An investigation of patterns of respiratory behavior

Abstract

The study was an investigation into the existence and generalizability of individual patterns of breathing. Respiration recordings were obtained from eight male volunteer subjects while they performed a variety of experimental tasks. The subjects were paid for participating in the experiment and the amount each was paid depended upon relative performance scores in the experimental tasks. Subjects performed three tasks in each of six experimental sessions. Experimental sessions for a subject were scheduled on different days at approximately the same time of day. Twelve experimental tasks were employed and were classified into three different types: discrete (reaction-time and time-estimate tasks), continuous (tracking tasks), and cognitive (word-recognition tasks). Four of the tasks were repeated in separate experimental sessions. Pneumographic respiration records from each subject were normalized with respect to average peak-to-trough amplitude. The recordings were divided into a series of segments for each task. These record segments were then sorted by three female undergraduates who had been selected on the basis of previously demonstrated pattern-recognition capabilities to serve as judges. The categorical sortings of segments from all subjects were performed independently by judges for each experimental task. Although they received no information regarding the number of subjects involved or the specific tasks employed, the judges were highly successful in sorting segments from different subjects into categories containing segments from single subjects. Thus, the results indicated decisively that individual patterns of respiration do exist. Further, the findings extended across the experimental tasks. The possibility that differences in amplitude and rate of respiration could have accounted for the results was investigated and rejected. Instead, other characteristics were found in the records which appeared to have enabled judges to reliably distinguish between respiration patterns of different individuals. Judges also sorted categorically segments from all tasks for single subjects. Analysis of the sorting outcomes indicated that there was a tendency for breathing patterns to differ from one type of task to another. While these results were not striking, they did suggest that breathing behavior is influenced to some degree by certain task parameters. The findings of the present study were discussed with respect to alternative interpretations which could be offered. Implications of the results and directions for future research were also considered.