An introduction to the UCSD PASCAL system

This paper provides an introduction to the UCSD PASCAL system: a nearly machine-independent software system for micro- and minicomputers. The system is designed to run as a single-user interactive system. It is written almost entirely in the PASCAL programming language and consists of: a single-user operating system, PASCAL pseudomachine interpreter, PASCAL compiler, screen- and line-oriented editors, file manager, debugger, utility programs, and a BASIC compiler. A CAI package is also available.     

The advantages of 16-bit microcomputers

Microcomputers have great applicability for psychological laboratories. While it is usual to limit discussions of microcomputers to 8-bit equipment, 16-bit machines have several advantages. In many situations, these systems prove to be more efficient and cost effective.     

A technique for converting from intravenous drug self-administration to liquid reinforcement

A rapid inexpensive technique for changing from intravenous drug self-administration (DSA) to liquid reinforcement is described. Utilizing a standard peristaltic-type infusion pump typically used in DSA experiments and a specially designed drinking cup, the changeover from intravenous DSA to liquid reinforcement can be accomplished in a few minutes at a cost of less than $10.     

The role of proprioception in the perception and control of human movement: Toward a theoretical reassessment

The theoretical role of proprioception in the perception and control of human movement is elusive because of the obvious inability to manipulate experimentally the various receptive systems. Individuals who have had the metacarpophalangeal joint and joint capsule removed and replaced with silastic inserts afford a unique opportunity to evaluate a principal source of proprioception, namely, slowly adapting joint afferents. In a set of experiments, we show that such individuals show no deficits in finger localization following joint replacement. We take this and other complementary findings as a preliminary basis for proposing a dynamic rather than kinematic account of movement production. In addition, we provide a reconceptualization of the function of proprioceptive information in the CNS. Our arguments focus on proprioceptive inputs as tuning or modulating interneuronal pools rather than providing dimension-pecific information to the brain, as is commonly assumed.     

A set-theoretic random utility model of choice behavior

A random utility model of choice was developed by combining the basic ideas of the well-known theories of Thurstone and Restle. The new model has exactly the same number of free parameters as Tversky's Elimination-by-Aspects model. Furthermore, both models were found to fit, with equal accuracy, the data reported by Rumelhart and Greeno, and Tversky. It was concluded that although the two theories are not identical, they may be difficult to discriminate empirically.     

Validity of teacher nominations of child behavior problems

The purpose of this study was to examine the validity of teachers' identification of problem children. Ninety-five third-grade children served as subjects. Teachers nominated children as a conduct problem, withdrawal problem, or normal, resulting in 16, 14, and 65 children being assigned to the three groups. Behavioral observations, peer sociometric ratings, and academic achievement scores were collected. The results indicated that conduct problem children differed from normal children on behavioral, sociometric, and academic measures, whereas withdrawn children differed from normals on the latter two measures. Conduct problem and withdrawal problem children did not differ on any of the dependent measures. The results suggest that teachers can identify children who are having difficulties in class but may be less accurate in differentiating between different types of problem children.This research was supported in part by NIMH grant MH-28859-01. Data reported in this article are part of a larger project assessing the social skills of children.     

Parafoveal information is not sufficient to produce semantic or visual priming

Marcel (1978) has shown that semantic priming can occur in the lexical-decision task even if the prime is masked to the point at which its presence cannot be detected. The purpose of the present experiments was to determine if primes that begin four or five spaces to the right of fixation can also produce semantic facilitation even though they are very difficult to recognize. Experiment 1 showed that facilitation did occur when the parafoveal primes used in the subsequent experiments were presented foveally. In Experiment 2, the primes were moved to the parafovea, but the task demands directed the subject’s attention toward the fovea. When subjects were ignoring the information presented to the parafovea (an allocation pattern that should correspond to that used during normal reading), neutral primes were just as effective as either semantically related or identical primes. In Experiment 3, the task demands were altered so that subjects were actively attending to the parafoveal primes. Although subjects were trying to process the primes, there was still no evidence that benefits could be derived from parafoveal primes. A final experiment showed that subjects given extensive practice with the materials will produce large amounts of identity and semantic priming. The results support the conclusion that readers can benefit little from the preprocessing of information in the parafovea unless that information can be supplemented with contextual expectations.