Seasonal wishes

I would just like to take this opportunity to wish Mind Hacks readers a happy seasonal festival and I hope you experience an appropriate positive emotion during your marking of the period.

If you’re interested in a little seasonal psychology, Frontal Cortex has an excellent piece on the psychology of Hanukkah, the Jewish festival that involves 8 days of gift giving.

Curiously, it involves the peak-end rule and research with colonoscopies and I’ll leave you to discover the rest.

I’ll be having a very Paisa Christmas with everything kicking off today so Feliz Navidad y Pr√≥spero A√±o Nuevo from Colombia.

Link to Frontal Cortex on Hanukkah and Colonoscopies.

Vintage brain graphic art t shirt

The image is from a tshirt that combines a Victorianesque brain print with distressed material to create wonderful vintage neuroscience clothing.

My only concern is that it’s a CafePress t-shirt and from what I remember they use iron-on process which give the designs a kind of plasticy feel but maybe they’ve changed that by now.

Either way the design is simply fantastic and it looks particularly good on this gold-on-black combination.

Link to vintage brain graphic art t shirt.

Humour as social bargaining

3QuarksDaily has an interesting piece on the psychology of humour and how it is used to negotiate and establish social hierarchies.

The article looks at two theories of humour that try understand what makes something funny. A common explanation is the ‘incongruity’ idea, that suggests when something is suddenly out of context it is more likely to seem funny.

But as the article notes, these theories “fail to explain why we are amused by certain instances of incongruity ‚Äì a man showing up to his job at a real-estate agency with a ‚Äúkick me‚Äù sign on his back ‚Äì but not others ‚Äì a man showing up to his job at a real-estate agency with a cure for cancer”.

The other approach is the ‘superiority’ theory, that suggests that humour is used to establish social hierarchies – those considered objects of humour are further down the social ranking.

But it’s also the case that we seem to use it as a form of flattery for our superiors – various studies (nicely summarised in this NYT article) find that we are much more likely to laugh at the jokes of people higher up the social hierarchy.

The 3QD piece considers the role, development, and rather intriguingly the morality of humour. It’s a little short on links to actual studies which is a little frustrating but it otherwise an interesting and informative exploration.

Link to 3QuarksDaily article ‘Is Humor Immoral?’.

Neuropod on HM, brain banking and 2008 highlights

The latest Nature Neuropod podcast has just hit the wires and as is fitting for the December edition it contains a great roundup of the year’s neuroscience highlights.

There’s also a tribute to recently departed HM from neuropsychologist Susan Corkin, a visit to the UCL brain bank (check the wonderfully appropriate Hammer Horror German accent) and some interesting updates from the world of molecular neuroscience.

In the final section, Nature Neuroscience editor Charvy Narain discusses her highlights of the year in new discoveries and what better way to end the year.

Link to Neurpod page and streaming.
mp3 of December podcast.

Out of sight but not out of mind

Not Exactly Rocket Science discusses the case of a man who experiences the world as a blind man, but who is able to navigate through rooms despite having no conscious visual experience.

TN was a doctor before two successive strokes destroyed his ability to see. The first one severely damaged the occipital lobe on the left side of his brain, which contains the visual cortex. About a month later, a second stroke took out the equivalent area on the right hemisphere [see MRI scan image on the left]. TN is one-of-a-kind, the only known patient with damage like this in the entire medical literature. The fibres that connect the occipital lobes on the right and left halves of the brain have also been severely damaged and tests reveal that no blood flows between these disconnected areas.

Alan Pegna from the University of Bangor in Wales was the first to study TN’s abilities after he was recovering from this second stroke in a Swiss hospital. Pegna was the first to discover TN has an ability called blindsight, that allows him to unconsciously detect things in his environment without any awareness of doing so. He could correctly guess the emotions playing across the faces of other people. And as he did so, his right amygdala – an area of the brain involved in processing emotions – became active.

Blindsight is a condition where, after brain injury, patients lack conscious visual experience but can perform some visual tasks successfully despite thinking they are just guessing.

The first case of blindsight was reported in 1974 by neuropsychologist Larry Weiskrantz, although as with the majority of blindsight cases the patient wasn’t completely blind – in this case it was only for vision on the left hand side.

However, the patient was still able to reliably point to the locations of lights flashed up in the area, despite having no conscious experience of seeing them.

Despite damage to the cortical visual areas in the occipital lobe, it is likely that the earlier subcortical areas, such as the lateral geniculate nucleus (LGN) and the superior colliculus, allow for decision making on the basis of unconscious visual information.

In the new study, the patient is able to use this to avoid obstacles in his path, despite not being conscious of ‘seeing’ them.

This patient has a complete blindness and can complete relatively complex visual tasks without conscious awareness, making him one of the most interesting cases to come to light.

As well as being brilliantly written, the post is illustrated with a video of him avoiding obstacles in a room while walking. Impressive stuff.

Link to NERS post on blindsight case.
Link to study.
Link to DOI entry for same.

Encephalon 61 jingles in

The 61st edition of the Encephalon psychology and neuroscience writing carnival has just made a seasonal entrance and has some quality holiday reading from the last fortnights mind and brain blogging.

A couple of my favourites include Cognitive Daily’s post on an interesting visual imagery experiment that addresses whether it is sexist to think men are angrier than women, and an awesome (and I mean awesome) visual illusion posted on the excellent Illusion Sciences blog.

This edition has a remarkable number of high quality article, so do wander over and have a look.

Link to Encephalon 61.

Triggering the dreamy state

The great British neurologist John Hughlings-Jackson famously described the ‘dreamy state’ reported by some epileptic patients during seizures where they experienced complex hallucinations – sometimes of scenes and faces, feelings of false familiarity and a feeling of ‘weirdness’ or ‘strangeness’.

A study published last year in neurology journal Brain re-examined these experiences by deliberately triggering them by electrically stimulating the brain.

The participants were all patients with epilepsy who were having neurosurgery to treat their otherwise untreatable seizures and the researchers, led by neurologist Jean-Pierre Vignal, specifically stimulated areas in the mesial [inner] temporal lobes.

The feelings of false familiarity are what we normally called d√©j√† vu, but actually we tend to misapply this term as it means ‘already seen’ and refers specifically to a false familiarity for visual perception.

However, it can also occur for anything we experience, such as hearing other people say things, and is more correctly called d√©j√† v√©cu (‘already experienced’) in the literature.

Here are a few of the triggered experiences:

D√©j√† v√©cu (3 volts, right amygdala) – “It’s like yesterday evening … I have the impression that everything around me has been here before, that it has already happened, I feel as if I am going backwards in time”

Scene: reliving a parachute jump (3.5 volts, right hippocampus)

Familiar television advertisement (4 volts, right amygdala)

Impression of being elsewhere (3 volts, right hippocampus)

Scene from childhood (2 milliamps, right amygdala) – “Vision of a bald man dressed in black, coming towards her from behind; associated with a feeling of imminent death; she is pale, with piloerection. She is re-experiencing an experience of anaesthesia by facemask during a tonsillectomy at the age of 14 years”

Impression of being someone else (2 milliamps, left amygdala)

Impression of leaving his body (2.5 milliamps, left amygdala)

Night-time scene (1.2 milliamps, left hippocampus) – “I’m starting to see lots of things, loads of people … it’s still vague and strange. I’ve got an initial picture, a memory … I feel locked in again, something to do with the evening, the night … it’s strange … . like after a party, sad things … there is a mixture of last night and this morning … ‚Äô These remarks were peri-ictal [during the seizure]. After the end of the discharge, there was complete amnesia.”

Scene (4 milliamps, right hippocampus) – “It’s starting, it’s rising up to my eyes … I’m always frightened of something … I feel something, like in dreams, I always see people, loads of people, people that I see in the hospital…”

Familiar character from a film (1.5 millamps, left amygdala)

Ill-defined, unpleasant vision (1.5 milliamps, left hippocampus)

Familiar vision that he is unable to describe (1.5 milliamps, left parahippocampal gyrus)

Vision of a familiar person (1.5 milliamps, left parahippocampal gyrus)

Recent scene (1.5 milliamps, right hippocampus) – “I see myself playing the drums, with people from my family listening to me”

The technique of electrically stimulating the brain to trigger certain experiences was pioneered by Canadian neurosurgeon Wilder Penfield and there’s an excellent account of his life and work on Neurophilosophy if you’d like some background.

This new study is open-access and completely fascinating, so is definitely worth a read.

Link to ‘The dreamy state: hallucinations of autobiographic memory evoked by temporal lobe stimulations and seizures’.