Retention interval and intertrial interval in a serial learning or delayed discrimination task

In each of four experiments, rats were provided with the same three-event decreasing series (18-1-0) of 0.045-g food pellets in a runway. Tracking, running fast to 18 pellets and running slow to 1 and 0 pellets, was investigated as a function of the temporal interval elapsing between the events of the series (the retention interval), shifts in retention interval, and number of trials each day (or the intertrial interval), a trial being defined as presentation of each of the three events of the series. Neither retention interval, which varied from 15 s to 30 min in various investigations, nor shifts in retention interval affected tracking when only one trial was given each day. But when more than one daily trial was given, tracking was acquired more slowly and was disrupted by a shift in retention interval from 15 s to 5 min. Tracking was also disrupted by a shift from one to two trials each day. These results indicate that when given one 18-1-0 trial each day, the rat partitions events on a first-event/subsequent-event basis; that little forgetting occurs even at long retention intervals; that somewhat different memories signal events when one or more than one 18-1-0 trial occurs each day; and that retention interval deficits can arise owing to the same or similar memories' signaling different events. The results described limit the generality of three hypotheses suggested in two recent investigations: that as retention interval increases, rats find it increasingly difficult to remember and utilize serial position cues; that tracking in serial tasks is not influenced by number of trials each day; and that there are specific stimuli associated with each retention interval which, when changed, necessarily disrupt performance.     

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.     

The lengthening effect in sequential estimations of a short interval

Summary Experiments were carried out on the lengthening effect in sequential time estimations. It appeared that lengthening only occurred in the case of intuitive evaluation of an interval. Autocorrelation functions revealed that the estimation process may be described as a series of compensatory actions with respect to the last trial. It was assumed that the last estimate is more or less always experienced as too long or too short. In the resulting correction process the positive corrections reach higher mean values than the negative ones since the upper limit of the interval is not defined. In view of the negative autocorrelation in the last trial it was postulated that the correction process is not random, but is related to sequential response bias, i.e. too many alternations. Subsequently, several presentation and estimation modes were compared. The possibility that lengthening might result from trace decay of the standard stored in memory was doubtful since the phenomenon was also observed in the case of pure production on the basis of verbal instructions only. Apparently, it makes no difference whether a standard is presented or not. The distribution of the time estimates under various conditions revealed that the subject becomes more uncertain in proportion as the amount of external reference given increases, so that estimation process variables seem to be of greater importance than stimulus factors (standard presentation). It was assumed that the temporal memory could be described as a register in which only one event (the last) remains available and forms the subject's frame of reference. Since lengthening appeared to be connected with several cognitive variables of a general nature it was postulated that the effect is not only inherent in time estimation, but may be considered as a phenomenon occurring in repeated estimations of various stimuli as well. This assumption appeared to be correct, as analogous effects were observed in the case of repeated line drawing. It was shown that the increase of the time estimates could be influenced significantly by introducing different risk levels, i.e. the degree of lengthening is a function of the subject's decision criterion. Furthermore, there was some correlation between the compensatory actions and sequential response bias in a randomization task. It is concluded that the lengthening effect does not only show a general character, but that it might be described and explained adequately within the framework of the cognitive theory of time experience in which memory mechanisms, decision theory, and sequential response bias play a significant role.     

“One-thousand<Emphasis Type="Italic">one</Emphasis> … one-thousand<Emphasis Type="Italic">two</Emphasis> …”: Chronometric counting violates the scalar property in interval timing

Medical College of Wisconsin, Milwaukee, Wisconsin Weber’s law applied to interval timing is called thescalar property. A hallmark of timing in the secondsto-minutes range, the scalar property is characterized by proportionality between the standard deviation of a response distribution and the duration being timed. In this temporal reproduction study, we assessed whether the scalar property was upheld when participants chronometrically counted three visually presented durations (8, 16, and 24 sec) as compared with explicitly timing durations without counting. Accuracy for timing and accuracy for counting were similar. However, whereas timing variability showed the scalar property, counting variability did not. Counting variability across intervals was accurately modeled by summing a random variable representing an individual count. A second experiment replicated the first and demonstrated that task differences were not due to presentation order or practice effects. The distinct psychophysical properties of counting and timing behaviors argue for greater attention to participant strategies in timing studies.     

Standard errors and confidence intervals for correlations corrected for indirect range restriction: A simulation study comparing analytic and bootstrap methods

A frequent topic of psychological research is the estimation of the correlation between two variables from a sample that underwent a selection process based on a third variable. Due to indirect range restriction, the sample correlation is a biased estimator of the population correlation, and a correction formula is used. In the past, bootstrap standard error and confidence intervals for the corrected correlations were examined with normal data. The present study proposes a large-sample estimate (an analytic method) for the standard error, and a corresponding confidence interval for the corrected correlation. Monte Carlo simulation studies involving both normal and non-normal data were conducted to examine the empirical performance of the bootstrap and analytic methods. Results indicated that with both normal and non-normal data, the bootstrap standard error and confidence interval were generally accurate across simulation conditions (restricted sample size, selection ratio, and population correlations) and outperformed estimates of the analytic method. However, with certain combinations of distribution type and model conditions, the analytic method has an advantage, offering reasonable estimates of the standard error and confidence interval without resorting to the bootstrap procedure's computer-intensive approach. We provide SAS code for the simulation studies.     

Tempo sensitivity in isochronous tone sequences: the multiple-look model revisited

Factors affecting tempo sensitivity in isochronous tone sequences were investigated in two experiments. Participants listened to tones in sequence conditions in which the number of time intervals in isochronous standard and comparison sequences was varied, and they were asked to judge the tempo of the comparison relative to the standard. When the duration of the standard interval was held constant, tempo sensitivity was affected by the number of comparison intervals, but not by the number of standard intervals. In contrast, when the duration of the standard interval was varied randomly from trial to trial, tempo sensitivity was affected by the number of intervals in both sequences. The present findings are discussed in the context of a generalized multiple-look model that posits independent contributions of both sequences to tempo sensitivity. Quantitative model fits suggest that the relative contribution of the number of the standard intervals to tempo thresholds depends on (1) the availability of a stable long-term referent for the standard tempo and (2) a priori knowledge about the number of standard intervals.     

Rhesus monkeys (Macaca mulatta) enumerate large and small sequentially presented sets of items using analog numerical representations

Two rhesus monkeys selected the larger of two sequentially presented sets of items on a computer monitor. In Experiment 1, performance was related to the ratio of set sizes, and the monkeys discriminated between sets with up to 10 items. Performance was not disrupted when 1 set had fewer than 4 items and 1 set had more than 4 items, a critical trial type for differentiating object file and analog models of numerical representation. Experiment 2 controlled the interitem rate of presentation. Experiment 3 included some trials on which number and amount (visual surface area) offered conflicting cues. Experiment 4 varied the total duration of set presentation and the duration of item visibility. In all of the experiments, performance remained high, although total set presentation duration also acted as a partial cue for the monkeys. Overall, the data indicated that rhesus monkeys estimate the approximate number of items in sequentially presented sets and that they are not relying solely on nonnumerical cues such as rate, duration, or cumulative amount.     

基于概化理论的方差分量变异量估计

概化理论广泛应用于心理与教育测量实践中, 方差分量估计是进行概化理论分析的关键。方差分量估计受限于抽样, 需要对其变异量进行探讨。采用蒙特卡洛(Monte Carlo)数据模拟技术, 在正态分布下讨论不同方法对基于概化理论的方差分量变异量估计的影响。结果表明: Jackknife方法在方差分量变异量估计上不足取; 不采取Bootstrap方法的“分而治之”策略, 从总体上看, Traditional方法和有先验信息的MCMC方法在标准误及置信区间这两个变异量估计上优势明显。     

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).     

Immediate and delayed recognition of sequentially presented random shapes.

Two experiments tested whether short-term memory accounts for the recency effect observed with rapid sequential presentation of nonverbal stimuli. Four random shapes were presented sequentially (with no interstimulus interval) on each trial at rates of 150 msec, 250 msec, 500 msec, and 1,000 msec per stimulus. Subsequent recognition varied positively with exposure duration, ranging from 57% at 150 msec to 77% at 1,000 msec. Two serial position effects were observed: a slight decrease in recognition accuracy for the first stimulus in each sequence and a large increase in recognition for the last stimulus in each sequence. The recency effect was not altered by an intervening 30-sec delay, an intervening 30-sec copying task, or an intervening 30-sec copying and counting task. Since neither visual nor verbal distractors altered recognition accuracy, it was suggested that all shapes were processed directly into long-term memory storage. It also was hypothesized that long-term storage of a nonverbal stimulus requires identification of a distinctive feature of the stimulus and that this process may continue for a brief period after actual stimulus offset.     

Memory in reading and listening to discourse

After reading or listening to short passages, Ss attempted to recognize semantically changed sentences and paraphrases (syntactically and lexically changed sentences). The intervals between the original presentation and test ranged from 1 to 23 sec. In general, paraphrases were poorly detected after a brief time, supporting earlier findings that the exact wording of sentences is not stored in long-term memory. An exception was the high recognition of active-passive changes with the visual presentation. Recognition at the first test interval was significantly better after listening than after reading, although the eventual level of recognition memory was not different in the two modes. This result, consistent with other studies of modality effects in short-term memory, suggests that acoustic-phonetic memory played a role in the storage of the auditorally presented material.     

Recognition memory retention interval and information load

Two experiments were conducted to study the effect of retention interval and information load on short-term recognition memory in retarded subjects. The task consisted of an input trial of 1–15 pictures followed by a test trial of one picture, with the subject having to press different levers to indicate whether the probe picture had been present on the input trial. Retention intervals between input trial and test trial were manipulated over a range of 1–24 sec. Both accuracy and latency of response were measured. Results showed that latency increased and accuracy decreased as a function of both retention interval and number of stimuli. In addition, number of stimuli interacted with retention interval such that accuracy was not affected by retention interval when information input was small, but decreased quite dramatically at longer retention intervals when input was larger. The results were discussed in terms of current memory search models for both normal and retarded subjects.     

Immediate reproduction of temporal information under four cognitive strategies

The main purpose was to determine the retention characteristics of temporal information when subjects experienced time under a retention interval of immediate reproduction and various cognitive strategies for time estimation. Four levels of cognitive strategy were used, viz., conscious, mental counting, counting aloud without auditory cues, and counting aloud with auditory cues. The latter three cognitive strategies were experimenter-defined, time-aiding techniques. Subjects were instructed to refrain from employing time-aiding techniques under a conscious cognitive strategy for time estimation. Visual durations of 1, 2, and 4 sec. were estimated by 12 subjects under the method of reproduction. Two measures of performance were computed, viz., variable and constant errors. The general conclusions were: (a) the effectiveness of mental counting, counting aloud without auditory cues, and counting aloud with auditory cues as cognitive strategies over conscious cognitive strategy in terms of variability depends on the duration used, and (b) in terms of accuracy and variability an increase in the number of cues under time-aiding techniques does not necessarily produce better performance.     

Point-biserial correlation: Interval estimation,hypothesis testing,meta-analysis,and sample size determination

The point-biserial correlation is a commonly used measure of effect size in two-group designs. New estimators of point-biserial correlation are derived from different forms of a standardized mean difference. Point-biserial correlations are defined for designs with either fixed or random group sample sizes and can accommodate unequal variances. Confidence intervals and standard errors for the point-biserial correlation estimators are derived from the sampling distributions for pooled-variance and separate-variance versions of a standardized mean difference. The proposed point-biserial confidence intervals can be used to conduct directional two-sided tests, equivalence tests, directional non-equivalence tests, and non-inferiority tests. A confidence interval for an average point-biserial correlation in meta-analysis applications performs substantially better than the currently used methods. Sample size formulas for estimating a point-biserial correlation with desired precision and testing a point-biserial correlation with desired power are proposed. R functions are provided that can be used to compute the proposed confidence intervals and sample size formulas.     

Inhibitory interaction: the effects of multiple non-predictive visual cues

When the interval between a non-predictive cue and a target appearing at the same spatial location is longer than about 200 ms, target performance is typically poorer than when the cue and target appear at different locations. Recent studies have shown that this effect, known as inhibition of return (IOR), can occur at multiple cued locations, and is enhanced when multiple cues are presented at the same spatial location. However, little is known about how the magnitude of IOR at one spatial location is influenced by a subsequent or preceding cue presented at a different spatial location. We investigated this issue by presenting single or multiple cues at varying inter-cue intervals prior to target onset. Results suggest that the magnitude of IOR at a given location is influenced by the presentation of a preceding cue, but that once IOR occurs, it is unaffected by the presentation of a subsequent cue.     

Rehearsal strategy as a function of recall expectation

The subjects were divided into three groups with respect to their expectations concerning a recall task given after the final trial of the usual STM distractor procedure. Group 1 were told only that they would have to recall during each trial's recall interval, thus did not expect to have to recall again. Group 2 were told that they would have to recall all the words presented in the experiment at the end of the last trial, in addition to the trial-by-trial recall. Group 3 were told only that they would have to recall after all words had been presented and they sat passively through the presentation trials. In addition to their recall expectations, half of the subjects in each group received a 2-s presentation and half received a 5-s presentation interval. It was found that the length of the presentation interval had an effect on the number of words recalled at the end of all trials, but recall expectancy did not. However, expectancy did determine the rehearsal strategies of subjects and hence the serial positions from which items were recalled.     

Stored representations of three-dimensional objects in the absence of two-dimensional cues

Object recognition was studied in human subjects to determine whether the storage of the visual objects was in a two-dimensional or a three-dimensional representation. Novel motion-based and disparity-based stimuli were generated in which three-dimensional and two-dimensional form cues could be manipulated independently. Subjects were required to generate internal representations from motion stimuli that lacked explicit two-dimensional cues. These stored internal representations were then matched against internal three-dimensional representations constructed from disparity stimuli. These new stimuli were used to confirm prior studies that indicated the primacy of two-dimensional cues for view-based object storage. However, under tightly controlled conditions for which only three-dimensional cues were available, human subjects were also able to match an internal representation derived from motion of that of disparity. This last finding suggests that there is an internal storage of an object's representations in three dimensions, a tenet that has been rejected by view-based theories. Thus, any complete theory of object recognition that is based on primate vision must incorporate three-dimensional stored representations.     

Attention effects during visual short-term memory maintenance: protection or prioritization?

Interactions between visual attention and visual short-term memory (VSTM) play a central role in cognitive processing. For example, attention can assist in selectively encoding items into visual memory. Attention appears to be able to influence items already stored in visual memory, as well; cues that appear long after the presentation of an array of objects can affect memory for those objects (Griffin & Nobre, 2003). In five experiments, we distinguished two possible mechanisms for the effects of cues on items currently stored in VSTM. A protection account proposes that attention protects the cued item from becoming degraded during the retention interval. By contrast, aprioritization account suggests that attention increases a cued item's priority during the comparison process that occurs when memory is tested. The results of the experiments were consistent with the first of these possibilities, suggesting that attention can serve to protect VSTM representations while they are being maintained.     

认知诊断属性分类一致性信度区间估计三种方法

摘要：引入了三种可以估计认知诊断属性分类一致性信度置信区间的方法：Bootstrap法、平行测验法和平行测验配对法。用模拟研究验证和比较了这三种方法的表现,结果发现,平行测验法和Bootstrap法在被试量比较少、题目数量比较少的情况下,估计的标准误和置信区间较接近,但是随着被试量的增加,Bootstrap法的估计精度提高较快,在被试量大和题目数量较多时基本接近平行测验配对法的结果。Bootstrap法的所需时间最少,平行测验配对法计算过程复杂且用时较长,推荐用Bootstrap法估计认知诊断属性分类一致性信度的置信区间。     

Using traffic light information as navigational cues: implications for navigation system design

There are compelling research findings that using landmarks such as traffic lights as navigation cues can enhance the acceptability, usability and safety of vehicle navigation systems. In this study, 30 participants undertook an on-road trial using simulated navigation instructions that omitted any reference to distance-to-turn, and instead incorporated information requiring drivers to count traffic lights and pedestrian lights. The study results confirmed that traffic lights can be used as navigation cues even when the density of traffic lights along a stretch of road is high and that the term “set of traffic lights” results in slightly better performance than “traffic lights” alone. Factors other than density were found to have an effect on navigation performance. More errors were made if the target turn was at a pedestrian light and if the turn was visually complex or concealed. In the absence of a navigation task, most drivers did not differentiate between traffic and pedestrian lights when counting the occurrences and only experienced difficulty in counting when the number exceeded 4. Implications for the design of future navigation systems are highlighted.