Continuous dynamics in the real-time perception of race

Although the outcomes of race categorization have been studied in detail, the temporal dynamics of real-time processing of race remain elusive. We measured participants’ hand movements en route to one of two race-category alternatives by recording the streaming x, y coordinates of the computer mouse. Study 1 showed that, when categorizing White and Black computer-generated faces that featurally overlapped with the opposite race, mouse trajectories showed a continuous spatial attraction toward the opposite category. Moreover, these race-atypical White and Black targets induced spatial attraction effects that had different temporal signatures. Study 2 showed that, when categorizing real faces that varied along a continuum of racial ambiguity, graded increases in ambiguity led to corresponding increases in trajectories’ attraction to the opposite category and trajectories’ movement complexity. These studies provide evidence for temporally dynamic competition across perceptions of race, where simultaneously and partially-active race categories continuously evolve into single categorical outcomes over time. Moreover, the findings show how different social category cues may exert different dynamic patterns of influence over the real-time processing that culminates in categorizations of others.     

Planning for the near and distant future: How does temporal distance affect task completion predictions?

In everyday life people estimate completion times for projects in the near and distant future. How might the temporal proximity of a project influence prediction? Given that closer events elicit more concrete construals, we proposed that temporal proximity could enhance two kinds of concrete cognitions pertinent to task completion predictions: step-by-step plans and potential obstacles. Although these cognitions have opposite implications for prediction, and thus could cancel each other out, we hypothesized that temporal proximity would have a greater impact on cognitions that were relatively focal. Thus contextual factors that alter the relative focus on plans vs. obstacles should determine whether and how temporal proximity affects prediction. Six studies supported this reasoning. In contexts that elicited a focus on planning, individuals predicted earlier completion times for close than distant projects. In contexts that prompted a focus on obstacles, individuals predicted later completion times for close than distant projects.     

Temporal processing capabilities in repetition conduction aphasia

This study investigates the temporal resolution capacities of the central-auditory system in a subject (NP) suffering from repetition conduction aphasia. More specifically, the patient was asked to detect brief gaps between two stretches of broadband noise (gap detection task) and to evaluate the duration of two biphasic (WN-3) continuous noise elements, starting with white noise (WN) followed by 3 kHz bandpass-filtered noise (duration discrimination task). During the gap detection task, the two portions of each stimulus were either identical (“intra-channel condition”) or differed (“inter-channel condition”) in the spectral characteristics of the leading and trailing acoustic segments. NP did not exhibit any deficits in the intra-channel condition of the gap detection task, indicating intact auditory temporal resolution across intervals of 1–3 ms. By contrast, the inter-channel condition yielded increased threshold values. Based upon the “multiple-looks” model of central-auditory processing, this profile points at a defective integration window operating across a few tens of milliseconds – a temporal range associated with critical features of the acoustic speech signal such as voice onset time and formant transitions. Additionally, NP was found impaired during a duration discrimination task addressing longer integration windows (ca. 150 ms). Concerning speech, this latter time domain approximately corresponds to the duration of stationary segmental units such as fricatives and long vowels. On the basis of our results we suggest, that the patient’s auditory timing deficits in non-speech tasks may account, at least partially, for his impairments in speech processing.     

Using temporal logics of knowledge for specification and verification—a case study

Temporal logics of knowledge are useful for reasoning about situations where the knowledge of an agent or component is important, and where change in this knowledge may occur over time. Here we use temporal logics of knowledge to reason about the game Cluedo. We show how to specify Cluedo using temporal logics of knowledge and prove statements about the knowledge of the players using a clausal resolution calculus for this logic. We discuss the advantages and disadvantages of using this logic to specify and verify the game Cluedo and describe related implementations.     

Infant-adult vocal interaction dynamics depend on infant vocal type,child-directedness of adult speech,and timeframe

This study explored the temporal contingencies between infant and adult vocalizations as a function of the type of infant vocalization, whether adult caregivers’ vocalizations were infant-directed or other-directed, and the timescale of analysis. We analyzed excerpts taken from day-long home audio recordings that were collected from nineteen 12- to 13-month-old American infants and their caregivers using the LENA system. Three 5-minute sections having high child vocalization rates were identified within each recording and coded by trained researchers. Infant and adult vocalizations were sequenced and defined as contingent if they occurred within 1 s, 2 s, or 5 s of each other. When using 1 s or 2 s definitions of temporal adjacency, infant vocalizations generally predicted subsequent infant-directed adult vocalizations. A reflexive vocalization (i.e. a cry or a laugh) was the strongest predictor. Likewise, within 1–2 s timeframes, infant-directed adult speech generally predicted infant vocalizations with reflexive vocalizations being particularly predictive. Infant vocalizations predicted fewer subsequent other-directed adult vocalizations and were less likely following other-directed adult vocalizations when considering up to 5 s lags. This suggests an understudied communicative role for infants of non-infant-directed adult speech. These results demonstrate the importance of timescale in studying infant-adult interactions, support the communicative significance of reflexive infant vocalizations and other-directed adult speech in addition to more commonly studied vocalization types, and highlight the challenges of determining direction(s) of influence when using only two-event sequences.     

The role of the magnocellular and parvocellular pathways in the attentional blink

The attentional blink refers to the transient impairment in perceiving the 2nd of two targets presented in close temporal proximity in a rapid serial visual presentation (RSVP) stream. The purpose of this study was to examine the effect on human attentional-blink performance of disrupting the function of the magnocellular pathway--a major visual-processing pathway specialized in temporal segregation. The study was motivated by recent theories that relate the attentional blink to the limited temporal resolution of attentional responses, and by a number of poorly understood empirical findings, including the effects on the attentional blink of luminance adaptation and distraction. The attentional blink was assessed for stimuli on a red background (Experiment 1), stimuli on an equiluminant background (Experiment 2), and following flicker or motion adaptation (Experiment 3), three psychophysical manipulations known to disrupt magnocellular function. Contrary to our expectations, the attentional blink was not affected by these manipulations, suggesting no specific relationship between the attentional blink and magnocellular and/or parvocellular processing.     

Does attention impair temporal discrimination? Examining non-attentional accounts

Recently, Yeshurun and Levy (Psychol Sci 14:225-231, 2003) have provided evidence for the notion that visual attention impairs the temporal resolution of the visual system. Specifically, the detection of a temporal gap within a visual stimulus was impaired when a cue directed attention towards the spatial location of the stimulus. As this negative cueing effect is important to constrain theories about visual attention, we further investigated this novel effect and assessed whether it truly reflects an attentional effect. Experiment 1 examines whether the negative cueing effect is due to local temporal interference, and Experiments 2 and 3 investigate whether it reflects a luminance confound. The complete pattern of results argues against these alternatives and thus further strengthens the conclusion of Yeshurun and Levy (Psychol Sci 14: 225-231, 2003).     

PTSD青少年对威胁图片注意偏向的时程特点及习惯化倾向

探讨创伤后应激障碍(post-traumatic stress disorder,PTSD)青少年(n=20)与创伤控制组(n=20)对威胁图片注意偏向的时间进程特点以及习惯化倾向.在线索提示任务中,图片的呈现时间为100ms、500ms和1250ms.研究表明:(1)在时间进程上,当图片呈现100ms时,创伤控制组对地震图存在注意警觉;当呈现时间为500ms时,两组被试对负性图和地震图存在注意回避;当呈现时间为1250ms时,PTSD组对负性图仍存在注意回避、对地震图的注意偏向消失,创伤控制组对负性图和地震图的注意偏向均消失.(2)在习惯化倾向上,当第六次呈现威胁图片时,PTSD组对负性图和地震图的注意偏向消失,而创伤控制组对负性图和地震图的注意回避仍未消失.     

On emotional innumeracy: Predicted and actual affective responses to grand-scale tragedies

The present research demonstrates that people overestimate the intensity of their emotional responses to grand-scale tragedies. Participants predicted that they would feel significantly worse if thousands of people were killed in a disaster than if only a few people were killed, and yet they exhibited an “emotional flatline,” feeling equally sad regardless of the number of people killed. This unforeseeable emotional flatline was demonstrated in response to deaths stemming from human violence and natural disasters, both close to home and far away (including hurricanes in the United States, a forest fire in Spain, and the Iraq War). Participants’ actual emotional responses were calibrated with fatalities only when abstract death tolls were translated into concrete images. We argue that affective forecasts and emotional experiences may arise from separate systems, leading to reliable forecasting errors, as well as influencing subsequent judgments.     

The mechanism underlying inhibition of saccadic return

Human observers take longer to re-direct gaze to a previously fixated location. Although there has been some exploration of the characteristics of inhibition of saccadic return (ISR), the exact mechanisms by which ISR operates are currently unknown. In the framework of accumulation models of response times, in which evidence is integrated over time to a response threshold, ISR could reflect a reduction in the rate of accumulation for saccades to return locations or an increase in the effective criterion for response. In two experiments, participants generated sequences of three saccades, in response to a peripheral or a central cue. ISR occurred across these manipulations: saccade latency was consistently increased for movements to the immediately previously fixated location. Latency distributions from individual observers were fit with a Linear Ballistic Accumulator model. ISR was best accounted for as a change in the accumulation rate. We suggest this parameter represents the overall desirability of a particular course of action, the evidence for which may be derived from a variety of sensory and non-sensory sources.