How We Navigate Through Undesired Objects to Reach What We Want

TORONTO – Ever wondered how we always manage to make our way through various things to reach that jelly at the back of the refrigerator? Well, researchers at The University of Western Ontario have now unlocked the mystery of how our brain allows us to avoid such undesired objects.

Canada Research Chair in Visual Neuroscience Mel Goodale, lead author Chris Striemer and colleagues in Western’s Department of Psychology led the study.

“We automatically choose a path for our hand that avoids hitting any obstacles that may be in the way. Every day, we perform hundreds of actions of this sort without giving a moment’s thought as to how we accomplish these deceptively simple tasks,” said Goodale.

For the study, the researchers asked a patient who had become completely blind on his left side following a stroke to the main visual area of the brain to avoid obstacles as he reached out to touch a target in his right – or ‘good’ – visual field.

He could avoid the obstacles as any normal-sighted individual would, but surprisingly, when the experiment was repeated on his blind side, he was still able to avoid them – even though he never reported having seen them.

“The patient’s behaviour shows he is sensitive to the location of obstacles he is completely unaware of,” said Striemer.

“The patient seemed to be as surprised as we were that he could respond to these ‘unseen’ obstacles,” added Goodale.

The findings provide compelling evidence for the idea that obstacle avoidance depends on ancient visual pathways in the brain that appear to bypass the main visual areas that allow us to perceive the world.

Thus, even when the part of the brain that gives us our visual experience is damaged, other parts of the brain still maintain a limited ability to use visual information from the eyes to control skilled movements of the limbs.

Additional experiments have shown that these primitive visual pathways work only in real-time and do not have access to memories, even of the short-term variety.

To explain it, the researchers provided an obstacle in the patient’s blind field but delayed his reach by two seconds, and found that he no longer showed any sensitivity to the object’s location.

The study’s results have important implications for our understanding of what gets lost and what gets spared following damage to the brain’s main visual pathways, and point the way for new approaches to rehabilitation.

The study has been published in the Proceedings of the National Academy of Sciences.

Two Out of Every Three Blind in India are Women

NEW DELHI – Nearly two million people are blind in India but what is startling is that around 66 percent of them are women, government authorities and experts said Thursday, observed as the World Sight Day (WSD).

This year, the focus was on gender and eye care. G.V.S Murthy, a professor of the All India Institute of Medical Sciences (AIIMS), said that out of every three blind in the country, two are women and there is need to bring a gender equity while providing eye care.

He said there was a general assumption that what worked for men worked for women, but this was not true. There were several obstacles beginning from illiteracy, difference in roles and responsibility in decision making, and poverty which resulted in health care for men as a priority.

“There is gender disparity in health services at secondary and tertiary levels where most of the ophthalmologists were men. There is a need to look at empowering women, increasing their physical mobility and economic security,” Murthy said.

Speaking on the occasion, Shalini Prasad, joint secretary in the central health ministry, rued: “Women do not have access because of their gender. We tend to forget that women and girl child cannot reach health facilities due to a number of barriers. To make gender equality a reality, there is a need to make health care accessible.”

Experts said that as more old women are blind, perhaps more financial aid could be given to them. Women to women approach which has more empathy could be one of the steps that could bridge the gender inequality, they said.

G.N. Rao, who heads the L.V. Prasad Eye Institute, said: “As an advocacy tool, the World Sight Day has served its purpose successfully as blindness now is considered as a priority issue in all the health organisations around the world”.

He also endorsed the work of government and private organisations on their initiative called Vision 2020: the Right to Sight.

As a beginning, five pilot projects in poor socio-economic strata of society could be started to demonstrate gender equity, which then could be replicated, he suggested.

As many as two million people in India are corneally blind. Every year, 30,000 more are added to this figure. Half of the people suffering from this can get their sight restored through corneal graft surgery. However, against the annual demand for 100,000 corneas, only 16,000 are available.

Presenting – Claustrophobia

Presenting – Claustrophobia

Claustrophobia is an anxiety disorder in which someone has an intense and irrational fear of confined or enclosed spaces. A person who suffers from claustrophobia may break into a panic when inside a lift (elevator), a bus, an aeroplane, a room with lots of people or any confined space.

What are the symptoms?

These symptoms may be relevant to many types of phobias (irrational fears):

— Sweating
— Accelerated heart rate
— Hyperventilation, or ‘over-breathing’
— Shaking
— Light-headedness
— Nausea
— Fainting
— Fear of actual harm or illness.

A person with claustrophobia may:

— When entering a room, start checking for where the exits are. Position himself/herself near the exits. Feel very uneasy when all the doors are shut.

— Avoid driving or entering a car during times of day when traffic is most likely to be congested.

— Opt for using the stairs rather than the lift (elevator). The reason being fear, rather than the extra exercise.

— Stand near the door at a crowded party – even if it is a large and spacious room.

— Panic when a door is closed and he/she is inside (more severe).