Properties of changing patterns evoking visually perceived oscillation

The aim of this study was to identify some properties of changing proximal stimulus patterns which favor perceived oscillation. By using artificially generated stimulus patterns, it was found that the amount of changes associated with a certain direction of rotation should be small and the rate of these changes low if perceived oscillation was to appear. Great or swift changes were utilized by the visual system to determine perceived direction of rotation, and oscillation was not then reported. It was further found that patterns lacking straight edges perpendicular to the axis of rotation, or with this axis displaced from the middle of the pattern, and patterns with a gradient of texture density were perceived to oscillate more than similar patterns without these properties. Perceived oscillation of ellipses was discussed, and it was concluded that perceived oscillation was a consequence of perceived orientation, which is determined by stimulus properties.     

The effects of cue reliability on infants' manual search.

Nine-month-old babies were presented a manual search problem in which toys were hidden in one of two containers, and then the containers were transposed. Over a series of training trials either two, one, or no cues were perfectly correlated with the location of the toy. The infants' first searches became more accurate over training trials in conditions with consistent container and/or position cues. In the final training trial block search performance was best with two cues, intermediate with one cue, and least accurate in the no-cue condition. In a subsequent reversal procedure, in which the toy was placed in the previously unused hiding place, the number of correct first searches also differed according to the nature of cues available across hidings. The implications for learning the concept of object permanence are discussed.     

Direct comparison of auditory implicit memory tests

In this experiment, we examined the degree to which four implicit tests and two explicit tests, all involving auditory presentation, were sensitive to the perceptual characteristics of the stimuli presented during study. Presenting stimuli visually decreased priming in all the implicit memory tests, relative to auditory presentation. However, changing voice between study and test decreased priming only in the implicit memory tests requiring identification of words degraded by noise or by low-pass filtering, but not in those tests requiring generation from word portions (stems and fragments). Modality effects without voice effects were observed in cued recall, but the opposite pattern of results (voice effects without modality effects) was obtained in recognition. The primary new finding is the demonstration that auditory memory tests, both explicit and implicit, differ in their sensitivity to the perceptual information encoded during study.     

Proving theorems of the second order Lambek calculus in polynomial time

In the Lambek calculus of order 2 we allow only sequents in which the depth of nesting of implications is limited to 2. We prove that the decision problem of provability in the calculus can be solved in time polynomial in the length of the sequent. A normal form for proofs of second order sequents is defined. It is shown that for every proof there is a normal form proof with the same axioms. With this normal form we can give an algorithm that decides provability of sequents in polynomial time.The author was sponsored by project NF 102/62–356 (Structural and Semantic Parallels in Natural Languages and Programming Languages), funded by the Netherlands Organization for the Advancement of Research (NWO).Presented byCecylia Rauszer     

Juvenile homicide: A growing national problem

Arrests for juvenile homicide more than doubled from 1984 to 1991. The present study examined offense characteristics for a national sample of 2,400 juvenile homicide offenders listed in the FBI Supplemental Homicide Reports for 1984 or 1991. Analyses indicate that the largest increases in juvenile homicide can be found among minority males using handguns to kill acquaintances. Juvenile homicides committed in the course of another crime (such as robbery or drug deal) have increased over 200%, while homicides precipitated by an interpersonal conflict with the victim have increased 83%. In comparison to adults, juvenile homicide offenders are much more likely to use a handgun and to act with an accomplice. These results highlight the association between handguns and juvenile homicide.     

Interactive effects of social context and sex role identity on female self-disclosure during the acquaintance process

Female subjects who differed in masculinity and in femininity self-disclosed to a same-sex confederate in contexts that made either social/expressive motives or instrumental motives particularly salient. The confederate spoke first on each of four disclosure topics, presenting either intimate or nonintimate information in her disclosures. The results were consistent with our primary assertion that measures of sex role identity would accurately forecast contextual variations in female self-disclosure. Specifically, femininity tended to promote self-disclosure in social/expressive contexts while clearly inhibiting such exchanges in the instrumental context. Supplementary data revealed that the tendency of highly feminine participants to close up in the instrumental context stemmed not from problems in their contemporaneous interpersonal relationships with their partners, but rather from a concern that disclosing too much might adversely affect their partners' evaluation of their competencies. Although masculinity did not exert direct effects of female self-disclosure within any particular context, it did have an influence, for subjects high in femininity were highly self-revealing across contexts if they were also high in masculinity (i.e., androgynous).This research was supported by National Institute of Mental health Grant MH 43726-01 to David R. Shaffer.     

"Although We are Catholic, We are Dutch"—The Transition of the Dutch Catholic Church from Sect to Church as an Explanation for its Growth and Decline

The Dutch Catholic Church has experienced an immense growth and an equal measure of decline in the last two centuries. This article explains this development by using the sect-to-church theory, as has been developed by the rational choice theory of religion. This theory explains the growth and decline of a church by the degree of tension it has with society. Historical evidence is used to test this theory with regard to the Dutch Catholic Church. As long as that church was in tension with society it kept growing, but as soon as the tension decreased, which was already taking place prior to 1960, it declined.