On the nature of perceptual limits in vision

Summary Studies of attention have generally assumed that the principal limit to visual perception involves the capacity to identify a stimulus. Analyses of responses in visual tasks, however, suggest that errors can arise from a loss of position information, as well as a loss of identity information, and that these two types of errors may be affected by different variables. Based on this, we have proposed that the difficult aspect of perception is not that of recognizing the form of the stimulus but rather determining its position relative to other items in the field. To demonstrate this, we conducted a series of experiments on lateral masking that showed that the failure to perceive a parafoveal stimulus surrounded by other items is due to two quite separate components: a loss of identity information induced by the immediately adjacent items and a loss of position information induced by both adjacent and non-adjacent items.This research was supported by grant A-9581 from the Natural Sciences and Engineering Research Council of Canada to the senior author. The first two experiments were reported in a paper to the annual meeting of the Psychonomics Society, San Antonio, 1984     

Frog skin,time series,and other kinds of data: Nonisomorphic representation and analysis

Representational art is spatially congruent, or isomorphic, with objects in the world. In other words, they are the same in some important way. But not all representation is isomorphic. Data graphs are a type of nonisomorphic representation. A major goal of data graphs is to facilitate the rapid comprehension of differences or relations. This is done by providing a kind of analogy between something that can be “seen” (the relative heights of points) and some relevant information. This article discusses some rules about data graphing, then some new visualization tools are briefly critiqued.     

Subject-pool record keeping: A database application

This paper describes a record-keeping system we developed for our subject pool, utilizing ORACLE database software on a VAX computer. This system consists of three data tables and four processes: set up, updating, report generation, and editing. This article describes the rationale and function of each of these four processes in detail. All input and output is in ASCII format. The combination of ASCII files and the ORACLE database system produces a subject-pool recordkeeping system that is adaptable, expandable, and exportable.     

Dating Violence Prevention: A Didactic Support Group for Young Women

The authors discuss the social problem of dating violence and present a didactic support group model designed to empower young women to see themselves as “choice makers” with the ability to make informed decisions in their own best interest. They also present research findings that support the content of the group model and articulate some of their experiences in conducting this group in both high school and college settings. Finally, they discuss the potential impact of the group according to feedback from participants.     

Reading skill and the use of orthographic knowledge by Mature Readers

Summary Butler and Hains (1979) found individual differences in the effect of word length on RT in word naming and lexical-decision tasks; subjects scoring high on a vocabulary test were much less affected by word length than subjects with low scores. The present study attempted to determine whether such differences could be due to differences in the use of intraword structure, since word recognition has been linked, both empirically (Mason, 1978; Scheerer-Neumann, 1981) and theoretically (Mewhort & Campbell, 1981) to the use of orthographic redundancy. In Experiment 1, subjects were shown tachistoscopically presented letter strings varying in approximation to English. High vocabulary subjects were more capable of capitalizing on the redundancy with the higher-order approximations. Experiment 2 then established that performance on the vocabulary test was correlated with reading skill, measured by the Nelson-Denny Reading Test, and that skilled readers were more sensitive to the syllable structure in words. In the experiment, subjects were shown eight-letter words presented as three separate word units which either matched or violated syllable boundaries in the word. Skilled readers were more sensitive to the difference between syllable and nonsyllable units than were less skilled readers. The results obtained by Butler and Hains appear to reflect differences in reading skill and the efficiency of letter sequence parsing prior to word recognition.     

Perceived punishment and reward values of supervisor actions

The study investigated employee perceptions about the reward or punishment values inherent in a variety of supervisor actions. Actions viewed as most rewarding were generally actions that possessed (a) public visibility, (b) tangibility, (c) implied esteem, and (d) long-term implications. Actions viewed as punishing or aversive involved similar characteristics. Visibility appeared to be most strongly related to perceived severity. In contrast with suggestions in the literature (cf. León, 1981), substantial levels of agreement among raters were found for aversive as well as rewarding actions. Also reviewed are characteristics of leader actions that received mixed ratings from respondents.     

Analog SKED

Analog data can now be handled by SKED. Through the use of F3s, input, output, decisions, and analyses can be performed on analog data. A new command has been added to SKED. The trade off between number of boxes and resolution is discussed.