SkeptiCamp Phoenix 2013

In January, Arizona State University hosted the 2nd SkeptiCamp Phoenix event. I live-streamed video of the proceedings here.  The raw footage of each session is contained in the links below.

You can view video from Session 1 here:
You can view video from Session 2 here:
You can view video from Session 3 here:
You can view video from Session 4 here:

Tim Farley (@krelnik) kindly indexed these videos on here:

New Blogging Venture: ""

Have I fallen off the face of the earth?  To look at this blog, you would think so.  Unfortunately for some, I'm still alive and kicking, with lots of new research in the works and lots of opinions that need expressing in a public forum!  Although I quite enjoyed blogging here at Grand Delusions, I have moved my efforts to a new location on the web.  Along with my colleagues Rob Teszka and Katy Inglis, both psychological researchers with an interest in magic, I am blogging at  I encourage you to direct your browsers over to the new location and share in the fun.  There's lots of exciting new content and ideas in the hopper!

Friday Magic Showcase: Farrell Dillon

In April, I had the pleasure of performing alongside a group of Los Angeles magicians at the "Magic & the Brain"  event held at LA's Skirball Cultural Center.  One of the delightful magicians I was introduced to was Farrell Dillon, a funny and supremely talented performer.  According to his website:
Farrell is a rare honors graduate of the Chavez Studio of Magic, the most prestigious magic school in the world. Through this course Farrell was taught the methods and techniques of the world's master magicians. Farrell has a unique style that creates a perfect blend of magic, comedy, skill and illusion.

This week, thanks to, I came across a video created for Sunkist where Farrell employs magic and juggling to spread the "good word" of Sunkist mandarin oranges.  I wish all commercial productions were this entertaining!

Neuromagic 2011


Earlier this month, I had the pleasure of participating in the first ever conference on the interface of magic and neuroscience, Neuromagic 2011, on the secluded Spanish island of San Simón.  San Simón was the treasure trove that funded Captain Nemo’s adventures in Jules Verne’s classic fiction tale, 20,000 Leagues Under The Sea. The island has a dark history. Once home to the Templar Knights, pirates, a political prison, quarantined sanitarium, and concentration camp, the beautiful island has now been recast, after almost a decade of renovations by the government of the Galician autonomy of Spain (Xunta Galacia), to serve as a center for philosophy, art, culture, and science. And now, magic.

The list of attendees was a "who's who" in the worlds of magic and the neuroscience and psychology of deception and illusion.  Stephen Macknik and Susana Martinez-Conde, authors of the recent book Sleights of Mind, organized the event and spearheaded the difficult task of generating a common language to facilitate communication between the two represented fields. For my part, I expanded on some arguments recently presented in a paper in the journal Perception, wherein I highlighted a set of low-level visual processes which seem to provide the foundations on which many magical illusions are built.  (I previously blogged about one of these phenomena here.)

Additional scientists included Drs Peter Tse of Dartmouth College, Petter Johansson of University College London, Lars Hall of the University of Lund, Paul Zak of Claremont Graduate University, and Luis Martinez Otero of the Alicante Institute of Neuroscience. The magician attendees included James Randi, DJ Grothe (JREF president), Luis Piedrahita, Kiko Pastur, Max Maven, Eric Mead, Jamy Ian Swiss, and Miguel Angel Gea.

The talks and workshops jump-started discussions about how emotions interact with attention and awareness, how we are misdirected by performers, how magicians create the feeling of mystery and awe, and much more. Humor, logic and logical fallacies, empathy, faked moves, decision making, the nature of belief, and many other facets of human cognition are brought into play by magicians and mentalists, using techniques distilled from normal human behavior, so that they rarely fail to succeed. Fully, 13 formal collaborative projects were launched among the participants as a direct result of the gathering, to more completely study magic in the brain.

Here is a short video (much of which is in Spanish) that came out of the event, including many beautiful images of the island. Enjoy!

Magical Expertise & the Kinematics of Deception

In 1896, Joseph Jastrow, founder of the renowned psychology department at the University of Wisconsin, invited two of the most illustrious figures in the history of magic into his laboratory: Alexander Herrmann (also known as "Herrmann the Great") and Harry Kellar. The two were unlikely collaborators. At the time, Herrmann was the world's best-known magician, and Kellar was arguably his greatest competitor. Their "paper wars" were infamous. If both were performing in the same town, they made a point of posting their own advertisements over those of their competitor. This resulted in layers upon layers of posters, as each tried to out-do the other.

Jastrow solicited the help of these magic icons because he was interested in examining the effect of magical expertise on perception and attention. It was reasoned that these men, who were masters in the manipulation of attention and perception, may have developed more highly-sensitive perceptual faculties by virtue of their expertise. To this end, Jastrow led Herrmann and Kellar through a battery of different tests of tactile sensitivity, motor fluency, and visual perception. Although the magicians evinced substantial individual differences on most of these tasks (with Herrmann demonstrating a flippant , arrogant attitude in his performance, which led to low accuracy and slow reaction time in many instances), Jastrow was forced to conclude that, in general, the conjurers' faculties did not differ from those of the average participant.

Recently, a new study has been released by Cristina Cavina-Pratesi, Gustav Kuhn, and colleagues (2011) taking an approach similar to Jastrow's. Magicians regularly produce actions that are meant to simulate other actions. For example, they may pretend to transfer a coin from one hand to the other while really retaining it in the original hand. Pantomimed actions of this type have been studied before (although not with magicians), and they consistently produce kinematic patterns that vary substantially from those of purposeful actions. Cavina-Pratesi and colleagues were interested to know whether magicians, who have honed their pantomime skills, show these same biases in pantomimed behavior.
To test this, they first asked a group of magicians and non-magicians to grasp and move a block of wood from one location to another or to pantomime the same action. While participants completed the task, researchers tracked the kinematics of each type of grasp. Importantly, just before the grasp (or
Figure 1: From Cavina-Pratesi
et al. (2011)
pantomimed grasp) took place, experimenters blocked the participants' vision using a pair of liquid crystal shutter glasses. This emulated a common strategy employed by magicians, who often shift their attention away from a piece of sleight of hand in the hope that viewers will also attend elsewhere. Thus, participants were grasping or pantomiming based on a recent memory of the visual object rather than actual visual feedback from the object. 

The researchers found that magicians did not demonstrate many of the standard kinematic biases usually observed during pantomimed grasping. Specifically, people usually have a reduced grip aperture when pantomiming a grasp. Otherwise stated, they don't open their fingers as wide when initiating a pantomimed grasp as they do when initiating an actual grasp. This bias was not apparent in the kinematics of the magicians, while it did appear for the non-magicians. Thus, magicians' pantomimed grasps are quite similar to their actual grasps. This was even the case when they were asked to grasp the block of wood in an unusual way (see Figure 1d). 

In a follow-up experiment, Cavina-Pratesi et al. showed that these biases do emerge when magicians are asked to simply imagine the object in the absence of visual stimulation. From this, they concluded that magicians do not have improved visualization abilities compared to non-magicians. Instead, they are more adept in the use of environmental information (the distal image of the wood block) to guide their pantomimed action. In their words, "[Magicians] have learnt that the best way to fake an action is by performing it 'for real'" (p. 4).

Further support for this position has been provided by Natter and Phillips (2008) who showed that experienced magicians are attuned to and able to simulate subtle muscular and temporal shifts that coincide with the transfer of a coin from one hand to the other (as simulated in the classic French Drop sleight), while novice magicians are relatively insensitive to these characteristics of physical manipulation. Indeed, the best way to learn sleight of hand is to first increase one's awareness of the kinematics involved in the action being simulated.


Cavina-Pratesi, C., Kuhn, G., Ietswaart, M., & Milner, A. D. (2011). The magic grasp: Motor expertise in deception. PLoS ONE, 6, e16568. doi: 10.1371/journal.pone.0016568. [link]

Jastrow, J. (1896). Psychological notes upon sleight-of-hand experts. Science, 3, 685-689.

Natter, M., & Phillips, F. (2008). The french drop sleight: Deceptive biological motion [Abstract]. Journal of Vision, 8, 1052. doi:10.1167/8.6.1052. [link]

"Sleights of Mind"

You should probably buy this book. Why? Two reasons:

  1. It's the first book dedicated to discussing the neuroscience of magic.
  2. I'm featured prominently within its pages.

While is processing your order, I encourage you to watch this segment from the PBS Horizon program.

Do newborns imitate?

Recently, a group of scientists including prominent mirror neuron researcher, Vittorio Gallese, published an article purporting to demonstrate social interaction between identical twin fetuses in the uterus (at a time in their development before they have even the most basic reflexes). While their conclusions were highly dubious, their study is not actually the focus of this blog entry. Instead, I want to address something that they bring up in the fourth sentence of their introductory remarks. Castiello et al. (2010) state that, "even hours after birth, newborns have been found to show preparedness for social interaction that, among other things, is expressed in their imitation of facial gestures" (p. 1).

It seems that nearly every researcher in the fields of embodiment and comparative psychology has accepted this idea, that neonates are wired to imitate, wholeheartedly, yet the evidence cited to support this position is surprisingly scant. Namely, researchers cite the iconic work of Meltzoff and Moore (1977) published in Science, which suggested that newborns are capable of imitating facial gestures. Specifically, it was suggested that infants were capable of imitating both tongue protrusions (TPs) and mouth opening (MO). You may have seen Figure 1 from Meltzoff and Moore (1977) in many textbooks.

In their primer on infant cognition, Moll and Tomasello (2010) interpreted this finding as evidence that, “infants had an innate understanding that other persons are ‘like me,’ which constitutes a critical basis for deeper intersubjective understanding later in life” (p. R873). Is this interpretation warranted, though?

A good amount of research has been carried out since Meltzoff and Moore’s initial publication, and much of it indicates that Meltzoff was way off base, yet this research has captured almost no attention. It’s been all but ignored by mirror neuron researchers who cite the Meltzoff work as if it is without question. I contend that Meltzoff’s work has been thoroughly debunked, and I’d like to briefly lay out some of the evidence here.

The first question is, can Meltzoff’s findings be relicated? The answer: not exactly. Anisfeld (1996) reviewed the literature on infant imitation, reporting that MO imitation (and other frequently investigated varieties of imitation) is rare while TP imitation is robust. See a problem yet? Infants only imitate one behavior? Awfully strange, considering that imitation of this one behavior serves no discernible evolutionary purpose. That leads to the second question: Why might an infant appear to be imitating this behavior?

The answer to this question is actually quite interesting. It’s important to note that TP imitation is relatively short-lived. Infants quit imitating tongue protrusions around the age of 2 or 3 months (Jacobson, 1979). Oddly enough, this decline happens to coincide with the development of reaching behaviors. Thus, up until this development, infants primarily interact with the world via their mouths. Might it be the case that TPs are simply the result of stimulation? Indeed, in a beautiful set of experiments, Jones (1996) showed that a blinking light (a completely non-social stimulus) elicited tongue protrusions (at least for infants who showed interest in the blinking light) and that infants were more attracted to faces with a protruding tongue than faces with an open mouth. This points to tongue protrusion as a result of stimulation, not imitation. Finally, she showed that the development of reaching behavior coincided with the decline of TP responses to interesting objects within the infants’ reach.

Thus, imitation of TPs is simply coincidental, and it is unlikely to be imitation, at all. Are we wired to imitate or do we learn to imitate? Given the first option’s foundation on grains of sand, I lean toward the second option.


Anisfeld, M. (1996). Only tongue protrusion modeling is matched by neonates. Developmental Review, 16, 149-161. [Link to Abstract]

Castiello, U., Becchio, C., Zoia, S., Nelini, C., Sartori, L., Blason, L., et al. (2010). Wired to be social: The ontogeny of human interaction. PLoS One, 5, e13199. [Link to Open Access Entry]

Jacobson, S. W. (1979). Matching behavior in the young infant. Child Development, 50, 425-430. [Link to PDF]

Jones, S. S. (1996). Imitation or exploration? Young infants' matching of adults' oral gestures. Child Development, 67, 1952-1969. [PDF]

Meltzoff, A. N., & Moore, M. K. (1977). Imitation of facial and manual gestures by human neonates. Science, 198, 75-78. [PDF]

Moll, H., & Tomasello, M. (2010). Infant cognition. Current Biology, 20, R872-R875. [Link to Abstract]

Let the Blogging Resume

I've neglected this blog for too long. I must come to my senses on this. Unfortunately, this semester is kicking me in the head, so there's no way for me to keep up with the blogging schedule I was able to establish over the summer. I'm planning to resume blogging, but with a reduced schedule...Possibly one or two posts per week. Thank you for your kind attention. I hope that you continue to drop by.