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E P Köster

Publications and source records attributed to E P Köster.

18 recordsLinked to original sources
PubMed2006

Perceived stimulus complexity and food preference development.

The importance of perceived complexity, a "collative property" as defined by [Berlyne, D. E. (1967). Arousal and reinforcement. In Nebraska symposium on motivation (pp. 1-110). University of Nebraska Press], to the dynamic development of preference was investigated. Eighty-six female and 82 male subjects rated their liking for and various collative properties of seven very similar orange drinks that differed only in perceived complexity as a result of adding small quantities of other flavours. This was done before and after giving each subject extended experience of one of the drinks, each being used equally often for this purpose. As predicted by the theory of [Dember, W. N., & Earl, R. W. (1957). Analysis of exploratory, manipulatory and curiosity behavior. Psychological Review, 64 (2), 91-96] exposure to a stimulus with a slightly higher complexity than an individual subject's optimally preferred level of perceived complexity, caused an upwards shift in that level, whereas exposure to a less complex stimulus had no such effect. Changes in the appreciation of the drinks predicted by the theory were also observed.

Adolescent↗
PubMed2005

Do tastants have a smell?

The stimuli used in taste research are usually considered to be odourless. This was tested in two experiments with aqueous solutions of two representative compounds for each of the five taste qualities including umami. In the first experiment elderly and young subjects rated the intensity and pleasantness of three concentrations of the stimuli, while wearing or not wearing a noseclip. Saliva production was also measured. Blocking olfaction only influenced salivation for umami. It reduced taste intensity ratings, but as in an earlier experiment with the same compounds in food products, this effect was stronger in the young, who also liked the stimuli better wearing the noseclip. In the second experiment, another group of young people tried to detect the odours of the tastants dissolved in demineralized, double-distilled or Evian water. A considerable number of subjects could regularly detect seven of the ten tastants by olfaction and the extent to which they did correlated significantly with the reduction in taste intensity ratings for the different tastants found in the first experiment. We suggest that most tastants can be smelled and that this smell contributes to taste intensity ratings.

Adolescent↗
PubMed2005

Odor naming methodology: correct identification with multiple-choice versus repeatable identification in a free task.

Since there is rarely a social labeling consensus in the identification of odors, it would be better to assess whether participants identify an odor by the same name upon repeated presentation rather than by the name designated as 'correct' by the experimenter (veridical label) in identification tasks. To examine the relevance of this proposition, participants were asked to identify familiar odors both in a free and a multiple-choice task. The free task was replicated in order to determine the percentage of repeatable identification. Results showed that the difference between the percentage of correct identification in the multiple-choice task and the percentage of repeatable identification in the free task was small, and that participants often used a repeatable name which differed from the veridical label. Thus, it was suggested that allowing participants to give their own name to an odor when it is not present on a pre-developed list, and measuring whether participants repeat the same name in independent measurements, might improve the relevance of multiple-choice tasks.

Adolescent↗
PubMed2004

Incidental learning and memory for three basic tastes in food.

Forty three subjects were invited under the pretence that they would take part in an experiment on hunger feelings. They came without having eaten anything that morning and received a standard breakfast containing orange juice, cream cheese on crackers and yoghurt. These products were later (when subjects returned after scoring hunger feelings during the day) used as targets amidst a set of distractors varied by adding or subtracting different amounts of two basic tastes. Orange juice was varied in sweetness and bitterness, cream cheese in sourness and bitterness and yoghurt in sweetness and sourness. The changes were made comparable by using just noticeable differences, determined in preliminary experiments with other subjects, as units of change. Two measurements of memory were compared, an absolute (indicating which were the targets) and a relative one (indicating whether the targets and distractors were more, less or equally pleasant, sweet, sour, bitter or salty as the item eaten at breakfast). Both methods showed incidental learning, but relative memory was superior. Memory differed between tastes and was partly product dependent. These experiments suggest that taste memory is tuned to detect novel and potentially dangerous stimuli rather than to remember features of earlier experienced stimuli with great precision.

Adult↗
PubMed2002

Texture and flavour memory in foods: an incidental learning experiment.

Memory plays a major role in the formation of food expectations. How accessible and how accurate is incidentally acquired and stored product information? In the present experiment the memory for variations in texture (and flavour) was tested with a new and ecologically valid method. Subjects (N=69: 35 women, 34 men, age 19-59 yrs) came to the institute before having had breakfast and received a breakfast of several items (including breakfast drinks, biscuits and pâté). Subsequently, during the day, they answered questions about their hunger feelings every hour and returned for a taste experiment at the end of the day. When unexpectedly confronted with a series of multiple samples of four texture variations of each of the breakfast items mentioned above, they had to indicate which of these variations they had eaten at breakfast. Signal detection measures showed that most subjects recognised the eaten versions well for all three of the food items. Women remembered better than men. Both men and women used an equally conservative criterion.

Adult↗
PubMed2002

Selection of odorants for memory tests on the basis of familiarity, perceived complexity, pleasantness, similarity and identification.

In a procedure for the selection of two equivalent sets of familiar and two equivalent sets of unfamiliar odours for use in odour memory studies, 24 naïve subjects were first asked to rate the familiarity, perceived complexity and pleasantness of 54 a priori unfamiliar odours and 57 a priori familiar odours and to identify the latter. After selection of the 40 most familiar and the 40 least familiar odours, the subjects sorted each of these two sets into groups of similar odours. Their results were analysed by multidimensional scaling and cluster analysis and each set was divided into two recognition sets that had the same degree of similarity between target and distractor odours and that had similar values of familiarity, pleasantness, perceived complexity (familiar and unfamiliar sets) and identifiability (familiar sets). Finally, recognition tasks were performed in order to check the equivalence in memory performance of both the two familiar and the two unfamiliar recognition sets.

Adult↗
PubMed2001

Internal and external determinants of eating initiation in humans.

The influence of two internal variables (gender and nutritional state as measured by subjective hunger) and one external variable (either visual pre-exposure to a food stimulus or variation of the visual quality of the stimulus) on appetite for pizza in general or for a specific pizza, was studied in an experiment with 129 male and 225 female adult subjects, which were distributed in almost equal ratios over four sessions per day. They rated their hunger, their appetite for pizza (before and after visual presentation of the product) and their desire to eat a slice of any of four pizza varieties varying on visual characteristics. It was shown that appetite for the item pizza increased with hunger and with pre-exposure to the food, but that these two factors did not interact. Appetite for a specific pizza was influenced by its visual quality and by hunger, both factors acting independently. Compared to hunger, gender, the second internal factor, exerted a lesser influence. Furthermore, the reported appetite for a certain food item proved to be a good predictor of actual eating behaviour.

Adult↗
PubMed2001

Implicit learning and implicit memory for odors: the influence of odor identification and retention time.

One hundred and fifty-two subjects, divided into eight groups, were exposed to a room with a low concentration of either orange or lavender and to an odorless room. In a careful double-blind procedure, neither the subjects nor the experimenters were made aware of the presence of the odors in the experimental conditions. Later they were asked to indicate how well each of 12 odor stimuli, including the experimental and control odors, befitted each of 12 visual contexts, including the exposure rooms. At the end of this session they rated the pleasantness and the familiarity of the odors, and identified them by name. Finally they were debriefed and asked specifically whether they had perceived the experimental odors anywhere in the building. The results of four subjects who answered positively to the latter question were omitted. The results confirm the earlier finding that non-identifiers implicitly link odor and exposure room, whereas identifiers do not show such a link. It is suggested that episodic information is an essential constituent of olfactory memory and that its function is comparable to that of form and structure in visual and auditory memory systems.

Adult↗
PubMed1999

Odors: implicit memory and performance effects.

In order to assess the influence of odors on human performance and implicit memory for odors, 108 subjects completed a variety of tests in weakly scented (jasmine, lavender or odorless) rooms without having been made aware of the odor. After a 30 min interval the subjects were shown slides of different surroundings, including the room they had been in, and were requested to rate how well a set of 12 odors, including a blank, would fit to these surroundings. Half of these contexts contained visual cues related to two of the presented odors (leather and coffee). After the rating of fit the subjects had to rate the odors for pleasantness, were asked to identify the odors with their correct names and to tell where and when they had last smelled these odors. One subject remembered smelling the odor (jasmine) in the room and was discarded from the analysis of the results for the rating of fit. None of the others reported recollection of the experimental odors. The results showed that in general jasmine had a negative and lavender a positive effect on test performance. If an odor-related visual cue was present in the context, the related odor was always rated highest in fit to that context. Furthermore, the subjects working in rooms with an odor subsequently assigned this odor to the visual context of that room to a significantly higher degree than subjects working in rooms with different odors. Since none of the subjects reported that they had smelled the odor in the rooms where performance testing took place, it was concluded that the memory for these odors was implicit. Further analysis showed that such memory was only found in subjects who were unable to supply the right name for the odor. The possible consequences of this latter finding for understanding the relationship between sensory (episodic) and semantic odor memory are discussed.

Adult↗
PubMed1998

Implicit memory for odors: a possible method for observation.

In an experiment 143 subjects were instructed to assign odors to contexts which were displayed in a slide session. The slides depicted contexts from three areas of everyday life which partly contained visual cues related to a presented odor. After rating the fit of each odor to a context, the subjects rated the odors for pleasantness. Analysis showed a strong influence of the visual cue on the rating of fit for the contexts containing an odor-related visual element. In contexts without a visual cue, rating of fit showed an influence of implicitly learned memories of odor. The rating was not affected by the pleasantness of the odors. The 1995 work of Schab and Crowder is critically reviewed, and results are discussed within the framework of new, more ecologically oriented research on memory for odor.

Adolescent↗
PubMed1989

Temporal integration and reaction times in human smell.

A model description of intensity perception in human taste and smell developed earlier has now been verified experimentally to determine parameter values for odorants. The final objective is to quantify and understand odour-odour interaction phenomena in e.g., masking, deo-perfumes and flavour enhancement. Five types of olfactometer experiments were carried out, viz. determination of thresholds, determination of reaction times, scaling of perceived intensity after 5 sec stimulation, scaling of perceived intensity of a fixed concentration at variable duration, and measurement of intensity/time relationships. Four subjects were used and the odorants cineole, geraniol and hexane.

Acyclic Monoterpenes↗
PubMed1985

Interindividual differences in acuity for odor and aroma.

To determine the olfactory acuity of 27 subjects a sensory test was presented which was divided into 4 subtests, 2 for nasal and 2 for oral stimulation. Each subtest contained 28 (4 substances X 7 concentrations) olfactory detection tasks (items). The substances used were lemon and rum aroma as well as ethyl butyrate and amyl acetate, the solvents tap water and sugared tap water. Analysis showed that the test provided a clear differentiation between subjects of low, medium, and high olfactory acuity. The intercorrelations among the test substances and the split-half reliabilities of the subtests proved relatively high, whereas only moderate to low intercorrelations among the subtests were found. This was considered an effect of intraindividual variations of olfactory sensitivity. Finally, some conclusions for the construction of acuity tests for odor and aroma are presented.

Adolescent↗
PubMed1981

Sensory evaluation of drinking water by consumer panels.

The human senses play an important role in assessing the quality of food and of the environment. Particularly the chemical senses of taste and smell determine the pleasantness of foods and drinks and may provide a warning mechanism for the presence of more or less toxic contaminants. Even after the recent rapid development of powerful analytical techniques the human nose can easily detect trace amounts of chemicals at levels many times lower than the analytical detection limits. Although taste and odour assessment of drinking water has been practiced in many waterworks laboratories by small panels, relatively unreliable results were obtained and such sensory data played up till now only a minor role in the management of the water treatment plant. More sophisticated and reliable methods for sensory water quality evaluation are discussed. Special attention is given to the characteristics of the human senses of taste and smell, to which the methodology of sensory assessment should be better adapted. High numbers of observations on a sample are generally needed, for which purpose the use of large panels has to be realized. In this respect the help of large consumer panels is an alternative for the presently often used small laboratory groups. As an example the preliminary results of a large ongoing experiment of sensory water quality assessment by 2 consumer panels of 100 persons each in the Rotterdam area are discussed. Drinking water quality is judged at the consumer homes every week. The experiment started September 1979 and will be continued for one year.

Humans↗