Drug testing,drug treatment,and marijuana use: a fairness perspective

The authors conducted a random statewide telephone survey of 1,484 individuals to study the relationship between marijuana use (in terms of participants' history of marijuana use) and reactions to drug testing and to study 2 hypothetical drug-treatment policies. Job safety sensitivity was related to perceived fairness of drug testing for the participant's job, and more recent marijuana use was associated with more negative reactions. Safety sensitivity was related to perceived fairness of drug treatment. Organizations with voluntary treatment were more attractive than ones with monitored treatment. Marijuana use interacted with drug treatment policy type in predicting reactions to drug treatment. Results suggest that organizations should consider job and employee characteristics when developing a drug treatment policy.     

Seeing stereoscopic depth from disparity between kinetic edges

Traditionally, it is assumed that stereovision operates only on the positional difference (disparity) between luminance-defined features in the images in the left and the right eye. Here, I show that stereoscopic depth can be seen from disparity between edges created by relative motion of texture elements, and between edges created by correlated flicker of stationary texture elements. Luminance-based stereopsis was impossible since the texture was binocularly uncorrelated. Positional disparity of the centre of revolving patterns was not an efficient depth cue. Stereopsis from the stimuli presented here was possible even without binocular overlap of textured areas. The results provide evidence that positional disparity of kinetic edges, defined by correlated flicker or motion contrast alone, can be used as matching features to recover stereoscopic depth.     

Hyperthermia impairs retrieval of an overtrained spatial task in the Morris water maze

Fifteen rats were trained to learn the location of a spatially fixed platform hidden in a Morris water maze (40 +/- 2 degrees C). Then retention of the spatial task was assessed immediately after raising core body temperature (Tc) to 42 or 40 degrees C or stabilizing at 37 degrees C (the normothermic control). The hyperthermic treatment order was counterbalanced according to a Latin-square design. Hyperthermia at 42 degrees C Tc significantly impaired spatial performance. Hyperthermic animals were cooled to normothermia (Tc = 37 degrees C) and spatial performance was tested again approximately 30 min later. Cooling resulted in a complete recovery of spatial performance. These results demonstrate that hyperthermia-induced amnesia can be obtained on an overtrained spatial-mapping strategy and cooling to normothermia initiates recovery of spatial performance.     

Visual associations cued recall A Paradigm for Measuring Episodic Memory Decline in Alzheimer’s Disease

Repeated measurements of episodic memory are needed for monitoring amnestic mild cognitive impairment (aMCI) and mild Alzheimer’s disease (AD). Most episodic memory tests may pose a challenge to patients, even when they are in the milder stages of the disease. This cross-sectional study compared floor effects of the Visual Association Test (VAT) and the Rey Auditory Verbal Learning Test (RAVLT) in healthy elderly controls and in patients with aMCI or AD (N = 125). A hierarchical multiple regression analysis was used to examine whether linear or quadratic trends best fitted the data of cognitive test performance across global cognitive impairment. Results showed that VAT total scores decreased linearly across the range of global cognitive impairment, whereas RAVLT total scores showed a quadratic trend, with total scores levelling off for 90% of aMCI patients and 94% of AD patients. We conclude that the VAT shows few if any floor effects in patients with aMCI and mild AD and is therefore a potentially promising cognitive test for monitoring episodic memory impairment.     

Localization of Syntactic Comprehension by Positron Emission Tomography

Positron Emission Tomography (PET) was used to determine regional cerebral blood flow (rCBF) when eight normal right-handed males read and made acceptability judgments about sentences. rCBF was greater in Broca's area (particularly in the pars opercularis) when subjects judged the semantic plausibility of syntactically more complex sentences as compared to syntactically less complex sentences. rCBF was greater in left perisylvian language areas when subjects had to decide whether sentences were semantically plausible than when subjects had to decide whether syntactically identical sentences contained a nonsense word. The results of this experiment suggest that overall sentence processing occurs in regions of the left perisylvian association cortex. The results also provide evidence that one particular aspect of sentence processing (the process that corresponds to the greater difficulty of comprehending center-embedded than right-branching relative clause sentences) is centered in the pars opercularis of Broca's area. This process is likely to be related to the greater memory load associated with processing center-embedded sentences.     

An attentional mechanism in the analysis of spatial frequency

Sinusoidal gratings of various spatial frequencies were used as masking stimuli in a detection task and a vernier acuity task. The test stimuli were 1 cycle/deg square-wave gratings. The spatial frequency of the most effective mask was 1 cycle/deg for the detection task but 3 cycles/deg for the vernier acuity task. The different masking functions for the two tasks show that the visual system analyzes the square-wave stimulus into its various spatial-frequency components. Since the test stimulus was the same for both tasks, the different masking functions may be the result of an attentional mechanism that weighs the importance of the output from various spatial-frequency analyzers. Whether the information from a particular spatial-frequency analyzer is attended or not depends upon the task the visual system must perform.     

Analysis of arterial blood gases in the curarized,artificially respira ted rat

The present paper describes a simple and accurate technique for the artificial respiration of curarized rats that avoids the trauma involved in a tracheotomy. Success of the technique depends on the proper positioning of a special face mask on the rat. The results of an experiment on arterial blood gases in 48 curarized rats are presented to illustrate the accuracy and effectiveness of the techniques described.     

Improvable,yes; insoluble,no: A reply to Flock

The relationship between apparent size and apparent depth in certain forms of the Müller-Lyer illusion is explored both Experimentally and theoretically. The Experimental results show that the apparent Sizes and apparent distances of the Müller-Lyer shafts in the normal and in the “reverse” illusions are related to each other. They also contradict specific predictions About the apparent depth location of Müller-Lyer shafts derived from the Misapplied size-constancy theory and Emmert’s Law. These results are interpreted In terms of the operation of the size-distance Principle, and this interpretation is supported by observations of other illusions.     

Human-computer interaction: A preliminary social psychological analysis

Considering an interactive computer as a social stimulus suggests that contemporary social psychological theories can contribute to the prediction of user attitude and performance. In order to assist in the systematic exploration of this possibility, we developed DIALOGUE, an on-line system to investigate the effects of varying the computer’s responses to the user. This system involves a presentation program that displays the computer’s responses, performs the pacing of video information, and collects a variety of measurements, including the user’s response time and the number of correct/incorrect user responses. DIALOGUE also includes a data manager that allows the experimenter to examine or modify the information collected by the presentation program. Utilizing DIALOGUE, we conducted a preliminary investigation of one aspect of human-computer interaction, the effects of varying the degree of human-like responses exhibited by the computer. Results suggest that (1) there are underlying dimensions of judgment involving perception of interactive computers, (2) a manipulation of human-like computer responses is reflected primarily in certain of these dimensions, and (3) such a manipulation influences user performance and feelings of responsibility. Factors related to the implementation of DIALOGUE are considered, and its potential for investigations of a variety of human-computer interactions is discussed.