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1.
1. Desensitization of ET(A) endothelin receptor (ET(A)R) was compared between the rat and guinea-pig with regard to negative chronotropic response (NC) in the right atria (RA). 2. ET-1 (100 nM) produced distinct NC in the presence of BQ788 (300 nM), and positive chronotropic response (PC) in the presence of BQ123 (1 microM) in both species, showing that ETAR and ET(B) endothelin receptor (ET(B)R) mediate NC and PC, respectively. 3. Repetitive applications of ET-1 (50 nM) desensitized PC, and the second application only induced a strong NC in both species. Later applications of ET-1 produced virtually no response in the rat RA, whereas they produced BQ123-sensitive NCs repetitively in guinea-pig RA, exhibiting marked species difference in desensitization of ETAR-mediated NC. 4. Pretreatment with staurosporine (100 nM) prevented desensitization of ET(A)R in the rat RA altogether. However, phorbol 12-myristate 13-acetate (PMA, 300 nM) failed to induce, but rather hampered, desensitization of ET(A)R. 5. Partial amino acid sequencing of ET(A)Rs, spanning from the 2nd through the 4th intracellular loops, revealed that all the potential Ser/Thr phosphorylation sites, including a protein kinase C (PKC) site, are conserved among guinea-pigs, rats, rabbits, bovines and humans. 6. In guinea pig RA, pretreatment with okadaic acid (1 microg ml(-1)) and PMA did not facilitate desensitization of ET(A)R whereas these agents successfully desensitized ETAR during combined stimulation of beta-adrenoceptor and ET(A)R by isoproterenol (300 nM) and ET-1 (100 nM). 7. These results suggest that species differences in desensitization of ET(A)R are not caused by differences in the site(s) of, but caused by differences in the environment for phosphorylation of the receptor. Desensitization of ET(A)R appears to require phosphorylation of the receptor by PKC as well as a kinase stimulated by beta-adrenoceptor activation.  相似文献   

2.
The acoustic confusion effect is the finding that lists of to-be-remembered items that sound similar to one another are recalled worse than otherwise comparable lists of items that sound different. Previous work has shown that concurrent irrelevant speech and concurrent irrelevant tapping both reduce the size of this effect, suggesting similarities between the two manipulations. The authors assessed the relation between irrelevant speech and irrelevant tapping by correlating the disruption each causes to recall of similar- and dissimilar-sounding items. A significant correlation was obtained, indicating a relation between the two. The results indicate that researchers should be sensitive to changes in the magnitude of the effects rather than focusing exclusively on the presence or absence of particular effects. Implications for the 3 major explanations of the irrelevant speech effect are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   

3.
Comments on I. Silverman (see record 1972-02778-001) and encourages him to devote his methodological efforts to areas in which realistic contributions can be made to the improvement of society and of social psychology (in that order). (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   

4.
The ability to attend to relevant events and to ignore irrelevant stimuli is crucial to survival. Theories disagree on whether this ability is dependent solely on increased neural activation for relevant items or whether active ignoring can also play a role. The authors examined the active ignoring of stimuli using a preview search procedure, where irrelevant faces appeared prior to relevant house stimuli. They found increased activation in brain regions associated with spatial memory and in content-specific face-processing areas when participants ignored the irrelevant faces. Differences arose even on trials when only previewed faces appeared, and the magnitude of these differences predicted how well faces were ignored in search. Activation associated with active ignoring decreased when a secondary task was imposed during the preview. The data reveal a neural marker for the process of actively ignoring the content and locations of irrelevant stimuli. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   

5.
The unmet needs of our nation's children and families have continued to increase, especially for impoverished and minority populations. In response, there has been growing support for a service integration approach that emphasizes interagency and interdisciplinary coordination and collaboration, particularly with respect to the role of schools. The American Psychological Association (APA) Task Force on Comprehensive and Coordinated Psychological Services for Children Ages 0–10 endorsed the service integration model and called for professional psychology to take a leadership role in its development, refinement, implementation, and evaluation. The APA adopted these recommendations as policy. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   

6.
Four experiments investigated attentional capture by a color singleton in visual search for a nonsingleton target. B. S. Gibson and E. M. Kelsey (1998) found that a color singleton in a precuing array facilitated target discrimination at that location if the same color also signaled the target array onset. The authors found similar cuing effects regardless of whether the singleton color matched the target array and regardless of whether subjects could anticipate the singleton or target-array color. In Experiment 4, a color singleton captured attention when it appeared in the precuing array but not when it appeared in the target array. The results indicate that attentional control settings for displaywide attributes are imprecise: Although subjects may anticipate a specific color, they cannot avoid attentional capture by other irrelevant colors. In addition, the effect of irrelevant singletons depends on whether a target is simultaneously present in the array. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   

7.
Irrelevant auditory stimuli disrupt immediate serial recall. In the equipotentiality hypothesis, D. M. Jones and W. J. Macken (see record 1993-20312-001) made the controversial prediction that speech and tones have an equivalent disruptive effect. In the present study, 5 experiments tested their hypothesis. Experiments 1–4 showed that meaningful speech disrupts recall more than do tones. Experiments 3 and 4 provided some evidence that meaningful speech disrupts recall more than does meaningless speech, and Experiment 4 showed that even meaningless speech disrupts recall more than do tones. Using slightly different experimental procedures, Experiment 5 showed that letters disrupt recall more than do tones. Implications of these results for a number of theories of primary memory and the irrelevant speech effect are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   

8.
Studied information-seeking performance under conditions of conflicting and irrelevant input information in an 8-choice task that was an abstracted version of a tactical decision problem faced by military commanders. 14 male undergraduates were required to purchase information from 3 fallible sources until they could decide which target was the object of an enemy advance. The earlier a correct choice was made, the greater the monetary payoff to the S. Results indicate that degree of information conflict and relevance had little influence on trial number and latency of correct choices, but a more marked impact on initial decisions. Ss purchased more information prior to 1st decisions when degree of relevance was low. Choice latencies of 1st decisions decreased with increasing relevance and decreasing conflict. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   

9.
We establish attentional capture by emotional distractor faces presented as a “singleton” in a search task in which the emotion is entirely irrelevant. Participants searched for a male (or female) target face among female (or male) faces and indicated whether the target face was tilted to the left or right. The presence (vs. absence) of an irrelevant emotional singleton expression (fearful, angry, or happy) in one of the distractor faces slowed search reaction times compared to the singleton absent or singleton target conditions. Facilitation for emotional singleton targets was found for the happy expression but not for the fearful or angry expressions. These effects were found irrespective of face gender and the failure of a singleton neutral face to capture attention among emotional faces rules out a visual odd-one-out account for the emotional capture. The present study thus establishes irrelevant, emotional, attentional capture. (PsycINFO Database Record (c) 2011 APA, all rights reserved)  相似文献   

10.
Young and older adults provided language samples in response to questions while walking, finger tapping, and ignoring speech or noise. The language samples were scored on 3 dimensions: fluency, complexity, and content. The hypothesis that working memory limitations affect speech production by older adults was tested by comparing baseline samples with those produced while the participants were performing the concurrent tasks. There were baseline differences: Older adults' speech was less fluent and less complex than young adults' speech. Young adults adopted a different strategy in response to the dual-task demands than older adults: They reduced sentence length and grammatical complexity. In contrast, older adults shifted to a reduced speech rate in the dual-task conditions. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   

11.
12.
The irrelevant speech effect is the impairment of immediate memory by the presentation of to-be-ignored speech stimuli. The irrelevant speech effect has been limited to serial recall, but this series of 8 experiments demonstrates that it is considerably more general. Exps 1–3 show that (1) irrelevant speech inhibits free recall more than does white noise, (2) irrelevant speech impairs free recall even when the speech occurs after the to-be-recalled items, and (3) free recall is inhibited even when the speech is meaningless. Exp 4 failed to find an effect in free recall with 16-item lists. Exps 5A–5C extend the effect to recognition of 8-, 12-, and 16-item lists, with both phonologically related and phonologically unrelated lure items. Exp 6 extends the effect to a cued recall task that discourages the use of serial rehearsal of the to-be-remembered items. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   

13.
Trained 14 jungle-born female pigtailed monkeys to criterion on 2 concurrently presented 4-choice object discriminations. In 1 problem form was relevant and color constant irrelevant; in the other, color was relevant and form constant irrelevant. Following training, Ss were given transfer tests with a 4-choice setting consisting of the 2 formerly rewarded objects, a 3rd object composed of the rewarded relevant features of the color and form discriminations, and a 4th object constructed from the 2 constant irrelevant color and form features. Ss consistently chose the previously rewarded objects during transfer, but of the new objects, almost always chose the object constructed of relevant features. A number of models for discrimination learning are considered in the light of these data. (17 ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   

14.
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16.
Investigated the importance of out-of-role Research in teacher evaluation. 60 administrators were presented 1 of 2 variations of a teacher's application form from which they assessed the personality traits of the teacher and indicated their interest in seeing the teacher for an interview. A multivariate analysis of variance revealed that altering responses for out-of-role behavior (positive vs negative) resulted in significantly lower trait ratings and less likelihood of an interview for the teacher with negative out-of-role behavior than for the teacher with positive out-of-role behavior (p  相似文献   

17.
Pigeons in two experiments were first trained with a set of simple discriminations of the form AX+ CX?, BY+ DY? where A, B, C, and D were relevant, and belonged to one dimension, and X and Y were irrelevant and belonged to a different dimension. They were then tested with a discrimination of the form AX+ AY? BX?. The experiments revealed that the discrimination between AX+ and BX? was acquired more readily than between AX+ and AY?, which indicates that the original training resulted in the associability of the relevant stimuli being greater than that of the irrelevant stimuli. Experiment 2 revealed that the status of other stimuli from the two dimensions influenced these changes in associability. The associability of X and Y was enhanced by making other stimuli from the same dimension relevant, and the associability of A and B was reduced by making other stimuli from the same dimension irrelevant. The associability of the stimuli is attributed to the attention they are paid. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   

18.
In 3 experiments, the effect of adding an irrelevant stimulus to a discrimination was examined. In Exp 1, a group of pigeons received autoshaping with an A+Bo discrimination in which 1 stimulus signaled food, A+, and a simultaneous compound of A with another stimulus, B, signaled the absence of food, ABo. A 2nd group received similiar training, except that a 3rd stimulus, C, was present in both types of trials, AC+BCo. The A+Bo discrimination was acquired more readily than the AC+BCo discrimination. Exps 2 and 3 used a negative-patterning design, A+Bo+. In both experiments, this problem was mastered more readily than when an irrelevant stimulus was used to create an AC+BCoC+ discrimination. The results fail to confirm predictions derived from elemental theories of conditioning. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   

19.
In a choice RT task, 64 undergraduates pressed either a right- or left-hand key in response to directional commands provided by 400- and 1000-cps tones. On monaural trials, RT was significantly faster when the meaning of the tonal command corresponded with the ear in which it was heard (corresponding trials) than when it did not (noncorresponding trials). A comparison of monaural with binaural RT indicated that this Tonal Command * Ear Stimulated interaction was due to interference on the noncorresponding monaural trials rather than facilitation on the corresponding trials. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   

20.
Two experiments were used to examine the effects of stress on latent inhibition (LI; poorer learning with a previously exposed irrelevant stimulus rather than a novel stimulus). In Experiment 1, stress was induced in college students by threatening participants' self-esteem with a difficult number series completion test that was related to intelligence. In Experiment 2, the participants were job seekers who were either informed or not that the LI test was part of the selection process. In both experiments, LI was attenuated in high- as compared with low-stressed participants. The results suggest that stress and/or anxiety impairs the inhibition of irrelevant-preexposed stimuli. Implications for understanding the impaired selective attentional processes in schizophrenia and schizotypy are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   

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