Is sweetness taste enhancement cognitively impenetrable? Effects of exposure, training and knowledge.
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Analysis of Variance↗
Biomedical subjects
R J Stevenson
Publications and source records attributed to R J Stevenson.
Differences in naming accuracy of odors presented to the left and right nostrils.
Two interlinked areas of debate within psychology are the existence of hemispheric specialization for olfactory processing and whether odors are processed primarily as perceptual codes or as a set of semantic features. This study compared accuracy in naming and judgments of familiarity by right handed subjects to common odors that were presented to the left or right nostrils. There was significantly better production of the correct name of the odor after left side presentation, than after right. Familiarity ratings were identical.
Adult↗
The acquisition of odour qualities.
Odours can evoke a large range of qualities. Some of these qualities (e.g., sweetness) appear to be acquired through simultaneously experiencing odours mixed with tastes. Acquisition might also occur when two odours are experienced as a mixture. In this case mixture components might acquire each other's qualities. This was tested in two experiments. In the first, subjects repeatedly sniffed two odour mixtures (either AX, BY or AY, BX). Odours mixed with A acquired A's properties and were judged more similar to A than to B. Odours mixed with B were not clearly discriminable. The second experiment used a similar approach except that Odour B was replaced. Subjects now smelled either AX, CY or AY, CX. All components were discriminable. Odours mixed with A acquired A's properties and were judged more similar to A than to C. Although odours mixed with C did not acquire C's qualities due to a confusion of quality terms, odours previously mixed with C were judged as more similar to C than to A. Evidence of other quality exchanges were also obtained. These results suggest that pure odour qualities can be learnt and lend support to William James's (1890) notion of the acquired equivalence/distinctiveness of cues.
Adult↗
Perceptual learning with odors: implications for psychological accounts of odor quality perception.
After two odors have been experienced in a mixture, the pair are subsequently rated as sharing more qualities and smelling more alike than equally exposed controls. These effects may result from the retrieval of a common mixture memory when either component is sniffed alone. If correct, odor pairs experienced together in a mixture should also be less discriminable than those experienced an equal number of times but in different mixtures. This was tested here by exposing participants to two odor mixtures (either AX, BY or AY, BX) and then testing their ability to discriminate between the components. As predicted, odors previously experienced together as a mixture were less discriminable than controls. These and related findings noted above suggest that learning and memory play an important role in odor quality perception.
Adult↗
Resistance to extinction of conditioned odor perceptions: evaluative conditioning is not unique.
A tasteless odor will smell sweeter after being sampled by mouth with sucrose and will smell sourer after being sampled with citric acid. This tasty-smell effect was found in experiments that compared odor-taste and color-taste pairings. Using odors and colors with minimal taste (Experiment 1), the authors found that repeated experience of odor-taste mixtures produced conditioned changes in odor qualities that were unaffected by intermixed color-taste trials (Experiment 2). An extinction procedure, consisting of postconditioning presentations of the odor in water, had no detectable effect on the changed perception of an odor (Experiments 3 and 4). In contrast, this procedure altered judgments about the expected taste of colored solutions. Evaluative conditioning (conditioned changes in liking) is claimed to be resistant to extinction. However, these results suggest that resistance to extinction in odors is related to the way they are encoded rather than to their hedonic properties.
Adult↗
Frequency of blood glucose monitoring in relation to glycaemic control: observational study with diabetes database.
OBJECTIVES: To investigate patterns of self monitoring of blood glucose concentration in diabetic patients who use insulin and to determine whether frequency of self monitoring is related to glycaemic control. SETTING: Diabetes database, Tayside, Scotland. SUBJECTS: Patients resident in Tayside in 1993-5 who were using insulin and were registered on the database and diagnosed with insulin dependent (type 1) or non-insulin dependent (type 2) diabetes before 1993. MAIN OUTCOME MEASURES: Number of glucose monitoring reagent strips dispensed (reagent strip uptake) derived from records of prescriptions. First recorded haemoglobin A1c concentration in the study period, and reagent strips dispensed in the previous 6 months. RESULTS: Among 807 patients with type 1 diabetes, 128 (16%) did not redeem any prescriptions for glucose monitoring reagent strips in the 3 year study period. Only 161 (20%) redeemed prescriptions for enough reagent strips to test glucose daily. The corresponding figures for the 790 patients with type 2 diabetes who used insulin were 162 (21%; no strips) and 131 (17%; daily tests). Reagent strip uptake was influenced both by age and by deprivation category. There was a direct relation between uptake and glycaemic control for 258 patients (with recorded haemoglobin A1c concentrations) with type 1 diabetes. In a linear regression model the decrease in haemoglobin A1c concentration for every extra 180 reagent strips dispensed was 0.7%. For the 290 patients with type 2 diabetes who used insulin there was no such relation. CONCLUSIONS: Self monitoring of blood glucose concentration is associated with improved glycaemic control in patients with type 1 diabetes. Regular self monitoring in patients with type 1 and type 2 diabetes is uncommon.
Age Factors↗
Property damage and public disorder: their relationship with sales of alcohol in New South Wales, Australia.
It has been suspected for some time that alcohol is involved in the origin of offensive behaviour and property damage incidents. Using regression analyses and a cross-sectional design, this study investigates these relationships for both Sydney and country New South Wales (NSW), whilst controlling for key social and demographic variables. The study found that both offence types occurred more frequently in areas with greater sales of alcohol. The effect of alcohol sales was considerably larger in Sydney than it was in country NSW. There was an interaction between aboriginal population size and alcohol sales for country NSW offensive behaviour data. Overall, these findings are consistent with alcohol consumption playing a causal role in these offences, however, the possibility remains that alcohol sales may be acting as an indicator of criminal opportunity.
Age Factors↗
Chronic right-lower-quadrant abdominal pain: is there a role for elective appendectomy?
BACKGROUND/PURPOSE: Chronic right-lower-quadrant abdominal pain is a frequent problem in the pediatric population. The purpose of this report is to detail the outcome of management of these patients with appendectomy. METHODS: Appendiceal colic was judged to be present if the history showed cramping abdominal pain in association with McBurney's point tenderness. This is a retrospective review of 50 consecutive pediatric patients experiencing pain for greater than 1 year. All patients were evaluated at a single institution by one surgeon and underwent elective appendectomies from April 1985 through April 1997. RESULTS: Seventy-five percent of the patients were girls. One hundred forty-nine imaging and endoscopic studies were performed with 135 negative findings. Twenty-three patients had a minimum of one previous emergency room visit or hospitalization for the same abdominal complaints. The pathological findings were distinctly different from those of incidental appendectomies. Three patients had undergone previous diagnostic explorations for abdominal pain, the appendix was not removed, and a subsequent appendectomy relieved the discomfort. Forty-nine of the 50 patients were pain free at 1 year. CONCLUSIONS: Appendiceal colic is a clinical diagnosis. It is anticipated that patients with cramping abdominal pain associated with McBurney's point tenderness could undergo less preoperative workup and expedited resolution of the problem in the future.
Abdominal Pain↗
The relationship between alcohol sales and assault in New South Wales, Australia.
AIMS: This paper explores the relationship between alcohol sales and assault in New South Wales (NSW), Australia. DESIGN: The design was a cross-sectional analysis of the relationship between alcohol sales and assault, taking into account spatial autocorrelation. SETTING: The analyses were carried out separately on data from metropolitan Sydney and country NSW. PARTICIPANTS: The unit of analysis was local government areas (178 in NSW). MEASUREMENTS: The dependent variable was assault rates. The independent variables were overall alcohol sales and sales disaggregated by alcohol and outlet type and relevant demographic and socio-economic factors. FINDINGS: Multiple regression analyses revealed a significant relationship between overall alcohol sales in an area and its incidence of assault for both Sydney and country NSW. There were few effects of outlet or alcohol type for Sydney, but the effect of alcohol sales from hotels and off-licences accounted for most of the alcohol-assault relationship for country NSW. CONCLUSIONS: Although the current research cannot exclude an opportunity account of the role of alcohol in assault, the results are entirely consistent with alcohol consumption as a causal agent.
Alcohol Drinking↗
Confusing tastes and smells: how odours can influence the perception of sweet and sour tastes.
This study investigated the relationship between perception of an odour when smelled and the taste of a solution to which the odour is added as a flavorant. In Experiment 1 (E1) sweetness, sourness, liking and intensity ratings were obtained for 20 odours. Taste ratings were then obtained for sucrose solutions to which the odours had been added as flavorants. Certain odours were found to enhance tasted sweetness while others suppressed it. The degree to which an odour smelled sweet was the best predictor of the taste ratings. These findings were extended in Experiment 2 (E2), which included a second tastant, citric acid, and employed four odours from E1. The most sweet smelling odour, caramel, was found to suppress the sourness of citric acid and, as in E1, to enhance the sweetness of sucrose. Again, odours with low sweetness suppressed the sweetness of tasted sucrose. The study demonstrated that the effects of odours on taste perception are not limited to sweetness enhancement and apply to sour as well as sweet tastes. The overall pattern of results is consistent with an explanation of the taste properties of odours in terms of prior flavour-taste associations.
Adult↗
Expression of the 'dead box' RNA helicase p68 is developmentally and growth regulated and correlates with organ differentiation/maturation in the fetus.
The human DEAD box protein p68 is an established RNA-dependent ATPase and RNA helicase, p68 has been highly conserved in evolution and appears to be essential for normal growth, suggesting that this protein plays an important role in the cell. Although the biochemical activities of p68 are fairly well characterized, little is known about its biological function. This report shows that p68 is detectable in quiescent cell lines, but its expression is induced by serum, suggesting that this protein may play a role in cell growth. It is also shown that both p68 mRNA and protein are differentially expressed in adult tissues; in this case, however, the levels do not always correlate with proliferation status, suggesting that the regulation of expression in the animal may be different from that in cell lines. Finally, it is shown that p68 expression is developmentally regulated and appears to correlate with organ differentiation/maturation. These findings suggest that p68 expression may not simply reflect proliferation/differentiation status and that it appears to be regulated in a more complex way.
Animals↗
The management of acute headache in adults in an acute admissions unit.
There have been no previously published studies about acute admissions with headaches to a medical admissions ward. In our retrospective case-note study of all patients admitted with headaches to the acute medical admission ward of Ninewells Hospital, Dundee over a six-month period, there were 114 admissions with headache (2.4% of all admissions). CT scans were done in 68 (59.6%) and were abnormal in 21 patients. Twenty four patients (21.1%) had serious underlying causes for headaches. Predictors for CT abnormalities are discussed. Eighteen patients had lumbar punctures and six had abnormal results. Most patients were discharged after one day, nine were transferred to the neurosurgical unit and there were two deaths. Deficiencies in record keeping were identified as was a lack of precision in diagnosis. Changes in practice are needed to improve patient care and perhaps national guidelines are required.
Acute Disease↗
Alcoholic ketoacidosis at autopsy.
Total ketone bodies (acetone, acetoacetate, and beta-hydroxybutyrate) were measured in 105 medicolegal autopsies (71 non-alcoholics, 22 chronic alcoholics, and 12 diabetics) using a coupled enzymatic head-space gas chromatographic method. Samples included vitreous humour, pericardial fluid, and blood from the femoral vein, inferior vena cava (IVC), superior vena cava (SVC), and aorta. Vitreous ketone levels showed good correlation with blood and pericardial fluid levels, suggesting that vitreous could be used as an alternative autopsy specimen for this analysis. This opens up the possibility of using simpler clinical laboratory methodologies which cannot be applied to autopsy blood due to hemolysis. In 71 non-alcoholics (age 18 to 96, median 67) total ketones (mM/L) were: vitreous 0.19 to 3.35, median 0.49; pericardial fluid 0.02 to 1.54, median 0.35; femoral blood 0.23 to 8.08, median 1.00; aortic blood 0.25 to 9.96, median 0.90; IVC blood 0.30 to 6.49, median 1.27; SVC blood 0.32 to 6.00, median 1.07. Eleven outliers (> 2.5 mM/L in femoral blood) mostly had prolonged illness prior to death. The 22 alcoholics (age 36 to 83, median 62) included four extreme outliers with femoral blood total ketone levels of 129.9 (also diabetic), 39.4 (no anatomical cause of death), 38.5 (suicidal hanging), and 18.6 (hypothermia), suggesting that while alcoholic ketoacidosis may be a previously overlooked potential cause of death, interpretation must be guarded and made within the total case context. The other 18 alcoholics had ketone levels not statistically different from non-alcoholics, suggesting that ketoacidosis is a significant factor in at most a small minority of alcoholic deaths. Three of 12 diabetics had extreme elevations of femoral blood ketone bodies: 87.5, 20.4, and 17.4 mM/L. Measurement of ketone bodies in vitreous humour or pericardial fluid using clinical laboratory methodologies is recommended in unexplained deaths in chronic alcoholics as well as diabetics.
3-Hydroxybutyric Acid↗
Judgments of chemosensory mixtures in memory.
Memory-based ratings of chemosensory mixtures produce response patterns similar to those observed perceptually. This finding is extended in two experiments. In the first, subjects mad judgments of sweetness, sourness and intensity in memory or with perceptually present combinations of sucrose and citric acid. Performance in both conditions was equivalent. Debriefing revealed some explicit knowledge about the way such mixtures interact. A second study investigated the relationship between such explicit knowledge and performance on the memory task. Here, subjects made the same ratings, but sampled, on separate days; (1) capsaicin alone, (2) a flavoured, sucrose, critic acid solution and imagined adding capsaicin, (3) the solution alone and (4) the solution actually with capsaicin. Performance was equivalent across the semi-mental and real mixture. Only sweetness was suppressed. Debriefing revealed that subjects thought all tastes and flavours were affected by capsaicin. Apart from extending previous findings, these studies suggest a role for both explicit and implicit memory processes in mental mixture judgments.
Humans↗
Disorientation in hypertext: the effects of three text structures on navigation performance.
A study is described which examines the effects of two hypertext topologies (hierarchy and non-linear) on navigation performance compared to a linear version of the same document. Subjects used the document to answer 10 questions. After a distraction period, subjects returned to the document to locate five specified nodes. Speed and accuracy measures were taken, and the subjects' own evaluation of their performance was assessed using a questionnaire. The results showed that subjects performed better with the linear text than with the non-linear text, while performance on the hierarchical document fell between these two extremes. Analysis of the questionnaire data confirmed these differences. The results are discussed in terms of their implications for computer-assisted learning systems.
Journal Article↗
Desensitization to oral zingerone irritation: effects of stimulus parameters.
In humans, repeated oral stimulation with the irritant capsaicin produces sensitization or desensitization, depending on the temporal relationship and, to a lesser extent, the intensity of the stimuli. We have previously shown that zingerone, an irritant present in ginger, shows only desensitization across repeated samples, as well as following a hiatus in stimulation. Because the time-course of zingerone irritation differs from that of capsaicin, it is likely that optimal temporal and other stimulation parameters may also be different. In Experiment 1, we examined the effects of stimulus intensity (0.5%, 1.0%, 2.0% zingerone) and the number of successive stimuli in a series on psychophysical responses to zingerone irritation within the series and following a 5-min hiatus. Experiment 2 examined the effect of the duration of this hiatus on desensitization and recovery. Desensitization was apparent across the initial series of stimuli in both experiments and, irrespective of zingerone concentration, in Experiment 1. Desensitization also occurred following the 5-min hiatus, evident primarily at the higher concentrations. Preceding the hiatus with 5 or 10 stimuli produced the greatest posthiatus desensitization, but a decrease in rated intensity was also evident following a single stimulus. Experiment 2 showed that the optimal hiatus for demonstrating desensitization was 5 min and that, by 15 min, recovery had begun. In both experiments, individual differences in response were marked, with some subjects showing sensitization and others little change in response across repeated zingerone stimuli. The origin of these differences is unclear but were shown to be relatively stable across multiple sessions.
Adult↗
Psychophysical responses to single and multiple presentations of the oral irritant zingerone: relationship to frequency of chili consumption.
There are few data on the psychophysical properties of zingerone, one of the pungent components in ginger, particularly in contrast to capsaicin. The time-intensity characteristics of zingerone irritation were examined using high-frequency, intermediate-frequency, and low-frequency users of chili, who rated the intensity of whole-mouth rinses of 1% zingerone at 6-s intervals for 3 min. Maximum intensity was reached within the first 20 s, while the zingerone was in the mouth. At this stage, there were no differences between groups. Following expectoration at 30 s, frequent users showed a more rapid decline in rated intensity than did intermediate users, who showed a more rapid decline than infrequent users. Capsaicin sensitization and desensitization are dependent upon the interstimulus intervals (ISIs) used. A second experiment, also using groups of high-, intermediate-, and low-frequency chili users, examined whether sensitization to zingerone could be demonstrated using ISIs based on the point of maximum intensity observed in the first study. In contrast to sensitization effects found with capsaicin, slight desensitization was observed over 10 successive zingerone stimuli. Following a 5-min hiatus in stimulation, further desensitization was observed over 10 results point to the ability of zingerone to self-desensitize, although the effect is of a smaller magnitude than that of capsaicin. None of these effects varied as a function of chili use. Analysis of the qualities that constituted zingerone irritation found that the sensations produced are predominantly burning and warmth, making it qualitatively similar to capsaicin.
Adult↗
Induction of gastroduodenal prolapse by antral heterotopic pancreas.
Ectopic pancreas is the most common congenital anomaly in the gastric antrum. In some patients, there is a distinct tendency for this lesion to produce intermittent crampy abdominal pain by provoking gastroduodenal prolapse. This condition should be considered after a more distal prolapse from intussusception is excluded. An upper gastrointestinal series performed during an episode of symptoms may be diagnostic of this entity.
Choristoma↗