PMID- 10036259
OWN - NLM
STAT- MEDLINE
DCOM- 19990817
LR  - 20171213
IS  - 0022-3077 (Print)
IS  - 0022-3077 (Linking)
VI  - 81
IP  - 2
DP  - 1999 Feb
TI  - Midbrain combinatorial code for temporal and spectral information in concurrent 
      acoustic signals.
PG  - 552-63
AB  - All vocal species, including humans, often encounter simultaneous (concurrent) 
      vocal signals from conspecifics. To segregate concurrent signals, the auditory 
      system must extract information regarding the individual signals from their 
      summed waveforms. During the breeding season, nesting male midshipman fish 
      (Porichthys notatus) congregate in localized regions of the intertidal zone and 
      produce long-duration (>1 min), multi-harmonic signals ("hums") during courtship 
      of females. The hums of neighboring males often overlap, resulting in acoustic 
      beats with amplitude and phase modulations at the difference frequencies (dFs) 
      between their fundamental frequencies (F0s) and harmonic components. Behavioral 
      studies also show that midshipman can localize a single hum-like tone when 
      presented with a choice between two concurrent tones that originate from separate 
      speakers. A previous study of the neural mechanisms underlying the segregation of 
      concurrent signals demonstrated that midbrain neurons temporally encode a beat's 
      dF through spike synchronization; however, spectral information about at least 
      one of the beat's components is also required for signal segregation. Here we 
      examine the encoding of spectral differences in beat signals by midbrain neurons. 
      The results show that, although the spike rate responses of many neurons are 
      sensitive to the spectral composition of a beat, virtually all midbrain units can 
      encode information about differences in the spectral composition of beat stimuli 
      via their interspike intervals (ISIs) with an equal distribution of ISI spectral 
      sensitivity across the behaviorally relevant dFs. Together, temporal encoding in 
      the midbrain of dF information through spike synchronization and of spectral 
      information through ISI could permit the segregation of concurrent vocal signals.
FAU - Bodnar, D A
AU  - Bodnar DA
AD  - Section of Neurobiology and Behavior, Cornell University, Ithaca, New York 14853, 
      USA.
FAU - Bass, A H
AU  - Bass AH
LA  - eng
GR  - DC-00092/DC/NIDCD NIH HHS/United States
PT  - Journal Article
PT  - Research Support, U.S. Gov't, P.H.S.
PL  - United States
TA  - J Neurophysiol
JT  - Journal of neurophysiology
JID - 0375404
SB  - IM
MH  - *Acoustic Stimulation
MH  - Action Potentials/physiology
MH  - Animals
MH  - Fishes
MH  - Male
MH  - Mesencephalon/*physiology
MH  - Neurons/physiology
MH  - Pitch Discrimination/*physiology
MH  - Sensitivity and Specificity
MH  - Sound Localization/*physiology
MH  - Spectrum Analysis
MH  - Time Factors
EDAT- 1999/02/26 00:00
MHDA- 1999/02/26 00:01
CRDT- 1999/02/26 00:00
PHST- 1999/02/26 00:00 [pubmed]
PHST- 1999/02/26 00:01 [medline]
PHST- 1999/02/26 00:00 [entrez]
AID - 10.1152/jn.1999.81.2.552 [doi]
PST - ppublish
SO  - J Neurophysiol. 1999 Feb;81(2):552-63. doi: 10.1152/jn.1999.81.2.552.