Philosophy of Illusions

Thurston_magician_posterResearchers from Edinburgh University have claimed to show that stage illusionists and magicians rely on the phenomenon of “change-blindness” for their tricks. Although we may feel that we normally have visual awareness of an entire stable scene all at once, experiments show that subjects can be surprisingly bad at noticing large-scale changes that occur right before their eyes. In fact, our eyes “saccade” around a scene, very rapidly shifting a very narrow point of focus. Changes that occur during such shifts and outside the narrow range of focus will not be noticed by the subject.

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Why choose the tiramisu?

Attr. Markus Mitterauer

A highly influential experiment, conducted over 30 years ago, presented an array of indistinguishable stockings to subjects who were then asked to pick the one they found most appealing. Overwhelmingly, the subjects preferred the stockings on their right. When asked about the reasons for their choice, none of the subjects indicated the relative location of the item. Rather, they explained their choices by pointing out superior features of the chosen item. Of course, since the items were in fact indistinguishable in all relevant respects, no such superior features were present. The subjects were confabulating.

The results of this experiment, and others that followed, are quite surprising. They suggest that we are tremendously bad at introspecting on the reasons for our choices, and all too naturally come up with irrelevant explanations for them. We are often completely unconscious of the actual reasons for our choices. If this is the case, it puts our conception of ourselves as self-determining agents in jeopardy.

In this week’s Newsweek, Sharon Begley reports on a fascinating new study by Daniel Casasanto that reveals a pervasive spatial bias that depends on handedness. According to the study, subjects associate positive ideas with the region of space that corresponds to their ‘strong’ hand. For example, right-handed subjects judge stimuli presented on their right as more positive (e.g., good, intelligent, happy, attractive) than those presented on their left. This pattern is reversed in the case of left-handed subjects.

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How do we know when to stop brushing our teeth?

800px-Border_Station_Torkhemn_by_James_G_Pinsky_2006In the course of any given day, the number of snap decisions we are called upon to make is staggering. Simply getting to the office in the morning demands decisions about what to wear, when to leave the house, what route to take, where to park the car, and so on. Many of these involve considerable deliberation, especially when something sudden and unexpected happens that interferes with the decisions we would normally have made – the car not starting, high density traffic on our regular route, a meteor striking our office building, etc.

However, the vast majority of our decisions are made on the fly – they seemingly involve no deliberation at all. Should I use the big black coffee mug, or the smaller blue one? Having left the house, do I then go on the paved path, or simply cut through the lawn towards my car? Fiddle with the radio and only then drive, or the other way around? Even more subtle examples are ubiquitous. How should I pick up the coffee mug, left hand, right hand, by the handle, from above? How firmly should I press the toothbrush to my teeth, and when have I brushed sufficiently? How much pressure on the gas pedal would allow me to bypass that geriatric SUV safely? The list is endless.

Most of these decisions seem to involve no deliberation that we are aware of at all, and yet, it seems obvious that we are there, making them. In a sense, they are automatic, and yet, we’re the ones making them. At the very least, it seems to us that we could have done otherwise.

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Consciousness. Know it when you see it?

Because doctors are shunning the latest diagnostic techniques available, and going instead with their instincts, they’re misdiagnosing levels of consciousness. Experimenters found that of 44 patients diagnosed as being in a vegetative state, 18 were found to be in a minimally conscious state (so, capable of feeling pain). And of 41 patients diagnosed as being in a minimally conscious state, 4 had emerged from it without their doctors noticing.

When a patient is apparently comatose, the techniques of the phenomenologist are unavailable to the practicing MD. Never mind anti-behaviourist scruples, detecting consciousness is, in practice, a process of skilled behavioural observation.

For the findings go here. For an article on the findings in The Economist, go here.

Related articles:
£1.99 - small The Search for Neural Correlates of Consciousness
By Jakob Hohwy, Monash University
(Vol. 2, April 2007)
Philosophy Compass

£1.99 - small Theories of Consciousness
By Uriah Kriegel, University of Arizona/University of Sydney
(Vol. 1, February 2006)
Philosophy Compass

Welcome to the world of tomorrow! Artificial brain just 10 years away…

BBP_NeuroColumn2In 1950, Alan Turing famously predicted that within 50 years we would have a computer capable of passing his ‘Imitation Game’ Turing Test, and thereby satisfying his criteria for intelligence. Unfortunately, Turing’s estimate was a little wide of the mark, but efforts to satisfy his test continue. Nevertheless, the crusaders of artificial intelligence, or ‘AI’, appear confident of closing in on their mark. In fact, yesterday at the TED Global conference in Oxford, Henry Markram, director of the Blue Brain Project, suggested that a functioning, artificial human brain running as a simulation will be constructed within the next 10 years. Markram’s project has already simulated aspects of a rat’s brain, but Markram is aiming bigger: “we cannot keep on doing animal experiments forever”, he said. Continue reading “Welcome to the world of tomorrow! Artificial brain just 10 years away…”

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