The discrimination of auditory temporal patterns : effect of temporal position, channel, and intertone time statistics

136 Pages·1996·4.3 MB·English

by  Sadralodabai, Toktam, 1963-

THEDISCRIMINATIONOFAUDITORYTEMPORALPATTERNS:EFFECTOF
TEMPORALPOSITION,CHANNEL,ANDINTERTONETIMESTATISTICS
By
TOKTAMSADRALODABAI
ADISSERTATIONPRESENTEDTOTHEGRADUATESCHOOL
OFTHEUNIVERSITYOFFLORIDAINPARTIALFULFILLMENT
OFTHEREQUIREMENTSFORTHEDEGREEOF
DOCTOROFPHILOSOPHY
UNIVERSITYOFFLORIDA
1996
ACKNOWLEDGMENTS
Iwouldliketothankmyfamily,especiallymymotherandmysister,fromthebottom
ofmyheartfortheircontinuoussupportandencouragement:mymother,forbeingagreat
rolemodelthroughoutmylifeaswellasprovidingmewithhercontinuoussupportinevery
possibleway;mysister,whoseloveandsupporteverystepofthewaygavemethestrength
andencouragementtokeepgoing.
Very special thanks also go to my friends, who put up with me when I was
unbearable. Iespeciallywouldliketoacknowledgeandthankmydearfriend,Dr.Kourosh
Saberiforhisfriendshipandendlesssupportaswellashisvaluabletimeandassistance
wheneverIaskedfororneededit. Itrulyappreciateit. IthankDr.DeeMontgomery;her
friendshipandwillingnesstoalwayslistenandofferhelphasmeanttheworldtome. Ialso
thankChrisHays,mybuddy,whosejokes,pranksandfriendshipkeptmegroundedduring
thetimewhenItrulyneededit,andJoshFryman,whohasbeenatruefriendandwillalways
beinthatcategory. IthankJenniferNye;herfriendshipduringthepastyearhasbeena
breathoffreshair. Lastbutnotleast,IwouldliketothankSeanCollins,whoseloveand
companionshiphasbeenasourceofsupportandcomfortduringthemosttryingmoments.
Myspecialthanksgotomyadvisor,Dr.RobertSorkin,forhiscontinuousguidance
andpatiencewithmydissertation, Idoappreciateallhiscontributions. Finally,Iwouldlike
togratefullyacknowledgemycommitteemembers,Dr.JeffFarrar,Dr.DavidGreen,Dr.
JohnMiddlebrooks, andDr.DavidPerrottfortheirvaluabletimewithmystudy.
This researchwas supported bygrantsfromtheAirForceOffice ofScientific
Research.
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TABLEOFCONTENTS
page
ACKNOWLEDGMENTS
jj
LISTOFFIGURES
ABSTRACT ix
INTRODUCTION
1
PatternRecognition 2
CodingofInformationinthePatternofAuditoryStimuli 4
RelatedPhysiologicalReports 11
CurrentExperiments 12
THEMODELFORWEIGHTESTIMATION 14
DENSITYFUNCTIONSFORTEMPORALPATTERNDISCRIMINATION 20
EXPERIMENTI 29
Method 29
Results 35
EXPERIMENTII 45
Method 46
Results 50
EXPERIMENTIII 88
Method 88
Results 91
GENERALDISCUSSION 95
iii
BinauralPatternDiscriminationandSomeImplications 98
IdealDistributionofWeightsinaPatternDiscriminationTask 104
EfficiencyofWeightDistributions 108
GuidelinesforFutureExperiments 114
REFERENCES 119
BIOGRAPHICALSKETCH 124
IV
LISTOFFIGURES
Figure
page
1. Varianceoftheabsolutedifferencedistribution[VAR(g)]isplottedasafunction
ofthevaluesofthestandarddeviationoftheintertonetimes 24
2. Themeanoftheabsolutedifferencedistribution[E(g)]isplottedasafunctionof
thevaluesofthestandarddeviationoftheintertonetimes 25
3. td'imiessp.loTttheedasstaarfsuynmcbtoilosnroefptrheesevnatlutehseoprfetdhiectsitoannsdafrrdomdeRviOaCtioannaolfystihse.iTntheertsoonleid
linerepresentsapower-functionfittopredictions(Eq.20) 28
4. ThetoppartofthisfigurerepresentsasampleofSAMEtrialsforthetwo
sequencesofapattern,whereasthebottomportionrepresentsasampleof
DIFFERENTtrials. Thefrequencyanddurationofeachtonewas1000Hzand
25msrespectively 33
5. Inthisfigure,eachsequenceisdividedinto2 subsequences,AandB. A50ms
gapseparatesthetwosubsequences. Thetoppartofthefigurerepresentsa
sampleofSAMEtrialsforthetwosequenceofapattern. Thebottompart
representsasampleofDIFFERENTtrials 34
6. Relativeweightsareplottedasafunctionofeachtemporalposition. The
sequencecorrelationisequalto0. Eachpanelrepresentsdataobtainedfromone
listener 36
71.0. Relativeweights,averagedform4listeners,areplottedasafunctionofeach
temporalposition. Thesequencecorrelationisequalto0. Theerrorbars
representonestandarderrorofthemean 37
8. Relativeweightsareplottedasafunctionofeachtemporalposition. The
sequencecorrelationisequalto0.8. Eachpanelrepresentsdataobtainedfrom
onelistener 38
9. Relativeweights,averagedform4listeners,areplottedasafunctionofeach
temporalposition. Thesequencecorrelationisequalto0.8.Theerrorbars
representonestandarderrorofthemean 39
Relativeweightsareplottedasafunctionofeachtemporalposition. Both,the
sequencecorrelationandtherepetitioncorrelationareequalto0. Eachpanel
v
representsdataobtainedfromonelistener 41
11. Relativeweights,averagedform4listeners,areplottedasafunctionofeach
temporalposition. Both,thesequencecorrelationandtherepetitioncorrelation
areequalto0. Theerrorbarsrepresentonestandarderrorofthemean 42
12. TheupperpartofthisfigurerepresentsasampleoftheSAMEtrials,whilethe
lowerpartrepresentstheDIFFERENTtrialsforthecontrolconditionof
Experiment2 48
13. Thisfigurerepresentsasummaryofthestimuliusedinthefirstcaseof
Experiment2. Inthiscase,thesecondorthesixthintertonetimehasadifferent
meandurationthanallothers. Thestandarddeviationisthesameforall
positions 49
14. Thisfigurerepresentsasummaryofthestimuliusedinthesecondcaseof
Experiment2. Inthiscase,thesecondorthesixthintertonetimehasadifferent
standarddeviationthanallothers. Themeandurationisthesameforall
positions 51
15. ControlconditionforexperimentI. Relativeweightsareplottedasafunctionof
eachtemporalposition. Eachpanelrepresentstheobtaineddataforeach
respectivelistener. Themeanandstandarddeviation,foreachposition,were60
and20msrespectively 52
16. Theaveragerelativeweights,from4listeners,areplottedasafunctionofeach
temporalposition. Theerrorbarsrepresentonestandarderrorofthemean. The
meanandstandarddeviation,foreachposition,were60and20msrespectively.53
17. Relativeweightsareplottedasafunctionofeachtemporalposition. Eachpanel
representsdatafromonelistener. Themeandurationforthesecondpositionwas
20,40,80,100ms 54
18. Theaveragerelativeweights,fromalllisteners,areplottedasafunctionofeach
temporalposition. Theerrorbarsrepresentonestandarderrorofthemean. The
meandurationforthesecondpositionwas20,40,80,100ms 58
19. Relativeweightsareplottedasafunctionofeachtemporalposition. Eachpanel
representsdatafromonelistener. Themeandurationforthesixthpositionwas
20,40,80,100ms 63
20. Theaveragerelativeweights,fromalllisteners,areplottedasafunctionofeach
temporalposition. Theerrorbarsrepresentonestandarderrorofthemean. The
meandurationforthesixthpositionwas20,40,80,100ms 67
vi
21. Thisfiguredepictsaveragerelativeweightsasafunctionofthedifferentmean
valuesforthesecondtemporalposition 71
22. Thisfiguredepictsaveragerelativeweightsasafunctionofthedifferentmean
valuesforthesixthtemporalposition 72
23. Relativeweightsareplottedasafunctionofeachtemporalposition. Eachpanel
representsthedatafromonelistener. Thestandarddeviationforthesecond
positionwas40,60,100ms 74
24. Theaveragerelativeweights,fromalllisteners,areplottedasafunctionofeach
temporalposition. Theerrorbarsrepresentonestandarderrorofthemean. The
standarddeviationforthesecondpositionwas40,60,100ms 77
25. Relativeweightsareplottedasafunctionofeachtemporalposition. Eachpanel
representsthedatafromonelistener. Thestandarddeviationforthesixth
positionwas40,60,100ms 80
26. Theaveragerelativeweights,fromalllisteners,areplottedasafunctionofeach
temporalposition. Theerrorbarsrepresentonestandarderrorofthemean. The
standarddeviationforthesixthpositionwas40,60,100ms 83
27. Thisfiguredepictsaveragerelativeweightsasafunctionofthedifferentstandard
deviationvaluesforthesecondtemporalposition 86
28. Thisfiguredepictsaveragerelativeweightsasafunctionofthedifferentstandard
deviationvaluesforthesixthtemporalposition 87
29. ThetopportionrepresentsasampleofSAMEtrialsforthetwosequencesofa
patternintherandom-modebinauralcondition. Thebottomportionrepresentsa
sampleofDIFFERENTtrialsinthiscondition. Thefrequencyanddurationof
eachtonewas1000Hzand25msrespectively 90
30. Theabscissarepresentstheexperimentalconditionsandtheordinaterepresents
thepercentcorrect. Eachpanelrepresentsthedatafromonelistener 92
31. Averagepercentcorrectisplottedasafunctionoftheexperimentalconditions.
Theerrorbarsrepresentonestandarderrorofthemean 93
32. Averagepercentcorrect,for4listeners,isplottedasafunctionofthe
experimentalconditions. Thesolidlinerepresentstheobtaineddata,andthe
dashedlinerepresentsthemodel'sprediction 100
33. Thedataconnectedbythesolidlinerepresenttheaveragerelativeweights,from
Vll
alllisteners,asafunctionofeachtemporalposition. Thedashedlinerepresents
theidealweights. Thestandarddeviationforthesixth positionwas40,60,100
ms 109
34. EfficiencycalculationsfromExperimentI. Theordinaterepresentstheefficiency
valueandtheabscissarepresentsthecorrelation 113
35. Efficiencycalculationsfrompart1ofExperimentII. Theordinaterepresentsthe
efficiencyasafunctionofthevalueofthemeanintertonetimeforthesecond
position 115
36. Efficiencycalculationsfrompart1ofExperimentII. Theordinaterepresentsthe
efficiencyasafunctionofthevalueofthemeanintertonetimeforthesixth
position 116
vm
AbstractofDissertationPresentedtotheGraduateSchooloftheUniversityofFloridain
PartialFulfillmentoftheRequirementsfortheDegreeofDoctorofPhilosophy
TfffiDISCRIMINATIONOFAUDITORYTEMPORALPATTERNS:EFFECTOF
TEMPORALPOSITION,CHANNEL,ANDINTERTONETIMESTATISTICS
By
ToktamSadralodabai
May1996
Chairman: RobertD.Sorlcin
MajorDepartment: Psychology
Forallthreeexperiments,listenerswerepresentedwith2sequencesof9tones. The
tonedurationswerealways25msandthesequencepatternsweredefinedbyintertonetimes.
Thelistenerhadtodecideifthetwosequenceswerethesameordifferent. Threestudies
examinedtheimportanceoftemporalposition,meanandvarianceofintertonetimesandthe
effectofauditorychannelonlisteners'decisionsinanauditorypattern-discriminationtask.
Thefirststudyexamined,usingacorrelation-weight-estimationtechnique,theability
oflistenerstoallocatedecisionweightstoeachintertonetimeoftheauditorytemporal
pattern. Thisstudyinvestigatedtheimportanceofordinalpositionwithinthesequenceon
listeners'decisions. Resultsshowedthatalllistenersconsistentlyallocateddifferentweights
todifferenttemporalpositions,withthefirstpositioncarryingthelargestweight. Theeffect
IX
ofrepetitionofsomeofthecomponentsinthesequence(rhythmicity)ondiscriminationof
thetemporalpatternswasalsotested. Resultsshowedthatthisalterationdidnothavea
noticeableeffectonperformance.
Thesecondstudyexaminedtheabilityoflistenerstoallocateweightstotemporal
positionsbasedonthediagnosticityoftheinformationprovidedbyeachcomponent’s
position. Bydiagnosticity, itismeanteitherthe magnitudeofthat informationorits
statistical difference from the other intertone times. Results indicated that assigning
differentstandard-deviationvaluesaffectedthelisteners'weight-distributionstrategygreatly,
whereasassigningdifferentmeanvaluesdidnothaveanoticeableinfluence.
The third study examined the effect ofsequence presentation across auditory
channels. Inonecondition,theeartowhicheachtoneofthesequencewaspresentedwas
chosenrandomly,andinasecondcondition,thetoneswerepresentedinalternatingorder
betweenthetwoears. Theresultsdemonstratedthatwhenthetonesofasequencewere
presentedrandomlytoeachchannel,performancewasatchance(0.5probabilityofcorrect
responseina2IFCtask). However,whenthetoneswerepresentedalternatelyandlisteners
wereexpectingthestimulatedchannel,theirperformancegreatlyimproved(approximately
0.75-0.80probabilityofcorrectresponse).
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