Support for a two-factor model of impulsivity and hazardous substance use in British and Australian young adults

Multiple lines of evidence suggest impulsivity comprises two distinct components relevant to substance misuse. Reward drive reflects sensitivity to rewarding stimuli and subsequent approach motivation. Rash impulsiveness reflects the ability to inhibit such approach behavior in light of negative consequences. However, several studies suggest the latter trait to be a more robust predictor. This begs the question as to whether a less parsimonious two-factor model is necessary. This study employed structural equation modeling to compare the fit of one- and two-factor impulsivity models to alcohol and drug use data provided by British (n = 183) and Australian (n = 271) young adults. Results consistently supported the two-factor model and its cross-cultural consistency, with rash impulsiveness being the more robust predictor.     

The effect of a peripheral stimulus on accommodation

Accommodation was measured by the laser scintillation technique while the S viewed a stationary fixation spot through a series of apertures in a screen located at various distances. The magnitude of accommodation was a compromise between the distance of the fixation spot and the screen. Accommodation was affected significantly by the interaction of the distance of the screen with aperture sizes of 1 and 4 deg and distance of the screen with its order of movement from near to far or far to near. The data are interpreted as implying the importance of the peripheral visual field and/or perceptual factors when conflicting cues to distance coexist in the visual field.     

Further studies of the McCollough effect

Following prolonged viewing of black and white striped pattems in colored light, red and green aftereffects that lasted as long as 3 days were seen on the patterns, illuminated with white light. Altemate exposures of a vertical pattern of stripes in green light and a horizontal in white light (or a vertical in white light and a horizontal in red light) produced a red aftereffect on the vertical pattern and a green on the horizontal. The red and green aftereffects were also produced with a single vertical pattern. Adaptation colors that were at all greenish produced a red aftereffect on a vertical pattern and a green on a horizontal, whereas colors that were at all reddish produced a green aftereffect on a vertical pattern and a red on a horizontal. Colors near pure blue and pure yellow, which had little red or green content, produced weak aftereffects. The saturation of the aftereffects on the vertical grating varied in proportion to the red or green content of the adaptation color. Vivid red and green aftereffects were frequently obtained with the vertical and horizontal adaptation patterns paired with colors that closely bracketed pure yellow or pure blue. In all cases, the aftereffects gradually desaturated as the head was gradually tilted down to the side; the colors on each test pattern, vertical and horizontal, vanished at 45-deghead tilt and reversed beyond 45 deg.     

Two studies examining the negative effect of self-efficacy on performance

Although hundreds of studies have found a positive relationship between self-efficacy and performance, several studies have found a negative relationship when the analysis is done across time (repeated measures) rather than across individuals. W. T. Powers (1991) predicted this negative relationship based on perceptual control theory. Here, 2 studies are presented to (a) confirm the causal role of self-efficacy and (b) substantiate the explanation. In Study 1, self-efficacy was manipulated for 43 of 87 undergraduates on an analytic game. The manipulation was negatively related to performance on the next trial. In Study 2, 104 undergraduates played the analytic game and reported self-efficacy between each game and confidence in the degree to which they had assessed previous feedback. As expected, self-efficacy led to overconfidence and hence increased the likelihood of committing logic errors during the game.     

Body tilt effect on the reproduction of orientations: studies on the visual oblique effect and subjective orientations

Body tilt effects on the visual reproduction of orientations and the Class 2 oblique effect (E. A. Essock, 1980) were examined. Body tilts indicate whether the oblique effect (i.e., lower performance in oblique orientations than in vertical-horizontal orientations) is defined in an egocentric or a gravitational reference frame. Results showed that the oblique effect observed in upright posture disappeared in tilted conditions, mainly due to a decrease in the precision of the vertical and horizontal settings. In tilted conditions, the subjective visual vertical proved to be the orientation reproduced the most precisely. Thus, the oblique effect seemed to be not purely gravitationally or egocentrically defined but, rather, to depend on a subjective gravitational reference frame tilted in the same direction as body tilts.     

An exploratory field experiment of the effect of subconscious and conscious goals on employee performance

The effect of both a primed and a conscious goal on performance in the workplace was investigated. The primed goal was pilot tested. People on their way to work (n = 52) shown a photo of a woman winning a race performed better on a brainstorming task within a 2-min time period than people in the control group. A laboratory experiment (n = 71) revealed that this primed goal significantly increased the participants’ subconscious need for achievement, as measured by a projective test, relative to those in the control group. A 2 (primed goal vs. control group) × 2 (conscious goal vs. do best goal) factorial design involving call center employees (n = 81) revealed a main effect for this primed goal, as well as a main effect for a conscious goal for money solicited from donors.     

Confinement has no effect on visual space perception: The results of the Mars-500 experiment

People confined to a closed space live in a visual environment that differs from a natural open-space environment in several respects. The view is restricted to no more than a few meters, and nearby objects cannot be perceived relative to the position of a horizon. Thus, one might expect to find changes in visual space perception as a consequence of the prolonged experience of confinement. The subjects in our experimental study were participants of the Mars-500 project and spent nearly a year and a half isolated from the outside world during a simulated mission to Mars. The participants were presented with a battery of computer-based psychophysical tests examining their performance on various 3-D perception tasks, and we monitored changes in their perceptual performance throughout their confinement. Contrary to our expectations, no serious effect of the confinement on the crewmembers’ 3-D perception was observed in any experiment. Several interpretations of these findings are discussed, including the possibilities that (1) the crewmembers’ 3-D perception really did not change significantly, (2) changes in 3-D perception were manifested in the precision rather than the accuracy of perceptual judgments, and/or (3) the experimental conditions and the group sample were problematic.     

The effect of dextroamphetamine on habituation of peripheral vascular response in children

The blood volume pulse (BVP) measured by a photoplethysmograph was recorded in 43 children with behavior and learning problems before and after either stimulant drug treatment or placebo. A series of twenty-four 750-cps tones was presented at 10-sec. intervals, with one trial having a doubled interval and one with a halved interval. A 1,000-cps tone was introduced following the 24th trial. As predicted, the drug-treated subjects showed significantly more rapid habituation to the tones. They also showed more variability of BVP following the longer intertriai interval, but showed less variability following the introduction of the high tone. The results are interpreted as showing that the stimulant has the effect of raising autonomie arousal level with consequently more rapid habituation of the orienting response.An earlier version of this article was presented to The Society for Psychophysiological Research, Monterey, California, October 1969. This research was supported by Grant No. MH14432 from the Psychopharmacology Section (National Institute of Mental Health) and Research Scientist Development Award No. K2MH7839 (National Institute of Mental Health).     

Taboo words: The effect of emotion on memory for peripheral information

In three experiments, we examined memory for peripheral information that occurred in the same context as emotion-inducing information. In the first two experiments, participants studied either a sentence (Experiment 1) or a pair of words (Experiments 2A—2C) containing a neutral peripheral word, as well as a neutral, negative-valence, or taboo word, to induce an emotional response. At retrieval, the participants were asked to recall the neutral peripheral word from a sentence fragment or emotion-inducing word cue. In Experiment 3, we presented word pairs at encoding and tested memory with associative recognition. In all three experiments, memory for peripheral words was enhanced when it was encoded in the presence of emotionally arousing taboo words but not when it was encoded in the presence of words that were only negative in valence. These data are consistent with priority-binding theory (MacKay et al., 2004) and inconsistent with the attention-narrowing hypothesis (Easterbrook, 1959), as well as with object-based binding theory (Mather, 2007).     

The effect of type of behavior on behavior change caused by type of upcoming food substance

Previous research suggests that rats will decrease their consumption of a low-valued substance if a high-valued one will soon be available (anticipatory contrast), but will increase their rate of operant responding for a low-valued substance if a high-valued one will soon be available (positive induction). The present experiments tested whether rats would increase their operant rate of licking or lever pressing for 1% liquid-sucrose reinforcement when 32% sucrose reinforcement was upcoming in the same session. Results indicated that upcoming 32% sucrose increased rates of lever pressing for 1% sucrose, but did not produce similar increases in rates of licking. In fact, upcoming 32% sucrose significantly reduced lick rates in Experiment 2. The present results suggest that the different changes in behavior may be linked to the specific response that the subjects must engage in to obtain the reward (i.e., licking vs. lever pressing), and not to the function of the behavior (i.e., consummatory vs. operant) or to how frequently the substances are available (i.e., continuously vs. intermittently).     

The effect of varying alveolar carbon dioxide levels on free recall

A recent study suggested that students who have increased minute ventilation receive poorer grades. The present study was interested in determining the role alveolar carbon dioxide (CO2) levels play with cognitive abilities. A free recall task was used to examine list learning under two conditions of alveolar CO2 level: normal and decreased. The results suggested that decreased alveolar CO2 level affect the participant's ability to rehearse and recall information. It was concluded that conditions that reduce alveolar CO2 levels, such as hyperventilation resulting from stress, nervousness, or inappropriate breathing habits, can lead to poorer learning. If these conditions produce a habitual breathing pattern, the academic performance of the individual may suffer.     

A new approach to identifying the effect of diabetic peripheral neuropathy on the ability to drive safely

The purpose of this study was to estimate the potential for impaired driving performance in current drivers with diabetic peripheral neuropathy compared to healthy controls. We analysed, using a driving simulator, three important aspects of driving - use of the accelerator pedal, steering wheel and eye-steering coordination - to test for any differences, and then to integrate these findings to identify a unique pattern of changes in people driving with diabetic peripheral neuropathy. Patients with diabetic peripheral neuropathy displayed differences in use of the accelerator pedal compared to healthy control drivers (p < 0.05) which could be a direct consequence of their sensorimotor impairment due to diabetic peripheral neuropathy. Drivers with DPN used the more extreme high and low positions of the pedal to a greater extent than the Control group who exhibited a more graded use of the accelerator pedal over the mid-range. Eye-steering coordination was also different in drivers with diabetic peripheral neuropathy (p < 0.05) and, as it improved during the second drive, becoming closer to healthy drivers’ values, the occasional loss of control experienced during driving reduced. These insights demonstrate that diabetic peripheral neuropathy affects multiple aspects of driving performance suggesting the need for an integrated approach to evaluate the potential for driving safely in this population.