Difference measurement spaces

An absolute-difference measurement space is a pair (X, e) where the real-valued function e on X² satisfies conditions which are shown in the paper to be necessary and sufficient for its representability by the absolute distance on the real line. A positive-difference measurement space is a pair (X, l), where the real-valued function l on X² satisfies conditions necessary and sufficient for its representability by positive distances on the real line. The conditions imposed on e and l make these functions extensive measurements of proximity and dominance, the two basic predicates of social enquiry. Another way of treating these conditions is to translate them to the formal language of multivalued logic. The translation is easy and the sentences obtained have plausible intuitive meanings such as reflexivity, symmetry, and transitivity. The two sets of conditions thus become formal theories of proximity and dominance. Our difference measurement spaces are relational structures for the multi-valued logic and models of the two formal theories. Thus proximity and dominance are considered dichotomous in principle and the multiple truth-values represent degrees of error. We suggest adopting multivalued logic as a framework within which the problem of measurement error can be treated together with the formal axiomatization of social and phychological theories.     

The eccentricity effect: Target eccentricity affects performance on conjunction searches

The serial pattern found for conjunction visual-search tasks has been attributed to covert attentional shifts, even though the possible contributions of target location have not been considered. To investigate the effect of target location on orientation × color conjunction searches, the target’s duration and its position in the display were manipulated. The display was present either until observers responded (Experiment 1), for 104 msec (Experiment 2), or for 62 msec (Experiment 3). Target eccentricity critically affected performance: A pronounced eccentricity effect was very similar for all three experiments; as eccentricity increased, reaction times and errors increased gradually. Furthermore, the set-size effect became more pronounced as target eccentricity increased, and the extent of the eccentricity effect increased for larger set sizes. In addition, according to stepwise regressions, target eccentricity as well as its interaction with set size were good predictors of performance. We suggest that these findings could be explained by spatial-resolution and lateral-inhibition factors. The serial self-terminating hypothesis for orientation × color conjunction searches was evaluated and rejected. We compared the eccentricity effect as well as the extent of the orientation asymmetry in these three conjunction experiments with those found in feature experiments (Carrasco & Katz, 1992). The roles of eye movements, spatial resolution, and covert attention in the eccentricity effect, as well as their implications, are discussed.     

Posture and Prediction on the Attitudes Toward Women Scale

A study was performed investigating the relationship between stated attitudes toward the feminist movement and willingness to help that movement. Results suggested that Attitudes Toward Women Scale (AWS) measures of feminist commitment may be limited by a social desirability variable and that high scores on the AWS do not correlate with a behavioral measure of commitment.     

Cocaine and food as reinforcers: effects of reinforcer magnitude and response requirement under second-order fixed-ratio and progressive-ratio schedules.

Reinforcer magnitude and fixed-ratio requirement were varied under two second-order schedules. Under one, the first sequence of a fixed number of responses completed after the lapse of a 10-min fixed interval produced reinforcement. Under the second, a second-order progressive-ratio schedule, the fixed number of responses increased after each reinforcement. Either cocaine (0 to 300 micrograms/kg/inj) or food (0 to 5,700 mg/delivery) reinforcers were delivered. Under some conditions, a 2-s illumination of stimulus lights occurred on completion of each ratio sequence. Under the second-order schedule, as cocaine dose or amount of food increased, rates of responding increased; at the highest values, rates of responding decreased. Increases in the ratio requirement from 10 to 170 responses minimally decreased overall response rates. Under the second-order progressive-ratio schedule, increases in dose of cocaine or amount of food increased rates of responding; at the highest amounts of food, rates of responding decreased but response rates at the highest dose of cocaine remained relatively high. The highest ratio requirement that was completed (breaking point) depended on the dose of cocaine but was less dependent on the amount of food. Removing brief-stimulus presentations had a greater effect on completion of ratio requirements with cocaine compared to food.     

Biases in Visual Attention in Depressed and Nondepressed Individuals

Abstract

The present study utilised a cognitive paradigm to examine attentional biases in mildly depressed persons. Twelve depressed and 12 nondepressed subjects completed an attentional task similar to that employed by MacLeod, Mathews, and Tata (1986). A tachistiscope was used to present subjects with a series of word pairs, each with one word printed above the other. Three types of word pairs were presented: manic-neutral, depressed-neutral, and manic-depressed. Selective attention to one member of a word pair was assessed using ac perception task. Based on cognitive models of depression, it was hypothesised that the depressed subjects would attend more to depressed-content words than to manic- or neutral-content words, whereas the nondepressed subjects would not exhibit any attentional biases. In contrast to these predictions, analyses indicated that whereas the depressed subjects attended equally to depressed-, manic-, and neutral-content words, the nondepressed subjects attended more to manic-content than they did to neutral- or depressed-content words. These results add support to the documentation of evenhandedness in the cognitive functioning of depressed subjects, and of self-sewing biases in nondepressed subjects. The present findings are discussed in terms of a zoom lens model of attention, in which depressed persons attempt to exhaustively process their sensory world, but with a loss of attentional resolution. In contrast, nondepressed individuals attempt to process a more limited portion of their sensory world, but with an increase in attentional power. Finally, directions for future research in this area are offered.