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161.
In 1957, Skinner, in his "Verbal Behavior", proposed an explanation on how a language is learned. In 1959, Chomsky strongly argued the non-learnability of language, establishing in the field of developmental psycholinguistics the substitution of the term "learning" for that of "acquisition". Currently, the constructivist models describe language acquisition as a process of ontogenetic, gradual, complex, and adaptive change. This new theoretical framework has been especially useful for rereading Verbal Behavior because it facilitates recovering the Skinnerian learning mechanisms. This can be observed in the recent research trends that recapture reinforcement and imitation (echoic responses), although they are now located in the initial phases of the process and are included in a cognitive dynamic that, by gradually increasing its complexity, can achieve grammar. The new constructivist theoretical framework, by retrieving the functional and referential aspects of language, can also take advantage of the classic Skinnerian proposal about the pragmatic types of verbal behavior, providing it with new meaning.  相似文献   
162.
The concept of informed consent was one of the most fruitful ideas that deeply changed the relationships between physicians and their patients from paternalism to respect for the personal autonomy of subjects needing professional medical care. The great progress in medicine, also involving the pharmaceutical industry, has created an increasing need to perform different clinical and experimental trials. The evolution of clinical research in the last decades has influenced strongly the design of these studies. One of the most important changes in this field has been the use of placebo groups in double-blind controlled studies. The controversies have involved not only the use of placebo when standard or proven treatment was available, but also some specific problems concerning the procedure of obtaining informed consent in such trials. This paper briefly presents the evolution of informed consent in Poland as well as different ethical and legal problems concerning informed consent and the use of placebo controls in clinical trials. An earlier version of this paper was presented at an international conference, “Placebo: Its Action and Place in Health Research Today,” held in Warsaw, Poland on 12–13 April, 2003.  相似文献   
163.
Single-unit, event-related potential (ERP), and neuroimaging studies have implicated the prefrontal cortex (PFC) in top-down control of attention and working memory. We conducted an experiment in patients with unilateral PFC damage (n=8) to assess the temporal kinetics of PFC-extrastriate interactions during visual attention. Subjects alternated attention between the left and the right hemifields in successive runs while they detected target stimuli embedded in streams of repetitive task-irrelevant stimuli (standards). The design enabled us to examine tonic (spatial selection) and phasic (feature selection) PFC-extrastriate interactions. PFC damage impaired performance in the visual field contralateral to lesions, as manifested by both larger reaction times and error rates. Assessment of the extrastriate P1 ERP revealed that the PFC exerts a tonic (spatial selection) excitatory input to the ipsilateral extrastriate cortex as early as 100 msec post stimulus delivery. The PFC exerts a second phasic (feature selection) excitatory extrastriate modulation from 180 to 300 msec, as evidenced by reductions in selection negativity after damage. Finally, reductions of the N2 ERP to target stimuli supports the notion that the PFC exerts a third phasic (target selection) signal necessary for successful template matching during postselection analysis of target features. The results provide electrophysiological evidence of three distinct tonic and phasic PFC inputs to the extrastriate cortex in the initial few hundred milliseconds of stimulus processing. Damage to this network appears to underlie the pervasive deficits in attention observed in patients with prefrontal lesions.  相似文献   
164.
Perceptual discrimination between speech sounds belonging to different phoneme categories is better than that between sounds falling within the same category. This property, known as "categorical perception," is weaker in children affected by dyslexia. Categorical perception develops from the predispositions of newborns for discriminating all potential phoneme categories in the world's languages. Predispositions that are not relevant for phoneme perception in the ambient language are usually deactivated during early childhood. However, the current study shows that dyslexic children maintain a higher sensitivity to phonemic distinctions irrelevant in their linguistic environment. This suggests that dyslexic children use an allophonic mode of speech perception that, although without straightforward consequences for oral communication, has obvious implications for the acquisition of alphabetic writing. Allophonic perception specifically affects the mapping between graphemes and phonemes, contrary to other manifestations of dyslexia, and may be a core deficit.  相似文献   
165.
This study examined the dimensional structure of Templer's Death Anxiety Scale and Abdel-Khalek's Death Obsession Scale. The responses of 289 Spanish students to the Spanish forms of both scales were evaluated by means of a principal components analysis with varimax rotation. Three significant factors were identified: Death Obsession, Cognitive-Affective, and Death Anxiety. The distribution of the factor loadings for the items of both scales on Factors 1 and 3 supported the discriminant validity of the constructs specific to each of the scales, while Factor 2 showed a common component in both scales characterized by cognitive and affective aspects in relation to the idea of death.  相似文献   
166.
The present experiment examined the one-target advantage (OTA) with regard to saccadic eye movements. The OTA, previously found with manual pointing responses, refers to the finding that movements are executed faster when the limb is allowed to stop on the target compared to the situation where it has to proceed and hit a second target. Using an adapted limb movement OTA task, saccades of 5 degrees and 15 degrees were made to (a) a single target (one-target), (b) one target and immediately to another target without a change in direction (two-target-extension), and (c) one target and immediately back to the start location (two-target-reversal). Unlike manual movements, the movement times for the initial saccade in the two-target-extension condition were not prolonged compared to either of the other two conditions. Moreover, this pattern of results was found for both the shorter and longer amplitude saccades. The results indicate that the OTA does not occur in the oculomotor system and therefore is not a general motor control phenomenon.  相似文献   
167.
Prey might assess that risk level estimated in the first encounter with a predator was fixed in subsequent responses, whereas prey using flexible behavior would track short-term changes in risk. The authors examined, in the field, refuge use of Iberian rock lizards (Lacerta monticola) after simulated predator attacks and tested (a) how risk was assessed when multiple sources of risk were present simultaneously, (b) how short-term changes in risk level of successive attacks affected refuge use, and (c) whether the interval between attacks was important, insofar as attacks were considered to be coming from the same or different predators. Results suggest that lizards have a flexible estimate of risk that is based on multiple sources and flexibly dependent on previous estimates.  相似文献   
168.
The authors examined the role of family factors and the course of schizophrenia by carrying out additional assessments and analyses in 2 previously published studies of Mexican American and Anglo American patients and families. The authors found partial support for an attributional model of relapse for families who are low in emotional overinvolvement. Attributions of control, criticism, and warmth together marginally predicted relapse. The data also indicated that for Mexican Americans, family warmth is a significant protective factor, whereas for Anglo Americans, family criticism is a significant risk factor. These findings suggest that the sociocultural context shapes the pathways by which family processes are related to the course of illness. Moreover, the warmth findings suggest that families may contribute to preventing relapse.  相似文献   
169.
Attitude representation theory (C. G. Lord & M. R. Lepper, 1999) explains both attitude-behavior consistency and attitude change with the same principles. When individuals respond evaluatively to an attitude object, they activate and combine assumptions about the attitude object with perceptions of the immediate situation. The assumptions activated can vary across time, even without additional information. Previous research has shown that individuals activate exemplars when answering attitude questions, attitude reports vary with the valence of the assumptions activated, and activating differently liked exemplars reduces attitude-behavior consistency. The present research completed study of the theoretical implications of exemplar stability by showing that individuals with temporally unstable exemplars, whether spontaneous (Experiment 1) or manipulated (Experiments 2 and 3), are more susceptible to subsequent attitude change than are individuals with stable exemplars.  相似文献   
170.
Quality of life of first-degree relatives living in the same household with patients having schizophrenia has not been sufficiently explored. 30 patients with schizophrenia (16 women, 14 men), diagnosed using DSM-IV criteria, 31 of their relatives (15 women, 16 men), and 34 control subjects (21 women, 13 men) were included in the study. The mean age of the patients, their relatives, and the control subects were 39.8 +/- 10.9, 58.1 +/- 12.5 and 37.3 +/- 17.0, respectively. The World Health Oranization Quality of Life-Brief Form was administered to all subjects. Quality of life was worse for the patient group than for their relatives and control subjects, but relatives of the patients and control subjects were not significantly different on Quality of life. Quality of life was negatively correlated with the severity of psychopathology and extrapyramidal side effects induced by antipsychotic drugs in the patients.  相似文献   
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