The effect of sample and comparison ratio schedules on delayed matching to sample in the pigeon

In Experiment 1, three food-deprived pigeons received trials that began with red or green illumination of the center pecking key. Two or four pecks on this sample key turned it off and initiated a 0- to 10-sec delay. Following the delay, the two outer comparison keys were illuminated, one with red and one with green light. In one condition, a single peck on either of these keys turned the other key off and produced either grain reinforcement (if the comparison that was pecked matched the preceding sample) or the intertrial interval (if it did not match). In other conditions, 3 or 15 additional pecks were required to produce reinforcement or the intertrial interval. The frequency of pecking the matching comparison stimulus (matching accuracy) decreased as the delay increased, increased as the sample ratio was increased, and decreased as the comparison ratio was increased. The results of Experiment 2 suggested that higher comparison ratios adversely affect matching accuracy primarily by delaying reinforcement for choosing the correct comparison. The results of Experiment 3, in which delay of reinforcement for choosing the matching comparison was manipulated, confirmed that delayed reinforcement decreases matching accuracy.     

Transfer of oddity learning in the pigeon

Two pigeons were trained on a six-key modified oddity-from-sample procedure. The stimuli were olor pictures of birds, butterflies, and human faces. Initially, the third peck on the sample key which presented one of three different bird pictures) lit only one comparison key. Every three dditional pecks on the sample illuminated another comparison key. Fifteen sample pecks produced he maximum of five comparison stimuli. A peck on the comparison key that presented the non-atching bird picture produced grain. Pecks on matching keys turned off all the comparison keys nd repeated the trial. The birds learned to peck each sample until the non-matching comparison timulus was produced, and then to peck that key. After acquisition (70%–90% accuracy), the hree bird stimuli were replaced by a new set of three bird pictures. Subsequent phases provided ew sets of bird, butterfly, and human face stimuli. Both birds showed transfer of oddity learning o the novel samples. The data suggest that the birds may have been engaging in conceptual-type oddity learning, rather than learning discrete five-key discriminations or a series of two component chains.     

The determiners of keypeck duration

In Experiment 1, pigeons were exposed to a discriminative autoshaping procedure in which one keylight was correlated with negative automaintenance and the other keylight was correlated with positive automaintenance. The negative automaintenance procedure maintained shorter keypeck durations than the positive automaintenance procedure. Keypecking tended to occur in bursts of two, three, or four pecks, and within these bursts keypeck durations reliably decreased. In Experiment 2, keypeck durations and off-keypecks were initially examined during exposure to a positive automaintenance procedure. When a negative keypeck-reinforcer contingency was introduced, keypeck durations decreased and the ratio of off-keypecks to on-keypecks increased. When a positive keypeck-reinforcer contingency was introduced, keypeck durations increased and the ratio of off-keypecks to on-keypecks decreased. These results suggest that keypeck duration is determined by the extent to which the peck is directed at the key.     

Remembering: The role of extraneous reinforcement

In two experiments, pigeons' responding on an extraneous task was explicitly reinforced during delayed matching-to-sample trials. In Experiment 1, red or green sample stimuli were followed by retention intervals of 0.2, 1, 4, or 12 sec, during which pecks to a white center key were reinforced with 2.5-sec access to wheat according to extinction, variable-interval 30-sec, and variable-interval 15-sec schedules in different conditions. A proportion of .2, .5, .7, or .9 of subsequent red or green choice responses that matched the sample were reinforced with 3-sec access to wheat. The result was that increasing center key reinforcement, or reducing reinforcer probability, lowered overall accuracy. Initial discriminability fell, but with no change in the rate of forgetting. In Experiment 2, initial discriminability was affected by extraneous reinforcers that were contingent on center key pecking, but not by noncontingent reinforcers. A plausible conclusion is that initial discriminability decreases when reinforcers strengthen competing behaviors.     

Dissociation of the effect of reinforcer type and response strength on the force of a conditioned response

A dissociation between the effect of reinforcer type and response strength on the force of the pigeon’s keypeck response was shown in three experiments. In Experiment 1, pigeons were trained to peck two conditioned stimuli, one paired with water and another paired with grain. The pigeons made more forceful pecks for grain than for water and also showed a tendency, albeit an unreliable one, to respond on a higher percentage of food trials than water trials. In Experiment 2, the pigeons from Experiment 1 were satiated with either food or water and were then presented with the two conditioned stimuli in an extinction test. It was found that, regardless of the drive state, the pigeons made more forceful pecks to the stimulus that predicted food than to the stimulus that predicted water. In the thirsty group, however, this difference in force was not accompanied by a difference in the percentage of trials with a response. In Experiment 3, pigeons trained with a single reinforcer pecked more often on instrumentally reinforced trials than on Pavlovian conditioning trials, but there was no difference in the force of the pecks. Taken together, these results imply that differences in response strength cannot account for the difference between the force of food- and water-reinforced pecks. Instead, stimulus-substitution theory may provide the best account of the topography of the two types of pecks.     

Grasping in the pigeon (Columba livid): Stimulus control during conditioned and consummatory responses

Control of beak opening (gape) and peck location was examined in pigeons. Feeding pecks showed accurate guidance that positioned the seed between the beaks. At the moment of contact with the seed, gape was proportional to seed diameter, although pecks with gape less than seed diameter were more frequent following an increase in seed size during a meal. There were no substantial differences between pigeons trained to keypeck with autoshaping and those trained with operant conditioning procedures. With either procedure, water reinforcement produced keypecks with the beak closed; seed reinforcers of different sizes produced means for gape proportional to the seed diameters. Black or white circular stimuli of different sizes projected as conditioning signals had little influence upon gape, but a greater percentage of responses was directed to white stimuli. These results indicate that visual stimuli elicit and orient the peck, whereas the adjustment of gape also involves the somatosensory stimuli provided during previous experience with a particular reinforcer or food type.     

Restricted processing of simultaneously presented brightness and pattern stimuli in pigeons

Performance during simultaneous matching-to-sample was assessed in pigeons presented with element and compound visual samples. In Experiment 1, pigeons were trained with a symbolic matching procedure, in which different pairs of colored comparison cues presented on side keys were mapped onto a bright or dim houselight as one pair of sample stimuli and onto vertical and horizontal lines on the center key as a second pair of sample stimuli. They were then tested with houselight-line compound samples. It was found that matching accuracy for lines was significantly diminished with compound samples relative to element samples. Conversely, house-light intensities were matched as well with compound samples as with element samples. In Experiment 2, a similar effect was found with pigeons that had been trained to match only line samples. In Experiment 3, it was discovered that sample duration had no influence on the matching deficit found with lines following compound samples in birds either trained or not trained to match houselight intensities. These results, taken in combination with recent findings from experiments with auditory-visual compounds, suggest a restricted processing account of pigeon processing of simultaneously presented stimuli from different sources.     

Attention shifts during matching-to-sample performance in pigeons

Two pigeons performed a matching-to-sample task in which a color, a line orientation, or both, might appear on the sample. Stimulus control by (attention to) the color and line components of a compound sample was measured when (a) either component might be relevant (i.e., appear as a comparison stimulus on that trial), and (b) when only one component was relevant. Degree of stimulus control by a given component of the compound sample was higher when only it was relevant than when either component might be relevant. Because the matching-to-sample task separated sample inspection from response choice, interpretation of the results in terms of response competition was ruled out. Because the training procedure led to shifts in stimulus control by the components of the compound sample, explanation of previous matching-to-sample results in terms of reduced perceptual clarity of compound samples was also ruled out. Thus, variations in stimulus control by components of the compound sample were interpreted as showing shifts in attention to the components of the compound sample.     

基于BP神经网络的认知诊断评估分类准确率影响因素分析

BP神经网络是目前应用最广泛的人工神经网络模型之一,在分类和识别上表现出良好的特性,因此被研究者用于认知诊断评估以对被试进行诊断分类。通过模拟研究,考查属性个数、属性层级关系、测验长度、题目质量、测试样本量5个因素对BP神经网络在认知诊断中分类准确性的影响。结果表明:1)基于BP神经网络的认知诊断分类准确率不依赖于测试样本量;2)题目质量和测验长度对BP神经网络的诊断准确率有显著的积极影响;3)属性个数对BP神经网络的分类准确率有消极影响;4)题目质量一定程度上会影响BP诊断方法在不同属性层级结构上的分类准确率。     

Spatial matching and nonmatching in male and female Wistar rats: Effects of delay-interval duration

Male and female Wistar rats were trained in a delayed matching-to-position procedure in which one of the two levers (sample) was presented. Pressing this lever resulted in its retraction and began a delay interval of random variable duration, which terminated with the occurrence of the first nose poke in the pellet retrieval unit after the delay interval had expired. Both levers were then inserted into the chamber, and food became available when the subject pressed the lever that had previously been pressed (matching response). When the subject failed to make a matching response, time out (5 sec) was presented. In the next experimental condition, nonmatching was reinforced. Males and females required an equal number of trials to attain 80% accuracy during three consecutive sessions under matching and nonmatching conditions. Response accuracy decreased as the delay interval increased, during both conditions. Differences between the sexes were not observed, suggesting that memory functions in male and female rats may only differ when other behavioral differences between the sexes are allowed to interfere with the assessment of memory functioning.     

基于多属性分类的KNN改进算法

提出了一种基于多属性分类的KNN改进算法,可有效提高传统的欧几里德KNN算法和基于信息熵的KNN改进算法的分类准确度。首先,按照单个属性不同属性值的个数占整个属性包含样本的比例进行属性的分类,分为基于信息熵的KNN算法处理的离散属性和基于传统欧几里德KNN相似度处理的连续属性两类,然后分别对不同属性进行区别处理;其次,将两类不同处理后得到的结果按比例求和作为样本之间的距离;最后,选取与待测样本的距离最小的k个样本判断测试样本的决策属性类别。     

The effects of musical training on the decoding skills of German‐speaking primary school children

This paper outlines the results of a long‐term study of 159 German‐speaking primary school children. The correlations between musical skills (perception and differentiation of rhythmical and tonal/melodic patterns) and decoding skills, and the effects of musical training on word‐level reading abilities were investigated. Cognitive skills and socioeconomic factors were controlled as covariates in all analysis. The experimental group received special musical training for 9 months. A comparison sample received alternative training (visual arts) for the same amount of time. Another comparison sample did not receive any additional classes during the study period. The results show that rhythmical abilities are correlated significantly positively with decoding skills (both reading accuracy and reading prosody). Tonal skills, however, were not correlated with reading skills. Additionally, the special musical training had a significant effect on reading accuracy in word reading, as analysis of covariance revealed. In this paper, implications for reading development are discussed.     

Using the Attribute Hierarchy Method to Make Diagnostic Inferences about Examinees’ Cognitive Skills in Critical Reading

The purpose of this study is to apply the attribute hierarchy method (AHM) to a subset of SAT critical reading items and illustrate how the method can be used to promote cognitive diagnostic inferences. The AHM is a psychometric procedure for classifying examinees’ test item responses into a set of attribute mastery patterns associated with different components from a cognitive model. The study was conducted in two steps. In step 1, three cognitive models were developed by reviewing selected literature in reading comprehension as well as research related to SAT Critical Reading. Then, the cognitive models were validated by having a sample of students think aloud as they solved each item. In step 2, psychometric analyses were conducted on the SAT critical reading cognitive models by evaluating the model‐data fit between the expected and observed response patterns produced from two random samples of 2,000 examinees who wrote the items. The model that provided best data‐model fit was then used to calculate attribute probabilities for 15 examinees to illustrate our diagnostic testing procedure.     

Stimulus salience and asymmetric forgetting in the pigeon

Pigeons were trained using a symbolic delayed matching-to-sample procedure involving bright versus dim houselight samples. We hypothesized that when sample stimuli differ in salience, increasing the size of the retention interval will affect performance on trials initiated by the more salient sample only. In agreement with this prediction, accuracy following the dim sample did not decline as the retention interval increased, whereas accuracy following the bright sample declined to well below 50% correct. In a second experiment, the less salient (dim) sample from Experiment 1 was arranged as the more salient sample in a sample/no-sample procedure. Accuracy on dim sample trials then declined to well below 50% correct as the retention interval increased, whereas accuracy on no-sample trials remained constant. The results suggest that when sample stimuli differ in salience, pigeons may transform the nominal discrimination task into a detection task in which they respond on the basis of the presence or absence of the more salient sample.     

Attribute‐Level and Pattern‐Level Classification Consistency and Accuracy Indices for Cognitive Diagnostic Assessment

Classification consistency and accuracy are viewed as important indicators for evaluating the reliability and validity of classification results in cognitive diagnostic assessment (CDA). Pattern‐level classification consistency and accuracy indices were introduced by Cui, Gierl, and Chang. However, the indices at the attribute level have not yet been constructed. This study puts forward a simple approach to estimating the indices at both the attribute and the pattern level through one single test administration. Detailed elaboration is made on how the upper and lower bounds for the attribute‐level accuracy can be derived from the variance of error of the attribute mastery probability estimate. In addition, based on Cui's pattern‐level indices, an alternative approach to estimating the attribute‐level indices is also proposed. Comparative analysis of simulation results indicate that the new indices are very desirable for evaluating test‐retest consistency and correct classification rate.     

“counting” by pigeons: Discrimination of the number of biologically relevant sequential events

Numerical competence has been studied in animals under a variety of conditions, but only a few experiments have reported animals’ ability to detect absolute number. Capaldi and Miller (1988) tested rats’ ability to detect absolute number by using biologically important events—the number of reinforced runs followed by a nonreinforced run—and found that the rats ran significantly slower on the nonreinforced run. In the present experiments, we used a similar procedure. Pigeons were given a sequence of trials in which responding on the first three trials ended in reinforcement but responding on the fourth trial did not (RRRN). When the response requirement on each trial was a single peck (Experiment 1), we found no significant increase in latency to peck on the fourth trial. When the response requirement was increased to 10 pecks (Experiment 2), however, the time to complete the peck requirement was significantly longer on the nonreinforced trial than on the reinforced trials. Tests for control by time, number of responses, and amount of food consumed indicated that the pigeons were using primarily the number of reinforcements obtained in each sequence as a cue for nonreinforcement. This procedure represents a sensitive and efficient method for studying numerical competence in animals.     

Differential effects of omitting comparison stimuli on symbolic and identity matching to sample: Evidence for altered instructional processes in pigeon short-term memory

Two experiments were performed to determine the effects of omitting the comparison stimuli in a matching-to-sample task. In Experiment 1, birds were trained initially on both symbolic and identity matching to sample. Comparison stimuli were then omitted following the presentation of a particular sample stimulus, and this decreased the number of sample (observing) responses. The reintroduction of the comparison stimuli on subsequent probe trials revealed that the accuracy of symbolic matching was reduced to chance levels, while identity matching accuracy was significantly below chance. In Experiment 2, a similar procedure was employed; however, observing responses to the comparison-omitted samples were maintained by direct reinforcement (fixed ratio 20). Matching accuracy during probe trials was again at chance levels for symbolic matching but, contrary to Experiment 1, was significantly above chance for identity matching. The differential effects of omitting comparison stimuli on symbolic and identity matching trials in these two experiments were interpreted within a framework which assumes that instructional processes are altered by comparison-omission procedures.     

Proving the Usefulness of Demonstrations: Using M&M's to Develop Attribute Control Charts

Experiential‐based mini‐demonstrations are useful to facilitate student learning on a wide variety of topics. The purpose of this teaching brief is two‐fold: (1) it outlines a useful mini‐demonstration to teach attribute control charting when the sample size is unknown, and (2) adds additional proof that experiential methods positively impact upon student learning. The goal of this mini‐demonstration is to assist undergraduate and graduate students to develop their hands‐on statistical quality control charting and quality management concepts. By using this mini‐demonstration in one operations management class and not another, students that participated in this mini‐demonstration performed significantly better (p= .05) than their counterparts in testing. The mini‐demonstration may be extended to include computer integration, used in small or large class sizes, and provides an efficient, effective use of classroom time to develop concepts.     

EMPIRICAL COMPARISON OF SELECTED ITEM BIAS DETECTION PROCEDURES WITH BIAS MANIPULATION

Biased test items were intentionally imbedded within a set of test items, and the resulting instrument was administered to large samples of blacks and whites. Three popular item bias detection procedures were then applied to the data: (1) the three-parameter item characteristic curve procedure, (2) the chi-square method, and (3) the transformed item difficulty approach. The three-parameter item characteristic curve procedure proved most effective at detecting the intentionally biased test items; and the chi-square method was viewed as the best alternative. The transformed item difficulty approach has certain limitations yet represents a practical alternative if sample size, lack of computer facilities, or the like preclude the use of the other two procedures.     

Intuitive statistical inference: Categorization of binomial samples depends on sampling context

Pigeons categorized binomial samples. One of two “coins” was tossed on each trial, and birds learned to infer from observing the outcomes which of the two equally likely coins had been tossed. Outcomes (“heads” or “tails”) appeared as successively presented red or green center keys. Coin R was biased in favor of red, and coin G was similarly biased in favor of green. A categorization consisted of a choice of a left or right side key and was reinforced with food if it was to the key (left for coin R and right for coin G) corresponding to the coin that produced that trial’s sample. Coin bias and minimum sample size required for reinforcement were experimentally manipulated. When sample size was greatest (n=8), categorizing a sample as having been produced by coin R tended to undermatch the probability that the sample was produced by coin R. When sample size was smallest (n=1), categorizing a sample overmatched, provided that the context did not include other trials with large samples. This context effect reconciles an otherwise inconsistent literature on intuitive statistical inference in pigeons but suggests a new and difficult goal for research-the general clarification of the effects of sampling context on inference.