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871.
We have developed an experimental platform that allows a large number of human participants to interact in real time within a common virtual world. Within this environment, human participants foraged for resources distributed in two spatially separated pools. In addition to varying the relative replenishment rate for the two pools (50-50, 65-35, or 80-20), we manipulated whether the participants could see each other and the entire resource distribution or had their vision restricted to resources at their own location. Two empirical deviations from an optimal distribution of the participants were found. First, the participants were more scattered within a resource pool than the resources were themselves. Second, there was systematic underutilization of the richer pool. For example, the participants distributed themselves 73% and 27% to resource pools that had replenishment rates of 80% and 20%, respectively. In addition, there were oscillations in the harvesting rate of the pools across time, revealed by a Fourier analysis with prominent power near 50 sec per cycle. The suboptimalities and oscillations were more apparent when the locations of the participants and the food were not visible. Individual participant knowledge thus affects the efficiency with which a population of participants harvests resources. 相似文献
872.
Soto-Faraco S Spence C Kingstone A 《Cognitive, affective & behavioral neuroscience》2004,4(2):208-217
Behavioral studies of multisensory integration in motion perception have focused on the particular case of visual and auditory
signals. Here, we addressed a new case: audition and touch. In Experiment 1, we tested the effects of an apparent motion stream
presented in an irrelevant modality (audition or touch) on the perception of apparent motion streams in the other modality
(touch or audition, respectively). We found significant congruency effects (lower performance when the direction of motion
in the irrelevant modality was incongruent with the direction of the target) for the two possible modality combinations. This
congruency effect was asymmetrical, with tactile motion distractors having a stronger influence on auditory motion perception
than vice versa. In Experiment 2, we used auditory motion targets and tactile motion distractors while participants adopted
one of two possible postures: arms uncrossed or arms crossed. The effects of tactile motion on auditory motion judgments were
replicated in the arms-uncrossed posture, but they dissipated in the arms-crossed posture. The implications of these results
are discussed in light of current findings regarding the representation of tactile and auditory space. 相似文献
873.
Robert?G.?CookEmail author Alfred?I.?Geller Guo-Rong?Zhang Ram?Gowda 《Behavior research methods》2004,36(1):101-106
The efficiency of traditional levers and of modern touchscreen technology for training rats on a computerized visual discrimination
was studied in a series of observations. When compared with a lever-based discrimination procedure, the use of touchscreens
supported the faster development of signal tracking behavior and acquisition of a two-stimulus simultaneous visual discrimination.
It did not affect the final level of accuracy. Factors related to spatial proximity of the responses with the stimuli, sign-tracking,
and increased ease of touchscreen motor responses were suggested as possible reasons for the touchscreen training advantage.
This increased efficiency allows large numbers of animals to be tested quickly, a necessary requirement for studies involving
genetic and physiological interventions. 相似文献
874.
Quinn PC 《Psychonomic bulletin & review》2004,11(1):92-97
Quinn and Eimas (1998) reported an asymmetry in the exclusivity of the category representations that young infants form for
humans and nonhuman animals: category representations for nonhuman animal species were found to exclude humans, whereas a
category representation for humans was found to include nonhuman animal species (i.e., cats, horses). The present experiment
utilized the familiarization/novelty-preference procedure with 3- and 4-month-olds to determine the perceptual cues (i.e.,
whole stimulus, head alone, body alone) that provided the basis for this asymmetry. The data revealed the asymmetry to be
observable only with the whole animal stimuli and not when infants were provided with information from just the head or the
body of the exemplars. The results indicate that the incorporation of nonhuman animal species into a category representation
for humans is based on holistic information. 相似文献
875.
876.
Buckle S 《Theoretical medicine and bioethics》2005,26(3):175-194
The paper begins by situating Singer within the British meta-ethical tradition. It sets out the main steps in his argument for utilitarianism as the ‘default setting’ of ethical thought. It argues that Singer’s argument depends on a hierarchy of reasons, such that the ethical viewpoint is understood to be an adaptation – an extension – of a fundamental self-interest. It concludes that the argument fails because it is impossible to get from this starting-point in self-interest to his conception of the ethical point of view. The fundamental problem is its mixing the immiscible: the Humean subordination of reason to interest with the Kantian conception of reason as universal and authoritative. 相似文献
877.
878.
In a first stage of training, participants learned to associate four visual cues (two different colors and two different shapes)
with verbal labels. For Group S, one label was applied to both colors and another to both shapes; for Group D, one label was
applied to one color and one shape, and the other label to the other cues. When subsequently required to learn a task in which
a given motor response was required to one of the colors and one of the shapes, and a different response to the other color
and the other shape, Group D learned more readily than Group S. The task was designed so that the associations formed during
the first stage of training could not generate differential transfer to the second stage. The results are consistent, however,
with the proposal that training in which similar cues are followed by different outcomes will engage a learning process that
boosts the attention paid to features that distinguish these cues. 相似文献
879.
To investigate the contested role of notional number in English subject-verb agreement, we used a sentence completion task
to examine agreement with minimally different subject noun-phrases, such as the gang on the motorcycles and the gang near
the motorcycles. These contrasting phrases biased different notional construals of collective nouns, such as gang, which are
normally ambiguous between plural (distributed) and singular (collected) construals. With subjects biased toward spatial distribution,
such as gang on motorcycles, more plural verbs occurred in speakers’ sentence completions than in sentence completions with
a bias toward spatial collection such as gang near motorcycles. This offers strong evidence regarding both the existence and
the magnitude of notional effects on subject-verb number agreement in English. 相似文献
880.
Coleman SL Brown VR Levine DS Mellgren RL 《Cognitive, affective & behavioral neuroscience》2005,5(4):434-451
This article develops the cognitive—emotional forager (CEF) model, a novel application of a neural network to dynamical processes in foraging behavior. The CEF is based on a neural
network known as the gated dipole, introduced by Grossberg, which is capable of representing short-term affective reactions in a manner similar to Solomon
and Corbit’s (1974) opponent process theory. The model incorporates a trade-off between approach toward food and avoidance
of predation under varying levels of motivation induced by hunger. The results of simulations in a simple patch selection
paradigm, using a lifetime fitness criterion for comparison, indicate that the CEF model is capable of nearly optimal foraging
and outperforms a run-of-luck rule-of-thumb model. Models such as the one presented here can illuminate the underlying cognitive
and motivational components of animal decision making. 相似文献