Hormones responsible for lack of concentration

Toronto: Ladies, having trouble concentrating? Blame it on your hormones, Canadian scientists say.

Researchers at the Concordia University in Montreal found that high estrogen levels are associated with an inability to pay attention and learn.

The study, the first to report how hormones can have a direct impact on this impediment, has been published in the journal Brain and Cognition.

"Although estrogen is known to play a significant role in learning and memory, there has been no clear consensus on its effect," said lead researcher Wayne Brake, a professor at the university`s Centre for Studies in Behavioural Neurobiology.

"Our findings, using a well-established model of learning called latent inhibition, shows conclusively that high estrogen levels inhibit the cognitive ability in female

Women have high estrogen levels while they are ovulating. These high levels have also been shown to interfere with women`s ability to pay attention.

"The similarity between human studies and our findings suggest that we have a good model for human learning," said co-author Matthew Quinlan.

"Rodent research is invaluable to us. We can tease out the real contributors and their respective roles in these systems. It is much more difficult to conduct comparable experiments in humans."

Latent inhibition is observed in many species and is believed to be the important part of learning, which enables individuals to interact successfully in their environment. It is a test of new memory formation.

During the study, rats received a pre-exposure phase during which they were repeatedly exposed to a tone, with no consequence.

Once they became used to this tone and ignored it, the test dynamics changed and another stimulus was linked to the tone.

Rats with low levels of estrogen quickly learned that the tone was associated with the new stimulus whereas those with higher levels of estrogen took longer to form this memory.

Brake said: "We only observed this effect in adult female rats. This and our other findings indicate that estrogen directly effects the brain, perhaps by interfering with brain
signalling molecules”.

"Our study helps clear up the controversy about the effects of estrogen, the next step is to look at how this occurs."