One-minute Trials Research Articles

Language, play and work among elderly persons

The general purpose of the study was to ascertain the meanings of play and work among elderly subjects. Subjects were randomly assigned either play or work as stimulus words and asked to write down other words they associated with the stimulus word during a one-minute trial. Results suggested that play and work were different ideas for the group of elderly subjects. Play was best defined as an enjoyable, voluntary activity often associated with a younger period in the life cycle by the subjects. Work was best defined as a required activity that few seemed to enjoy. Work was also characterized as demanding and associated with an occupational role, extrinsically motivated, and producing a considerable awareness of time. Gender difference in the meanings of play were not remarkable. Men were somewhat more likely to define play as a formal sport and outdoor related activity. Women's definitions were best distinguished by a preference for culturally oriented responses.

Attention and habituation: Separation of specific components in development

In four experiments using habituation procedures, it was shown that selective investigation of stimuli that are novel gradually developed between 13 and 28 days of age in gerbil pups. The youngest pups investigated the stimuli, but were highly variable in their responses to an object or to odors of conspecifics. Habituation could, but did not reliably, occur. By 21 days of age, investigation of a cup attenuated in a series of 5 one-minute trials and responses increased after the cup was moved to a new location. By 28 days of age, reliable habituation was shown 24 hours after a one-minute exposure to a cup. The data were used to infer how an immature process of selective attention may be responsible for variability in expression of habituation during development.

EEG coherence and power changes during a continuous movement task

EEG coherence (COH) is a mathematically derived measure of the time- and frequency-related similarities between a pair of EEG channels. In this report, COH was measured during an externally verified motor task in which the areas of cortical involvement are known, with special consideration given to procedural and artifactual issues. Fourteen right-handed women (ages 18–39, x̄ = 26.7 years) were instructed to alternate continuously between fist-clenching and finger extension of the right hand, left hand, both hands, or neither hand (rest condition) in a counter-balanced sequence (4 one-minute trials for each condition; 16 total minutes). One minute each of intentional eye-movement (EOG) and intentional facial muscle tension (EMG) was recorded for artifact assessment. Eight channels of eyes-closed EEG were recorded from Fp1, Fp2, F3, F4, C3, C4, P3 and P4, each referenced to the ipsilateral earlobe. FFT spectral power analyses were conducted on 8 EEG channels and COH analyses (percentage of seconds/minute in which COH ⩾ 0.80) were performed on 16 pairs of leads: 4 interhemispheric, 6 intrahemispheric (left) and 6 intrahemispheric (right). COH measures increased during hand movement conditions, especially in the 9–12 Hz range, and were most apparent from prefrontal, premotor and motor areas. Parietal sources were essentially unchanged. Power measures were unchanged for virtually all leads and conditions. Increases in COH were not due to EOG or EMG artifact contamination. Evidence for lateralized increases was equivocal; significant bilateral increases were observed more often regardless of the hand clenched. Implications and suggested areas for future research are discussed.

Aortic and right atrial pressures during standard and simultaneous compression and ventilation cpr in human beings

Coronary perfusion pressure, as reflected by the diastolic aortic to right atrial (Ao-RA) pressure gradient, has been shown to correlate well with coronary blood flow during standard external CPR (SE-CPR) and is an important determinant of successful cardiac resuscitation. Few studies have documented such Ao-RA gradients in human beings, however. Twenty patients sustaining out-of-hospital cardiopulmonary arrests and basic cardiac life support were instrumented with thoracic aortic and right atrial catheters on arrival in the emergency department. The mean time from arrival in the ED to catheter placement was 16.5 +/- 6.0 minutes. With SE-CPR, peak systolic aortic and right atrial pressures were 73.7 +/- 20.2 mm Hg and 69.6 +/- 18.3 mm Hg, respectively. End diastolic aortic and right atrial pressures were 27.9 +/- 7.3 mm Hg and 20.3 +/- 7.2 mm Hg, respectively, with an end diastolic gradient of 7.9 +/- 9.1 mm Hg. Three patients had systolic Ao-RA gradients of more than 25 mm Hg, which is consistent with some cardiac compression as a mechanism of flow. Five patients also had one-minute trials of simultaneous compression and ventilation CPR (SCV-CPR). Ao-RA end diastolic gradients decreased in four of the five during SCV-CPR. No patient in this study was resuscitated successfully. We conclude that ED SE-CPR provides little coronary perfusion for victims of prehospital cardiac arrest. Although SCV-CPR has been shown to improve carotid blood flow in human beings, it appears to have an adverse effect on the already minimal myocardial perfusion provided by SE-CPR.

TEMPORAL DISTRIBUTIONS OF RESPONDING DURING DISCRETE‐TRIAL OMISSION TRAINING IN RATS

Within-session temporal distributions of responding were investigated in three experiments using rats pressing a lever in a discrete-trial omission procedure. This schedule entailed 60, one-minute trials, and a sucrose solution was made available at the end of each trial in which no lever press occurred. In Experiment I, nonnaive rats acquired and maintained responding during this training. Moreover, the probability of a response during any session showed a strong and reliable tendency to increase from the beginning to the end of the session. These results were replicated in Experiment II, using naive animals. In Experiment III, alterations were made in the training procedure, including elimination of response-contingent and noncontingent stimulus changes. Results indicate that stimulus change may be sufficient to maintain low levels of responding whether or not this change is contingent on responding.

Respiratory tracking of dichotically presented tonal amplitudes.

This study investigated the possible existence of a lateralized auditory sensorimotor integration system between amplitude modulations of a tone and respiratory movements controlling them. A dichotic pursuit auditory tracking paradigm was utilized that has previously implicated a lateralized sensorimotor system for lingual and mandibular control of frequency modulated acoustic stimuli. Thirty-two normal right-handed subjects tracked a continuously varying pure tone, the target, randomly fluctuating from 65 to 95 dB SPL, and presented to one ear, with another tone, the cursor, controlled by inhalation/exhalation movements (lung volume changes) and presented to the other ear. Target and cursor tones were counterbalanced for right and left ear presentation across 40 one-minute trials. Results failed to show a statistically significant laterality effect. Significant interactions revealed an advantage for cursor/RE, target/LE laterality presentation during the second half of each 20-trial block, and a predominant within trial REA. Tracking efficiency was far below that observed for upper articulator control of the cursor. A tentative conclusion is that the particular subpart of the speech musculature used in the tracking paradigm is more relevant to a lateralized sensorimotor integration system than the compliance between the sensory result of the movement, re: speech production and the movement pattern itself.

An Operational Analysis of a Continuous Ball Throwing and Catching Task

An operational analysis was carried out on a continuous ball throwing and catching task during the course of ten practice sessions composed of five one-minute trials with one-minute interpolated rest intervals. Subjects were ten male students (18-21 years) with varying degrees of sophistication in ball games. Group analysis showed a decrease in the amount of time the ball was watched while it was in flight as sessions proceeded. This result was paralleled by an increase in the amount of time before the ball reached the hand that the eyes transferred from ball to target. Results for the amount of time the ball was held from session to session were shown to fit an exponential model. Attention is drawn both to overall variance and individual differences within the composite model. Suggestions are made for further developments.