时距的短时保持: 缩短还是变长

采用Wearden和Ferrara(1993)的经典方法, 分别考察了1s以下(350 ms~650 ms)和1s以上(1000 ms ~ 2000 ms)不同类型(空、实时距)和通道(视、听)时距的短时保持效应。实验1发现, 不同刺激通道条件下, 1s以下时距的短时保持都呈现出主观缩短, 其中视觉条件比听觉条件明显; 实验2表明, 1s以上时距在不同刺激通道条件下都呈现出主观变长, 其中听觉条件比视觉条件明显。分析表明, 主观缩短趋势可能是由主观缩短效应和正的顺序误差效应共同作用所致, 而主观变长趋势是由主观变长效应和负的顺序误差效应造成的。     

时间信息视听通道效应的实验检验

研究从时点类型、自然顺序标码、延迟时间等几个角度,对时间信息时序和时距属性的通道效应进行了实验检验。结果发现,（1）长时距信息估计仍存在通道效应;（2）延迟时间估计增加了视觉时距估计的准确性;（3）时序信息通道效应不明显;（4）顺序标码有利于听觉的时间信息加工。     

数目及其呈现方式在不同范围内对时间知觉的影响

采用时间比较法,考察数目及其呈现方式对时间知觉的影响。任务中,首先呈现标准时距,此时变化刺激的数目或呈现方式,然后呈现比较时距,被试的任务是判断比较时距比标准时距长还是短。实验1和实验2分别采用1秒内和1秒以上的时间,结果发现： 1秒内的时间加工中,刺激一个一个连续呈现时,小数引起标准时距的低估,大数导致标准时距的高估,而同时呈现时,刺激的数目对知觉到的时间无影响;数目及其呈现方式影响计时的准确性,而对计时的变异性和敏感性无影响。时间在1秒以上,同时呈现和连续呈现条件下,刺激的数目影响知觉到的时间;计时的     

工作记忆的存储时间及目标时距对时间知觉的影响

本研究操作记忆信息与计时开始之间的时间间隔（ISI）和目标时距,探讨工作记忆影响时间判断的灵活性。被试首先记忆一个客体,然后在每个trial的最后判断测试刺激是否与记忆项相同;在延迟阶段,被试完成时间判断任务,即判断相继出现的两个刺激的时距哪个更长（或更短）。时间任务中的一个刺激与记忆内容完全相同,相应的另一个刺激与记忆内容在形状和颜色上都不同。重复条件下,被试忽略第一个刺激,仅完成时间判断任务。结果发现,时间间隔（ISI）短时,记忆匹配条件下的准确率更高,匹配刺激延长了知觉的时间;但随着时间间隔的增加,工作记忆匹配对时间判断的影响降低甚至消失。并且,长或短ISI,记忆任务或重复条件下,目标时距长时,记忆匹配反而缩短了知觉的时间。研究说明工作记忆对时间判断的影响是灵活的,受到注意或工作记忆等高级认知系统的调控。     

短时距估计中刺激物的动态变化效应

用两个实验考查了时距估计中刺激物的动态变化效应。结果发现,刺激物的运动、速度和旋转角度显著地影响着被试的时间判断,刺激物速度的时距延长效应对于较长时距(18s-24s)来说更加明显;运动刺激与较短、较准确的时距判断相关联;旋转角度的减少使得被试低估时距,而旋转角度的增加使得时距估计呈高估倾向。被试在时间估计过程中表现出长时距低估和短时距高估现象,本研究得到的时间估计转换点是11.4s,此点与先前的有关研究基本一致。     

1～6秒时距认知分段性特征

时距认知分段性指不同长度时距的加工机制和表征方式是不同的。以往研究者对1 s以上时距认知的分段性仍存在分歧,为了探讨这一主题,本研究设计了实验1和实验2。实验1采用时间复制任务比较高、低工作记忆容量被试在完成1~6 s视、听时距加工的成绩,结果发现,时距长度与工作记忆容量或通道均存在交互作用,被试在复制1 s、2 s的平均复制时距、复制比率及变异系数没有随工作记忆容量或通道而变化,而复制3 s、4 s、5 s及6 s时,高WMC组较低WMC组或听觉组较视觉组,平均复制时距显著更长、复制比率显著更高、变异系数显著更小。实验2采用时间产生任务比较高、低工作记忆容量被试在完成1~6 s视、听时距加工的成绩,结果也发现,时距长度与工作记忆容量或通道均存在交互作用,被试在产生1 s、2 s的平均产生时距、产生比率及变异系数没有随工作记忆容量或通道而变化,而产生3 s、4 s、5 s及6 s时,高WMC组较低WMC组或听觉组较视觉组,平均产生时距显著更短、产生比率显著更低、变异系数显著更小。这意味着1~6 s的时距认知存在分段性,大约2~3 s可能为分段临界点。时间认知的分段性可以用时间工作记忆说解释,该假说是时间认知分段综合模型解释短时距加工分段性的具体表现形式。     

回溯式时距估计的动态性及心理机制

时间流逝过程中, 回溯式时距估计动态性体现在短时延迟和长时发展两个方面。前者聚焦秒、分级的延迟, 将其归为背景变化或由目标时距引发的认知差异; 后者聚焦跨年龄(如婴儿、儿童到成年)的个体发展, 认为主要是信息加工速度的差异。最后, 从综合视角出发, 认为其动态性可能是由不同时距信息心理表征的差异造成的, 这体现时间认知的分段综合性。未来需以时间流逝的动态视角开展回溯式时距估计的心理表征研究, 深入探讨与目标时距紧密相关的计时策略在回溯式时距估计中的作用, 并扩展年龄、人格类型等个体差异方面的动态特征研究。     

时间记忆层次网络模型的实验检验

实验采用分类性实验材料,使被试在对词单项目加工时形成较清晰的群集,进而形成时间组块,目的在于对时间记忆层次网络进行直接检验。其中时序判断用反时间时和正确率两种反应指标,时距估计用再现和口头估计两种方法。结果发现,时间信息记忆既存在层次网络的特征,又存在线性结构的特征。     

动词的延续性特征及瞬时时间副词对时间转换事件表征的影响

为考察语篇阅读中,汉语动词的延续性特征以及瞬时时间副词对时间转换事件表征的影响,采用探测-判断的语篇实时阅读技术分别进行了两个实验。实验1的结果表明,当描述转换前事件的动词是延续性动词时,短时转换句与瞬时转换句的阅读时间无显著差异;而当描述转换前事件的动词是短暂性动词时,短时转换句的阅读时间明显长于瞬时转换句的阅读时间。实验2的结果表明,当不在时间转换句前添加瞬时时间副词时,长时与短时转换句前探测词的再认时间存在显著差异;而当在时间转换句前添加瞬时时间副词时,长时与短时转换句前探测词的再认时间无显著差异。两个实验结果分别说明,动词的延续性特征和时间转换短句的结合影响了时间转换事件的表征,在长时转换句的前面添加瞬时时间副词缩短了长时转换事件的表征时间。     

视听时间再校准：适应空间与适应客体的联合及独立作用

同一事件的视听成分即使同时发生, 由于两种信息的物理传播与神经传导速度的差异, 大脑知觉到它们的时刻仍会存在一定的延迟。时间再校准指大脑可以最小化并适应这段时间延迟的现象。本研究采用“适应—测验”范式, 在适应阶段连续给被试呈现视觉先于听觉或听觉先于视觉128ms的刺激对, 在测验阶段以时序判断任务来测量被试此时主观同时点的变化。通过操纵适应及新异视听刺激对(即适应客体与新异客体)在测验阶段出现的空间位置, 探索空间与客体因素对视听时间再校准的影响。结果发现, 当适应客体出现于适应空间时, 主观同时点显著偏向了时间延迟的方向; 同样显著或边缘显著的主观同时点偏移还发生于适应客体出现于未适应空间时, 以及新异客体出现于适应空间时。研究表明, 视听时间再校准在不同空间中的表现取决于适应空间与适应客体的联合或独立作用。     

Temporal changes in visual and acoustic codes in a letter-matching task

The objective of the present experiment was to examine the nature of the coding process in a letter-matching task. Letter pairs that were either visually confusable or acoustically confusable or both visually and acoustically confusable were presented tachistoscopically with a variable interval between the first letter and the comparison letter. The dependent measure was RT for the “different” responses to the three types of confusable items which were each assessed at four interstimulus intervals ranging from 0 to 2 sec. The results indicate that a visual code appears to be emphasized for approximately 1 sec, after which an acoustic code seems to be dominant. There is also evidence which indicates that the acoustic code does not immediately replace the visual code and that both may coexist for a brief period of time.     

Accuracy of temporal coding: Auditory-visual comparisons

Three experiments were designed to decide whether temporal information is coded more accurately for intervals defined by auditory events or for those defined by visual events. In the first experiment, the irregular-list technique was used, in which a short list of items was presented, the items all separated by different interstimulus intervals. Following presentation, the subject was given three items from the list, in their correct serial order, and was asked to judge the relative interstimulus intervals. Performance was indistinguishable whether the items were presented auditorily or visually. In the second experiment, two unfilled intervals were defined by three nonverbal signals in either the auditory or the visual modality. After delays of 0, 9, or 18 sec (the latter two filled with distractor activity), the subjects were directed to make a verbal estimate of the length of one of the two intervals, which ranged from 1 to 4 sec and from 10 to 13 sec. Again, performance was not dependent on the modality of the time markers. The results of Experiment 3, which was procedurally similar to Experiment 2 but with filled rather than empty intervals, showed significant modality differences in one measure only. Within the range of intervals employed in the present study, our results provide, at best, only modest support for theories that predict more accurate temporal coding in memory for auditory, rather than visual, stimulus presentation.     

A temporal parameter influencing choice between signalled and unsignalled shock schedules

The present study investigated whether choice of a signalled variable-time shock schedule over an unsignalled one was influenced by the average intershock interval. Eight rats were given a choice between signalled and unsignalled shock schedules in a series of conditions with average intershock intervals of 510, 270, 150, 90, 60, and 45 sec. Each test condition was preceded by a training-baseline condition, and schedule values were arranged in an ascending (four subjects) or descending (four subjects) order. Choice of the signalled conditions was directly related to the average intershock interval of the variable-time schedule for six of the eight subjects. The per cent of time in the signalled condition was highest when the average intershock interval was 150 sec or longer and lowest when the average intershock interval was 45 sec. The findings were interpreted as being due to changes in the safety features of the signalled schedule, rather than to changes in the average intershock interval per se.     

Temporal structure of letter groups and span of perception

The span of perception for letter groups depends on number of letters presented, length of presentation and structure of the groups. The experiment reported varied the temporal structure of the groups, leaving the total number of letters constant. Groups of 12 letters were presented as a whole or in two or more successive “units.” The total time of presentation was 1-5 sec. In the first experiment each unit was visible until the next appeared, in the second experiment units were visible only during 1/4 sec., although intervals between successive units were kept constant.

The following conclusions emerged:

(a) The visual presence of units did not affect the reproduction for durations over 0.25 sec., except in the 12-letter presentations.

(b) 2×6 letters gave better results than either simultaneous presentation or other divisions; temporal separation was 0.75 sec.

(c) Higher order approximations to Dutch have more influence on 3 × 4, 2 × 6 and 1 × 12 letters than on 4 × 3 and 6 × 2 letters.

(d) A serial order effect exists: central units are reproduced less well than first and last units.

It is suggested that handling a fixed amount of information within a fixed period is limited on the one hand by confusion between simultaneous elements and on the other hand by the interaction between successive units presented too rapidly to allow for proper operation of immediate memory.

The difference between span of perception and span of memory is stressed.     

Temporal and interactional effects in short-term storage

The operation of temporal and interactional processes in short-term storage was studied under conditions which require that information about all items presented be stored and the relative retention of all be evaluated concurrently, but preclude further interference after presentation by testing or retrieval effects. Random sequences of twelve two digit numbers from a known set of thirteen were presented visually at 1, 2, or 4 per sec. for full interval and .25 sec. presentation durations to 15 Ss who reported the missing number that was not presented from the set. For 1/sec. full duration presentations the missing scan serial position error distribution shows a linear decrease in errors from first through last presented items. As rate of presentation increases there is a linear increase in total errors, a linearly increasing primacy effect, and an increase of errors over at least the last half of the sequence such that the error distribution remains linear with the same slope. These findings are compatible with the operation of time dependent interactional and perceptual processes in short-term storage but not with autonomous decay.     

Temporal ventriloquism in a purely temporal context

This study examines how audiovisual signals are combined in time for a temporal analogue of the ventriloquist effect in a purely temporal context, that is, no spatial grounding of signals or other spatial facilitation. Observers were presented with two successive intervals, each defined by a 1250-ms tone, and indicated in which interval a brief audiovisual stimulus (visual flash + noise burst) occurred later. In "test" intervals, the audiovisual stimulus was presented with a small asynchrony, while in "probe" intervals it was synchronous and presented at various times guided by an adaptive staircase to find the perceived temporal location of the asynchronous stimulus. As in spatial ventriloquism, and consistent with maximum likelihood estimation (MLE), the asynchronous audiovisual signal was shifted toward the more reliably localized component (audition, for all observers). Moreover, these temporal shifts could be forward or backward in time, depending on the asynchrony order, suggesting perceived timing is not entirely determined by physical timing. However, the critical signature of MLE combination--better bimodal than unimodal precision--was not found. Regardless of the underlying model, these results demonstrate temporal ventriloquism in a paradigm that is defined in a purely temporal context.     

Vibro-tactile and visual asynchronies: sensitivity and consistency

We investigated the consistency between tactually and visually designated empty time intervals. In a forced-choice discrimination task, participants judged whether the second of two intervals was shorter or longer than the first interval. Two pulses defined the intervals. The pulse was either a vibro-tactile burst presented to the fingertip, or a foveally presented white square. The comparisons were made for uni-modal and cross-modal intervals. We used four levels of standard interval durations in the range of 100- 800 ms. The results showed that tactile empty intervals must be 8.5% shorter to be perceived as long as visual intervals. This cross-modal bias is larger for small intervals and decreases with increasing standard intervals. The Weber fractions (the threshold divided by the standard interval) are 20% and are constant over the standard intervals. This indicates that the Weber law holds for the range of interval lengths tested. Furthermore, the Weber fractions are consistent over uni-modal and cross-modal comparisons, which indicates that there is no additional noise involved in the cross-modal comparisons.     

The “ventriloquist effect”: Visual dominance or response bias?

The interaction between vision and audition was investigated using a signal detection method. A light and tone were presented either in the same location or in different locations along the horizontal plane, and the subjects responded with same-different judgments of stimulus location. Three modes of stimulus presentation were used: simultaneous presentation of the light and tone, tone first, and light first. For the latter two conditions, the interstimulus interval was either 0.7 or 2.0 sec. A statistical decision model was developed which distinguished between the perceptual and decision processes. The results analyzed within the framework of this model suggested that the apparent interaction between vision and audition is due to shifts in decision criteria rather than perceptual change.     

Two temporal parameters of food postponement

Rats were trained to press a lever under schedules of food postponement. In the absence of lever presses, food was delivered periodically (food-food interval). Responses initiated a second interval (response-food interval) that was reset by each additional response. Performance was first studied at different response-food intervals with the food-food interval fixed at 30 or 60 sec, or 10 min. Response-food intervals were examined in ascending order and then recovery was studied at shorter intervals. Finally, the food-food interval was manipulated with response-food interval fixed at 30 sec. At food-food intervals of 30 and 60 sec, responding first increased and then decreased as the response-food interval increased. At the 10-min food-food interval, responding decreased with increasing response-food interval. In general, very low rates of responding occurred when the response-food interval was 60 sec or more and when it equalled or exceeded the food-food interval. However, responding was maintained in one animal when the food-food interval was decreased from 120 to 15 sec with the response-food interval at 30 sec. Results, in terms of several dependent variables, are compared with data on shock avoidance. Effects of response-independent and response-produced food and shock are discussed.     

Discrimination of time intervals presented in sequences: spatial effects with multiple auditory sources

This article discusses two experiments on the discrimination of time intervals presented in sequences marked by brief auditory signals. Participants had to indicate whether the last interval in a series of three intervals marked by four auditory signals was shorter or longer than the previous intervals. Three base durations were under investigation: 75, 150, and 225 ms. In Experiment 1, sounds were presented through headphones, from a single-speaker in front of the participants or by four equally spaced speakers. In all three presentation modes, the highest different threshold was obtained in the lower base duration condition (75 ms), thus indicating an impairment of temporal processing when sounds are presented too rapidly. The results also indicate the presence, in each presentation mode, of a 'time-shrinking effect' (i.e., with the last interval being perceived as briefer than the preceding ones) at 75 ms, but not at 225 ms. Lastly, using different sound sources to mark time did not significantly impair discrimination. In Experiment 2, three signals were presented from the same source, and the last signal was presented at one of two locations, either close or far. The perceived duration was not influenced by the location of the fourth signal when the participant knew before each trial where the sounds would be delivered. However, when the participant was uncertain as to its location, more space between markers resulted in longer perceived duration, a finding that applies only at 150 and 225 ms. Moreover, the perceived duration was affected by the direction of the sequences (left-right vs. right-left).