Technology to see through other people’s eyes

Neurotech analyst Zack Lynch has an interesting post on his Brain Waves blog about trying out the EyeSeeCam, a wearable camera that tracks eye movements so it can film exactly where the person is looking, allowing others to literally see the world through somebody else’s eyes.

Lynch wore the device while at the recent Society for Neuroscience conference and describes how it works:

EyeSeeCam is based on the combination of two technologies: an eye tracking and a camera motion device that operates as an artificial eye. The challenges in designing such a system are mobility, high bandwidth, and low total latency. These challenges are met by a newly developed lightweight eye tracker that is able to synchronously measure binocular eye positions at up to 600 Hertz. The camera motion device consists of a parallel kinematics setup with a backlash-free gimbal joint that is driven by piezo actuators with no reduction gears. As a result, the latency between eye rotations and the camera is as low as 10 milliseconds.

EyeSeeCam provides a new tool for fundamental studies in vision research, particularly, on human gaze behavior in the real world. This prototype is a first attempt to combine free user mobility with biological image stabilization and unrestricted exploration of the visual surround in a man-made technical vision system.

Does this remind anyone else of Strange Days?

Link to Zack Lynch on wearing the EyeSeeCam.
Link to scientific paper with cool video.

The oscillations of Rudolfo Llin√°s

The New York Times has an excellent profile of free-thinking neuroscientist Rudolfo Llin√°s who is renowned for his theories on the importance of brain oscillations and his unique take on consciousness.

Now based in New York, Llin√°s is a native of Colombia and is considered one of the most important living neuroscientists.

He views the brain as a neurophysiologist but applies his knowledge of neurobiology to understanding some of the bigger questions, such as conscious experience and mental illness.

When the brain is awake, neurons in the cortex and thalamus oscillate at the same high frequency, called gamma. “It’s like a Riverdance performance,” Dr. Llinás continued. “Some cells are tapping in harmony and some are silent, creating myriads of patterns that represent the properties of the external world. Cells with the same rhythm form circuits to bind information in time. Such coherent activity allows you to see and hear, to be alert and able to think.”

But at day’s end, cells in the thalamus naturally enter a low-frequency oscillation. They burst slowly instead of firing rapidly. With the thalamus thrumming at a slower rhythm, the cortex follows along. You fall asleep. Your brain is still tapping out slow rhythms, but consciousness is suspended.

So if a small part of the thalamus gets permanently stuck at a low frequency, or part of the cortex fails to respond to the wake-up call, Dr. Llin√°s said, an abnormal rhythm is generated, a so-called thalamocortical dysrhythmia.

And Llin√°s claims that specific dysrhythmias can be seen in various brain problems each of which might represent a specific breakdown in the normal oscillations of the brain.

Link to NYT ‘In a Host of Ailments, Seeing a Brain Out of Rhythm’.

Thanks for the memories HM

The densely amnesic Patient HM, one of the most famous and important patients in the history of neuroscience, has passed away.

HM, now revealed as Henry G. Molaison, suffered from temporal lobe epilepsy that was not helped by existing drugs and so was referred to neurosurgeon William Scoville in 1953.

Scoville attempted a new type of operation to remove the parts of the brain which triggered the seizures, cutting out the majority of the hippocampus on both sides of the brain, along with the amygdala and parahippocampal gyrus.

This left HM with a dense antereograde amnesia, meaning that while his memory for pre-surgery events was generally very good, he was unable to create new conscious long-term memories.

His ability to learn new skills and obtain conditioned associations remained intact, however, and the differences in his memory abilities and the precise knowledge of which parts of the brain were missing allowed some of the first insights into the neuropsychology of memory.

The initial study on HM and his dense amnesia was first published in 1957 by Scoville and the young psychologist Brenda Milner. It has since become one of the most widely cited and widely taught of all neuropsychology case studies.

However, HM continued to participate in research studies since his initial appearance in the scientific literature and was known among researchers for his warm and easy going personality.

The most recent study on HM was published only this year and examined the linguistic content of his crossword puzzles, of which he’d been a fan of for the whole of his adult life. The study examined whether his language skills had been affected by years of dense amnesia.

They hadn’t, suggesting that once acquired, the maintenance of written language skills doesn’t seem to require intact medial temporal lobes.

Much of the later work with HM was completed in partnership with neuropsychologist Suzanne Corkin, who wrote an article [pdf] for Nature Reviews Neuroscience in 2002 that was part tribute and part research summary, detailing his massive contribution to our understanding of memory.

UPDATE: The New York Times has an excellent obituary for HM.

Link to announcement of HM’s death (via MeFi).
Link to classic case study.
pdf of 2002 review article.

The dead stay with us

Scientific American Mind Matter’s blog has just published an article I wrote on grief hallucinations, the remarkably common experience of seeing, hearing, touching or sensing our loved ones after they’ve passed away.

Grief hallucinations are a normal reaction to having someone close to you die and are a common part of the mourning process, but it’s remarkable how often people are embarrassed to say they’ve had the experience because they worry what others might think.

I was inspired to write the piece after reading a wonderful paper, published in Transcultural Psychiatry, by psychiatrist Carlos Sluzki on the cultural significance of one Hispanic lady’s post-grief hallucinations.

My reference to the shadow cat draws on the intro to Sluzki’s article which must be one of the most beautiful openings to an academic article I’ve ever read.

I note that there’s not a great deal of research on grief hallucinations, despite how common they are, although I picked up on a study during the last few days which addressed these curious phenomena in a study on psychotic symptoms.

A thorough population survey in France that appeared earlier this year found that grief hallucinations were the most frequent ‘psychotic’ symptom in individuals without mental illness.

It’s also interesting to read the comments that the article has generated. I really seemed to have pushed a few buttons.

I’m quite proud of the piece though, and it’s a vastly under-discussed and under-researched topic that affects huge numbers of people.

Link to SciAm piece ‘Ghost Stories: Visits from the Deceased’.
Link to Carlos Sluzki’s excellent article.
Link to DOI for same.

SciAmMind on brain injury, stimulation and diversity

The new Scientific American Mind has just arrived and has a number of fantastic freely available features articles online.

One of the most interesting articles is about post-accident brain treatments, used in the hours and minutes following severe injury, to protect the brain and minimize the chances of long-term cognitive problems.

The best hope for improved healing lies neither in new medications, which have been disappointing so far, nor in exotic fixes involving stem cells and neural regeneration, which are at least a decade away, researchers say. Rather the biggest gains will likely result from advances in emergency room and intensive care practices that curtail the secondary damage from TBI. The methods include slowing the brain’s metabolism with cooling techniques, removing part of the skull to relieve intracranial pressure and injecting an experimental polymer “glue” to repair damaged brain cells.

Other articles discuss mild traumatic brain injury and the role of emotional disturbance in the following impairments, deep brain stimulation, the difficulty of making life changing decisions after our 20s, and intelligence throughout the animal kingdom.

Link to latest SciAmMind.

Cheer up you waster

The Dummies series of books have been hugely successful guides to everything from fixing computers to learning languages although they’ve recently started to publish self-help books on psychological themes.

Unfortunately, they don’t fit quite as well into the general theme and hilariously, one of the titles is called Building Self-Confidence for Dummies.

UPDATE: Some great follow-ups grabbed from the comments (thanks skagedal and OmegaSupreme!):

There’s also the “Complete Idiot’s Guide” series, they have the similarly wonderfully named title “The Complete Idiot’s Guide to Enhancing Self-Esteem”.

Troy McClure in the Simpsons had a self help video called “Get Confident, Stupid” !

Link to book details (thanks Catrin!).