Senqi Hu

Asian Hypersusceptibility to Motion Sickness

A rotating optokinetic drum was used in three laboratory studies to test the hypothesis that Asian subjects are hypersusceptible to motion sickness. The results of the first study showed that Chinese women compared to European-American and African-American women experienced significantly more severe symptoms of motion sickness and greater disturbance of normal gastric myoelectric activity. A second study yielded similar results using American-born children of Asian parents. The results of a third study using Chinese men and women were similar and showed a significant increase in vasopressin during rotation. Possible genetic mechanisms that may account for these results are discussed.

Effects of Cold Stress on Gastric Myoelectric Activity

Cold stress inhibits gastric motor activity. The purpose of this study was to use the surface‐recorded electrogastrogram (EGG) to determine what characteristics of the gastric myoelectric activity accompany this decrease in gastric motor activity. Thirty fasted healthy male volunteers participated in the study. Twelve remained fasted and placed their hands in 4°C ice water (cold stress), 12 ate a meal and then underwent cold stress, and 6 control subjects ate and then put their hands in 30°C water. EGGs were recorded continuously during the 65‐minute session: 15 minutes of baseline, 20 minutes of cold stress, and 30 minutes of recovery. Cold stress significantly decreased the power of normal 3 cpm EGG activity in the fed subjects, whereas fasted subjects showed great variability in their responses including paradoxical increases in power. Control subjects showed no EGG responses to putting their hands in room‐temperature water. No subjects showed gastric tachyarrhythmia during cold stress. In conclusion, cold stress, a painful stimulus, but one not usually accompanied by nausea, attenuates the amplitude of normal 3 cpm gastric myoelectric activity in fed subjects, but does not provoke tachyarrhythmia.

Continuous Primary Nursing Care Increases Satisfaction with Nursing Care and Reduces Postpartum Problems for Hospitalized Pregnant Women

Abstract Objective: To compare the differences in practicing continuous primary nursing care (CPNC) versus task-centered nursing care (TCNC) with regard to patient satisfaction with nursing care and early postpartum health problems for hospitalized pregnant women. Design: All participants filled out the satisfaction with nursing care questionnaire, breastfeeding knowledge questionnaire, and early postpartum problem questionnaire. Setting: Participants in the CPNC group received continuous individualized primary nursing care and participants in the TCNC group received task-centered nursing care during their perinatal period. Participants: Using a randomized controlled trial, 470 hospitalized pregnant women participated in the study with 230 pregnant women in the CPNC group and 240 in TCNC group. Data Analysis: Questionnaire data were collected, calculated, and statistically analyzed using independent t-tests or χ2 tests along with power analysis. Results: Participants in the CPNC group reported significantly higher overall satisfaction with nursing care (t(468) = 5.936, p < .001), had more breastfeeding knowledge (t(468) = 5.633, p < .001), and were more likely to breast feed six weeks after delivery (χ2 (1) = 39.237, p < .001) than those in the TCNC group. Participants in the CPNC group also showed a significantly lower occurrence of postpartum urinary retention (Fisher exact test was used, p < .002) and breast discomfort (χ2 (3) = 34.482, p < .001) than those in the TCNC group. Conclusion: Practicing continuous primary nursing care was more effective than practicing traditional task-centered nursing care for hospitalized pregnant women in increasing satisfaction with nursing care, enhancing breastfeeding, and reducing early postpartum problems.

Effects of imagining eating favorable and unfavorable foods on gastric motility indexed by electrogastrographic (EGG) activities

The purpose of this study was to investigate the effects of imagining favorable or unfavorable foods on the amplitude of EGG recordings. 40 subjects were assigned to Favorable food and Unfavorable food groups in which they were asked to imagine eating a list of favorable foods or unfavorable foods. Subjects sat in a chair for 16 min. of baseline measurement prior to the 16 min. of food imagining. Electrogastrographic (EGG) activities were recorded continuously throughout. Using Fast Fourier Transform analysis, the spectral power of EGG activity of 3 cycles per minute (cpm) was calculated, and the ratios of EGG 3 cpm spectral power for the period of food imagining and baseline were obtained. The EGG amplitude at 3 cpm during imagining eating a list of unfavorable food was significantly lower than that of the baseline period and the EGG ratio between the food-imagining and baseline periods was significantly lower in the Unfavorable group than in the Favorable food group. It appears that imagining eating unfavorable food significantly inhibited gastric motility as indexed by decreased power of EGG activities at 3 cpm.

INVOLUNTARY AWARENESS AND IMPLICIT PRIMING: ROLE OF RETRIEVAL CONTEXT '

This study examined the role of retrieval context in implicit priming by manipulating percentage of word-stem index as shallow and deep processing while performing a word-stem completion task. 80 subjects were randomly divided into four groups each of 20 subjects: shallow processing or deep processing with few retrieval indices, and shallow processing or deep processing with many retrieval indices. Analysis indicated that proportion of word-stem completion was significantly higher for studied words than for nonstudied words in all four groups and that the subjects in the groups with many retrieval indices had a significantly increased proportion of word-stem completion between studied and nonstudied words than those in the groups with few retrieval indices. Postquestionnaire analysis indicated that more previously studied items were retrieved if many studied items were available during implicit word-stem completion and that only a small proportion of word-stem completion was finished with studied words by the subjects who were aware of the prior studied and test word relations in all four groups. It was concluded that having more studied words retrievable contributed to more being retrieved and that involuntary awareness had very limited influence on the priming in the implicit word-stem completion.

EFFECTS OF VIEWING PLEASANT AND UNPLEASANT PHOTOGRAPHS ON GASTRIC MOTILITY INDEXED BY ELECTROGASTROGRAPHIC (EGG) ACTIVITIES

32 subjects were randomly divided into Pleasant and Unpleasant groups depending upon whether the subjects viewed pleasant or unpleasant photographs. Subjects sat in a chair for 16 min. of baseline measurement prior to the 16 min. of photograph-viewing. The 16 subjects in the Pleasant group viewed a set of pleasant photographs. The 16 subjects in the Unpleasant group viewed a set of unpleasant photographs. Electrogastrographic (EGG) activities were recorded continuously throughout the baseline and photograph-viewing periods. The spectral power of EGG activity of 3 cycles per minute (cpm) was calculated. The ratios of EGG 3 cpm spectral power for the period of viewing photographs and baseline were then obtained. The statistical analysis indicated that the EGG amplitude at 3 cpm during the period of viewing unpleasant photographs was significantly lower than that of baseline period and that the EGG ratio between the photograph-viewing and baseline periods was significantly lower in the Unpleasant group than in the Pleasant group. In conclusion, viewing unpleasant photographs significantly inhibited gastric motility indexed by decreased power of EGG activities at 3 cpm.

Skin conductance as an indicator of anticipated concealed knowledge.

The present study investigated the effects of anticipation on skin conductance while participants were answering a set of questions which included one of concealed knowledge. Two experiments were conducted. In Exp. 1, 26 participants completed one experimental session. Each participant was asked to choose one two-digit number from 10 to 99 and was presented 19 other randomly generated two-digit numbers. The list of numbers was then presented to the participant on a computer screen, with a 60-sec. interval occurring every two questions. The participant-selected number was defined as the target question which was randomly placed within the 4th to 17th item of 20 questions stated as follows: “Is your selected number ____?” The participant was asked to answer “No” to all questions. The skin-conductance response to each question was measured. In Exp. 2, the experimental procedure was the same as that in Exp. 1 except each participant first answered 10 nontarget questions, then answered a target question with the participants selected number, and then answered another 10 nontarget questions. There were a total of 21 questions. Analysis indicated participants in both experiments generated the highest mean skin conductance while answering the target questions, followed by lower amplitudes to questions prior to and after the target question. The skin-conductance response pattern can be used to identify the psychological process of anticipation of concealed information.

Effects of Retention Intervals on the Magnitude of Optokinetic Rotation-Induced Taste Aversions

This study investigated the effects of different retention intervals on the magnitude of optokinetic rotation-induced conditioned taste aversions in humans. Two experiments were conducted. In Exp. 1, 20 subjects were divided into two groups, a CS-UCS group in which drinking soybean milk was paired with optokinetic rotation-induced gastric illness and a CS-Only group in which drinking soybean milk was not paired with optokinetic rotation. Analysis indicated that two days after pairing soybean milk drinking with optokinetic rotation, the subjects in the CS-UCS group had significantly reduced palatability ratings of soybean milk and lower consumption of soybean milk than those in the CS-Only group. In Exp. 2, 40 subjects were divided into four CS-UCS groups with 1-day, 3-day, 5-day, and 10-day retention intervals between the session of pairing soybean milk with optokinetic rotation and the session of retasting soybean milk. Analysis yielded no significant differences among four groups on palatability of soybean milk and consumption of soybean milk in the retasting session. It is concluded that optokinetic rotation is an effective unconditioned stimulus for conditioned taste aversions formation and that the aversion has a retention period of at least 10 days.