/Users/andrea/_magisterarbeit/korpus/clean/trainkorpus/1/file10.html NN ----------------------------------------- : Home NP Current NP Issue NN New NP Articles NNS Archive NP Submit VV Paper NP Content JJ AlertsPLoSPLoS NP Journals NNS Journal NP Info NP Ed NP Board NP Author NN Info NP Reviewer NN Info NP Contact NP Us NP Help NN Volume NN 1 CD Issue NN 2 CD JULY NP 2005 CD Previous JJ article NN Next JJ article NN SEARCH NN full JJ text NN Advanced NP Search NP Research NP Article NP Theoretical JJ Analysis NN of IN Pre NP Receptor NN Image NN Conditioning NN in IN Weakly NP Electric NP Fish NP Adriana NP Migliaro NP 1 CD , , Angel NP A NP . SENT Caputi NP 2 CD , , Ruben NP Budelli NP 1 CD 1 CD Secci NP n NN Biomatem NP tica NP , , Instituto NP de NP Biolog NP a DT , , Facultad NP de NP Ciencias NP , , Montevideo NP , , Uruguay NP , , 2 CD Departamento NP de NP Neurociencias NP Integrativas NP y NP Computacionales NP , , Instituto NP de NP Investigaciones NP Biol NP gicas NP Clemente NP Estable NP , , Montevideo NP , , Uruguay NP Electroreceptive NP fish NN detect VVP nearby JJ objects NNS by IN processing VVG the DT information NN contained VVN in IN the DT pattern NN of IN electric JJ currents NNS through IN the DT skin NN . SENT The DT distribution NN of IN local JJ transepidermal JJ voltage NN or CC current JJ density NN on IN the DT sensory JJ surface NN of IN the DT fish's JJ skin NN is VBZ the DT electric JJ image NN of IN the DT surrounding VVG environment NN . SENT This DT article NN reports VVZ a DT model NN study NN of IN the DT quantitative JJ effect NN of IN the DT conductance NN of IN the DT internal JJ tissues NNS and CC the DT skin NN on IN electric JJ image NN generation NN in IN Gnathonemus NP petersii NP G NP nther JJR 1862 JJ . SENT Using VVG realistic JJ modelling VVG , , we PP calculated VVD the DT electric JJ image NN of IN a DT metal NN object NN on IN a DT simulated JJ fish NN having VHG different JJ combinations NNS of IN internal JJ tissues NNS and CC skin NN conductances NNS . SENT An DT object NN perturbs VVZ an DT electric JJ field NN as IN if IN it PP were VBD a DT distribution NN of IN electric JJ sources NNS . SENT The DT equivalent JJ distribution NN of IN electric JJ sources NNS is VBZ referred VVN to TO as IN an DT object's JJ imprimence NN . SENT The DT high JJ conductivity NN of IN the DT fish NN body NN lowers VVZ the DT load NN resistance NN of IN a DT given VVN object's NN imprimence NN , , increasing VVG the DT electric JJ image NN . SENT It PP also RB funnels VVZ the DT current JJ generated VVN by IN the DT electric JJ organ NN in IN such PDT a DT way NN that IN the DT field NN and CC the DT imprimence NN of IN objects NNS in IN the DT vicinity NN of IN the DT rostral JJ electric JJ fovea NN are VBP enhanced VVN . SENT Regarding VVG skin NN conductance NN , , our PP$ results NNS show VVP that IN the DT actual JJ value NN is VBZ in IN the DT optimal JJ range NN for IN transcutaneous JJ voltage NN modulation NN by IN nearby JJ objects NNS . SENT This DT result NN suggests VVZ that DT voltage NN is VBZ the DT answer NN to TO the DT long JJ standing NN question NN as RB to TO whether IN current JJ or CC voltage NN is VBZ the DT effective JJ stimulus NN for IN electroreceptors NNS . SENT Our PP$ analysis NN shows VVZ that IN the DT fish NN body NN should MD be VB conceived VVN as IN an DT object NN that WDT interacts VVZ with IN nearby JJ objects NNS , , conditioning NN the DT electric JJ image NN . SENT The DT concept NN of IN imprimence NN can MD be VB extended VVN to TO other JJ sensory JJ systems NNS , , facilitating VVG the DT identification NN of IN features NNS common JJ to TO different JJ perceptual JJ systems NNS . SENT Editor NN . SENT Karl NP J NP . SENT Friston NP , , University NP College NP London NP , , United NP KingdomReceived NP . SENT April NP 4 CD , , 2005 CD . SENT Accepted VVN . SENT June NP 13 CD , , 2005 CD . SENT Published VVN . SENT July NP 15 CD , , 2005 CD DOI NP . SENT 10 CD . SENT 1371 CD journal NN . SENT pcbi NNS . SENT 0010016 CD Copyright NN . SENT 2005 CD Migliaro NP et NP al NP . SENT This DT is VBZ an DT open JJ access NN article NN distributed VVN under IN the DT terms NNS of IN the DT Creative JJ Commons NP Attribution NN License NN , , which WDT permits VVZ unrestricted JJ use NN , , distribution NN , , and CC reproduction NN in IN any DT medium NN , , provided VVD the DT original JJ work NN is VBZ properly RB cited VVN . SENT Abbreviations NNS . SENT EO NP , , electric JJ organ NN . SENT EOD NP , , electric JJ organ NN discharge NN To TO whom WP correspondence NN should MD be VB addressed VVN . SENT E SYM mail NN . SENT angel NN iibce NN . SENT edu NN . SENT uy NP These DT authors NNS contributed VVD equally RB to TO this DT work NN . SENT Citation NP . SENT Migliaro NP A NP , , Caputi NP AA NN , , Budelli NP R NP 2005 CD Theoretical JJ Analysis NN of IN Pre NP Receptor NN Image NN Conditioning NN in IN Weakly NP Electric NP Fish NP . SENT PLoS NP Comp NP Biol NP 1 CD 2 CD . SENT e SYM 16 CD View NN this DT article NN by IN . SENT FiguresPrint NP PDF NP 3058 CD K NP Screen NP PDF NP 339 CD K NP Download NP CitationDownload NP XML NP Options NPS . SENT See VV Articles NNS Citing VVG This DT ArticleE NP mail NN this DT ArticleSend NP Us NP an DT eLetterRead JJ Other JJ eLettersSearch NN PubMed VVN for IN . SENT Adriana NP MigliaroAngel NP A NP . SENT CaputiRuben NP Budelli NP SynopsisThis NP paper NN analyzes VVZ the DT contribution NN of IN the DT body NN and CC skin NN conductance NN of IN weakly JJ electric JJ fish NN in IN shaping VVG the DT electric JJ image NN , , using VVG a DT realistic JJ computational JJ model NN . SENT Object NN recognition NN , , a DT relevant JJ issue NN in IN sensory JJ systems NNS , , is VBZ not RB yet RB fully RB understood VVN . SENT How WRB pre NP receptor NN mechanisms NNS and CC interactions NNS between IN objects NNS shape NN images NNS is VBZ of IN interest NN in IN all DT sensory JJ systems NNS , , leading VVG to TO general JJ concepts NNS and CC a DT specialized JJ jargon NN . SENT The DT authors NNS rescue VV the DT generality NN of IN two CD concepts NNS for IN understanding VVG sensory JJ systems NNS . SENT These DT concepts NNS were VBD introduced VVN early RB in IN electroreception NN research NN . SENT object NN perturbed VVD field NN change NN in IN the DT basal JJ field NN generated VVN by IN the DT presence NN of IN an DT object NN , , and CC imprimence NN equivalent NN sources NNS produced VVN at IN the DT location NN of IN the DT object NN . SENT The DT fish NN body NN is VBZ an DT object NN . SENT generating VVG its PP$ imprimence NN , , modifying VVG the DT basal JJ field NN , , and CC interacting VVG with IN other JJ objects NNS . SENT Analogously RB , , the DT human JJ body NN interferes VVZ , , reflecting VVG light NN or CC sound NN in IN the DT generation NN of IN visual JJ and CC acoustic JJ images NNS . SENT The DT contribution NN of IN internal JJ and CC skin NN conductivities NNS in IN image NN generation NN has VHZ been VBN controversial JJ since IN the DT seminal JJ work NN of IN Lissmann NP and CC Machin NP in IN 1958 CD . SENT We PP show VVP that IN the DT high JJ internal JJ conductance NN of IN the DT fish NN increases VVZ and CC redirects VVZ the DT currents NNS that WDT illuminate VV objects NNS , , increasing VVG and CC shaping VVG the DT electric JJ image NN . SENT Skin NN resistance NN mainly RB influences VVZ image NN magnitude NN . SENT TopSynopsisIntroductionResultsDiscussionMaterials NNS and CC MethodsAcknowledgmentsReferencesIntroductionElectroreceptive JJ fish NN detect VV nearby JJ objects NNS by IN processing VVG the DT information NN contained VVN in IN the DT pattern NN of IN electric JJ currents NNS through IN the DT skin NN . SENT In IN weakly JJ electric JJ fish NN , , these DT currents NNS result NN from IN a DT self NN generated VVD field NN , , produced VVN by IN the DT electric JJ organ NN discharge NN EOD NP . SENT Local JJ transepidermal JJ voltage NN or CC current JJ density NN is VBZ the DT effective JJ stimulus NN for IN electroreceptors NNS . SENT The DT distribution NN of IN voltage NN or CC current JJ on IN the DT sensory JJ surface NN of IN the DT fish's JJ skin NN is VBZ the DT electric JJ image NN of IN the DT surrounding VVG environment NN 1 CD 3 CD . SENT From IN this DT image NN , , the DT brain NN constructs VVZ a DT representation NN of IN the DT external JJ world NN . SENT Therefore RB , , to TO understand VV electrolocation NN it PP is VBZ necessary JJ to TO know VV the DT image NN generation NN strategy NN used VVN by IN electrolocating VVG animals NNS . SENT Theoretical JJ analysis NN of IN image NN generation NN has VHZ yielded VVN realistic JJ models NNS that WDT predict VVP with IN acceptable JJ accuracy NN the DT electrosensory JJ stimulus NN 4 CD 12 CD . SENT One CD general JJ conclusion NN of IN previous JJ reports NNS is VBZ that IN the DT skin NN conductance NN and CC the DT conductivity NN difference NN between IN the DT internal JJ tissues NNS of IN the DT fish NN and CC the DT water NN are VBP the DT main JJ factors NNS shaping VVG the DT electric JJ image NN . SENT the DT seminal JJ paper NN by IN Lissmann NP and CC Machin NP 13 CD started VVD a DT long JJ lasting JJ controversy NN about IN the DT roles NNS of IN these DT factors NNS . SENT Lissmann NP and CC Machin NP argued VVD that IN if IN the DT fish NN has VHZ approximately RB the DT same JJ conductivity NN as IN the DT water NN and CC that IN it PP does VVZ not RB appreciably RB distort VV the DT perturbing VVG field NN i NP . SENT e SYM . SENT , , does VVZ not RB produce VV an DT image NN of IN the DT image NN , , the DT potential JJ distribution NN around IN the DT fish NN due JJ to TO the DT perturbing VVG field NN can MD be VB calculated VVN . SENT However RB , , several JJ reports NNS 3 CD , , 7 CD , , 14 CD have VHP indicated VVN that IN the DT internal JJ conductivity NN of IN freshwater NN fish NN is VBZ high JJ with IN respect NN to TO the DT surrounding VVG water NN , , and CC that IN the DT high JJ conductance NN of IN internal JJ tissues NNS is VBZ critical JJ for IN enhancing VVG the DT local JJ EOD NP field NN as IN well RB as RB for IN generating VVG the DT centre NN surround VVP opposition NN pattern NN that WDT characterizes VVZ electric JJ images NNS and CC that WDT is VBZ coded VVN by IN primary JJ afferents NNS 15 CD . SENT Experimental JJ studies NNS in IN pulse NN gymnotids NNS have VHP confirmed VVN theoretical JJ predictions NNS , , showing VVG that IN the DT high JJ conductivity NN of IN the DT fish NN body NN funnels VVZ the DT self NN generated VVD current JJ to TO the DT perioral JJ region NN , , where WRB an DT electrosensory JJ fovea NN has VHZ been VBN described VVN on IN the DT basis NN of IN electroreceptor NN density NN , , variety NN , , and CC central JJ representation NN 16 CD . SENT This DT funnelling VVG effect NN enhances VVZ the DT stimulus NN at IN the DT foveal JJ region NN . SENT In IN addition NN , , two CD different JJ types NNS of IN skin NN have VHP been VBN described VVN in IN some DT electric JJ fish NN of IN the DT family NN Mormyridae NP . SENT the DT low JJ conductance NN mormyromast NN epithelium NN where WRB electroreceptors NNS are VBP present JJ , , and CC the DT high JJ conductance NN non JJ mormyromast NN epithelium NN where WRB electroreceptors NNS are VBP absent JJ 7 CD , , 17 CD . SENT The DT mormyromast NN epithelium NN is VBZ found VVN on IN the DT head NN in IN front NN of IN the DT gills NNS , , as RB well RB as RB along IN the DT dorsum NN of IN the DT back NN and CC along IN the DT ventral JJ surface NN of IN the DT trunk NN . SENT The DT non JJ mormyromast NN epithelium NN is VBZ found VVN along IN the DT sides NNS of IN the DT trunk NN . SENT This DT heterogeneity NN of IN skin NN conductance NN introduces VVZ another DT factor NN shaping VVG physical JJ electric JJ images NNS . SENT This DT article NN describes VVZ a DT realistic JJ modelling VVG study NN of IN the DT effect NN of IN the DT internal JJ and CC skin NN conductance NN on IN electric JJ image NN generation NN in IN G NP . SENT petersii NNS . SENT We PP have VHP calculated VVN the DT electric JJ image NN of IN a DT metal NN object NN on IN a DT simulated JJ fish NN having VHG different JJ magnitudes NNS of IN conductances NNS for IN internal JJ tissues NNS and CC skin NN . SENT While IN the DT high JJ conductivity NN of IN the DT fish NN body NN enhances VVZ the DT electric JJ image NN by IN a DT combination NN of IN mechanisms NNS , , the DT skin NN conductance NN appears VVZ to TO optimize VV the DT transcutaneous JJ voltage NN modulation NN by IN nearby JJ objects NNS . SENT In IN contrast NN , , transcutaneous JJ current JJ increases NNS monotonically RB with IN skin NN conductivity NN . SENT These DT results NNS suggest VVP that DT transcutaneous JJ voltage NN is VBZ the DT critical JJ proximal JJ stimulus NN for IN electroreceptors NNS . SENT We PP generalize VV two CD concepts NNS . SENT object VV perturbing VVG field NN and CC imprimence NN , , introduced VVN early RB in IN electroreception NN research NN 13 CD , , to TO other JJ sensory JJ systems NNS . SENT An DT object NN perturbs VVZ an DT electric JJ field NN as IN if IN it PP were VBD adding VVG a DT new JJ field NN to TO the DT basal JJ one CD . SENT This DT perturbing VVG field NN can MD be VB considered VVN as IN equivalent NN to TO a DT certain JJ distribution NN of IN electric JJ sources NNS . SENT This DT distribution NN is VBZ referred VVN to TO as IN an DT object's JJ imprimence NN . SENT TopSynopsisIntroductionResultsDiscussionMaterials NNS and CC MethodsAcknowledgmentsReferencesResultsElectric JJ fields NNS and CC images NNS generated VVN by IN metal NN objects NNS were VBD described VVN in IN previous JJ reports NNS reviewed VVN by IN 3 CD . SENT In IN Figure NP 1 CD , , we PP present VVP results NNS obtained VVN with IN a DT realistic JJ fish NN model NN and CC a DT metal NN cube NN , , as IN a DT reference NN for IN the DT following VVG simulations NNS . SENT Figure NN 1 CD A NP shows VVZ the DT basal JJ field NN , , i NP . SENT e SYM . SENT , , the DT field NN generated VVN by IN the DT EOD NP in IN the DT absence NN of IN objects NNS . SENT Since IN all PDT the DT components NNS of IN the DT scene NN are VBP purely RB resistive JJ elements NNS , , the DT electric JJ field NN generated VVN by IN the DT EOD NP has VHZ a DT constant JJ spatial JJ distribution NN and CC thus RB can MD be VB described VVN with IN a DT static JJ analysis NN . SENT Therefore RB , , the DT EOD NP has VHZ been VBN represented VVN by IN a DT DC NP current NN flowing VVG caudal JJ to TO rostral JJ along IN the DT electric JJ organ NN EO NP . SENT The DT isopotential JJ lines NNS run VVP closely RB parallel VV to TO the DT skin NN , , and CC the DT distance NN between IN them PP diminishes VVZ close JJ to TO the DT tip NN of IN the DT barbillon NN , , a DT finger NN like IN extension NN of IN the DT lower JJR lip NN found VVN in IN some DT mormyrid JJ fish NN . SENT This DT indicates VVZ that DT field NN strength NN and CC , , consequently RB , , current JJ magnitudes NNS are VBP larger JJR at IN the DT tip NN of IN the DT barbillon NN , , due JJ to TO edge VV effects NNS . SENT The DT barbillon NN may MD be VB thought VVN of IN as IN an DT electrosensory JJ fovea NN 16 CD , , 17 CD . SENT Figure NN 1 CD B NN shows VVZ the DT distortion NN of IN the DT basal JJ field NN i NP . SENT e SYM . SENT , , the DT object NN perturbing VVG field NN produced VVN by IN the DT presence NN of IN the DT cube NN . SENT This DT distortion NN depends VVZ on IN the DT characteristics NNS of IN the DT object NN and CC the DT basal JJ electric JJ field NN in IN its PP$ neighbourhood NN . SENT The DT object NN perturbing VVG field NN shown VVN in IN Figure NP 1 CD could MD also RB be VB produced VVN by IN a DT set NN of IN dipoles NNS oriented VVN almost RB perpendicular JJ to TO the DT fish NN skin NN at IN the DT point NN closest JJS to IN the DT cube NN object NN imprimence NN 13 CD . SENT The DT electric JJ image NN is VBZ the DT difference NN between IN the DT current JJ densities NNS through IN the DT skin NN in IN the DT presence NN and CC the DT absence NN of IN the DT object NN Figure NP 1 CD C NP . SENT Note NN that IN the DT currents NNS increase VVP positive JJ values NNS in IN the DT skin NN facing VVG the DT cube NN and CC decrease NN in IN a DT larger JJR surrounding JJ region NN , , producing VVG a DT Mexican JJ hat NN type NN image NN that WDT can MD be VB seen VVN in IN the DT graph NN of IN Figure NP 1 CD D NP , , which WDT shows VVZ a DT profile NN of IN the DT image NN along IN a DT line NN on IN the DT sagittal JJ plane NN . SENT Thus RB the DT object NN image NN is VBZ distributed VVN over IN a DT large JJ part NN of IN the DT sensory JJ surface NN and CC is VBZ not RB restricted VVN to TO just RB the DT area NN of IN skin NN facing VVG it PP . SENT Figure NN 1 CD . SENT Image NN Generation NP in IN a DT Fish NP with IN Realistic JJ Internal NP Conductivity NN and CC Homogeneous JJ Highly RB Conductive JJ Skin NN A DT The DT coloured JJ background NN represents VVZ the DT difference NN in IN voltage NN between IN each DT point NN surrounding VVG the DT fish NN and CC an DT infinitely RB distant JJ point NN , , using VVG a DT non JJ linear JJ arctangent JJ colour NN scale NN used VVN to TO highlight VV values NNS close VV to TO zero VV shown VVN in IN the DT colour NN bar NN below IN for IN the DT basal JJ field NN in IN the DT absence NN of IN objects NNS . SENT The DT black JJ line NN shows VVZ the DT zero CD equipotential JJ surface NN , , which WDT is VBZ perpendicular JJ to TO the DT axis NN of IN the DT EO NP equivalent NN dipole NN distribution NN . SENT B SYM A DT similar JJ coloured JJ representation NN shows VVZ the DT perturbing VVG field NN i NP . SENT e SYM . SENT , , the DT field NN in IN the DT presence NN of IN the DT object NN minus IN the DT basal JJ field NN produced VVN by IN a DT metal NN cube NN 1 CD cm NN 3 CD close NN to TO the DT skin NN 0 CD . SENT 5 CD mm NP . SENT The DT black JJ line NN shows VVZ the DT zero CD equipotential JJ surface NN , , which WDT is VBZ perpendicular JJ to TO the DT axis NN of IN the DT object NN equivalent NN dipole NN distribution NN . SENT C NP Electric NP image NN of IN the DT metal NN object NN depicted VVN in IN a DT colour NN map NN on IN the DT modelled VVN realistic JJ fish NN from IN a DT scorci NN view NN . SENT D NP Electric NP image NN along IN the DT intersection NN of IN the DT skin NN with IN the DT sagittal JJ plane NN , , illustrating VVG its PP$ Mexican JJ hat NN profile NN . SENT To TO study VV the DT effect NN of IN the DT skin NN and CC internal JJ conductances NNS on IN the DT generation NN of IN the DT electric JJ image NN , , we PP departed VVD from IN the DT situation NN proposed VVN by IN Lissmann NP and CC Machin NP 1958 CD , , in IN which WDT all DT fish NN tissues NNS have VHP the DT same JJ conductivity NN as IN the DT water NN . SENT Secondly RB , , we PP studied VVD the DT effect NN of IN changing VVG internal JJ conductivity NN , , while IN maintaining VVG a DT skin NN conductance NN that WDT was VBD very RB high JJ and CC therefore RB of IN negligible JJ effect NN . SENT Thirdly RB , , for IN an DT internal JJ conductivity NN similar JJ to TO that DT experimentally RB determined VVN , , we PP studied VVD the DT effect NN of IN changing VVG skin NN conductance NN as IN if IN it PP were VBD uniform JJ along IN the DT fish NN surface NN . SENT Finally RB , , we PP compared VVD results NNS obtained VVN with IN homogeneous JJ skin NN conductances NNS and CC those DT obtained VVN with IN the DT heterogeneous JJ distribution NN of IN the DT skin NN conductances NNS that WDT is VBZ present JJ in IN G NP . SENT petersii NNS . SENT Images NNS as IN a DT Function NN of IN Fish NP Internal NP ConductivityWe NP have VHP proposed VVN that IN the DT low JJ resistivity NN of IN the DT fish NN body NN is VBZ a DT very RB important JJ factor NN for IN the DT shaping VVG of IN the DT electric JJ image NN . SENT To TO assess VV its PP$ contribution NN , , we PP simulated JJ electric JJ images NNS for IN fish NN having VHG a DT high JJ skin NN conductance NN but CC with IN different JJ internal JJ conductivities NNS . SENT We PP first RB modelled VVD a DT fish NN with IN an DT internal JJ conductivity NN equal JJ to TO that DT of IN the DT water NN , , as RB assumed VVN by IN Lissmann NP and CC Machin NP 13 CD . SENT This DT is VBZ described VVN as IN a DT transparent JJ fish NN . SENT In IN this DT case NN , , the DT conductivity NN of IN the DT surrounding VVG medium NN is VBZ homogeneous JJ except IN for IN the DT object NN . SENT Thus RB , , the DT images NNS calculated VVN as IN the DT distribution NN of IN the DT current JJ density NN across IN a DT virtual JJ sensory JJ epithelium NN are VBP the DT perturbing VVG fields NNS at IN the DT surface NN of IN the DT skin NN . SENT The DT basal JJ field NN generated VVN by IN the DT EO NP is VBZ similar JJ to TO the DT field NN of IN a DT dipole NN in IN a DT homogeneous JJ medium NN Figure NP 2 CD A DT . SENT Consequently RB , , and CC in IN contrast NN to TO the DT real JJ situation NN , , the DT isopotentials NNS lines NNS do VVP not RB run VV closely RB parallel JJ to TO the DT skin NN , , and CC the DT field NN at IN the DT tip NN of IN the DT barbillon NN does VVZ not RB show VV an DT edge NN effect NN . SENT Figure NN 2 CD B NN shows VVZ the DT perturbing VVG field NN the DT field NN in IN the DT presence NN of IN the DT object NN minus IN the DT basal JJ field NN produced VVN by IN a DT metal NN cube NN close JJ to TO the DT skin NN . SENT The DT imprimence NN of IN the DT object NN is VBZ equivalent JJ to TO a DT certain JJ distribution NN of IN dipoles NNS located VVN at IN the DT object NN site NN , , no DT longer RBR oriented JJ perpendicular NN to TO the DT skin NN , , in IN contrast NN to TO the DT naturally RB realistic JJ case NN see VVP Figure NP 1 CD B NN . SENT Figure NN 2 CD . SENT Image NN Generation NP in IN a DT Fish NP with IN Internal NP Conductivity NN like IN That DT of IN Water NP and CC with IN a DT Homogeneous JJ Highly RB Conductive JJ SkinThe NP black JJ bars NNS show VVP the DT zero NN equipotential JJ surfaces VVZ as IN in IN Figure NP 1 CD . SENT A DT Basal JJ field NN in IN the DT absence NN of IN objects NNS . SENT B SYM Perturbing VVG field NN produced VVN by IN the DT same JJ scene NN as IN in IN Figure NP 1 CD B NP . SENT C NP Electric NP image NN of IN the DT metal NN object NN depicted VVN in IN a DT colour NN map NN on IN the DT modelled VVN transparent JJ fish NN from IN a DT scorci NN view NN . SENT D NP Electric NP image NN along IN the DT intersection NN of IN the DT skin NN with IN the DT sagittal JJ plane NN . SENT Comparison NN of IN Figures NNS 1 CD and CC 2 CD shows NNS that IN the DT direction NN of IN the DT field NN is VBZ nearly RB parallel JJ to TO the DT transparent JJ fish NN body NN , , and CC nearly RB perpendicular JJ to TO the DT real JJ fish NN body NN . SENT This DT indicates VVZ that IN the DT conductivity NN of IN the DT fish NN body NN distorts VVZ the DT field NN produced VVN by IN the DT EO NP . SENT It PP is VBZ worth JJ noting VVG that IN the DT internal JJ conductivity NN of IN the DT fish NN not RB only RB funnels VVZ the DT current JJ rostrally RB but CC also RB exerts VVZ an DT effect NN on IN the DT field NN direction NN generated VVN at IN the DT object NN location NN . SENT as IN a DT consequence NN , , the DT electric JJ image NN is VBZ more RBR symmetric JJ . SENT Comparison NN of IN image NN profiles NNS along IN a DT sagittal JJ plane NN Figures NNS 1 CD D NP and CC 2 CD D NP shows VVZ an DT enhancement NN of IN the DT image NN amplitude NN produced VVN by IN the DT presence NN of IN the DT fish NN body NN . SENT The DT body NN exerts VVZ this DT effect NN in IN two CD ways NNS . SENT a DT by IN increasing VVG the DT local JJ field NN in IN the DT vicinity NN of IN the DT object NN , , therefore RB increasing VVG the DT perturbing VVG field NN and CC its PP$ imprimence NN , , and CC b LS by IN introducing VVG an DT impedance NN gradient NN at IN the DT site NN of IN the DT sensory JJ surface NN . SENT Previous JJ research NN has VHZ shown VVN that IN the DT amplitude NN of IN the DT image NN generated VVN by IN a DT dipole NN increases VVZ up RP to TO two CD times NNS when WRB the DT fish NN water NN conductivity NN ratio NN increases VVZ 18 CD . SENT To TO test VV this DT mechanism NN , , we PP calculated VVD the DT image NN of IN a DT dipole NN perpendicular NN to TO the DT skin NN of IN a DT transparent JJ fish NN Figure NP 3 CD A DT , , with IN the DT negative JJ pole NN facing VVG the DT skin NN , , comparing VVG it PP with IN the DT image NN of IN the DT same JJ dipole NN on IN a DT fish NN with IN normal JJ internal JJ impedance NN Figure NN 3 CD B NN . SENT While IN the DT waveform NN remains VVZ similar JJ as RB shown VVN in IN the DT current JJ profiles NNS along IN the DT skin NN intersecting VVG with IN the DT sagittal JJ and CC coronal JJ planes NNS , , the DT amplitude NN of IN the DT profile NN for IN the DT realistic JJ fish NN is VBZ twice RB that IN for IN the DT transparent JJ fish NN Figure NP 3 CD C NP . SENT Figure NN 3 CD . SENT The DT Effect NN of IN Internal NP Conductivity NN on IN the DT Image NN Generation NP of IN a DT Dipole NN A DT Electric NP image NN of IN a DT dipole NN placed VVN at IN 0 CD . SENT 5 CD mm NNS from IN a DT transparent JJ fish NN seen VVN from IN a DT scorci NN view NN . SENT the DT modelled VVN dipole NN axis NN is VBZ perpendicular JJ to TO the DT longitudinal JJ axis NN of IN the DT fish NN . SENT B SYM Same JJ scene NN as IN A DT for IN fish NN with IN realistic JJ internal JJ conductivity NN . SENT C NP Electric NP image NN transcutaneous JJ current JJ density NN along IN the DT intersection NN of IN the DT skin NN with IN the DT sagittal JJ plane NN left VVD , , and CC the DT coronal JJ plane NN right NN , , for IN the DT same JJ dipole NN as IN in IN A NP and CC B NP . SENT Red JJ traces NNS show VVP the DT images NNS on IN a DT transparent JJ fish NN , , while IN blue JJ traces NNS correspond VV to TO a DT fish NN with IN realistic JJ internal JJ conductivity NN . SENT Note NN that IN the DT ordinate NN for IN the DT realistic JJ fish NN left VVN is VBZ twice RB that IN for IN the DT transparent JJ fish NN right NN . SENT Figure NN 4 CD A NP shows VVZ the DT normalized VVN electric JJ image NN of IN a DT metal NN cube NN calculated VVN for IN fish NN with IN different JJ body NN conductivities NNS . SENT In IN order NN to TO maintain VV a DT constant JJ electric JJ source NN , , the DT tail NN region NN was VBD modelled VVN as IN an DT independent JJ compartment NN with IN realistic JJ internal JJ conductivity NN . SENT As IN shown VVN in IN the DT normalized VVN images NNS Figure NN 4 CD A DT , , both CC edges NNS shift VVP rostrally RB with IN a DT predominant JJ shift NN of IN the DT rostral JJ border NN , , so RB that IN the DT image NN becomes VVZ wider JJR as IN body NN conductivity NN increases NNS . SENT In IN addition NN , , the DT shape NN of IN the DT profile NN , , which WDT initially RB consists VVZ of IN two CD main JJ deflections NNS one CD caudal JJ positive JJ and CC one CD rostral JJ negative JJ , , becomes VVZ more RBR symmetric JJ , , resembling VVG a DT Mexican JJ hat NN . SENT The DT amplitude NN of IN the DT image NN is VBZ an DT increasing VVG function NN of IN body NN conductance NN Figure NP 4 CD B NP . SENT These DT changes NNS are VBP correlated VVN with IN an DT increase NN in IN the DT magnitude NN and CC a DT change NN in IN the DT direction NN of IN the DT basal JJ field NN around IN the DT object NN . SENT Figure NN 4 CD . SENT The DT Effect NN of IN Internal NP Conductivity NN on IN Electric NP Image NN Generation NP A NP Normalized VVD electric JJ images NNS of IN the DT same JJ metal NN cube NN identical JJ position NN on IN fish NN with IN different JJ internal JJ conductivities NNS . SENT Red NP . SENT 16 CD . SENT 5 CD Scm NP 1 CD the DT same JJ as IN water NN conductivity NN , , cyan NN . SENT 165 CD Scm NP 1 CD , , blue JJ . SENT 1 CD , , 650 CD Scm NP 1 CD , , black JJ . SENT 16 CD , , 500 CD Scm NP 1 CD normal JJ conductivity NN , , magenta NN . SENT 165 CD , , 000 CD Scm NP 1 CD . SENT The DT skin NN is VBZ modelled VVN for IN all DT cases NNS , , with IN a DT homogeneous JJ conductivity NN of IN 500 CD , , 000 CD Scm NP 1 CD . SENT The DT dashed VVN line NN shows VVZ the DT case NN of IN a DT fish NN with IN realistic JJ internal JJ conductivity NN and CC skin NN conductivity NN distribution NN . SENT rl NP , , realistic JJ internal JJ conductivity NN . SENT rlh NP , , realistic JJ internal JJ conductivity NN , , heterogeneous JJ skin NN distribution NN . SENT B NP Peak NP amplitude NN of IN the DT electric JJ image NN of IN a DT metal NN cube NN 1 CD cm NN 3 LS placed VVN at IN 0 CD . SENT 5 CD mm NNS from IN the DT fish NN , , as IN a DT function NN of IN body NN internal JJ conductivity NN . SENT The DT difference NN in IN the DT peak NN amplitude NN of IN the DT electric JJ image NN corresponding JJ to TO the DT realistic JJ internal JJ conductivity NN fish NN shown VVN in IN this DT figure NN and CC that IN shown VVN in IN Figure NP 1 CD is VBZ due JJ to TO the DT use NN of IN two CD compartment NN bodies NNS see VVP Materials NNS and CC Methods NNS . SENT The DT Effect NN of IN Skin NN ConductanceTo NP assess VVP the DT contribution NN of IN the DT skin NN to TO image NN formation NN , , we PP studied VVD the DT effect NN of IN different JJ uniform JJ skin NN conductances NNS for IN a DT fish NN with IN normal JJ internal JJ conductivity NN . SENT For IN very RB low JJ skin NN conductivity NN , , the DT transepithelial JJ currents NNS produced VVN by IN the DT EO NP are VBP negligible JJ Figure NP 5 CD . SENT the DT current JJ short JJ circuits NNS inside IN the DT fish NN because IN it PP cannot NN flow NN through IN the DT skin NN . SENT The DT transepithelial JJ current JJ increases NNS with IN the DT skin NN conductivity NN , , approaching VVG an DT asymptotic JJ value NN red NN trace VV in IN Figure NP 5 CD A NP and CC 5 CD C NP . SENT Since IN transcutaneous JJ voltage NN is VBZ the DT quotient NN of IN the DT current JJ density NN divided VVN by IN skin NN conductance NN , , voltage NN increases NNS differently RB with IN skin NN conductance NN , , rising VVG to TO a DT maximum NN and CC then RB decreasing VVG blue JJ trace NN in IN Figure NP 5 CD B NP and CC 5 CD C NP . SENT The DT value NN of IN skin NN conductance NN at IN which WDT voltage NN reaches VVZ a DT maximum NN , , 100 CD Scm NP 2 CD , , is VBZ close JJ to TO the DT actual JJ measured JJ value NN for IN the DT mormyromast NN epithelium NN . SENT This DT suggests VVZ that DT electroreceptors NNS operate VVP in IN a DT voltage NN detection NN mode NN rather RB than IN in IN a DT current JJ detection NN mode NN . SENT The DT normalized VVN curves NNS in IN Figure NP 5 CD D NP show NN that IN the DT image NN is VBZ smoother JJR and CC wider JJR as IN the DT skin NN conductance NN decreases NNS . SENT Continuous JJ traces NNS correspond VV to TO uniform JJ skin NN conductances NNS , , where WRB the DT cyan JJ one NN is VBZ the DT closest JJS to TO the DT mormyromast NN epithelium NN value NN . SENT Realistic JJ electric JJ images NNS were VBD calculated VVN as IN a DT reference NN , , using VVG the DT distribution NN of IN conductivities NNS determined VVN experimentally RB dotted VVD traces NNS 7 CD . SENT Figure NN 5 CD . SENT The DT Effect NN of IN Skin NN Conductivity NN on IN Electric NP Image NN Generation NP A DT Transcutaneous JJ current JJ density NN electric JJ image NN of IN a DT metal NN cube NN 1 CD cm NN 3 LS placed VVN at IN 0 CD . SENT 5 CD mm NNS from IN the DT skin NN , , modelled VVN on IN skin NN with IN different JJ conductivities NNS . SENT Red NP . SENT 10 CD Scm NP 2 CD , , cyan NN . SENT 100 CD Scm NP 2 CD similar JJ to TO mormyromast NN epithelium NN , , blue JJ . SENT 1 CD , , 000 CD Scm NP 2 CD , , black JJ . SENT 10 CD , , 000 CD Scm NP 2 CD , , magenta NN . SENT 100 CD , , 000 CD Scm NP 2 CD . SENT All PDT these DT fish NN have VH an DT internal JJ conductivity NN of IN 3 CD , , 300 CD Scm NP 1 CD . SENT Dashed VVN line NN shows VVZ the DT case NN of IN a DT fish NN with IN realistic JJ internal JJ conductivity NN and CC skin NN conductivity NN distribution NN . SENT B SYM Transcutaneous JJ voltage NN calculated VVN from IN the DT transcutaneous JJ current JJ densities NNS shown VVN in IN A DT , , using VVG the DT same JJ colour NN code NN . SENT C SYM Current JJ peak NN right NN axis NN , , red JJ trace NN and CC voltage NN peak NN left VVD axis NN , , blue JJ trace NN as IN a DT function NN of IN skin NN conductivity NN for IN fish NN with IN homogeneous JJ skin NN . SENT D SYM Normalized VVN plot NN for IN B NP , , using VVG same JJ colour NN code NN . SENT mel NN , , mormyromast NN epithelium NN like IN conductivity NN . SENT rlh NP , , realistic JJ internal JJ conductivity NN , , heterogeneous JJ skin NN distribution NN . SENT TopSynopsisIntroductionResultsDiscussionMaterials NNS and CC MethodsAcknowledgmentsReferencesDiscussionAnimals NNS extract VV information NN from IN the DT environment NN and CC from IN their PP$ own JJ bodies NNS by IN analyzing VVG changes NNS in IN the DT patterns NNS of IN energy NN impinging VVG on IN their PP$ sensory JJ surfaces VVZ . SENT In IN that DT sense NN , , it PP can MD be VB affirmed VVD that IN to TO see VV is VBZ to TO reconstruct VV visual JJ scenes NNS from IN a DT light JJ pattern NN on IN the DT retina NN or CC to TO hear VV is VBZ to TO extract VV auditory JJ scenes NNS from IN sound JJ patterns NNS at IN the DT cochlea NN 19 CD . SENT Similarly RB , , electric JJ sensing VVG is VBZ to TO reconstruct VV electric JJ scenes NNS from IN the DT pattern NN of IN electric JJ currents NNS through IN the DT skin NN . SENT In IN electrosensory JJ perception NN , , each DT object NN generates VVZ a DT signal NN that IN results NNS from IN the DT deformation NN that IN its PP$ presence NN causes VVZ in IN an DT electric JJ field NN . SENT This DT deformation NN is VBZ a DT virtual JJ field NN , , called VVD object NN perturbing VVG field NN by IN Lissmann NP and CC Machin NP 13 CD . SENT The DT object NN perturbing VVG field NN is VBZ not RB directly RB measurable JJ , , but CC computable JJ as IN the DT electric JJ field NN in IN the DT presence NN of IN the DT object NN minus IN the DT electric JJ field NN in IN its PP$ absence NN , , also RB called VVN basal JJ field NN . SENT As IN any DT electric JJ field NN , , the DT object NN perturbing VVG field NN can MD be VB considered VVN as IN caused VVN by IN an DT electric JJ source NN , , which WDT is VBZ equivalent JJ to TO the DT presence NN of IN the DT object NN . SENT The DT imprimence NN of IN an DT object NN , , an DT expression NN also RB coined VVN by IN Lissmann NP and CC Machin NP 13 CD referring VVG to TO the DT electric JJ sources NNS equivalent JJ to TO the DT object NN , , not RB only RB generates VVZ an DT image NN but CC also RB a DT change NN in IN the DT field NN that WDT interacts VVZ with IN other JJ objects NNS . SENT Thus RB , , the DT effect NN of IN a DT given VVN object NN not RB only RB generates VVZ its PP$ own JJ image NN but CC also RB modifies VVZ the DT images NNS of IN other JJ objects NNS 10 CD . SENT There EX are VBP theoretical JJ and CC experimental JJ reasons NNS indicating VVG that IN the DT fish NN body NN is VBZ also RB an DT object NN , , and CC that IN this DT is VBZ of IN particular JJ importance NN since IN it PP is VBZ an DT object NN that WDT is VBZ always RB present JJ as IN a DT major JJ determinant NN of IN sensory JJ imaging NN 5 CD , , 7 CD , , 18 CD , , 20 CD . SENT This DT leads VVZ to TO the DT proposition NN that IN the DT fish NN body NN , , by IN its PP$ presence NN and CC movements NNS , , constitutes VVZ a DT critical JJ pre NP receptor NN mechanism NN that IN conditions NNS sensory JJ signals NNS 16 CD , , 21 CD . SENT We PP , , therefore RB , , discuss VV here RB the DT effect NN of IN relevant JJ components NNS of IN the DT fish's JJ body NN on IN image NN generation NN . SENT The DT Effect NN of IN the DT Fish's NP Internal NP ConductivityThe NP imaging NN process NN consists VVZ of IN two CD steps NNS . SENT imprimence NN generation NN yellow JJ boxes NNS in IN Figure NP 6 CD and CC image NN generation NN purple JJ boxes NNS in IN Figure NP 6 CD . SENT The DT simplest JJS example NN occurs VVZ in IN a DT transparent JJ fish NN , , isoconductive JJ with IN water NN . SENT The DT electric JJ image NN green JJ arrow NN in IN Figure NP 6 CD A DT is VBZ the DT difference NN between IN the DT electrosensory JJ stimulus NN generated VVN in IN the DT presence NN of IN an DT object NN light NN blue JJ arrow NN in IN Figure NP 6 CD A NP and CC the DT electrosensory JJ stimulus NN generated VVN in IN the DT absence NN of IN that WDT object VVP dark JJ blue JJ arrow NN in IN Figure NP 6 CD A NP . SENT The DT latter NN is VBZ referred VVN to TO as IN the DT basal JJ stimulus NN because IN it PP is VBZ caused VVN by IN the DT basal JJ field NN . SENT Since RB , , in IN the DT case NN of IN the DT transparent JJ fish NN , , the DT basal JJ field NN is VBZ not RB distorted VVN by IN the DT fish NN body NN , , the DT electric JJ image NN results NNS from IN the DT projection NN on IN the DT skin NN of IN a DT field NN perturbation NN induced VVD only RB as IN a DT consequence NN of IN interaction NN of IN the DT object NN with IN the DT basal JJ field NN green JJ arrows NNS in IN Figure NP 6 CD A DT . SENT Then RB , , in IN a DT transparent JJ fish NN , , image NN formation NN can MD be VB described VVN as IN a DT simple JJ process NN consisting VVG of IN two CD steps NNS . SENT a DT the DT generation NN of IN a DT field NN by IN the DT EO NP and CC b LS the DT deformation NN of IN this DT field NN by IN the DT presence NN of IN the DT object NN . SENT Figure NN 6 CD . SENT Schematic JJ Representation NN of IN Electric NP Image NN GenerationFirst NP row NN , , generation NN of IN stimulation NN in IN the DT presence NN of IN the DT object NN . SENT second JJ row NN , , basal JJ stimulation NN in IN the DT absence NN of IN objects NNS . SENT third JJ row NN , , sensory JJ image NN . SENT A DT Fish NP with IN water NN like IN internal JJ conductivity NN . SENT Imprimence NN generation NN yellow JJ boxes NNS precedes VVZ image NN generation NN purple JJ boxes NNS . SENT A DT field NN perturbation NN green JJ arrows NNS is VBZ induced VVN as IN a DT consequence NN of IN the DT object NN interaction NN with IN the DT basal JJ field NN dark JJ blue JJ arrows NNS . SENT The DT electric JJ image NN is VBZ the DT difference NN between IN the DT perturbing VVG light JJ blue JJ arrow NN and CC the DT basal JJ fields NNS at IN the DT skin NN . SENT B NP Fish NP with IN realistic JJ internal JJ conductivity NN . SENT The DT interaction NN of IN the DT body NN with IN the DT field NN perturbed VVD by IN the DT object NN red JJ arrows NNS introduces VVZ another DT component NN orange NN arrow NN to TO the DT electrosensory JJ stimulus NN magenta NN arrow NN . SENT The DT electric JJ image NN yellow JJ arrow NN is VBZ the DT electrosensory JJ stimulus NN minus IN the DT basal JJ field NN blue JJ arrow NN , , representing VVG the DT sum NN of IN the DT effects NNS of IN the DT fish NN body NN and CC the DT object NN in IN the DT presence NN of IN each DT other JJ . SENT See VV Discussion NN for IN explanation NN . SENT However RB , , in IN nature NN , , the DT basal JJ field NN is VBZ different JJ from IN that DT produced VVN by IN the DT EO NP in IN a DT homogeneous JJ medium NN , , because IN it PP is VBZ affected VVN by IN the DT inextricable JJ presence NN of IN the DT fish NN body NN . SENT Similarly RB , , the DT object NN perturbing VVG field NN is VBZ also RB affected VVN by IN the DT fish's JJ body NN . SENT This DT interaction NN red JJ arrows NNS produces VVZ two CD extra JJ components NNS that WDT add VVP to TO the DT basal JJ electrosensory JJ stimulus NN dark JJ blue JJ arrow NN . SENT the DT perturbing VVG field NN of IN the DT object NN green JJ arrow NN and CC the DT perturbing VVG field NN of IN the DT fish NN body NN orange NN arrow NN . SENT This DT resulting VVG field NN acting VVG on IN the DT skin NN is VBZ the DT electrosensory JJ stimulus NN magenta NN arrow NN . SENT To TO calculate VV the DT electric JJ image NN , , we PP subtracted VVD the DT effect NN of IN the DT basal JJ stimulus NN fish NN body NN alone RB , , blue JJ arrow NN . SENT Thus RB , , the DT electric JJ image NN yellow JJ arrow NN results NNS from IN the DT addition NN of IN the DT perturbing VVG field NN of IN the DT fish's JJ body NN in IN the DT presence NN of IN the DT object NN orange NN arrow NN plus CC the DT perturbing VVG field NN of IN the DT object NN in IN the DT presence NN of IN the DT fish's JJ body NN green JJ arrow NN . SENT When WRB the DT object NN is VBZ large JJ enough RB and CC surrounds VVZ the DT fish NN , , its PP$ effect NN becomes VVZ very RB important JJ , , having VHG a DT strong JJ influence NN on IN the DT overall JJ pattern NN of IN current JJ flow NN . SENT This DT is VBZ the DT case NN when WRB the DT fish NN chooses VVZ to TO stay VV in IN confined VVN spaces NNS that WDT are VBP frequently RB its PP$ preference NN in IN the DT natural JJ habitat NN , , or CC in IN the DT tube NN shaped VVN shelters NNS commonly RB used VVN in IN captivity NN . SENT The DT fish's NNS positioning NN of IN its PP$ body NN in IN this DT manner NN strongly RB affects VVZ the DT electric JJ images NNS of IN objects NNS and CC electrosensory JJ responses NNS 22 CD . SENT When WRB the DT object NN is VBZ relatively RB small JJ or CC far RB from IN the DT fish NN body NN , , the DT loop NN between IN the DT object NN and CC the DT fish NN body NN opens VVZ , , because IN the DT influence NN of IN the DT field NN of IN the DT object NN on IN the DT fish NN body NN becomes VVZ negligible JJ compared VVN to TO the DT basal JJ field NN . SENT Consequently RB , , the DT scheme NN of IN image NN generation NN is VBZ the DT same JJ as RB in IN the DT case NN of IN the DT transparent JJ fish NN . SENT However RB , , the DT basal JJ field NN illuminating VVG the DT object NN is VBZ different JJ than IN that DT in IN the DT case NN of IN a DT transparent JJ fish NN and CC so RB is VBZ the DT image NN . SENT The DT Effect NN of IN Skin NN ConductivityThe NP skin NN conductance NN is VBZ the DT other JJ important JJ factor NN shaping VVG the DT electric JJ image NN . SENT A DT homogeneous JJ decrease NN of IN the DT skin NN conductance NN causes NNS . SENT a DT a DT decrease NN of IN the DT transepithelial JJ current JJ density NN , , b LS an DT increase NN of IN the DT transepithelial JJ voltage NN up RB to TO a DT maximum NN at IN the DT range NN of IN natural JJ skin NN conductivity NN , , c LS a DT decrease NN of IN the DT relative JJ slope NN of IN the DT flanks NNS of IN the DT image NN , , and CC d LS an DT increase NN of IN the DT centre NN region NN of IN the DT Mexican JJ hat NN profile NN . SENT For IN measuring VVG electrosensory JJ stimulus NN , , either CC local JJ field NN equivalent NN to TO current JJ flow NN or CC transcutaneous JJ voltage NN has VHZ often RB been VBN used VVN indiscriminately RB 1 CD , , 20 CD , , 23 CD . SENT However RB , , our PP$ results NNS indicate VVP that DT current JJ density NN and CC voltage NN are VBP not RB equivalent JJ stimuli NNS . SENT The DT transepithelial JJ change NN in IN voltage NN caused VVN by IN an DT object NN is VBZ the DT maximum NN within IN the DT range NN of IN skin NN conductances NNS that WDT are VBP actually RB measured VVN in IN the DT mormyromast NN epithelium NN of IN G NP . SENT petersii NNS 70 CD 500 CD Scm NP 2 CD 7 CD , , suggesting VVG that IN the DT low JJ conductance NN observed VVD in IN the DT mormyromast NN epithelium NN might MD be VB an DT adaptation NN for IN optimizing VVG voltage NN sensing VVG . SENT This DT low JJ conductance NN of IN the DT mormyromast NN epithelium NN is VBZ caused VVN by IN a DT thin JJ layer NN of IN tightly RB packed VVN epithelial JJ cells NNS 24 CD , , which WDT makes VVZ the DT mormyromast NN epithelium NN up RB to TO ten CD times NNS more RBR resistant JJ than IN the DT non JJ mormyromast NN epithelium NN 7 CD . SENT If IN receptors NNS electrically RB shunt VV their PP$ low JJ conductance NN non JJ sensitive JJ surroundings NN , , transcutaneous JJ voltage NN could MD be VB considered VVN to TO be VB the DT meaningful JJ parameter NN of IN the DT stimulus NN . SENT Experimental JJ measurements NNS testing VVG this DT hypothesis NN should MD be VB done VVN . SENT Our PP$ study NN also RB shows VVZ a DT consistent JJ decrease NN in IN the DT relative JJ slope NN of IN the DT flanks NNS of IN the DT image NN and CC an DT increase NN in IN the DT centre NN region NN of IN the DT Mexican JJ hat NN profile NN with IN increasing VVG skin NN resistance NN see VVP Figure NP 5 CD D NP . SENT In IN this DT study NN , , restricted VVN to TO single JJ conductive JJ objects NNS close JJ to TO the DT skin NN , , these DT changes NNS are VBP rather RB small JJ , , indicating VVG that IN the DT main JJ factor NN for IN determining VVG object NN image NN shape NN is VBZ the DT internal JJ conductance NN of IN the DT fish NN body NN . SENT The DT Generality NN of IN the DT Concepts NNS of IN Object NN Perturbing VVG Field NP and CC ImprimenceObject NP recognition NN is VBZ an DT important JJ issue NN in IN all DT sensory JJ systems NNS including VVG electrical JJ perception NN , , but CC it PP is VBZ not RB well RB understood VVN . SENT The DT comparative JJ study NN of IN different JJ sensory JJ systems NNS leads VVZ to TO general JJ concepts NNS and CC a DT language NN that WDT could MD potentially RB be VB shared VVN by IN researchers NNS in IN different JJ systems NNS . SENT In IN this DT paper NN , , we PP focus VVP on IN peripheral JJ imaging NN mechanisms NNS , , a DT subject NN common JJ to TO sensory JJ systems NNS . SENT We PP focus VVP in IN particular JJ on IN the DT way NN in IN which WDT pre NP receptor NN mechanisms NNS and CC interactions NNS between IN different JJ objects NNS in IN a DT given VVN scene NN shape VV the DT image NN . SENT We PP emphasize VVP two CD concepts NNS that WDT were VBD introduced VVN early RB on IN in IN electroreception NN research NN 13 CD . SENT object VV perturbing VVG field NN and CC imprimence NN . SENT An DT object NN perturbs VVZ an DT electric JJ field NN as IN if IN it PP were VBD a DT distribution NN of IN electric JJ sources NNS . SENT The DT equivalent JJ distribution NN of IN electric JJ sources NNS is VBZ referred VVN to TO as IN an DT object's JJ imprimence NN . SENT Object VV perturbing VVG field NN is VBZ a DT concept NN that WDT relates VVZ to TO reflections NNS and CC refractances NNS in IN vision NN , , echoes NNS in IN audition NN , , etc FW . SENT In IN the DT same JJ way NN that IN objects NNS of IN different JJ impedance NN than IN the DT water NN modify VV an DT electric JJ field NN , , objects NNS in IN a DT visual JJ scene NN modify VV the DT illumination NN . SENT Similarly RB , , echoes NNS and CC resonances NNS produced VVN by IN objects NNS modify VV the DT distribution NN of IN sound NN in IN an DT auditory JJ scene NN . SENT For IN example NN , , the DT sound NN of IN a DT pulsed VVN string NN on IN a DT guitar NN is VBZ greatly RB modified VVN by IN the DT resonance NN of IN the DT box NN , , giving VVG the DT sound NN a DT characteristic JJ timbre NN . SENT The DT concept NN of IN imprimence NN can MD be VB extended VVN in IN the DT same JJ way NN . SENT Objects NNS producing VVG reflexions NNS , , refractances NNS , , echoes NNS , , and CC resonances NNS can MD be VB considered VVN new JJ sources NNS of IN energy NN . SENT The DT imprimence NN produced VVN by IN the DT animal's JJ own JJ body NN acts NNS as IN a DT pre NP receptor NN mechanism NN . SENT The DT fish NN body NN can MD be VB considered VVN as IN an DT object NN that WDT interacts VVZ with IN other JJ objects NNS in IN the DT scene NN , , generating VVG an DT imprimence NN that IN through IN the DT perturbing VVG field NN modifies VVZ the DT basal JJ field NN of IN the DT scene NN and CC , , consequently RB , , the DT imprimence NN of IN the DT other JJ objects NNS . SENT Many JJ species NNS of IN fish NN including VVG Mormyrids NNS hear VVP underwater JJ due JJ to TO the DT imprimence NN produced VVN by IN air NN filled VVN sacs NNS such JJ as IN the DT swimbladder NN 25 CD . SENT In IN a DT less RBR fundamental JJ way NN , , our PP$ body NN changes VVZ the DT visual JJ image NN by IN interfering VVG with IN and CC reflecting VVG light NN , , modifying VVG the DT images NNS of IN nearby JJ objects NNS . SENT In IN addition NN , , the DT interactions NNS between IN objects NNS and CC the DT perturbations NNS of IN the DT fields NNS by IN the DT imprimences NNS of IN other JJ objects NNS are VBP used VVN to TO extract VV information NN from IN a DT scene NN . SENT For IN example NN , , the DT imprimence NN of IN the DT external JJ ear NN modifies VVZ the DT incoming JJ sound NN , , allowing VVG for IN the DT computation NN of IN the DT altitude NN of IN a DT source NN 26 CD . SENT Animal NN senses NNS explore VVP nature NN using VVG a DT limited JJ number NN of IN types NNS of IN energy NN and CC receptors NNS with IN limited JJ dynamic JJ ranges NNS . SENT This DT constrains VVZ and CC conditions NNS the DT representation NN of IN external JJ reality NN according VVG to TO the DT capabilities NNS of IN each DT animal NN . SENT Humans NNS circumvent VV these DT limitations NNS by IN creating VVG artificial JJ systems NNS , , such JJ as IN radar NN or CC sonar NN , , which WDT expand VVP the DT repertoire NN of IN representable JJ qualities NNS of IN objects NNS . SENT The DT concepts NNS of IN imprimence NN and CC perturbing VVG field NN may MD be VB applied VVN to TO the DT design NN of IN artificial JJ sensory JJ systems NNS . SENT It PP is VBZ a DT common JJ practice NN to TO deal VV with IN interactions NNS between IN objects NNS and CC the DT perturbations NNS of IN the DT fields NNS by IN the DT imprimences NNS of IN other JJ objects NNS as IN undesirable JJ interference NN . SENT Nevertheless RB , , evolution NN has VHZ developed VVN neural JJ operations NNS that WDT use VVP images NNS resulting VVG from IN object NN interferences NNS as IN a DT source NN of IN information NN , , in IN some DT cases NNS using VVG this DT to TO infer VV object NN attributes NNS . SENT In IN these DT cases NNS , , interference NN between IN objects NNS may MD increase VV the DT amount NN of IN available JJ information NN contained VVN in IN the DT image NN . SENT Development NN of IN the DT theory NN of IN peripheral JJ imaging NN is VBZ a DT necessary JJ step NN for IN the DT design NN of IN computational JJ procedures NNS , , allowing VVG the DT extraction NN of IN a DT larger JJR amount NN of IN information NN from IN the DT same JJ signals NNS . SENT ConclusionsThe NP electric JJ image NN of IN an DT object NN results NNS from IN the DT projection NN on IN the DT skin NN of IN a DT virtual JJ field NN caused VVN by IN the DT presence NN of IN an DT object NN , , in IN a DT given VVN electrosensory JJ scene NN . SENT The DT fish's JJ large JJ internal JJ conductance NN compared VVN with IN water NN causes VVZ a DT rostral JJ funnelling VVG of IN the DT current JJ . SENT This DT leads VVZ to TO an DT increase NN in IN the DT imprimence NN of IN objects NNS close JJ to TO the DT rostral JJ regions NNS of IN the DT fish NN and CC , , consequently RB , , to TO an DT increase NN in IN the DT amplitude NN of IN their PP$ images NNS . SENT The DT large JJ difference NN in IN conductivity NN between IN the DT inside JJ and CC outside JJ of IN the DT fish NN forces VVZ the DT field NN to TO be VB almost RB perpendicular JJ to TO the DT sensory JJ surface NN and CC , , consequently RB , , makes VVZ the DT shape NN of IN the DT image NN more RBR symmetrical JJ . SENT An DT object NN modifies VVZ the DT field NN of IN other JJ objects NNS immersed VVN in IN the DT same JJ global JJ field NN . SENT The DT fish NN body NN itself PP is VBZ a DT major JJ object NN , , inherent JJ to TO the DT process NN of IN image NN generation NN . SENT Thus RB , , a DT global JJ field NN results NNS from IN the DT reciprocal JJ interaction NN between IN the DT fish NN body NN and CC nearby JJ objects NNS . SENT The DT conductance NN of IN the DT skin NN changes VVZ the DT shape NN of IN the DT image NN only RB slightly RB , , but CC drives VVZ the DT amplitude NN considered VVN as IN the DT distribution NN of IN transepithelial JJ voltages NNS close JJ to TO its PP$ maximum NN , , for IN a DT given VVN set NN of IN other JJ electrical JJ parameters NNS . SENT This DT result NN suggests VVZ that IN the DT high JJ resistance NN of IN the DT mormyromast NN surface NN , , a DT property NN conferred VVD by IN a DT thin JJ layer NN of IN tightly RB packed VVN epithelial JJ cells NNS , , may MD serve VV to TO optimize VV object NN images NNS . SENT The DT use NN of IN a DT realistic JJ computational JJ model NN has VHZ allowed VVN us PP to TO settle VV the DT controversy NN about IN the DT relative JJ importance NN of IN the DT internal JJ and CC skin NN conductivities NNS in IN the DT determination NN of IN the DT magnitude NN and CC shape NN of IN the DT electric JJ image NN , , an DT issue NN that WDT has VHZ been VBN debated VVN since IN the DT seminal JJ paper NN by IN Lissmann NP and CC Machin NP 13 CD . SENT We PP propose VVP that IN the DT concepts NNS of IN perturbing VVG field NN and CC imprimence NN 13 CD may MD be VB usefully RB applied VVN to TO the DT analysis NN of IN other JJ sensory JJ systems NNS and CC the DT design NN of IN artificial JJ ones NNS . SENT TopSynopsisIntroductionResultsDiscussionMaterials NP and CC MethodsAcknowledgmentsReferencesMaterials NP and CC MethodsThe NP model NN . SENT Simulations NNS were VBD run VVN using VVG a DT program NN written VVN to TO simulate VV the DT electric JJ image NN in IN weakly JJ electric JJ fish NN i NP . SENT e SYM . SENT , , the DT currents NNS through IN the DT fish NN skin NN , , which WDT uses VVZ the DT Boundary NP Element NN Method NN BEM NP 27 CD , , as RB proposed VVN by IN Assad NP 4 CD , , and CC has VHZ been VBN described VVN previously RB 10 CD , , 28 CD . SENT This DT program NN allows VVZ the DT determination NN of IN the DT electric JJ field NN and CC the DT electrosensory JJ image NN in IN a DT given VVN environment NN scene NN , , calculating VVG the DT currents NNS through IN the DT skin NN . SENT A DT scene NN may MD include VV objects NNS other JJ than IN the DT fish NN of IN different JJ conductivity NN , , shape NN , , and CC size NN , , and CC is VBZ defined VVN by IN setting VVG the DT geometry NN and CC location NN of IN one CD or CC more JJR electric JJ fish NN and CC objects NNS . SENT Water NN , , internal JJ , , and CC skin NN conductivities NNS can MD be VB specified VVN as IN required VVN . SENT When WRB the DT skin NN conductivity NN is VBZ not RB homogeneous JJ , , different JJ regions NNS can MD be VB defined VVN using VVG a DT graphic JJ interface NN . SENT Complex JJ shapes NNS , , including VVG the DT fish NN body NN , , are VBP approximated VVN by IN a DT surface NN composed VVN by IN triangles NNS . SENT Although IN the DT fish NN shape NN is VBZ kept VVN constant JJ throughout IN this DT article NN , , the DT model NN allows VVZ its PP$ modification NN if IN required VVN . SENT Once RB the DT scene NN is VBZ determined VVN , , the DT potentials NNS and CC current JJ densities NNS through IN the DT skin NN of IN the DT fish NN and CC through IN the DT objects NNS are VBP calculated VVN . SENT The DT graphic JJ presentations NNS were VBD made VVN by IN Matlab NP standard JJ subroutines NNS . SENT Changes NNS in IN internal JJ conductivity NN and CC skin NN conductance NN . SENT We PP studied VVD the DT effect NN of IN the DT skin NN and CC internal JJ conductivity NN on IN the DT electric JJ image NN in IN the DT presence NN of IN a DT metallic JJ high JJ conductance NN cube NN placed VVD symmetrically RB to TO the DT sagittal JJ plane NN and CC facing VVG the DT dorsal JJ skin NN 0 CD . SENT 5 CD mm NNS away RB . SENT Water NN conductivity NN was VBD kept VVN at IN 16 CD . SENT 5 CD Scm NP 1 CD . SENT To TO assess VV the DT influence NN of IN the DT internal JJ conductivity NN of IN the DT fish NN body NN , , different JJ values NNS ranging VVG from IN that DT equal JJ to TO surrounding VVG water NN conductivity NN in IN which WDT case NN the DT fish NN may MD be VB considered VVN transparent JJ to TO 16 CD , , 500 CD Scm NP 1 CD were VBD examined VVN , , including VVG the DT value NN experimentally RB determined VVD 3 CD , , 300 CD Scm NP 1 CD . SENT In IN order NN to TO maintain VV a DT constant JJ electric JJ source NN , , tail NN and CC body NN regions NNS were VBD modelled VVN as IN independent JJ compartments NNS , , maintaining VVG the DT tail NN with IN a DT realistic JJ internal JJ conductivity NN while IN applying VVG different JJ values NNS for IN the DT body NN . SENT In IN these DT cases NNS , , the DT conductance NN across IN the DT model NN skin NN was VBD set VVN low JJ enough RB to TO be VB considered VVN irrelevant JJ . SENT To TO study VV the DT influence NN of IN the DT skin NN conductance NN , , we PP explored VVD the DT effect NN of IN different JJ skins NNS with IN homogeneously RB distributed VVN conductances NNS ranging VVG from IN 10 CD 100 CD , , 000 CD Scm NP 2 CD and CC a DT natural JJ like JJ skin NN with IN heterogeneous JJ conductance NN distribution NN . SENT The DT internal JJ conductivity NN in IN this DT case NN was VBD close JJ to TO that DT experimentally RB determined VVN 3 CD , , 300 CD Scm NP 1 CD . SENT Two CD singular JJ conditions NNS were VBD used VVN for IN comparison NN purposes NNS . SENT a DT when WRB the DT fish NN model NN has VHZ experimentally RB determined VVN conductances NNS where WRB the DT fish NN body NN exerts VVZ its PP$ normal JJ effect NN on IN the DT electric JJ image NN . SENT and CC b NN when WRB it PP has VHZ water NN like IN conductances NNS i NP . SENT e SYM . SENT , , where WRB the DT fish NN body NN exerts VVZ no DT effect NN on IN the DT electric JJ image NN . SENT TopSynopsisIntroductionResultsDiscussionMaterials NP and CC MethodsAcknowledgmentsReferencesAcknowledgmentsThe NP authors NNS would MD like VV to TO thank VV Dr NN . SENT Kirsty NP Grant NP and CC the DT anonymous JJ reviewers NNS for IN their PP$ helpful JJ comments NNS and CC suggestions NNS of IN improvement NN . SENT This DT work NN was VBD partially RB financed VVN by IN the DT Comision NP Sectorial JJ de NP Investigaci NP n NN Cient NP fica NP CSIC NP , , Universidad NP de FW la FW Rep NP blica NP , , Montevideo NP , , Uruguay NP fellowship NN for IN AM NP and CC equipment NN , , and CC a DT grant NN for IN international JJ cooperation NN from IN the DT French JJ Minist NN re IN des NP Affaires NNS Etrang NP res NNS , , ECOS NP Sud NP U NP 03 CD B NP 01 CD . SENT Competing VVG interests NNS . SENT The DT authors NNS have VHP declared VVN that IN no DT competing JJ interests NNS exist VVP . SENT Author NN contributions NNS . SENT AM NP is VBZ a DT postgraduate NN student NN PEDECIBA NP , , Uruguay NP whose WP$ thesis NN is VBZ being VBG advised VVN by IN AAC NP and CC RB NP . SENT AAC NP and CC RB NP conceived VVD and CC designed VVD the DT experiments NNS , , and CC contributed VVD reagents NNS materials NNS analysis NN tools NNS . SENT AM NP performed VVD the DT experiments NNS . SENT AM NP , , AAC NP , , and CC RB NP analyzed VVD the DT data NNS and CC wrote VVD the DT paper NN . SENT TopSynopsisIntroductionResultsDiscussionMaterials NP and CC MethodsAcknowledgmentsReferences NP ReferencesBastian NP J NP , , editor NN , , 1986 CD Electrolocation NN . SENT In IN . SENT Bullock NP TH NN , , Heiligenberg NP W NP , , editors NNS . SENT Electroreception NN . SENT New NP York NP . SENT Wiley NP Sons NPS . SENT 722 CD p NN . SENT Bell NP CC NP 1989 CD Sensory JJ coding VVG and CC corollary JJ discharge NN effects NNS in IN mormyrid JJ electric JJ fish NN . SENT J NP Exp NN Biol NP 146 CD . SENT 229 CD 253 CD . SENT Find VV this DT article NN onlineBudelli NP R NP , , Caputi NP A NP , , Gomez NP L NP , , Rother NP D NP , , Grant NP K NP 2002 CD The DT electric JJ image NN in IN Gnathonemus NP petersii NP . SENT J NP Physiol NP Paris NP 96 CD . SENT 421 CD 429 CD . SENT Find VV this DT article NN onlineAssad NN C NP 1997 CD Electric NP field NN maps NNS and CC boundary NN element NN simulations NNS of IN electrolocation NN in IN weakly JJ electric JJ fish NN . SENT Pasadena NP California NP . SENT California NP Institute NP of IN Technology NP . SENT Budelli NP R NP , , Caputi NP AA NN 2000 CD The DT electric JJ image NN in IN weakly JJ electric JJ fish NN . SENT Perception NN of IN objects NNS of IN complex JJ impedance NN . SENT J NP Exp NN Biol NP 203 CD . SENT 481 CD 492 CD . SENT Find VV this DT article NN onlineCaputi NP A NP , , Budelli NP R NP 1995 CD The DT electric JJ image NN in IN weakly JJ electric JJ fish NN . SENT I PP . SENT A DT data NNS based VVN model NN of IN waveform NN generation NN in IN Gymnotus NP carapo NP . SENT J NP Comput NP Neurosci NP 2 CD . SENT 131 CD 147 CD . SENT Find VV this DT article NN onlineCaputi NP A NP , , Budelli NP R NP , , Grant NP K NP , , Bell NP C NP 1998 CD The DT electric JJ image NN in IN weakly JJ electric JJ fish NN . SENT II NP . SENT Physical JJ images NNS of IN resistive JJ objects NNS in IN Gnathonemus NP petersii NP . SENT J NP Exp NN Biol NP 201 CD . SENT 2115 CD 2128 CD . SENT Find VV this DT article NN onlineHeiligenberg NN W NP 1973 CD Electrolocation NN of IN objects NNS in IN the DT electric JJ fish NN Eigenmannia NP rhamphichthyidae NP Gymnotoidei NP . SENT J NP Comp NP Physiol NP 87 CD . SENT 137 CD 164 CD . SENT Find VV this DT article NN onlineLissmann NP HW NP 1958 CD On IN the DT function NN and CC evolution NN of IN electric JJ organs NNS in IN fish NN . SENT J NP Exp NN Biol NP 35 CD . SENT 156 CD 191 CD . SENT Find VV this DT article NN onlineRother NN D NP , , Migliaro NP A NP , , Canetti NP R NP , , Gomez NP L NP , , Caputi NP A NP , , et NP al NP . SENT 2003 CD Electric NP images NNS of IN two CD low JJ resistance NN objects NNS in IN weakly JJ electric JJ fish NN . SENT Biosystems NP 71 CD . SENT 169 CD 177 CD . SENT Find VV this DT article NN onlineRasnow NN B NP 1996 CD The NP effects NNS of IN simple JJ objects NNS on IN the DT electric JJ field NN of IN Apteronotus NP leptorhynchus NN . SENT J NP Comp NP Physiol NP A NP 178 CD . SENT 397 CD 411 CD . SENT Find VV this DT article NN onlineAssad NN C NP , , Rasnow NP B NP , , Stoddard NP PK NP 1999 CD Electric NP organ NN discharges NNS and CC electric JJ images NNS during IN electrolocation NN . SENT J NP Exp NN Biol NP 202 CD . SENT 1185 CD 1193 CD . SENT Find VV this DT article NN onlineLissmann NP HW NP , , Machin NP KE NP 1958 CD The NP mechanisms NNS of IN object NN location NN in IN Gymnarchus NP niloticus NN and CC similar JJ fish NN . SENT J NP Exp NN Biol NP 35 CD . SENT 457 CD 486 CD . SENT Find VV this DT article NN onlineCaputi NN AA NN , , Aguilera NP PA NN , , Castello NP ME FW 2003 CD Probability NN and CC amplitude NN of IN novelty NN responses NNS as IN a DT function NN of IN the DT change NN in IN contrast NN of IN the DT reafferent JJ image NN in IN G NP . SENT carapo NN . SENT J NP Exp NN Biol NP 206 CD . SENT 999 CD 1010 CD . SENT Find VV this DT article NN onlineGomez NP L NP , , Budelli NP R NP , , Grant NP K NP , , Caputi NP AA NN 2004 CD Pre NP receptor NN profile NN of IN sensory JJ images NNS and CC primary JJ afferent JJ neuronal JJ representation NN in IN the DT mormyrid JJ electrosensory JJ system NN . SENT J NP Exp NN Biol NP 207 CD . SENT 2443 CD 2453 CD . SENT Find VV this DT article NN onlineCastello NN ME PP , , Aguilera NP PA NN , , Trujillo NP Cenoz NP O NP , , Caputi NP AA NN 2000 CD Electroreception NN in IN Gymnotus NP carapo NP . SENT Pre NP receptor NN processing NN and CC the DT distribution NN of IN electroreceptor NN types NNS . SENT J NP Exp NN Biol NP 203 CD . SENT 3279 CD 3287 CD . SENT Find VV this DT article NN onlinevon NN der NP Emde NP G NP , , Schwarz NP S NP 2002 CD Imaging NP of IN objects NNS through IN active JJ electrolocation NN in IN Gnathonemus NP petersii NP . SENT J NP Physiol NP Paris NP 96 CD . SENT 431 CD 444 CD . SENT Find VV this DT article NN onlineSicardi NP EA NP , , Caputi NP A NP , , Budelli NP R NP 2000 CD Physical JJ basis NN of IN distance NN discrimination NN in IN weakly JJ electric JJ fish NN . SENT Physica NP A NP 283 CD . SENT 86 CD 93 CD . SENT Find VV this DT article NN onlineBregman NN AS IN 2001 CD Auditory JJ scene NN analysis NN . SENT The DT perceptual JJ organization NN of IN sound NN . SENT Cambridge NP Massachusetts NP . SENT MIT NP Press NP . SENT 773 CD p NN . SENT Aguilera NP PA NN , , Castello NP ME PP , , Caputi NP AA NN 2001 CD Electroreception NN in IN Gymnotus NP carapo NP . SENT Differences NNS between IN self NN generated VVN and CC conspecific JJ generated VVN signal NN carriers NNS . SENT J NP Exp NN Biol NP 204 CD . SENT 185 CD 198 CD . SENT Find VV this DT article NN onlineCaputi NN AA NN 2004 CD Contributions NNS of IN electric JJ fish NN to TO the DT understanding NN sensory JJ processing NN by IN reafferent JJ systems NNS . SENT J NP Physiol NP Paris NP 98 CD . SENT 81 CD 97 CD . SENT Find VV this DT article NN onlinePereira NN AC NP , , Centurion NN V NN , , Caputi NP AA NN 2005 CD Contextual JJ effects NNS of IN small JJ environments NNS on IN the DT electric JJ images NNS of IN objects NNS and CC their PP$ brain NN evoked VVD responses NNS in IN weakly JJ electric JJ fish NN . SENT J NP Exp NN Biol NP 208 CD . SENT 961 CD 972 CD . SENT Find VV this DT article NN onlinevon NN der NP Emde NP G NP 1990 CD Discrimination NN of IN objects NNS through IN electrolocation NN in IN the DT weakly JJ electric JJ fish NN , , Gnathonemus NP petersii NP J NP Comp NP Physiol NP A NP 167 CD . SENT 413 CD 421 CD . SENT Find VV this DT article NN onlineQuinet NN P NN 1971 CD Etude NP syst NN matique NN des NP organes NP sensoriels VVZ de FW la FW peau NP des FW Mormyriformes NP Pisces NP , , Mormyriformes NP . SENT Annls NP Mus NNS e NN Royal NP Afrique NP Centrale NP , , Tervuren NP Belgium NP 190 CD . SENT 1 CD 97 CD . SENT Find VV this DT article NN onlineYan NN HY NP , , Curtsinger NP WS NP 2000 CD The DT otic JJ gasbladder NN as IN an DT ancillary JJ auditory JJ structure NN in IN a DT mormyrid JJ fish NN . SENT J NP Comp NP Physiol NP A NP 186 CD . SENT 595 CD 602 CD . SENT Find VV this DT article NN onlineHudspeth NN AJ NP , , Konishi NP M NP 2000 CD Introduction NN Auditory JJ neuroscience NN . SENT Development NP , , transduction NN , , and CC integration NN . SENT Proc NP Natl NP Acad NP Sci NP U NP S NP A NP 97 CD . SENT 11690 CD 11691 CD . SENT Find VV this DT article NN onlineHunter NN P NN , , Pullan NP A NP 2002 CD FEM NP BEM NP notes VVZ Available JJ . SENT http NN . SENT lola NP . SENT unimo NN . SENT it PP fonda NP DISPENSA NP Tb NP html NN Programma NP Prog NP TB NN 4 CD Dipolo NP fembemnotes NNS . SENT pdf NN . SENT Accessed VVN 15 CD June NP 2005 CD . SENT Rother NP D NP 2003 CD Simulaci NP n NN de NP im NP genes NNS el NN ctricas NNS en IN peces NNS el NN ctricos NNS de NP descarga NP d SYM bil NP . SENT Montevideo NP . SENT PEDECIBA NP Universidad NP de FW la FW Rep NP blica NP . SENT 45 CD p NN . SENT TopSynopsisIntroductionResultsDiscussionMaterials NP and CC MethodsAcknowledgmentsReferences NP PLoS NP Computational JJ Biology NN is VBZ an DT open JJ access NN journal NN published VVN by IN the DT nonprofit JJ organization NN Public JJ Library NN of IN Science NN in IN association NN with IN the DT International NP Society NP for IN Computational JJ Biology NN . SENT All DT journal NN content NN , , except IN where WRB otherwise RB noted VVN , , is VBZ licensed VVN under IN the DT Creative JJ Commons NP Attribution NN License NN . SENT