Spatial localization: tests of a two-process model

Adam, Jos J.; Paas, Fred; Ekering, J.; Loon, Editha M. van

doi:10.1007/bf00230657

Cited by 21 publications

(22 citation statements)

References 27 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Since we have no eye movement data, we hope to conduct future experiment to test the hypothesis directly. The second finding is partially at variance with the report of Adam, Paas, Ekering, and van Loon (1995) that accuracy decreases with the increase of target distances. This is true for brief targets, however, not justified for long duration target.…”

Section: Discussioncontrasting

confidence: 66%

Accuracy and Precision of Spatial Localization With and Without Saccadic Eye Movements: A Test of Two-Process Model

Uddin

Ninose

Nakamizo

2004

An International Journal of Psychological Sciences

View full text Add to dashboard Cite

and Sachio NAKAMIZO 1) 1) Kyushu University, JapanWe tested the two-process model of spatial localization (Adam, Ketelaars, Kingma, & Hoek, 1993) by measuring accuracy and precision of localization performance in three stimulus conditions: (i) no-saccade -observers were to maintain gaze on the fixation mark while target appeared for 1 s, (ii) saccade to on-target -they had to quickly saccade to and fixate on target remaining on for 1 s, and (iii) saccade to offtarget -they had to quickly saccade to the target appeared for 150 ms. Observers' task was to adjust position of a mouse cursor manually so that its position corresponds to the perceived position of the target. Results with six observers are consistent with the model suggesting localization performance to be mediated by memory-guided saccade for brief target and visually guided saccade for long duration target. The results further suggest that the memory-guided saccade provides relatively less accurate and precise information for localization and is a function of target eccentricity.Key words: spatial localization, two-process model, memory-guided saccade, visually guided saccade Adam, Ketelaars, Kingma, and Hoek (1993) reported on the time course and accuracy of spatial localization in which they demonstrated that localization performance showed an initial steep rise during the first 50 ms of stimulus duration followed by a gradual rise after 50 ms, reaching maximal performance at about 300 ms. They interpreted these two localization performance functions by the two-process model, which states that the two systems, namely the attention system for the initial steep rise and the eye movement system for the subsequent gradual rise, operate sequentially.The two process-model was supported by Adam et al. (1993) in which localization

show abstract

Section: Discussioncontrasting

confidence: 66%

Accuracy and Precision of Spatial Localization With and Without Saccadic Eye Movements: A Test of Two-Process Model

Uddin

Ninose

Nakamizo

2004

An International Journal of Psychological Sciences

View full text Add to dashboard Cite

show abstract

“…Inthe present context, it is important to note that these foveal mislocalizations were observed mainly with briefly presented stimuli-that is, with stimuli displayed only for a few vertical retraces of a monitor. In a pointing or cursor adjustment task, errors in localization are reduced or absent when presentation times are increased (Adam, Ketelaars, Kingma, & Hoek, 1993;Adam, Paas, Ekering, & van Loon, 1995). A comparable finding can be observed in measures of the accuracy of saccades' landing positions with respect to targets in the periphery.…”

mentioning

confidence: 87%

Relative mislocalization of briefly presented stimuli in the retinal periphery

Müsseler

Heijden

Mahmud

et al. 1999

Perception & Psychophysics

View full text Add to dashboard Cite

We studied the ability to localize flashed stimuli, using a relative judgment task. Whenobservers are asked to localize the peripheral position of a probe with respect to the midposition of a spatially extended comparison stimulus, they tend to judge the probe as being more toward the periphery than is the midposition of the comparison stimulus. We report seven experiments in which this novel phenomenon was explored. They reveal that the mislocalization occurs only when the probe and the comparison stimulus are presented in succession, independent of whether the probe or the comparison stimulus comes first (Experiment 1).The size of the mislocalization is dependent on the stimulus onset asynchrony (Experiment 2) and on the eccentricity of presentation (Experiment 3). In addition, the illusion also occurs in an absolute judgment task, which links mislocalization with the general tendency to judge peripherally presented stimuli as being more foveal than they actually are (Experiment 4). The last three experiments reveal that relative mislocalization is affected by the amount of spatial extension of the comparison stimulus (Experiment 5) and by its structure (Experiments 6 and 7). This pattern of results allows us to evaluate possible explanations of the illusion and to relate it to comparable tendencies observed in eye movement behavior. It is concluded that the system in charge of the guidance of saccadic eye movements is also the system that provides the metric in perceived visual space.The visual system processes the location of an object as soon as it appears in the visual field. Spatial acuity, measured with various standard methods, is accepted as being of very high precision. It increases from 5 min of arc at 10 0 retinal periphery to better than I min of arc in the fovea. This extremely high acuity is measured with tasks in which the relative position oftwo spatial features is determined (Badcock & Westheimer, 1985;Westheimer, 1981). However, these tasks assess acuity with long-presented, stationary targets with high contrastthus, under optimal viewing conditions. They require only local comparisons of simultaneously presented spatial features, which may not be the best indicators for direct absolute localizations (for an overview, see Skavenski, 1990).We thank Bruce Bridgeman, Asher Cohen, David Rose, and Steven Yantis for helpful comments and suggestions regarding a previous draft of the paper, Birgitt ABfalgand Sonja Stork for carrying out the experiments, and Marina von Bernhardi and Heidi John for stylistic suggestions. Correspondence concerning this article should be sent to 1. Miisseler,

show abstract

“…The ®rst component represented an initial steep rise in localization performance during the ®rst 50 ms of stimulus duration. The second component represented a gradual rise in localization performance as a function of increasing stimulus duration from 100 ms onwards, ®nishing with maximal performance at about 300 ms. 1 Adam et al (1993Adam et al ( , 1995 interpreted these two localization performance functions as re¯ecting the sequential operation of the attention system and the eye movement system. Hence, they postulated a two-process model according to which localization performance is mediated by two consecutive processes.…”

Section: Introductionmentioning

confidence: 99%

“…The main purpose of the present study was to gain insight in the act of object localization. Speci®cally, we sought to examine the recently proposed two-process model of localization performance (Adam, Ketelaars, Kingma, & Hoek, 1993;Adam, Paas, Ekering, & van Loon, 1995), according to which a shift of attention, providing coarse location information, is followed by a saccadic eye movement, providing ®ne location information.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Effects of spatial and symbolic precues on localization performance

Adam

Huys

Loon

et al. 2000

Psychological Research

Self Cite

View full text Add to dashboard Cite

One of the fundamental properties of spatial vision is the ability to localize objects in space. According to a recent proposal, accurate localization performance involves the operation of two systems: the attention system and the eye movement system. Upon stimulus presentation, attention is shifted to the target area: this provides coarse location information. Subsequently, a saccadic eye movement is executed: this provides fine location information. In this study we tested predictions derived from this model concerning the effects of precue information on localization performance. In a series of five experiments we manipulated duration of precue (71, 400, and 1,000 ms) and type of precue (spatial versus symbolic). Results showed that very short duration (i.e., 71 ms) spatial precues improved localization performance whereas very short duration symbolic precues did not. In contrast, the 1,000 ms duration precue condition showed similar amounts of precuing benefit for the spatial and symbolic precues. This pattern of differential precuing effects corroborated the two-process model of localization performance.

show abstract

Spatial localization: tests of a two-process model

Cited by 21 publications

References 27 publications

Accuracy and Precision of Spatial Localization With and Without Saccadic Eye Movements: A Test of Two-Process Model

Accuracy and Precision of Spatial Localization With and Without Saccadic Eye Movements: A Test of Two-Process Model

Relative mislocalization of briefly presented stimuli in the retinal periphery

Effects of spatial and symbolic precues on localization performance

Contact Info

Product

Resources

About