On simulating non-normal distributions

Six different algorithms to generate widely different non-normal distributions are reviewed. These algorithms are compared in terms of speed, simplicity and generality of the technique. The advantages and disadvantages of using these algorithms are briefly discussed.The author would like to thank an anonymous referee for his comments and suggestions which lead to the inclusion of the section A Comparative Study.     

Choice: Some quantitative relations

Six pigeons responded in fifty-six conditions on a concurrent-chains procedure. Conditions included several with equal initial links and unequal terminal links, several with unequal initial links and equal terminal links, and several with both unequal initial and terminal links. Although the delay-reduction hypothesis accounted well for choice when the initial links were equal (mean deviation of .04), it fit the data poorly when the initial links were unequal (mean deviation of .18). A modification of the delay-reduction hypothesis, replacing the rates of reinforcement with the square roots of these rates, fit the data better than either the unmodified delay-reduction equation or Killeen's (1982) model. The modified delay-reduction equation was also consistent with data from prior studies using concurrent chains. The absolute rates of responding in each terminal link were well described by the same hyperbola (Herrnstein, 1970) that describes response rates on simple interval schedules.     

A study of the classification capabilities of neural networks using unsupervised learning: A comparison withK-means clustering

Several neural networks have been proposed in the general literature for pattern recognition and clustering, but little empirical comparison with traditional methods has been done. The results reported here compare neural networks using Kohonen learning with a traditional clustering method (K-means) in an experimental design using simulated data with known cluster solutions. Two types of neural networks were examined, both of which used unsupervised learning to perform the clustering. One used Kohonen learning with a conscience and the other used Kohonen learning without a conscience mechanism. The performance of these nets was examined with respect to changes in the number of attributes, the number of clusters, and the amount of error in the data. Generally, theK-means procedure had fewer points misclassified while the classification accuracy of neural networks worsened as the number of clusters in the data increased from two to five.Acknowledgements: Sara Dickson, Vidya Nair, and Beth Means assisted with the neural network analyses.     

AN ANALYSIS OF THE REINFORCING PROPERTIES OF HAND MOUTHING

Hand mouthing often has been described as a stereotypic response that is maintained by non-social (automatic) reinforcement; however, data supporting this conclusion can be found in relatively few studies. This series of studies presents an experimental analysis of conditions associated with the maintenance of hand mouthing. In Experiment 1, a functional analysis was conducted for 12 individuals who engaged in chronic hand mouthing to determine whether the behavior is usually maintained independent of social contingencies. Results obtained for 10 subjects were consistent with an automatic reinforcement hypothesis; the remaining 2 subjects' hand mouthing was maintained by social-positive reinforcement. Based on these results, Experiment 2 was designed to identify the specific reinforcing properties of hand mouthing. Each of 4 subjects was provided with a toy that substituted for hand mouthing, and preference for a specific topography of toy manipulation (hand-toy contact or mouth-toy contact) was measured. Results indicated that hand stimulation was the predominant reinforcer for all subjects. Experiment 3 provided an extension of Experiment 2 in that the same responses were measured across a variety of toys presented to each of 5 subjects. Results again indicated that hand stimulation was the predominant reinforcer for all subjects. Implications of these results are discussed with relevance to treatment.     

Mirror neurons and the simulation theory of mind-reading

A new class of visuomotor neuron has been recently discovered in the monkey's premotor cortex: mirror neurons. These neurons respond both when a particular action is performed by the recorded monkey and when the same action, performed by another individual, is observed. Mirror neurons appear to form a cortical system matching observation and execution of goal-related motor actions. Experimental evidence suggests that a similar matching system also exists in humans. What might be the functional role of this matching system? One possible function is to enable an organism to detect certain mental states of observed conspecifics. This function might be part of, or a precursor to, a more general mind-reading ability. Two different accounts of mind-reading have been suggested. According to ‘theory theory', mental states are represented as inferred posits of a naive theory. According to ‘simulation theory', other people's mental states are represented by adopting their perspective: by tracking or matching their states with resonant states of one's own. The activity of mirror neurons, and the fact that observers undergo motor facilitation in the same muscular groups as those utilized by target agents, are findings that accord well with simulation theory but would not be predicted by theory theory.     

偏好反转的兼容性假设的实验研究

本文采用一种新的偏好诱导方法——实物交换方法 ,对偏好反转中的兼容性假设进行实验验证。实验结果支持兼容性假设 ,并发现了一种新的现象 ,即偏好反转的倒置现象。偏好反转与偏好反转的倒置相映成趣 ,为解释风险决策中偏好反转的兼容性假设提供了充足的证据 ,也对风险决策中的纯粹理性提出了更多的挑战。     

GENERALIZED EFFECTS OF A PEER-DELIVERED FIRST AID PROGRAM FOR STUDENTS WITH MODERATE INTELLECTUAL DISABILITIES

Peers with mild intellectual disabilities taught first aid skills to 4 students with moderate intellectual disabilities. A multiple probe design across participants was used to examine the effects of the peer teaching program during an acquisition and a partial sequential withdrawal phase. Generalization assessments were conducted in the participants' homes using novel, randomized simulated injuries. Results suggested that the peer teaching program resulted in acquisition of first aid skills, and the participants' skills generalized to the home, to novel simulated-injury locations, and to new trainers. Additionally, a more detailed analysis of the generalized responding suggested that when given a choice among first aid materials, participants treated burns using large adhesive bandages rather than the materials used in training. Participants also successfully treated injuries when novel instructional cues were used. The findings are discussed with respect to training issues, generalization and maintenance of the acquired skills, and the use of peer tutors with disabilities.     

Searles Kritik am Funktionalismus — Eine Untersuchung des Chinesischzimmers

Searle claims that for a machine to have intentional states it is not sufficient that a formal programme be instantiated. Various types of objections to this claim have been brought up by Searle's critics. Searle's replies to some of these objections are analysed. It turns out that it is more to these objections than Searle wants to make us believe. What is crucial, however, is that Searle's Gedankenexperiment results in a dilemma. At the outset of the dilemma there are two ways of not understanding. According to one of these ways a person (Searle's homunculus) does not understand something without knowing that s/he does not understand. While in the other mode the person knows that s/he doesn't understand. In the first case the inference from facts about the homunculus to facts about the computer is not valid whereas in the second case one would attribute mental states to the computer. Thereby Searle's claim turns out to be unfounded.     

脑内信息加工的不连续性假说

根据阅读眼动的实验资料 ,提出脑内信息加工的时间不连续性假说 ,认为脑内加工相继信息间存在暂时性中断。最近观察到的注意间隙现象为这一假说提供了新的实验证据。     

Public and private self-consciousness as specific psychopathological features

Public self-consciousness (PUBSC) and private self-consciousness (PRISC) represent aspects of dispositional self-directed attention. The aim of the present study was to investigate whether four clinical groups, namely patients with a diagnosis of social phobia, panic disorder, obsessive–compulsive disorder or bulimia nervosa, and normal controls differentiated on the basis of their PUBSC and PRISC scores. Results indicated that both PUBSC and PRISC are extremely elevated in patients with social phobia. Patients with panic disorder and patients with obsessive–compulsive disorder score somewhere between social phobics and normal controls on PUBSC and PRISC scales. Bulimics had significantly higher PUBSC values than both controls and patients with panic disorder, but had lower values than social phobics. Compared to normal controls, bulimics showed no elevated PRISC scores. In addition, contrary to the other groups, PUBSC and PRISC seem to be unrelated in bulimics. Thus, PUBSC and PRISC appear to be specific psychopathological features for German females when comparing groups with different mental disorders and normal controls.