Effects of Crowding in a Student Environment1

Responses to crowding were examined in two student dormitories (Dorm A and Dorm B). Dorm B had more rooms per floor, smaller sized rooms, and a general layout which seemed conducive to a higher level of social stimulation. Students living in Dorm B reported being less involved with their roommates, being in a worse mmod, and experiencing more crowding. The role of crowding in mediating the relationship between type of dormitory as an independent variable and mood and interpersonal relationship as dependent variables was discussed.     

The effect of spatial order on piecemeal shape recognition: A developmental study

Stationary shapes were displayed piecemeal by moving an aperture from one place to another around their contours. Shape recognition was poorer with an unpredictable order of display. This result is more consistent with hypothesis-testing than with either eye-movement or visual information models of shape recognition. Shape recognition was poorer for 9- and 11-year-old children than for adults.     

Understanding supervisor-targeted aggression: a within-person, between-jobs design

The authors investigated predictors of supervisor-targeted workplace aggression among 105 "moonlighters" (employed adults who work 2 jobs, each with a different supervisor), as a way of examining the relative role played by within-subject situational differences and between-subjects individual differences. Individual difference variables (self-esteem, history of aggression) explained a similar level of variance in aggression across both jobs, whereas situational factors (interactional injustice, abusive supervision) were job specific and explained proportionally more variance than did individual differences.     

Effects of reinforcement schedule on facilitation of operant extinction by chlordiazepoxide

Learning and memory are central topics in behavioral neuroscience, and inbred mice strains are widely investigated. However, operant conditioning techniques are not as extensively used in this field as they should be, given the effectiveness of the methodology of the experimental analysis of behavior. In the present study, male C57B1/6 mice, widely used as background for transgenic studies, were trained to lever press on discrete-trial fixed-ratio 5 or fixed-interval (11 s or 31 s) schedules of food reinforcement and then exposed to 15 extinction sessions following vehicle or chlordiazepoxide injections (15 mg/kg i.p., administered either prior to all extinction sessions, or prior to the final 10 extinction sessions). Extinction of operant behavior was facilitated by drug administration following training on either schedule, but this facilitation only occurred once a number of extinction sessions had taken place. The extinction process proceeded more rapidly following fixed-interval training. Resistance to extinction was equally high following training with either schedule type, and was reduced by drug administration in both cases. These phenomena were evident in individual cumulative records and in analyses of group data. Results are interpreted in terms of phenomena of operant extinction identified in Skinner's (1938) Behavior of Organisms, and by behavioral momentum theory. These procedures could be used to extend the contribution of operant conditioning to contemporary behavioral neuroscience.     

Involuntary attentional shifts due to orientation differences

We tested the ability of orientation differences to cause involuntary shifts of visual attention and found that these attentional shifts can occur in response to an orientation “pop-out” display. Texturelike cue stimuli consisting of discrete oriented bars, with either uniform orientation or containing a noninformative orthogonally oriented bar, were presented for a variable duration. Subsequent to or partially coincident with the cue stimulus was the target display of a localization or two-interval forced-choice task, followed by a mask display. Naive subjects consistently showed greater accuracy in trials with the target at the location of the orthogonal orientation compared with trials with uniformly oriented bars, with only 100 msec between the cue and mask onsets. Discriminating these orientations required a stimulus onset asynchrony (SOA) of 50–70 msec. The attentional facilitation is transient, in most cases absent, with a cue-mask SOA of 250 msec. These results suggest that the preattentive character of some texture discrimination tasks with SOAs of only 100 msec is vitiated by the involuntary attentional shifts that are caused by orientation differences.