A COGNITIVE THEORY OF PSYCHOPHYSICS. I

The fundamental premise of this paper is that subjects deal with stimulus information when performing psychophysical judgments. The coding strategy employed to manipulate this information depends upon the particular experimental procedure, which leads to unique psychophysical functions. Different methods impose different memory constraints upon the subject, thus producing a variety of sensitivity measures for the same stimulus attribute.     

Relative frequencies of numerical responses in ratio estimation1

This study investigated the frequency of different numerical responses in ratio estimation as a function of the numerical categories actually used by Ss. Analyses were conducted for three series of experiments involving magnitude and free-ratio estimation for the attributes of stimulus length, area, and distance. It was found that Ss use certain numerical categories (e.g., multiples of 1, 10, and 100) much more frequently than others (e.g., 37.5) and that the choice of category depends upon the order of magnitude of the response. The statistical implications for ratio scaling are not dramatic, but are worthy of notice.     

The Effects of College Residence Groups On Students' Self-Concepts,Goals, and Achievements

This study compared the traits and achievements of students in various living groups. Students in fraternities and sororities were found to be more socially oriented, and students in off-campus rooms or at home were less socially oriented on a wide variety of measures. When students' pre-college scores were controlled, there were few differences among the groups on self-ratings or life goals. Fraternity and sorority students had more college social achievements but were not superior in other areas of non-academic achievement or in grades. These results were interpreted as showing that the effects of living groups are small.     

Stimulus sequence and the exponent of the power function for loudness

In two experiments, 15 and 13 subjects estimated the loudness of 12 sound-pressure levels (38-104 dB; 6-dB intervals) of a 1000-Hz tone by the method of magnitude estimation with a modulus assigned to the first stimulus presented. The tone duration was 1 sec. and the interstimulus interval was 6 sec. The presentation order was systematically ascending-descending in one experiment and balanced-irregular in the other. The results indicate that (1) loudness is a power function of sound pressure with an exponent of 0.60 for the systematic order and 0.29 for the irregular order. (2) For both the irregular and systematic orders, a large step-size (12 or 18 dB) between the stimulus on Trial n and on Trial n-1 (or n-3) results in a slight assimilation effect. This also occurs for the small step-size (6 dB) in the irregular order. (3) The size of momentary exponents (based on two points, Trials n and n-1 or n-3) depends on the sound pressures of successive stimuli, whether the steps are positive or negative, and whether the stimuli have been presented in systematic or irregular order. For positive steps, the momentary exponent is lower for a soft tone (Trial n) than for a loud tone, whereas for negative steps the momentary exponent is lower for a loud tone than for a soft tone. These effects ar more pronounced when these stimuli are presented in an irregular order. A relative judgment model is offered for magnitude estimation. It assumes that subjects judge the loudness of a stimulus in terms of three reference markers: the minimum and maximum sound pressures as well as the sound pressure of the previous stimulus.     

Transformation theory of size judgment.

Perception of size is assessed by having observers adjust a comparison target at a fixed distance to match the size of a standard located at different distances. Results depend on instructions, target orientation, and available stimulus cues. A mathematical theory assumes that the brain performs an inverse transformation on the proximal information impinging on the retina to recover the original distal size of the target. Results depend on the target visual angle, and the effective target distance and orientation applied in performing the inverse transformation. Effective values are linked to instructions, target location, and stimulus cues. Two models are developed and successfully fit to empirical data. One emphasizes the distance parameter; the second, the orientation parameter.     

Mexican-American adolescent sexuality and sexual knowledge: an exploratory study

This article reports the findings of a study designed to examine the sexual knowledge, attitudes, and practices of low-income Mexican- American adolescents. The participants in the study were all about to begin a sex education program in a community health organization in East Los Angeles. The study involved 84 adolescents aged 14-19, 97% of who identified themselves as Mexican-American (the remainder identified themselves as Latino). 51 of the subjects were female and 33 male. The participants completed a 43-item questionnaire concerning demographics, sexual experience and contraceptive use, knowledge of birth control methods, and attitudes towards sexuality and birth control. Only 18 (21%) of the subjects indicated ever having sex. But among this group, 83% reported not using contraception during their last intercourse, and 61% reported never using contraception. Only 22% reported using contraception regularly. Concerning the knowledge of different birth control methods,many of the participants were able to list several methods, but their responses indicated a lack of accurate and specific knowledge about contraceptive methods. In addition to the 43-item questionnaire, 27 of the subjects also completed a sexual and contraceptive knowledge questionnaire. The topics included contraceptive effectiveness, the menstrual cycle, and fertilization. The scores on the questionnaire were low, with an average score of 33% of correct answers. Finally, all 84 participants responded to a sexual attitude questionnaire, which revealed a generally traditional attitude toward the importance of have children, virginity, and the relationship between sex and love.     

The creative role of doubt in religion

This essay contains four arguments in defense of the creative role of doubt in religion. Within a specified framework or context it is argued that: 1) creative doubt is a means of constructively acknowledging human finitude, 2) creative doubt can play a role in keeping one's fundamental beliefs alive and vital, 3) creative doubt, by continually challenging the full adequacy of religious symbols, serves as a check against the idolatrous worship of one's own religious language, and 4) the avoidance of doubt may reflect a relinquishing of freedom and a dehumanizing quest for certainty.