Discrimination of geometric angles by adult humans

Men and women learned to discriminate between two different size angles presented to them as objects within a real-world task. During Experiment 1, participants in group 50 were trained to choose a 50° angle and participants in group 75 were trained to choose a 75° angle. During testing, both groups were provided with a choice between their training angle and one of a set of test angles that was either smaller or larger than the training angle. Results showed a generalized pattern of responding, with group 50 showing increased responding to test angles smaller than 50° and group 75 showing increased responding to test angles larger than 75°. Further analysis of the response patterns revealed that participants in group 50 showed evidence of absolute learning, whereas participants in group 75 showed evidence of relational learning. During Experiment 2, a third group of participants (group 25) trained to choose a smaller angle (25°) was included in addition to group 50 and group 75. Participants were trained with three angles present and tested with just two, one being their training angle and the other being one of a set of novel test angles. Similar to the participants from Experiment 1, group 75 showed evidence of relational learning. Group 50, for which no relational rule could be applied during training, showed an absolute learning pattern with no response shift to test angles smaller or larger than their training angle. Group 25 showed evidence of absolute responding that was more pronounced than that found for the smallest training angle during Experiment 1. These findings suggest differential learning of geometric angles based on amplitude with smaller angles perceived as more distinct and thus more resistant to broader generalization than larger angles. Implications of these results are that certain geometric properties may be subject to different learning processes based on the specific magnitude of that property.     

Let the pigeon drive the bus: pigeons can plan future routes in a room

The task of determining an optimal route to several locations is called the traveling salesperson problem (TSP). The TSP has been used recently to examine spatial cognition in humans and non-human animals. It remains unclear whether or not the decision process of animals other than non-human primates utilizes rigid rule-based heuristics, or whether non-human animals are able to flexibly ‘plan’ future routes/behavior based on their knowledge of multiple locations. We presented pigeons in a One-way and Round-Trip group with TSPs that included two or three destinations (feeders) in a laboratory environment. The pigeons departed a start location, traveled to each feeder once before returning to a final destination. Pigeons weighed the proximity of the next location heavily, but appeared to plan ahead multiple steps when the travel costs for inefficient behavior appeared to increase. The results provide clear and strong evidence that animals other than primates are capable of planning sophisticated travel routes.     

The false consensus effect: A meta-analysis of 115 hypothesis tests

False consensus refers to an egocentric bias that occurs when people estimate consensus for their own behaviors. Specifically, the false consensus hypothesis holds that people who engage in a given behavior will estimate that behavior to be more common than it is estimated to be by people who engage in alternative behaviors. A meta-analysis was conducted upon 115 tests of this hypothesis. The combined effects of the tests of the false consensus hypothesis were highly statistically significant and of moderate magnitude. Further, the 115 tests of false consensus appear to be relatively heterogeneous in terms of significance levels and effect sizes. Correlational analyses and focused comparisons indicate that the false consensus effect does not appear to be influenced by the generality of the reference population, nor by the difference between alternative choices in actual consensus. However, the significance and magnitude of the false consensus effect was significantly predicted by the number of behavioral choices/estimates subjects had to make, and the sequence of measurement of choices and estimates. These patterns of results are interpreted as being inconsistent with the self-presentational, motivational explanation for the false consensus effect.     

Prejudice against women: A new perspective

Studies 1 and 2 of this paper were designed to reexamine the assumption that women and men are prejudiced against women. Subjects were 50 college women, 40 college men, 40 high-school women and 40 high-school men who were presented with four employment applications for evaluation. The names referring to the gender of the applicants were manipulated so that half of the subjects were shown the two most qualified applicants as female and the two least qualified as male. The other half of the subjects were shown the reverse of this. The results for this factor, with women subjects, revealed that the sex of the applicants did not interfere with or distort the subject's judgments (p>.25). The men subjects did not show a preference for or a prejudice against applicants of either sex (p>.05). The qualifications of the applicants were selected according to each subject's previous ranking of 10 job-related characteristics. The results for this factor, with women subjects, indicated a significant difference between the subjects' ranking of the characteristics and their final selection of the applicants (p<.05). The men subjects showed no significant difference between the subjects' rankings of the job-related characteristics and their rating of the applicants (p>.05). No significant interaction between factors was found for either population of subjects (p>.05). This research reflects changing attitudes of women towards women and provides new insights regarding men's attitudes toward their own sex.The authors of this paper would like to extend our sincere gratitude to Dr. John Schaeuble for his continuous support of this research endeavor.     

A versatile low-cost interface module that features optical isolation

The complete design and construction of a versatile low-cost interface module are presented. This module functions as a combination pulse lengthener-stretcher with an added feature of optical isolation between the input and output circuits. It is useful in interfacing many behavioral and physiological instruments that utilize different voltage levels and polarities in their respective logic systems. The cost of the components needed for module construction (without power supply) is approximately $15.     

Student mental health: how can psychiatrists better support the work of university medical centres and university counselling services?

Student psychiatric morbidity is rising. Whilst the influence of university counselling services is widely reported, NHS involvement by psychiatrists and general practitioners is not so well described. Counselling and mental health service providers for students at the University of Leeds were approached for numerical data and a university Group on Student Mental Health discussed the findings. The Student Counselling Centre, the University Medical Practice and a dedicated student psychiatric clinic have all seen a rise in referral rates. The University Medical Practice has also seen a rise in the prescribing of psychoactive medication. Collaborative links at the University of Leeds are explored and options for the future discussed. These include self-help over the internet, a research project to assess student mental health needs and the provision of a dedicated NHS psychiatric team for the university.     

Orienting in virtual environments: How are surface features and environmental geometry weighted in an orientation task?

We investigated how human adults orient in enclosed virtual environments, when discrete landmark information is not available and participants have to rely on geometric and featural information on the environmental surfaces. In contrast to earlier studies, where, for women, the featural information from discrete landmarks overshadowed the encoding of the geometric information, Experiment 1 showed that when featural information is conjoined with the environmental surfaces, men and women encoded both types of information. Experiment 2 showed that, although both types of information are encoded, performance in locating a goal position is better if it is close to a geometrically or featurally distinct location. Furthermore, although features are relied upon more strongly than geometry, initial experience with an environment influences the relative weighting of featural and geometric cues. Taken together, these results show that human adults use a flexible strategy for encoding spatial information.     

Allocation of effort as a function of payoffs for individual tasks in a multitasking environment

SYNWORK1 software allows the examination of how payoffs affect the allocation of effort by people when they perform four different tasks (memory search, arithmetic, visual monitoring, and auditory monitoring). In a previous study (Wang, Proctor, & Pick, 2007), we showed that participants adopted multitasking strategies allocating relative effort appropriate to payoff differences between the arithmetic and memory tasks, but that they exhibited residual effects of prior payoffs when the payoffs were switched. In the present study, we varied the payoff in two different experiments for only one of these tasks, the memory task in Experiment 1 and the arithmetic task in Experiment 2. Doing this allowed consideration of performance for both the task for which payoff changed explicitly and the other cognitive task, for which the payoff difference was implicit (i.e., relative to the explicit payoff that was manipulated). Although participants adjusted performance on the task for which the payoff explicitly varied, the payoff manipulation had less effect than did the explicit payoff manipulations for both tasks used previously. Also, the change in effort on a task resulting from explicitly increasing its payoff was less than that from decreasing the payoff. SYNWORK1 is a good environment for studying multitasking, but has several limitations that need to be addressed to provide a synthetic work environment that allows investigation of a wider range of theoretically relevant issues.