共查询到20条相似文献,搜索用时 31 毫秒
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A Levitt P W Jusczyk J Murray G Carden 《Journal of experimental psychology. Human perception and performance》1988,14(3):361-368
We investigated 2-month-old infants' perception of a subset of highly confusable English fricatives. In Experiment 1, infants discriminated modified natural tokens of the voiceless fricative pair [fa]/[oa] but only when the syllables included their frication noises. They also discriminated the voiced pair [va]/[oa] both with and without fricative noises. These results parallel those found with adults by Carden, Levitt, Jusczyk, and Walley (1981). In Experiment 2 [f] and [o] noises were appended to [a], and the same [f] noise was appended to the previously indiscriminable fricationless versions of [fa] and [oa]. Infants discriminated both pairs of stimuli, indicating that (a) the frication is a sufficient cue for [fa]/[oa] discrimination and that (b) it provides a context for discriminating the [f] and [o] formant transitions. We conclude that infants' perception of labiodental/interdental fricative contrasts show evidence of context effects similar to those observed with adults. 相似文献
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D. C. Matthew 《South African Journal of Philosophy》2017,36(4):495-504
In counterfactual cases of discrimination, an agent would have treated someone worse had circumstances been different such that instead of being a member of her actual group, she was a member of some other group. The case for considering such cases to be genuine cases of discrimination is bolstered by the fact that we are inclined to say that cases where an agent would have treated someone better had she been a member of another group are discriminatory. But I argue that the cases are relevantly different: in one kind of case, but not the other, a person is harmed. I then consider and reject a number of objections to this suggestion. 相似文献
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Thresholds for vibrotactile discrimination of pulse interval were determined for pulse frequencies between 1 and 384 Hz. The results point to a temporal resolution significantly more accurate than that demonstrated in earlier studies. Although touch as a vibratory sensor is in general much inferior to audition, the present results show a striking resemblance to those obtained on auditory pitch. The neurophysiological implications for the tactile as well as for the auditory system are discussed. 相似文献
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M K Kaiser 《Perception & psychophysics》1990,47(2):149-156
Three experiments were designed to investigate naive observers' abilities at discriminating the rotational velocities of two simultaneously viewed objects. In Experiment 1, rotations could occur about parallel or orthogonal axes, with initial orientations in phase or out of phase, and (for parallel rotational axes) in the same or opposite direction. Differential thresholds were approximately 10%. In Experiment 2, stimulus objects differed in the number of faces revealed in rotation (three vs. four). Observers' response curves had no greater spread, but their PSEs (points of subjective equality) were shifted such that there was a partial compensation for faces revealed per unit time. In both Experiment 1 and Experiment 2, performance was consistent across rotational axis and directional conditions. In Experiment 3, the effect of object size was examined, in order to determine the extent to which angular velocity judgments are influenced by the tangential velocity of the faces. When the comparison cube's edges were half the length of the standard's, PSEs were elevated 18.5%. Taken together, these data suggest that observers are able to discriminate angular velocities with a competence near that for linear velocities. However, perceived angular rate is influenced by structural aspects of the stimuli. 相似文献
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S O Cole 《Behavioral and neural biology》1983,37(2):344-349
Chlordiazepoxide (5.0 and 10.0 mg/kg but not 2.5 mg/kg) administered on 10 successive sessions, significantly impaired the reinforcement-cued discrimination performance of male Sprague-Dawley rats. On three postdrug (saline) recovery sessions, groups previously treated with the drug demonstrated good recovery in discrimination performance. An analysis of response components indicated that the discrimination impairment was due to less inhibition of responding during "no-go" phases of the task by the drugged than control animals. While changes in responding during reinforcement phases may also contribute to the performance of drugged animals, no clear pattern emerges from the present study. 相似文献
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Data are presented which support a mathematical model for visual movement perception. An observer’s ability to judge the relative position of two successively presented points of light in an otherwise dark room is shown to diminish as the inter-stimulus interval is increased. However, a measure of visual position memory appears to remain invariant a5 this interval is varied. Neither the degree of head stabilization nor whether viewing is monocular or binocular appreciably alters this measure. 相似文献
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F A Logan 《Journal of experimental psychology. General》1966,71(4):616-618
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Observers with good stereoacuity judged which eye received sine-wave grating patterns in a two-category forced-choice procedure. Large individual differences were found, but for most observers reliable discrimination was achieved at low spatial frequencies. No observer could perform the task above chance levels at high spatial frequencies. Discrimination was unaffected by retinal location, grating orientation, grating contrast, stimulus duration, or practice with feedback. Among observers who could perform the task, the following results were obtained: (1) Introduction of high spatial frequency components did not interfere with performance so long as a low spatial frequency component was present. (2) When gratings of low equal spatial frequency were presented to both eyes simultaneously at different contrast levels, observers could identify which eye received the higher contrast. (3) At low spatial frequencies, observers could distinguish monocular from binocular presentation. (4) Temporal frequency variations (counterphase flicker) influenced performance for some observers. Binocular summation and interocular transfer were unaffected by the spatial frequency variations which modulate utrocular discrimination. A new procedure for measuring stereopsis was developed which made possible comparison of utrocular discrimination with stereopsis at specific spatial frequencies. Stereopsis appeared mildly affected by spatial frequency. 相似文献
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Effect of prior Pavlovian discrimination training upon learning an operant discrimination 总被引:1,自引:1,他引:0
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The effect of Pavlovian discrimination training with two stimuli upon subsequent learning of an operant discrimination involving those stimuli was studied. After preliminary lever press training, the lever was removed and thirsty rats received noncontingent pairings between S1 (a tone or a clicker) and water reinforcements, whereas S2 (a clicker or a tone) occurred always without reinforcement. This procedure presumably established S1 as a positive CS for respondent behavior, whereas S2 was established as an inhibitory CS. Following this training, the lever was reintroduced and the rats were trained on an operant (lever pressing) discrimination involving S1 and S2. For the Consistent Ss, S1 was the SD and S2 the SΔ in the operant discrimination; for the Reversed Ss, S2 served as SD and S1 as SΔ. The Consistent Ss learned the operant discrimination significantly faster than did the Reversed Ss. The result emphasizes the importance of respondents, conditioned to SD and SΔ, which modulate operant performance to these stimuli. 相似文献
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《Trends in cognitive sciences》1997,1(2):48
Summaries of recently published papers of interest to cognitive scientists. Readers who would like to contribute to this section, by identifying appropriate papers and writing short summaries, should contact the Editor. 相似文献
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William Martens Randolph Blake Michael Sloane Robert H. Cormack 《Attention, perception & psychophysics》1981,30(6):521-532
Utrocular discrimination, the ability to judge which eye has received monocular stimulation, was studied under conditions designed to reduce the salience of the cue mediating this discrimination. In one series of experiments, these conditions involved reducing the likelihood of motor command signals, overwhelming the motor command centers, and triggering motor command signals for both eyes. Those results indicate that utrocular discrimination is not mediated by ocular movements or command signals. In a second series of experiments, a visual masking paradigrn was used. A monocular test grating appeared superimposed upon a background of binocular masking noise, which was presented either simultaneously with the target or at some interval preceding or following the target (asynchronous masking). When presented simultaneously, the binocular masking noise interfered with utrocular performance, but only when the noise contained spatial frequencies near the test frequency. Masking functions obtained under conditions of asynchronous masking indicated that the time course of the forward and backward masking changed with spatial frequency. Finally, a sustained masking pattern that was ineffective in reducing utrocular performance could be made effective by pulsing the mask simultaneously with the target. Taken together, these results implicate a transient response to the target onset as a critical factor in generating the cue for successful utrocular discrimination. This conclusion may account for the fact that utrocular discrimination falls off for normal observers as the spatial frequency of the target grating increases above 4 cycles/deg. 相似文献
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Subjects learned paired associate fists in which word triads were paired with nouns to a partial criterion; they were then given both an immediate and a 1-week delayed recognition test for discrimination among the triads and a cued recall test. Recall after 1 week was slightly poorer than that occurring immediately, but it was unaffected by various patterns of element identity among the triads. Discrimination improved somewhat over the 1-week interval. Further experiments showed that the immediate test was responsible for both reducing forgetting and improving discrimination, but both effects were independent of identity structure. Forgetting cannot be attributed to loss of differentiation of cues. 相似文献
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Michelle O'Riordan Kate Plaisted 《The Quarterly Journal of Experimental Psychology Section A: Human Experimental Psychology》2001,54(4):961-979
Children with autism are superior to typically developing children at visual search tasks (O'Riordan, Plaisted, Driver, & Baron-Cohen, in press; Plaisted, O'Riordan, & Baron-Cohen, l998b). This study investigates the reasons for this phenomenon. The performance of children with autism and of typically developing children was compared on a series of visual search tasks to investigate two related problems. The first issue was whether the critical determinant of search rate in children is the discriminability of the display items, as it is in normal adults. The second question investigated was whether the superior performance of individuals with autism on visual search tasks is due to an enhanced ability to discriminate between display items. The results demonstrated that discriminability is the rate-determining factor for children with and without autism, replicating earlier findings with normal adults, and that children with autism have an enhanced ability to discriminate between display items. Thus, it seems that an enhanced ability to discriminate between display items underlies superior visual search in autism. 相似文献
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KASPER Lippert-rasmussen 《Ethical Theory and Moral Practice》2006,9(2):167-185
The most blatant forms of discrimination are morally outrageous and very obviously so; but the nature and boundaries of discrimination are more controversial, and it is not clear whether all forms of discrimination are morally bad; nor is it clear why objectionable cases of discrimination are bad. In this paper I address these issues. First, I offer a taxonomy of discrimination. I then argue that discrimination is bad, when it is, because it harms people. Finally, I criticize a rival, disrespect-based account according to which discrimination is bad regardless of whether it causes harm. 相似文献
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Bornstein’s hypothesis that there is a loss of color discrimination in tropical areas was not supported in earlier research
in the Cook Islands. Using a more sensitive color vision test (the Farnsworth-Munsell 100-Hue Test), a loss of color discrimination
in the red-purple and blue-green regions of the spectrum was found. The lack of sex differences in this color discrimination
loss supports a physiological rather than a genetic explanation of the observed decrement. 相似文献