The Orthogenetic Principle in the Perception of “Forests” and “Trees”?

This study explores possible links between ontogenetic and microgenetic change (Werner, 1948, 1957) in the perception of stimuli with multiple levels of structure. Visual search for targets defined by local versus global structure was examined in observers aged 6, 8, 10, and 22 years. Perceptual access to each level of structure was varied by using pattern elements of same (easy) or opposite contrast polarity (hard); attentional processes were isolated from sensory processes by varying the number of display items. The results showed large improvements with age in search rates for global targets, with search rates for local targets being more constant over age. This pattern held regardless of whether perceptual access to a target was easy or hard. These results support the view that the perception of local and global structure involves different underlying processes.     

Molecular analyses of the effects of d-amphetamine on fixed-interval schedule performances of rats.

A series of doses (0.5 to 2.0 mg/kg) of d-amphetamine was administered to rats whose lever pressing was maintained by fixed-interval 30-s, 60-s, or 120-s schedules of reinforcement by sucrose delivery. Under both saline and d-amphetamine conditions, molecular features of responding were reliably described in terms of the distribution of postreinforcement pauses and local response rate following the onset of responding. Postreinforcement pause always varied from interval to interval but, on average, shortened under the drug. Local response rate (response rate exclusive of pause time) tended to decrease under the drug, and where acceleration occurred within runs of responses, it was reduced by the drug. All of these effects were dose-related. These findings suggest that fixed-interval behavior can be analyzed effectively at a molecular level, and that the effects of d-amphetamine are best described as disruption of temporal discrimination.     

Local preference in concurrent schedules: the effects of reinforcer sequences

We investigated the effects that sequences of reinforcers obtained from the same response key have on local preference in concurrent variable-interval schedules with pigeons as subjects. With an overall reinforcer rate of one every 27 s, on average, reinforcers were scheduled dependently, and the probability that a reinforcer would be arranged on the same alternative as the previous reinforcer was manipulated. Throughout the experiment, the overall reinforcer ratio was 1:1, but across conditions we varied the average lengths of same-key reinforcer sequences by varying this conditional probability from 0 to 1. Thus, in some conditions, reinforcer locations changed frequently, whereas in others there tended to be very long sequences of same-key reinforcers. Although there was a general tendency to stay at the just-reinforced alternative, this tendency was considerably decreased in conditions where same-key reinforcer sequences were short. Some effects of reinforcers are at least partly to be accounted for by their signaling subsequent reinforcer locations.     

Transfer to intermediate forms following concept discrimination by pigeons: chimeras and morphs

Two experiments examined pigeons' generalization to intermediate forms following training of concept discriminations. In Experiment 1, the training stimuli were sets of images of dogs and cats, and the transfer stimuli were head/body chimeras, which humans tend to categorize more readily in terms of the head part rather than the body part. In Experiment 2, the training stimuli were sets of images of heads of dogs and cats, and the intermediate stimuli were computer-generated morphs. In both experiments, pigeons learned the concept discrimination quickly and generalized with some decrement to novel instances of the categories. In both experiments, transfer tests were carried out with intermediate forms generated from both familiar and novel exemplars of the training sets. In Experiment 1, the pigeons' transfer performance, unlike that of human infants exposed to similar stimuli, was best predicted by the body part of the stimulus when the chimeras were formed from familiar exemplars. Spatial frequency analysis of the stimuli showed that the body parts were richer in high spatial frequencies than the head parts, so these data are consistent with the hypothesis that categorization is more dependent on local stimulus features in pigeons than in humans. There was no corresponding trend when the chimeras were formed from novel exemplars. In Experiment 2, when morphs of training stimuli were used, response rates declined smoothly as the proportion of the morph contributed by the positive stimulus fell, although results with morphs of novel stimuli were again less orderly.     

Empirical indistinguishability: From the knowledge structure to the skills

Recent literature has pointed out that the basic local independence model (BLIM) when applied to some specific instances of knowledge structures presents identifiability issues. Furthermore, it has been shown that for such instances the model presents a stronger form of unidentifiability named empirical indistinguishability, which leads to the fact that the existence of certain knowledge states in such structures cannot be empirically tested. In this article the notion of indistinguishability is extended to skill maps and, more generally, to the competence-based knowledge space theory. Theoretical results are provided showing that skill maps can be empirically indistinguishable from one another. The most relevant consequence of this is that for some skills there is no empirical evidence to establish their existence. This result is strictly related to the type of probabilistic model investigated, which is essentially the BLIM. Alternative models may exist or can be developed in knowledge space theory for which this indistinguishability problem disappears.     

Do multicultural experiences facilitate global processing style?

The current research explores whether multicultural experiences facilitate global processing style. We conducted two experiments in which participants were exposed to either a multicultural experience or a monocultural experience. They were required to either perform the Navon letter task (Experiment 1) or search for similarities or differences between two videos (Experiment 2). The experimental results showed that, compared to the participants exposed to a monocultural experience, those exposed to a multicultural experience had faster reaction times to global letters (Experiment 1) and tended to search for similarities (Experiment 2). This indicates that individuals with multicultural experiences facilitate a global processing style. © 2016 John Wiley & Sons Australia, Ltd, Asian Association of Social Psychology and Beijing Normal University     

Local Optima in Mixture Modeling

It is common knowledge that mixture models are prone to arrive at locally optimal solutions. Typically, researchers are directed to utilize several random initializations to ensure that the resulting solution is adequate. However, it is unknown what factors contribute to a large number of local optima and whether these coincide with the factors that reduce the accuracy of a mixture model. A real-data illustration and a series of simulations are presented that examine the effect of a variety of data structures on the propensity of local optima and the classification quality of the resulting solution. We show that there is a moderately strong relationship between a solution that has a high proportion of local optima and one that is poorly classified.     

知觉整体优先性的研究及其进展

知觉的性质是整体的还是分析的 ?这是心理学家们长期争论不休的问题。本世纪 70年代以来 ,一些认知心理学家提出知觉加工的整体优先性假设 ,强调整体在知觉加工中的优先地位。这一假设激发了大量整体 /局部范例的研究。本文综述了这方面的研究 ,分析了它们的理论假设 ,指出了这方面研究的局限以及替代的探讨。     

Configural and local processing of faces in children with Williams syndrome

Three experiments investigated face processing in children with Williams syndrome (WS). In Experiment 1, the ability to discriminate different aspects of faces was compared between WS subjects and a group of children individually matched for chronological age (CA-matches) and another group matched for mental age (MA-matches). In Experiments 2 and 3, the ability to process the local and configural aspects of geometrical patterns and faces was assessed within the same groups of subjects. The results indicated that the WSs' overall performance on face recognition was below that of the CA-matches, but similar to that of the MA-matches. This study revealed in addition that the CA- and MA-matches showed a bias toward a configural mode of face and geometrical shape processing, whereas children with WS did not show any bias. These findings suggest that face processing undergoes an abnormal developmental course in WS.