Two-stage model of visual backward masking: Sensory transmission and accrual of effective information as a function of target intensity and similarity

A functional model is used to describe the effect of target intensity and target-set similarity on backward visual masking. The model consists of two distinct stages of visual information processing. The first stage is related to sensory transduction and transmission and is assumed to require a finite and measurable amount of time during which performance-remains at chance. The second stage, associated with central processing, is characterized by a negatively accelerated growth function reflecting the accrual of effective information. Results show that the duration of the transmission stage is inversely related to target intensity. Surprisingly, the rate of information accrual is an interactive function of both target intensity and target-set similarity. The pattern of results is consistent with the interpretation that both intensity and similarity mediate their effect through a common mechanism—the accrual of effective information.     

Programming in natural language: A descriptive analysis

This study investigated the utility of natural language in specifying procedures. Performance of programmers was compared with that of nonprogrammers on two types of problems: a “real-world” ordering task and a computer like database search task. Programmers performed better than nonprogrammers in general, although overall differences between the groups were greater for the real-world problem domain. Analyses of protocols suggest that an unconstrained natural language programming environment is presently infeasible. Although constraints imposed in the problem specification do appear to improve performance, they alone are not sufficient to produce efficient natural language programming. It is argued that programming requires general problem solving strategies and that at least some aspects of such strategies may be dependent upon the specific language in which they are implemented.     

Chromatic information processing: Rate depends on stimulus location in the category and psychological complexity

Summary Colors are typically categorized, and color sensations can be conceived to lie on a continuum of psychological complexity from simple, sensations provoked by colors that fall near the centers of color categories and that convey predominately a single percept (like blue), to complex, sensations provoked by colors that fall near boundaries between color categories and that convey two percepts (like blue-green). In three experiments we assessed the effect of the location of colors in a category (their psychological complexity) on the rate at which observers identified and classified them. In Experiment 1, observers named category center colors faster than boundary colors. A subsidiary experiment with range-shifted stimuli showed that observers were not merely bisecting a stimulus continuum. In Experiment 2, observers classified a variety of category centers more rapidly than a variety of boundaries. In Experiment 3, observers who first practiced classifying color centers or boundaries as such later classified category centers faster than boundaries. A subsidiary experiment showed that this differential was not selective to particular response category labels. Neither Experiment 2 nor Experiment 3 showed any differential effect of visual field of presentation. The advantage of category center or simple over boundary or complex sensations in chromatic information processing is discussed in terms of the physiological sensitivity of the visual system to color.     

Police Perceptions of Alcohol Intoxication

The accuracy of police perceptions of alcohol intoxication was assessed by comparing officers' impressions of intoxication with quantitative Breathalyzer measurements of blood alcohol concentration (BAC). Eighteen police officers predicted the BACs of 36 students who had consumed either a high or low dosage of alcohol. Results indicated that the officers could not discriminate between students who had consumed either the high or low alcohol dosage. More specifically, the officers were reasonably accurate in their predictions of students in the low alcohol condition, but they strongly underestimated the degree of intoxication of students in the high dose condition.     

Comparative judgments of animal intelligence and pleasantness

Symbolic comparisons of animal intelligence and pleasantness were investigated in five experiments using words and pictures as stimuli. Symbolic distance effects occurred in all experiments. Picture-word effects depended on the experimental design. Mean intelligence comparison reaction time (RT) did not differ for pictures and words when the pairs were presented to independent groups. With repeated measures, mean RT was faster for pictures than for words, but only on the second block of trials. This involved an asymmetrical transfer effect, so that word comparisons on the first trial block greatly facilitated picture comparisons on the second block, whereas picture comparisons did not facilitate subsequent word comparisons. Pleasantness comparisons showed a similar asymmetrical transfer pattern but differed from intelligence comparisons in that the mean RTs were faster with pictures than with words, even with an infinite item set and without prior exposure to the other class of material. The results are discussed in terms of dual coding and other models of symbolic comparisons.     

Discriminability of brightness change for infants

Four-month-old human infants who were habituated to a 490-nm stimulus of 3.5 cd · m^?2 luminance did not show recovery when the stimulus was increased or decreased in luminance by a factor of 2 but not changed in hue. A fourfold luminance increase produced a recovery in looking time. When compared with earlier results on simultaneous discrimination of brightness change, the results imply that infants differ from adults more in ability to code or retrieve than in ability to detect intensive differences. The implication is further supported by the differentiating response of infants to changes in hue.     

Focus of Attention and Employee Reactions to Job Change1

Two hundred and five telecommunications field-service technicians underwent a job change and responded to our questionnaire. The amount of time since experiencing the job change was measured for each technician. We found support for the hypothesis that the more an employee focuses on his or her job, the stronger that employee will react to a job change. Technicians who focused highly on their jobs reported fewer excused absences and were more job involved as time passed after the change, compared to technicians who focused little on their jobs. Moreover, high off-job focused technicians became less committed, less job involved, less satisfied, and more likely to leave over time. Focus also was related to perceptions of job complexity, and moderated the relationship between complexity and employee responses. These findings provide further support for hypotheses posited by Gardner, Dunham, Cummings, and Pierce (1987a, 1989) regarding employee focus of attention.     

A nonhuman primate's expectations about object motion and destination: The importance of self-propelled movement and animacy

Human infants have considerable understanding of why objects move and what causes them to take one trajectory over another. Here, we explore the possibility that this capacity is shared with other nonhumans and present results from preferential looking time tests with a New World monkey, the cotton-top tamarin. Experiments examined whether individuals form different expectations about an object's potential capacity to change locations. Test objects were: 1) self-propelled, moving, animate; 2) self-propelled, moving, inanimate; 3) non-self-propelled, moving due to an external agent, inanimate; 4) non-self-propelled, motionless, inanimate. When category 1 objects, either a live mouse or frog, emerged from behind an occluder in a novel location, this did not affect looking time; subjects appeared to expect such changes. In contrast, when the other objects emerged in a novel location following occlusion from view, subjects looked longer than when the object emerged in the location seen prior to occlusion; such locational changes were apparently not expected. Some feature other than self-propelled motion accounts for the tamarins’ looking time responses and at least one candidate feature is whether the object is animate or inanimate.