Name: measuring sensitivity to viewpoint change with and without stereoscopic cues
Uploaded: 2013-12-04T18:30:00
Description: Watch this Scientific Journal Video about Measuring Sensitivity to Viewpoint Change with and without Stereoscopic Cues at JoVE.com

This research was supported by the Australian Research council. ARC Grant # DP110101511 given to JB; National Sciences and Engineering Research Council, NSERC of Canada Grant # RGPIN121713-11 given to FK ; ARC grant # DP130102580 and DP110104553 to DRB.

1. Prescreening
<ol>
	<li>Prior to testing, obtain written and informed consent from each participant.</li>
	<li>Ask the subject if they have normal or corrected-to-normal acuity (i.e. glasses).</li>
	<li>Verify the stereo acuity of the participant using a simple handheld stereo test.</li>
</ol>
2. Achieving Binocular Fusion in the Stereoscope
<ol>
	<li>Seat the participant at the desk in front of the mirror stereoscope and adjust the height of their chair for comfort.</li>
	<li>Turn ...

<ol>
	<li>Bennett, D. J., Vuong, Q. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+stereo+advantage+in+generalizing+over+changes+in+viewpoint+on+object+recognition+tasks.">A stereo advantage in generalizing over changes in viewpoint on object recognition tasks.</a> Percep. Psychophys. 68, 1082-1093 (2006).</li><li>Bulthoff, H. H., Edelman, S. Y., Tarr, M. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=How+are+three-dimensional+objects+represented+in+the+brain?.">How are three-dimensional objects represented in the brain?.</a> Cereb. Cortex. 5, 247-260 (1995).</li><li>Burke, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Combining+disparate+views+of+objects:+Viewpoint+costs+are+reduced+by+stereopsis.">Combining disparate views of objects: Viewpoint costs are reduced by stereopsis.</a> Vis. Cogn. 12, 705-719 (2005).</li><li>Burke, D., Taubert, J., Higman, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Are+face+representations+viewpoint+dependent?+A+stereo+advantage+for+generalising+across+different+views+of+faces.">Are face representations viewpoint dependent? A stereo advantage for generalising across different views of faces.</a> Vis. Res. 47, 2164-2169 (2007).</li><li>Edelman, S., Bulthoff, H. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Orientation+dependence+in+the+recognition+of+familiar+and+novel+views+of+three-dimensional+objects.">Orientation dependence in the recognition of familiar and novel views of three-dimensional objects.</a> Vis. Res. 32, 2385-2400 (1992).</li><li>Lim Lee, Y., Saunders, J. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Stereo+improves+3D+shape+discrimination+even+when+rich+monocular+shape+cues+are+available.">Stereo improves 3D shape discrimination even when rich monocular shape cues are available.</a> J. Vis. 11, (2011).</li><li>Parr, L. A., Siebert, E., Taubert, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Effect+of+familiarity+and+viewpoint+on+face+recognition+in+chimpanzees.">Effect of familiarity and viewpoint on face recognition in chimpanzees.</a> Perception. 40, 863-872 (2011).</li><li>Bell, J., Dickinson, J. E., Badcock, D. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Radial+frequency+adaptation+suggests+polar-based+coding+of+local+shape+cues.">Radial frequency adaptation suggests polar-based coding of local shape cues.</a> Vis. Res. 48, 2293-2301 (2008).</li><li>Wade, N. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=On+the+late+invention+of+the+stereoscope.">On the late invention of the stereoscope.</a> Perception. 16, 785-818 (1987).</li><li>Bell, J., Kanji, J., Kingdom, F. A. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Discrimination+of+rotated-in-depth+curves+is+facilitated+by+stereoscopic+cues,+but+curvature+is+not+tuned+for+stereoscopic+rotation-in-depth.">Discrimination of rotated-in-depth curves is facilitated by stereoscopic cues, but curvature is not tuned for stereoscopic rotation-in-depth.</a> Vis. Res. 77, 14-20 (2013).</li><li>Regan, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Human Perception of Objects. , (2000).</li><li>Howard, I. P., Rogers, B. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Binocular Vision and Stereopsis. , (1995).</li><li>Kingdom, F. A. A., Prins, N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Psychophysics: A Practical Introduction. , (2010).</li><li>Kingdom, F. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Color+brings+relief+to+human+vision.">Color brings relief to human vision.</a> Nat. Neurosci. 6, 641-644 (2003).</li><li>Ustinova, K. I., Perkins, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Gaze+and+viewing+angle+influence+visual+stabilization+of+upright+posture.">Gaze and viewing angle influence visual stabilization of upright posture.</a> Brain Behav. 1, 19-25 (1002).</li><li>Shieh, K. -. K., Lee, D. -. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Preferred+viewing+distance+and+screen+angle+of+electronic+paper+displays.">Preferred viewing distance and screen angle of electronic paper displays.</a> Appl. Ergon. 38, 601-608 (2007).</li></ol>

The methods discussed in this communication can be used by any researcher seeking to address questions related to discrimination and/or recognition of viewpoint rotated objects. Importantly, the method of perspective projection is not limited to the stimuli demonstrated here; instead it can be applied to a wide range of experimental stimuli, from lines to pictures of complex objects. Our introduction describes ways to apply this transformation using custom software, or library software such as MATLAB.
<p class="jove_...

Many studies have shown that the speed and accuracy of object recognition is compromised by a change in viewpoint1-7. For example, face recognition is best when the face is viewed in the fronto-parallel plane, i.e. &#34;front on&#34;, and declines systematically as the face is rotated in depth away from the fronto-parallel plane. Changes in viewpoint can occur either when the observer, or the viewed object, moves. Importantly, the viewpoint cost is often reduced by the introduction of stereoscopic cues to the observer1-4,6,8. It is, however, important to distinguish between the rotation of 3D and planar objects. The former may reveal new textures or structural information under rotation while this does not occur with planar objects. In this communication we discuss a method for simulating the appearance of planar shapes and objects that have been subject to rotation-in-depth, or RID. We describe an apparatus for turning the two-dimensional projection of a RID image into a vivid 3D (three-dimensional) percept of RID that is based on the Wheatstone mirror stereoscope9. Finally, we report a psychophysical method for determining whether stereoscopic (3D) cues influence our sensitivity to viewpoint change. Movie 1 demonstrates how the appearance of a shape is altered by a viewpoint change/RID.
Simulating a Viewpoint Change
When an object is subject to RID it does not of course physically change in identity or shape. However from the observer&#8217;s viewpoint, the shape does change. For instance, if you hold a sheet of paper directly in front of you in landscape view, the image of the paper in your eye, termed the retinal image, is a horizontal rectangle. If you then rotate the paper around its central vertical axis, the retinal image becomes foreshortened along the horizontal (see Figure 1 for a demonstration). Ultimately, if you rotate the paper through 90&#176; the retinal image is a thin strip the thickness of the paper. Thus the largest change to the image of the sheet of paper that has been subject to RID is a horizontal compression of its shape. A smaller change gradient of change occurs in the vertical extent with the image being taller for the nearest edge unchanged at the axis of rotation and shorter for the farther edge.
A RID can be simulated by appropriate transformation of images using software packages or by writing one&#8217;s own code8,10. Readers wishing to know more about RID can consult relevant texts and websites concerned with viewpoint transformations, or learn about built-in functions in the image processing software of packages such as those listed in our Materials. However, when transforming an image of a stimulus on a screen to represent a particular angle of RID there is an additional consideration: which type of projection to use, orthographic or perspective? When we view a scene, nearby objects produce larger retinal images than farther away objects. For a 2D (two-dimensional) object that is subject to RID this means that the far side is compressed more than the near side, as Figure 1 illustrates (see in particular the bottom right figure which has a RID of 60&#176;). The magnitude of the compression asymmetry is dependent upon the size of the object being subject to RID, and on our distance from it. Perspective projection incorporates this compression asymmetry whereas orthographic projection simply ignores it by assigning the same dimensions to the near and far sides of the RID object. Since an observer viewing a planar object rotate will be presented with this asymmetry we will use perspective projection here. Another advantage of our method is that the projection takes into account viewing distance from observer to screen. We have previously used our RID method to simulate viewpoint rotated shapes in both 2D perspective projection and in 3D8,10.
Simulating a 3D Viewpoint Change
In order to simulate stereoscopic RID one needs to present slightly different images to the left and right eyes. This difference between the two images is known as binocular disparity11, and is a function of both viewing distance and between-eye separation, specifically the inter-pupillary distance. Returning to the example of our sheet of paper in landscape view, if we rotate the piece of paper around the vertical center, clockwise by 45&#176; (so the left edge is receding), each eye&#8217;s view of the paper is slightly different. The image projected onto the left eye is slightly less than 45&#176; rotation while the image projected onto the right eye is slightly more than 45&#176; rotation (see Figure 2 for an illustration - observers who can free fuse the top two images will perceive a RID in 3D). If the appropriate RID angles are presented separately to the left and right eyes (the stereo condition) they will produce a disparity gradient and the observer is likely to report a vivid impression of a 3D RID. However if identical images, representing a 45&#176; rotation from the central viewing point, are presented to both eyes (the nonstereo condition) the observer will see a 2D representation of the RID stimuli. An established method for presenting separate images to the left and right eyes using a single monitor is to use a modification of the mirror stereoscope originally developed by Sir Charles Wheatstone in the mid 19th century12 &#8211; see Figure&#160;3. When the two stereo-half-images are positioned at corresponding locations in each eye&#8217;s view, they can be binocularly fused to produce a 3D percept (see Howard and Rogers12 for an extensive review of stereo methods and limitations).
By combining a simulated viewpoint change with stereoscopic presentation we can determine, for example, the role that stereoscopic cues play in our ability to detect changes in viewpoint. The demonstration results below reveal that when the size of a planar object, in this case a curved contour, is known or familiar to the observer, the change in the 2D width of the curve (sometimes termed its sag) is used to detect the change in RID, i.e. viewpoint (see Bell et al.10 for the full manuscript on this effect). Below we describe in detail a psychophysical method for measuring sensitivity to RID change for 2D- and 3D-defined planar shapes.

<table border="0" cellpadding="0" cellspacing="0" width="775">
	<colgroup>
		<col />
		<col />
		<col />
		<col />
	</colgroup>
	<tbody>
		<tr height="63">
			<td height="63" style="height:63px;width:216px;">Stereo testing</td>
			<td style="width:127px;">http://www.stereooptical.com/products/stereotests</td>
			<td style="width:152px;">Titmus stereofly test</td>
			<td style="width:280px;">Handheld testing devices</td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:216px;">Prebuilt stereo devices</td>
			<td style="width:127px;">http://www.stereoaids.com.au</td>
			<td style="width:152px;">prebuilt stereoscopes</td>
			<td>Suitable for desktop and laptop computers</td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:216px;">Mirror stereoscope</td>
			<td style="width:127px;">Custom made; or, Edmundoptics</td>
			<td style="width:152px;">8 mirror stereoscope</td>
			<td>www.edmundoptics.com</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Graphics card</td>
			<td style="width:127px;">NVidia</td>
			<td style="width:152px;"></td>
			<td>NVidia or ATI recommended</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Experimental control software</td>
			<td style="width:127px;">MATLAB</td>
			<td style="width:152px;"></td>
			<td>MATLAB, Python, C++, Visual Basic recommended</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Experimental control software</td>
			<td style="width:127px;">Psychtoolbox.org</td>
			<td style="width:152px;">Psychtoolbox</td>
			<td>Free to download but requires MATLAB</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Statistical software</td>
			<td style="width:127px;">Graphpad</td>
			<td style="width:152px;">Prism V5</td>
			<td>http://www.graphpad.com/</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Statistical software</td>
			<td style="width:127px;">Palamedes</td>
			<td style="width:152px;">Psychophysics guide</td>
			<td>http://www.palamedestoolbox.org</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">3D Projection documentation</td>
			<td style="width:127px;">Wikipedia</td>
			<td style="width:152px;"></td>
			<td>http://en.wikipedia.org/wiki/3D_projection</td>
		</tr>
	</tbody>
</table>

measuring sensitivity to viewpoint change with and without stereoscopic cues

The speed and accuracy of object recognition is compromised by a change in viewpoint; demonstrating that human observers are sensitive to this transformation. Here we discuss a novel method for simulating the appearance of an object that has undergone a rotation-in-depth, and include an exposition of the differences between perspective and orthographic projections. Next we describe a method by which human sensitivity to rotation-in-depth can be measured. Finally we discuss an apparatus for creating a vivid percept of a 3-dimensional rotation-in-depth; the Wheatstone Eight Mirror Stereoscope. By doing so, we reveal a means by which to evaluate the role of stereoscopic cues in the discrimination of viewpoint rotated shapes and objects.

Figure 4 plots example results obtained from such an experiment. The y-axis in each figure describes the proportion of times that the test pattern was chosen as having a greater RID. Rather than plotting the absolute number of times this occurred, this is given as a proportion. The x-axis describes the physical RID of the test pattern; remembering that here, the reference pattern was held at a constant 45&#176; RID. The data points represent the proportion of times that the observer chose the test curve ...

Watch this Scientific Journal Video about Measuring Sensitivity to Viewpoint Change with and without Stereoscopic Cues at JoVE.com

Measuring Sensitivity to Viewpoint Change with and without Stereoscopic Cues

We discuss a novel method forviewpoint-rotation of visual stimuli, and demonstrate using a mirror stereoscopethe three-dimensional percept of rotation-in-depth. The technique can be used to investigate the role of stereoscopic cues in encoding viewpoint-rotated figures.

Измерение чувствительности к точке зрения изменению с учетом и без Stereoscopic сцен

The speed and accuracy of object recognition is compromised by a change in viewpoint; demonstrating that human observers are sensitive to this ...

Research

JoVE Journal

Behavior

A Method for Investigating Age-related Differences in the Functional Connectivity of Cognitive Control Networks Associated with Dimensional Change Card Sort Performance

Метод исследования, связанные с возрастом различия в функциональной связности когнитивный контроль сети, связанной с Изменение размеров карты Сортировать Performance

The ability to adjust behavior to sudden changes in the environment develops gradually in childhood and adolescence. For example, in the Dimensional ...

Uncovering Beat Deafness: Detecting Rhythm Disorders with Synchronized Finger Tapping and Perceptual Timing Tasks

Раскрытие Удара Глухота: Обнаружение Нарушения ритма с синхронизацией палец нажатие и перцептивных синхронизации задач

A set of behavioral tasks for assessing perceptual and sensorimotor timing abilities in the general population (i.e., non-musicians) is presented here ...

Assessment of Murine Exercise Endurance Without the Use of a Shock Grid: An Alternative to Forced Exercise

Оценка мышиной упражнений на выносливость без применения ударной сетке: альтернатива принудительной упражнения

Using laboratory mouse models, the molecular pathways responsible for the metabolic benefits of endurance exercise are beginning to be defined. The most ...

A Treatment Package without Escape Extinction to Address Food Selectivity

Лечение Пакет без побег вымирания обеспечения продовольственной Селективность

Feeding difficulties and feeding disorders are a commonly occurring problem for young children, particularly children with developmental delays including ...

A Method to Test the Effect of Environmental Cues on Mating Behavior in Drosophila melanogaster

A Method to Test the Effect of Environmental Cues on Mating Behavior in Drosophila melanogaster

Метод проверки влияния экологических сигналов на поведение спаривания в<em&gt; Drosophila melanogaster</em

An individual's sexual drive is influenced by genotype, experience and environmental conditions. How these factors interact to modulate sexual behaviors ...

A Method for Investigating Change Blindness in Pigeons (Columba Livia)

A Method for Investigating Change Blindness in Pigeons Columba Livia

Метод для изучения изменения слепота в голуби (Columba Livia)

Change blindness is a phenomenon of visual attention, whereby changes to a visual display go unnoticed under certain specific circumstances. While many ...

Using Clicker Training and Social Observation to Teach Rats to Voluntarily Change Cages

Использование кликер подготовки и социального наблюдения научить крыс добровольно изменить клетки

Cage cleaning is a routinely performed husbandry procedure and is known to induce stress in laboratory rats. As stress can have a negative impact on ...

Modified Blood Collection from Tail Veins of Non-anesthetized Mice with a Vacuum Blood Collection System and Eyeglass Magnifier

Коллекция модифицированных крови из вен хвост-наркоз мышей с системой сбора механотронное крови и линзы лупы

Blood sample collection is the basis of experimental animal research. It is of importance to obtain adequate blood samples for various research purposes. ...

Assessing the Influence of Personality on Sensitivity to Magnetic Fields in Zebrafish

Оценка влияния личности на чувствительность к магнитным полям в данио рерио

To orient themselves in their environment, animals integrate a wide array of external cues, which interact with several internal factors, such as ...

Measuring Biophysical and Psychological Stress Levels Following Visitation to Three Locations with Differing Levels of Nature

Измерение уровня биофизического и психологического стресса после посещения трех мест с различными уровнями природы

Visitation to natural environments has been linked to psychological stress reduction. Although most stress-related research has relied on self-report ...