The variability of practice hypothesis in motor learning: does it apply to Alzheimer's disease?

Based on Schmidt's (1975) variability of practice hypothesis, this study examined acquisition and transfer of a gross motor skill, namely tossing, in 58 patients with Alzheimer's disease (AD) and 58 healthy older adults under constant, blocked, and random practice conditions. While healthy older adults were able to learn the tossing task equally well under the three practice conditions, only AD patients receiving constant practice showed significant improvements. Tests of intermediate transfer yielded the expected random practice advantage in healthy controls but not AD patients. None of the practice conditions facilitated intermediate transfer in AD patients; however, constant practice did benefit these impaired individuals on tests of near transfer. These results indicate that the variability of practice hypothesis does not extend to AD patients. As motor learning and transfer were clearly a function of constant practice, future attempts to retrain basic activities of daily living in AD patients should emphasize consistency in training.     

The role of inferences about referential intent in word learning: evidence from autism

Young children are readily able to use known labels to constrain hypotheses about the meanings of new words under conditions of referential ambiguity. At issue is the kind of information children use to constrain such hypotheses. According to one theory, children take into account the speaker's intention when solving a referential puzzle. In the present studies, children with autism were impaired in monitoring referential intent, but were equally successful as normally developing 24-month-old toddlers at mapping novel words to unnamed items under conditions of referential ambiguity. Therefore, constraints that lead the child to map a novel label to a previously unnamed object under these circumstances are not solely based on assessments of speakers' intentions.     

Interfering neighbours: the impact of novel word learning on the identification of visually similar words

We assessed the impact of visual similarity on written word identification by having participants learn new words (e.g. BANARA) that were neighbours of familiar words that previously had no neighbours (e.g. BANANA). Repeated exposure to these new words made it more difficult to semantically categorize the familiar words. There was some evidence of interference following an initial training phase, and clear evidence of interference the following day (without any additional training); interference was larger still following more training on the second day. These findings lend support to models of reading that include lexical competition as a key process.     

Individual Accountability in Cooperative Learning Groups at the College Level: Differential Effects on High,Average, and Low Exam Performers

Over a three-semester period in a large undergraduate human development course, students were assigned to 5–7 member groups to work together in preparing for an exam in one of the five content units in the course. Their exam performance was tracked over three units: a baseline unit in which students worked only individually, a unit in which they worked in cooperative teams, and a follow-up unit in which the formal cooperative team structure was removed. Three different bonus-credit contingencies were used in the cooperative learning unit across the three semesters: (a) awarding full bonus credit to each individual in the group if the group as a whole improved its exam performance by the specified amount, (b) awarding partial bonus credit to each individual in the group if the group as a whole improved it exam performance by the specified amount and full bonus credit to each individual who also improved by the specified amount, and (c) awarding full bonus credit to an individual in the group if both the group and the individual improved exam performance by the specified amount. The three contingencies produced somewhat similar patterns of change for low and average performers, but the high performers fared better under the last two contingencies than under the group-only contingency.     

Working Memory and Learning in Early Alzheimer’s Disease

Cognitive deficits associated with early Alzheimers disease (AD) have been recently operationalised in terms of an acquisition deficit and the research supporting this view is presented. However, there is still debate concerning the nature of this deficit and how underlying cognitive processes may be detrimentally affecting the ability to acquire new information in early AD. This review argues that the pattern of cognitive deficits contributing to the acquisition impairment in early AD patients may be readily interpreted within the context of a working memory model. Isolating the component processes of working memory that underlie the acquisition deficit in early AD patients will aid in the design of clinical applications that are focussed at enhancing the ability to acquire new information in everyday life.     

Academic Self-Schemas and their Self-Congruent Learning Patterns: Findings Verified with Culturally Different Samples

This paper reported two studies investigating high school students’ academic self-schemas in learning mathematics and their self-congruent learning engagement patterns. Using cluster analyses, Study 1 located two contrasting groups of students holding positive and negative self-schemas in learning mathematics among Chinese participants. MANOVA analyses showed that these two groups of Chinese schematic students differed from each other in the use of achievement goals, approaches to learning, and expected levels of performance. These findings were validated and extended in Study 2 using a culturally different sample, Australian students. Again, cluster analyses successfully classified Australian participants into positive and negative schematic clusters. It was also found that these two groups of schematic students approached learning mathematics in a self-congruent manner similar to those found in Study 1. The converging results in both studies lent empirical support to the theoretical formulation of positive and negative schematic students and the validity of using the self-schema concept to investigate motivation and learning. The differences in their learning engagement patterns were discussed in terms of students’ different academic self-schemas in learning mathematics.     

Bottlenose dolphin (Tursiops truncatus) calves appear to model their signature whistles on the signature whistles of community members

Bottlenose dolphins are unusual among non-human mammals in their ability to learn new sounds. This study investigates the importance of vocal learning in the development of dolphin signature whistles and the influence of social interactions on that process. We used focal animal behavioral follows to observe six calves in Sarasota Bay, Fla., recording their social associations during their first summer, and their signature whistles during their second. The signature whistles of five calves were determined. Using dynamic time warping (DTW) of frequency contours, the calves signature whistles were compared to the signature whistles of several sets of dolphins: their own associates, the other calves associates, Tampa Bay dolphins, and captive dolphins. Whistles were considered similar if their DTW similarity score was greater than those of 95% of the whistle comparisons. Association was defined primarily in terms of time within 50 m of the mother/calf pair. On average, there were six dolphins with signature whistles similar to the signature whistles of each of the calves. These were significantly more likely to be Sarasota Bay resident dolphins than non-Sarasota dolphins, and (though not significantly) more likely to be dolphins that were within 50 m of the mother and calf less than 5% of the time. These results suggest that calves may model their signature whistles on the signature whistles of members of their community, possibly community members with whom they associate only rarely.     

Tool-use learning in Tonkean macaques (Macaca tonkeana)

The transmission of tool use is a rare event in monkeys. Such an event arose in a group of semi-free-ranging Tonkean macaques (Macaca tonkeana) in which leaning a pole against the parks fence (branch leaning) appeared and spread to several males. This prompted us to test individual and social learning of this behavior in seven young males. In the first experiment, three males learned individually to obtain a food reward using a wooden pole as a climbing tool. They began using the pole to retrieve the reward only when they could alternatively experience acting on the object and reaching the target. In a second experiment, we first tested whether four other subjects could learn branch leaning after having observed a group-mate performing the task. Despite repeated opportunities to observe the demonstrator, they did not learn to use the pole as a tool. Hence we exposed the latter subjects to individual learning trials and they succeeded in the task. Tool use was not transmitted in the experimental situation, which contrasts with observations in the park. We can conclude that the subjects were not able to recognize the target as such. It is possible that they recognized it and learned the task individually when we alternated the opportunity to act upon the object and to reach the reward. This suggests that these macaques could then have associated the action they exercised upon the pole and the use of the pole as a means to reach the reward.     

Successive reversal of concurrent discriminations by macaques (Macaca mulatta): proactive interference effects

Rhesus monkeys received concurrent within-session training on eight, two-choice object pairs and then underwent successive reversals of these problems. Initially, reversals required about six times more training than acquisition with no improvement over seven successive reversals. Surprisingly, performance on these eight problems was unimpaired if they were embedded in different eight-problem tasks, thereby indicating a release from proactive interference. When the original eight problems again underwent successive reversal, no improvement was seen over seven reversals, although there was significantly less error-per-reversal than in the initial test. Subsequently, monkeys appeared to be developing a learning set for successive reversal because performance on successive reversal of eight novel problems was not different from that seen with the old familiar task. Set acquisition was confirmed when proficient reversal was eventually achieved on both old and new concurrent tasks. Thus, concurrent reversal set did develop, but it required arduous training to overcome proactive interference effects on memory. The ubiquitous influence of measurement context on organization of monkey memory was noted.     

发展性阅读障碍者的快速命名缺陷

快速命名任务是一种需要命名多个高熟悉项目的认知任务,尤其适合用来对成因复杂的发展性阅读障碍进行研究。许多研究者使用不同类型的快速命名任务发现,发展性阅读障碍者的快速命名缺陷在眼动过程表现为中央凹和副中央凹的加工困难,在认知过程中表现为抑制能力较差等。未来的研究中应该注意到快速命名缺陷的复杂性,采用多种方法相结合的方式来探究快速命名缺陷的本质,从而建立系统性的假说。