Utility maximization and melioration: Internalities in individual choice

How do people go about choosing between alternatives in relatively simple settings? This study explores some of the variables that past work suggests may be relevant. Volunteer subjects worked for money in six procedures in which the probability of a payment from either of two alternatives was 1.0, but the rate of pay (i.e. the speed with which a payment was delivered or the size of the payment) interacted with the subjects recent allocation of choices, which we define as the ‘internalities’. Because of the internalities, choosing the currently more profitable alternative did not maximize total earnings. Subjects were more likely to fail to maximize when the interaction between present pay and past choices was spread over longer sequences of choices, or when the reward variable was the speed, rather than the value, of each payment. Subjects often disregarded the internalities and were instead guided by the current yields of the two alternatives, which is a frequently observed tendency, called ‘melioration’, in experiments on choices by animals. The tendency toward melioration was only partially counteracted by explicit instructions on how to maximize earnings. We discuss a theoretical framework for melioration that postulates both motivational and cognitive sources.     

Time-stamping computer events to report .1-msec accuracy of events in the Micro Experimental Laboratory

A critical problem in most real-time programming tasks is the verification that timing of the presented displays and recorded events occur at the expected times. It is often difficult for psychologists to verify critical timing because of the lack of costly specialized tools and technicians to measure events with millisecond accuracy. Algorithms utilized in a new Time Audit mechanism, added to the Micro Experimental Laboratory, are described. This new mechanism involves the recording and time stamping of all input and output events with 0.1-msec accuracy. This allows the experimenter to determine the initiation, duration, and termination of each event and also makes it possible to relate these events to the synchronization of the screen refresh cycle. A customized user interface provides a time log and event-tracing feature that enables nonprogrammers to determine the duration of command execution to the .1-msec level, allowing rapid, precise assessment of program execution. The resulting time log provides a detailed specification of the experimental events for debugging and a permanent record of the experimental procedure.     

Limits of focused attention in three-dimensional space

The present experiment examined the shape of the attentional gradient in three-dimensional space. Subjects performed a response-compatibility task in which they were instructed to respond to a centrally located target and ignore flanking distractors. The irrelevant distractors were presented at combinations of seven different depths, three different horizontal separations, and three different vertical separations relative to the target. Depth was varied in a stereoscopic display viewed through polarized glasses. Overall, the size of the response-compatibility effect decreased with increased separation in all three dimensions. Interestingly, the response-compatibility effect was larger for horizontal separations than for vertical separations and was larger for crossed disparities than for uncrossed disparities. The results suggest an elliptical focus of attention, with steeper gradients in the vertical dimensions than in the horizontal dimensions. In addition, the results suggest, along the vertical dimension, a steeper gradient for objects located beyond the focus of attention relative to that for objects located between the observer and the focus of attention.     

Mental image reversal and verbal recoding: When ducks become rabbits

A recent debate has concerned whether classical bistable configurations (e.g., duck/rabbit) can be reinterpreted using mental imagery. Research in this field indicates that image reversal is possible only when subjects change their specification of orientation. In a series of four experiments, we demonstrate that mental reversal of classical bistable configurations( CBCs) is impeded by verbally recoding the visual pattern at the time of input. When subjects were prevented from verbally recoding visual stimuli in short-term memory, they fared systematically better in mentally reversing the CBC, even when they received no instructions to change their reference frame or specification of orientation. On this basis, we suggest a model of image reversal that takes into account the interaction between memory codes and provides a new perspective on verbal recoding, verbal overshadowing, and mental discoveries.     

Rate variables and automatized naming in developmental dyslexia

The rate variable in rapid automatized naming (RAN) was investigated in 50 adolescent and 40 adult students with developmental dyslexia, in matched normal controls, and in learning-disabled students without reading difficulties. Visual stimuli depicting familiar colors and common objects were presented in isolation at three film speeds and three exposure times. Film speed and exposure time contributed as independent variables to error rate; and dyslexic subjects of both age groups made significantly more naming errors than controls. Dyslexic subjects also responded with longer naming latencies than controls when the same RAN stimuli were presented in a continuous sequential mode as a matrix of rows and columns. Naming latencies in the sequential presentation were highly correlated with naming errors in the film version. The implications of reduced naming rates for nongraphological stimuli in developmental dyslexia are discussed.     

Maladjustment in statistical minorities within ethnically unbalanced classrooms

Ascertained if being a member of a statistical minority influences children's adjustment in school, as measured by the AML, a teacher-administered adjustment rating scale. Teachers from a southwest school district evaluated elementary students on aggressive, acting-out behaviors, moody-internalized behaviors, and learning difficulties. Analyses conducted on 376 students revealed significant effects of statistical minority status on certain dimensions of adjustment ratings for both Hispanic and Anglo students. Hispanic students in the statistical minority received poorer ratings on the moodiness dimension of the AML than nonminority Hispanic students. Anglo students in the statistical minority received poorer ratings on the aggression dimension of the AML than nonminority Anglo students. These results were interpreted in terms of cultural differences in coping with statistical minority status. Traits commonly exhibited within a culture may intensify and be perceived as maladaptive when stress resulting from being a minority occurs. Implications of the finding that statistical minority status within the school environment influences adjustment are discussed.     

Sources of difficulty in deductive reasoning: The THOG task

The THOG task presents four designs constructed from two shapes and two colours. Subjects are told that the experimenter has written down one of the shapes and one of the colours and are provided the rule that if, and only if, any design has either the shape or the colour, but not both, written down, then it is a THOG. Finally, they are given an exemplar and are asked to classify the remaining designs. Successful solution requires construction of hypotheses, reasoning under each hypothesis, and comparison of the results under each to reach a final conclusion. Few subjects are able to provide adequate responses on the standard version of the task. We present the results of four experiments, with 160 undergraduates each presented with one of eight versions of the task. Experiments 1 and 2 indicate that (1) some subjects think that the properties that are written down are identical to those of the exemplar, although these are not the same subjects who exhibit the modal error pattern, (2) many subjects correctly understand the disjunction of the rule but fail to consider the hypotheses, and (3) poor initial encoding of the problem is not easily corrected. Experiment 3 investigates the sufficiency of the claim of Griggs and Newstead (1982) that appropriate problem solution follows from explicit presentation of all problem information (including use of positive labels for properties that are not written down), and Experiment 4 investigates the necessity of the claim. The results of Experiments 3 and 4 show that presenting positive category labels does increase the frequency of correct solution; however, positive category labels are not necessary for such improvement. Separation of the labels of the THOG rule from those of the exemplar, or informing subjects that only one other design is a THOG, also increases the frequency of successful solution. The results suggest that many people have some fairly sophisticated reasoning skills. but application of these skills is easily discouraged when the features of the task lead to poor initial encoding.