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Egocentric Direction and Position Perceptions are Dissociable Based on Only Static Lane Edge Information.

Nakashima R, Iwai R, Ueda S, Kumada T - Front Psychol (2015)

Bottom Line: Experiment 1 examined the effect of the "uprightness factor" using normal and inverted road images.Experiment 2 examined the effect of the "central vision factor" using normal and transposed road images where the upper half of the normal image was presented under the lower half.Experiment 3 aimed to replicate the results of Experiments 1 and 2.

View Article: PubMed Central - PubMed

Affiliation: RIKEN Brain Science Institute-TOYOTA Collaboration Center, RIKEN Wako, Japan.

ABSTRACT
When observers perceive several objects in a space, at the same time, they should effectively perceive their own position as a viewpoint. However, little is known about observers' percepts of their own spatial location based on the visual scene information viewed from them. Previous studies indicate that two distinct visual spatial processes exist in the locomotion situation: the egocentric position perception and egocentric direction perception. Those studies examined such perceptions in information rich visual environments where much dynamic and static visual information was available. This study examined these two perceptions in information of impoverished environments, including only static lane edge information (i.e., limited information). We investigated the visual factors associated with static lane edge information that may affect these perceptions. Especially, we examined the effects of the two factors on egocentric direction and position perceptions. One is the "uprightness factor" that "far" visual information is seen at upper location than "near" visual information. The other is the "central vision factor" that observers usually look at "far" visual information using central vision (i.e., foveal vision) whereas 'near' visual information using peripheral vision. Experiment 1 examined the effect of the "uprightness factor" using normal and inverted road images. Experiment 2 examined the effect of the "central vision factor" using normal and transposed road images where the upper half of the normal image was presented under the lower half. Experiment 3 aimed to replicate the results of Experiments 1 and 2. Results showed that egocentric direction perception is interfered with image inversion or image transposition, whereas egocentric position perception is robust against these image transformations. That is, both "uprightness" and "central vision" factors are important for egocentric direction perception, but not for egocentric position perception. Therefore, the two visual spatial perceptions about observers' own viewpoints are fundamentally dissociable.

No MeSH data available.


Related in: MedlinePlus

Experimental sequence of a trial. In both tasks, two road images were sequentially presented for 250 ms with an intervening blank display (900 ms). Participants were instructed to judge which image was viewed straight in the front direction detection task, and to judge which image was viewed from the center of the lane in the center position detection task.
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Figure 2: Experimental sequence of a trial. In both tasks, two road images were sequentially presented for 250 ms with an intervening blank display (900 ms). Participants were instructed to judge which image was viewed straight in the front direction detection task, and to judge which image was viewed from the center of the lane in the center position detection task.

Mentions: Participants were seated on the chair whose position was fixed in front of the display in a dark room. Their head was fixed by a forehead and chin rest. The head horizontal position was the same as the position of the center of the display, in order to judge their actual egocentric direction and position correctly based on the road landscape. At the beginning of each trial, a fixation cross was presented and the participants were instructed to press the “5” key to start the trial when they were ready. During a trial, participants were told to gaze at the location (i.e., to look straight ahead) and not to move their eyes. They were instructed to look the picture planes as if they saw a road landscape through a windshield of a car. That is, they understood that they could not see themselves in the picture in this experiment. After their keypress, the fixation cross was visible for 100 ms and then it was replaced by a blank display presented for 500 ms. Then, two road images (each 250 ms) were presented sequentially, separated by a blank screen for 900 ms (Figure 2). After the presentation of the road images, a response display was presented until participants provided their responses. In the response display, the phrase “1st or 2nd?” was displayed, indicating that if observers judged the 1st image to be the correct answer, they should press the left-key (“4”), or otherwise the right-key (“6”). The correct answer was the front viewing direction image in the front direction detection task, and the center viewing position image in the center position detection task.


Egocentric Direction and Position Perceptions are Dissociable Based on Only Static Lane Edge Information.

Nakashima R, Iwai R, Ueda S, Kumada T - Front Psychol (2015)

Experimental sequence of a trial. In both tasks, two road images were sequentially presented for 250 ms with an intervening blank display (900 ms). Participants were instructed to judge which image was viewed straight in the front direction detection task, and to judge which image was viewed from the center of the lane in the center position detection task.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4663249&req=5

Figure 2: Experimental sequence of a trial. In both tasks, two road images were sequentially presented for 250 ms with an intervening blank display (900 ms). Participants were instructed to judge which image was viewed straight in the front direction detection task, and to judge which image was viewed from the center of the lane in the center position detection task.
Mentions: Participants were seated on the chair whose position was fixed in front of the display in a dark room. Their head was fixed by a forehead and chin rest. The head horizontal position was the same as the position of the center of the display, in order to judge their actual egocentric direction and position correctly based on the road landscape. At the beginning of each trial, a fixation cross was presented and the participants were instructed to press the “5” key to start the trial when they were ready. During a trial, participants were told to gaze at the location (i.e., to look straight ahead) and not to move their eyes. They were instructed to look the picture planes as if they saw a road landscape through a windshield of a car. That is, they understood that they could not see themselves in the picture in this experiment. After their keypress, the fixation cross was visible for 100 ms and then it was replaced by a blank display presented for 500 ms. Then, two road images (each 250 ms) were presented sequentially, separated by a blank screen for 900 ms (Figure 2). After the presentation of the road images, a response display was presented until participants provided their responses. In the response display, the phrase “1st or 2nd?” was displayed, indicating that if observers judged the 1st image to be the correct answer, they should press the left-key (“4”), or otherwise the right-key (“6”). The correct answer was the front viewing direction image in the front direction detection task, and the center viewing position image in the center position detection task.

Bottom Line: Experiment 1 examined the effect of the "uprightness factor" using normal and inverted road images.Experiment 2 examined the effect of the "central vision factor" using normal and transposed road images where the upper half of the normal image was presented under the lower half.Experiment 3 aimed to replicate the results of Experiments 1 and 2.

View Article: PubMed Central - PubMed

Affiliation: RIKEN Brain Science Institute-TOYOTA Collaboration Center, RIKEN Wako, Japan.

ABSTRACT
When observers perceive several objects in a space, at the same time, they should effectively perceive their own position as a viewpoint. However, little is known about observers' percepts of their own spatial location based on the visual scene information viewed from them. Previous studies indicate that two distinct visual spatial processes exist in the locomotion situation: the egocentric position perception and egocentric direction perception. Those studies examined such perceptions in information rich visual environments where much dynamic and static visual information was available. This study examined these two perceptions in information of impoverished environments, including only static lane edge information (i.e., limited information). We investigated the visual factors associated with static lane edge information that may affect these perceptions. Especially, we examined the effects of the two factors on egocentric direction and position perceptions. One is the "uprightness factor" that "far" visual information is seen at upper location than "near" visual information. The other is the "central vision factor" that observers usually look at "far" visual information using central vision (i.e., foveal vision) whereas 'near' visual information using peripheral vision. Experiment 1 examined the effect of the "uprightness factor" using normal and inverted road images. Experiment 2 examined the effect of the "central vision factor" using normal and transposed road images where the upper half of the normal image was presented under the lower half. Experiment 3 aimed to replicate the results of Experiments 1 and 2. Results showed that egocentric direction perception is interfered with image inversion or image transposition, whereas egocentric position perception is robust against these image transformations. That is, both "uprightness" and "central vision" factors are important for egocentric direction perception, but not for egocentric position perception. Therefore, the two visual spatial perceptions about observers' own viewpoints are fundamentally dissociable.

No MeSH data available.


Related in: MedlinePlus