Linked Life Data

10648726

Source:http://linkedlifedata.com/resource/pubmed/id/10648726

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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
2000-2-18
pubmed:abstractText
We examined the coding of sound-source location by ensembles of neurons in the auditory cortex. Broadband noise bursts were presented from loudspeakers throughout 360 degrees in the horizontal plane. Sound levels varied from 20 to 40 dB above neural thresholds. We recorded temporal spike patterns simultaneously at 16 recording sites in area A2 of alpha-chloralose-anesthetized cats. Spike patterns of individual units varied in spike counts and in spike timing as a function of sound-source location. Ensembles of up to 19 units recorded simultaneously demonstrated additional location sensitivity in the form of relative spike counts and relative spike timing among neurons. We used an artificial neural network (ANN) algorithm to recognize ensemble spike patterns and, thereby, to infer the locations of sound sources. The ANN could estimate stimulus locations based on ensemble responses to single-stimulus presentations. Median errors (MEs) averaged 49.2 +/- 11.9 degrees (mean +/- SD; n = 34; chance level, 90 degrees ). The ANN maintained better-than-chance performance even when input spike patterns were expressed as relative spike counts across units (i.e., no information available from absolute spike counts of individual units; ME, 63.0 +/- 11.8 degrees ) or when spike latencies were represented as time relative to the first spike for each trial (i.e., no external time reference available; ME, 54.3 +/- 12.4 degrees ). The ANN performance improved monotonically as the sizes of ensemble patterns were increased by combining patterns across the entire unit sample. The performance by ensembles of 128 units approached the level of localization performance of behaving cats.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:status
MEDLINE
pubmed:month
Feb
pubmed:issn
1529-2401
pubmed:author
pubmed:issnType
Electronic
pubmed:day
1
pubmed:volume
20
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1216-28
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
2000
pubmed:articleTitle
Coding of sound-source location by ensembles of cortical neurons.
pubmed:affiliation
Kresge Hearing Research Institute, University of Michigan, Ann Arbor, Michigan 48109-0506, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.