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Using a stick does not necessarily alter judged distances or reachability.

de Grave DD, Brenner E, Smeets JB - PLoS ONE (2011)

Bottom Line: Verbal judgments were given either in centimeters or in terms of whether the object would be reachable with the hand.No differences in verbal distance judgments or touching responses were found between the blocks in which the stick or the hand was used.Instead of finding out why the judged distance changes when using a tool, we found that using a stick does not necessarily alter judged distances or judgments about the reachability of objects.

View Article: PubMed Central - PubMed

Affiliation: Research Institute MOVE, Faculty of Human Movement Sciences, VU University, Amsterdam, The Netherlands. Denise-de.Grave@unilever.com

ABSTRACT

Background: It has been reported that participants judge an object to be closer after a stick has been used to touch it than after touching it with the hand. In this study we try to find out why this is so.

Methodology: We showed six participants a cylindrical object on a table. On separate trials (randomly intermixed) participants either estimated verbally how far the object is from their body or they touched a remembered location. Touching was done either with the hand or with a stick (in separate blocks). In three different sessions, participants touched either the object location or the location halfway to the object location. Verbal judgments were given either in centimeters or in terms of whether the object would be reachable with the hand. No differences in verbal distance judgments or touching responses were found between the blocks in which the stick or the hand was used.

Conclusion: Instead of finding out why the judged distance changes when using a tool, we found that using a stick does not necessarily alter judged distances or judgments about the reachability of objects.

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Related in: MedlinePlus

Top view of the experimental set-up for the three sessions.First participants are shown an object on the table. Then, depending on the session, they either estimate the distance of the object or determine whether the object is reachable with their hand. Estimation trials are randomly interleaved with touching trials. Whether touching is done with the hand or with the stick is blocked. Depending on the session, participants either touch the remembered location of the object or touch the location halfway between the object and the starting position.
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pone-0016697-g002: Top view of the experimental set-up for the three sessions.First participants are shown an object on the table. Then, depending on the session, they either estimate the distance of the object or determine whether the object is reachable with their hand. Estimation trials are randomly interleaved with touching trials. Whether touching is done with the hand or with the stick is blocked. Depending on the session, participants either touch the remembered location of the object or touch the location halfway between the object and the starting position.

Mentions: Participants sat in front of a rectangular table (160×80 cm) with their upper body against the table, which prevented them from bending over the table. Their body midline was aligned with a start position (figure 2). The start position was a small wooden block (2.5×2.5×2.5 cm) with its nearest edge 6 cm from the nearest edge of the table. The start position specified the location from which the distance to the stimulus object was to be estimated (session 1 and 2). The stimulus object consisted of a white plastic cylinder (diameter: 5 cm; height: 10 cm). The table-top was uniformly green to minimize landmarks that could influence distance judgments. The table was in a typically cluttered laboratory environment, but there were no objects in the space immediately surrounding the table. Each session contained two blocks of trials. In one block of trials participants used a wooden stick (length: 55 cm) to perform a touching task. A marker was attached to the distal end of the stick to track its movement with an Optotrak 3020 system (sampling rate 250 Hz, resolution 0.01 mm). In the other block of trials participants did not use the stick and a marker was attached to the nail of the participant's right index finger. Participants wore liquid crystal shutter glasses (Plato System; Translucent Technologies, Toronto, Ontario, Canada) so that we could control the time that the object was visible.


Using a stick does not necessarily alter judged distances or reachability.

de Grave DD, Brenner E, Smeets JB - PLoS ONE (2011)

Top view of the experimental set-up for the three sessions.First participants are shown an object on the table. Then, depending on the session, they either estimate the distance of the object or determine whether the object is reachable with their hand. Estimation trials are randomly interleaved with touching trials. Whether touching is done with the hand or with the stick is blocked. Depending on the session, participants either touch the remembered location of the object or touch the location halfway between the object and the starting position.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3044725&req=5

pone-0016697-g002: Top view of the experimental set-up for the three sessions.First participants are shown an object on the table. Then, depending on the session, they either estimate the distance of the object or determine whether the object is reachable with their hand. Estimation trials are randomly interleaved with touching trials. Whether touching is done with the hand or with the stick is blocked. Depending on the session, participants either touch the remembered location of the object or touch the location halfway between the object and the starting position.
Mentions: Participants sat in front of a rectangular table (160×80 cm) with their upper body against the table, which prevented them from bending over the table. Their body midline was aligned with a start position (figure 2). The start position was a small wooden block (2.5×2.5×2.5 cm) with its nearest edge 6 cm from the nearest edge of the table. The start position specified the location from which the distance to the stimulus object was to be estimated (session 1 and 2). The stimulus object consisted of a white plastic cylinder (diameter: 5 cm; height: 10 cm). The table-top was uniformly green to minimize landmarks that could influence distance judgments. The table was in a typically cluttered laboratory environment, but there were no objects in the space immediately surrounding the table. Each session contained two blocks of trials. In one block of trials participants used a wooden stick (length: 55 cm) to perform a touching task. A marker was attached to the distal end of the stick to track its movement with an Optotrak 3020 system (sampling rate 250 Hz, resolution 0.01 mm). In the other block of trials participants did not use the stick and a marker was attached to the nail of the participant's right index finger. Participants wore liquid crystal shutter glasses (Plato System; Translucent Technologies, Toronto, Ontario, Canada) so that we could control the time that the object was visible.

Bottom Line: Verbal judgments were given either in centimeters or in terms of whether the object would be reachable with the hand.No differences in verbal distance judgments or touching responses were found between the blocks in which the stick or the hand was used.Instead of finding out why the judged distance changes when using a tool, we found that using a stick does not necessarily alter judged distances or judgments about the reachability of objects.

View Article: PubMed Central - PubMed

Affiliation: Research Institute MOVE, Faculty of Human Movement Sciences, VU University, Amsterdam, The Netherlands. Denise-de.Grave@unilever.com

ABSTRACT

Background: It has been reported that participants judge an object to be closer after a stick has been used to touch it than after touching it with the hand. In this study we try to find out why this is so.

Methodology: We showed six participants a cylindrical object on a table. On separate trials (randomly intermixed) participants either estimated verbally how far the object is from their body or they touched a remembered location. Touching was done either with the hand or with a stick (in separate blocks). In three different sessions, participants touched either the object location or the location halfway to the object location. Verbal judgments were given either in centimeters or in terms of whether the object would be reachable with the hand. No differences in verbal distance judgments or touching responses were found between the blocks in which the stick or the hand was used.

Conclusion: Instead of finding out why the judged distance changes when using a tool, we found that using a stick does not necessarily alter judged distances or judgments about the reachability of objects.

Show MeSH
Related in: MedlinePlus