Facilitation of Sodium Aversion Learning in Sodium-Deprived Rats

Two experiments with rats explored the effects of sodium deprivation induced by furosemide injections upon acquisition of taste aversion to sodium chloride (NaCl). In Experiment 1, rats under either sodium deprivation or a balanced nutrition condition were given access to a limited amount of NaCl solution prior to poisoning. When all rats were tested under sodium repletion, the previously sodium-deprived rats consumed less NaCl than did the nondeprived rats. This finding was replicated in Experiment 2A in which ingestion of a compound solution of NaCl and hydrochloric acid (HCl) was followed by poisoning. Consumption of HCl, however, showed the opposite pattern: the sodium-deprived rats drank more HCl than did the nondeprived rats, a result that was replicated in Experiment 2B. These results suggest that sodium deprivation strengthens the salience of NaCl, thereby facilitating acquisition of aversion to this taste and strongly overshadowing that to a simultaneously presented taste.     

Specifying the scope of 13-month-olds'' expectations for novel words

Recent research has documented that for infants as young as 12–13 months of age, novel words (both count nouns and adjectives) highlight commonalities among objects and, in this way, foster the formation of object categories. The current experiment was designed to capture more precisely the scope of this phenomenon. We asked whether novel words (count nouns; adjectives) are linked specifically to category-based commonalities from the start, or whether they also direct infants' attention to a wider range of commonalities, including property-based commonalities among objects (e.g. color, texture). The results indicate that by 12–13 months, (1) infants have begun to distinguish between novel words presented as count nouns versus. adjectives in fluent, infant-directed speech, and (2) infants expectations for novel words accord with this emerging sensitivity.     

Factors which Improve the Construct Validity of Assessment Centers: A Review

This article reviews 21 studies which manipulated specific variables to determine their impact on the construct validity of assessment centers. This review shows that the studies regarding the impact of different observation, evaluation, and integration procedures yielded mixed results. Conversely, dimension factors (number, conceptual distinctiveness, and transparency), assessor factors (type of assessor and type of assessor training), and exercise factors (exercise form and use of role-players) were found to moderate construct validity. On the basis of the review, practical recommendations are derived to maximize the probability that practitioners design and administer an assessment center with construct validity. Finally, new perspectives for future research are identified.     

Assessing Leadership Potential with a Biographical Measure of Personality Traits

The aim of this study was to demonstrate the feasibility of biographical inventories free of the limitations common to many current biographical measures by constructing and validating an inventory composed of homogeneous scales, with item content that is factual and fair, to assess personality traits predictive of leadership. The experimental inventory, with tentative scales for Dominance, Emotional Stability, Need for Achievement, Self-Confidence, and Sociability, was administered to incoming midshipmen at the US Naval Academy and item analyzed. The validity of the final scales was appraised against subsequent peer ratings of the traits and of leadership shortly after entering the Academy; military performance grades, and midshipman rank and leadership position at the Academy; and recommendations for promotion after graduating and serving as an officer. The Sociability, Dominance, and Need for Achievement scales demonstrated convergent and discriminant validity, and all of the scales except Self-Confidence correlated with the leadership criteria. The Sociability scale’s consistent correlations with several of the leadership criteria, including a nontrivial correlation (r = 0.28) with the leadership peer rating, implies that this measure may be useful in assessing leadership potential.     

Book Reviews

John T. Haworth Work, Leisure and Well-being Owen Hargie The Handbook of Communication Skills Richard Lepsinger and Anntoinette D. Lucia The Art and Science of 360° Feedback Kevin Murphy Individual differences and behavior in organizations     

The Timing of Conscious Experience: A Critical Review and Reinterpretation of Libet''s Research

An extended examination of Libet's works led to a comprehensive reinterpretation of his results. According to this reinterpretation, the Minimum Train Duration of electrical brain stimulation should be considered as the time needed to create a brain stimulus efficient for producing conscious sensation and not as a basis for inferring the latency for conscious sensation of peripheral origin. Latency for conscious sensation with brain stimulation may occurafterthe Minimum Train Duration. Backward masking with cortical stimuli suggests a 125–300 ms minimum value for the latency for conscious sensation of threshold skin stimuli. Backward enhancement is not suitable for inferring this latency. For determining temporal relations between stimuli that correspond to subjects' reports, theendof cerebral Minimum Train Duration should be used as reference, rather than its onset. Results of coupling peripheral and cortical stimuli are explained by a latency after the cortical Minimum Train Duration, having roughly the same duration as the latency for supraliminal skin stimuli. Results of coupling peripheral stimuli and stimuli to medial lemniscus (LM) are explained by a shorter LM latency and/or a longer peripheral latency. This interpretation suggests a 230 ms minimum value for the latency for conscious sensation of somatosensory near-threshold stimuli. The backward referral hypothesis, as formulated by Libet, should not be retained. Long readiness potentials preceding spontaneous conscious or nonconscious movements suggest that both kinds of movement are nonconsciously initiated. The validity of Libet's measures of W and M moments (Libet et al., 1983a) is questionable due to problems involving latencies, training, and introspective distinction of W and M. Veto of intended actions may be initially nonconscious but dependent on conscious awareness.     

汉字材料的性质对视觉短时记忆广度影响的实验研究

汉字材料的熟悉性和复杂性对视觉短时记忆（ＶＳＴＭ）广度的影响研究存在分析。本研究在实验设计上区分了汉语字词的熟悉性和复杂性维度,探讨了它们对ＶＳＴＭ广义的不同影响程度,结果表明：（１）材料的熟悉性是影响汉语字词ＶＳＴＭ广度的最重要因素,材料的复杂性影响不大;（２）在材料熟悉程度一致,被试在１１－２０岁年龄范围条件下,汉语字词ＶＳＴＭ广义将保持相对恒定（３）在承认“组块假说”的前提,汉语字词ＶＳＴＭ     

TRAINING PEERS TO TUTOR: EVALUATION OF A TUTOR TRAINING PACKAGE FOR PRIMARY LEARNING DISABLED STUDENTS

Peer tutoring—academic instruction given by a student to a same-aged classmate—can be a cost-effective way of providing needed instruction in the typical classroom where one teacher must deal with many students of varying ability levels. This study evaluated an instructional package as a training method for increasing the use of selected tutoring behaviors by peer tutors. Nine male students, aged 7 to 9 years, from a learning disabilities resource room served as subjects; four subjects served as tutors, four as students, and one as a generalization student who was assigned to all tutors during generalization testing. Subjects were assigned to tutor-student pairs based on their performances on a pretest of the 220 Dolch Basic Sight Words, with the subjects scoring highest on the pretest serving as tutors. Each tutor worked with his assigned student throughout the study, except for pre- and posttest sessions with the generalization student. During daily sessions, tutors trained their students to recognize sight words using 10 flash cards, each with 1 of the Dolch words printed on it. Training was conducted with all four tutors in a group and was evaluated using a multiple baseline design across three classes of tutoring behaviors: Preparation Behaviors, Prompting Behaviors, and Praising Behaviors. Training consisted of: (a) verbal instructions on how to perform the tutoring behaviors; (b) charts illustrating the appropriate tutoring behaviors with stick figures; (c) role playing with each tutor with the experimenter playing the part of the student and giving feedback and verbal reinforcement to the tutor for performance of the appropriate tutoring behaviors; and (d) verbal testing of each tutor by asking him to state orally the behaviors he was to perform. Training sessions took approximately 30 minutes for each of the 3 classes of tutoring behaviors. Results showed an increased use of tutoring behaviors by tutors as a function of the instructional package. Increases in tutoring behaviors were also observed during postintervention generalization testing of tutors instructing their regular student in new subject matter (math). Data taken from pre-, mid-, and postintervention testing of the 220 Dolch Words showed an increase of identifiable sight words by both students and tutors after completing the peer tutoring program. This study demonstrates that a simple tutor training package can be employed to teach young, special education students to serve as effective tutors for their peers. In addition, the academic gains evidenced by the subjects lend positive support to the effectiveness of peer tutoring programs and specifically to the research of Dineen, Clark, and Risley (Journal of Applied Behavior Analysis, 1977, 10 , 231–238) which demonstrated the educational benefits of tutoring incurred by the tutor as well as by the student.     

儿童最初词汇的获得及其过程

本文追踪研究了两名儿童获得最初词汇的过程。结果表明:在儿童最初语音发展过程中,所发出的音节日益丰富、分化,产生了连续音节,随意性和指向性逐渐增强。儿童获得最初词汇的过程,是连续音节逐渐被有指向的词取代的过程。根据连续音节和有指向的词的比例及沟通作用的变化,儿童获得最初词汇的过程可分为各具特点的三个阶段。两名儿童的最初词汇在其词类构成和功能意义上具有很高的一致性。结合两名儿童之间的个别差异,本文还初步探讨影响儿童获得最初词汇的因素——言语中枢和言语器官的发展、认知的发展,并探讨它们之间可能存在的相互关系。     

汉语阅读发展研究中几种实验任务之间关系的探讨

本研究综合考察汉语阅读获得与发展研究中经常使用的注音、命名与组词,听写与多重选择的关系。结果发现：注音与命名有很强的一致性,并且都与组词有很高的棚关;在这些任务中,听写的难度最大,多重选择最易;几种任务存在共同的加工规律。文章从词汇识别过程讨论了这些结果的理论含义。