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Exocentric pointing in the visual field.

van Doorn A, Koenderink J, Wagemans J - Iperception (2013)

Bottom Line: Phenomenologically, such pointings show systematic deviations from veridicality of several degrees.The errors are very small in the vertical and horizontal directions, but appreciable in oblique directions.A general conclusion is that the visual field cannot be described in terms of one of the classical homogeneous spaces, or, alternatively, that the results from pointing involve mechanisms that come after geometry proper has been established.

View Article: PubMed Central - PubMed

Affiliation: Laboratory of Experimental Psychology, University of Leuven (KU Leuven), Tiensestraat 102 box 3711, B-3000 Leuven, Belgium; and Faculteit Sociale Wetenschappen, Psychologische Functieleer, Universiteit Utrecht, Heidelberglaan 2, 3584 CS Utrecht, The Netherlands; e-mail: andrea.vandoorn@telfort.nl.

ABSTRACT
"Exocentric pointing in the visual field" involves the setting of a pointer so as to visually point to a target, where both pointer and target are objects in the visual field. Phenomenologically, such pointings show systematic deviations from veridicality of several degrees. The errors are very small in the vertical and horizontal directions, but appreciable in oblique directions. The magnitude of the error is largely independent of the distance between pointer and target for stretches in the range 2-27°. A general conclusion is that the visual field cannot be described in terms of one of the classical homogeneous spaces, or, alternatively, that the results from pointing involve mechanisms that come after geometry proper has been established.

No MeSH data available.


Related in: MedlinePlus

Here the short (white points) and long (black points) stretches have been selected from the raw data. The results for the other participants look very similar.
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Figure 6: Here the short (white points) and long (black points) stretches have been selected from the raw data. The results for the other participants look very similar.

Mentions: It seems a priori likely that the deviation will depend on the stretch to be covered by the pointing, that is, the distance between the locations of target and pointer. In order to check this we divided the data in short, medium, and long stretches. Short stretches are defined as stretches shorter than the 25% quartile of all stretches, whereas long stretches are defined as stretches longer than the 75% quartile of all stretches. A comparison of the short and long stretches (this involves only one half of the data, of course) is shown in Figure 6 for participant AD.


Exocentric pointing in the visual field.

van Doorn A, Koenderink J, Wagemans J - Iperception (2013)

Here the short (white points) and long (black points) stretches have been selected from the raw data. The results for the other participants look very similar.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4129387&req=5

Figure 6: Here the short (white points) and long (black points) stretches have been selected from the raw data. The results for the other participants look very similar.
Mentions: It seems a priori likely that the deviation will depend on the stretch to be covered by the pointing, that is, the distance between the locations of target and pointer. In order to check this we divided the data in short, medium, and long stretches. Short stretches are defined as stretches shorter than the 25% quartile of all stretches, whereas long stretches are defined as stretches longer than the 75% quartile of all stretches. A comparison of the short and long stretches (this involves only one half of the data, of course) is shown in Figure 6 for participant AD.

Bottom Line: Phenomenologically, such pointings show systematic deviations from veridicality of several degrees.The errors are very small in the vertical and horizontal directions, but appreciable in oblique directions.A general conclusion is that the visual field cannot be described in terms of one of the classical homogeneous spaces, or, alternatively, that the results from pointing involve mechanisms that come after geometry proper has been established.

View Article: PubMed Central - PubMed

Affiliation: Laboratory of Experimental Psychology, University of Leuven (KU Leuven), Tiensestraat 102 box 3711, B-3000 Leuven, Belgium; and Faculteit Sociale Wetenschappen, Psychologische Functieleer, Universiteit Utrecht, Heidelberglaan 2, 3584 CS Utrecht, The Netherlands; e-mail: andrea.vandoorn@telfort.nl.

ABSTRACT
"Exocentric pointing in the visual field" involves the setting of a pointer so as to visually point to a target, where both pointer and target are objects in the visual field. Phenomenologically, such pointings show systematic deviations from veridicality of several degrees. The errors are very small in the vertical and horizontal directions, but appreciable in oblique directions. The magnitude of the error is largely independent of the distance between pointer and target for stretches in the range 2-27°. A general conclusion is that the visual field cannot be described in terms of one of the classical homogeneous spaces, or, alternatively, that the results from pointing involve mechanisms that come after geometry proper has been established.

No MeSH data available.


Related in: MedlinePlus