Cognitive daily on ‘childhood amnesia’

Cognitive Daily has an elegant summary of research on why we don’t remember the first years of life. The results suggest that it may be because young children lack the language resources to support the necessary memories.

I would be tempted to quote some of the post here, but its described so succinctly its probably best just to read the original.

Link to ‘Why do we forget our childhood?’ from Cognitive Daily.

Optical street art of Julian Beever

Julian Beever is a street artist who takes advantage of the way the brain understands the world to create some amazing artwork.

The brain works out our 3D experience of the world from the 2D light patterns that fall onto our retina at the back of the eye.

This process takes advantage of many of our implicit assumptions of the world, such as the fact that textures will fade as they go farther away, parallel lines will tend to converge in the distance and that objects will seem larger the closer they are.

beever_swim.jpg

Julian Beever’s art uses a knowledge of these processes, so when seen from a certain angle, the pictures fool the visual system’s inbuilt processes to produce a false sense of depth.

beever_swim_wrongview.jpg

When seen from an alternative angle, the illusion breaks-down, and it’s possible to see how the artwork was created.

There’s plenty more examples of this amazing effect on Julian’s pages that are well worth checking out.

Links to Julian Beever’s homepage and street art page.
PDF of notes on ‘An Introduction to Visual Perception’.

At last! Female orgasm neuroimaged

kiss.jpgFinally, someone has done a neuroimaging study of the female orgasm.

Although the paper from this study has not been published yet, if the conference reports are anything to go by, it may be the first functional neuroimaging study of orgasm in healthy human females.

My only caveat is the rather random way this story is being reported (e.g. ‘Brain scans detect fake orgasms’) and the seemingly odd quotes from the researcher involved (from a BBC News story):

Professor Holstege said: “Women can imitate orgasm quite well. But with genuine orgasm”, he said: “What we see is an extreme deactivation of large portions of the brain hippocampus and especially the emotional parts involved with fear… And if you are fearful, it is very hard to have sex. It’s very hard to let go.” He said this was useful for men to know. “When you want to make love to a woman, you must give her the feeling of being protected.”

If reported correctly, Prof Holstege seems to have gone from a discovery about a reduction in brain activity (possibly based on a weak clich√© that the amygdala circuit is the ‘fear’ part of the brain) to advice on ‘how to make love to a woman’.

Come again ?

Link to story from newscientist.com
Link to story from BBC News.

Anaesthesia can lead to sex delusions

windows.jpgThe Arizona Daily Star is reporting that doctors are being warned that some general anaesthetics are associated with sexual dreams which some people may remember as real.

Although it is almost impossible to verify how often sexual hallucinations occur, some studies indicate it happens in 1 percent to 3 percent of anesthetized patients, Strickland said. With some anesthetic drugs – such as ketamine or propofol – the incidence is up to 5 percent.

Just why it happens is not well understood. But the risk is higher under lighter, sedating anesthesia than under deep anesthesia, doctors have found.

Link to article from Arizona Daily Star (via BoingBoing)
Links one and two to cases on PubMed.

Neurotheology via Numenware

numenware-small.jpgNumenware is a recently re-launched blog that covers the developing world of neurotheology – the neuroscience of spiritual experience and belief.

The site is authored by Bob Myers, who manages to approach the subject in a critical but non-dogmatic way and avoids scoring easy points on complex topics.

Some of my favourites include a post musing about a neurological basis of average age of enlightenment, one on developmental neurotheology, and note on the possible adaptive value of near-death experiences.

Link to numenware.com

Epilepsy and the risk of psychosis

epilepsy_eeg_trace.jpg

A study published online by the British Medical Journal suggests that people with epilepsy or a family history of epilepsy may be more likely to develop schizophrenia or psychotic symptoms.

Researchers from the University of Aarhus analysed the records of 2.27 million Danish people, and found the risk of schizophrenia-like psychosis slightly raised in people with epilepsy, or those with family members who have epilepsy.

The absolute risk still remains small however, as only 1.5% of the people with epilepsy went on to develop psychosis.

The significance of these findings are in the suggestion that epilepsy and psychosis may have some common genetic influences. This influence is likely to be complex however, as demonstrated by a curious interaction.

The study found that people with epilepsy were more likely to develop psychosis if there was no family history of psychosis or schizophrenia.

Link to story from Yahoo News.
Link to study abstract.

UPDATE: The BMJ have just published a ‘rapid response‘ I submitted about the article’s findings.