重复启动对时序知觉和时距知觉的影响

采用时序判断和时距估计任务,探讨重复启动对时序知觉和时距知觉的影响。结果表明：在时序判断中,当未启动的靶刺激先出现时出现了显著的启动效应,启动的靶刺激被知觉为早出现;在启动的靶刺激先出现时产生了启动效应的反转,启动的靶刺激被知觉为后出现。在时距估计中,启动条件下的两个靶刺激之间的时距长度被知觉为显著长于未启动条件下的时距长度。因此,在同一时间历程中,重复启动对时序知觉和时距估计都存在显著影响,启动刺激所引发的表征激活和反应抑制双加工过程在时序知觉中是按照表征匹配机制、在时距知觉中是基于唤醒机制起作用,这为时间认知分段综合模型的理论构想提供了支持证据。     

Somatosensory prior entry assessed with temporal order judgments and simultaneity judgments

Attention is central to perception, yet a clear understanding of how attention influences the latency of perception has proven surprisingly elusive. Recent research has indicated that spatially attended stimuli are perceived earlier than unattended stimuli across a range of sensory modalities-an effect termed prior entry. However, the method commonly used to measure this, the temporal order judgment (TOJ) task, has been criticized as susceptible to response bias, despite deliberate attempts to minimize such bias. A preferred alternative is the simultaneity judgment (SJ) task. We tested the prior-entry hypothesis for somatosensory stimuli using both a TOJ task (replicating an earlier experiment) and an SJ task. Prior-entry effects were found for both, though the effect was reduced in the SJ task. Additional experiments (TOJ and SJ) using visual cues established that the earlier perception of cued tactile targets does not result from intramodal sensory interactions between tactile cues and targets.     

判断框架对时序知觉位置启动效应的影响

研究采用包含两种判断框架（判断刺激出现的先后次序）的时序判断任务探讨了决策偏向对时序知觉位置启动效应的影响。实验结果表明,时序知觉中存在着位置启动效应,而且在两个靶刺激出现时间间隔不同时,被试在“哪个靶刺激先出现”和“哪个靶刺激后出现”两种判断框架下的正确率存在显著差异,但在两个靶刺激同时出现时并没有出现显著的判断框架效应。因此,本研究推测时序知觉位置启动效应的作用机制不仅包括知觉增强加工过程,而且也与认知决策有关,这为反应偏向理论提供了新的支持证据。     

Localisation of auditory targets during optokinetic nystagmus

Previous studies have shown that the perceived location of visual stimuli briefly flashed during smooth pursuit, saccades, or optokinetic nystagmus (OKN) is not veridical. We investigated whether these mislocalisations can also be observed for brief auditory stimuli presented during OKN. Experiments were carried out in a lightproof sound-attenuated chamber. Participants performed eye movements elicited by visual stimuli. An auditory target (white noise) was presented for 5 ms. Our data clearly indicate that auditory targets are mislocalised during reflexive eye movements. OKN induces a shift of perceived location in the direction of the slow eye movement and is modulated in the temporal vicinity of the fast phase. The mislocalisation is stronger for look- as compared to stare-nystagmus. The size and temporal pattern of the observed mislocalisation are different from that found for visual targets. This suggests that different neural mechanisms are at play to integrate oculomotor signals and information on the spatial location of visual as well as auditory stimuli.     

Implicit learning increases preference for predictive visual display

We investigated whether implicit learning in a visual search task would influence preferences for visual stimuli. Participants performed a contextual cueing task in which they searched for visual targets, the locations of which were either predicted or not predicted by the positioning of distractors. The speed with which participants located the targets increased across trials more rapidly for predictive displays than for non-predictive displays, consistent with contextual cueing. Participants were subsequently asked to rate the "goodness" of visual displays. The rating results showed that they preferred predictive displays to both non-predictive and novel displays. The participants did not recognize predictive displays any more frequently than they did non-predictive or novel displays. These results suggest that contextual cueing occurred implicitly and that the implicit learning of visual layouts promotes a preference for visual layouts that are predictive of target location.     

Temporal resolution of figures and grounds

Recent studies have demonstrated that establishing figure–ground organization influences other perceptual processes. Specifically, figures undergo perceptual processing earlier than ground regions (Lester, Hecht, & Vecera, 2009), and they are processed for longer durations relative to ground regions (Hecht & Vecera, 2011). One potential consequence of figures' extended processing is degraded temporal resolution compared to ground regions. To test this hypothesis, observers completed a modified flicker-fusion task while viewing either displays that contained well-defined figures and grounds or displays that were ambiguous. As evidenced by increased sensitivity for flickering targets on the ground regions, the current results support the claim that figures have poorer temporal resolution than ground regions.     

Unconscious processing of color and form in metacontrast masking

Three experiments employed a metacontrast masking procedure to examine the extent and nature of priming effects from visual stimuli not consciously perceived. The results showed effects of unconscious stimuli on subsequent target responses that (1) were more consistent, reliable, and not subject to strategic control, as compared with consciously perceived stimuli (Experiment 1); (2) produced both facilitation and interference of subsequent processing (Experiment 2); and (3) did not influence indirect response-related levels of processing (Experiment 3). These results demonstrate that color and form attributes of unconscious stimuli are sufficiently registered within the visual system to influence behavior, and that some of these unconscious effects occur at early levels of stimulus encoding, prior to higher level perceptual and response-related processes.     

Emotional distraction unbalances visual processing

Brain mechanisms used to control nonemotional aspects of cognition may be distinct from those regulating responses to emotional stimuli, with activity of the latter being detrimental to the former. Previous studies have shown that suppression of irrelevant emotional stimuli produces a largely right-lateralized pattern of frontal brain activation, thus predicting that emotional stimuli may invoke temporary, lateralized costs to performance on nonemotional cognitive tasks. To test this, we briefly (85 ms) presented a central, irrelevant, expressive (angry, happy, sad, or fearful) or neutral face 100 ms prior to a letter search task. The presentation of emotional versus neutral faces slowed subsequent search for targets appearing in the left, but not the right, hemifield, supporting the notion of a right-lateralized, emotional response mechanism that competes for control with nonemotional cognitive processes. Presentation of neutral, scrambled, or inverted neutral faces produced no such laterality effects on visual search response times.     

A tachistoscopic study of hemispheric processing in stuttering and nonstuttering children

Hemispheric processing, expressed as mean reaction time to various visual stimuli presented to the left and right visual fields, was investigated in eighteen stuttering and nonstuttering children. Tachistoscopic procedures were used to present linguistic stimuli (words and nonwords) as well as nonlinguistic stimuli (familiar and unfamiliar geometric figures) to the visual fields. Subjects responded by pressing a telegraph key when they perceived a real word or a familiar geometric figure. They were to make no response when they perceived nonwords or unfamiliar geometric figures. Faster reaction times were taken as an index of the most efficient or dominant hemisphere for a given task. No significant differences were found in mean reaction times for groups, visual fields, type of task, nor any of their interactions. Likewise, the data on accuracy also did not suggest that a larger proportion of stutters responded more accurately when linguistic stimuli were presented to the right hemisphere. Based on mean reaction times and on accuracy data, the stuttering and nonstuttering children performed with similar efficiencies and processing patterns.     

Somatosensory prior entry

The perceived timing of sensory events does not necessarily match the actual timing. In the present study, we investigated the effect of location of attention on the perceived timing of somatosensory stimuli. Participants judged the temporal order of two taps, delivered one to each hand, with taps presented at different elevations (upper and lower) on the opposing hands. The task was to discriminate the elevation of the tap presented first (or second). This vertical discrimination task was orthogonal to the horizontal attentional cuing manipulation, removing the response bias confound that has undermined earlier studies investigating the impact of attention on the perceived timing of sensory stimuli. We manipulated spatial attention either (1) exogenously (Experiment 1) in 13 participants, using brief taps to either the left or right hand, or (2) endogenously (Experiment 2) in 22 participants, using centrally presented symbolic cues. The results supported the hypothesis that attended stimuli are perceived more rapidly than unattended stimuli. This effect was larger when attention was exogenously manipulated. Previous research has demonstrated a similar effect for visual stimuli. The present study, which extends this result to somatosensory perception, indicates that the phenomenon may represent a more global feature of the perceptual system, which is possibly mediated by a common modality-independent mechanism.     

‘A good odour to breathe?’ The effect of pleasant ambient odour on human visual vigilance

The present study examined the effect of an alerting and a relaxing odour on human visual vigilance. Three groups of undergraduates (N = 54) completed a sustained visual vigilance task which required them to respond whenever a target stimulus appeared on a computer monitor. One group completed the task in the presence of an alerting odour (peppermint), another did so in the presence of a relaxing odour (bergamot) and a third group completed the task in an unscented environment. A 2×3×2 (sex×odour×diurnal preference) MANOVA was performed in order to determine group differences in response times and number of correct detections. Participants in the bergamot condition detected fewer targets correctly within 1.25 seconds of the target appearing than did those in the peppermint or no‐odour groups. Exposure to bergamot was also associated with significantly fewer correct detections in the second than in the first half of the task, when compared with the other two conditions. The results suggest that sustained exposure to a relaxing odour can impair visual vigilance. Copyright © 2001 John Wiley & Sons, Ltd.     

Cognitive-behavioral and electrophysiological evidence of the affective consequences of ignoring stimulus representations in working memory

Ignoring visual stimuli in the external environment leads to decreased liking of those items, a phenomenon attributed to the affective consequences of attentional inhibition. Here we investigated the generality of this “distractor devaluation” phenomenon by asking whether ignoring stimuli represented internally within visual working memory has the same affective consequences. In two experiments we presented participants with two or three visual stimuli and then, after the stimuli were no longer visible, provided an attentional cue indicating which item in memory was the target they would have to later recall, and which were task-irrelevant distractors. Participants subsequently judged how much they liked these stimuli. Previously-ignored distractors were consistently rated less favorably than targets, replicating prior findings of distractor devaluation. To gain converging evidence, in Experiment 2, we also examined the electrophysiological processes associated with devaluation by measuring individual differences in attention (N2pc) and working memory (CDA) event-related potentials following the attention cue. Larger amplitude of an N2pc-like component was associated with greater devaluation, suggesting that individuals displaying more effective selection of memory targets—an act aided by distractor inhibition—displayed greater levels of distractor devaluation. Individuals showing a larger post-cue CDA amplitude (but not pre-cue CDA amplitude) also showed greater distractor devaluation, supporting prior evidence that visual working-memory resources have a functional role in effecting devaluation. Together, these findings demonstrate that ignoring working-memory representations has affective consequences, and adds to the growing evidence that the contribution of selective-attention mechanisms to a wide range of human thoughts and behaviors leads to devaluation.     

Suppression history of distractor location biases attentional and oculomotor control

Past selection experience greatly affects the deployment of attention such that targets are more readily selected if their features or locations were more frequently selected in the past. Crucially, recent studies have shown similar experience-dependent effects also for salient task irrelevant stimuli: distractors exerted less interference if they appeared at a location where they were presented more often, relatively to other possible locations. Here we investigated the effects of such suppression history on the immediate behavioural correlates of attentional deployment, i.e., eye movements. Participants were to make saccadic eye movements to a target stimulus, while ignoring a highly distracting irrelevant visual onset appearing abruptly on the screen in a proportion of trials. Crucially, this irrelevant onset occurred more frequently in two locations on the visual display and our results showed that, relatively to distractors elsewhere, onsets presented at these locations became easier to ignore, giving rise to reduced oculomotor capture. Consistent with the notion that experience can alter attentional deployment towards spatial locations, these findings indicate that, through learning, the priority of high frequency locations becomes suppressed, attenuating the intrinsic saliency of distractors appearing therein. Traces left by individual events of attentional suppression decrease the processing priority of coordinates within topographic maps of the visual space.     

Attentional Capture by Emotional Stimuli: Manipulation of Emotional Valence by the Sample Pre‐rating Method

Eye movements directed at emotional and neutral pictures were investigated. Participants were instructed to fixate on a target and avoid looking at a non‐target. Results of trials consisting of emotional and neutral pictures were analyzed based on participants’ evaluations of the stimuli before the experiment. Results indicated that the number and duration of fixations were larger and longer for targets than for non‐targets. Further, the probability of first fixation was less for neutral targets than for emotional targets. This suggests that unpleasant pictures capture visual attention and that the attentional orienting is subject to automatic response. The possibility that top‐down processes of visual attention may be involved in attentional capture was also discussed.     

Effects of spatial cues on locating emotional targets

Inhibition of return (IOR) refers to slower responding to a visual target appearing at a previously cued versus uncued location. In three experiments, we asked whether IOR would be affected by the emotional content of target stimuli. Participants reported the location of negative (spiders, angry faces) or neutral (objects, neutral faces) targets as quickly and accurately as possible after a valid or invalid location cue (a simple circle). IOR was significantly smaller when detecting negative versus neutral targets, but only after repeated exposures to these stimuli (i.e., with blocked presentations). This effect was eliminated when target type was randomized within blocks. By presenting negative versus neutral targets in short alternating blocks and examining IOR on the first trial of each new block, we show that the emotional modulation of IOR stems from the affective context in place before visual orienting is initiated, not by perceptual processing of the target after cue offset.     

Interference in eyewitness and earwitness recognition

Face identification and voice identification were examined using a standard old/new recognition task in order to see whether seeing and hearing the target interfered with subsequent recognition. Participants studied either visual or audiovisual stimuli prior to a face recognition test, and studied either audio or audiovisual stimuli prior to a voice recognition test. Analysis of recognition performance revealed a greater ability to recognise faces than voices. More importantly, faces accompanying voices at study interfered with subsequent voice identification but voices accompanying faces at study did not interfere with subsequent face identification. These results are similar to those obtained in previous research using a lineup methodology, and are discussed with respect to the interference that can result when earwitnesses are also eyewitnesses. Copyright © 2010 John Wiley & Sons, Ltd.     

Goal-driven attentional capture by invisible colors: Evidence from event-related potentials

We combined event-related brain potentials (ERPs) and behavioral measures to test whether subliminal visual stimuli can capture attention in a goal-dependent manner. Participants searched for visual targets defined by a specific color. Search displays served as metacontrast masks for preceding cue displays that contained one cue in the target color. Although this target-color cue was spatially uninformative, it produced behavioral spatial cuing effects and triggered an ERP correlate of attentional selection (i.e., the N2pc component). These results demonstrate that target-color cues captured attention, in spite of the fact that cue localization performance assessed in separate blocks was at chance level. We conclude that task-set contingent attentional capture is not restricted to supraliminal stimuli, but is also elicited by visual events that are not consciously perceived.     

Retrieval dynamics in self-terminated memory search

Attended stimuli are perceived as occurring earlier than unattended stimuli. This phenomenon of prior entry is usually identified by a shift in the point of subjective simultaneity (PSS) in temporal order judgements (TOJs). According to its traditional psychophysical interpretation, the PSS coincides with the perception of simultaneity. This assumption is, however, questionable. Technically, the PSS represents the temporal interval between two stimuli at which the two alternative TOJs are equally likely. Thus it also seems possible that observers perceive not simultaneity, but uncertainty of temporal order. This possibility is supported by prior-entry studies, which find that perception of simultaneity is not very likely at the PSS. The present study tested the percept at the PSS in prior entry, using peripheral cues to orient attention. We found that manipulating attention caused varying temporal perceptions around the PSS. On some occasions observers perceived the two stimuli as simultaneous, but on others they were simply uncertain about the order in which they had been presented. This finding contradicts the implicit assumption of most models of temporal order perception, that perception of simultaneity inevitably results if temporal order cannot be discriminated.     

Directed attention prolongs the perceived duration of a brief stimulus

Stelmach, Herdman, and McNeil (1994) suggested recently that the perceived duration for attended stimuli is shorter than that for unattended ones. In contrast, the attenuation hypothesis (Thomas & Weaver, 1975) suggests the reverse relation between directed attention and perceived duration. We conducted six experiments to test the validity of the two contradictory hypotheses. In all the experiments, attention was directed to one of two possible stimulus sources. Experiments 1 and 2 employed stimulus durations from 70 to 270 msec. A stimulus appeared in either the visual or the auditory modality. Stimuli in the attended modality were rated as longer than stimuli in the unattended modality. Experiment 3 replicated this finding using a different psychophysical procedure. Experiments 4-6 showed that the finding applies not only to stimuli from different sensory modalities but also to stimuli appearing at different locations within the visual field. The results of all six experiments support the assumption that directed attention prolongs the perceived duration of a stimulus.     

Time,change, and motion: The effects of stimulus movement on temporal perception

The effects of stimulus motion on time perception were examined in five experiments. Subjects judged the durations (6–18 sec) of a series of computer-generated visual displays comprised of varying numbers of simple geometrical forms. In Experiment 1, subjects reproduced the duration of displays consisting of stationary or moving (at 20 cm/sec) stimulus figures. In Experiment 2, subjects reproduced the durations of stimuli that were either stationary, moving slowly (at 10 cm/sec), or moving fast (at 30 cm/sec). In Experiment 3, subjects used the production method to generate specified durations for stationary, slow, and fast displays. In Experiments 4 and 5, subjects reproduced the duration of stimuli that moved at speeds ranging from 0 to 45 cm/sec. Each experiment showed that stimulus motion lengthened perceived time. In general, faster speeds lengthened perceived time to a greater degree than slower speeds. Varying the number of stimuli appearing in the displays had only limited effects on time judgments. Other findings indicated that shorter intervals tended to be overestimated and longer intervals underestimated (Vierordt’s law), an effect which applied to both stationary and moving stimuli. The results support a change model of perceived time, which maintains that intervals associated with more changes are perceived to be longer than intervals with fewer changes.