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Unit 5 Eye Witness Memory.docx

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PSYC 3020
Dan Yarmey

Unit 5 Eye Witness Memory Psychological Research and Theory • eyewitness testimony given at trial without any other corroborating evidence can lead to the convition of an accued person in most jurisdictions. • described as, next to an actual confession, the most incriminating evidence that can be introduced against a defendant. • false identifications from lineups and photospreads are responsilbe for more convitions of innocnent persons than al causes combined • January 2008, 210 men found guilt for various criminal crimes were exonerated through the anlysis of DNA typing. Of these 210 cases, 153 (77%) involved from one to up to five eyewitness idenitifcations is the single most common facotr accounting for wrong convitions. • mistaken eyewitness identification int he US account for approvimately 45000 wrongful convitions per year. • constanzo estimated that about a docen people are executed in the US each year for crimes they did not committ, many involving mistaken eyewitness identiifcation. • this suggests that eyewitness evidence presented from well meaning and confident citizens is highl persuaive but, at the same time, is among the least relibale forms of evidence. • witnesses construct and reconstruct memorie based in part on what they selectively percieved at the time of the incidient and partly on their expectations, ebliefs and pre- existing knowledge. • three therotical stages. 1) first there is the observation or acquisition stage in which informaton is percieved and enoded as a memorial representation. 2. is the rention or storage stage. 3. is the retrieval stage in which an individual recalls and/ or recongized stored information. • information cannot be accurately retrieved if it was not perceived, misprecieved information during observations tage will be incorrectly remebered. information can be forgoten, altered or supplemented by factors that occur durin the rentention stage and the retrieval staage • finally, accurate and coplete infoormation may be avalibel in memeory but not accessible because of inapropriate questioning techniques • estimator varaibles are characteristics of the eyewitness or the cirumstances surrounding the observed event because investigators can only estimate their influence on recall and indeitification. • system varaibles are factors which occur during the retnetion and retrieval stages which are under the control of teh police. e.g. the way the quetion is worded. Eyewitness Recall • many lack decrptions lack detail and precision and could apply to many people, accuracy and specificity is important • researchers in laboratory settings have studied using films, videtapes as stimlu, slides, and have investigated person descrptions as a function of staged events, naturalistic field situations and case sutudes and archial anlsysis • these indicate that the fit of a suspect to the orignial decrptio should be accpeted with caution • eyewitness provide equivoccal decption, i.e heihg weight, age often are highly error prone • errors in hair colour, haris tyle, and style and colour of clothing. • overall levels of eyewitness recall usually are comparable for men and women, however, when gender differences do occur they are usually a function of men and womens different interest in genderrelated stimli • descrptionsmay be difficult because witnesses must verball repoduce visually and auditory percieved stimlu of the perpetrator this is hard for a familiar person because vocaultary is limited • police officers have to reconstruct these descrptions in their mind into a visial image that resmbles the orginal person in order to create an artist sketch or wanted poster. • problematic also because witness may not be interviewed until a long period after the incidient EVENT FACTORS, SITUATIONAL FACTORS, WITNESS CHARACTERISTICS, RETENTION INTERVAL Event Factors • greater duration of event, more likely that poeple and actions are observed to notice, observe, interpreted and through about, which promotes reconition and recall • greater frequency, more intense, yeidld more vivid sensory cues(vision, smell, hearing, taste and touch), are more likely to be remembered • movement or motion of objects and poeple also helps to differentiate these stimlu from their background. • better the constrast that an incident has with both preceding and surrounding events the greater the memborable it si situational factors • lighting, vsibility, viewing and listening distance, object speed, background noise, and other factors such as the ptotnetioal for actual violence, the greater or poorer th elikihood of good memory witness characteristics • individual differences among witness like age, stress, heearing, etc. affect the encoding and retrieval of information. • stress of yewtness memeory depends upon the level of physiological arousal experienced by the witness, the source of that stress nd the complexity of the situationor task • moderate stress during ecording stage and recall stage are likely to enhance performance. but high stress imparie performance, particulary if weapons are present whihc may distract attention and encoding • stress acts to distract attention and encoding. leadig to a narrowing of atnetion to salient stimlu and also can promote dicussion and rehersal of the incident • consquenty, sleective attention and discussion can facilitate memeor for accurately encoded inforomation. however, it can also strengthen memory for misinformation acuquired during observation • police officers are no better or no worse than non police as eyewtinesses retention Interval:delay and Intervening Events • remembring depends on factors like the type of and signficance of information to be remmerebd, the tye of memroy test, the level of orignial learning, the strength and similarity or previously acquired information and the ature of the events which occur during the renteion period. • memory for information acquired during a traumtic eet may be superior after short delays than if testing occurs immediately after the stressful experience. • misinformation can be introdced during the storage stage from reading false accounts in newspapers or overhearing conservations of others who may or may not have witnessed the incident. • postevent information effects can influence susquent eyewitness accounts and these effecs have been shown to be very powerful influences acorss a number of studies stimli and situations. • some are suspetible to suggesting they may have observed • interrogation procedures, suggestive questioning, the status of the interviewer, the expsoure of witness to other witnesss descrptions and feedback about their and other eyewitness performance can result in memory distrotiions, changes in certaintiy in correctness of reprots, creation of flase memories • memories can be blended or compromised for person and characteristics as a result of newly acquired information • misinformation effect can influence witnesses congition even before critical event occurs by alertting witnesses expectations that certain information will be encountered. theoretical disagreements to how this occurs. not certain whether new information changes the original memory or creates new meories that block or overlie the original memeory, thus making the oringial memory tempraily inaccessible. EYE witness identification • eye witness idenitificiation has been described as the Achilles heel of the criminal justice system • the purpose of conducting a lineup is to uncover information through reconition memeory that was not avalible in recall memory. the descrption of the prepetrator typically is so general that there is min chance that a suspect actually is the prepetrator or not • mutli person line up assess whether the witness can state that the suspect is the same person the seen and the validity of the witness memory • usually use a computer- generated set of face-and shoulder colored photographs of the suspect and a set of 5 to 11 foils or distracters presentd in an array • phsyical or corporeal lineups are in some jurisdictions- these faces or persons may be presented simultaneously or in squence • they can conduct one persoin lineups or showup confrontations • showups are regarded as highly prejuicial to suspects. they are extremely suggestive because the police may implicitly indicte to the itnes thta they believe that the individual being viewed is th eprepetrator. • if a person views police as authority figure, and trusts them they are going to want to valdiate the prepator • because the identifty of the susepct, regardless of his or her guilt, its obvious, it is difficult to determine whther an indetification is made from memory, or merely by deducing which person is believed by the police to be the suspect • hit scores- accuracy • suspect present line ups with one (35%), two (56%), six (50%), and ten faces (42%). when the suspect was not present in the lineup the false alarm rates were 11, 12, 7, 5. these results suggest that witnesses are less likely to make a false identification of an innocent person as he number of foils are increased. • 6 person lineups were superior to one person lineups in accuracy of identification over a 34 hour rentention period. innocent suspects were at signficantly less risk of being falsely identified in a six-person lineup than in a one person lineup, especially with 2 hour and 24 hour rentetion intervals. • false identitications of innocent suspects were more probable in showup encouters when te suspect was deress in the same clothing as the worn by the prepeator • possible life death situations only, it often usually isnt recommeded that they use showup encoutners • the best and most just identiication procedure is to adminster properly constrcuted and properly conducted many person lineups • two metholdical componenets of lineups. 1. the structural properties (appeacne characterstics of line up members) 2. the proecudural proeprties of lineups (e.g. instructions given to eyewitness prior to viewing) • 1. verbal descriptions of the prepatrator should be obtained from al witnsses prior to conduting a line up • 2.lineups should contain a min of five approprate foils (distractors) for each suspect and each lineup should contain only one susepct • 3. lineups should contain foils who are chosen because they match the witness verbal descpriton of the prepetrator • 4. if the suspect has a distinctive feature w hich was no decribed by the witness but works to mkae this person stand out, all of te foils should have this diistinctive feature • 5. the suspect and foils houd e allowed to differ on non-disctinvie fetaures that were no verbally decibred by the witness. alloing for increase in helpful differences (propitours heterogenitiy) indiscrimination of appearance among lineup members such that the supsect is not procted but reocnition of an innocent foils is not baised • 6. sperate lineups should be conducted for each eyewness in muleip-witness cases. the foils should be changed if possible across lineups. if not possible the position of the suspect and foils shoud be varied acorss witnesses • 7. the lime up adminsitator should not know who the suspect is or whot he foils are. the eyewitness should not be told that the linep admisnitrator does not know whot he susepct is. this reocmmdation is the equivelent of a double blind test in beahvioural experiments • 8. the eyewitness must be told that the perpetrator mght or moght not be present in te lineup. this recommedation is given in order to minimize witness expectation that the perpetrator is present, and that they must select somebody • 9. witnesses should be asked to state whhethe the lineup contains the perpetrtor and if there is an affirmative response to indicate wihch person is teh suspect in question • 10. witnesses should be asked to descirbe in theri own words how confident certain) they are in any idneitication made • 11. al statesments given by the police and by teh witness should be recorded, perferably with videotape, during teh lineup proecudre • 12. where possible, sequiental lineup proceudres should be followed rather than a simluateous presentation of the suspect and foils when compared to sumlutatous lineups, sqeuntial lneup procedures yeild the same nnumber of correct idenitifcations (hits) when the perpetrator is present, but signficantly fewer false identifications when the perpetrator is absent • note- thes accor in earwitness identification of both voices of srangers and voices in familiar persons. --LOOK IN NOTE BOOK.. Repression and Recovered Memory • freud theorized that forgetting of tramatic or distrbuing houghts was a fucntion of repression and that distressing thoughts and feelings were buried in the unconscious. • hot topic again in adults claiming that they have recovered lost memeories of being sexually abused during childhood • most deny chargers of sexual abuse. in their defense, accused parents and others have charged that these recollections are false memories cdreated b overzealous but well intentional therapists through the power of suggestion • researchers question the scienfici baisis of theroies like represision and the use of clincial case studies as evidence • suppports, have accepted the concept of repression as a vaibale mechanism to bury traumatic memoeires of seuall abusive icnidents int heri unconcious- like clincians and therapists. • repression and dissocaition are said to assist traumatized victims in defending against painful awarness of conflictual or catastpic experienced. • supporters- repressed memories of traumatic, once retireved in the presence of approprotate perceptual cues, are more accurate than ordinary, continous memories. • sceptics- robust repression - to denote the dubious status of this mechanism, the completedness of amnesia and the notion that repressed memories remain more intact than other memories are chalenged. • robust repression is a myth they say • the lay model of memory as a video-recorded is constrasted with a scientific reconstructionist model, in which memories are understoof as creative beldning of fact and fiction. • spectics- argue in credible cases of amnesia, the person is usually aware of having a memory gap, an aspect nt often reported in situations of amenesia for childhood abuse. fruthermore, they are assert that there is noscientific data supporting the existence of complete amendia for multiple events (repeated abuse) occuring over an ectended span of time. no sceifnic evidence for workings of repression or dissociation int eh context of recovered memories of rearly abuse.- he concludes there is no laboratory evidence to support the concept of repression. • support-aruge that qualitiatively different mehcanims underlie memories of childhood sexual abuse which clinicans can distinguish in psychotherpay with trumatized clinets which are not discoverable by experimental labortaro investigation.-- ie you cant set up rules for memory in a lba. • sceptics-argue that tramatic experiences are unfrogettable, not repressed like war prisoners. • thus supporters of recovered memory stress the relevance of lincial expertise in the domain of trama; sceptics draw on the rehtoric of scientific rigor and reliability to crtize the thereotical and empircal bases of the recovered memory position • supporters-suggest that childhood sexual abuse is far more widespread than most poeple aknowledge abd believe that the realively few reprots that emerge about adult recovred memoriesof such abuse are true • scpetics-are results of suggestible peple who have real emotional problems, and have been victimzied and persuaded by persauvie therapits or others that their emotional problem must be the reuslt of chilhood seuxal abuse • hyptnsoiss, dream analsis, suggestive questioning, evocative and vicide imagery memory ehancement techniques, suspetible individuals have led to search or and create the memroeis of abuse they assume spontaneously appear from tehir burided conciosus. • trial jduges have rules that the eivdence regarding repression is inadmissble because scienctific experts cannot agree on its realibaility. summary • errors result from factors that influence the norml process of preception, retention, and retrieval of information. • suggestive interview techniques and idenitication procedures can controbue to misidentification. • can improve the accuracy of eyewitness memory by focusin their attention on system varaibles and using identirication procedures validated by empricial research • sceptics have contested the validity of recovered memoreis by questioning the scientific basis of theroeis of repression and the use ofclincial case studies as evidence. • supportsers- have accepted the concept of repression and dissocation as a viable machnism to bury traumatic memories of sexual abuse- the debate continues Readers: Chapter 5: The Psychology of Speaker identification and Earwitness Memory Speaker Identification and Earwitness memory • earwitness identification evidence refers to the process of a witness hearing the voice of a perpetrator and encoding that information in memory, retirving the stored information when called to describe the speakers voice and/ or identify the speaker in a voice lineup and finally, testifying or communicating these repsonses to a police officer, trail judge and or jury. • Speaker recongition is differentiaed from speaker identification: the former refers to general familiarity with one or more voices within a voice sample for whatever reason, whereas speaker identification is the process of discriminating a particular persons voice from a single speech sample or from a number of different voice samples • analysis of speaker identification • Aural-perceptual analysis- involves testing the effectiveness of human listeners in identifying a speaker through auditory procedures, such as a voice lineup • Acoustic procedure- involves machine/ compter analyses.  Forensic acoustic phonetics pertains to computerized/machine anlyses of selcted voice samples for the frequency and intensity of speech sound waves and resonance. • Neither the arual-perceptual apparoch nor the acoustic apparch can uniquely charactierise a persons voice. Speakers cannot be identified with certainity from either audiotry or acoustic procedures • Arural-perceptual speaker identifications are difficult and eror prone • However, some witnesses are signficantly suprior to others in their accuracy of speaker identification for both familiar and unfamiliar speakers. • The probabitly of correct identification of an unfamiliar speaker from a voice lineup who was heard only oncce an for a brief amount of time is about 30%. • Misidentification of unfamilar speakers from target-absent lineups also can be very high  Study- of the wtiness coreectly ejuected the six-voice target absent lineups, respectively. The Courts and Earwitness identification 1. The first scientific experiments on speaker identification were conducted by MCGehee 2. The first record of a court evalutng the probative value of earwitness testmony dates from the 1660 trial in England of William Hulet. Hulet was accused of regicide in the execution of King Charles I. • Critical evidence against Hutlet came from Richard Gittens, who was familiar with Hutlet's voice through membership in the same miliary regiment • Hulet was found guilty of high treason by the jury. Subsquently, the orginal hangman of King Charles I confessed to the exceution and the court being sensible of the injury dont to Hulet, procured his reprieved 3. First documented evidence of ear witness testmony in north amercain poccured in 1861, when a new york tiral judge permitted the testmony of a witness who cliamed that he culd identif the defants dog by hearing its bard as one of the two dogs that had killed his sheep 4. Early in the twentieth century in a case involve the rape of a white women by an unfamiliar balck man whos face was obscured, a flordia judge cncluded that the voice identification based on hearing two sences ws likely accurate 5. Assumption: there is a postivie correlation between the emotional arousal and stess of a victim, and the accuracy of speaker identification. No empriical research is little 6. New york in 1933- following the kidnap and murder of the infant son of colonel Charles lindbergh, the celebrated hero and first man to fly solo across the alantic ocean. Soon after the kidnapping lindbergh talked about negotiated over the telephone with a man claiming to be the kidnapper • Twenty nine months later Germanborn Bruno Richard Hauptmann was accused and convicted of this crime, partly on the basis of Lindbergh's speaker identification • The inherent suggestibility of this one person (show up voice identification and other factos such as cross ethnic idenitfication, length of the rention interval and the size of the voice sample all question the fairness, reliabiltiy and valdiity of this identification • It severed as the first aural erceptual experimens on speaker identificatoin. • Mcghee presented studen research participants with passaes of phrases read by an unfamiliar person staning behind a screen. Subsquently, participants were tested for thier recongition memory of the target and four other speakers.  The effects of delay (randing from 1 day to 5 months); gender difference; ethnicity differences; voice disguise on recongition emmro were investigated.  Difficult to interpet his results From the Court to the Laboratory: Earwitness Memory 7. Commonwealth v. Miles • Victim could not see the particiapnt during procedure, or could they see her. • The defendant selected the order in which he could read • The participants read the same inocuous passage from a fifh-grade reader. Defense counsel attended the procedure and although, consulted never objected to it. In addition, we have viewed a videotape of the voice identification procedure, and conclude that the proecdure was not impermissibly suggestive. The defents voice did not stand out becahe of his age, nor did any othe raspect of the procedure direct undue attention to the defenants voice. Henace, we conclde that the judge properly denied the defendants motion to supress the voice identification 8. United States. v. Duran- • Ninth Circuit affirmed a conviction for bank robbery in which the primary evidence consisted of voice identification at trial by a bank teller. • Both bank tellers were likely very attentive during the roberry given durans weapon and threats, as evidence by their accurate descpritions od druan and his distinctive voice and the fact that neither teller equivoated in ther identification of duran's voice. Moreover , the in-court identifications occured just three months after the bank robbery 9. Assumptions of factors that influence descirptions and identification • Such as the opporunity to observe; • Perptaroyrs quality, loudness, tone of voice during the commission of the crime; • The stress and weapon focus on voce identification • The length of the rention interval • Teh number of suspects in a voice lineup • The selction of foils (fillers) • The use of a live lnup • The nature of the voice script to be uttered by the suspect and the foils in the lineups Differences Between Earwitness Memory and Eyewitness Memory 10.Altough, it has been assumed that estimator varaibles and system variables that influence eyewitness memry funcion in the same manner with earwitness memory, this assumption is not trye 11.Accracy of identification is superior with faces compared to that obtained with voices • Presented photo showups and photo line ups were 57% and 46% respectively • Voice showups and voice lineups were 28% and 9% respectively 12.Witnesses who can both see and hear do not give greater attetion to or have better memory for auditory information as lighting gets poorer. • When a person seens and hears a accused, speech is attented t ofirst of al for meanings, emotions, attudies rather than for identificationpruposes. Moreover, the pesences of auditory information interferes only slight with visual identification of the target 13.In contrast, visial inormation clearly interfers with speaker identification • Speaker identification was signficantly superir in an auditory condition comapred with an audiry visual condition when a voice lineup was used 14.Visual line up was used, facial identifications in a visual consition (75%) were similar and not signficantly different from identifications in n auditory visual condition (64%). 15.Results indicate that visual information can interfere with the processing of auditory infomraiton. A face overshadowing effect also has been demonstraed such athat the voice of an unfamilar speaker is bettter remembered if the targets face was no oseved at the time of encoding 16.Earwitness are vunerable to post event information than are eywitnesses • Experiment where particpants witnessed a videotape automobile accident either visually or aditorily and then were exposed to post event questioning. • Results: although accuracy of speed estimations was greatest in the visual condition, the audiorty condition proved most vulnerable to post eventinfration in both experiments 17.The courts dealing with aural-perceptual idenficiations tend tobe guided by those princples that govern visual identifiation • Theyre not equivlent* • Suspects can easily modify their voices as they speak for a voice lineup, suspectsin a visual standup lineup or photo aray are less able to alter their appearance apart from changes in head hair, facial hari and normal aging. 18.Voice identification eidence is allowed only when the speaker (suspect) is highly familar to the witness or the voice of teha ccused in partciular distinctive- New Sourth Wales Austrialia 19.US and Canada generally allow witnesses who believe that they recongize a voice simply to take the stand and say so. Processing Information for voice identification 20.Problems • Speaker distortion arising from system effects (ppor telephone tramission, background noise, etc) • Person effects (fear, anxiety, health problems, alcohol, intentional disguise etc) 21.Identifications is facilitted by relatiely long speech samples showing an overall conssiteny in pitch,habits and other distinctive characterst in the configuration of sound speech 22.The greater the variety in speech sounds, the better the susquent identification 23.Speaker identification is facilatted when listneres use a pool of voice parameters from which they select subset for auditory reconition, such as pitch level, pitch patterns, and varaibility, vocal intensity patterns, dialect, articulartion, general voice and speech qualitiy and prosody (timing, melody of speech) 24.If one parameter lacks usefulness, reconition and identirifcation can still ocurr if one or more parametres are sufficiently distinctive. 25.Ublike that a sole characteristic determines idenficiation of an individual from all other speakers 26.Because of everday experiences poeple often believe that speaker identification is routine and highly accurate 27.There are inter-speaker varation and between speaker varation. 28.Because of phsysiological differences in the structure of speech mechanisms and use of the voice tract, as well as the infelucne of geographical, educational and socioeconomic factors, different speakers have different sounding voices 29.Within-speaker and intra-speaker varations exist • Speakers do not or rarely pronoucne a given word or phrase in an identiical way on differene occasions even if th second utterance isproduced in succession • Some speakes sound differently from tiem to time because of within speaker changes in intentions, mood states, emotion and stress, thought distractions, situational demands and changes in health and phsyical status 30.Accused may sound differently in spite of the dact that words spoken during the cirme are repated in the lineu. 31.Given these consideraton, the criminal justice suste, must operate on the belief that a witness's voice identification will be based on larger between speaker vartions (foils vs. Suspect) than within speaker artion (suspects voice on different occasions). Characteristics of the witness and suspects in speaker identificaton Indivudal Differences 32.Suggestion has been shown to be capable of evoking false auditory memories 33.Divelopmental Differences in Voice Reconition • Child development studies indicate that voice reconition is present soon after birth. Newborn infants prefer thier mothers voices over unfamilar female voices and can discriminate fmaliar whispered voices from unfamilar whispered voices • Identifications of familiar voices in nursery school children, although inferior to that of adults is signficantly better than chance • Children between the ages of 6 and 9 are equivlemt to the peroframnce of adult listeners in gender classification of adult speakers • Voice identification signficantly improves between the ages of 6 and 10 for recently learned nfamiliar voices, and teh ability of some 10 year olds is equivlent to that of adults • 3 years recongize familar cartoon characters voicces signfcantl better than chance, although they prform signficantly more poorly than 4 and 5 years olds. • All children are more accurate at identifying more fmailiar than they are at identifiying less fmailar voices • Indicate-speaker voice and identity are stored in long term memory at a very young age • Some children with disabilties, such as autism, are ipaired in reconizing and identifying familiar voices and are impaired in voice face matching tasks • Peters found poor performance and no signficant differences in linep identification for target voices. Children and adults have been shown to be equally poor a voice lineup identification • Young children aged 5- to 6 years are highly suggestible in voice identification. Athough instrcuted that the target vice may or may not be present, young children make a high number of false alamrs in target absent lineups • False postives in voice identification decrease with incrasing age of witnesses • That listeners between the ages of 21 and 40 are superior in speaker identification to those over 40. 34.Older adults • Have a deficit in remmebering the source of specific voical infrmation • Confuse words they say and imagiend saying, and words one person said from words another person said • When older adutls lsiten to two speakers and hae to decide later who said what, and are naging in mutlitask processing, theya re less liekyl to differentiate the source of their infrmation • Hearing loss is common with age, esp fir high frequency sunds, it would be expected that voice identification would show a stready decline with increasing age 35.Gender differences • Investigations failed to find gender differences in speaker identification • Found women to be superior to men but only in identitification of female speakers. Similarily, found no signficant differences for men in the reconition of male and demale voices, but owmen were signficantly bettwe at recongizing female than at recongiizing male voices Blind Listeners 36.Studies suggest that the blind are superior to the sighted in sound loccalization, the abiltiy to identify very short intervals between consecutive noise burts and speech discrimination. 37.Similarly, the blind have been shown to be superior to the sighted in identifying speech at low sound levels, particularly in the presences of competeing enviornmental noise 38.However, these superior auditory functins have not been shown to differetially facillate sound recontion or speaker identification 39.Found no signficant differences in sound recongition between congentially blind parcpants (77% accurate and signted individuals (78%) on a test for 184 naturalistic sounds after a 7 day retention period 40.Another study- presented blind and sighted adults with 20 unfamiliar voices and 7 seconds later gave a recognition memory test for the 20 orginal voices mixed with 20 new speakers. No sigficant difference swere found 41.Blind participants were superior to sighted indviduals, but there were no sgifnicant differences within the blnd participants as a function of degree of blindness (e.g.total blind, blind with pereption of light, blind with residual sight, and blind with goodish sight) 42.Experiment testing the accuracy of voice identification by thee groups of particiapnts: voice identifications experts, totalyl blind individuals, and a group of sighted listenres involved in a mock theft. Another experiemnt , participants were told that the target my or may not be presnted in the lineup. • Experts were signficantly better at identification than the other two groups which did not differ signficantly from each other. However, the bblind indicated sgnficantly less condidence than the sighted in the accuracy of thier deicsions. The first experiment concluded that although the blind may be superior to the sighted on some auditory tasks, this does not include an enhanced sensitvity to speaker identificaition. 43.Blind participants may be superior to signted indvidduals in sound vocalization and speech dicrimination but do not appear to b supreior in voice identification lineups in which proepr lineup isntrcutions are given Confidence- Accuracy Correlations 44.Witness condience levels are highly malleable 45.Confidence accuracy correlations in most studies on voice indeificaton for unfamilar speakers are nonsignficant or are realtively low 46.Confidence-accuracy correlations of voice identifications are moderated by conditions present during observation such as voice sample durations, tone and quality of the speakers voice and the fmailiarity of the speakers voice • Found a signficant negative condidnece accuracy relationships with short voice sample surations (18 second). In contrast, no reliable realtionships (with one exceptions) were found for slightly longer durations (36 seconds). For relatively long voice sample durations of 120 seconds and 6 mnutes, signficant postive correlations were found. • Found that voice distincitvenesss yielded signficant negative confidence accuracy correlations. That is, the more confident participants were in the accuracy of their identiffications with speakers who had distrinctive voices, the less correct they were on btoh targe-present and targe absent lineups. In contrast, the confidence- accuracy realtionships for non distinctive voices wer enot signficant on either type of lineup 47.Significant confidence accuracy correlations were found in the target absent lineup for targets who sploke in a normal tone of voice during the comission of a crime were tested with normal tone voice lineups 48.In contrast, no signficant confidence accruacy correlations were found for targets who whispered during the crime and wre tested with a whisper on the voice lineups 49.Shown that the amount of illusimiation avlaible during the comsusion of crime (daylight, twilight, end of twilight, darkeness) has no signficant effect on either accuracy of vocie identification or reported confidence in judgements 50.Another experiment showed that identification for unfamilar voices is typically made with overconfidence; accuracy is often low, and there is little relationship between confidence and accuracy 51.Another finding that earwitnesses were signficantly more confidence in ther accuracy of their lineup identifications whne 1) they knew at the time of enncoding that they would be tested for speaker identification as opposed to not being prepared for an identification test 2) the spoke to the target over the telephone and susquently were given a voice lineup over the telephone, in contrast to witnesses who interacted with the target in field situations 3) they wre given a one-person showup rather than s xi person lineup • One excepton- the confidence-accuracy corrrleations across the different conditions were not signficant 52.Probable- that confidence accuracy relationships are low in most studies or not sificant due to floor effects • Floor effects- accracy of identificatin (hits) for unfamiliar speakers is typically low, and false alarms rates in target absent lineups usually exceed the hit rate across most research studies. Participants howveer, are just as confident in their selections on the target absent lineup as they are in their deicsions on the target present lineup 53.Conclusion- witnesses confidence in their identifcation decision for unfamiliar speakers are not realibale predictors of accuracy of identfication 54.Found signficant coniecne accuracy correations for witnesses who were higly familar (family members, best friends) with speakers normal tone of voice, in contrast to speakers hwo were only moderately famiar (co workers, teammates) or unfamilar (stranger) confidence accuracy correlations as a function of vocie familairt wre no signficant when the speaker shipered his or her utterances Witness Descriptions 55.Themore acurate the orignal desccrption of a suspect, the greater the likeihood of identiication accuracy. 56.Studies show that particpants face to face field situations and in telephone tasmitted speech situatiosn describe only four or five voice characteristics of teh target in spite of being repeastly prompted to remember additional characteristics 57.Most qitnesstes tend to describe specific characteristics, that is, pitch, enunication, and tone of voice, in their free recall 58.Other characterstics such as rate of speech, rate varaition, tremor, expressie style, pasues and nasality are seldom mentioned by witnesses 59.Accuracy of voice identification has not been found to be related to witnesses completeness of descption of voice characteristics or accuracy in recall of what was said by the acccused during the crime, or recall of specific words stated during the crime 60.Accuracy of identification, although sinficantly better than chance, does not differ as a fucntion of the linup containng onyl phrases taken from the crime versus a lineup consisting of nonidentical phrases • Heammersley and reads recommend do not repeat what the accused said 61.Accuracy of identification is sigfnicantly superior, however if the witness particpants in a conversation with the target person, in contrast to simply overhearing the targetsvoice • Found recongition to be three times better for a conversation partner than for an overhearf voice 62.Witness descrptions (ratings) of characterstics of distinctive voices are superior, however, to descrptions of nondistrinctive voices. 63./ratings of characterstics of distinctive voices were found toe be realibel over a 1 week rentin period, ratings of characteristics of nondistrinctive voices were inconsistent over a 24 hour rention interval 64.Found- that ratings made by undergarduate and graduate students of the voices of five police officers who served as foils in a real life lineup in cali were similar to each other on a number of charactersitcs and fiffered signficantly from ratings made of the suspects voice 65.Speech- lanaguge clincials, in contrast to naive listneres, attend to different aspects of voice quality when judging the simialry of voices for oth normal and pathological voices • Suggests when constructing voice lineups, police shold be aware that not all witnesses decptions of vice characterics upon which the linup may be constructed will be as relaible as others • Police must be sensitive to the variablitiy among voice characteristics acorss individuals who may have etiher distinctive or nondistinctive voices and to the varaibiility among police officers who must lsiten to the suspects voice and select matching foils. Verbal Overshadowing Effect 66.Verbal overshadowing effect- it is possible that witnesses decprtions of a perpetartors voice can impare susquent speaker identification accuracy 67.Found- signficantly poorer identification compared with a control condition when lineups were adminsitred soon after witnesses gave verbal descrptions of a targets voice 68.Other studies failed to find a verbal overshawoing effect 69.Differences in the results among these three experiments are probably accounted for by differences in reseach designs employed, such as the types of instructions given to participants, the length of the retention interval between participtns verbal descprtions of the target and teh presentation of the voice lineups, and the types of research participants used. Naive Witnesses versus Phonetic Experts 70.Trained experts in phonetics have bee found to be superior to naive listerns in aural perceptual speaker identification 71.People who have musical talens or professional training in singing have been shown to be superior to their non musical counterparts in tspeaker recognition 72.Not all experts are as accurate in speaker identification as other experts 73.There is no evidence to show that police officers areexperts in voice identification or that their traning makes them superior to naive listenrs 74.Differences in expertness might make these idnividuals more credibale witness than lay poeple Ethnicity and Other- Race and Accented Voices 75.Studies confirmed that white listneres are capable of accurately judging race (white, black) and sex identification from recorded speech samples. 76.Recent research- sshows that speakers ethnicit is judged by american listenrs trhogh nonstndard dialect or racial speech cues. • Very small amoungs of speech are needed to distrinctmate between dialiects of afican american vernacular english, chicano english and standard american english. 77.Reserach in wales shows that most (80%) third generation black immigrants from the west indies are misidentified as whte speakers of the same socioeconomic background. • Factos differ from us on differences other than race, factors could be a function of socioeconomic factors, education, historical and political groupings over time, geographical regions of various sizes ll mat plat a ole in affecting accents, testing procedures as well 78.Listeners (afirican american and white) were asked to identitify speakers with and without foregin accents son after hearing them speak. No signficant differences were found 79.Thompson foun that monolingual english-speaking listenres were sprior to identification of bilingual targets voices after 1week retention interval o spoken englihs, followed by english sploken with a heavy spanish accent, and poorest speaking in spnish. • Replicated- whofound that voice identifiation improved by nearly 200% when the listernes was familar with the langauge, in contrast to when statemnts were spoken in a foregin language. Emotional Arousals/Stress of the Perpetrator and the Victim 80.Accused often exprience stress, anger and anxiety which will be relfected in various speec characteristics such as speaking rate, duration, andnumber of speech outburts 81.Construction of voice linups seldom captures the tone of voice used by perpetrators during commission of crimes 82.If an accused is yelling, accuracy of a lineup identification is signficantly poorer if witnesses are given voice of suspects speaking in normal conversational tones of sppech than if they were tested with loud, angry voices 83.There is no reseach on if the emotional arousal or stress of a victim may or may not interfere with speaker identification Weapon Focus Effect 84.Particpants viewed a videotaped crime showing a man holding a weapon or neutral object while spaking to afemale employee of a bar and grill. Results showed that the presence of the weapon failed to affect the accuracy of voice identification or memory for the targets voice characteristics. • However, participatents in the presence of the weapon were less able to recall the smantic content for difficult to comprehend communications in contrast to less difficult spech materials. Witness Preparation 85.Witnesses preptation has found to signficantly facilatte accuracy of speaker identification. 86.Showed that some voices are so distinctive that they are readily identified without perpreation 87.Found that prepared witnesses in contrst to nonprepared witnesses ked to feel descirbed a target's voice paid paticular attention to the pitch, qualitiy of enunication, and tone of voice. • Consisnte in telephone tranmistted speech and face to face field conditions 88.Witnesses gave few decprtions of voice characteristics and accuracy of identification was low both in lineus and showups • However, prepared witnesses were signficantly more accurate than nonprepared witnesses in their identifications 89.Studies suggest that restoring the contet of the orignal event deos not influnce earwitness identification Speaker Familiarity 90.Studies show near perfect scores for recongition of familiar speakers, 91.Studies indcate that familiarity of speakers is not a guarantee of voice identification • Can occur due to unconcious trasnference, a process that has been democnstrated in eyewitness idenitifcation • Unconcious transference and voice identification, such as the inabilty of a shopkeeper to distingusih between the voice of a fmailiar but innocnet customer and a masked perpetrator heard at the scene of a crime has yet to be empirically investigated. • Witness expectations-poeple tend to expectto hear things they expectt to hear- thus if observers (police) expect to hear a particular person answer a telephone, misidentification of a familiar speaker may occcur if someone else actually answers the call. 92.Study examined the abiliity of experienced phoneticians to identify the voices of highly familiar labortaroy collegagues. • Unfamiliar african american speakers among a larger set of white speakers, 5 out of 10 experts misidentified the speakers as one of teh two familiar afirican american who worked in their laboratory 93.Study- recongition of familiar voices from a close knit network of speakers (unis students who roomed together) shows widely differences acorss speakers • Some familiar speakers are readily identfieid, whereas others are consitenly misidentified, or readily identified. • One listern misidentified his own voice • Speakers with most distinctive regional accents and other idiosyncratic feature were easiest to identify as were speakers with high and low pitch values • Speakers with average pitch values were teh mos difficult to identify 94.Study found an 85% accuracy rate in the identification of highly familiar voices and a 30% false alarm rate for strangers voices after listening to taped 45 seconds voice samples 95.Study-85% accuracy of high familar speakers were correctly identified, wtih a 5% false identification and 10 misses • Moderte familiar speakers 79% were identified with 13% false identifications and 8%misses. • Low familiar speakers 49% were identified, wth 23% false identifications and 28% misses. • Strangers- 55% were correctly rejected, but 45% falsely identified as a familiar person. • Both fmailiar and moderate fmailar voices wer emore readily identifed than low familar and unfamilar voices. • 15% error rate in inddeification may be epxected with a very familar speakers 96.Showed that speakers whispered, only 77% of high familiar speakers were corectly identified (91% were predicted to be accurate), 35% moderate familiar were identified (81% predicted) , 22% low familiar were identified (86% predicted) and 20% unfamiliar voices were correctly rejected (74% predicted). • Apparent that whispered voices do not lead to high identification rates and that potential jurors vastly overestimate the accuracy of identification with both nomral tone and whispered voices • Voice identificatiosn are signficantly overestimated 97.Conclusion- that with normal tones of speech, speaker identification is relatively accurate only with the most fmailiar vocies 98.False identification rates increase as voice familiarty decreases 99.Finding of excedingly high flase identifications (45%) for the oice of starangers, even though participants were premitted to state the did not know. Voice Disguise 100. Whispered voice hides pitch, inflection and intonation, and regardless of their duration are harder to identify 101. Speakers wtih a higher than average pitch tend to increase their pitch levels tend to increase thier ptich levels, whereasthose with a lower than average pitch prefer to disguise thier voice by loewring thier pitch 102. Intoxiation makes it higher voice • Tempos, pasues and hestitations change too 103. Imitation • Study- found that most witnesses asked to identify the voice of a highly familiar politican who was present in a lineup accompanied by the voice of an impersonator correctly selected the politican • However, in a target absent lineup, included the voice of the impersonator but not the voice of the poltican, most particpants mididentifed the impersonators voice as the voice of the politican. Speakers appearance adn voice cues 104. Study- found that etimations made from voice recordings of age, height, and weight signficantly correlated with speakers actual age hieight and weight. The average abslute dfference in age and height and weight estimations were 7.11 yers, 2.94 inches, 25.59 ibs. • Suggests that there are (undeteremined) voice cues that correlate with phsyical characteristics 105. Found sificant corelations between height and weight and actual heigh and weight based on voice recordings, for males 106. Neither male or emale judges acfcurately estaimted deamlespeakers hight or weight and all of teh judgements were underestimations 107. Fiund teh differences btween mens and womens average etimates and actual speaker hgihet and weight were marginal which may elct greater heterogentity among strollers in a city park than in the heights and weights found among undergarudate students 108. Studies assesed listeners abilitiy to give reliable age estimations of unknown speakers by lsitening to thier voices over the telphone. Listernes were asked to identify the sepakers age by choosing one of seven age groups. • Results-listeners were rarely correct ith young speakers and generally overestimated their age • Older speakers ages were underestimated, particulary the 60-66 group who were judged to be 46- 52 • Most accurate estimation was beteen 46-52- year old speakers • Overall correct answers was 27% Stereotypes and Voice Characteristics 109. Listeners given video tapes recordings of different speakers show high consensus of agreement on the speakers personality traits, phsyical appearchance and profession, and these categorizations infleune estmation of speakers characteristics 110. Finding- listeners were superior in voice recongition for stereotypes good guys (medical doctors) in contrast to bad guys( felons) 111. Stereotypes are elecited from judged voicesheard; they can influence regonotion memeory for percieved criinal and non criminal speakers. 112. Powerfulness, atrativeness, and pitch and loudness 113. Study demonstrated in an eyewitnes memory expeiment that when young adults judge the tesitmony of an older eywtiness, the speech of older eyewitness is percieved as notivably weaker than that of young eyewitnesses • Contrast, older eyewitnesse more often prefaced their states ith engativ equalifers 114. High credibiltiy in both young adults and older adults wre associated with utterances contiang very few negative equalifiers Situational Factors Affecting Earwitness Memory 115. Voice sample durations • The longer the opporntiy to listen to a speaker, the greater the accuracy of identification • And false alarm rates- because of the inconsistent false alarm rates acorss these four experiments, conclusions about mistaken identification as a function of voice sample duration are not warranted at the present time 116. Disributed exposures of speech samples • Three seperate exposures of one min each than one mass esporesu of 2 mins in total dration. • Study distrbuted exposures signficantly increased voice identification realtive to the massed presentation • Replicated findings- but found that only wo distributed voice samples rather than three distribted samples werie sginficantl better than a massed trial • Found that two but not three distrpued exposures signficantly improved identification performance relative to one massed trial 117. Duration estimations • Knwoledge of events durations usually is based on witness estimations, and estimated durtion of speech events has been error prone. • Study- speech lasting between 15 seconds adn 8 mins. Is signficantly overestimated with women giving substanially greater overestimations than men 118. Rentention intervals 119. Memory of unfamilar voices tend to decline over time • Little loss is found in 24 hour period • Study- that correct identifications didnt differ for voices test over a wweek period but false alarms signficantly increased over this period, esp for an accued voices intially heard with short exposure durations • Study- naural convo, rentetion intervals of between 2 and 14 days isnt ffected • Performance depends (3 week period are difficult to predict) as they depend on attention, differences in voice distinctiveness, ease of acquisiton, the lengh of the orginal voice sample, changes in voice quality between the orginal observation and test Multiple Perpetrators 120. Finding- that recngition performance showed signficant improve as the number of voices to be learned decreased from 20 t 5 Telephone transmitted speech 121. Nosiy backgrounds, degration of the speech single, distortions in tramission, 122. Study-demonstrated that identification of a traget voice heard orginally from a tape recorded and tested with a tape recorded is signficantly betwetn than identification of voices involved wtih tepehone tramissions because the context keeps voice quality consisten 123. Also indicate that if a voice is heard over teh phone adn tested over the phone, acucracy performance is equilvent to tht in which participants orginally heard the voice over the telephone and then wee tested directly with a tape recorded linup. • Police woldnt have to replicate the phone-pphone condition to fin relaible results 124. Study - although speaker identification was signficantly better than chance, no signficant differences were found on target present and target sbent showups or six person lineups for telephone tspeech and testing conduted in suit 125. Finding-that the only difference betwen face to face spsech and phone spech is greater freqec in phone speech of filled pasues to signal their intent to continue to speak which in face to face communcatio is communicated by faicial expressions or gestures. 126. Study- phone to tape recorded showed no differences in accuracy of identification, althouh less confident was associated with phoen voices. 127. Suggests that phone reocordigs of voice lineups could be used for speaker identification without loss i acurracy of identification 128. Finding- that witnesses wer emor than wtice as likely to falsely identify the most similar sounding foil in a target absent showup condition than they were in a six person target absent linup in both telephone tramistted speech and face to face situations. Investigative:procedures 129. Voice lineups are in control of the police Investigative interviews and earwtiness memory 130. Statement analysis, hypnosis, the congtive interview, strcuture interview 131. Strcuture interview, empahise social psychological component such as rapport bulidng, and interviewer social skills, offerns another effective interview technique for eyewiness recall 132. Study- between cognitive interview and strcuture interview failed to show that earwitness decprtions and earwitness identifications are diferentially facilated by these two interview strategies. Lineup construction 133. Study- a suspects voice wll appear salient if his voice sample is based on recordings of spontaneous speech and all of the foils are recorded reading these same words or phrases • Spontaneous speech is obtained by srrpetitious recording of the suspects voice and is typically edicated and rerecrded by police for the voice lineup. • Problems: spliciing of voice can conclude theres two voices due to differs in pitch • Read speech differs from spoanteous speech in terms of pitch, speech rate, speaking tempo, pasues and hesitations.  Differs in speech styles can lead to distortions  Recommeded they read speech for 60 seconds to proide good stuff;; and sponteous one could be given as well  Six speakers are best  Stdies- phrases or words used by the offender have not yelied higher accuracy of identifications (hits) or lwoer flase identifications of innocent suspects than lineups ocntaining non identicial phrases Lineup identifications: remmeber or just know retreival strageties • Results showed a remmebered voice was moe likely to be corrct than a just know voice. • Rememberd voices were more accurately identfied than just know voices when witnesses were given massed trial as opposed to two or three distributed exposure to the targets voice during the acuqistion stage • Remembered unfamilar speakers are probably recongized more correctly because processing inolves feature analysis to a greater extent than pattern recongition • Pattern reonction is more liekly t be the perfered processing stragey for intideiticaion of familiar speakers Single- Person (Showups) versus Many-Person Lineups 134. Study- accuracy of identification in showups and in sex personal lineups was poor 135. Study- that signficantly more false identifications of the innocent suspect were found in the showup than in the lineup condition. Earwitness identification: guidelines and reommednations 136. Read them in course reader Repressed, Dissocation and Recovered Memory Debate: Constructing Scientific  Evidence and Expertise Discourse, Rhetoric, and Rationality • Unlike the realist view that language transparently reflects the world, the discursive approach stresses the power of discourse to construct reality • Knowledge and reality are thus viewed as “cultural categories, elements of discourse, invented, used and defended within social practices” Repression, dissociation, and recovered memory are examples of such cultural categories. • Within empiri- cist accounts, scientists depicted facts as speaking for themselves: • A scientist’s own activities were thus treated as empirically grounded and disinterested. In contrast, scientists often used the “contingent repertoire” to account for other scientists’ errors with reference to personal factors such as their ambition, narrow- mindedness, and social ties • The mention of extra- scientific factors, such as the biases of one’s opponent, undermines the truth status of his or her claims. The rhetoric of science is similarly used in arguments about the facticity of repression, dissociation, and recovered memory. REPRESSION AND DISSOCIATION: CONSTRUCTING/DENYING THEORY AND EVIDENCE Sources and Method • Keyword searches (“repression” and “dissociation”) identified sources in databases of psychological abstracts • , we restricted the time span of publication from 1990 to 1996 • Monographs, coauthored volumes, and chapters from edited books, written for scientist- practitioners, lay persons (or both) were chosen because the legal context involves the interplay between scientific and lay understandings of repres- sion, dissociation, and memory. • american sources were selected for several reasons. In the legal context, ideas in the behavioural sciences may diffuse from the U.S. to other jurisdic- tions • Furthermore, Americans have figured prominently in the development of the recovered memory contro- versy • Finally, in the American sources, writers cited each other’s work explicitly. Defining Repression and Dissociation: Positions of Proponents • upporters or proponents of recovered memory typically describe themselves as clinicians w
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