Electrooculographic indices of changes in simulated flying performance

Recent investigations have revealed statistically reliable relationships between signal detection by human subjects performing vigilance tasks and changes in the electrophysiologically recorded waveform of the eyeblink. Thus, this relatively simple and easy-to-obtain measure may have potential use as a predictor of impaired performance. This report describes a study in which eyeblink data were recorded on analog tape while subjects (instrument-rated pilots) “flew” a computer-generated flight plan in a General Aviation Trainer (GAT-1). Eyeblink data were reduced and scored with an adaptation of software from the Washington University Behavioral Research Laboratory. Subjects’ “flying” performance was evaluated with the Pilot Performance Evaluating System (PPES) implemented on a Digital Equipment Corporation (DEC), PDP-11/34 computer. The PPES samples each of four primary flight instruments once per second. It scores performance by generating a combined error score for each maneuver it assigns on the flight-plan display in the cockpit. The PPES/GAT-1 linkup has proved to be a valuable research tool with which to realistically evaluate stress effects and physiological correlates of flying performance in a laboratory setting. This study examined the relationships between eyeblink and flying performance scores collected during a pilot-fatigue study. Analysis of the data supports the use of computers cored eye movement measures as predictors of flying performance decrements.     

Energy Processing Characteristics of Spatial Vision: The Spectral Characteristics of Perceptive Fields

To this stage a large amount of information has accumulated on one-dimensional broadband frequency channel characteristics of the visual system. Only recently have attempts been made to define additional two-dimensional narrow-band response profiles-particularly in central vision. In this paper questions concerning the number, tuning widths and phase sensitivity of such two-dimensional narrow-band coding units are reviewed. Results with grating and two-dimensional images are discussed, particularly within the context of energy processing and information reduction strategies which reflect human performance. Finally, a consequent principle of univariance is defined and shown to hold with such filter units.     

The effects of stimulus familiarization on patterns of visual selection

Patterns of visual selection were recorded as Ss viewed pairs of stimulus drawings in which the two members were either both incongruous or both banal. Prior to presenting the paired stimuli, S was preexposed to either one member of the stimulus pair or to the incongruous or banal counterpart of one member of the stimulus pair. The results indicate that: (1) preexposure to a stimulus reduced its potential to elicit looking responses, and the magnitude of that reduction was greater for incongruous stimuli than for banal stimuli; (2) preexposure to an incongruous stimulus affected the potential of its banal counterpart to elicit looking responses, but preexposure to a banal stimulus did not affect the potential of its incongruous counterpart to elicit similar responses; and (3) the reduced potential of the preexposed member of a stimulus pair to elicit looking responses waned after 10 sec. These results were discussed in light of an “information-conflict resolution” model of visual selection.     

Recording puff volume in smoking

Recent research on nicotine self-administration has highlighted the need to accurately assess within-cigarette topography in order to estimate changes in puff profiles that occur in response to varying nicotine content. This paper describes equipment and techniques that may be used to record puff volume in the laboratory and discusses methods used by other researchers to study puff volume with an emphasis on methodological advantages of the present technique.     

participating in a couples therapy outcome study: Participants' views

Discovering that participants who received therapy in a research project and were being debriefed in a therapy outcome study considered those assessment sessions therapeutic, the authors conclude that participants: (a) are aware of the research context, (b) have some idea about how it affected the treatment they got, and (c) see positive outcomes for taking part in the study. Assessment and treatment were not separated in the minds of some participants, as they had been in the mind of the researchers.This study was supported in part by National Institute on Drug Abuse grant #1R 18DA 1069232001.     

Multilevel covariance structure analysis of sibling substance use and intrafamily conflict

Conventional covariance structure analysis, such as factor analysis, is often applied to data that are obtained in a hierarchical fashion, such as siblings observed within families. A more appropriate specification is demonstrated which explicitly models the within-level and between-level covariance matrices of sibling substance use and intrafamily conflict. Participants were 267 target adolescents (mean age=13.11 years) and 318 siblings (mean age=15.03 years). The level of homogeneity within sibling clusters, and heterogeneity among families, was sufficient to conduct a multilevel covariance structure analysis (MCA). Parental and family-level variables consisting of marital status, socioeconomic status, marital discord, parent use, and modeling of substances were used to explain heterogeneity among families. Marital discord predicted intrafamily conflict, and parent marital status and modeling of substances predicted sibling substance use. Advantages and uses of hierarchical designs and conventional covariance structure software for multilevel data are discussed.