NEWS - PRESS RELEASES

Oprah, Luke Skywalker and Maradona - = new study=20 investigates how our brains respond to them

Research reveals how visual and = auditory=20 information converges into the firing of single neurons

Issued on 24 July 2009

Professor Quian Quiroga is contactable via email = rqqg1@le.ac.uk

Please email him first in order to fix phone = interviews for a=20 time that is mutually convenient

Pictures paint concepts of a thousand words- now, for the = first=20 time, scientists studying the brain have worked out how = words paint=20 concepts in our minds.

The team, including Professor Rodrigo Quian Quiroga at = the=20 Department of Engineering of the University of Leicester in = the UK,=20 Professor Itzhak Fried at the University California Los = Angeles and=20 Professor Christof Koch at the California Institute of = Technology,=20 has published these findings in the journal Current Biology. = It is=20 published online on 23 July and in the print issue on 11 = August.

The results are important for understanding how = perception and=20 memory formation occurs.

Professor Rodrigo Quian Quiroga, head of Bioengineering = at the=20 University of Leicester, led the study which concluded that, = although processing of visual and auditory information occur = along=20 completely separate pathways, the visual and auditory = processing=20 routes converge to end up firing the same single = neurons.

He said: =E2=80=9CDifferent pictures of Marilyn Monroe = can evoke the same=20 mental image, even if greatly modified as in = Warhol=E2=80=99s famous=20 portraits. This process relates to one of the most = fascinating=20 questions in neuroscience: how do neurons in the brain = manage to=20 abstract and disregard irrelevant details to recognize = highly=20 variable pictures as the same person?=E2=80=9D

Professor Quian Quiroga said various studies had provided = insights into how visual information is processed in the = brain. He=20 added:

=E2=80=9CInterestingly, in humans, the same = =E2=80=9Cconcept=E2=80=9D of Marilyn can be=20 evoked with other stimulus modalities, for instance by = hearing or=20 reading her name. Brain imaging studies have identified = cortical=20 areas in the human temporal lobe that are selective to = voices and=20 words. However, how visual, text and sound information can = elicit a=20 unique percept is still largely unknown.=E2=80=9D

The University of Leicester team in collaboration with = UCLA and=20 Caltech used presentations of pictures, spoken and written = names to=20 show that single neurons in the human hippocampus and = surrounding=20 areas respond selectively to representations of the same = individual=20 using different sensory prompts. For example a neuron = responded to=20 three pictures of the TV host =E2=80=9COprah = Winfrey=E2=80=9D, to her name written=20 in the computer screen and to a computer synthesized voice = saying=20 =E2=80=9COprah=E2=80=9D; another one fired to different = pictures and the written and=20 pronounced name of =E2=80=9CLuke Skywalker=E2=80=9D, from = the classic movie =E2=80=9CStar=20 Wars=E2=80=9D. Another neuron fired strongly to the pictures = and the written=20 and spoken name of the ex-football star =E2=80=9CDiego = Maradona=E2=80=9D, even to a=20 picture of Maradona in the soccer field when his face was = not=20 visible but the patient still recognized as Maradona.

They also found that such degree of abstraction = =E2=80=93in the sense=20 that neurons fired the same to different pictures or the = name of a=20 particular person- increased along the hierarchical = structure within=20 the areas they recorded from.

Moreover, Professor Quian Quiroga found neurons = responding to his=20 own pictures and name, thus suggesting that such neuronal=20 representations can be generated relatively fast, because he = was=20 unknown to the patient a day or two before the recording = took=20 place.

Said Professor Quian Quiroga: =E2=80=9CThese results = demonstrate that=20 single neurons can encode concepts in a very abstract way, = even if=20 evoked by different sensory modalities=E2=80=9D

The study breaks new ground by demonstrating how neurons=20 previously studied by the team respond not only to picture, = but to=20 written and spoken names too.

Professor Quian Quiroga said: =E2=80=9CThe processing of = visual and=20 auditory information follows completely different cortical = pathways=20 in the brain, but we are showing that this information = converges=20 into single neurons in the hippocampus, at the very end of = these=20 pathways for processing sensory information.

=E2=80=9CThis work gives us further understandings of how = information is=20 processed in the brain, by creating a high level of = abstraction=20 which is important for perception and memory formation given = that we=20 tend to remember abstract concepts and forget irrelevant=20 details.=E2=80=9D

NOTE TO NEWSDESK:

For more information, contact:

Rodrigo Quian Quiroga

Professor of Bioengineering, Department of Engineering,=20 University of Leicester

Professor Quian Quiroga is contactable via email rqqg1@le.ac.uk

Please email him first in order to fix phone interviews = for a=20 time that is mutually convenient

www.le.ac.uk/neuroengineeri= ng

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