24 February, 2015

Brain goes silent when we talk loud

The part of the brain identified as the command centre for human speech does not actually work when we speak loudly, a study reveals.

The Broca's area -- named after 19th century French physician Pierre Paul Broca -- has been recognised for more than 150 years as the command centre for human speech, including vocalisation.

Now, scientists at the University of California Berkeley and Johns Hopkins University in Maryland are challenging this long-held assumption with new evidence that Broca's area actually switches off when we talk out loud.

"Broca's area shuts down during the actual delivery of speech, but it may remain active during conversation as part of planning future words and full sentences," said study lead author Adeen Flinker.

Neuroscientists have traditionally organised the brain's language centre into two main regions: one for perceiving speech and one for producing speech.

"This finding helps us move towards a view that Broca's area is not a centre for speech production but rather a critical area for integrating and coordinating information across other brain regions," Flinker said.

The discovery has major implications for the diagnoses and treatments of stroke, epilepsy and brain injuries that result in language impairments.

"The results could help us advance language mapping during neurosurgery as well as the assessment of language impairments," Flinker concluded.

The findings were reported in the Proceedings of the National Academy of Sciences.

Source: www.timesofindia.com

24.02.2015

Is your perfume safe?

Several perfumes contain undeclared chemicals that may have serious health implications, according to a report by two environmental advocacy groups in Canada.

To come up with the report, the two groups commissioned independent laboratory testing that identified several potentially harmful chemicals in perfume products including Acqua Di Gio by Giorgio Armani, and American Eagle's Seventy Seven.

According to the report, both contain lilial, an allergen that may prompt estrogen-like effects in the body, and benzyl salicylate, an allergen, as well as many other chemicals, reports The Globe and Mail.

"Anything in your house that smells like a rain forest or a strawberry patch or a pine tree will have these chemicals in them," added Rick Smith, executive director of Environmental Defence, which released the report along with California-based Campaign for Safe Cosmetics.

Dolce & Gabbana's Light Blue fragrance contains several chemicals including butylated hydroxytoluene (BHT), a preservative and stabilizer that has been associated with adverse effects on the thyroid and is a possible carcinogen. 

Source: www.timesofindia.com

24.02.2015

A lie may take care of the present but it has no future