of the contribution of temporal and spatial alignment for the linkage of spatial elements in terms of depth perception. Stereo half-images were generated on the left and right halves of a large-screen video monitor and viewed through a mirror stereoscope. The half-images portrayed a black vertically oriented bar with two brackets immediately flanking this bar and placed in crossed or uncrossed disparity relative to the bar. A pair of thin white ‘bridging lines' could appear on the black bar, always at zero disparity. Brackets and bridging lines could be flickered either in phase or out of phase. Observers judged whether the brackets appeared in front of or behind the black bar, with disparity varied. Compared to conditions when the bridging lines were absent, depth judgments were markedly biased toward “in front” when bridging lines and brackets flashed in temporal phase; this bias was much reduced when the bridging lines and brackets flashed out of phase. This biasing effect also depended on spatial offset of lines and brackets. However, perception was uninfluenced by the lateral separation between object and brackets.

Spatial perspective choice in ASL

2002 ◽  
Vol 5 (1) ◽  
pp. 3-26 ◽  
Author(s):  
Karen Emmorey ◽  
Barbara Tversky
Keyword(s):  
Cognitive Load ◽  
American Sign Language ◽  
Spatial Information ◽  
English Speakers ◽  
Video Monitor ◽  
Spatial Perspective ◽  
Object Locations ◽  
Shared Space ◽  
Spatial Terms ◽  
Spatial Locations

Two studies investigated the ramifications of encoding spatial locations via signing space for perspective choice in American Sign Language. Deaf signers (“speakers”) described the location of one of two identical objects either to a present addressee or to a remote addressee via a video monitor. Unlike what has been found for English speakers, ASL signers did not adopt their addressee’s spatial perspective when describing locations in a jointly viewed present environment; rather, they produced spatial descriptions utilizing shared space in which classifier and deictic signs were articulated at locations in signing space that schematically mapped to both the speaker’s and addressee’s view of object locations within the (imagined) environment. When the speaker and addressee were not jointly viewing the environment, speakers either adopted their addressee’s perspective via referential shift (i.e. locations in signing space were described as if the speaker were the addressee) or speakers expressed locations from their own perspective by describing locations from their view of a map of the environment and the addressee’s position within that environment. The results highlight crucial distinctions between the nature of perspective choice in signed languages in which signing space is used to convey spatial information and spoken languages in which spatial information is conveyed by lexical spatial terms. English speakers predominantly reduce their addressee’s cognitive load by adopting their addressee’s perspective, whereas in ASL shared space can be used (there is no true addressee or speaker perspective) and in other contexts, reversing speaker perspective is common in ASL and does not increase the addressee’s cognitive load.

scholarly journals Influence of the Instructions on the Performance and Establishment of Memorization Strategies in Space Judgments

2006 ◽  
Vol 9 (2) ◽  
pp. 312-320 ◽  
Author(s):  
Alessandra Ackel Rodrigues ◽  
Susi Lippi Marques
Keyword(s):  
Graduate Students ◽  
Power Function ◽  
Mental Representation ◽  
Spatial Information ◽  
Internal Representation ◽  
Space Perception ◽  
Physical Space ◽  
Visual Space ◽  
Experimental Conditions ◽  
Experimental Configuration

Studies of visual space perception have been assuming that people have an internal representation of the physical space that surrounds them. A variety of psychophysical procedures has been used in an attempt to measure the properties of visual space. The goal of the present study was to evaluate the accuracy of the mental representation and the strategies adopted to acquire and retain visuo-spatial information of a configuration as a function of two types of instructions. Thirty-eight undergraduate and graduate students participated in the study and were distributed in perceptive and mnemonic experimental conditions. The effect of the instructions (intentional and incidental) on the representation of the distances among the objects of the scene was estimated using exponents of power function, based on the reproduction of the distances among the stimuli of the scene. The results revealed that judgments made under intentional instructions were more frequently based on strategies related to the location of the stimuli, whereas judgments originating from incidental instructions were based on strategies related to the name of the stimuli. It was observed that the intentional instruction facilitated a more accurate mental representation of the observed experimental configuration, enhancing participants' performance.

scholarly journals The rodent hippocampus as a bilateral structure: A review of hemispheric lateralization

2017 ◽  
Author(s):  
Jake T. Jordan
Keyword(s):  
Brain Region ◽  
Spatial Information ◽  
Right Hemisphere ◽  
Neural Substrates ◽  
Hemispheric Lateralization ◽  
Hemispheric Differences ◽  
Functional Lateralization ◽  
Left And Right ◽  
The Right ◽  
Behavior And Cognition

AbstractThe left and right rodent hippocampi exhibit striking lateralization in some of the very neural substrates considered to be critical for hippocampal cognitive function. Despite this, there is an overwhelming lack of consideration for hemispheric differences in studies of the rodent hippocampus. Asymmetries identified so far suggest that a bilateral model of the hippocampus will be essential for an understanding of this brain region, and perhaps of the brain more widely. Although hypotheses have been proposed to explain how the left and right hippocampi contribute to behavior and cognition, these hypotheses have either been refuted by more recent studies or have been limited in the scope of data they explain. Here, I will first review data on human and rodent hippocampal lateralization. The implications of these data suggest that considering the hippocampus as a bilateral structure with functional lateralization will be critical moving forward in understanding the function and mechanisms of this brain region. In exploring these implications, I will then propose a hypothesis of the hippocampus as a bilateral structure. This discrete-continuous (DC) hypothesis proposes that the left and right hippocampi contribute to spatial memory and navigation in a complementary manner. Specifically, the left hemisphere stores spatial information as discrete, salient locations and that the right hemisphere represents space continuously, contributing to route computation and flexible spatial navigation. Consideration of hippocampal lateralization in designing future studies may provide insight into the function of the hippocampus and resolve debates concerning its function.

scholarly journals Hemifield-specific control of spatial attention and working memory: Evidence from hemifield crossover costs

2019 ◽  
Author(s):  
Roger W. Strong ◽  
George Alvarez
Keyword(s):  
Working Memory ◽  
Spatial Attention ◽  
Visual Processing ◽  
Spatial Information ◽  
Conclusive Evidence ◽  
Memory Experiment ◽  
Left And Right ◽  
Spatial Interference ◽  
Visual Hemifields ◽  
Specific Control

Attentional tracking and working memory tasks are often performed better when targets are divided evenly between the left and right visual hemifields, rather than contained within a single hemifield (Alvarez & Cavanagh, 2005; Delvenne, 2005). However, this bilateral field advantage does not provide conclusive evidence of hemifield-specific control of attention and working memory, as it can be explained solely from hemifield-limited spatial interference at early stages of visual processing. If control of attention and working memory is specific to each hemifield, maintaining target information should become more difficult as targets move between the two hemifields. Observers in the present study maintained targets that moved either within or between the left and right hemifields, using either attention (Experiment 1) or working memory (Experiment 2). Maintaining spatial information was more difficult when target items moved between the hemifields compared to when target items moved within their original hemifields, consistent with hemifield-specific control of spatial attention and working memory. However, this pattern was not found for maintaining identity information (e.g., color) in working memory (Experiment 3). Together, these results provide evidence that control of spatial attention and working memory is specific to each hemifield, and that hemifield-specific control is a unique signature of spatial processing.

scholarly journals Laterality Does Not Affect the Depth Perception, but Interpupillary Distance

2013 ◽  
Vol 2013 ◽  
pp. 1-5 ◽  
Author(s):  
Murat Aslankurt ◽  
Lokman Aslan ◽  
Adnan Aksoy ◽  
Murat Özdemir ◽  
Şenol Dane
Keyword(s):  
Outcome Measures ◽  
Depth Perception ◽  
Hand Dominance ◽  
Interpupillary Distance ◽  
Left Handed ◽  
Eye Dominance ◽  
Eye Examination ◽  
Left And Right ◽  
The Relationship ◽  
Positive Effect

In this study, which investigates the relationship between the levels of stereopsis with eye and hand dominance or interpupillary distance, 120 healthy young volunteers were investigated. Eye dominance was determined by modified Miles technique following a complete eye examination. Handedness was assessed with the Edinburgh handedness inventory. Interpupillary distance was measured with millimetric ruler. Stereoacuity was measured in both contour (Titmus test) and random dot (TNO test) stereograms. The stereopsis scores were evaluated in terms of hand or eye dominance. The correlation between stereopsis score and interpupillary distance was assessed. Main outcome measures were stereopsis scores according to hand and eye dominance. As a result, right- and left-handed individuals showed no differences in terms of stereopsis. No differences were found in stereopsis scores between right- and left-eye dominant people. There was a correlation between interpupillary distance and the depth of stereopsis (r=-0.248,P<0.05). Contrary to the expectation, the left and right dominant individuals did not differ in levels of stereopsis. Interpupillary distance has a positive effect on stereopsis.

The Effect of Visuo-Spatial Organisation in Recognition-Memory Tasks

Perception ◽  
10.1068/p6095 ◽  
2009 ◽  
Vol 38 (5) ◽  
pp. 763-774
Author(s):  
Laura Petrini ◽  
Kristian Hennings ◽  
Lars Arendt-Nielsen
Keyword(s):  
Recognition Memory ◽  
Spatial Information ◽  
Visual Stimuli ◽  
Spatial Task ◽  
Verbal Task ◽  
Verbal Information ◽  
Spatial Organisation ◽  
Male Volunteers ◽  
Stimulus Probe ◽  
Left And Right

We investigated whether recognition memory benefits when stimuli are organised in a visuo-spatial array. Three different memory tasks were compared: (a) verbal task (what); (b) spatial task (where); (c) combination task, where both verbal and spatial informations were combined together (what/where). We hypothesised that when visual stimuli are organised in a spatial array the recognition is better. Recognition memory was assessed by quantifying the speed of correct responses and the total number of correct responses in a group of male volunteers ( N = 20). Subjects' task was to recognise a stimulus probe from sequences (one versus three) of stimuli. All stimuli appeared randomly in one of nine locations on a 3 × 3 grid. The results show that subjects were faster and more accurate when they had to recognise only spatial information (where) than when they had to recognise verbal information (what) or the combination of both verbal and spatial information (what/where). Additionally, when the stimuli were presented in a spatial array there were benefits for the spatial task, whilst verbal and combination tasks were unaffected. Additionally, asymmetry between left and right hemifields has been found. These findings are discussed with regard to different memory processes that operate independently.

scholarly journals Decay and Interference Effects in Visuospatial Short-Term Memory

Perception ◽  
1996 ◽  
Vol 25 (1) ◽  
pp. 53-64 ◽  
Author(s):  
Graham J Hole
Keyword(s):  
Interstimulus Interval ◽  
Spatial Information ◽  
Short Term Memory ◽  
Mental Representations ◽  
Interference Effects ◽  
Short Term ◽  
Term Memory ◽  
The Third ◽  
Spatial Interval ◽  
Method Of Constant Stimuli

The method of constant stimuli was used to examine the accuracy with which two-dimensional spatial information can be represented in mental images. In experiment 1, subjects had to decide which of two successively presented two-dot separations was wider. Over the range of interstimulus intervals employed (0 to 30 s), there was a linear relationship between interstimulus interval and spatial interval thresholds. In experiment 2 subjects' abilities to represent accurately more than one spatial interval at a time was investigated. Three dot pairs were presented, but only two pairs were to be compared, the third being completely irrelevant to the task. This manipulation doubled thresholds (relative to a two-dot-pair control condition), whether or not subjects were obliged to attend to the irrelevant dots. Overall, the results suggest that mental representations of spatial information may be temporally durable, but only in the absence of extraneous stimuli. The latter not only disrupt memory for spatial information, but appear to have obligatory access to it.

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