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1.
Irrelevant background speech disrupts serial recall of visually presented lists of verbal material. In 4 experiments, the hypothesis that this disruption is due to the phonological similarity of the irrelevant sound and the list to be recalled was tested. In Experiment 1, item length was controlled and a large irrelevant speech effect was found, but the effect of phonological similarity was small and confined to recency. In Experiment 2, words in the irrelevant stream were used, and the experiment showed an irrelevant speech effect in which phonological similarity played a small part. Experiments 3 and 4 found that similarity (rhyming) within the irrelevant sound stream decreased the level of disruption, and the effect was more marked when the visually presented lists contained items that did not rhyme with one another. Rather than supporting a phonological similarity hypothesis, the results support a changing state hypothesis. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   

2.
In female mice on a control diet (3.6% fat) reduced physical activity leads to a reduction of the average life span. So the average age at death of an inactive group is 500 +/- 166 compared to 565 +/- 175 days in an active control group. If the animals are kept on a fat rich diet (12.4% fat) this effect of physical activity restriction is no longer observable and the average age at death is 570 +/- 142 days, within the range of the control animals. The increased fat intake seems to reduce the stress or to increase the resistance to stress in the activity restricted animals. So stress is a crucial determinant of life span.  相似文献   

3.
OBJECTIVES: We sought to evaluate the efficacy of alpha-adrenergic blocking agents in counteracting left ventricular (LV) dysfunction occurring after transient ischemia in humans. BACKGROUND: The mechanisms underlying postischemic LV dysfunction are largely unknown. METHODS: Percutaneous transluminal coronary angioplasty (PTCA) provides a clinical model of ischemia and reperfusion. In 50 patients undergoing coronary stenting for 77+/-5% stenosis, LV function was monitored by transesophageal echocardiography during and 30-min after PTCA. Fifteen minutes after stenting, 15 patients received 12 microg/kg body weight of the alpha-blocker phentolamine intracoronarily, 15 patients received 600 microg/kg of the alpha1-blocker urapidil intravenously, 10 patients received the combination of phentolamine and 1.2 mg of propranolol intracoronarily, and 10 patients received saline. RESULTS: Fifteen minutes after successful coronary dilation, significant contractile dysfunction occurred in previously ischemic and nonischemic myocardium. LV dysfunction was accompanied by an increase in coronary resistance and diffuse vasoconstriction. Alpha-blockers counteracted LV dysfunction and coronary resistance and the increase in vasoconstriction. Phentolamine and urapidil increased global LV shortening from 34+/-9% to 45+/-8% and to 49+/-8%, respectively (p < 0.05). After the administration of propranolol combined with phentolamine, LV dysfunction remained unchanged (34+/-6%), as in control subjects. CONCLUSIONS: LV dysfunction occurs after PTCA, as described in animal models after ischemia. Alpha-blockers abolished LV, macrocirculatory and microcirculatory dysfunction, whereas the alpha-blocker effect was prevented by combining alpha- and beta-blockers. The evidence of diffuse rather than regional dysfunction, together with the opposite effects of alpha- and beta-blockade, supports the hypothesis of neural mechanisms eliciting postischemic LV dysfunction.  相似文献   

4.
This paper attempts to establish whether dissatisfaction with the artificial limb and/or body image relate to achieved mobility following lower limb amputation in established limb wearers. Patients attending limb fitting clinics (n = 107, 62% male, mean time from amputation 13.9 years; range 1-54) participated. The measures were a specially designed Attitude to Artificial Limbs Questionnaire, a Body Image Questionnaire adapted from an eating disorders instrument including reference to body shape, the Hospital Anxiety and Depression Scale and the Harold Wood Stanmore Mobility Scale. The rehabilitation physician rated prosthetic suitability on a Numerical Rating Scale. The results showed patients were moderately satisfied with their artificial limb, had little experience of body image disruption or distress and there was no overall relationship between these variables and mobility. However, those with a more negative body image were more anxious and in younger patients who sustained more traumatic than vascular amputations, the correlation between body image and mobility was significant, anxiety was higher and physician satisfaction with the prosthesis was lower. It is concluded that body image disruption, anxiety and depression are not common in established limb wearers except in young people with traumatic amputations.  相似文献   

5.
The purpose of this study was to investigate the importance of an intact endothelial cell layer for the direct antiatherogenic effect of estrogen on the arterial wall. Thirty rabbits were bilaterally ovariectomized and subjected to mechanical injury of the endothelium by balloon catheterization of the upper thoracic aorta. Immediately after the operation, treatment was initiated with either 17 beta-estradiol or placebo given intramuscularly. All rabbits were clamped at a similar plasma cholesterol level from 1 week before the operation until the experiment was terminated 13 weeks later. In the undamaged aorta, ie, the aortic arch, the lower thoracic aorta, and the upper abdominal aorta, the estrogen-treated rabbits had one third (P = .06), one sixth (P = .002), and one seventh (P = .001), respectively, the accumulation of cholesterol of the placebo-treated rabbits. In the upper thoracic aorta that had been subjected to mechanical injury of the endothelium, however, aortic cholesterol accumulation was not significantly different between the two groups. Similar results were obtained by histological evaluation of the aortic tissues. Immunohistochemical staining with antibodies against macrophages, smooth muscle cells, and T lymphocytes revealed no significant differences in the intimal distribution of cells between estrogen- and placebo-treated rabbits, except for a higher number of T lymphocytes per unit intimal area of the undamaged aortic arch (P < .0005) in the estrogen-treated-rabbits than the placebo-treated rabbits. This is the first study to demonstrate that the antiatherogenic effect of estrogen is abolished by balloon catheter injury in cholesterol-clamped rabbits. These results may indicate that an intact endothelial cell layer is crucial for the direct antiatherogenic effect of estrogen on the arterial wall.  相似文献   

6.
The presynaptic protein alpha-synuclein has been implicated in the pathogenesis of Parkinson's disease. First, two missense mutations A30P and A53T cause inheritable early onset Parkinson's disease in some families. Secondly, alpha-synuclein is present in Lewy bodies of affected nerve cells in the predominant sporadic type of Parkinson's disease as well as in dementia with Lewy bodies. We demonstrate in the rat optic system that a portion of alpha-synuclein is carried by the vesicle-moving fast component of axonal transport and that it binds to rat brain vesicles through its amino-terminal repeat region. We find alpha-synuclein with the A30P mutation of familial Parkinson's disease devoid of vesicle-binding activity and propose that mutant alpha-synuclein may accumulate, leading to assembly into Lewy body filaments.  相似文献   

7.
The purpose of this study was to compare the effect, both in vitro and in vivo, of cefepime with those of four other cephalosporins, namely ceftriaxone, cefotaxime, cefuroxime and cephalothin, against penicillin-resistant pneumococci. One hundred pneumococcal strains, 31 penicillin-susceptible, 30 penicillin-intermediate-resistant and 39 penicillin-resistant pneumococci, were used in MIC studies. Time-kill experiments were carried out for four strains. In the mouse peritonitis model, the dose that gave protection to 50% of mice challenged with a lethal dose of pneumococci (ED50) was determined for three pneumococci and five cephalosporins. The MICs of all five cephalosporins and penicillin correlated significantly with each other. In vitro, the most potent cephalosporins against pneumococci were cefotaxime, ceftriaxone and cefepime, followed by cefuroxime and cephalothin. In time-kill experiments, carried out for four pneumococci, no differences were found in the killing effect of these five cephalosporins in relation to MICs. In the mouse peritonitis model, there was no significant correlation between log(MIC) and log(ED50) for the five cephalosporins against three pneumococci (Spearman's rho = 0.39, P = 0.16). However, if the values for cefepime against the three pneumococci were excluded, there was a significant correlation for the remaining four cephalosporins (Spearman's rho = 0.62, P = 0.04). For all three pneumococci, the ED50s of cefepime were lower than expected from the MICs. It was not possible to explain this beneficial difference in the effect of cefepime in terms of in-vitro bactericidal activities, serum protein binding or pharmacodynamic parameters.  相似文献   

8.
"An experiment was designed to study children's preferences for a series of problem-solving tasks as a function of the particular reinforcement condition associated with a training task, and the degree of similarity of each task to the training task… negative reinforcement produced in some S's approach gradients and in others avoidance gradients. The meaning of the results was discussed and related to motivation theory. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   

9.
It has been recently argued that human bodies are processed by a specialized processing mechanism. Central evidence was that body inversion reduces recognition abilities (body inversion effect; BIE) as much as it does for faces, but more than for other objects. Here we showed that the BIE is markedly reduced for headless bodies and examined the reason for this unexpected finding. Two alternative hypotheses were examined. Either the BIE is reduced for any type of incomplete body, or the head plays a special role in discrimination of body posture. Results show that omission of other body parts (leg or arms) did not influence the magnitude of the BIE relative to complete bodies. Analogous manipulations with faces did not influence the magnitude of the face inversion effect. Importantly, similar to effects we found for headless bodies, discrimination abilities for upright bodies and the BIE were markedly reduced for complete bodies that did not differ in head posture. We conclude that intact discrimination of body posture relies heavily on the head position. Our findings also imply that the BIE and the face inversion effect may be generated by different mechanisms. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   

10.
Latent inhibition (LI) refers to the retardation in learning about the significance of a neutral stimulus that results from its nonreinforced preexposure. There is evidence that electrolytic or aspiration lesions of the hippocampal formation can disrupt LI (I. Weiner, see record 1991-06652-001). It has been suggested that this effect may stem from the interruption of a projection from the retrohippocampal region to the nucleus accumbens (A. J. M. Clark et al, 1992). The present experiment assessed this possibility by comparing LI in rats with retrohippocampal N-methyl-D-aspartate (NMDA) lesions extending from the entorhinal cortex to the ventral subiculum to that seen in vehicle controls and unoperated controls. LI was abolished by the retrohippocampal lesion. The effect of the lesion on LI was prevented by treatment with systemic haloperidol (0.2 mg/kg). The results are discussed with respect to an animal model of schizophrenia. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   

11.
According to a conceptual similarity interpretation of personality and interpersonal assessment ratings, such ratings are primarily understandable as linguistic artifacts having little or no connection with the real world. This position contravenes a central and widely used methodology of personality and behavior assessment. The present experiment evaluated the logic and data that have been used to support this conceptual similarity explanation and concludes that pertinent evidence is wanting. A reply to R. A. Shweder and R. G. D'Andrade's (see record 1980-29282-001) response to the present article is also included. (55 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   

12.
59 undergraduates assuming the role of bank-loan committee member, rated loan applicants as to probability of delinquency in loan repayment, and recommended loan magnitudes. Ss (a) expressed greater attraction to applicants with similar attitudes and to applicants with good credit ratings; (b) displayed less conservatism (the difference between the rated delinquency probability and the optimal probability of Bayes's theorem) under high attitude similarity and favorable conditions, and (c) approved larger loans for similar applicants than dissimilar ones. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   

13.
OBJECTIVES: It is generally believe that lipoprotein(a) (Lp(a)) levels remain relatively constant in the same individual, but there is a paucity of data to substantiate this belief. This study was undertaken to determine the extent of intra-individual variation in Lp(a) over a 12-month period. DESIGN AND METHODS: Lp(a) was measured monthly in duplicate over a 12-month period in 11 females and 11 males who were healthy, free-living, normal subjects by the Incstar Immunoprecipitin method using a goat antibody which was monospecific for Lp(a). RESULTS: Some subjects showed considerable month-to-month variations which were not correlated with changes in other lipid parameters or with weight. Others showed fairly constant Lp(a) levels, with a few values which were quite different from the rest. This was not attributable to methodological factors; low and high controls gave mean (mg/L), SD and CV values of 181, 8.6, 4.7 and 431, 14, 3.3, respectively. The difference between the minimum and maximum values in the same individuals ranged from a low of 14 mg/L in one subject to a high of 229 mg/L in another over the one-year period. CONCLUSIONS: Lp(a) showed greater intra-individual variations in normal subjects than is commonly believed. It is therefore recommended that Lp(a) should be measured sequentially over a few weeks to arrive at a mean value for assessing risk of coronary heart disease.  相似文献   

14.
Models of attentional selection are based on either stimulus-driven or goal-directed processes. Support for the latter comes from a study showing that a salient singleton in a search display can be ignored when the target has a different defining feature (Kumada, 1999). We show that this finding holds only when the target and the nonsalient distractors are highly dissimilar from one another. When the target and the distractors are made more similar, whilst ensuring that the target still pops out of the display, the salient distractor can no longer be ignored. This outcome is consistent with predictions from stimulus-driven accounts. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   

15.
Recent studies suggest that timing and tasks involving executive control processes might require the same attentional resources. This should lead to interference when timing and executive tasks are executed concurrently. This study examined the interference between timing and task switching, an executive function. In 4 experiments, memory search and digit classification were performed successively in 4 conditions: search–search (search followed by search), search–digit, digit–search, and digit–digit. In a control reaction time (RT) condition, participants provided RT responses in each of the 2 tasks. In a time production condition, an RT response was provided to the first stimulus, but the response to the second stimulus, S2, was given only when participants judged that a previously presented target duration had elapsed. When responding to S2 required a switch, RTs to S2 were longer, but produced intervals were unaffected. These results show that memory search affects concurrent timing, but not task switching. Task switching seems therefore to be 1 executive function that does not interfer with timing. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   

16.
The effects of somatosensory stimulation on the regional cerebral blood flow (rCBF) response were studied in unanesthetized monkeys before and after treatment with scopolamine and three cognitive enhancers (physostigmine, E2020 and tacrine) that inhibit cholinesterase, using 15O-labeled water and high-resolution positron emission tomography. Under control conditions, somatosensory stimulation induced a significant increase in the rCBF response in the contralateral somatosensory cortex of monkey brain. Intravenous administration of scopolamine (50 microg/kg) resulted in abolishment of the rCBF response to stimulation. The rCBF response abolished by pretreatment with scopolamine was recovered by administration of physostigmine (1 or 10 microg/kg), E2020 (10 or 100 microg/kg) or tacrine (100 or 1000 microg/kg), in a dose-dependent manner. The effect of E2020 (100 microg/kg) on the rCBF response lasted for >4 hr, whereas the effects of physostigmine and tacrine were of shorter duration. These findings suggest that these compounds reversed the scopolamine-abolished rCBF response to somatosensory stimulation via enhancement of cholinergic neurotransmission, which was mainly induced by cholinesterase inhibition.  相似文献   

17.
Sixty aphasic patients and 55 normal control subjects were tested on a sentence production protocol that required subjects to produce specific sentence types from semantic representations. Normal subjects produced the expected targets with great reliability. Analysis of the patients' performance indicated that patients had difficulty producing both grammatical forms and thematic roles. Patients had more trouble producing grammatical elements than content words, and showed differential difficulty on sentence types that had more grammatical elements and in which the order of thematic roles was non-canonical. The results provide evidence regarding the processing load imposed by different components of the sentence production process.  相似文献   

18.
In cells infected by herpes simplex virus type 1 (HSV1), a series of nuclear changes can be observed in a temporal sequence. Such changes are related to important modifications in the higher-order structure of host cell chromatin, such as loss of DNA loop supercoiling and wholesale DNA loop disorganization. It is known that the topological relationship between DNA and the nuclear substructure is a critical factor for proper nuclear physiology. Here we report that the usual association between newly replicated DNA and the nuclear substructure, commonly known as nuclear matrix, is abrogated in cells infected by HSV1, thus establishing a correlation between the virus-induced modifications in chromatin higher-order structure and a major biochemical change within the infected cell nucleus.  相似文献   

19.
Children are sometimes called 'egocentric' on the basis of their performance on Piagetian spatial-inference tasks. They often inappropriately substitute their own perceptual report for another observer's. Little is known about what responses are activated in giving perceptual reports. An experiment is presented which tightly controls spatial and temporal stimulus ordering. One condition elicted reports of that aspect of the display which children could not see instead of what they could see. Explanations are considered on the basis of relational coding and temporal responsiveness.  相似文献   

20.
A category classification task was administered to participants in their twenties through their eighties. Participants studied a set of high distortions of a prototype dot pattern and were then asked to choose whether or not a new set of dot patterns (random patterns, high distortions, low distortions, and the prototype) belonged to the same category of dot patterns as studied. Participants were also administered a recognition test after studying a second set of dot patterns. There were no significant differences for age groups on the pattern recognition test. In 2 of the 3 analyses of the category classification task, there were no significant age effects. However, there was a small age effect in one analysis with the young making more accurate classifications on two aspects of the task. The results are consistent with the view that small age-related effects may exist for some tests of nondeclarative memory.  相似文献   

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