The effect of light intensity when onset or termination of illumination is used as reinforcing stimulus

The Psychological Record - Two experiments were performed to examine the reinforcing effects of onset and termination of non-aversive illumination, made conterminous with lever contacting, as a...     

Contrasting speech patterns in apraxia of speech and phonemic paraphasia

This study was designed to determine if perceptual phonological analysis would reveal distinctions between patients with apraxia of speech and patients with phonemic paraphasic speech. Test findings from 10 Broca's aphasics with apraxia of speech were compared to findings from 10 paraphasic speakers (5 conduction and 5 Wernicke's aphasics). Several marked differences were revealed. Predominant locus of errors and relative difficulty of different classes of phonemic segments were significant discriminators. There was a nonsignificant trend for substituted phonemes to be further from target phonetically in the paraphasic patients. In addition, the two groups showed certain consistent differences in the types of errors they produced. Apraxic patients produced many errors of transitionalization, while sequencing errors were more typical of the patients with phonemic paraphasia. The findings are interpreted in relation to a neuropsychological model of speech. It is suggested that phonemic paraphasia represents a breakdown mainly in the retrieval of phonological word patterns, while apraxia of speech is characterized predominantly by a disturbance in encoding phonological patterns into appropriate speech movements.     

Infant state in relation to its environmental context

Two neonatal intensive care units (NICU) were observed every 15 minutes for at least 72 consecutive hours. Although infants on both NICUs were exposed to considerable amounts of stimulation, there were differences between the units for each environmental measure in the amount of stimulation and/or the pattern of circadian periodicity. The two NICUs also differed in the amount of time infants spent in various states and in the pattern of state periodicity. In general, the diurnal rhythms of the infant states were associated with the diurnal rhythms of different environmental events; furthermore, the patterns of association were not the same on the two NICUs. The results point to potential problems in depicting a “typical” NICU. More importantly, they suggest that the environmental of NICUs has a recognizable influence on aspects of their inhabitants' behavior and that the nature of influence is different from NICU to NICU. The effects are potentially significant for physical, social, and cognitive development.     

Aviator performance in week-long extended flight operations in a helicopter simulator

Psychological, physiological, and biochemical correlates of aviator crew performance, stress, and fatigue were measured in a week-long flight schedule in a helicopter simulator. Three two-man crews of rotary wing aviators performed 14 h of precision instrument flight on each of 4 successive days and 10 h on the 5th day. Missions involved repetitions of 2-h standardized day and night flight profiles that were occasionally interrupted by simulated emergencies. Aviator performance measures included meeting assigned airspeeds, altitudes, headings, turn rates, and navigation requirements. Pilots slept 4 h each night. Baseline data were collected prior to, and recovery data after, the extended flight schedule. Pilots maintained simulator flight parameters to within acceptable tolerances of assigned headings, airspeeds, and altitudes, even into the morning of the 4th day of the schedule. However, cognitive and judgmental errors were made. Even though flight surgeons deemed them unsafe to fly by the 3rd night, pilots continued to fly well to the 5th day.