Name: investigating the 'uncatchable smile' in leonardo da vinci's la bella principessa: a comparison with the mona lisa and pollaiuolo's portrait of a girl
Uploaded: 2016-10-04T13:00:00
Description: Watch this Scientific Journal Video about Investigating the 'Uncatchable Smile' in Leonardo da Vinci's La Bella Principessa: A Comparison with the Mona Lisa and Pollaiuolo's Portrait of a Girl at JoVE

The Print Shop at Sheffield Hallam University is thanked for providing high quality reproductions of the portraits used in this study. Michael Pickard and Jonathan Dean are thanked for their valuable insights.

The protocol was approved by the Faculty Research Ethics Committee at Sheffield Hallam University for studies on human subjects.
1. Inter-observation Stage
<ol>
	<li>Identify how and why La Bella Principessa&#39;s expression appears ambiguous.
	<ol>
		<li>Display a good quality, frameless and exact sized foam backed digital copy of La Bella Principessa (33.2 cm in height x 23.8 cm in width) on an easel in diffuse lighting.</li>
		<li>Have four participants discuss the ambiguous expression in...

<ol>
	<li>Kemp, M., Cotte, P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> La Bella Principessa: The Story of the New Masterpiece by Leonardo da Vinci. , (2010).</li><li>Livingstone, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Is+it+warm?+Is+it+real?+Or+just+low+spatial+frequency.">Is it warm? Is it real? Or just low spatial frequency.</a> Science. 290 (5495), 1299 (2000).</li><li>Soranzo, A., Newberry, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+uncatchable+smile+in+Leonardo+da+Vinci's+La+Bella+Principessa+portrait.">The uncatchable smile in Leonardo da Vinci's La Bella Principessa portrait.</a> Vis.Res. 113, 78-86 (2015).</li><li>Silverman, P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Leonardo's Lost Princess. , (2012).</li><li>Kemp, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Leonardo. , (2011).</li><li>Kemp, M., Cotte, P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> La Bella Principessa. The Story of the New Masterpiece by Leonardo da Vinci. , (2010).</li><li>Bozzi, P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=L'interosservazione+come+metodo+per+la+fenomenologia+sperimentale+[Interobservation+as+a+method+for+experimental+phenomenology].">L'interosservazione come metodo per la fenomenologia sperimentale [Interobservation as a method for experimental phenomenology].</a> Giorn. It Psic. 5, 229-239 (1978).</li><li>Bozzi, P., Martinuzzi, L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Un+esperimento+di+interosservazione+[An+experiment+of+interobservation].">Un esperimento di interosservazione [An experiment of interobservation].</a> Riv. Psic. 74, 11-46 (1989).</li><li>Kubovy, M., Wilson, R. A., Keil, F. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Gestalt+Psychology.">Gestalt Psychology.</a> The MIT Encyclopedia of the Cognitive Sciences. , 346-349 (1999).</li><li>Harr&#233;, R., Secord, P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> The Explanation of Social Behaviour. , (1972).</li><li>Asch, S. E., Guetzkow, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Effects+of+group+pressure+on+the+modification+and+distortion+of+judgments.">Effects of group pressure on the modification and distortion of judgments.</a> Groups, Leadership and Men. , 177-190 (1951).</li><li>Setlur, V., Gooch, B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Is+that+a+smile?+Gaze+dependent+facial+expressions.">Is that a smile? Gaze dependent facial expressions.</a> NPAR 2004 Proceedings 3rd int. symp. on non-photorealistic animation and rendering. , 79-151 (2004).</li><li>Ekman, P., Friesen, W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Unmasking the face. A guide to recognizing emotions from facial cues. , (1975).</li><li>Latto, R., Russell-Duff, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=An+oblique+effect+in+the+selection+of+line+orientation+by+twentieth+century+painters.">An oblique effect in the selection of line orientation by twentieth century painters.</a> Emp stud. Arts. 20 (1), 49-60 (2002).</li><li>Glaser, B. G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Basics of Grounded Theory Analysis. , (1992).</li><li>Glaser, B. G., Strauss, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> The Discovery of Grounded Theory: Strategies for Qualitative Research. , (1967).</li><li>Strauss, A., Corbin, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Grounded+theory+research:+Procedures,+canons,+and+evaluative+criteria.">Grounded theory research: Procedures, canons, and evaluative criteria.</a> Qual. Soc. 13, 3-21 (1990).</li><li>Strauss, A., Corbin, 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> Grounded Theory in Practice. , (1997).</li><li>Kurtz, T. E., Arscott, J., Taggart, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Gold Edition Reference Guide for the True BASIC Language System. , (2010).</li><li>Z&#246;llner, F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Ueber+eine+neue+Art+von+Pseudoskopie+und+ihre+Beziehungen+zu+den+von+Plateau+und+Oppel+beschrieben+Bewegungs+phaenomenen.+[On+a+New+Kind+of+Pseudoskopics+and+its+Relationship+to+the+Motion+Phenomena+Described+by+Plateau+and+Oppel].">Ueber eine neue Art von Pseudoskopie und ihre Beziehungen zu den von Plateau und Oppel beschrieben Bewegungs phaenomenen. [On a New Kind of Pseudoskopics and its Relationship to the Motion Phenomena Described by Plateau and Oppel].</a> Annalen der Physik. 186, 500-525 (1860).</li><li>Hering, E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Beitr&#228;ge zur Physiologie. I. Zur Lehre vom Ortssinne der Netzhaut [Contributions to physiology I about the doctrines of local senses of the retina. , (1861).</li><li>Orbison, W. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+correction+of+an+omission+in+"Shape+as+a+function+of+the+vector+field".">The correction of an omission in "Shape as a function of the vector field".</a> Am J.l of Psyc. 52, 309 (1939).</li><li>Anstis, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+furrow+illusion:+Peripheral+motion+becomes+aligned+with+stationary+contours.">The furrow illusion: Peripheral motion becomes aligned with stationary contours.</a> J. of Vis. 12, 1-11 (2012).</li><li>Ito, H., Yang, X. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+short+line+segment+squirms+along+a+zigzag+line.">A short line segment squirms along a zigzag line.</a> i-Perc. 4, 141 (2013).</li><li>Ambadar, Z., Schooler, J. W., Cohn, J. F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Deciphering+the+Enigmatic+Face:+The+Importance+of+Facial+Dynamics+in+Interpreting+Subtle+Facial+Expressions.">Deciphering the Enigmatic Face: The Importance of Facial Dynamics in Interpreting Subtle Facial Expressions.</a> Am. Psych. Soc. 16 (5), 403-410 (2005).</li></ol>

The findings of the study conducted by Soranzo &#38; Newberry3 indicate that the ambiguity of the expression in Leonardo da Vinci&#39;s La Bella Principessa portrait is attributable to a visual illusion. A new mixed-methodology which combined three methods: Inter-observation, structured interviews, and psychophysical experiments was adopted. Firstly, the inter-observation method was used to shed some light on the &#39;ambiguity&#39; of the Princess&#39;s facial expression. This method which involves l...

This paper discusses the methodology used by Soranzo and Newberry3 to investigate the &#39;Uncatchable Smile&#39; illusion in Leonardo da Vinci&#39;s La Bella Principessa portrait. The overall goal of the methodology employed was to identify what makes the expression of the Princess ambiguous. The portrait shows the profile of a young woman identified as Bianca, the illegitimate daughter of Ludovico, who at around 13 years of age was to be married to a commander of the Duke&#39;s Milanese forces4. According to Kemp5, the portrait was commissioned by the Duke in honor of the celebration of her marriage in 1496. Kemp and Cotte6 noted that the expression of La Bella Principessa is ambiguous and &#34;subtle to an inexpressible degree&#34; (p.26), although the question remains as to what it is that triggers this ambiguity and whether this is similar to that perceived in Leonardo&#39;s Mona Lisa.
Soranzo and Newberry&#39;s3 study involved three stages which combined three different research methods. The rationale for using these different research methods was to conduct a research investigation that developed without prior beliefs, thus minimizing potential researcher bias. The first stage used the inter-observation method to investigate why the expression of the Princess is ambiguous; in the second, a structured interview was used to identify the psychological dimension underpinning the &#39;Uncatchable Smile&#39; illusion; and in the third stage experiments were conducted to test hypotheses formulated on the basis of the findings of the first two stages. Independent groups of participants took part in these three stages and the findings of each stage influenced the following stages. This is likely to have reduced researcher bias compared to if the researchers had determined the research questions themselves.
The advantages of combining different research methods over singular methods are as follows. First, the inter-observation stage enabled discussion to take place about where the ambiguity may have originated from (rather than the researchers imposing their own pre-determined view). Second, the interview stage enabled the identification of the psychological dimension to be investigated without imposing pre-defined categories. Third, the experimental stage enabled the perceptual change identified in the previous stages to be quantified in a controlled manner.
Inter-observation
As noted above, La Bella Principessa&#39;s expression is &#34;subtle to an inexpressible degree&#34;6. The first step of the research was to try to identify what it is about the portrait that makes the expression ambiguous. To do this, the inter-observation method posited by Paolo Bozzi and his colleagues7, 8 was conducted with three participants and the senior author. This method enables maximum information to be extracted from direct experience9 and involves looking together, discussing and mutually exchanging views. The first step of the research adhered to the guidelines provided by Bozzi who argued that observers should conjointly partake in the observational process in a natural environment (not in a laboratory); observers should be aware of the researcher&#39;s hypothesis (no hidden hypothesis); the instructions to participants should be broad and discussed together rather than providing strict instructions; the discussion should go beyond the first impression (for a discussion of the un-permeability of this method in relation to the so called &#34;conformity effect&#34; found by Asch11 see Bozzi7). According to Bozzi, the discussion should go beyond the first impression in order to explore all possible solutions. The conclusion is therefore reached through a process of &#34;negotiation&#34; between the participants and the researcher, and negotiation is the process through which a common account is determined10. Participants were presented with a copy of La Bella Principessa&#39;s portrait resting on an easel in diffuse lightning. General instructions were given; participants were requested to discuss the ambiguous expression of La Bella Principessa. In the negotiation stage, it became clear early on that the ambiguity in the Princess&#39;s expression, or the allure of the portrait, is triggered by a perceptual change. The Princess&#39;s expression is ambiguous because it is unstable; sometimes she looks happy and cheerful whilst at other times she looks melancholic and hostile. However, the conditions under which this change occurs were still not known. Further inspection and negotiation led to the unanimous conclusion that the change relates to the way the portrait is viewed: the Princess&#39;s expression appears to change when she is viewed from different distances. When the Princess is viewed from far away her mouth appears to take an upward direction, making her appear friendly and positive, but as soon as the portrait is approached, the Princess&#39;s mouth appears to take a downwards slant, making her look sad and unapproachable. In other words, it seems that the ambiguity in the Princess&#39;s expression is due to a visual illusion of direction, which depends on the viewing distance. Since spatial frequency changes with distance it was concluded that this change relates to spatial frequency.
The existence of a spatial frequency-dependent illusion of direction was also explored by using a blurred digital version of the portrait. A digital version of La Bella Principessa was presented on a computer screen and the level of blur was manipulated. The blurring process was essentially a convolution kernel of the pixel spreading type in which pixels take contributions from their surrounding pixels, while de-emphasizing contributions from the center12. In addition to appearing more cheerful and happy when viewed from a distance, La Bella Principessa also appeared more cheerful and happy when viewed as a blurred image. This supports the idea of a spatial frequency-dependent illusion. The concept of spatial frequency-dependent facial expression is supported by a wide understanding of how the human visual system is particularly sensitive to seeing and interpreting the subtleties of facial expression13, 14.
Structured Interviews
The results of the inter-observation stage led us to hypothesize that the Princess&#39;s expression is ambiguous because it is unstable and that this instability may be attributable to a spatial frequency-dependent perceptual change relating to the direction of the mouth. The assumption was that if there is a &#39;perceptual change&#39; which relates to the way the portrait is viewed, then there must be a controllable way to elicit one impression in the viewer over another (for example, the melancholic one rather than the cheerful one). The challenge was to find out how to control the viewer&#39;s impression of La Bella Principessa in order to generate one impression over the other. Before addressing this problem in a quantitative manner, structured interviews were conducted to determine the psychological dimension that best captures this perceptual change.
Four participants who had not taken part in the inter-observational stage of the study took part in a structured interview. Participants were shown an identical copy of La Bella Principessa&#39;s portrait resting on an easel in diffuse lighting. Participants were asked to describe the Princess&#39;s expression and to note any differences in the expression when viewed from close or further away. Interestingly, participants&#39; descriptions were not framed in terms of outward expressions such as &#39;smiling&#39; but more with the internal emotional state of the Princess. A Grounded Theory analysis15,16,17,18 of the descriptions was conducted and it was found that the most common words used to describe the Princess&#39;s expression were &#34;happiness&#34; and &#34;contentment&#34;. These findings suggested that the change in the Princess&#39;s expression might be better captured with the definition of a change in perceived &#34;contentment&#34;. Together, the inter-observational and structured interview stages informed the formulation of five hypotheses as follows: First, the viewer&#39;s distance from La Bella Principessa&#39;s portrait will influence their perception of her facial expression. Specifically, the ratings of contentment will be higher when the portraits are viewed from further away. Second, the portrait&#39;s level of blur will influence the perceived contentment of La Bella Principessa. Specifically, presenting digital versions of the portrait with an increased level of blur will lead to an increase in the viewer&#39;s perception of contentment. Third, the uncatchable smile illusion is mainly attributable to the mouth area of La Bella Principessa&#39;s portrait. Fourth, the perceived slant of La Bella Principessa&#39;s mouth will change when the distance of the portrait is manipulated. Specifically, the corner of the mouth will appear to take an upward turn when distance is increased. Fifth, the perceived slant of La Bella Principessa&#39;s mouth will change when a digital version of the portrait is presented with different levels of blur. Specifically, the corner of the mouth will appear to take an upward turn when the level of blur is increased.
Psychophysical Experiments
In the quantitative stage of the study, five psychophysical experiments were conducted to test the aforementioned hypotheses. In addition, since it was hypothesized that a similar effect would be observed for the Mona Lisa&#39;s expression, this portrait was also included in the investigation. Furthermore, to test whether the effect under investigation is specific to La Bella Principessa and the Mona Lisa or whether it may be general to all portraits of Leonardo&#39;s era, a control portrait was also used. This was the Portrait of a Girl painted around 1470 by Piero del Pollaiuolo. This was chosen as a suitable control for La Bella Principessa as the portrait is from the same period and there are similarities of size, presentation and appearance in the subject matter.

<table border="0" cellpadding="0" cellspacing="0" width="1531">
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		<tr height="19">
			<td height="19" style="height:19px;width:841px;">High quality same size reproductions of the following three portraits: The Mona Lisa and La Bella Principessa (Leonardo da Vinci) and Portrait of a Girl (Piero del Pollaiuolo)</td>
			<td style="width:691px;">The Print Shop - Sheffield Hallam University - Sheffield Hallam University, Howard Street, Sheffield, South Yorkshire S1 1WB, United Kingdom</td>
		</tr>
		<tr height="19">
			<td height="19" style="height:19px;">Easel for resting portraits on</td>
			<td>No particular brand needed</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Laptop computer with wireless mouse for experiments</td>
			<td>Lenovo</td>
		</tr>
		<tr height="20">
			<td height="40" rowspan="2" style="height:40px;">Programming software to write syntax to present the pictures in random order, record participant responses from the keyboard, and enable the measurement &#39;handle&#39; to be adjusted by participants</td>
			<td rowspan="2">True Basic software</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Image editing software</td>
			<td>Adobe Photoshop CC 2015</td>
		</tr>
	</tbody>
</table>

investigating the 'uncatchable smile' in leonardo da vinci's la bella principessa: a comparison with the mona lisa and pollaiuolo's portrait of a girl

This paper discusses how the &#39;Uncatchable Smile&#39; illusion in Leonardo da Vinci&#39;s La Bella Principessa portrait was discovered. Kemp and Cotte1 described the expression of the Princess as ambiguous and &#34;subtle to an inexpressible degree&#34;. A combination of three methods was used (inter-observation, structured interviews, and psychophysical experiments) to identify what may underlie this &#39;ambiguity&#39;. The inter-observation and the structured interview methods were firstly applied to generate experimental hypotheses that were successively tested by a series of psychophysical experiments. The combination of these research methods minimizes the impact of the researcher&#39;s beliefs and biases in the development of the research design. It emerged that the ambiguity in La Bella Principessa is triggered by a change in the perceived level of contentment in her facial expression and that this perceptual change is attributable to a visual illusion relating to her mouth. Moreover, it was found that a similar effect can be observed in the Mona Lisa. As the smile in La Bella Principessa disappears as soon as the viewer tries to &#39;catch it&#39;, we named this visual illusion the &#39;Uncatchable Smile&#39;. The elusive quality of the Mona Lisa&#39;s smile2 is probably why the portrait is so famous, and so the existence of a similar ambiguity in a portrait painted by Leonardo prior to the Mona Lisa is even more interesting.

From the negotiation process of the Inter-observation stage it was ascertained that the ambiguity in the Princess&#39;s expression might be due to a visual illusion of direction which depends on the viewing distance. Since spatial frequency changes with distance it was concluded that this change relates to spatial frequency. A Grounded Theory analysis of the descriptions obtained in the Structured Interview stage was performed and it was found that observers tended to describe her change ...

Watch this Scientific Journal Video about Investigating the 'Uncatchable Smile' in Leonardo da Vinci's La Bella Principessa: A Comparison with the Mona Lisa and Pollaiuolo's Portrait of a Girl at JoVE

Investigating the &#039;Uncatchable Smile&#039; in Leonardo da Vinci&#039;s La Bella Principessa: A Comparison with the Mona Lisa and Pollaiuolo&#039;s Portrait of a Girl

This paper discusses the methodology used to reveal the &#39;Uncatchable Smile&#39; illusion in Leonardo da Vinci&#39;s La Bella Principessa portrait. A combination of three methods was used (inter-observation, structured interviews, and psychophysical experiments), which led to an investigation that shaped itself without prior beliefs, thus reducing potential researcher bias.

Investigating the 'Uncatchable Smile' in Leonardo da Vinci's La Bella Principessa: A Comparison with the Mona Lisa and Pollaiuolo's Portrait of a Girl

This paper discusses how the &#39;Uncatchable Smile&#39; illusion in Leonardo da Vinci&#39;s La Bella Principessa portrait was discovered. Kemp and Cotte1 ...

The overall goal of this experiment is to investigate the uncatchable smile in Leonardo da Vinci's La Bella Principessa and compare it with the Mona Lisa and a control portrait. This method of investigating multiple attributes can help identify what creates the ambiguity in the expression of La Bella Principessa and the Mona Lisa. The main advantage of using different research methods was to conduct a research investigation that developed without prior beliefs, thus minimizing potential research bias.In a well-lit room, begin by displaying La Bella Principessa's portrait in the center of an A1 paper pad that is resting on an easel. Ask the participant to describe the woman's expression and to note any differences in the participant's response as they view the portrait from close-up and from far away. Have the participant write down their observations on paper.To begin, place two markers on the floor in front of the easel, one 0.5 meters from the portrait for the close-up condition and the other eight meters from the portrait for the far condition. Depending on the experimental condition, display exact sized foam-backed digital copies of La Bella Principessa, the Mona Lisa, or the Portrait of a Girl at the center of an AI paper pad resting on the easel 1.80 meters from the floor. Ensure that the easel is placed under diffused lighting at the end of a long hallway with two doors that are 0.5 and eight meters from the portrait, respectively.Then cover the portrait with a sheet. As an extra precaution, for a participant assigned to the far condition, have them enter the corridor from the furthest door and stop at the marker furthest away from the portrait that they have been assigned to. Likewise, for a participant in the close condition, have them enter the corridor from the closest door and stop at the market closest to the portrait that they have been assigned to.Once the participant is at the marker, unveil the portrait and ensure that they are only able to see the portrait from the assigned marker. Finally, ask the participant to verbally rate the perceived contentment in the expression of the woman viewed in the assigned portrait on a scale of one to seven. Record the participant's response.Begin by creating a set of digital images for each of the three portraits with increasing levels of Gaussian blur in steps of one pixel per image. Next, seat a participant 50 centimeters away from either a normal computer monitor or a large screen, as in this case, in a well-illuminated room. Ask the participant to use the numeric keyboard to rate the perceived contentment in the expression of La Bella Principessa, Mona Lisa and the figure in Portrait of a Girl from one to seven.In order to establish the source of the illusory effect, use the same digital images of La Bella Principessa with different levels of Gaussian blur to create masked images. To do this, create a solid black rectangle mask of 0.3 by 0.6 centimeters and place it either over the mouth, over the eyes, or over both the mouth and eyes of the portrait. Finally, ask the participant to rate the perceived contentment of these masked La Bella Principessa images on a scale of one to seven.In a large room with diffused lighting, use a projector connected to a computer to display an exact sized digital version of La Bella Principessa onto a screen 1.80 meters from the floor. Place a wireless keyboard on top of the table 0.5 meters from the computer screen for the close condition and eight meters away from the screen for the far condition. Next, use programming software, to create a 0.9 centimeter long black hairline measurement handle on the computer screen.Place the hairline handle at the same level and four centimeters left of the mouth. Instruct the participant to use the minus and plus keys on the numeric keyboard to adjust the slant of the handle until it aligns with the perceived slant of the mouth of the woman in the portrait. Press the space bar to record the perceived mouth slant angle.For the final experiment, present eight versions of La Bella Principessa with different levels of blur in a random order on the screen. Finally, have the participant adjust the slant of the handle on each of the blurred images until it aligns with the perceived slant of the woman's mouth in the portrait. When La Bella Principessa and Mona Lisa were observed from a distance, their perceived contentment was significantly higher than when the portraits were viewed from close-up, whereas, there was no significant effect for Pollaiuolo's Portrait of a Girl.The level of blur affected the perceived contentment of La Bella Principessa and Mona Lisa, but did not affect Pollaiuolo's Portrait. Furthermore, the perceived contentment of La Bella Principessa increased with the level of blur in both the no mask and eye mask conditions. Finally, the perceived mouth slant of La Bella Principessa was perceived to take an upward slant when viewed from far away, but it was perceived to take a downward direction when observed from close-up.After watching this video, you should have a good understanding of how to investigate how the pieces eliciting ambiguous emotions through the combined use of three methods;inter-observations, structured interviews, and psycho-physical experiments. While attempting this procedure, it's important to remember to recruit different participants for each of the three different stages of this method. While in the inter-observation stage, participant can be familiar with the stimuli, it is important that participants in the experimental stage are naive to the hypotheses.After its development, this technique paved the way for researchers in art perception to explore different pieces of art.

investigating-uncatchable-smile-leonardo-da-vinci-s-la-bella

Research

JoVE Journal

Behavior

The Crossmodal Congruency Task as a Means to Obtain an Objective Behavioral Measure in the Rubber Hand Illusion Paradigm

The rubber hand illusion (RHI) is a popular experimental paradigm. Participants view touch on an artificial rubber hand while the participants' own hidden hand is touched. If the viewed and felt touches are given at the same time then this is sufficient to induce the compelling experience that the rubber hand is one's own hand. The RHI can be used to investigate exactly how the brain constructs distinct body representations for one's own body. Such representations are crucial for successful interactions with the external world. To obtain a subjective measure of the RHI, researchers typically ask participants to rate statements such as "I felt as if the rubber hand were my hand". Here we demonstrate how the crossmodal congruency task can be used to obtain an objective behavioral measure within this paradigm.
The variant of the crossmodal congruency task we employ involves the presentation of tactile targets and visual distractors. Targets and distractors are spatially congruent (i.e. same finger) on some trials and incongruent (i.e. different finger) on others. The difference in performance between incongruent and congruent trials - the crossmodal congruency effect (CCE) - indexes multisensory interactions. Importantly, the CCE is modulated both by viewing a hand as well as the synchrony of viewed and felt touch which are both crucial factors for the RHI.
The use of the crossmodal congruency task within the RHI paradigm has several advantages. It is a simple behavioral measure which can be repeated many times and which can be obtained during the illusion while participants view the artificial hand. Furthermore, this measure is not susceptible to observer and experimenter biases. The combination of the RHI paradigm with the crossmodal congruency task allows in particular for the investigation of multisensory processes which are critical for modulations of body representations as in the RHI.

We demonstrate how an objective measure can be employed in the widely employed rubber hand illusion paradigm. This measure is obtained by modifying the well-established crossmodal congruency task. This task allows the investigation of multisensory processes which are critical for modulations of body representations as in the rubber hand illusion.

The rubber hand illusion (RHI) is a popular experimental paradigm. Participants view touch on an artificial rubber hand while the participants' own hidden ...

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

The ability to adjust behavior to sudden changes in the environment develops gradually in childhood and adolescence. For example, in the Dimensional Change Card Sort task, participants switch from sorting cards one way, such as shape, to sorting them a different way, such as color. Adjusting behavior in this way exacts a small performance cost, or switch cost, such that responses are typically slower and more error-prone on switch trials in which the sorting rule changes as compared to repeat trials in which the sorting rule remains the same. The ability to flexibly adjust behavior is often said to develop gradually, in part because behavioral costs such as switch costs typically decrease with increasing age. Why aspects of higher-order cognition, such as behavioral flexibility, develop so gradually remains an open question. One hypothesis is that these changes occur in association with functional changes in broad-scale cognitive control networks. On this view, complex mental operations, such as switching, involve rapid interactions between several distributed brain regions, including those that update and maintain task rules, re-orient attention, and select behaviors. With development, functional connections between these regions strengthen, leading to faster and more efficient switching operations. The current video describes a method of testing this hypothesis through the collection and multivariate analysis of fMRI data from participants of different ages.

This video presents a method of examining age-related changes in functional connectivity of cognitive control networks engaged by targeted tasks/processes. The technique is based on multi-variate analysis of fMRI data.

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

A set of behavioral tasks for assessing perceptual and sensorimotor timing abilities in the general population (i.e., non-musicians) is presented here with the goal of uncovering rhythm disorders, such as beat deafness. Beat deafness is characterized by poor performance in perceiving durations in auditory rhythmic patterns or poor synchronization of movement with auditory rhythms (e.g., with musical beats). These tasks include the synchronization of finger tapping to the beat of simple and complex auditory stimuli and the detection of rhythmic irregularities (anisochrony detection task) embedded in the same stimuli. These tests, which are easy to administer, include an assessment of both perceptual and sensorimotor timing abilities under different conditions (e.g., beat rates and types of auditory material) and are based on the same auditory stimuli, ranging from a simple metronome to a complex musical excerpt. The analysis of synchronized tapping data is performed with circular statistics, which provide reliable measures of synchronization accuracy (e.g., the difference between the timing of the taps and the timing of the pacing stimuli) and consistency. Circular statistics on tapping data are particularly well-suited for detecting individual differences in the general population. Synchronized tapping and anisochrony detection are sensitive measures for identifying profiles of rhythm disorders and have been used with success to uncover cases of poor synchronization with spared perceptual timing. This systematic assessment of perceptual and sensorimotor timing can be extended to populations of patients with brain damage, neurodegenerative diseases (e.g., Parkinson&#8217;s disease), and developmental disorders (e.g., Attention Deficit Hyperactivity Disorder).

Behavioral tasks that allow for the assessment of perceptual and sensorimotor timing abilities in the general population (i.e., non-musicians) are presented. Synchronization of finger tapping to the beat of an auditory stimuli and detecting rhythmic irregularities provides a means of uncovering rhythm disorders.

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

The Modified Hole Board - Measuring Behavior, Cognition and Social Interaction in Mice and Rats

This protocol describes the modified hole board (mHB), which combines features from a traditional hole board and open field and is designed to measure multiple dimensions of unconditioned behavior in small laboratory mammals (e.g., mice, rats, tree shrews and small primates). This paradigm is a valuable alternative for the use of a behavioral test battery, since a broad behavioral spectrum of an animal&#8217;s behavioral profile can be investigated in one single test.
The apparatus consists of a box, representing the &#8216;protected&#8217; area, separated from a group compartment. A board, on which small cylinders are staggered in three lines, is placed in the center of the box, representing the &#8216;unprotected&#8217; area of the set-up. The cognitive abilities of the animals can be measured by baiting some cylinders on the board and measuring the working and reference memory. Other unconditioned behavior, such as activity-related-, anxiety-related- and social behavior, can be observed using this paradigm. Behavioral flexibility and the ability to habituate to a novel environment can additionally be observed by subjecting the animals to multiple trials in the mHB, revealing insight into the animals&#8217; adaptive capacities.
Due to testing order effects in a behavioral test battery, na&#239;ve animals should be used for each individual experiment. By testing multiple behavioral dimensions in a single paradigm and thereby circumventing this issue, the number of experimental animals used is reduced. Furthermore, by avoiding social isolation during testing and without the need to food deprive the animals, the mHB represents a behavioral test system, inducing if any, very low amount of stress.

This protocol describes the modified hole board, which is a behavioral test set-up that comprises the characteristics of an open field and a traditional hole board. This set-up enables the differential analysis of unconditioned behavior of small laboratory mammals as well as the analysis of cognitive abilities.

This protocol describes the modified hole board (mHB), which combines features from a traditional hole board and open field and is designed to measure ...

The Social Dimension of Stress: Experimental Manipulations of Social Support and Social Identity in the Trier Social Stress Test

In many situations humans are influenced by the behavior of other people and their relationships with them. For example, in stressful situations supportive behavior of other people as well as positive social relationships can act as powerful resources to cope with stress. In order to study the interplay between these variables, this protocol describes two effective experimental manipulations of social relationships and supportive behavior in the laboratory. In the present article, these two manipulations are implemented in the Trier Social Stress Test (TSST)&#8212;a standard stress induction paradigm in which participants are subjected to a simulated job interview. More precisely, we propose (a) a manipulation of the relationship between different protagonists in the TSST by making a shared social identity salient and (b) a manipulation of the behavior of the TSST-selection committee, which acts either supportively or unsupportively. These two experimental manipulations are designed in a modular fashion and can be applied independently of each other but can also be combined. Moreover, these two manipulations can also be integrated into other stress protocols and into other standardized social interactions such as trust games, negotiation tasks, or other group tasks.

Previous research on the social dimension of stress has focused on two important variables: social identity and social support. This protocol introduces an effective experimental manipulation of these two social variables and describes their implementation in a standard stress induction paradigm (Trier Social Stress Test).

In many situations humans are influenced by the behavior of other people and their relationships with them. For example, in stressful situations ...

A Pressure Injection System for Investigating the Neuropharmacology of Information Processing in Awake Behaving Macaque Monkey Cortex

The top-down modulation of feed-forward cortical information processing is functionally important for many cognitive processes, including the modulation of sensory information processing by attention. However, little is known about which neurotransmitter systems are involved in such modulations. A practical way to address this question is to combine single-cell recording with local and temporary neuropharmacological manipulation in a suitable animal model. Here we demonstrate a technique combining acute single-cell recordings with the injection of neuropharmacological agents in the direct vicinity of the recording electrode. The video shows the preparation of the pressure injection/recording system, including preparation of the substance to be injected. We show a rhesus monkey performing a visual attention task and the procedure of single-unit recording with block-wise pharmacological manipulations.

Here, we show the pressure injection of neuropharmacological substances during single-cell recording in an awake, behaving macaque monkey. This procedure allows pharmacological manipulation in the direct vicinity of a cortical recording site.

The top-down modulation of feed-forward cortical information processing is functionally important for many cognitive processes, including the modulation ...

Investigating Motor Skill Learning Processes with a Robotic Manipulandum

Skilled reaching tasks are commonly used in studies of motor skill learning and motor function under healthy and pathological conditions, but can be time-intensive and ambiguous to quantify beyond simple success rates. Here, we describe the training procedure for reach-and-pull tasks with ETH Pattus, a robotic platform for automated forelimb reaching training that records pulling and hand rotation movements in rats. Kinematic quantification of the performed pulling attempts reveals the presence of distinct temporal profiles of movement parameters such as pulling velocity, spatial variability of the pulling trajectory, deviation from midline, as well as pulling success. We show how minor adjustments in the training paradigm result in alterations in these parameters, revealing their relation to task difficulty, general motor function or skilled task execution. Combined with electrophysiological, pharmacological and optogenetic techniques, this paradigm can be used to explore the mechanisms underlying motor learning and memory formation, as well as loss and recovery of function (e.g. after stroke).

A paradigm is presented for training and analysis of an automated skilled reaching task in rats. Analysis of pulling attempts reveals distinct subprocesses of motor learning.

Skilled reaching tasks are commonly used in studies of motor skill learning and motor function under healthy and pathological conditions, but can be ...

A Behavioral Assay for Investigating the Role of Spatial Memory During Instinctive Defense in Mice

Evolution has selected a repertoire of defensive behaviors that are essential for survival across all animal species. These behaviors are often stereotyped actions elicited in response to innately aversive sensory stimuli, but their success requires enough flexibility for adapting to different spatial environments, which can change rapidly. Here, we describe a behavioral assay to evaluate the influence of learned spatial knowledge on defensive behaviors in mice. We have adapted the widely used Barnes maze spatial memory assay to investigate how mice navigate to a shelter during escape responses to innately aversive sensory stimuli in a novel environment, and how they adapt to acute changes in the environment. This new assay is an ethological paradigm that does not require training and exploits the natural exploration patterns and navigation strategies in mice. We propose that the set of protocols described here are a powerful means of studying goal-directed behaviors and stimulus-triggered navigation, which should be of interest to both the fields of instinctive behaviors and spatial memory.

This protocol describes a behavioral assay, based on the Barnes maze test, to study how instinctive defensive actions are modified by the knowledge of spatial environment.

Evolution has selected a repertoire of defensive behaviors that are essential for survival across all animal species. These behaviors are often ...

Methods of Pairing and Pair Maintenance of New Zealand White Rabbits (Oryctolagus Cuniculus) Via Behavioral Ethogram, Monitoring, and Interventions

New Zealand White (NZW) laboratory rabbits (Oryctolagus cuniculus), as well as their ancestors the European Rabbit, are a social species that exhibit numerous benefits to being housed accordingly. Although these rabbits are innately gregarious, certain behaviors can still arise when kept in captivity, which if left unchecked, can confound research results or lead to wounding, which in extreme cases can be severe. To prevent these issues, there must be a well-structured plan for the monitoring and maintenance of paired laboratory rabbits. The purpose of this protocol is to present effective procedures for establishing newly paired NZW rabbits as well as methods for successful maintenance. Multiple methods have been tested for the creation of newly paired female rabbits from the vendor, but the most efficacious technique emphasizes capitalizing on the stress bonding from transport, urine marking, pairing in a neutral cage with no forced sharing of resources and a system of monitoring and intervention. To determine the best method of housing paired rabbits in a standard caging environment, data were collected to generate a behavioral ethogram. Behaviors were then quantified as positive, neutral or negative and were tracked across the lifespan of the pair to determine which behaviors indicated pair success or failure. With the newfound knowledge of socially housed laboratory NZW rabbit behavior, enrichment intervention was applied to alleviate aggression and prevent wounding, thus resulting in a higher percentage of successful pairs. Through several years of trialing different pairing methods, the development of the ethogram and the resulting enrichment interventions, understanding of the highly complex social constructs that dominate pair housed rabbit behavior has dramatically increased and allowed for the provision of more species-specific care and increased standards of welfare.

Methods of Pairing and Pair Maintenance of New Zealand White Rabbits Oryctolagus Cuniculus Via Behavioral Ethogram, Monitoring, and Interventions

Though European rabbits are a social species, socially housing them can be challenging. Therefore, there must be a thorough understanding of behaviors and social structures of pair-housed laboratory rabbits. Here we present a protocol to identify pairing methods, species-typical hierarchy establishment behaviors and behaviors that warrant appropriate intervention.

New Zealand White (NZW) laboratory rabbits (Oryctolagus cuniculus), as well as their ancestors the European Rabbit, are a social species that exhibit ...

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

Visitation to natural environments has been linked to psychological stress reduction. Although most stress-related research has relied on self-report formats, a growing number of studies now incorporate biological stress-related hormones and catalysts, such as cortisol and &#945;-amylase, to measure levels of stress. Presented here is a protocol to examine the effects on levels of biophysical and psychological stress following visitation to three different locations with differing levels of nature. Biophysical and self-reported psychological stress levels are measured immediately upon entering the selected locations and just prior to the visitors leaving the site. Using a &#34;drool&#34;&#160;method, the biophysical measure consists of 1-2 mL samples of saliva provided by study subjects upon entry to one of three study locations. As prescribed by extant literature, the saliva is collected within a 45 minute time frame following the end of the visitor&#8217;s engagement at the location. Following saliva collection, the samples are labeled and transported to a biological lab. Cortisol is the biophysical variable of interest in this study and measured using an ELISA process with a TECAN plate reader. To measure self-reported stress, the Perceived Stress Questionnaire (PSQ), which reports levels of worry, tension, joy, and perceived demands. Data are collected at all three sites in the late afternoon through early evening. When compared across all three settings, stress levels, as measured by both the biological markers and self-reports, are significantly lower after visitation to the most natural setting.

The purpose of this paper is to identify changes in stress levels after visitation to three different settings and to describe the methods used in identifying stress levels based on measures of salivary cortisol, &#945;-amylase, and a psychological self-report instrument.&#160;

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