Speech perception by budgerigars(Melopsittacus undulatus): The voiced-voiceless distinction

Discrimination of synthetic speech sounds from the bilabial, alveolar,and velar voice onset time (VOT) series was studied in 5 budgerigars. The birds were trained, using operant conditioning procedures, to detect changes in a repeating background of sound consisting of a synthetic speech token. Response latencies for detection were measured and were used to construct similarity matrices. Multidimensional scaling procedures were then used to produce spatial maps of these speech sounds, in which perceptual similarity was represented by spatial proximity. The results of these experiments suggest that budgerigars discriminate among synthetic speech sounds from these three VOT continua, especially between those from the bilabial and alveolar series, in a categorical fashion.     

Role of selective attention in artificial grammar learning

To investigate the role of selective attention in artificial grammar (AG) learning, participants were presented with “GLOCAL” strings—that is, chains of compound global and local letters. The global and local levels instantiated different grammars. The results of this experiment revealed that participants learned only the grammar for the level to which they attended. The participants were not even able to choose presented but unattended strings themselves. These results show that selective attention plays a critical role in AG learning.     

Learning from others’ mistakes in capuchin monkeys (<Emphasis Type="Italic">Cebus apella</Emphasis>)

We investigated whether tufted capuchin monkeys (Cebus apella) learn from others' mistakes. We prepared three kinds of transparent containers having the same appearance: one that could be opened by the lid, one that could be opened from the bottom, and one that could be opened either way. Using each of the first two one-way-open type containers, the monkeys were trained to copy the human demonstrator's action to open the container and obtain a piece of sweet potato contained therein. After this training, the demonstrator showed the monkeys an action that would open or fail to open the third, two-way-open type container. None of the monkeys reliably opened the container by spontaneously compensating for the demonstrator's failure (Experiment 1). In Experiment 2, the same subjects were trained to correct their own mistakes immediately after failure, before we introduced the same test as in Experiment 1. This experience did not result in subjects using the demonstrator's failure to produce a successful action. In Experiment 3, we placed two monkeys face to face. In this situation, the second monkey was presented with the container after the first monkey failed to open it. As a result, two capuchin monkeys capitalized on the partner's failure to correctly guide his/her behavior. Thus, the monkeys monitored not only the outcome of the others' action, but also that action per se. This result suggests that not only humans and apes, but also monkeys may understand the meaning of others' actions in social learning.     

A paper-format group performance test for measuring the implicit association of target concepts

We developed a paper test utilizing a mechanism for measuring implicit association similar to that used in the Implicit Association Test (IAT; Greenwald, McGhee, & Schwartz, 1998). The target concepts were buried among positive and negative words on a piece of paper. Examinees marked the targets as "bad" or "good" in one task and conversely in the other, along with the evaluative words. Instead of reaction times, we counted the number of words marked in 20 sec for each task. This procedure allowed group administration. We calculated the implicit measure using the difference in the average number of words marked in the task pairs. The results of a test administered to 82 undergraduates with three different targets showed significant correlations (rs = .26-.35) with the results of IAT administered to the same participants. It also showed significant reliability (rs = .56-.71). We discuss the practical usability of the test with application studies conducted in various areas.     

A New Concurrent Calibration Method for Nonequivalent Group Design under Nonrandom Assignment

This study proposes a new item parameter linking method for the common-item nonequivalent groups design in item response theory (IRT). Previous studies assumed that examinees are randomly assigned to either test form. However, examinees can frequently select their own test forms and tests often differ according to examinees’ abilities. In such cases, concurrent calibration or multiple group IRT modeling without modeling test form selection behavior can yield severely biased results. We proposed a model wherein test form selection behavior depends on test scores and used a Monte Carlo expectation maximization (MCEM) algorithm. This method provided adequate estimates of testing parameters.     

Metamemory in tufted capuchin monkeys (Cebus apella)

Whereas evidence for metacognition by nonhuman primates has been obtained in great apes and old world monkeys, it is weaker in new world monkeys. For instance, capuchin monkeys may fail to recognize their own knowledge of the location of invisible bait. In the present study, we tested whether tufted capuchin monkeys would flexibly change their behavior in a delayed matching-to-sample (DMTS) test depending upon the strength of their memory trace of the sample. In Experiment 1, two monkeys were tested on a modified 9-alternative DMTS task with various delays on a computerized display. In some trials, the monkeys could choose whether to go for a memory test or for a simple key touch as an escape from the test. In other trials, they were forced to go for the memory test. Both monkeys escaped from the memory test more often when their matching accuracy on forced tests was lower. In one of the monkeys, the matching accuracies on chosen memory tests decreased more slowly as a function of delay length, and were higher after long delays than those on forced memory tests. This suggests that at least one capuchin monkey was able to recognize the strength of his own memory trace. Experiment 2 employed occasional no-sample tests, in which the monkeys faced the task choice without presentation of any sample for the trial. The monkey who was successful in Experiment 1 declined the memory test more often in no-sample trials than regular trials, further indicating metamemory in this individual. In Experiment 3, this successful monkey received a task, in which he was sometimes able to choose between shape MTS or texture MTS tasks. However, his matching accuracies did not differ between chosen tasks and forced tasks. Thus, the metamemory possessed by this new world monkey species may be more like a flag, showing strength of memory trace, than an elaborate representation showing details of the memory trace.     

Evidence for the efficacy of the MORI technique: Viewers do not notice or implicitly remember details from the alternate movie version

The MORI technique provides a unique way to research social influences on memory. The technique allows people to watch different movies on the same screen at the same time without realizing that each of them sees something different. As a result, researchers can create a situation in which people feel as though they share an experience, but systematic differences are introduced into their memories, and the effect of those differences can be tracked through a discussion. Despite its methodological advances, the MORI technique has been met with criticism, mostly because reviewers are worried that the MORI technique might not completely block the alternate movie version from view, leading people in these studies to see their partner’s version of the movie as well as their own. We addressed these concerns in two experiments. We found no evidence that subjects noticed the alternate movie version while watching a movie via the MORI technique (Experiment 1) and no evidence that subjects remembered details from the alternate movie version (Experiment 2). Taken together, the results provide support for the MORI technique as a valuable research tool.     

Observational learning in capuchin monkeys: a video deficit effect

Young human children have been shown to learn less effectively from video or televised images than from real-life demonstrations. Although nonhuman primates respond to and can learn from video images, there is a lack of direct comparisons of task acquisition from video and live demonstrations. To address this gap in knowledge, we presented capuchin monkeys with video clips of a human demonstrator explicitly hiding food under one of two containers. The clips were presented at normal, faster than normal, or slower than normal speed, and then the monkeys were allowed to choose between the real containers. Even after 55 sessions and hundreds of video demonstration trials the monkeys’ performances indicated no mastery of the task, and there was no effect of video speed. When given live demonstrations of the hiding act, the monkeys’ performances were vastly improved. Upon subsequent return to video demonstrations, performances declined to pre-live-demonstration levels, but this time with evidence for an advantage of fast video demonstrations. Demonstration action speed may be one aspect of images that influence nonhuman primates’ ability to learn from video images, an ability that in monkeys, as in young children, appears limited compared to learning from live models.     

An empirical examination of the mechanisms mediating between high-performance work systems and the performance of Japanese organizations

The resource-based view of the firm and social exchange perspectives are invoked to hypothesize linkages among high-performance work systems, collective human capital, the degree of social exchange in an establishment, and establishment performance. The authors argue that high-performance work systems generate a high level of collective human capital and encourage a high degree of social exchange within an organization, and that these are positively related to the organization's overall performance. On the basis of a sample of Japanese establishments, the results provide support for the existence of these mediating mechanisms through which high-performance work systems affect overall establishment performance.     

The effect of exogenous spatial attention on auditory information processing

This study investigated the effect of exogenous spatial attention on auditory information processing. In Experiments 1, 2 and 3, temporal order judgment tasks were performed to examine the effect. In Experiment 1 and 2, a cue tone was presented to either the left or right ear, followed by sequential presentation of two target tones. The subjects judged the order of presentation of the target tones. The results showed that subjects heard both tones simultaneously when the target tone, which was presented on the same side as the cue tone, was presented after the target tone on the opposite side. This indicates that spatial exogenous attention was aroused by the cue tone, and facilitated subsequent auditory information processing. Experiment 3 examined whether both cue position and frequency influence the resulting information processing. The same effect of spatial attention was observed, but the effect of attention to a certain frequency was only partially observed. In Experiment 4, a tone fusion judgment task was performed to examine whether the effect of spatial attention occurred in the initial stages of hearing. The result suggests that the effect occurred in the later stages of hearing.