Dissecting the time course of person recognition in natural viewing environments

Person recognition often unfolds over time and distance as a person approaches, with the quality of identity information from faces, bodies, and motion in constant flux. Participants were familiarized with identities using close‐up and distant videos. Recognition was tested with videos of people approaching from a distance. We varied the timing of prompted responses in the test videos, the amount of video seen, and whether the face, body, or whole person was visible. A free response condition was also included to allow participants to respond when they felt ‘confident’. The pattern of accuracy across conditions indicated that recognition judgments were based on the most recently available information, with no contribution from qualitatively diverse and statistically useful person cues available earlier in the video. Body recognition was stable across viewing distance, whereas face recognition improved with proximity. The body made an independent contribution to recognition only at the farthest distance tested. Free response latencies indicated meta‐knowledge of the optimal proximity for recognition from faces versus bodies. Notably, response bias varied strongly as a function of participants’ expectation about whether closer proximity video was forthcoming. These findings lay the groundwork for developing person recognition theories that generalize to natural viewing environments.     

注意促进运动知觉判断的时间进程

本研究通过控制深度视觉线索, 分析3D SFM (structure from motion)知觉中的眼动特征, 探讨注意对SFM知觉判断的影响及其时间进程。结果显示, 有线索刺激比模糊刺激的判断更加快、更加肯定(百分比更高); 眼睛移动方向和微眼跳方向都分别与知觉判断的运动方向具有一致性; 微眼跳频次、峰速度和幅度也都分别表现出深度线索的促进效应。实验结果表明, SFM知觉过程大致分为速度计算和构建三维结构两个阶段; 注意对SFM知觉的调节作用主要发生在构建三维结构阶段; 注意从150 ms开始指向选择对象, 驻留持续约200 ms后, 从局部运动矢量流转移到整体运动方向的知觉判断。     

Post-traumatic stress symptoms of children and adolescents exposed to the 2008 Wenchuan Earthquake: A longitudinal study of 5-HTTLPR genotype main effects and gene–environment interactions

Experiencing disasters causes severe mental disorders, among which post-traumatic stress disorder (PTSD) is the most common. We conducted a longitudinal study to examine the effect of 5-hydroxyl tryptamine transporter gene-linked polymorphic region (5-HTTLPR) genotype on child and adolescent PTSD symptom course after the 2008 Wenchuan Earthquake. We genotyped 963 participants who personally experienced the earthquake. PTSD symptoms were measured by University of California, Los Angeles PTSD reaction index at 2.5, 3.5, 4.5 and 5.5 years after the earthquake, respectively. Latent growth model was utilised to examine the main effect and gene–environment interaction effect of 5-HTTLPR on PTSD's symptom course. 5-HTTLPR genotype predicted initial PTSD symptom severity (β = 0.108, p = .019) and rates of symptom recovery (β = −0.120, p = .031) between 2.5 and 5.5 years. Compared with L′ allele carriers, those with S′S′ genotype showed higher initial symptom severity but also faster recovery rate. 5-HTTLPR genotype only predicted symptom severity at 2.5 years after the earthquake, after controlling for sex, age, ethnicity and trauma severity (β = 0.108, p = .019). This is the first evidence of the effect of 5-HTTLPR genotype on child and adolescent PTSD symptoms longitudinally, offering a novel perspective on the effect of 5-HTTLPR on PTSD symptom development following trauma exposure.     

Functional Equivalence of Sleep Loss and Time on Task Effects in Sustained Attention

Research on sleep loss and vigilance both focus on declines in cognitive performance, but theoretical accounts have developed largely in parallel in these two areas. In addition, computational instantiations of theoretical accounts are rare. The current work uses computational modeling to explore whether the same mechanisms can account for the effects of both sleep loss and time on task on performance. A classic task used in the sleep deprivation literature, the Psychomotor Vigilance Test (PVT), was extended from the typical 10‐min duration to 35 min, to make the task similar in duration to traditional vigilance tasks. A computational cognitive model demonstrated that the effects of time on task in the PVT were equivalent to those observed with sleep loss. Subsequently, the same mechanisms were applied to a more traditional vigilance task—the Mackworth Clock Task—providing a good fit to existing data. This supports the hypothesis that these different types of fatigue may produce functionally equivalent declines in performance.     

Échelle de temporalité : validation française d’une version courte de la Zimbardo Time Perspective Inventory (ZTPI)

Lewin (1951, p. 75) defined time perspective as the “totality of the individual's view of his psychological future and psychological past existing at a given time”. Indeed, time perspective is considered to guide behaviors and participate in the construction of personal identity. The Zimbardo Time Perspective Inventory (ZTPI) was constructed by Zimbardo and Boyd (1999) to measure the five dimensions of time perspective (Past-Negative, Past-Positive, Present-Hedonistic, Present-Fatalistic and Future scales) and contained fifty-six items. The ZTPI was validated in more than twenty countries, as well in France (Apostolidis and Fieulaine, 2004) and a short version (15-25 items) was also studied in numerous cultural settings like in USA, Australia and various European countries. Nevertheless, the short version of the ZTPI has never been validated in French. The aim of this study is to validate a brief French measure of the ZTPI (Zimbardo and Boyd, 1999) in order to apply it to adults of all ages. Based on the long ZTPI (fifty-four items) validated by Apostolidis and Fieulaine (2004), we tested a version containing fifteen items, the ZTPI-15, among 466 adults (18-98 years). The exploratory analysis revealed a factorial structure representing five factors comprising three items for each scale. The model was tested through a confirmatory factorial analysis, showing that the ZTPI-15 fit indices were satisfactory (χ²/dl = 2.58, RMSEA =.066, CFI = .90, AGFI =.90, RMSR = .067). Internal consistency and test-retest reliability was verified. Correlations between mean scores of the five factors showed relationships. Present-Fatalistic was related to Past-Negative (r =.23) and to Future (r = −.20), whereas a correlation between Past-Negative and Future (r = −.22) was demonstrated. Moreover, Future related to Past-Positive (r =.12). Age was associated to all scales of the ZTPI-15 and the strongest correlation was to Present-Hedonistic (r = −.31). The comparison between 253 young adults (M = 22.5 years) and 160 older adults (M = 73.3 years) showed that the older were less oriented to Past-Negative and Present-Hedonistic but more to Past-Positive, Present-Fatalistic and Future. Furthermore, educational level was correlated to Fatalistic-Present (r = −.28). The validity of the ZTPI-15 was also confirmed with the scores of anxiety and depression and with the Self-Esteem Scale: individuals with high score of anxiety were oriented to Past-Negative (r = .34) and those with high score of depression were oriented to past-Negative (r = .27) and Fatalistic-Present (r = .27). Finally, individuals with low self-esteem were strongly oriented to Past-Negative (r = −.45) and Present-Fatalistic (r = −.27), and individuals with high self-esteem to Future (r = .28).     

Impact of time pressure on acceleration behavior and crossing decision at the onset of yellow signal

This study investigates acceleration behavior and crossing decision of the drivers under increasing time pressure driving conditions. A typical urban route was designed in a fixed-base driving simulator consisting of four signalized intersections with varying time to stop line (4 s and 6 s) and maneuver type (right-turn and go-through). 97 participants’ data were obtained under No Time Pressure (NTP), Low Time Pressure (LTP), and High Time Pressure (HTP) driving conditions. The acceleration behavior was examined at the onset of yellow signal in four ways: continuous deceleration, acceleration-deceleration, deceleration-acceleration, and continuous acceleration. A random forest model was used to build an acceleration behavior prediction model for identifying the significant explanatory variables based on variable importance ranking. Further, a Mixed Effects Multinomial Logit (MEML) model was developed using the explanatory variables obtained from a random forest model. Additionally, a generalized linear mixed model was incorporated for estimating the likelihood of crossing an intersection by considering all the explanatory variables. A MEML model result revealed that the odds of adopting acceleration-deceleration, deceleration-acceleration, and continuous acceleration instead of continuous deceleration increased by 63 %, 123 %, and 77 %, respectively under HTP driving conditions. Moreover, the likelihood of crossing a signalized intersection increased by 2.73 times and 4.26 times when the drivers were under LTP and HTP driving conditions, respectively as compared to NTP driving condition. Apart from this, time to stop line (reference: 6 s) and age showed negative association with crossing probability. Overall, the findings from this study revealed that drivers altered their acceleration behavior for executing risky driving decisions under increasing time pressure driving conditions.     

Feedback frequency of graphical countdown timers affects pedestrian estimated waiting time at red lights

Graphical countdown timers (similar to a progress bar) have the potential to shorten pedestrians’ perceived waiting time at the red light. Based on the findings from human-computer interaction (HCI) and time estimation theories, the potential may be affected by feedback frequency. This study tested how the feedback frequency of countdown progress bar in traffic light influenced time estimation in a field experiment, and further explored its mechanism in a laboratory experiment. In both experiments, participants estimated various durations (30 s, 45 s, 60 s) under three levels of feedback frequency: low (0.5 Hz), medium (1 Hz), and high (2 Hz). The results showed that although waiting time was underestimated in all conditions, lower feedback frequency led to shorter estimated duration, with slight changes in different contexts. In the traffic context, the effect of feedback frequency was comparable across different countdown duration, but it became stronger at longer countdown duration in the non-traffic context. Overall, the effect of feedback frequency was accompanied by changes in neither arousal level (measured by the subjective scale and physiological indices) nor internal clock speed, which are two critical determinants of time perception. The findings have practical implications on the display design of red light and theoretical implications on time estimation processes.     

Exploring behavioral validity of driving simulator under time pressure driving conditions of professional drivers

Driving simulators have become an important tool in human factors research, given that they are appropriately validated. Therefore, this study aims to explore the behavioral (absolute and relative) validity of a fixed-base driving simulator by analyzing different driving behavior measures such as speed, longitudinal acceleration, lateral acceleration, and brake pedal force. Thirty professional drivers participated in the experiment and the data was collected in real and simulated worlds under No Time Pressure (NTP) and Time Pressure (TP) driving conditions. Initially, comparative analyses were conducted on different driving behavior measures using Wilcoxon-signed rank test to examine absolute validity of the driving simulator. Finally, Generalized Linear Mixed (GLM) models were developed for computing the effective distance between real and simulated worlds by quantifying the parameters and for establishing relative validity. In general, the continuous profiles of driving behavior measures followed similar trends in real and simulated worlds and comparative analyses indicated relative validity of the driving simulator. The GLM models showed significant interaction effect of driving environments (real-world and simulated world) and driving conditions (NTP and TP) where high driving speed, high brake pedal force, and low lateral acceleration were observed in simulated world under TP driving condition than real-world under TP driving condition. Overall, the statistical analyses showed qualitative correspondence (relative validity) of the driving behavior measures in between real and simulated worlds. The findings from the current study showed expediency of the driving simulator and its effectiveness in conducting research on human factors and driver safety.