Mass estimation and discrimination during brief periods of zero gravity

Under zero gravity, the gravitational cues to mass are removed, but the inertial cues remain. A sensation of heaviness is generated if objects are shaken, and hence given a changing acceleration. A magnitude estimation experiment was conducted during the 0-G phase of parabolic flight and on the ground, and the results suggested that objects felt lighter under 0 G than under 1 G. Mass discrimination was also measured in flight, and yielded Weber fractions of .18 under 0 G, .16 under 1.8 G, and .09 under I G. Poor performance under microgravity and macrogravity was probably due mainly to lack of time for adaptation to changed G levels. It is predicted that discrimination should improve during the course of prolonged spaceflight, and that there should be an aftereffect of poor discrimination on return to earth.     

Children's use ofGet passives

Children's use ofget in passivelike constructions was examined in this study. Fifty-eight children at three age levels were tested twice on imitation, comprehension, and production tasks. For the imitation and comprehension tasks, passive sentences withget were modeled in one instance and withbe in the other instance. On both tasks, children performed significantly better on theget items than on thebe items. For the production tasks, active sentences were used as the experimental stimuli. Among 928 production responses possible, children produced 423get passives and 6be passives. The frequency ofget passives increased with increasing age. Qualitative analyses were performed to determine agerelated changes in the pattern of linguistic strategies chosen. These data were consistent with predictions derived from a model of lexical directionality: Children used moreget thanbe passives and more truncated than full passives.     

Microcomputer-based estimation of psychophysical thresholds: The Best PEST

A new, maximally efficient technique for measuring psychophysical thresholds (Pentland, 1980) has been implemented on the microcomputer. This PEST (parameter estimation by sequential testing) technique is the most efficient sequential parameter estimation technique possible, given that the form of the psychometric function is known. The technique is similar to but faster and more accurate than other staircase procedures and may be applied whenever staircase techniques are applicable. The “Best PEST” is easily implemented on the micro-computer; a BASIC program for the Apple II which does so is presented. The Best PEST is compared with other staircase procedures, including one recently implemented on a micro-computer (Corwin, Kintz, & Beaty, 1979).     

Converging evidence for the role of relative timing in speech

In an earlier article (Tuller, Kelso, & Harris, 1982a) we suggested that the timing of consonant-related muscle activity was constrained relative to the period between onsets of muscle activity for successive vowels. Here, we reexamine those data based on reservations posed by Barry (1983). Next, we present a kinematic study of articulation that extends and strongly supports our original observations. Finally, we very briefly survey some converging lines of evidence for a functionally significant vowel-to-vowel period in speech and how this may relate to the role of temporal invariance in motor skills in general.     

Input/output switch in bilingual code switching

Chinese-English bilinguals were asked to read a passage with spontaneous bilingual code switchings, compared with a unilingual Chinese translation of the passage, a unilingual English translation, a translation with random switchings, and a translation with only nouns switched into English. There was no difference between the reading speed for the passage with natural switchings and the unilingual Chinese passage, thus questioning the need to postulate a bilingual imput/output switch. The speed for reading passages with artificial switchings was slower. In a translation task, the naturally switched items required less time in Chinese-to-English translations compared with English-to-Chinese translations. This indicates that in natural code switchings, the English lexical items produced were more available, even though English is generally the weaker language.     

A self-contained mental health outpost: An automated approach to prevention

This paper describes the application of a microcomputer system as a mental health outpost. The outpost contains a psychological screening inventory, a relaxation training and educational session, and a consumer-satisfaction questionnaire. A study to assess the validity of the decision making algorithm of the mental health outpost is reported. The implications of an automated delivery system for first-level preventive and promotional mental health services are discussed.     

On quantitative reviewing1

Cook and Leviton (1980) recently discussed the merits and disadvantages of quantitative literature reviewing. They apparently view the method with favor, but they also noted that several shortcomings may result from the method itself. It is argued that these particular deficiencies are unrelated to the method, and instead are attributable to poor reviewer practices. These issues are examined in an effort to avert any undue hesitancy on the part of future reviewers to quantify their efforts.     

Comprehension of gerundive constructions by Broca's aphasics

Eleven diagnosed Broca's aphasics were tested for comprehension of sentences containing gerundive constructions. Results showed that, as a group, these patients were sensitive to grammatical distinctions signaled by “function” words, contrary to the predictions of some current theories about the specific deficits exhibited in this syndrome. Further analysis showed that the patients fell into two subgroups, one which exhibited sensitivity to the distinctions in normal grammar, and another which exhibited no sensitivity to such distinctions. This suggests that the syndrome may have different manifestations in different populations—patient age is suggested as a possible means for distinguishing the two groups. Suggestions for further research into the nature of the comprehension deficits exhibited by Broca's aphasics are made.