Earwitnesses: effects of accent,retention and telephone

An experiment was conducted to investigate the effects of accent, telephone and a relatively long retention interval (3 or 8 weeks) on speaker identification. Three‐hundred and sixty participants heard the target's voice and were asked to identify the target by means of a line‐up consisting of 6 voices. Half of the participants were given a target‐present line‐up and the other half a target‐absent line‐up. The results showed that 24% of participants correctly identified the target in the target‐present condition (hits), whereas 50% of participants incorrectly identified a person as the target in the target‐absent condition (false alarms). The speaker with the standard‐accented voice was more often correctly recognized than the speaker with the non‐standard‐accented voice. No difference was found between identification accuracy after one, three or eight weeks and between the telephone and non‐telephone conditions. It can be concluded that there is a relatively high probability that an innocent defendant is identified as the perpetrator, even in a procedurally correct voice line‐up (in this experiment 8%). Furthermore, reliability may be drastically reduced when the perpetrator has a strong accent, unfamiliar to the listener. On the other hand, reliability of a voice line‐up seems not to be affected by a presentation over the telephone, as well as by a retention interval of at least 8 weeks. Copyright © 2006 John Wiley & Sons, Ltd.     

Earwitness identification performance: the effect of language,target, deliberate strategies and indirect measures

The present study examined whether voice identification performance is influenced by language comprehension (i.e. familiar vs. non‐familiar language) and target presence (target‐present (TP) vs. target‐absent line‐ups (TA)). It also looked at the relationship of deliberate strategies and indirect measures (i.e. confidence, difficulty and pressure) with performance. Sixty Native English speakers were exposed to an auditory event involving 45 to 50 seconds of speech. After 30 minutes delay, participants listened to a voice line‐up (TP or TA) in either a familiar (i.e. English) or unfamiliar language (i.e. French) according to the language spoken during the event, and were then asked to identify the original speaker's voice. Participants demonstrated significantly better performance for the familiar language/TP line‐ups. Participants who reported using the ‘elimination’ strategy were significantly more accurate than participants who reported using either a ‘matching’ strategy or no strategy. Indirect measures were not found to be good predictors of performance, except for confidence regarding TA accuracy. Copyright © 2006 John Wiley & Sons, Ltd.     

Exposure duration: Effects on eyewitness accuracy and confidence

The current study examined the relationship between the length of exposure to a face in an eyewitness setting and identification accuracy and confidence. A sample of 164 young (ages 17–25) and older (ages 59–81) adults viewed a simulated crime in which they saw the culprit's face for a short (12 s) or long (45 s) duration. They were then tested with a target absent (a line‐up not containing the culprit) or target present line‐up. Identification accuracy rates for both young and older participants were significantly higher under the long exposure condition. In the short exposure condition, witnesses who had made a correct identification of the target were more confident than incorrect witnesses. In the long exposure condition the confidence ratings of accurate and inaccurate witnesses did not differ. Discussion focuses on the extent to which extended exposure may inflate confidence judgments and variables that may moderate the relationship between exposure duration and face recognition accuracy.     

A language effect in voice identification

Bilingual students recorded messages in English, Spanish, and English with a strong Spanish accent. Monolingual English-speaking subjects heard a single message and attempted to identify the voice in a six-person line-up 1 week later. The line-up message was delivered in the same language and accent as the initial message. Voices were identified best when speaking English and worst when speaking Spanish. Identification accuracy was intermediate for the accent condition. There were no reliable differences among conditions in false alarms when the target voice was absent from the line-up. The effect of language was replicated using a 30-min retention interval. Familiarity with the language and language constraints on voice characteristics were discussed as possible explanations of the language effect.     

Voice identification of an abductor

A total of 288 male and 288 female undergraduate students heard a taped voice of a mock abductor for a total of 18 seconds, 36 seconds, 120 seconds, or 6 minutes. One-third of all subjects heard the voice for one massed trial, one-third for two equal periods separated by a 5-minute inter-trial interval, and the remainder for three equal periods separated by 5-minute intervals. Voice identification and confidence of response were tested immediately after observation, or 24 hours later, or 1 week later. Hit rates were significantly greater with longer voice-sample durations, and were superior with two distributed exposures to the suspect's voice in contrast to one massed exposure or three distributed exposures. However, the false alarm rate in the suspect-present line-up differed significantly as a function of voice- sample durations and retention intervals, and voice-sample durations and frequency of distributed exposures. False alarms in the suspect-absent line-up were consistently high (overall M = .58) and exceeded the overall hit rate (M = .40). Confidence of response was negatively correlated with suspect identification in the 18-second voice-sample condition, but was positively correlated with voice-sample durations of 120 seconds and 6 minutes.     

Two field studies on the effects of alcohol on eyewitness identification,confidence, and decision times

In two field studies, bar tenants (Ns = 86 and 190, respectively) were successively approached by confederates C1 and C2 on a night out. Confederate C3 then presented participants with a six‐person target‐absent or target‐present lineup concerning C1 or C2 (immediate test). Several days later, participants viewed a lineup regarding the confederate they had not attempted to identify earlier (C1/C2; delayed test). An immediate compared with a delayed, sober identification test did not increase the risk of a false identification decision. A blood alcohol concentration of 0.06–0.07% best discriminated accurate from inaccurate decisions. Choosers with a blood alcohol concentration ≤ 0.06% showed excellent calibration and little overconfidence, and their confidence was a strong indicator of accuracy (i.e., good resolution). Choosers with a higher intoxication level displayed poor calibration and strong overconfidence. Nonchoosers were generally poorly calibrated. Combined analyses showed a negative effect of intoxication on one's ability to discriminate the target from nontargets.     

The effects of post ‐identification feedback and age on retrospective eyewitness memory

Two studies examined the effects of post‐identification feedback, age, and retention interval on participants' memories and beliefs about memories for a videotaped event, as captured by a store surveillance camera. After viewing the video, they were then asked to identify the suspect from a target‐absent photo line‐up. After making their identification, some participants were given information suggesting that their identification was correct, while others were given no information about the accuracy of their identification. In both experiments participants who received confirming feedback indicated they were more confident in their identification, paid more attention to the video, and that they were more willing to testify in court than those who received no feedback. The confidence inflation effects of post‐identification feedback did not vary with retention interval or age. These results are consistent with a position focusing on accessibility, which suggests that witnesses have little or no retrievable recollection of how sure they were at the time of their identification. Copyright © 2005 John Wiley & Sons, Ltd.     

Recall accuracy and illusory memories: when more is less

In two experiments it was revealed that manipulations that increased recall of studied list items also increased false recall of theme-related, critical nonpresented words. In Experiment 1 subjects listened to a series of short word lists, each containing items associatively related to a theme, while engaging in either semantic or nonsemantic processing. On an immediate free recall test semantic processors demonstrated greater correct recall as well as more illusory memories of critical nonpresented items than nonsemantic processors. In Experiment 2, the short study lists were combined to form longer lists that were presented either blocked by theme or in a random presentation order. Retention interval was also varied as participants were tested either immediately, one week after, or three weeks after the study phase. Presenting the target items in a blocked, as opposed to random, format increased recall accuracy, but this was at the expense of a higher intrusion rate for theme-consistent items. Interestingly, the level of false memories was not affected by retention interval even though typical decrements in the recall of study items were observed over time. The results of these experiments highlight the persistence of the false memory effect, as well as pointing to several factors, primarily semantic processing, that may lead to the creation of false memories. Interpretations are offered within the theoretical frameworks of source monitoring and fuzzy trace theory.     

Voice Identification Over the Telephone1

Following a telephone survey investigating attitudes toward police and frequency of personal victimization. 177 citizens between the ages of 18 and 88 years participated without forewarning in a field study on telephone voice identification. Identification accuracy (hits) improved with longer conversation durations (an average duration of 7.8 min compared to conversation durations of 3.2 min and 4.3 min. on average), but the false alarm rate also reliably increased with longer durations in a target-present lineup. False alarms were consistently high (overall M= .48) in the target-absent lineup. No significant differences were found in hit scores or false alarm scores over a two to three day retention interval. No significant correlation was found between confidence scores and accuracy of performance on the target-present lineup (r= .10). but a significant correlation (r= 36) was found on the target-absent lineup.     

‘Earwitness’ voice recognition: Factors affecting accuracy and impact on jurors

Two studies were conducted examining voice recognition testimony and its impact on jurors. In the first experiment, subjects listened to a tape recording of a brief sales pitch. After a retention interval of either 0, 7 or 14 days, subjects were unexpectedly asked to pick the salesperson's voice out of a five-voice taped lineup. Retention interval did not have a significant effect on hit rates or false alarms. Accuracy and pre-lineup confidence were not significantly correlated, although accuracy was related to post-lineup willingness to testify. In the second experiment, undergraduate subjects were asked to read a summary of a trial, describing a situation similar to that studied in experiment 1; the independent variables were the presence of an earwitness, the gender and confidence of the earwitness, and the retention interval. Only the presence of an earwitness had a significant main effect upon mock jurors' verdicts. However, there was a significant interaction between witness confidence and witness gender when an earwitness identification was presented.     

The effect of post‐identification feedback on the recall of crime and perpetrator details

The present study examines the effect of identification feedback on the quantity and accuracy of crime event details recalled, willingness to attempt misleading questions and confidence in the accuracy of these details. All participants (N = 60) viewed a short video clip of a staged building society robbery and then made a false identification of the robber from a target‐absent photospread. Eyewitnesses were next given confirming feedback (i.e. told that they had identified the suspect), disconfirming feedback (i.e. told that they had failed to identify the suspect) or no feedback. All eyewitnesses then attempted a series of short‐answer questions relating to details about the robber, accomplice, victim, building society, theft and getaway. Disconfirming feedback significantly reduced eyewitness confidence in recall accuracy but there was no significant effect of feedback on the overall quantity and accuracy of details recalled or willingness to attempt misleading questions. The theoretical implications of these results are discussed. Copyright © 2005 John Wiley & Sons, Ltd.     

Environmental context-dependent eyewitness recognition

The present study helped resolve the apparent conflict between many laboratory list-learning studies, which have not found environmental context-dependent recognition memory, and staged field studies (e.g. Malpass and Devine, 1981), whose results with ‘guided memory’ techniques suggest that eyewitness face recognition should depend upon environmental context reinstatement. It was found in two different experiments that, relative to testing in a new place, returning participants to the environment where a live staged event had occurred improved performance on identification of a confederate's face (i.e., hit rate). Although physical reinstatement improved identification performance in Experiment 1, mental reinstatement instructions to subjects tested in a new environment did not improve identification performance over an uninstructed group. The environmental reinstatement effect did not interact with test delay or confederate. In Experiment 2 it was found that environmental reinstatement improved accuracy (hit rate and foil identification rate) when the correct target was present in the test line-up, and that false identifications were not significantly affected by contextual manipulations when the correct target was absent from the line-up. The results provide an empirical basis for the hypothesis that returning to the scene of an event improves eyewitness face recognition.     

Typicality effects on memory for voice: Implications for earwitness testimony

The effects of voice typicality on voice recognition were examined. In an incidental task, participants were presented with consonant‐vowel‐consonant stimuli (with varying vowels) spoken by voices rated as high‐typical or low‐typical. One week later, they were brought back for a surprise voice recognition test where the target voice was presented along with low‐typical and high‐typical voice distracters. The results indicated that voice misidentifications occur, with many errors due to confusions of high‐typical voice targets with high‐typical target voices. The results show that voice typicality affects voice recognition accuracy and is an important factor to be considered in real‐life earwitness testimony situations. Copyright © 2009 John Wiley & Sons, Ltd.     

Commonsense beliefs and the identification of familiar voices

Two experiments are reported in which participants attempted to reject the tape‐recorded voice of a stranger and identify by name the voices of three personal associates who differed in their level of familiarity. In Experiment 1 listeners were asked to identify speakers as soon as possible, but were not allowed to change their responses once made. In Experiment 2 listeners were permitted to change their responses over successive presentations of increasing durations of voice segments. Also, in Experiment 2 half of the listeners attempted to identify speakers who spoke in normal‐tone voices, and the remainder attempted to identify the same speakers who spoke in whispers. Separate groups of undergraduate students attempted to predict the performance of the listeners in both experiments. Accuracy of performance depended on the familiarity of speakers and tone of speech. A between‐subjects analysis of rated confidence was diagnostic of accuracy for high familiar and low familiar speakers (Experiment 1), and for moderate familiar and unfamiliar normal‐tone speakers (Experiment 2). A modified between‐subjects analysis assessed across the four levels of familiarity yielded reliable accuracy‐confidence correlations in both experiments. Beliefs about the accuracy of voice identification were inflated relative to the significantly lower actual performance for most of the normal‐tone and whispered‐speech conditions. Forensic significance and generalizations are addressed. Copyright © 2001 John Wiley & Sons, Ltd.     

The Effect of LPC Narrowband Processing and Bit Error Rate on Performance in a Sentence Verification Task

The comprehension of narrowband digital speech with bit errors was tested using a sentence verification task. The difficulty of the verification task was varied by using predicates that were either strongly or weakly related to the subjects (e.g., A toad has warts./A toad has eyes.). The test conditions included unprocessed speech and speech processed using a 2,400 bitdsec linear predictive coding (LPC) voice processing algorithm with random bit error rates of 0%, 2%, and 5%. In general, response accuracy decreased and reaction time (RT) increased with LPC processing and with increasing bit error rates. Weakly related true sentences and strongly related false sentences were more difficult than strongly related true sentences and weakly related false sentences, respectively. Interactions between sentence type and speech processing conditions are discussed. The longer time taken to react to degraded speech has implications for performance in military combat situa- tions where split-second decisions are required. The higher error rates with degraded sentences that contain little contextual information are particularly relevant to policy conversations that use a varied vocabulary.     

Explaining the persistence of false memories: a proposal based on associative activation and thematic extraction

This study aimed to analyse the effect of retention intervals on associative and thematic false memories. Two experiments, using two types of critical items that were either associatively or thematically related to studied material, were conducted. In both experiments, one group of participants performed a recognition test immediately after the presentation of lists, and another group performed the task one week later. In Experiment 1, the recognition test consisted of pairs of items with four response alternatives (both items had been presented, only the left item had been presented, only the right item had been presented or none of the items had been presented). Critical items were also manipulated so that they were either presented in or absent from the list. In Experiment 2, a standard recognition test that differed in the mode of presentation was used: self-paced or speeded response. Both experiments showed that associative critical items were more recognised than thematic critical items in the immediate condition. However, whereas associative critical items decayed after a one-week delay, thematic critical items were similarly recognised at both retention intervals. The findings of the present study suggest that each type of process – associative and thematic – behave differently over time.     

Walk for well-being: The main effects of walking on approach motivation

The purpose of this study was to investigate the role of exercise in the development of self-efficacy and approach motivation. An 8-week blind experimental design was used (N?=?185), with two control and two treatment groups. Already physically active participants were assigned to one control group, while participants that reported a sedentary lifestyle at pretest were randomly assigned to either a sedentary control group or one of two treatment groups that began a brisk walking intervention. Treatment group participants walked either outdoors or indoors for 30 min per day, 4 days per week, for 8 weeks. The indoor/outdoor treatment group assignment was implemented to determine if exercising outdoors enhanced the outcomes. Significant main effects of walking were found for exercise self-efficacy, general self-efficacy and global approach motivation tendencies. Walking outdoors resulted in the greatest gains in general self-efficacy and global approach motivation. Given the alarmingly sedentary nature of American culture, these findings further evidence how simple changes in physical activity may have profound effects on well-being.

     

Uniforms affect the accuracy of children's eyewitness identification decisions

A substantial proportion of line‐up identifications involving child eyewitnesses in the UK are conducted by police officers wearing uniform. This study examined the possibility that wearing a uniform constitutes an authority cue that adversely affects a child's ability to make accurate eyewitness identifications. Sixty participants aged 9–10 years old witnessed a staged crime and were later asked to identify a ‘burglar’ from a simultaneous line‐up using a 2 (uniform: present vs. absent) × 2 (target: present vs. absent) design. Children in the uniform present conditions made significantly more choices than children in the uniform absent conditions. More importantly, in the presence of a uniform, children made significantly more false identifications in target‐absent line‐ups. Analysis of supplementary, identification‐related variables (identification time and confidence, state anxiety) suggested that (1) the children experienced uncertainty if the target was absent from the line‐up, but (2) this uncertainty was not expressed when the line‐up administrator wore a uniform, leading to an increase in false identifications. Implications for line‐up administration procedures for children are discussed. Copyright © 2009 John Wiley & Sons, Ltd.     

Prospective memory in a language-trained chimpanzee (Pan troglodytes)

Prospective memory involves the encoding, retention, and implementation of an intended future action. Although humans show many forms of prospective memory, less is known about the future oriented processes of nonhuman animals, or their ability to use prospective memory. In this experiment, a chimpanzee named Panzee, who had learned to associate geometric forms called lexigrams with real-world referents, was given a prospective memory test. Panzee selected between two foods the one she wanted to receive more immediately. That food was scattered in an outdoor yard where she could forage for it. Also outdoors were lexigram tokens, one of which represented the food item that remained indoors throughout a 30 min period, and that could be obtained if Panzee brought in the token that matched that food item. After foraging for the selected food item, Panzee consistently remembered to retrieve and return the correct token when food was available indoors, whereas on control trials involving no indoor food she rarely returned a token. This indicated that Panzee encoded information relevant to the future action of token retrieval after extended delays for one type of food, even when a more immediately preferred food was available.