Tell me what you saw: The usefulness of verbal descriptions for others

2020 ◽  
Vol 73 (8) ◽  
pp. 1227-1241
Author(s):  
Deborah H Tan ◽  
Yuhong V Jiang
Keyword(s):  
Visual Memory ◽  
Eyewitness Identification ◽  
High Capacity ◽  
Target Object ◽  
Identification Accuracy ◽  
Common Source ◽  
Visual Objects ◽  
Verbal Descriptions ◽  
Common Memory ◽  
Basic Level

Describing what one saw to another person is common in everyday experience, such as spatial navigation and crime investigations. Past studies have examined the effects of recounting on one’s own memory, neglecting an important function of memory recall in social communication. Here we report surprisingly low utility of one’s verbal descriptions for others, even when visual memory for the stimuli has high capacity. Participants described photographs of common objects they had seen to enable judges to identify the target object from a foil in the same basic-level category. When describing from perception, participants were able to provide useful descriptions, allowing judges to accurately identify the target objects 87% of the time. Judges’ accuracy decreased to just 57% when participants provided descriptions from memory acquired minutes ago, and to near chance (51.8%) when the verbal descriptions were based on memory acquired 24 hours ago. Comparison of participants’ own identification accuracy with judges’ accuracy suggests the presence of a common source of errors. This finding suggests that recall and recognition of visual objects share common memory sources. In addition, the low utility of one’s verbal descriptions constrains theories about the extension of one’s memory to the external world and has implications for eyewitness identification and laws governing it.

Spherical object recognition based on the number of contour edges extracted by fitting and convex hull processing

2020 ◽  
pp. 095440702096950
Author(s):  
Bochang Zou ◽  
Huadong Qiu ◽  
Yufeng Lu
Keyword(s):  
Convex Hull ◽  
Target Object ◽  
Identification Accuracy ◽  
Detection Accuracy ◽  
Morphological Operations ◽  
Circle Detection ◽  
Spherical Object ◽  
Single Feature ◽  
Contour Fitting ◽  
Rgb Images

The detection of spherical targets in workpiece shape clustering and fruit classification tasks is challenging. Spherical targets produce low detection accuracy in complex fields, and single-feature processing cannot accurately recognize spheres. Therefore, a novel spherical descriptor (SD) for contour fitting and convex hull processing is proposed. The SD achieves image de-noising by combining flooding processing and morphological operations. The number of polygon-fitted edges is obtained by convex hull processing based on contour extraction and fitting, and two RGB images of the same group of objects are obtained from different directions. The two fitted edges of the same target object obtained at two RGB images are extracted to form a two-dimensional array. The target object is defined as a sphere if the two values of the array are greater than a custom threshold. The first classification result is obtained by an improved K-NN algorithm. Circle detection is then performed on the results using improved Hough circle detection. We abbreviate it as a new Hough transform sphere descriptor (HSD). Experiments demonstrate that recognition of spherical objects is obtained with 98.8% accuracy. Therefore, experimental results show that our method is compared with other latest methods, HSD has higher identification accuracy than other methods.

scholarly journals Eyewitness identification performance is not affected by time-of-day optimality

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Sergii Yaremenko ◽  
Melanie Sauerland ◽  
Lorraine Hope
Keyword(s):  
Eyewitness Identification ◽  
Time Of Day ◽  
Decision Time ◽  
Identification Accuracy ◽  
Optimal Time ◽  
Identification Performance ◽  
Accurate Identification ◽  
Facial Stimuli ◽  
Time Accuracy ◽  
Accuracy Relationship

AbstractThe circadian rhythm regulates arousal levels throughout the day and determines optimal periods for engaging in mental activities. Individuals differ in the time of day at which they reach their peak: Morning-type individuals are at their best in the morning and evening types perform better in the evening. Performance in recall and recognition of non-facial stimuli is generally superior at an individual’s circadian peak. In two studies (Ns = 103 and 324), we tested the effect of time-of-testing optimality on eyewitness identification performance. Morning- and evening-type participants viewed stimulus films depicting staged crimes and made identification decisions from target-present and target-absent lineups either at their optimal or non-optimal time-of-day. We expected that participants would make more accurate identification decisions and that the confidence-accuracy and decision time-accuracy relationships would be stronger at optimal compared to non-optimal time of day. In Experiment 1, identification accuracy was unexpectedly superior at non-optimal compared to optimal time of day in target-present lineups. In Experiment 2, identification accuracy did not differ between the optimal and non-optimal time of day. Contrary to our expectations, confidence-accuracy relationship was generally stronger at non-optimal compared to optimal time of day. In line with our predictions, non-optimal testing eliminated decision-time-accuracy relationship in Experiment 1.

scholarly journals The Effect of Pre-Event Instructions on Eyewitness Identification Stage 1 Registered Report Manuscript

2021 ◽  
Author(s):  
Mario J. Baldassari ◽  
Kara N. Moore ◽  
Ira Hyman ◽  
LORRAINE HOPE ◽  
Eric Mah ◽  
...  
Keyword(s):  
Systematic Review ◽  
Exposure Duration ◽  
Eyewitness Identification ◽  
Identification Accuracy ◽  
Identification Performance ◽  
Identification Stage ◽  
Lineup Identification ◽  
Stage 1 ◽  
Future Work

Research on eyewitness identification often involves exposing participants to a simulated crime and later testing memory using a lineup. We conducted a systematic review showing that pre-event instructions, instructions given before event exposure, are rarely reported and those that are reported vary in the extent to which they warn participants about the nature of event or tasks. At odds with the experience of actual witnesses, some studies use pre-event instructions explicitly warning participants of the upcoming crime and lineup task. Both the basic and applied literature provide reason to believe that pre-event instructions may impact eyewitness identification performance. In Experiment 1, we will test the effect of pre-event instructions on lineup identification decisions and confidence. Participants will receive non-specific pre-event instructions (i.e., “watch this video”) or eyewitness pre-event instructions (i.e., “watch this crime video, you’ll complete a line-up later”) and complete a culprit absent or present lineup. In Experiment 2, we will manipulate exposure duration and pre-event instructions to determine if pre-event instructions differentially impact high or low quality eyewitness events. If pre-event instructions impact eyewitness identification accuracy, then the findings of existing studies need to be considered in the context of their pre-event instructions and future work will be needed to determine how instructions interact with existing systems and estimator variables.

scholarly journals Digital Detectives: Websleuthing Reduces Eyewitness Identification Accuracy in Police Lineups

2021 ◽  
Vol 12 ◽  
Author(s):  
Camilla Elphick ◽  
Richard Philpot ◽  
Min Zhang ◽  
Avelie Stuart ◽  
Graham Pike ◽  
...  
Keyword(s):  
Social Media ◽  
Eyewitness Identification ◽  
Identification Accuracy ◽  
Directed Search ◽  
Filler Task ◽  
Online Study ◽  
Social Media Site ◽  
Police Lineup ◽  
Mock Crime ◽  
Lineup Identification

Eyewitnesses to crimes sometimes search for a culprit on social media before viewing a police lineup, but it is not known whether this affects subsequent lineup identification accuracy. The present online study was conducted to address this. Two hundred and eighty-five participants viewed a mock crime video, and after a 15–20 min delay either (i) viewed a mock social media site including the culprit, (ii) viewed a mock social media site including a lookalike, or (iii) completed a filler task. A week later, participants made an identification from a photo lineup. It was predicted that searching for a culprit on social media containing the lookalike (rather than the culprit) would reduce lineup identification accuracy. There was a significant association between social media exposure and lineup accuracy for the Target Present lineup (30% more of the participants who saw the lookalike on social media failed to positively identify the culprit than participants in the other conditions), but for the Target Absent lineup (which also included the lookalike) there was no significant association with lineup identification accuracy. The results suggest that if an eyewitness sees a lookalike (where they are expecting to see the culprit) when conducting a self-directed search on social media, they are less likely to subsequently identify the culprit in the formal ID procedure.

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