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931.
    
by William Irons 《Zygon》2009,44(2):347-354
This essay critiques dual-inheritance theory as presented in Peter Richerson and Robert Boyd's book Not by Genes Alone: How Culture Transformed Human Evolution (2005). The theory states that culture became prominent in human evolution because it allowed relatively rapid adaptation to changing environments by means of imitation. Imitating the behavior of other members of one's community produces adaptive behaviors more readily than either genetic evolution or individual learning. Imitation follows a number of patterns: imitating high-status individuals, imitating the most common forms of behavior, imitating behaviors perceived to be the most effective solutions to various problems relevant to survival. This process combined with occasional innovations in behavior lead to a process of cultural evolution involving populations of cultural variants. Different local human populations were associated with different local populations of cultural variants, and both the human and the cultural populations evolved over time. Human evolution cannot be understood without taking into account these parallel processes of genetic and cultural evolution. Not by Genes Alone traces the implication of dual-inheritance theory for understanding human evolution and refers to various bodies of evidence relevant to the theory.  相似文献   
932.
    
The contribution of past experiences to concurrent resurgence was investigated in three experiments. In Experiment 1, resurgence was related to the length of reinforcement history as well as the reinforcement schedule that previously maintained responding. Specifically, more resurgence occurred when key pecks had been reinforced on a variable-interval 1-min schedule than a variable-interval 6-min schedule, but this effect may have been due either to the differential reinforcement rates or differential response rates under the two schedules. When reinforcement rates were similar (Experiment 2), there was more resurgence of high-rate than low-rate responding. When response rates were similar (Experiment 3), resurgence was not related systematically to prior reinforcement rates. Taken together, these three experimental tests of concurrent resurgence illustrate that prior response rates are better predictors of resurgence than are prior reinforcement rates.  相似文献   
933.
    
Five adolescents with autism, 5 adult control participants, and 4 child controls received rewards for varying their sequences of responses while playing a computer game. In preceding and following phases, rewards were provided at approximately the same rate but were independent of variability. The most important finding was that, when reinforced, variability increased significantly in all groups. Reinforced variability could provide the necessary behavioral substrate for individuals with autism to learn new responses.  相似文献   
934.
    
This study examined the effects of noncontingent reinforcement (NCR) with and without extinction on problem behavior and stimulus engagement (consumption of reinforcement) of 4 participants. Reductions in problem behavior using NCR have frequently been attributed to both satiation of the reinforcer and extinction. In the current study, aspects of the NCR treatment effects were difficult to explain based solely on either a satiation or an extinction account. Specifically, it was found that stimulus engagement remained high throughout the NCR treatment analysis, and that problem behavior was reduced to near-zero levels during NCR without extinction. The implications of these findings are discussed with respect to the satiation and extinction hypotheses frequently described in the applied literature. Findings from basic studies examining the effects of response-independent schedules are presented, and are used as the basis for a matching theory account of NCR-related effects. It is proposed that reductions in problem behavior observed during NCR interventions may be a function of the availability of alternative sources of reinforcement.  相似文献   
935.
936.
    
To develop a mechanistic bacterial dose–response model, based on the concept of Key Events Dose–Response Framework (KEDRF), this study aimed to investigate the invasion of intestinal model cells (Caco-2) by Salmonella Typhimurium and Listeria monocytogenes and described the behaviour of both pathogens as a mathematical model using Bayesian inference. Monolayer-cultured Caco-2 cells (approximately 105 cells) were co-cultured with various concentrations (103–107 colony forming unit [CFU] ml−1) of Salm. Typhimurium and L. monocytogenes for up to 9 h to investigate the invasion of the pathogens into the Caco-2 cells. While an exposure of ≥103 CFU ml−1 of Salm. Typhimurium initiated the invasion of Caco-2 cells within 3 h, much less exposure (102 CFU ml−1) of L. monocytogenes was sufficient for invasion within the same period. Furthermore, while the maximum number of invading Salm. Typhimurium cells reached by approximately 103 CFU cm−2 for 6-h exposure, the invading maximum numbers of L. monocytogenes cells increased by approximately 106 CFU cm−2 for the same exposure period. The invasion kinetics of both the pathogens was successfully described as an asymptotic exponential mathematical model using Bayesian inference. The developed pathogen invasion model allowed the estimation of probability of Salm. Typhimurium and L. monocytogenes infection, based on the physiological natures of digestion process, which was comparable to the published dose–response relationship. The invasion models developed in the present study will play a key role in the development of an alternative pathogen dose–response model based on KEDRF concept.  相似文献   
937.
    
Deficits in working memory (WM) and processing speed (PS) are thought to undermine other cognitive functions in de novo Parkinson's disease (dnPD). However, these interrelationships are only partially understood. This study investigated whether there are stronger relationships between verbal WM and verbal episodic memory encoding and retrieval, whether verbal WM and PS have a greater influence on other aspects of cognitive functioning, and whether the overall strength of interrelationships among several cognitive functions differs in dnPD compared to health. Data for 198 healthy controls (HCs) and 293 dnPD patients were analysed. Participants completed a neuropsychological battery probing verbal WM, PS, verbal episodic memory, semantic memory, language and visuospatial functioning. Deficit analysis, network modelling and graph theory were combined to compare the groups. Results suggested that verbal WM performance, while slightly impaired, was more strongly associated with measures of verbal episodic memory encoding and retrieval, as well as other measured cognitive functions in the dnPD network model compared to the HC network model. PS task performance was impaired and more strongly associated with other neuropsychological task scores in the dnPD model. Associations among task scores were stronger overall in the dnPD model. Together, these results provide further evidence that WM and PS are important influences on the other aspects of cognitive functioning measured in this study in dnPD. Moreover, they provide novel evidence that verbal WM and PS might bear greater influence on the other measured cognitive functions and that these functions are more strongly intertwined in dnPD compared to health.  相似文献   
938.
    
Although it is generally accepted that ageing is associated with recollection impairments, there is considerable disagreement surrounding how healthy ageing influences familiarity-based recognition. One factor that might contribute to the mixed findings regarding age differences in familiarity is the estimation method used to quantify the two mnemonic processes. Here, this issue is examined by having a group of older adults (N = 39) between 40 and 81 years of age complete remember/know (RK), receiver-operating characteristic (ROC) and process dissociation (PD) recognition tests. Estimates of recollection, but not familiarity, showed a significant negative correlation with chronological age. Inconsistent with previous findings, the estimation method did not moderate the relationship between age and estimates of recollection and familiarity. In a final analysis, recollection and familiarity were estimated as latent factors in a confirmatory factor analysis that modelled the covariance between measures of free recall and recognition, and the results converged with the results from the RK, PD and ROC tasks. These results are consistent with the hypothesis that episodic memory declines in older adults are primary driven by recollection deficits, and also suggest that the estimation method plays little to no role in age-related decreases in familiarity.  相似文献   
939.
940.
    
The error theory is a metaethical theory that maintains that normative judgments are beliefs that ascribe normative properties, and that these properties do not exist. In a recent paper, Bart Streumer argues that it is impossible to fully believe the error theory. Surprisingly, he claims that this is not a problem for the error theorist: even if we can’t fully believe the error theory, the good news is that we can still come close to believing the error theory. In this paper I show that Streumer’s arguments fail. First, I lay out Streumer’s argument for why we can’t believe the error theory. Then, I argue against the unbelievability of the error theory. Finally, I show that Streumer’s positive proposal that we can come close to believing the error theory is actually undermined by his own argument for why we can’t believe the error theory.  相似文献   
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