Why some people can't tell left from right

Why some people can't tell left from right

It can seem like an almost childish mistake, but a surprising number of adults confuse left from right, and scientists are starting to understand why.

A)

1)

British neurosurgeon Henry Marsh made a mistake in his patient's procedure.

He had drilled out the nerve on the wrong side of his spinal column after making a midline incision in his neck.

2)

Preventable medical errors often involve surgery on the wrong side-for example, an injection into the opposite eye or biopsies from the wrong breast side.

Patient accidents, which by their nature 'never happen' and are largely preventable, prove that not everyone gets it right.

3)

While for some people, telling left from right is as easy as telling up from down, a significant minority - around one in six people, according to a recent study - struggle with the distinction.

B)

4)

" No one has difficulty saying front and back, top and bottom, but saying right to the left is different. This is due to symmetry; changing the orientation reverses it and confuses," says neuropsychology professor Ineke van der Ham.

C)

7)

According to a study published by Van der Ham in 2020, approximately 15% of people rated their identification of left and right as inadequate.

Almost half of the 400 participants used hand-related strategies to identify which.

D)

8)

Researchers tested Bergen's left-right discrimination.

Participants had to identify whether the highlighted hand was left or right by looking at a picture of a stick figure with its arm in different positions, facing toward or away from them.

'It seems simple enough, but it is frustrating to do this 100 times as quickly as possible.'

9)

In the first experiment, the participants sat with their hands on a table in front of them.

"If you looked at the back of the head, so it was aligned with you, people were much faster and more accurate."

"That tells us that the body is involved in this," says Van der Ham.

10)

The next question was whether participants were using cues from their bodies at the time of the test to identify left and right or referring to a stored idea of their body instead.

Next, participants sat with their hands either crossed or uncrossed on the table in front of them and had their hands either visible during the test or covered with a black cloth.

"We were able to identify our bodies as being a key element in identifying left from right," says Van der Ham.

E)

11)

In Van der Ham's experiments, the boost in performance that came from being in line with the stick person was more pronounced in people who said they use a hand-related strategy to tell left from right in their daily lives.

The researchers also found that men tended to respond faster than women.

Research suggests that the more asymmetrical someone's body is, the easier they find it to distinguish left and right.

12)

But it could also be something we learn in childhood, like other aspects of spatial cognition, says Van der Ham.

13)

When they were tested on their ability to locate the correct body part on themselves or a partner after the program, the number of left-right discrimination errors was almost halved.

In a typical classroom, children might label body parts on a diagram rather than their bodies because the latter is more time-consuming and challenging to assess for a teacher, says Gomez.

F)

14)

While there are plenty of everyday scenarios where knowing left from right is essential, there are some situations where it's critical.

For example, a surgeon removing the wrong kidney or amputating the wrong limb would have devastating consequences.

But while some people have to put in more effort to judge left and right, everybody can get left-right decisions wrong, says Gormley.

15)

He hopes that more awareness of how easy it is to make such a mistake will lead to less stigma for those who need to double-check their decision.

"As health care professionals, we spend a lot of time labelling spatial orientations: proximal, distal, superior, inferior, but pay no attention to right or left," he says. "But, of all the spatial orientations, that is the most challenging."