an appropriate error

Anna Airoldi, the translator of Mind Hacks into Italian has noticed a fantastic error in the published book. She writes

(170) 1st paragraph of “How it works”;
I’m not entirely sure this is a real typo, considering the topic discussed in the paragraph, but “conservations” shouldn’t just be “conversations”?

She’s absolutely right – it should be ‘conversations’ not ‘conservations’. But although it is an error, in this case it is an appropriate error, because it appears in Hack #52 ‘Robust Processing Using Parallelism’ which discusses how we can read errorful or ambiguous sentences using multiple interacting levels of information to construct meaning. Normally this is a good thing, but it appears that in this particular instance the meaning was so obvious that our normally diligent editing process didn’t spot the mistake (my mistake in origin, incidentally)!

2005-12-30 Spike activity

Quick links from the past week in mind and brain news:


Slate asks the question “Is Anorexia Genetic?: What the newest theory leaves out”. A commentary on a recent Newsweek article discussed previously on Mind Hacks.

“Language affects ‘half of vision'” says somewhat misleading title that belies some interesting research in colour perception and categorisation.

Scientific American considers recent research on the psychology of suicide bombers and discounts popular myths about the perpetrators.

People consistently pour larger measures of alcohol into short wide glasses than tall thin ones.

Language Log investigates the science behind recent media claims that Agatha Christie novels are ‘good for the brain’.

The Distorted Tune Test

Ever wondered if you are tone-deaf? The Distorted Tune Test page can help. You listen to 25 simple tunes and judge whether they are played correctly or not (it takes about five or six minutes). Based on your responses, you’ll be told how well you can judge pitch. If the results suggest you are tone-deaf then you are eligable to take part in a US National Institute of Health study into the conditions, so that’s some compensation.

Handbags at 40 paces


Clinical syndromes are not God’s gift to cognitive neuropsychology: a reply to a rebuttal to an answer to a response to the case against syndrome-based research.”

Caramazza and Badecker get their slap-down in early during a heated 1991 debate on whether it is best to study the symptoms or syndromes of brain injury when attempting to theorise about normal cognitive function.

Link to PubMed entry for Caramazza and Badecker paper.

Hack #104: Change the length of your arms!

Here’s a fantastic party-trick, if it works as reported in the Journal of Vision – make your arms feel like they are different lengths using a simple cut out piece of card.

Now, we talked about perception of depth in the book (Hack #22) and about how the senses interact (Chapter 5). One common theme was how visual information often tended influence our perception of information in the other modalities (at least for spatially organisation information, see Hack #53). What Nicola Bruno from the University of Trieste, and colleagues, seem to have found is an instance where a classic illusion of visual depth can distort your perception of your own body.

Ames’ trapaziodal window works by virtue of the assumption that things which appear larger are often just closer by. The Window (see a demo here) is a trapazoid, so that it gives the same appearence as a square with one side further away than the other. Like this:


Just like this the retinal-image is ambiguous between a trapazoid viewed flat on, and a square viewed with one side closer than the other. Normally you can use other information, like comparing the image between your two eyes, to deduce the correct perception of depth, but if you close one eye your brain has to fall back on just the ambiguous image information. And it seems your brain thinks squares are more likely and will deliver to your consciousness the perception of a slanted object, rather than a correct, flat-on, impression.

What Bruno et al did was have participants hold versions of the trapazoidal window illusion and judge the level of slant. Not only did they systemmatically mis-judge the slant of the object (despite getting clear information on how far away both sides were via the proprioception of their hands), but some participants reported ‘a stiking prioprioceptive distortion’ – namely that one hand appeared to be further away than the other, or one arm appeared longer than the other!

Unfortunately the research is only reported in abstract form (here) so I can’t get any more details of how exactly they built the illusionary trapazoid, but you can bet that I’ll be trying it out in the next few days. I suspect that, like the body schema illusions (Hack #64), this effect will work strongly on only a few people, so I’ll have to try it on a bunch of people before getting anything. I’ll let you know the results of my experiments, and I’d love to hear from anyone else who trys it.

The Mind-Body Problem – Who Cares?

Guy Claxton said this a few years ago in the Journal of Consciousness Studies:

Any discussion of the causal status of conscious experience has to start, therefore, with the recognition that what appears to be a dispassionate enquiry is actually a question of life and death importance to which there is only one permissible answer.

The preceeding context is given below the fold…

Continue reading “The Mind-Body Problem – Who Cares?”

Variable man

PKDrobot.jpgThe Economist reports that in Japan, increasing importance is being placed on robots that look and act like humans. The article further argues that the focus on humanoid robots is driven, at least in part, by a desire to avoid the culture’s strong social conventions.

Karl MacDorman, another researcher at Osaka, sees similar social forces at work. Interacting with other people can be difficult for the Japanese, he says, “because they always have to think about what the other person is feeling, and how what they say will affect the other person.” But it is impossible to embarrass a robot, or be embarrassed, by saying the wrong thing.

Meanwhile, Wired offer their list of the ‘50 Best Robots Ever‘.

Is this robot week or something?

Link to Economist article ‘Better than people’.
Link to Wired article ‘The 50 Best Robots Ever’.
Link to previous post on the ‘Uncanny Valley’ in robot design.