White Targets Research Articles

Performance Validation of a Multi-Channel LiDAR Sensor: Assessing the Effects of Target Height and Sensor Velocity on Measurement Error

Abstract. The objective of this study was to determine the effects of sensor velocity and target height above ground level on height measurement error when using a multi-channel LiDAR sensor. A linear motion system was developed to precisely control the dynamics of the LiDAR sensor in an effort to remove uncertainty in the LiDAR position and velocity while under motion. The linear motion system allowed the LiDAR to translate forward and backward in one direction parallel to the ground. A user control interface was developed to operate the system under different velocity profiles and to log LiDAR data synchronous to the motion of the system. The performance of the linear motion system was validated with a tracking total station, and the results showed that the position and velocity control errors were negligible as compared to the LiDAR accuracy. The LiDAR was then validated using 25 test targets at varying heights above ground level (0.1, 0.3, 0.5, 0.6, and 0.8 m) with five different velocity profiles (0.1, 0.5, 1.0, 1.5, and 2.2 m s-1) and six replications to determine the effects of sensor velocity and target height on measurement error. The targets were painted white on one side and black on the other to determine the effect of relative intensity on LiDAR height measurement error. Generalized linear mixed models were fitted with the measurement error and the standard deviation of the measurement error as the responses. Sensor velocity, target height, and their interaction were considered as fixed effects to determine if there were significant differences in average error and standard deviation of error for different sensor velocities and target heights. The results indicated that the velocity of the LiDAR was a significant factor affecting the average error and standard deviation of error in height measurements. However, higher velocities tended to result in only slightly larger average errors. A three-fold increase in the standard deviation was observed when increasing the velocity from 0.1 to 2.2 m s-1. Height of the target was either a weakly significant or insignificant factor in average error and a weakly significant factor affecting the standard deviation of the LiDAR measurements, representing mixed results. The average error and standard deviation were less than 10 and 30 mm, respectively, for all replications. Relative intensities of the LiDAR measurements were 88.2% and 5.4% for white and black targets, respectively, and the different target colors exhibited a 4.7 mm shift in average estimated height error. These uncertainties may not be substantial for agricultural applications, where other sources of error, such as moving crop canopies or error in resolving the position of the sensor, are more likely to dominate overall measurement error. Keywords: LiDAR, Measurement error, Precision agriculture, Remote sensing, Validation.

Your Name Is Your Lifesaver: Anglicization of Names and Moral Dilemmas in a Trilogy of Transportation Accidents

Can immigrants’ names determine whether they receive help or not? Drawing on a partial in-group membership framework, we adapted intergroup versions of moral dilemmas (a trilogy of transportation accidents) to test how Anglicizing ethnic names affects intergroup decision-making in hypothetical life-and-death situations. Study 1 showed that White American participants were equally likely to help White and Asian immigrants with Anglicized names but were less likely to help Asian immigrants with original ethnic names. The same effect emerged in Study 2 but only among male White American participants. In Study 3, White pro-assimilationists were more likely to help White than Arab immigrants (with either Anglicized or original ethnic names), but White pro-multiculturalists were more likely to help Arab immigrants with Anglicized names than White targets. The results suggest that name Anglicization as a cultural assimilation practice may reduce intergroup bias, but the precise pattern of effects is context-dependent.

Impact of higher-order aberrations on depth-of-field.

It is well known that depth-of-focus (DOF) is influenced by optical factors (such as pupil size and monochromatic aberrations). However, neural factors such as blur sensitivity and defocus adaptation may play an important role on the extent of DOF. A series of experiments were conducted to study if optical or neural factors are most pertinent in explaining the variability of DOF across subjects. An adaptive optics system with a black and white target, a 3.8-mm artificial pupil, and a subjective criterion (based on objectionable blur) were used to measure depth of field ([DOFi]; DOF computed in the object space) in 11 participants, after at least 6 min of adaptation. This was done under three conditions: (a) with their own higher order aberrations (HOA); (b) after correction of their monochromatic HOA; and (c) after altering the HOA pattern for some participants to reflect the HOA pattern measured for a different participant. Natural DOFi and DOFi after HOA correction were positively correlated (R2 = 0.461), but a significant decrease in DOFi (21% on average) was found after HOA correction (p = 0.042). Effect of HOA on the intersubject variability of DOFi was 3.9 times smaller than the effect of the image neural processing. This study shows that DOFi depends on both optical and neural factors, but the latter seems to play a more important role than the former.

Racialized images: Tracing appraisals of police force and protest.

As race acts as a social frame of reference, it should guide individual's appraisal of visual representations of social events and issues. Thus, grounded in Scherer's (2009) model of appraisal as a sequential process, in 2 experiments (N = 133, 166) we used early event-related potentials (ERPs) of brain activity (the N100, P200, P300) to examine Black and White participants' appraisals of the novelty of images of police force against Black (and White) targets, as well as of Black-led protest. We used a later ERP (the late positive potential, LPP) as well as blood pressure to assess their appraisal of motivational relevance, and self-reported affect and emotion to assess conscious experience. White participants' early ERPs suggested that they appraised the images as more novel than did Black participants. Nevertheless, Black participants' later (LPP) ERP, and blood pressure, suggested that they appraised the images as more motivationally relevant. Consistent with this, Black participants expressed more attentiveness, anger, and empowerment at the images, whereas White participants expressed more surprise. A mediation model in Experiment 2 showed that self-reported familiarity with past racial violence, as well as surprise and attentiveness to the images, explained the difference between Black and White participants' appraisals of motivational relevance (i.e., the LPP). We discuss implications for appraisal theory, stress and coping, and societally situated cognition and affect. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

Effects of a companion dog on associations of danger and threat with oriental‐looking targets

AbstractIn the current study we extend previous findings on the shooter bias toward targets with Arab ethnicity. In an adapted shooter task, we presented stereotypically oriental‐looking targets without explicit symbols of Islam (e.g., a turban) and additionally tested if presenting a “harmless” companion dog, together with Arab versus White targets, would affect the shooter bias. Participants responded faster and made fewer errors for armed Arab than for armed White targets. Moreover, compared to the “neutral” no dog condition, the presence of a dog triggered fewer false alarms for White than for Arab targets and slowed down (correct) responses in general. Implications and potential underlying mechanisms are discussed.

Implicit Bias Predicts Liking of Ingroup Members Who Are Comfortable With Intergroup Interaction.

We test a novel framework for how ingroup members are perceived during intergroup interaction. Across three experiments, we found that, above and beyond egalitarian attitudes and motivations, White observers' automatic responses to Blacks (i.e., their implicit anti-Black bias) shaped their affiliation toward ingroup targets who appeared comfortable engaging in interracial versus same-race interaction. White observers' implicit anti-Black bias negatively correlated with liking of White targets who were comfortable with Blacks (Experiments 1-3). The relationship between implicit bias and liking varied as a function of targets' nonverbal comfort in interracial interactions (Experiment 1). Specifically, implicit bias negatively correlated with liking of targets when targets' nonverbal behaviors revealed observers felt comfortable with interracial contact, irrespective of the nature of those behaviors (Experiment 2). Finally, the relationship between implicit bias and target liking was mediated by perceived similarity (Experiment 3). Theoretical implications for stigma-by-association, social network homogeneity, and extended contact are discussed.

Gatecrashing the visual cocktail party: How visual and semantic similarity modulate the own name benefit in the attentional blink.

The "visual cocktail party effect" refers to superior report of a participant's own name, under conditions of inattention. An early selection account suggests this advantage stems from enhanced visual processing. A late selection account suggests the advantage occurs when semantic information allowing identification as one's own name is retrieved. In the context of inattentional blindness (IB), Mack and Rock showed that the advantage does not generalise to a minor modification of a participant's own name, despite extensive visual similarity, supporting the late selection account. This study applied the name modification manipulation in the context of the attentional blink (AB). Participants were presented with rapid streams of names and identified a white target name, while also reporting the presence of one of two possible probes. The probe names appeared either close (the third item following the target: Lag 3) or far in time from the target (the eighth item following the target: Lag 8). The results revealed a robust AB; reports of the probe were reduced at Lag 3 relative to Lag 8. The AB was also greatly reduced for the own name compared to another name-a visual cocktail party effect. In contrast to the findings of Mack and Rock for IB, the reduced AB extended to the modified own name. The results suggest different loci for the visual cocktail party effect in the AB (word recognition) compared to IB (semantic processing).

Socioeconomic status is not judged equally: Target race shifts standards in interpersonal judgments of SES

AbstractAcross three studies, respondents made SES judgments of targets varying in Race (White or Black) and SES (Low or High), including global subjective SES, financial success, and educational attainment. As Whites and Blacks are stereotypically associated with upper and lower SES, respectively, the Shifting Standards Model (SSM) of stereotype judgments predicted the pattern of interpersonal objective and subjective judgments. In Study 1, in a between‐subjects design, respondents rated Black targets significantly higher on subjective measures than White targets, even as the targets were rated as comparable on objective measures. Study 2 replicated these effects with a broader range of stimulus materials. In Study 3, the shifting standards effect was replicated using a within‐subjects design, further supporting the effect. The findings support the application of the SSM to race‐based shifts in interpersonal judgments of SES and are discussed regarding their implications for intergroup relations and workplace evaluations.

Validation and Application of the LS/CMI in Nebraska Probation

This study examined the validity of the Level of Service/Case Management Inventory (LS/CMI), as probation officers in the state of Nebraska use the tool. Study 1 evaluated the predictive validity of the LS/CMI by examining 19,344 probationer records over a 5.5-year period (January 2007-July 2013), and found that the LS/CMI total risk score demonstrated moderate predictive validity. Consistent with past findings, logistic regression showed that the total risk score predicted recidivism (return to probation) differently for nonminorities than for minorities. Furthermore, minorities scored higher than nonminorities on seven of the eight criminogenic factors. Study 2, a true randomized experiment, explored probation officer bias as an explanation for these findings, and found that training increased officers’ ratings of scores in some LS/CMI domains and decreased ratings in others. Most importantly, there was no evidence that officers demonstrated racial bias in administering the LS/CMI survey when scoring Black versus White target clients.

Eye Movement Control in the Argus II Retinal-Prosthesis Enables Reduced Head Movement and Better Localization Precision.

Visual scanning by sighted individuals is done using eye and head movements. In contrast, scanning using the Argus II is solely done by head movement, since eye movements can introduce localization errors. Here, we tested if a scanning mode utilizing eye movements increases visual stability and reduces head movements in Argus II users. Eye positions were measured in real-time and were used to shift the region of interest (ROI) that is sent to the implant within the wide field of view (FOV) of the scene camera. Participants were able to use combined eye-head scanning: shifting the camera by moving their head and shifting the ROI within the FOV by eye movement. Eight blind individuals implanted with the Argus II retinal prosthesis participated in the study. A white target appeared on a touchscreen monitor and the participants were instructed to report the location of the target by touching the monitor. We compared the spread of the responses, the time to complete the task, and the amount of head movements between combined eye-head and head-only scanning. All participants benefited from the combined eye-head scanning mode. Better precision (i.e., narrower spread of the perceived location) was observed in six out of eight participants. Seven of eight participants were able to adopt a scanning strategy that enabled them to perform the task with significantly less head movement. Integrating an eye tracker into the Argus II is feasible, reduces head movements in a seated localization task, and improves pointing precision.

Black and White discrimination in the United States: Evidence from an archive of survey experiment studies

This study reports results from a new analysis of 17 survey experiment studies that permitted assessment of racial discrimination, drawn from the archives of the Time-sharing Experiments for the Social Sciences. For White participants (n=10 435), pooled results did not detect a net discrimination for or against White targets, but, for Black participants (n=2781), pooled results indicated the presence of a small-to-moderate net discrimination in favor of Black targets; inferences were the same for the subset of studies that had a political candidate target and the subset of studies that had a worker or job applicant target. These results have implications for understanding racial discrimination in the United States, and, given that some of the studies have never been fully reported on in a journal or academic book, the results also suggest the need for preregistration to reduce or eliminate publication bias in racial discrimination studies.

Emotional Congruence and Judgments of Honesty and Bias

Psychological and philosophical discussions typically understand honesty as reporting truth with propositional statements. In this model, emotions are often seen as irrelevant or a hindrance to honesty, because they can bias our reports. In relational contexts, however, emotions can provide information about deep-seated convictions. We report the results of a study (N = 827) finding that individuals whose emotional responses are congruent with their explicitly stated egalitarian positions are judged as significantly more honest and less prejudiced than those with incongruent emotional responses. This is seen in judgments of white male targets who have negative emotional responses to a black man, a gay man, and a female supervisor. These results suggest that emotional reactions provide information used when judging the honesty and bias of an individual.

Simplified radiometric calibration for UAS-mounted multispectral sensor

ABSTRACTUnmanned aircraft system (UAS) in combination with multispectral sensors stimulate the utilisation of site-specific technologies to manage crop production according to intrafield variability. Crop monitoring requires accurate calibration. However, radiometric calibration methods in practice are difficult to implement for UAS remote sensing as every single image requires correction due to smaller field of view and changes in light. Therefore, this paper proposes an easy radiometric calibration process for UAS-based miniature multiple camera array multispectral sensor. Results showed linear relationship between spectral reflectance and raw DN values with y-intercept value compatible with zero. It is the minimal possible surface reflectance recorded by sensor and can be used as a first point for equation development. The spectral quantification of white pseudo target was used as a second point of equation. Quantitative spectral information was generated by developing equation for every single image. An accuracy assessment was undertaken by comparing image-driven reflectance values against reflectance values measured in the field from soil and crop. The overall accuracy based on the root mean square error for the six bands ranged from 0.025% to 0.064%. The results of this study showed that the proposed method can be used for the calibration of UAS-based multispectral image .

Racial bias in sport medical staff’s perceptions of others’ pain

ABSTRACTUnequal treatment based on race is well documented in higher education and healthcare settings. In the present work, we examine racial bias at the intersection of these domains: racial bias in pain-related perceptions among National Collegiate Athletic Association (NCAA) Division 1 sport medical staff. Using experimental vignettes about a student-athlete who injured his/her anterior cruciate ligament (ACL), we find, like prior work, that respondents perceived Black (vs. White) targets as having higher initial pain tolerance. Moreover, this bias was mediated by perceptions of social class. We extend prior work by showing racial bias was not evident on other outcome measures, including perception of recovery process pain, likelihood of over-reporting pain, and over-use of drugs to combat pain. This suggests stricter boundary conditions on bias in pain perceptions than had been previously recognized.

White House Opioid Commission Targets Trouble Spots, Misses Some

White House Opioid Commission Targets Trouble Spots, Misses Some

What Influences Shooter Bias? The Effects of Suspect Race, Neighborhood, and Clothing on Decisions to Shoot

AbstractPolice shooting deaths of unarmed Blacks and African Americans led to psychological research on the influence of racial stereotypes on decisions to shoot, an effect called shooter bias. This article investigates how contextual cues signaling threat or safety interact with the race of the target to moderate shooter bias. Across two experimental studies using a first person shooter task, participants viewed Black or White male targets who held either a neutral (wallet or cellphone) or dangerous (gun) object. Study 1 manipulated the perceived safety or threat associated with the neighborhood context these shooting decisions occurred in, and Study 2 manipulated the perceived safety or threat associated with the targets’ clothing. Participants made quick decisions to “shoot” or “not shoot” the presented target, with error rates serving as the dependent variable. Across both studies, results confirmed that racial bias in shooting decisions against Blacks was present in perceived threatening neighborhoods and in perceived threatening clothing, and it was reduced in perceived safe neighborhoods and when wearing perceived safe clothing. Results help to identify contextual factors that may lead to mistaken shooting decisions, which can be used to improve police training and decision making to reduce bias.

External motivation to avoid prejudice alters neural responses to targets varying in race and status.

Those who are high in external motivation to respond without prejudice (EMS) tend to focus on non-racial attributes when describing others. This fMRI study examined the neural processing of race and an alternative yet stereotypically relevant attribute (viz., socioeconomic status: SES) as a function of the perceiver’s EMS. Sixty-one White participants privately formed impressions of Black and White faces ascribed with high or low SES. Analyses focused on regions supporting race- and status-based reward/salience (NAcc), evaluation (VMPFC) and threat/relevance (amygdala). Consistent with previous findings from the literature on status-based evaluation, we observed greater neural responses to high-status (vs low-status) targets in all regions of interest when participants were relatively low in EMS. In contrast, we observed the opposite pattern when participants were relatively high in EMS. Notably, all effects were independent of target race. In summary, White perceivers’ race-related motivations similarly altered their neural responses to the SES of Black and White targets. Specifically, the findings suggest that EMS may attenuate the positive value and/or salience of high status in a mixed-race context. Findings are discussed in the context of the stereotypic relationship between race and SES.

Effects of exposure to alcohol‐related cues on racial discrimination

AbstractPrior research has shown that exposure to alcohol‐related images exacerbates expression of implicit racial biases, and that brief exposure to alcohol‐related words increases aggressive responses. However, the potential for alcohol cue exposure to elicit differential aggression against a Black (outgroup) relative to a White (ingroup) target—that is, racial discrimination—has never been investigated. Here, we found that White participants (N = 92) exposed to alcohol‐related words made harsher judgments of a Black experimenter who had frustrated them than participants who were exposed to nonalcohol words. These findings suggest that exposure to alcohol cues increases discriminatory behaviors toward Blacks.

Rapid Processing of a Global Feature in the ON Visual Pathways of Behaving Monkeys

Visual objects are recognized by their features. Whereas, some features are based on simple components (i.e., local features, such as orientation of line segments), some features are based on the whole object (i.e., global features, such as an object having a hole in it). Over the past five decades, behavioral, physiological, anatomical, and computational studies have established a general model of vision, which starts from extracting local features in the lower visual pathways followed by a feature integration process that extracts global features in the higher visual pathways. This local-to-global model is successful in providing a unified account for a vast sets of perception experiments, but it fails to account for a set of experiments showing human visual systems' superior sensitivity to global features. Understanding the neural mechanisms underlying the “global-first” process will offer critical insights into new models of vision. The goal of the present study was to establish a non-human primate model of rapid processing of global features for elucidating the neural mechanisms underlying differential processing of global and local features. Monkeys were trained to make a saccade to a target in the black background, which was different from the distractors (white circle) in color (e.g., red circle target), local features (e.g., white square target), a global feature (e.g., white ring with a hole target) or their combinations (e.g., red square target). Contrary to the predictions of the prevailing local-to-global model, we found that (1) detecting a distinction or a change in the global feature was faster than detecting a distinction or a change in color or local features; (2) detecting a distinction in color was facilitated by a distinction in the global feature, but not in the local features; and (3) detecting the hole was interfered by the local features of the hole (e.g., white ring with a squared hole). These results suggest that monkey ON visual systems have a subsystem that is more sensitive to distinctions in the global feature than local features. They also provide the behavioral constraints for identifying the underlying neural substrates.

Black and White Lies: Race-Based Biases in Deception Judgments

In six studies (N = 605), participants made deception judgments about videos of Black and White targets who told truths and lies about interpersonal relationships. In Studies 1a, 1b, 1c, and 2, White participants judged that Black targets were telling the truth more often than they judged that White targets were telling the truth. This truth bias was predicted by Whites’ motivation to respond without prejudice. For Black participants, however, motives to respond without prejudice did not moderate responses (Study 2). In Study 3, we found similar effects with a manipulation of the targets’ apparent race. Finally, in Study 4, we used eye-tracking techniques to demonstrate that Whites’ truth bias for Black targets is likely the result of late-stage correction processes: Despite ultimately judging that Black targets were telling the truth more often than White targets, Whites were faster to fixate on the on-screen “lie” response box when targets were Black than when targets were White. These systematic race-based biases have important theoretical implications (e.g., for lie detection and improving intergroup communication and relations) and practical implications (e.g., for reducing racial bias in law enforcement).