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This week’s News Scientist’s cover story looks at the tricks our mind plays to create what we consider is reality. I always like this kind of information because of its philosophical implications: THERE IS NO OBJECTIVE REALITY! Everything we perceive, know and believe to be true is made up in one way or another by our subjective minds. I sometimes wonder what the world would be like, if all of us would live according to such understanding … the optimistic part in me likes to think we would have much more tolerance and acceptance of the other, and therefore less conflict and a more peaceful world …

Back to the cover story titled “Mind Tricks: Six ways to explore your brain”. As the headline suggests, it looks at what scientists just begin to understand as being the workings of our brain; it does that by ‘exploring’ aspects of perception, memory, attention, body image, the unconscious mind and the curious consequences of our brains being split in two. The six posts mentioned below will summarise those findings.

• Discontinuity of perception
• The unreliable body image
• Curious consequences of the split brain

Perceived reality is not at all reality; it’s a stitched up patchwork of selected impressions and guesswork. Take our visual impressions. In the centre of our retina we have a small patch of densely crowded photoreceptors called the fovea. This spot is the only part of the eye capable of seeing with the rich detail and full colour we take for granted. To get an idea of its size: it covers an area of our visual field that is no bigger than the spot the moon takes up in the sky - yet it feeds our visual system with almost all of its raw information.

So how do our eyes build up a picture? Not by continuously scanning our environment but by darting around, by fixating a certain spot for a fraction of a second and then moving on. These jerky movements between fixations are called saccades, and we make about three per second, each lasting between 20 and 200 microseconds. During those saccades we are effectively blind; the brain does not process the information picked up in between because the eyes move too rapidly.

Despite their short duration we can actually capture saccades visually. One way is to look in a mirror and flick our focus from side to side; however hard we might try though, we cannot see our eyes move; because the saccade is motion, our brain does not pay attention to it. Another way to catch saccades is the so-called frozen-time illusion: it’s the sensation we get when looking at a clock, the second hand appears to freeze for a brief moment before moving on.

This particular effect is quite interesting because some scientists believe that it partially explains how vision works: to compensate for the temporary shut-down, our brain makes a guess at what it would have seen, and it does so retrospectively. In other words, the 100 or so milliseconds of blindness gets back-filled with the image that appears after the saccade is over; the “second” then lasts about 10 per cent longer than normal, which is enough for us to notice. But it’s not only guesswork that is used to justify the idea of backfilling; short-term and long-term visual memories retaining information from previous fixations are also suggested as ways of filling gaps and creating a continuous here-and-now visual experience (Andrew Hollingworth, Visual Cognition, vol 14, p 781).

It is not only vision though that is affected by discontinuity of experience; our auditory system is also full of gaps and glitches that the brain cleans up so we can make sense of the world. This is especially true of speech. “Phonemic restoration” is the a term to describe how our brain pastes in the sounds that obscured or distorted people’s voices in everyday situations.

A good demonstration of this effect was published last year by Makio Kashino of NTT Communication Science Laboratories in Atsugi, Japan. He recorded a voice saying “Do you understand what I’m trying to say?” then removed short chunks and replaced them with silence. This made the sentence virtually unintelligible. But when he filled the gaps with loud white noise or parts of the sentence being played reverse, the sentence miraculously becomes understandable (Acoustic Science and Technology, vol 27, p 318); the brain replaces the distortion based on the information in the remaining speech signal (Kashino’s sound files are available here).

It seems that the presence of this speech signal is of prime importance; the brain might not switch to possible speech responding circuits unless it detects spoken language (Hearing Research, vol 229, p 132). Another demonstration for this ability to detect meaning from distorted speech signals is a form of synthesised speech called sine-wave speech. Hearing it first it sound unintelligible, a bit like whistling or birdsongs; but if you listen to the same sentence in normal speech and then return to the sine-wave version, it suddenly snaps into auditory focus. Try as you might, you cannot “unhear” the words that you didn’t even realise were words the first time you heard them (listen to demos below by clicking on the yellow triangles to download the associated wav files; more examples can be found here).

What happens when the two gap filing mechanisms come together? Sometimes the visual and other times the auditory system wins out. Take the McGurk effect, in which listening to a series of identical syllables such as “ba ba ba ba” while watching somebody mouth “ba da la va” makes you hear “ba da la va“. Try it for yourself here. On the other hand, when a team of psychologists showed volunteers on a screen a single flash accompanied by two short beeps, those volunteers saw two flashes (Nature, vol 408, p 788). See the illusion here.

The next post will look at the way the brain creates a body image.

[source: New Scientist]

With a clear gender bias, it’s quite sexist - but also quite funny: a company having supposedly created the scent of vaginal fluids and making it available in small vials (like precious perfume) to help guys to get more potent masturbation fantasies. And to underscore their sexist marketing, they’re already flagging the soonish appearance of two further products: “Eighteen” and “Exotic”. Click on the image above to watch the video - it’s quite surreal .

[via Bozomode]

There aren’t too many situations where I want to download low-res video clips from YouTube, but they do exist. My good mate Harry found a simple way of doing just that. He discovered KissYouTube, which makes it about as easy as it can possibly be. You simply take the YouTube URL and put “kiss” in front of “youtube” … like this one is http://www.kissyoutube.com/watch?v=9fohXBj2UEI (no need checking out the video though - it’s a boring maths video and I was too lazy replacing the url ).

You can download the video in its normal FLV (ie Flash Video) format or choose from most other video formats, including specific versions for various portable devices. Thanks buddy!

I just hope their online download is not down too often, as it was right now. Interestingly enough, they did offer a download tool for use in the meantime, supposedly tested on WinXP SP2 + IE7; I haven’t tried that one though.

Chinese mountaineers will carry the Olympic torch to the top of Mount Everest, making the final assault on the world’s tallest peak from a staging camp some 500 yards from the summit. The head of China’s mountaineering team, Wang Yongfeng, said plans for the Everest leg of the torch relay for the 2008 Beijing Olympics were still being finalized, the official Xinhua News Agency reported on Thursday.

From base camp at 17,000 feet, the torch will be taken to a staging area at 27,400 feet and from there to the 29,035-foot summit, Wang said. Taking the torch up Mount Everest is one of the most technically challenging and politically charged events Beijing has planned for the August 8-24 Games. Aside from the physical challenge of climbing the mountain, which straddles the border of Nepal and Chinese-controlled Tibet, the torch had to be designed to burn in bad weather, low pressure and high altitude.

While Beijing hopes the feat will impress the world, groups critical of China’s often harsh 57-year rule over Tibet have decried the torch route as a stunt meant to lend legitimacy to Chinese control. In April, five American activists were expelled from China after unfurling a banner at Everest base camp that read, “One World, One Dream, Free Tibet 2008,” in a dig at the Beijing Games’ official slogan “One World, One Dream.”

[via CNN.com]

Far removed from Coubertin’s 19th century notion of the Games promoting peace, the modern version is nothing but a cynical and insidious exercise in retaining political and economic power structures and, in the process, of making money out of keeping the masses dumbed down. Part of that systemic strategy is the promotion of the idea of separating the spirit of the Olympics from politics, a concept that is absolutely nonsensical. It is illogical because there is no such thing as value-neutrality; it is hypocritical given decades of various political boycotts, and - it is unethical because it leads to the Games being conducted in countries with appalling human rights records. Moving the Olympics to the lofty heights of pure, unspoiled human endeavour also tries to hide their primarily commercial nature, which requires amongst other things that every cycle has to outdo the previous one in terms of stunts - not to simply cater for people’s supposedly voracious thrill appetites, but to allow involved commercial interests to rake in ever-increasing unjustifiable profits. And if there ever was a spiritual or at least deeply religious component to the ancient forebears of today’s revival, both capitalist and communist deconstruction of the sacred have put a clear end to that notion. Choosing so-called Mount Everest as a transition point on the path of the flare of delusion reaffirms how far our so-called civilisation has moved away from its roots to a deeper self-understanding - before the often ruthless and brutal Chinese occupation of Tibet, the summit’s original name was Chomolungma or Qomolangma, which translates as “Mother of the Universe” or “Goddess Mother of the Snows”.