Within-compound associations of taste and temperature

In two experiments, rats were given exposures to two solutions of different tastes (sucrose or sodium chloride) at two different temperatures (warm or cold). In Experiment 1, the rats were then given either one of the tastes at room temperature followed by LiCl injections, or distilled water at one of the temperatures followed by LiCl injections. Rats poisoned after drinking a taste were then given a choice between distilled water at the two temperatures, while those poisoned after drinking distilled water at a temperature were given a choice between the two flavors at room temperature. Rats drank less of the solution that contained the stimulus previously paired with the poisoned cue, demonstrating within-compound associations of tastes and temperatures. Experiment 2 found that tastes were better conditioned in a taste aversion procedure when the taste-temperature compound was the same during conditioning as during preexposure. This result is interpreted as evidence against a view of within-compound learning that treats the compound as a unitary stimulus.     

HIV-related neuropsychological impairment and immunodeficiency. CD8+ lymphocytes and neopterin are related to HIV-encephalopathy

The relationship between neuropsychological test performance and immunological parameters was studied in 52 HIV-positive patients within different stages of the infection. All subjects were neuropsychologically tested, the CD4 + and CD8 4- lymphocyte count were measured in peripheral blood, and the concentration of neopterin and HIV-p24 antigen were measured in serum. Ten patients with AIDS were defined as neuropsychologically impaired. The CD8 + cell count was the only immunological parameter that could significantly discriminate between AIDS patients with and without neuropsychological impairment. For the total group, significant positive correlations were found between neuropsychological test results and the number of CD8 + and CD4 + lymphocytes, and significant negative correlations were observed between serum concentration of neopterin and neurocognitive function. Regression analyses showed that up to 51% of the variance in test performance could be explained by CD8 + cells and neopterin concentration. The possible role of CD8 + lymphocytes and neopterin in the pathogenesis of HIV-related CNS-dysfunction is discussed.     

经典氧债学说研究进展

Hill和 Margaria等依据乳酸代谢动力学特征对氧债现象所作的理论解释曾统治对该问题的研究长达半个世纪 ,然而 ,采用新的测试技术研究发现 ,经典氧债学说至少在以下三个方面与当代生理学研究有明显的冲突 ,即氧亏与氧债的关系、乳酸与氧耗的一致性和乳酸转变为肌糖。本文就上述研究进行简要回顾。     

Relationships among several methods of linearly constrained correspondence analysis

This paper shows essential equivalences among several methods of linearly constrained correspondence analysis. They include Fisher's method of additive scoring, Hayashi's second type of quantification method, ter Braak's canonical correspondence analysis, Nishisato's type of quantification method, ter Braak's canonical correspondence analysis, Nishisato's ANOVA of categorical data, correspondence analysis of manipulated contingency tables, Böckenholt and Böckenholt's least squares canonical analysis with linear constraints, and van der Heijden and Meijerink's zero average restrictions. These methods fall into one of two classes of methods corresponding to two alternative ways of imposing linear constraints, the reparametrization method and the null space method. A connection between the two is established through Khatri's lemma.The work reported in this paper has been supported by grant A6394 from the Natural Sciences and Engineering Research Council of Canada to the first author. We wish to thank Carolyn Anderson, Ulf Böckenholt, Henk Kiers, Shizuhiko Nishisato, Jim Ramsay, Tadashi Shibayama, Cajo ter Braak, and Peter van der Heijden for their helpful comments on earlier drafts of this paper.     

Differential effects of massage and heelstick procedures on transcutaneous oxygen tension in preterm neonates

The present study investigated the differential effects of heelsticks and tactile-kinesthetic massage on transcutaneous oxygen tension (TcPO₂) in preterm infants. The sample was comprised of 37 stabilized preterm neonates from the Neonatal Intensive Care Unit. During the heelstick procedure, TcPO₂ significantly declined an average of 14 mmHg. When compared to the tactile-kinesthetic massage, TcPO₂ levels during the heelstick (M = 39.8) were significantly lower than during the stimulation (M = 72.8). Mean TcPO₂ levels remained clinically safe during the four massage sessions evaluated. The TcPO₂ levels during kinesthetic stimulation were somewhat more varied, and movement and pressurization of the TcPO₂ electrode were investigated as possible artifactual explanations for this phenomenon. Overall, the findings indicate that social forms of touch such as tactile-kinesthetic massage do not appear to have a medically compromising effect on TcPO₂ in the preterm neonate. These findings are evaluated in relation to the “minimal touch” policy, and implications for future handling of the stabilized preterm neonate are discussed.     

Resolutions to interpretive dilemmas created by the minnesota multiphasic personality inventory 2 (MMPI-2): A reply to Strassberg

We discuss the interpretive dilemmas identified by Strassberg (1991) and propose to resolve these dilemmas by pointing out that some change has indeed been introduced in the MMPI-2 and that change is a necessary requisite for improvement. Changes in administration procedures used with the MMPI-2 normative sample should only improve the quality of the normative data; changes in the way T-scores were developed lead to minimal change in the profile but enable more accurate interpretation of differences between scales on an individual's profile; normative changes have a differential effect on the clinical scales and this is to be expected; and the problem of codetype congruence has been overestimated and overstated. We conclude that the change introduced in the MMPI-2 can only serve to improve the test.     

Lexical recognition of embedded unattended words: Some implications for reading processes

Two questions were addressed by these experiments. Firstly, do unattended words influence attended words only when they appear in isolation and thereby may attract attention, or are they influential even when embedded amongst ineffective material? Secondly, can the influence of an unattended display be increased by increasing the number of potentially effective words. By having observers give category names to attended words at the same time as masked unattended words appeared in a column to the right of fixation, experiment 1 found that a single word was effective even when embedded, and that an increasing effect was not observed with a display with a 50 msec duration. There was some evidence of a linear increase in the size of the effect with a 200 msec display, but evidence from experiment 2 suggests that subjects may have been aware of the unattended words when they were exposed for this duration. The results were discussed in relation to a model of eye-fixation control during reading which postulates that unattended words gain lexical recognition when they are semantically related to the attended activity. This lexical recognition may then serve to mark interesting locations in the text and attract future eye-fixations.     

Knowledge organization and skill differences in computer programmers

Like experts in other fields, expert computer programmers can recall at a glance far more information relevant to their field than novices can. One explanation for this difference is that experts not only have more information, they have it better organized into meaningful chunks. In this paper, we infer the details of individual programmers' chunks of key programming concepts using the Reitman—Rueter (Cognitive Psychology, 1980, 12(4), 554–581.) technique for inferring tree structures from recall orders. Differences in organizations accompany skill-level differences. Beginner programmers' organizations show a rich variety of common-language associations to these programming concepts; Intermediate programmers show mixtures of programming and common-language associations; and Experts show remarkably similar, but not identical, organizations based clearly on programming knowledge.     

The effects of cue distinctiveness on infants' manual search

Nine- and sixteen-month-old infants were repeatedly presented a manual search problem in which a toy was hidden in one of two containers, which were then moved into reach. The distinctiveness of the containers or their closeness during the movement was varied in different conditions. Overall, the older infants performed better than younger infants, performance improved across trials, and there were more correct searches when the containers or trajectories were distinctive. Analyses of visual orienting indicated that infants learned to restrict their looking to the hiding place. The ability to maintain attention to discriminative cues may be instrumental to progress in delayed-reaction and object permanence tasks.     

Stimulus control of information processing in pigeon short-term memory

Six pigeons were trained initially on a delayed successive matching-to-sample task using red and green fields as sample and test stimuli. Following acquisition, each sample was followed either by a vertical line (“remember” cue), which indicated that sample memory would be tested, or by a horizontal line (“forget” cue), which indicated that sample memory would not be tested. During the experiments, sample memory on forget trials was tested occasionally. A series of five experiments revealed: (a) better retention on remember trials than on forget trials, (b) increased effectiveness of a forget cue when it followed closely sample offset, (c) more rapid forgetting over a retention interval ranging from 3 to 6 sec on forget trials than on remember trials, (d) a “cancellation” effect in which a remember cue which followed immediately the offset of a forget cue attenuated markedly the effectiveness of the forget cue, and (e) an “insulation” effect in which the effectiveness of a forget cue was reduced considerably when presented after a remember cue. It was concluded that pigeons actively process or rehearse the sample memory during the retention interval.