Similarities of low-dimensional chaotic auditory attractor sequences to quasirandom noise.

The production of sequences of sounds of various pitch levels from the algebra of chaotic attractors' trajectories is relatively straightforward. Meyer-Kress (cited in Kaneko, 1986) suggested that such sequences would be distinguishable from random independent identically distributed sequences. In psychophysical terms, this is a pattern-discrimination or pattern-similarity perception task, but these two tasks are not exactly the same thing. Nine attractors from the algebras of Henon, Zaslavskii (1978), Kaplan and Yorke (1979), Lorenz, and Gregson, and the logistic and Baker transformations, were paired with 10 realizations of a random series. The identification of the random member in each pair, the confidence of identification, and the perceived pairwise similarity were recorded by 65 subjects without initial feedback and by 76 subjects with initial feedback on five trials only, for each of 20 such pairs. The results indicate varying degrees of discriminability; they can be expressed in an analog of the receiver-operating characteristics of the attractors. There is no evidence of any homogeneous basis for the discrimination, and subjects who perform better are apparently not using the same bases as those who perform poorly. The fractal dimensionality of attractors may furnish a basis for their recognition, or the consequent autoregressive spectra induced in finite (short) samples, but recent work suggests the latter spectra can be insensitive to low-dimensional attractor dynamics.     

Similarities of low-dimensional chaotic auditory attractor sequences to quasirandom noise

The production of sequences of sounds of various pitch levels from the algebra of chaotic-attractors’ trajectories is relatively straightforward. Meyer-Kress (cited in Kaneko, 1986) suggested that such sequences would be distinguishable from random independent identically distributed sequences. In psychophysical terms, this is a pattern-discrimination or pattern-similarity perception task, but these two tasks are not exactlythe same thing. Nine attractors from the algebras of Henon, Zaslavskii (1978), Kaplan and Yorke (1979), Lorenz, and Gregson, and the logistic and Baker transformations, were paired with 10 realizations of a random series. The identification of the random member in each pair, the confidence of identification, and the perceived pairwise similarity were recorded by 65 subjects without initial feedback and by 76 subjects with initial feedback on five trials only, for each of 20 such pairs. The results indicate varying degress of discriminability; they can be expresssed in an analog of the receiver-operating characteristica-of the attractors. There is no evidence of any homogeneousbasis for the discrimination, and subjects who perform better are apparently not using the same bases as those who perform poorly. The fractal dimensionality of attractors may furnish a basis for their recognition, or the consequent autoregressive spectra induced in finite (short) samples, but recent work suggests the latter spectra can be insensitive to low-dimensional attractor dynamics.     

Perceived Contraceptive Attributes and Method Choice1

This research investigated the relationship of perceived contraceptive attributes to contraceptive choice. More specifically, the study a) examined what attributes women perceive as important in their choice of a contraceptive method; b) compared women who use the vaginal sponge with women who use oral contraceptives or the diaphragm on perceived importance of attributes; and c) compared sponge users with pill users and diaphragm users on perceived characteristics of three contraceptive methods. Data were collected in telephone interviews from a national sample of 330 current sponge users and 330 women who use other forms of female contraception. Those attributes that were rated highest concerned effectiveness and safety, whereas those that were rated lowest focused on convenience of use and interference with sexual activity. Women differed somewhat by user status on the attributes they believe are important in contraceptive choice, with each group emphasizing those attributes characterizing their own method. Moreover. each user group perceived their own method more favorably than did users of other methods. Perceptions of specific contraceptive methods. particularly the sponge. were more predictive of user status than were general importance ratings.     

Contrast thresholds for identification of numeric characters in direct and eccentric view

Aubert and Foerster (1857) are frequently cited for having shown that the lower visual acuity of peripheral vision can be compensated for by increasing stimulus size. This result is seemingly consistent with the concept of cortical magnification, and it has been confirmed by many subsequent authors. Yet it is rarely noted that Aubert and Foerster also observed a loss of the "quality of form." We have studied the recognition of numeric characters in foveal and eccentric vision by determining the contrast required for 67% correct identification. At each eccentricity, the lowest contrast threshold is achieved with a specific stimulus size. But the contrast thresholds for these optimal stimuli are not independent of retinal eccentricity as cortical magnification scaling would predict. With high-contrast targets, however, threshold target sizes were consistent with cortical magnification out to 6 degrees eccentricity. Beyond 6 degrees, threshold target sizes were larger than cortical magnification predicted. We also investigated recognition performance in the presence of neighboring characters (crowding phenomenon). Target character size, distance of flanking characters, and precision of focusing of attention all affect recognition. The influence of these parameters is different in the fovea and in the periphery. Our findings confirm Aubert and Foester's original observation of a qualitative difference between foveal and peripheral vision.     

Shape recognition contributions to figure-ground reversal: which route counts?

Observers viewed upright and inverted versions of figure-ground stimuli, in which Gestalt variables specified that the center was figure. In upright versions, the surround was high in denotivity, in that most viewers agreed it depicted the same shape; in inverted versions, the surround was low in denotivity. The surround was maintained as figure longer and was more likely to be obtained as figure when the stimuli were upright rather than inverted. In four experiments, these effects reflected inputs to figure-ground computations from orientation-specific shape representations only. To account for these findings, a nonratiomorphic mechanism is proposed that enables shape recognition processes before figure-ground relationships are determined.     

Children's and adults' sex-stereotyped perceptions of infants

Sex-stereotyped perceptions of infants were examined in children (aged 5, 9, and 15 years), college students, and the children's mothers. The children and college students as a group rated labeled female infants as littler and as more beautiful, nice, and soft than labeled male infants, with no age changes in sex-stereotyped perceptions. The mothers as a group were not influenced by the labeled sex manipulation. The 5-year-olds rated the infants the least favorably and the mothers rated the infants the most favorably. Girls rated the infants as more beautiful than the boys did. Finally, the mothers with higher masculinity scores and their sons showed less sex-stereotyped perceptions of the infants than mothers with lower masculinity scores and their sons.     

Effects of background symmetry onsame-different pattern matching: A compromise-criteria account

Two experiments are reported, which were designed to test predictions of an account ofsame-different matching that assumes that bilaterally symmetric backgrounds provide extraneous evidence towardsame, whereas asymmetric backgrounds provide evidence towarddifferent. When all backgrounds within a block of trials are of the same type, appropriate adjustments of response criteria can be made to accommodate the irrelevant evidence and thus maintain acceptable levels of accuracy. However, when backgrounds of different types are mixed randomly, compromise criteria are adopted. This compromise-criteria account predicts distinctive interaction patterns for reaction times when blocked versus mixed presentations of various background types are compared. The predicted interactions were obtained for asymmetric- and no-noise backgrounds in Experiment 1 and forsymmetric-, asymmetric-, and no-noise backgrounds in Experiment 2. The findings support the general view that extraneous display attributes are weighted into the evidence for same anddifferent, with criteria settings used that minimize errors under the noisiest conditions.     

Towards an empirical definition of courage

Receiving attribution of courage or bravery is important to most of us. Three possible modes of attribution are outlined, two of which are taken to be naive (i.e., attributing bravery if one is afraid oneself or identifying bravery with fearlessness), only one is taken as sophisticated i.e., bravery as a result of approach by a fearful person. Inferences about the use of these modes are made on the basis of correlational patterns in the data of adolescent subjects who watched snake-handling by a filmed actor/actress. Subjects rated themselves for hypothetical fear (if they had had to handle the snake): in addition they rated the handler on fear or bravery. Results suggested an increasing use of the sophisticated mode of attribution with increasing age. Clear use of the sophisticated mode however was not demonstrated in the case of attributing to female actresses. Possible interpretations of this sex of attributee effect are taken up in the Discussion.     

Separation-individuation conflicts in children of Holocaust Survivors

This article examines the developmental conflicts of children of Holocaust Survivors with specific emphasis on psychic trauma and second-generation Survivor effects. Issues related to depression, guilt, and aggression are discussed in relation to Mahler's separation-individuation process. Developmental failures at early phases may predispose these children toward low self-esteem, narcissistic vulnerability, identity problems, and impairments in interpersonal relations. The need for further research and clinical investigation is emphasized to help develop preventive measures and attenuate the effects of the Holocaust on future generations.