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1.

The concept of being in a position to know is an increasingly popular member of the epistemologist’s toolkit. Some have used it as a basis for an account of propositional justification. Others, following Timothy Williamson, have used it as a vehicle for articulating interesting luminosity and anti-luminosity theses. It is tempting to think that while knowledge itself does not obey any closure principles, being in a position to know does. For example, if one knows both p and ‘If p then q’, but one dies or gets distracted before being able to perform a modus ponens on these items of knowledge and for that reason one does not know q, one is still plausibly in a position to know q. It is also tempting to suppose that, while one does not know all logical truths, one is nevertheless in a position to know every logical truth. Putting these temptations together, we get the view that being in a position to know has a normal modal logic. A recent literature has begun to investigate whether it is a good idea to give in to these twin temptations—in particular the first one. That literature assumes very naturally that one is in a position to know everything one knows and that one is not in a position to know things that one cannot know. It has succeeded in showing that, given the modest closure condition that knowledge is closed under conjunction elimination (or ‘distributes over conjunction’), being a position to know cannot satisfy the so-called K axiom (closure of being in a position to know under modus ponens) of normal modal logics. In this paper, we explore the question of the normality of the logic of being in a position to know in a more far-reaching and systematic way. Assuming that being in a position to know entails the possibility of knowing and that knowing entails being in a position to know, we can demonstrate radical failures of normality without assuming any closure principles at all for knowledge. (However, as we will indicate, we get further problems if we assume that knowledge is closed under conjunction introduction.) Moreover, the failure of normality cannot be laid at the door of the K axiom for knowledge, since the standard principle NEC of necessitation also fails for being in a position to know. After laying out and explaining our results, we briefly survey the coherent options that remain.

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2.
Using a Piagétan perspective, this study investigated the ways in which elementary school children perceive changes in the size of a televised image (in this case, a candy bar). The findings suggest that younger children perceive changes in image size from a medium shot to a close-up as changes in the object itself. Children's responses to changes in the televised image parallel their responses to traditional conservation tasks, but conservation of televised images occurs at a later age. In addition, children appear to use different cognitive skills to interpret how a zoom or a cut transforms the size of a televised image. When a zoom is used, children more readily perceive the object as “growing larger.”  相似文献   

3.
4.
Belief in a just world has been linked to high interpersonal trust and less suspicion of deception. We therefore predicted people with a strong dispositional belief in a just world to have low motivation to accurately detect deception. Accordingly, we hypothesized such a belief to be negatively related to accuracy in deception detection. Furthermore, research on Terror Management Theory has indicated that culturally shared values, such as justice, become more important after mortality salience. Thus, we assumed engaging in justice concerns after a death threat is especially relevant for people with a strong belief in a just world, and further, that accurate deception detection is a matter of justice. Based on this reasoning, we expected people with a strong belief in a just world to have an increased motivation to accurately detect deception after mortality salience. Consequently, we hypothesized dispositional differences in belief in a just world to be unrelated to accuracy in deception detection after mortality salience. In line with these predictions, our study revealed that participants with a strong (vs. weak) belief in a just world were worse in deception detection unless they had first been reminded of their mortality.  相似文献   

5.
Two experiments were carried out in order to investigate how the linguistic context (in the form of a sentence) facilitates the interpretation of unambiguous words. Experiment I established that if a sentential context as a whole is sufficient to evoke an inference that calls to mind a particular aspect of a word's meaning, the presence of a verb with appropriate selectional restrictions does not enhance the process. Experiment II showed that when no other cues are provided within a sentence, both verbs and adjectives are effective in enhancing a specific aspect of the meaning of a word. These findings were taken to support the hypothesis that in understanding a sentence, people instantiate particular aspects of the meanings of words in order to construct specific interpretations, and linguistic context guides this process of selection.  相似文献   

6.

We present a kinetic model to explain irradiation-induced phenomena in graphite up to a high dose of amorphization. We attribute the origin of amorphization to the accumulation of dislocation dipoles instead of a disordered region assumed in a previous model by Niwase. Calculated results for the change in a sample dimension up to amorphization and the Raman intensity ratio in a low-damage range compare favourably with the experimental results, revealing the existence of a barrier inhibiting the mutual annihilation of an interstitial and a vacancy.  相似文献   

7.
Three experiments used rats as subjects and the conditioned emotional response (CER) paradigm to examine the effect of pre-exposure to a compound stimulus on the extent of latent inhibition to an element of that compound. In Experiment 1a a group of rats exposed to a compound that comprised a tone and a click exhibited less latent inhibition to the tone than did a group that had received pre-exposure to the tone in isolation. Experiment 1b showed that pre-exposure to the tone/click compound also resulted in an attenuation of latent inhibition to the click relative to a group that was pre-exposed to the click in isolation. Experiment 2 demonstrated that latent inhibition to the tone was left intact following pre-exposure to the tone in compound with a light. This pattern of results seems to be most plausibly explained in terms of the presence and absence of generalization decrement following compound pre-exposure.  相似文献   

8.
The anterior cingulate cortex (ACC) plays a critical role in stimulus-reinforcement learning and reward-guided selection of actions. Here we conducted a series of experiments to further elucidate the role of the ACC in instrumental behavior involving effort-based decision-making and instrumental learning guided by reward-predictive stimuli. In Experiment 1, rats were trained on a cost-benefit T-maze task in which they could either choose to climb a barrier to obtain a high reward (four pellets) in one arm or a low reward (two pellets) in the other with no barrier present. In line with previous studies, our data reveal that rats with quinolinic acid lesions of the ACC selected the response involving less work and smaller reward. Experiment 2 demonstrates that breaking points of instrumental performance under a progressive ratio schedule were similar in sham-lesioned and ACC-lesioned rats. Thus, lesions of the ACC did not interfere with the effort a rat is willing to expend to obtain a specific reward in this test. In a subsequent task, we examined effort-based decision-making in a lever-press task where rats had the choice between pressing a lever to receive preferred food pellets under a progressive ratio schedule, or free feeding on a less preferred food, i.e. lab chow. Results show that sham- and ACC-lesioned animals had similar breaking points and ingested comparable amounts of less-preferred food. Together, the results of Experiment 1 and 2 suggest that the ACC plays a role in evaluating how much effort to expend for reward; however, the ACC is not necessary in all situations requiring an assessment of costs and benefits. In Experiment 3 we investigated learning and reversal learning of instrumental responses guided by reward predictive stimuli. A reaction time (RT) task demanding conditioned lever release was used in which the upcoming reward magnitude (five vs. one food pellet) was signalled in advance by discriminative visual stimuli. Results revealed that rats with ACC lesions were able to discriminate reward magnitude-predictive stimuli and to adapt instrumental behavior to reversed stimulus-reward magnitude contingencies. Thus, in a simple discrimination task as used here, the ACC appears not to be required to discriminate reward magnitude-predictive stimuli and to use the learned significance of the stimuli to guide instrumental behavior.  相似文献   

9.
Within the last few years, considerable attention has been devoted to the possibility that the amelioration of stuttering in many novel speaking conditions is a function of vocal changes with or without accompanying modifications in prosodic expression. These formulations have made reference primarily to conditions in which stutterers were induced into one or another novel speech pattern by an external stimulus such as masking noise, a rhythmic cue, or by instructions to sing, or read in unison with another speaker. In contrast, far less attention has been paid to other ameliorative conditions that lack a novel external stimulus or special instructions that direct the stutterer to speak in some unique manner. Speaking or reading to a child is an example of this latter type of condition. The present study was conducted to see if nine adult stutterers and a matched group of nonstutterers would evince vocal changes as they read aloud to another adult, a child, and a child and adult together. There was also a fourth control condition wherein the subjects read to one of the experimenters. Dependent measures of disfluency and stuttering, fundamental frequency, fundamental frequency deviation, fluent reading rate, and peak vocal sound pressure level were made and treated statistically. The major findings of this study indicated that, relative to the control condition, both subject groups exhibited several vocal changes when reading to a child alone and to a child and adult together. In addition, the stutterers experienced a reduction in disfluency, but only when reading to the child alone. The normal speakers exhibited too few disfluencies in the control condition for any meaningful change to occur in that dependent variable. The fact that the stutterers evinced vocal changes in both experimental conditions but a significant drop in disfluency in just one bears importantly on hypotheses that emphasize vocal changes in conditions that ameliorate stuttering.  相似文献   

10.
In this study, the authors used a dual-task flanker paradigm to investigate the degree to which flankers are coprocessed with the target as a function of whether flankers have to be used as stimuli for a second task. A series of experiments, in which performance in dual tasks was compared with that in single tasks, revealed that participants had a strong tendency to coprocess flankers to a large degree in dual tasks, even if this impaired performance. Coprocessing of flankers was reduced only when totally irrelevant flankers were presented at the beginning of a trial or single tasks were performed on the great majority of trials within a block. The results suggest that it was demanding to process targets and flankers serially when both had to be used for a dual task. As a consequence, target and flankers were processed in parallel, even if this was nonoptimal for target selection.  相似文献   

11.
Recent scholarship has shown chattel slavery in the Roman Empire to have been a deeply oppressive experience. Paul knew that reality well and used the language of slavery metaphorically in Galatians and Romans to describe humanity's subjection to sin. However, he also made a remarkable shift in his use of the metaphor to indicate a new form of slavery to God which brings freedom, thereby subverting conventional ways of understanding slavery. In Paul's sense, slavery is an ineluctable part of human existence in which we have a choice of being a slave to sin or a slave to God. Becoming a slave means giving up all claims to status and relates to Christ's humble‐mindedness in Philippians. The slave is also a model of faithfulness, comparable with God's faithfulness to Israel and Christ's faithfulness to the mission given him by his Father. Being a slave (in Paul's sense) is at the heart of the Christian life, exemplifying the ‘obedience of faith’, for it is through this faithfulness that we become righteous.  相似文献   

12.
Many decisions related to cigarette smoking require people in an affectively neutral, or "cold," state to predict how they will feel or behave when in a craving, or "hot," state. Research in other domains has revealed that individuals in cold states often underestimate the impact of being in a hot state on their own future behavior. In a study testing whether this is true of cigarette craving, 98 smokers were assigned to one of three conditions: hot (during a high-craving first session, they made predictions about a high-craving state in a second session), cold (during a low-craving first session, they made predictions about a high-craving state in a second session), and comparison (they experienced a high-craving session only). As predicted, in contrast to smokers in the hot group, smokers in the cold group underpredicted the value they would place on smoking during the second session. Results support the existence of a cold-to-hot empathy gap in smokers and help to explain diverse aspects of tobacco addiction.  相似文献   

13.
Abstract— Becoming a proficient symbol user is a universal developmental last in the first years of life, but delecting and mentally representing symbolic relations can be quite challenging for young children To test the extent to which symbolic reasoning per se is problematic, we compared the performance of 2-year-olds in symbolic and nonsymbolic versions of a search task. The children had to use their knowledge of the location of a toy hidden in a room to draw an inference about where to find a miniature toy in a scale model of the room (and vice versa) Children in the nonsymbolic condition believed a shrinking machine had caused the room to become the model They were much more successful than children in the symbolic condition, for whom the model served as a symbol of the room The symbol understanding and use.  相似文献   

14.
Spatial familiarization consists of a decrease in the exploratory activity over time after exposure to a place. Here, we show that a 30-min exposure to an open field led to a pronounced decrease in the exploratory behavior of rats, generating context familiarity. This behavioral output is associated with a selective decrease in hippocampal PKMzeta levels. A short 5-min exposure did not induce spatial familiarity or a decrease in PKMzeta, while inactivation of hippocampal PKMzeta by the specific inhibitor ZIP was sufficient to induce spatial familiarity, suggesting that the decrease in PKMzeta is involved in setting a given context as a familiar place.  相似文献   

15.
It was hypothesized that 6-month-old infants may be able to use indirect landmarks to locate a goal if (a) the landmarks are sufficiently distinctive and (b) the goal location is between landmarks, rather than on the opposite side of the space as was used in earlier research. Six-month-old infants were tested in a peekaboo paradigm in which they had to turn to a target location after displacement to a novel position. Infants looked to the goal location significantly more in a beacon and an indirect landmarks condition relative to a control and a single landmark condition. These results are discussed in terms of current theories of spatial development.  相似文献   

16.
Six experiments using habituation of exploratory behavior tested whether disoriented rats foraging in a large arena encode the shapes of arrays of objects. Rats did not respond to changes in position of a single object, but they responded to a change in object color and to a change in position of 1 object in a square array, as in previous research (e.g., C. Thinus-Blanc et al., 1987). Rats also responded to an expansion of a square array, suggesting that they encoded sets of interobject distances rather than overall shape. In Experiments 4-6, rats did not respond to changes in sense of a triangular array that maintained interobject distances and angles. Shapes of object arrays are encoded differently from shapes of enclosures.  相似文献   

17.
Two experiments are reported which examine children's ability to use referential context when making syntactic choices in language production and comprehension. In a recent on-line study of auditory comprehension, Trueswell, Sekerina, Hill, and Logrip (1999) examined children's and adults' abilities to resolve temporary syntactic ambiguities involving prepositional phrases (e.g., “Put the frog on the napkin into ¨”). Although adults and older children used the referential context to guide their initial analysis (pursuing a destination interpretation in a one-frog context and a modifier interpretation in a two-frog context), 4 to 5-year olds' initial and ultimate analysis was one of destination, regardless of context. The present studies examined whether these differences were attributable to the comprehension process itself or to other sources, such as possible differences in how children perceive the scene and referential situation. In both experiments, children were given a language generation task designed to elicit and test children's ability to refer to a member of a set through restrictive modification. This task was immediately followed by the “put” comprehension task. The findings showed that, in response to a question about a member of a set (e.g., “Which frog went to Mrs. Squid's house?”), 4- to 5-year-olds frequently produced a definite NP with a restrictive prepositional modifier (e.g., “The one on the napkin”). These same children, however, continued to misanalyze put instructions, showing a strong avoidance of restrictive modification during comprehension. Experiment 2 showed that an increase in the salience of the platforms that distinguished the two referents increased overall performance, but still showed the strong asymmetry between production and comprehension. Eye movements were also recorded in Experiment 2, revealing on-line parsing patterns similar to Trueswell et al.: an initial preference for a destination analysis and a failure to revise early referential commitments. These experiments indicate that child–adult differences in parsing preferences arise, in part, from developmental changes in the comprehension process itself and not from a general insensitivity to referential properties of the scene. The findings are consistent with a probabilistic model for uncovering the structure of the input during comprehension, in which more reliable linguistic and discourse-related cues are learned first, followed by a gradually developing ability to take into account other more uncertain (or more difficult to learn) cues to structure.  相似文献   

18.
A scenario study was performed to investigate whether people in the street would be less likely to respond positively to a stranger's request for a small favor if the stranger wore a T-shirt bearing a progay slogan. One hundred and eighteen female and 112 male participants were each presented with six scenarios, all of which asked them to imagine being approached by a person requesting change for a banknote. The dependent variable in the study was the participant's judgment, on a 7-point scale, of how likely he or she would be to help. Five of the scenarios were included as distractors. In the critical scenario, the requester was described as wearing a plain T-shirt or one with either a progay or a control slogan printed on it. The male participants in the progay condition showed a significantly lower level of help than those in either of the control groups. The antigay pattern, however, was not obtained in the responses of the female participants. The results are discussed with reference to other findings in the literature, and their implications for people's responses to progay persons in everyday life are considered.  相似文献   

19.
This paper takes key insights from social psychologists and interrogates them as methodological tools for historians, applying these theories to a large-scale uprising that occurred in southern England in 1549. In a social order based on notions of paternalism and deference, a diverse band of rebels were able to forge an alliance strong enough to pose a serious threat to local authorities in Norwich. Social psychological approaches to collective memory and evolving social representations are deployed to highlight contested memories of rebellion as central to Tudor state formation, and to understand how a rebel group with many competing interests was able to sustain their alliance. I argue that the imperative to understand individual behaviour in a collective context illuminates the way that this group could form a vision of the world which contradicted deferential social ideals without ranging themselves against central government. The article also suggests ways in which historical approaches can inform social psychological concepts.  相似文献   

20.
This study adds to tests of the construct validity of stigma consciousness by asking if people high in stigma consciousness demonstrate a greater tendency than people low in stigma consciousness to make attributions to discrimination. In a study that approached this question from both an individual difference and a situational perspective, women high or low in stigma consciousness made attributions for a negative evaluation, ostensibly written by a male peer. Under control conditions, women low in trait stigma consciousness demonstrated less of a tendency to make attributions to discrimination than women high in trait stigma consciousness. When they experienced a situationally induced increase in stigma consciousness, however, participants low in trait stigma consciousness demonstrated just as great a tendency to make attributions to discrimination as their high stigma conscious counterparts. The results provide further validation for the stigma consciousness construct, and raise questions about who benefits from attributions to discrimination.  相似文献   

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