Eye movement indices of mental workload

Four investigations were carried out to assess the feasibility of using eye movement measures as indices of mental workload. In the first experiment, saccadic extent was measured during free viewing while subjects performed low, moderate and high complexity, auditory tone counting as the workload tasks. The range of saccadic extent decreased significantly as tone counting complexity (workload) was increased. In the second experiment the range of spontaneous saccades was measured under three levels of counting complexity with a visual task that did not require fixation or tracking. The results indicated that the extent of saccadic eye movements was significantly restricted as counting complexity increased. In the third experiment, the effects of practice were examined and decreased saccadic range under high tone counting complexity was observed even when significant increases in performance occurred with practice. Finally, in experiment 4, the first experiment was repeated with additional optokinetic stimulation and the saccadic range was again observed to decrease with tone counting complexity. The results indicated that the extent of spontaneous and elicited eye movements was significantly restricted as counting complexity increased. We conclude that this measure may provide a valuable index of mental workload.     

Conditioned reinforcement versus time to reinforcement in chain schedules.

Pigeons were trained on three-component chain schedules in which the initial component was either a fixed-interval or variable-interval schedule. The middle and terminal components were varied among fixed-interval fixed-interval, variable-interval variable-interval, and an interdependent variable-interval variable-interval schedule in which the sum of the durations of the two variable-interval components was always equal to the sum of the fixed-interval fixed-interval components. At issue was whether the response rate in the initial component was controlled by its time to primary reinforcement or by the temporal parameters of the stimulus correlated with the middle terminal link. The fixed-interval initial-link schedule maintained much lower response rates than the variable-interval initial-link schedule regardless of the schedules in the middle and terminal links. Nevertheless, the intervening schedules played some role: With fixed-interval schedules in the initial links, response rates were consistently highest with independent variable-interval schedules in the middle and terminal links and intermediate with the interdependent variable-interval schedules; these initial-link differences were predicted by the response rates in the middle link of the chain. With variable-interval schedules in the initial links, response rates were lowest with the fixed-interval fixed-interval schedules following the initial link and were not systematically different for the two types of variable-interval variable-interval schedules. The results suggest that time to reinforcement itself accounts for little if any variance in initial-link responding.     

Effects of word- and sentence-level contexts upon word recognition

In the present experiments, we investigated the facilitatory effects of auditorily presented prime words in neutral sentence contexts upon visually presented target words. It is shown that when the target task is a lexical decision, facilitation is obtained when the relationship between the prime and the target is one of synonymy (and low association strength). When instead the target is an antonym (again of low association strength), there is no priming effect; lexical decision is facilitated only when the prime word is presented in isolation. In further experiments, it is shown that primes in sentence contexts can produce facilitation of antonyms if they are strongly associated, or in the absence of association if the target must be named. The results are explained in terms of an integration process, which checks for the coherence between an upcoming word and the highest available level of representation of the context, but which affects only responses in the lexical decision task.     

An Attributional Analysis of Reactions to Magic Johnson1

Principles from attribution theory were used to analyze public reactions to the health status of Magic Johnson. An experimental study containing two distinct samples (college students and African-American adults) together with supplemental reports from local and national media confirm the value of this approach. The findings show that inferences about causal responsibility are related to affective reactions of sympathy and anger toward Magic Johnson. Implications for attribution theory, as well as for future attitudes toward Magic Johnson, are discussed.     

Molar versus local reinforcement probability as determinants of stimulus value.

During one component of a multiple schedule, pigeons were trained on a discrete-trial concurrent variable-interval variable-interval schedule in which one alternative had a high scheduled rate of reinforcement and the other a low scheduled rate of reinforcement. When the choice proportion between the alternatives matched their respective relative reinforcement frequencies, the obtained probabilities of reinforcement (reinforcer per peck) were approximately equal. In alternate components of the multiple schedule, a single response alternative was presented with an intermediate scheduled rate of reinforcement. During probe trials, each alternative of the concurrent schedule was paired with the constant alternative. The stimulus correlated with the high reinforcement rate was preferred over that with the intermediate rate, whereas the stimulus correlated with the intermediate rate of reinforcement was preferred over that correlated with the low rate of reinforcement. Preference on probe tests was thus determined by the scheduled rate of reinforcement. Other subjects were presented all three alternatives individually, but with a distribution of trial frequency and reinforcement probability similar to that produced by the choice patterns of the original subjects. Here, preferences on probe tests were determined by the obtained probabilities of reinforcement. Comparison of the two sets of results indicates that the availability of a choice alternative, even when not responded to, affects the preference for that alternative. The results imply that models of choice that invoke only obtained probability of reinforcement as the controlling variable (e.g., melioration) are inadequate.     

Cultural phenomena and the research enterprise: Toward a culturally anchored methodology

Highlights the points at which culture intersects major phases of the research enterprise — problem formulation, population definition, concept and measurement development, research design, methodology, and data analysis — and influences and constrains what researchers deem worthy of investigation and how they interpret what they observe. These ethnocentric biases inhibit the development of a knowledge base for understanding diverse cultural communities. At each step of the research process, the need to carefully examine and expose the underlying cultural assumptions and to generate and develop alternative choices is emphasized. Guidelines are provided to encourage researchers to be aware of and deliberately make choices toward the development of a culturally anchored methodology that balances the demands for rigor and sensitivity.     

EQUATING INVERSE PROBABILITIES IN IMPLICIT PERSONALITY JUDGMENTS

Abstract— Meehl and Rosen (1955) observed that their colleagues tended to equate the sensitivity of a sign (its probability given a diagnostic category) with its predictive accuracy (the probability of the diagnostic category given the sign). Such equating of inverse probabilities implies ignoring base rates. Later, many researchers demonstrated such neglect in a number of experimental contexts involving hypothetical judgments; others have found some use of base rates—but only when base rates were supplied by the experimenter, in which case even irrelevant base rates influenced judgment. The present study tested for equating conditional probabilities in a context similar to the contexts involved in the initial observations—that is, subjects strove for accuracy rather than attempted to make good judgments about hypothetical problems, and the base rates were generated by the subjects themselves. Neglect of base rates was revealed by within-individual comparisons showing subjects equated inverse probabilities without equating the corresponding unconditional ones.     

The NCATE Process and behaviorally-based special education

The National Council for Accreditation of Teacher Education (NCATE) has long sought to identify effective programs for teacher preparation in this country. Recently, the Council has revised its standards to be more rigorous and demanding. This revision presents new and challenging standards for the accreditation of programs preparing educators. The most problematic but most important of these new standards is the requirement of a well-articulated knowledge base supporting a program's content and processes. Development of the knowledge base statement involves the articulation of the program's philosophy, theme, model, goals, objectives, primary research base, wisdom of practice, and evaluation procedures. A behavioral model serves well in meeting these requirements, particularly since behavioral applications in education are well researched and the approach is compatible with the emphasis on specific goals and objectives and evaluation of effectiveness. Effective educational methods are available and are mostly behavioral. The articulation of the NCATE knowledge base encourages education faculty, traditionally nonbehavioral, to examine the effectiveness of their programs and to demonstrate research and professional support for content and instructional methods. A behavioral knowledge base statement appropriate for NCATE is demonstrated through examples drawn from Gonzaga University's knowledge base for special education.