A demonstration of direct access to colored stimuli following cueing by color

To test whether cueing by color can affect orienting without first computing the location of the cued color, the impact of reorienting on the validity effect was examined. In Experiment 1 subjects were asked to detect a black dot target presented at random on either of two colored forms. The forms started being presented 750 ms before the onset of a central cue (either an arrow or a colored square). In some proportion of the trials the colors switched locations 150 ms after cue onset, simultaneously with target onset. The color switch was not found to retard responses following a color cue more than following a location cue. Furthermore, it did not reduce the validity effect of the color cue: Though the validity effect of the location cue was quite larger than the validity effect of the color cue, both effects were additive with the presence/absence of a color switch. In Experiment 2, subjects were rather asked to detect a change in shape of one of the colored forms. In this case, color switch was found to affect performance even less following a color cue. The fact that across experiments, color switch did not retard neither responding nor orienting selectively in the color cue condition, indicates that when attention is set to a certain color, reorienting to a new object following color switch does not require re-computing the address of the cued color. That finding is argued to embarrass a strong space-based view of visual attention.     

Target-flanker discriminability affects conflict size but not sustained suppression

On successive trials, repetitions of irrelevant information often tend to reduce congruency effects as compared to alternations of irrelevant information. The preferred explanation for this congruency modulation is the sustained-suppression hypothesis, suggesting that suppression of the irrelevant information on a given trial perseveres into the subsequent trial. However, in contrast to the generality of this idea, this modulation is only stable when the irrelevant information contains spatial features, which coincided in the existing research with large conflict sizes and response conflicts. In two arrow flanker experiments, we investigated whether the congruency modulation depends on the size of the conflict, by manipulating the saliency of the target (Experiment 1) and the flankers (Experiment 2). Although these manipulations affected the size of the conflict caused by the flankers, neither experiment showed an influence of conflict size on the reduction of the congruency effect for repetitions as compared to alternation of the irrelevant flankers. We conclude that sustained-suppression is not a consequence of large conflicts, at least if sustained-suppression causes the congruency modulation.     

Target-directed visual attention is a prerequisite for action-specific perception

Witt et al. (2008) have recently shown that golfers who putt with more success perceive the hole to be bigger than golfers who putt with less success. In three experiments, we systematically examined whether this phenomenon, labelled action-specific perception, depends on directing visual attention towards the action target. In Experiment 1 we replicated previously reported action-specific effects on perception in golf putting. In 3 and 4 we directly assessed whether action-specific effects on perception in golf putting are dependent on focusing visual attention on the target. To this end, the participants performed the putting task while visual attention towards the target was either completely withheld (Experiment 2) or divided over the target and other task-relevant objects (Experiment 3). No action-specific effects were found when visual attention towards the action target was occluded or partially diverted from the target. Together, our results provide evidence to suggest that focusing visual attention on the target while performing the action is a prerequisite for the emergence of action-specific perception.     

The relationship between attentional capture and deviations in movement trajectories in a selective reaching task

According to action-centered models of attention, attention and action systems are tightly linked such that the capture of attention by an object automatically initiates response-producing processes. In support of this link, studies have shown that movements deviate towards or away from non-target stimuli. These deviations are thought to emerge because attentional capture by non-target stimuli generates responses that summate with target responses to develop a combined movement vector. The present study tested attention–action coupling by examining movement trajectories in the presence of non-target stimuli that do or do not capture attention. Previous research has revealed that non-target cue stimuli only capture attention when they share critical features with the target. Cues that do not share this feature do not capture attention. Following these studies and their findings, participants in the present study aimed to the location of a single white square (onset singleton target) or a single red square presented with two white squares (color singleton target). In separate blocks, targets were preceded by non-predictive cues that did or did not share the target feature (color or onset singleton cues). The critical finding of the present study was that trajectory effects mirrored the temporal interference effects in that deviations were only observed when cue and target properties matched. Deviations were not observed when the cue and target properties did not match. These data provide clear support for the link between attentional capture and the activation of response-producing processes.     

Mental scanning of sonifications reveals flexible encoding of nonspeech sounds and a universal per-item scanning cost

A mental scanning paradigm was used to examine the representation of nonspeech sounds in working memory. Participants encoded sonifications – nonspeech auditory representations of quantitative data – as either verbal lists, visuospatial images, or auditory images. The number of tones and overall frequency changes in the sonifications were also manipulated to allow for different hypothesized patterns of reaction times across encoding strategies. Mental scanning times revealed different patterns of reaction times across encoding strategies, despite the fact that all internal representations were constructed from the same nonspeech sound stimuli. Scanning times for the verbal encoding strategy increased linearly as the number of items in the verbal representation increased. Scanning times for the visuospatial encoding strategy were generally slower and increased as the metric distance (derived metaphorically from frequency change) in the mental image increased. Scanning times for the auditory imagery strategy were faster and closest to the veridical durations of the original stimuli. Interestingly, the number of items traversed in scanning a representation significantly affected scanning times across all encoding strategies. Results suggested that nonspeech sounds can be flexibly represented, and that a universal per-item scanning cost persisted across encoding strategies. Implications for cognitive theory, the mental scanning paradigm, and practical applications are discussed.     

Retroactive interference in short-term memory and the word-length effect

Two experiments investigated the possibility that the word-length effect in short-term memory (STM) is a consequence of long words generating a greater level of retroactive interference than shorter words. In Experiment 1, six-word lists were auditorily presented under articulatory suppression for immediate serial reconstruction of only the first three words. These three words were always drawn from a single set of middle-length words, whereas the last three positions were occupied by either short or long interfering words. The results showed worse memory performance when the to-be-remembered words were followed by long words. In Experiment 2, a recent-probes task was used, in which recent negative probes matched a target word in trial n-2. The results showed lower levels of proactive interference when trial n-1 involved long words instead of short words, suggesting that long words displaced previous STM content to a greater extent. By two different experimental approaches, therefore, this study shows that long words produce more retroactive interference than short words, supporting an interference-based account for the word-length effect.     

Synchronization in repetitive smooth movement requires perceptible events

Accurate timing performance during auditory–motor synchronization has been well documented for finger tapping tasks. It is believed that information pertaining to an event in movement production aids in detecting and correcting for errors between movement cycle completion and the metronome tone. Tasks with minimal event-related information exhibit more variable synchronization and less rapid error correction. Recent work from our laboratory has indicated that a task purportedly lacking an event structure (circle drawing) did not exhibit accurate synchronization or error correction (Studenka & Zelaznik, in press). In the present paper we report on two experiments examining synchronization in tapping and circle drawing tasks. In Experiment 1, error correction processes of an event-timed tapping timing task and an emergently timed circle drawing timing task were examined. Rapid and complete error correction was seen for the tapping, but not for the circle drawing task. In Experiment 2, a perceptual event was added to delineate a cycle in circle drawing, and the perceptual event of table contact was removed from the tapping task. The inclusion of an event produced a marked improvement in synchronization error correction for circle drawing, and the removal of tactile feedback (taking away an event) slightly reduced the error correction response of tapping. Furthermore, the task kinematics of circle drawing remained smooth providing evidence that event structure can be kinematic or perceptual in nature. Thus, synchronization and error correction, characteristic of event timing (Ivry, Spencer, Zelaznik, & Diedrichsen, 2002; Repp, 2005), depends upon the presence of a distinguishable source of sensory information at the timing goal.     

Extending end-state comfort effect: do we consider the beginning state comfort of another?

Sharing a drink or passing a tool to another person is frequently done in our daily lives. However, a second thought is rarely given about how the object should be handed; instead we pay attention to other factors (e.g., the company). This interaction (handing a tool to someone) is interesting, since it may give insight to how motor intentions are predicted. Research has demonstrated that individuals exhibit an end-state comfort effect when manipulating objects, and it is of interest to determine how this is applied to a joint-action paradigm. The purpose of this experiment was to determine if participants would anticipate the confederate's postural requirements and pass tools in a manner that allowed the confederate to have beginning state comfort and thus facilitate the motion sequence as a whole. That is, would the participant incur the cost of the movement by adopting an awkward posture to facilitate the use of the tool by the confederate? The results demonstrated that participants allowed the confederate to adopt a comfortable beginning state comfort on 100% of the trials for all the tools. However, the participants did not sacrifice end-state comfort, demonstrating that the participants were able to plan ahead to both maximize their own end-state comfort and the beginning state comfort of the confederate.     

卡通面孔分类与识别加工的ERP比较研究

通过ERP方法,考察卡通面孔分类（人和动物）的脑机制及其与卡通面孔识别（人与车）的差异。结果表明,分类任务中,动物面孔VPP潜伏期显著长于人,N170潜伏期主效应不显著、波幅半球效应显著,LPP波幅在顶叶和中央区最大;分类任务VPP和LPP波幅均显著大于识别。结论：卡通面孔分类比识别速度慢、强度大,消耗心理资源多。顶叶和中央区可能是执行分类任务的主要脑区,且加工人类面孔具有优势。面孔加工中结构编码和特征编码可能部分是并行的。     

变长CD-CAT中的曝光控制与终止规则

本研究借鉴传统计算机化自适应测验的思想, 并结合认知诊断的特点, 在认知诊断框架下提出了4种变长CD-CAT的终止规则, 分别是属性标准误法(SEA)、邻近后验概率之差法(DAPP)、二等分法(HA)以及混合法(HM)。在未控制曝光和采用不同曝光控制条件下, 与HSU法及KL法进行了比较。研究结果表明：(1) 终止条件越严格, 平均测验长度越长, 按测验长度最大值终止的测验百分比越大, 模式判准率越高。(2) 当未加入曝光控制时, 4种新的终止规则均有较好表现, 与HSU法十分接近。随着最大后验概率预设值的增加或e的减小, 模式判准率呈上升趋势, 平均测验长度逐渐增加, 但在题库使用率方面均较差。(3) 当加入项目曝光控制时, 6种变长终止规则下的题库使用率有了极大的提升, 仍能保持较高的模式判准率, 并且不同的曝光控制方法对终止规则的影响是不同的。其中, 相对标准终止规则极易受到曝光控制方法的影响。(4) 综合来看, SEA、HM以及HA法在各项指标上的表现与HSU法基本一致, 其次为KL法和DAPP法。