Accurate report is the standard behavioural index for consciousness in humans (Seth, Baars and Edelman, 2005, p. 119). When you go to bed and you want to know if your partner is still awake, you probably ask (quietly) “Are you sleeping?”. This is, of course, a very rough method. In clinical settings however, we still use -only slightly- more elaborate methods like the “Glasgow Coma Scale” (GCS).
The GCS is the most common scoring system used to describe the level of consciousness in a person following traumatic brain injury. Three aspects of behaviour are independently measured: motor responsiveness, verbal performance, and eye opening; see figure 1 for an example. On YouTube, you can find an entire GCS-channel with demonstration videos as how to administer the test. The procedure however, is not very reliable and apparently does not score much better than simple, unstructured clinical evaluation. For example, when two groups of emergency physicians administered the test to the same patient, the obtained total score was only in 38% of the cases the same (Green, 2011, p. 427). The original 14-point scale was revised in 1976 by adding an item, resulting in a total of maximal 15 points. Embarrassingly, Wiese (2003) observed that -almost a quarter of a century later- about 1 hospital out of 4 still uses the old 14 point scale, without realising that the other hospitals use the revised scale.
Figure 1. Glasgow Coma Scale: example chart from Teasdale & Jennett (1974), p. 83.
But what if a person cannot easily communicate, for example because he or she is paralysed? Locked-in syndrome is a condition in which a patient is aware and awake but cannot move or communicate verbally due to complete or nearly complete paralysis of all voluntary muscles in the body, with sometimes the exception of the eyes. How can you communicate with this person (see for example the video of Tony Nicklinson from 07:25″ on).
A highly controversial method called “facilitated communication” is sometimes used. This technique has been developed by Rosemary Crossley (current director of the Anne McDonald centre, Australia) in 1977 as part of her practical work for a Diploma of Education (Crossley, 1997, p. 138ff). Facilitated communication is, according to her, “an assistive communication technique in which a partner makes physical contact with a communication aid user to help overcome motor or emotional problems, such as low muscle tone or lack of confidence. It differs from co-active movement in that the direction of the movement is determined by the aid user, who is responsible for the content of the message.” (Crossley, 1997, p. 284). In other words, a second person (the facilitator) supports the hand or arm of the impaired individual who uses a kind of keyboard to communicate.
The controversy, of course, is about the question who really operates the keyboard: the aid user (patient) or the facilitator? Let’s take a look at the famous case of the Belgian Rom Houben. Rom was a young, healthy and bright person until, in 1983 at the age of 20, he was involved in a terrible car accident. As a result, he entered a state of coma, followed by more than 20 years of vegetative state (check the following video for in depth information about coma and vegetative state). In 2006 the team around dr. Laureys (University of Liège) started a study in which they re-examined 103 patients with severe brain injuries and concluded that 41% of the patients with the diagnosis “Vegetative State” were misdiagnosed. The team used the JFK Coma Recovery Scale (CSS-R); a similar but improved scale, compared to the Glasgow Coma Scale. Among the misdiagnosed patients was Rom Houben. The international magazine “Der Spiegel” covered the study.
The man [Rom Houben] who became lost to his surroundings now lives in an attractive nursing home in Zolder, a town in northwest Belgium. He is still almost completely paralyzed, but he is capable of a small amount of movement in his right hand, which he uses to communicate. With the help of a speech therapist, who stands behind him and supports his hand, Houben can now write on an on-screen keyboard. His finger rattles across the screen again, as he writes: “I will never forget the day they discovered me, the day of my second birth.”(Der Spiegel, 11/25/2009)
The article in Der Spiegel was picked up by the international press and Rom Houben soon appeared on TV channels all over the world, including AP, CNN, BBC, AVRO, RTL, CBS, TF1, TV1 and in countless newspapers and magazines. It is instructive to watch how fast the news spread and how similar the coverages were, with each program adding a little more detail and/or exaggeration.
http://www.youtube.com/watch?v=MX7i2inMoJk
Very soon, serious doubts concerning the facilitated communication were articulated e.g. by James Randi who asked for additional tests. After some initial resistance of the involved parties (family, nursing home and other organisations), these additional tests were admitted but unfortunately, Dr. Laureys had to conclude that Rom couldn’t communicate after all. These tests were advised by SKEPP, an independent organisation of skeptical people. When the facilitator for example didn’t know the questions, the answers of Rom were all completely wrong. It is informative to observe how little this new fact had made it in the press or how some, for example Dr Nancy, made the switch from believer to skeptic. Take a look at the two coverages of her highly popular show with only one week between: Nov, 23 and Nov, 30, 2010. This disaster could have easily be avoided if the proper tests were used right away. Already in 1983, this was suggested by the excellent Frontline documentary “Prisoners of Silence“.
Humans and some animals can recognize themselves in a mirror. This ability has been taken as a demonstration of self-consciousness and provides us with another “indirect” measure of consciousness. Mirror recognition is measured by the so called “Rouge test”, first described by G.G. Gallup in 1970 and tried on chimpanzees.
“In an attempt to add direct experimental support to the idea of self-recognition of the reflected [mirror] images, animals were anesthetized … With the animal unconsciousness, the uppermost portion of the eyebrow ridge and the top half of the opposite ear were then marked with a red alcohol-soluble … Four hours after having been marked, each animal was then directly observed for 30 minutes to determine the number of times any marked portion of the skin was touched spontaneously. The mirror was then reintroduced for a test of self-recognition at a distance of 0,6 m from the front of the cage, and behavior was monitored from behind the wall for an additional 30 minutes …” (Gallup, 1970, p. 86-87)
As you can see in figure 2, the animals touched the marked area significantly more after the test (marking) than before, indicating that they recognize themselves in the mirror. The test has subsequently been adapted for use with children by Amsterdam (1972).
“The results [with children] indicate the following age-related sequence of behavior before the mirror: the first prolonged and repeated reaction of an infant to his mirror image is that of a sociable “playmate” from about 6 through 12 months of age. In the second year of life wariness and withdrawal appeared; self-admiring and embarrassed behavior accompanied those avoidance behaviors starting at 14 months, and was shown by 75% of the subjects after 20 months of age. During the last part of the second year of life, from 20 to 24 months of age, 65% of the subjects demonstrated recognition of their mirror images.” (Amsterdam, 1972, p. 297).
The following video shows the proper administration of the test with children. It is part of the excellent BBC documentary “The secret you“, a quest for consciousness. Start watching at 06:30 – 09:05″. You can also see an interview with G. Gallup about his chimpanzees study (10:15 – 12:30″).
No matter, how intuitively the Rouge-test may seem, it is also not without reservations. Broesch et al. (2011) found very different success-rates in different countries for a simplified recognition test. In the US 88% of children passed the test by age 5, in Canada it was 77%, Saint Lucia (58%), Kenya (2%), Fiji (0%); see table 1, p. 1024 and results experiment 1 for Kenya). It is hard to believe that children from different cultures have different levels of self-awareness. The mirror-test also succeeded with other animals, e.g. elephants (Plotnik et al., 2006) but also in machines. A robot named Nico may soon pass the Rouge-test (Hart & Scassellati, 2012). Also, in 1981, a team around Skinner has already demonstrated that a pigeon could learn through operant conditioning to locate a spot on its body which it could only see in a mirror (Epstein et al., 1980).[Ref]Epstein, R., Lanza, R. P., Skinner, B. F., & others. (1981). Self-awareness in the pigeon. Science, 212(4495), 695–696. [extended description with pictures and movies at Lafayette][/ref]
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