Oral size perception and texture preferences for particle-containing foods in children aged 5-12.

Foods containing bits and pieces are often less liked by children; however, there is a limited understanding of how perceptions and preferences for foods with particles change during childhood. This study aimed to investigate preferences and perceptions of particle-containing foods in children aged 5-12 years. Children (n = 485) completed a forced-choice questionnaire on drawings of six pairs of foods, each available with or without particles. Additionally, children tasted yogurts added with muesli differing in particle size (median diameter: 3.9 or 7.5 mm) and evaluated their perception of particle size in mouth and their liking. The questionnaire results showed that children had a clear preference for foods without particles. The average probability of choosing the 'with-particle' foods was 28%, significantly below the midpoint of 50% (p < .0001). Preferences for particle-containing foods were lowest at age six and increased significantly with age (p = .0007). In the taste test, muesli particle size affected oral size perception (p < .0001) but not liking (p = .60). Older children were better able to differentiate particle size than younger children. However, there was no relationship between individual preferences for particle-containing foods and oral size perception of muesli particles. The observation that children's texture preferences changed with age highlights the role of increased experience in shaping preferences for foods with particles.

Oral hapsis guides accurate hand preshaping for grasping food targets in the mouth.

Preshaping the digits and orienting the hand when reaching to grasp a distal target is proposed to be optimal when guided by vision. A reach-to-grasp movement to an object in one's own mouth is a natural and commonly used movement, but there has been no previous description of how it is performed. The movement requires accuracy but likely depends upon haptic rather than visual guidance, leading to the question of whether the kinematics of this movement are similar to those with vision or whether the movement depends upon an alternate strategy. The present study used frame-by-frame video analysis and linear kinematics to analyze hand movements as participants reached for ethologically relevant food targets placed either at a distal location or in the mouth. When reaching for small and medium-sized food items (blueberries and donut balls) that had maximal lip-to-target contact, hand preshaping was equivalent to that used for visually guided reaching. When reaching for a large food item (orange slice) that extended beyond the edges of the mouth, hand preshaping was suboptimal compared to vision. Nevertheless, hapsis from the reaching hand was used to reshape and reorient the hand after first contact with the large target. The equally precise guidance of hand preshaping under oral hapsis is discussed in relation to the idea that hand preshaping, and its requisite neural circuitry, may have originated under somatosensory control, with secondary access by vision.

Separating the effects of prey size and speed on the kinematics of prey capture in the omnivorous lizard Gerrhosaurus major.

Feeding behavior is known to be modulated as prey properties change. During prey capture, external prey properties, including size and mobility, are likely some of the most important components in predator-prey interactions. Whereas prey size has been demonstrated to elicit modulation of jaw movements during capture, how prey speed affects the approach and capture of prey remains unknown. We quantified the kinematics associated with movements of both the feeding and locomotor systems during prey capture in a lizard, Gerrhosaurus major, while facing prey differing in size and mobility (newborn mice, grasshoppers, and mealworms). Our data show that the feeding and locomotor systems were recruited differently in response to changes in the size or speed of the prey. The timing of jaw movements and of the positioning of the head are affected by changes in prey size-and speed, to a lesser extent. Changes in prey speed resulted in concomitant changes in the speed of strike and an early and greater elevation of the neck. External prey properties, and prey mobility in particular, are relevant in predator-prey interactions and elicit specific responses in different functional systems.

Sexual dimorphism in facial shapes and their discrimination in Japanese monkeys (Macaca fuscata).

The authors examined the ability of Japanese monkeys (Macaca fuscata) to discriminate between sexes based on facial features. The shape and position of facial features (facial morphology) were measured to quantify the differences between sexes. The distance between the chin and nose was longer in males than females, and the outline of the face around the upper jaw and upper face differed between sexes. Using operant conditioning, 2 monkeys succeeded in discriminating sex based on facial pictures. Furthermore, they successfully generalized the discrimination to novel pictures of faces. Tests with morphed pictures of faces revealed that the monkeys used facial morphology to discriminate between males and females. Our results suggest that Japanese monkeys have sexual dimorphism in facial shape and they can use the morphological differences to discriminate conspecific sex.

Modulating the masked congruence priming effect with the hands and the mouth.

The authors report a series of experiments in which they use the masked congruence priming paradigm to investigate the processing of masked primes in the manual and verbal response modalities. In the manual response modality, they found that masked incongruent primes produced interference relative to both congruent and neutral primes. This finding, which replicates the standard finding in the masked congruence priming literature, is presumed to reflect the conflict that arises between two incompatible responses and, thus, to index the extent of processing of the masked prime. Somewhat surprisingly, when participants were asked to respond verbally in the same task, masked incongruent primes no longer produced interference, but masked congruent primes produced facilitation. These findings are surprising because they suggest that the processing of nonconsciously perceived primes extends to the response level in the manual, but not verbal, response modality. The authors propose that the modulation of the masked congruence priming effect by response modality is due to verbal, but not manual, responses being mediated by the lexical-phonological production system.

The effects of food viscosity on bite size, bite effort and food intake.

Two studies investigated the effect of a food's viscosity on bite size, bite effort and food intake using a standardized protocol in which subjects sipped through a straw every 20 s for a period of 15 min from one of two products, a chocolate-flavored dairy drink and a chocolate-flavored dairy semi-solid, matched for energy density. In the first study, subjects consumed 47% more from the liquid than from the semi-solid to reach the same degree of satiation, with larger bite sizes for the liquid throughout the 15 minute period (8.7+/-0.45 g) compared to the semi-solid (5.8+/-0.3 g, p<0.01). In the second study bite effort was eliminated by using a peristaltic pump to present the products every 20 s. Oral processing time before swallowing was set at 5 s (both products) or 8 s (semi-solid). With the elimination of bite effort and a standardized oral processing time, subjects consumed as much from the semi-solid as from the liquid to reach the same degree of satiation. Bite size for liquids started relatively small and grew gradually over successive bites, whereas the bite size for the semi-solid food started relatively large and became gradually smaller. The latter effect was even more pronounced when the oral processing time was increased from 5 to 8 s. In conclusion, semi-solids resulted in smaller bite sizes and lower intake than liquids, but these differences disappeared when differences in bite effort were eliminated.

Cross-modal influence on oral size perception.

OBJECTIVE: Evidence suggests people experience an oral size illusion and commonly perceive oral size inaccurately; however, the nature of the illusion remains unclear. The objectives of the present study were to confirm the presence of an oral size illusion, determine the magnitude (amount) and direction (underestimation or overestimation) of the illusion, and determine whether immediately prior cross-modal perceptual experiences affected the magnitude and direction. DESIGN: Participants (N=27) orally assessed 9 sizes of stainless steel spheres (1/16 in to 1/2 in) categorized as small, medium, or big, and matched them with digital and visual reference sets. Each participant completed 20 matching tasks in 3 assessments. For control assessments, 6 oral spheres were matched with reference sets of same-sized spheres. For primer-control assessments, similar to control, 6 matching tasks were preceded by cross-modal experiences of the same-sized sphere. For experimental assessments, 8 matching tasks were preceded by a cross-modal experience of a differently sized sphere. RESULTS: For control assessments, small and medium spheres were consistently underestimated, and big spheres were consistently overestimated. For experimental assessments, magnitude and direction of the oral size illusion varied according to the size of the sphere used in the cross-modal experience. CONCLUSION: Results seemed to confirm an oral size illusion, but direction of the illusion depended on the size of the object. Immediately prior cross-modal experiences influenced magnitude and direction of the illusion, suggesting that aspects of oral perceptual experience are dependent upon factors outside of oral perceptual anatomy and the properties of the oral stimulus.

Relating particles and texture perception.

Practically all foods contain particles. It has been suggested that the presence of particles in food may affect the perception of sensory attributes. In the present study we investigated the effect of size and type (hardness and shape) of particles added to a CMC based vanilla custard dessert. The two types of particles included in the study were silica dioxide and polystyrene spheres, varying in size from 2 to 230 microm. Eighteen trained adults participated in the study. They rated the sensation of 17 sensory flavour and texture attributes on a 100-point visual analogue scale (VAS). The results indicate that the addition of particles increased the sensation of roughness attributes and decreased the ratings of a number of presumably favorable texture attributes (smoothness, creamy, fatty and slippery) significantly. These effects increased with increasing particle size up to 80 microm. Roughness ratings deceased for larger particles sizes. Surprisingly, even particles of 2 microm had significant effects: they increased perceived rough lip-tooth feel, and decreased slippery lip-tooth feel and smoothness of the product. The affected attributes had previously been related to lubricative properties of foods. Particles added to semi-solid foods with relatively low levels of fat seem to counteract the lubricating effects of the fat resulting in increased oral friction. In a separate study on size perception the silica dioxide particles were used. By sampling the stimuli between the tongue and palate, subjects rated the size of the particles on a 100-point scale in comparison to anchor stimuli containing no particles and particles of 250 microm. The perceived particle size significantly increased for larger particles. Furthermore, perceived particle size was negatively correlated with roughness ratings. Thus, subjects who were sensitive and perceived the particles as being relatively large reported the same stimuli to have less rough after-feel. In conclusion, particles added to a product induce large effects on texture sensations, and texture sensation is related to individual size perception.

Action observation and speech production: study on children and adults.

The present study aimed to determine whether observation of upper limb actions selectively influences speech production. We compared the effects on children with those on adults, hypothesizing that action observation is used by children for speech learning. Children and adults observed an actor either grasping a cherry or an apple, or bringing the same fruits to his mouth. They pronounced the syllable/ba/ at the end of the action. In a control experiment, children and adults executed the two bringing-to-the-mouth actions, still pronouncing/ba/. As previously found ([Euro. J. Neurosci., 17 (2003) 179]; [Euro. J. Neurosci., 19 (2004) 192]), the observed kinematics of the action, which were different according to the fruit size, influenced lip shaping kinematics and voice formants. In addition, the effect was selective for the action since the observations of actions such as grasping and bringing-to-the-mouth affected formant 1 and formant 2 in the voice spectra, respectively. The effects on speech were greater in the children than in the adults. By contrast, the effects on lip shaping did not differ between the two groups. Effects similar to those found for action observation were found for action execution in spite of a different arm kinematics between children and adults. The results of the present study are discussed according to the hypothesis that action observation induces in the viewer action recognition and activation of the successive mouth act (probably grasping-with-the-mouth when observing grasping-with-the-hand and chewing when observing bringing-to-the-mouth). This subsequently seems to affect characteristics peculiar to the emitted vowel. This mechanism might have been used by humans to transfer a primitive arm gesture communication system from the arm to the mouth and may be further used by children for speech learning.

Inattention magnifies perceived length: the attentional receptive field hypothesis.

Five experiments demonstrated that a briefly presented vertical line is judged as longer when it is unattended relative to when it is attended. This effect was obtained in estimating the length of 1 of 5 possible lines (Experiment 1) and in matching the length of a test line to a criterion line (Experiments 3 and 4). The directional effect of attention was eliminated when participants estimated the length difference between 2 simultaneously presented lines (Experiment 2). An additional matching experiment (Experiment 5) demonstrated similar lengthening effects for unattended lines and for unattended distances separated by vertically displaced dots. It is proposed that the metric for unattended stimuli is composed of large attentional receptive fields and that the final output is mediated by rounding up processes, so that the unattended line is systematically perceived as longer than the attended one.

Artificial language comprehension and size transposition by a California sea lion (Zalophus californianus).

A variation of the conditional discrimination procedure defines relations between stimuli (for example, gestural signs and their referents), and it has been used to study language comprehension in California sea lions. The animals followed instructions given by a trainer's gestures designating properties of size, brightness, and location (adjectives), types of objects (nouns), and actions (verbs). The signs can be combined and recombined according to a conditional sequence or syntax. In this study, we sought to determine whether adjectives for size had an absolute meaning, that is, small and large, as well as a comparative meaning, that is, smaller and larger. A sea lion, Rocky, was given experience with signs designating standard small and large spheres in commands like LARGE BALL MOUTH. On transposition tests, the small ball was removed and the previously designated large ball was paired with an even larger one. The results showed that the adjectives had both an absolute and a relative meaning. Object choices and searching behavior revealed that the sea lion processed information about the relation of size as well as about the specific characteristics of the sizes of spheres that instantiated the relations.

The influence of density and material on oral perception of ball size with and without palatal coverage.

The size of a bolus determines how it will be manipulated in the mouth and swallowed. Ten healthy individuals assessed the size of ball bearings of five sizes (4-11 mm diameter) and four materials with different densities in order to investigate the effect of weight on oral size perception. To study the role of the tongue and palate, the experiment was performed with and without a custom-made plastic palate. The results revealed that size itself determines size perception, and that material and weight are negligible factors. An illusional effect in the direction of under-estimation was found for the ball bearings, especially for the small sizes up to 8 mm diameter. While wearing a plastic palate a significant improvement (P<0.05) occurred; the participants performed better and there was less under-estimation. An explanation for this could be that only a minor part of the total area of the ball bearing touches the palate and is hence detected, while the tongue alone is more compliant and thereby able to sense the ball's whole size.

Autoshaping the pigeon's gape response: acquisition and topography as a function of reinforcer type and magnitude.

The pigeon's key-pecking response is experimentally dissociable into transport (head movement) and gape (jaw movement) components. During conditioning of the key-pecking response, both components come under the control of the conditioned stimulus. To study the acquisition of gape conditioned responses and to clarify the contribution of unconditioned stimulus (reinforcer) variables to the form of the response, gape and key-contact responses were recorded during an autoshaping procedure and reinforcer properties were systematically varied. One group of 8 pigeons was food deprived and subgroups of 2 birds each were exposed to four different pellet sizes as reinforcers, each reinforcer signaled by a keylight conditioned stimulus. A second group was water deprived and received water reinforcers paired with the conditioned stimulus. Water- or food-deprived control groups received appropriate water or food reinforcers that were randomly delivered with respect to the keylight stimulus. Acquisition of the conditioned gape response frequently preceded key-contact responses, and gape conditioned responses were generally elicited at higher rates than were key contacts. The form of the conditioned gape was similar to, but not identical with, the form of the unconditioned gape. The gape component is a critical topographical feature of the conditioned key peck, a sensitive measure of conditioning during autoshaping, and an important source of the observed similarities in the form of conditioned and consummatory responses.

[Anterior denture teeth selected for complete dentures].

The purpose of this study was to investigate the influence of sex and age on the selection of color, size, and form of anterior teeth for complete dentures. A sample representing one hundred eighty-five edentulous patients whose complete dentures were made with. Real Crown teeth (Shofu Inc.) was obtained. The results were as follows: 1) Lighter teeth were selected for females than males, but age had no relation to the selected color of the teeth. 2) Larger teeth were selected for males than females, but age had no relation to the selected size of the teeth. 3) The combination and tapering forms were selected frequently, the combination form was used more frequently for females than males and the tapering form was used more frequently for males than females.

[Sensory receptors on oral thickness sensation].

The purpose of this study was to evaluate the role of the receptors connected with oral thickness perception. Twenty dentate volunteers participated in this study. The right second premolars were selected as test teeth. The thickness perception test was performed using aluminum foil. The experimental conditions were: 1) two types of occlusal contact positions; intercuspal position and teeth contact position of a single pair, 2) two types of closing velocities: "slow closure" and "fast closure" which were synchronized with 50 and 150/min metronome, and 3) application of local anesthesia to test teeth. The number of incorrect assessments for all trials and the proportion of correct assessments for actual trials were used for analysis. There were significant increases of incorrect assessments below 200 microns in "slow closure" at teeth contact position of a single pair. The minimum thickness of 80% of correct assessment was 100 microns both with and without anesthesia in "fast closure" at teeth contact position of a single pair. There were significantly fewer incorrect assessments in "fast closure" than in "slow closure" with anesthesia at teeth contact position of a single pair. These findings suggest that the closing velocity may influence oral thickness perception.

The eye-size illusion: psychophysical characteristics, generality, and relation to holistic face processing.

Rakover [(2011). In Y. H. Zhang (Ed.), Advances in face image analysis: Techniques and technologies (pp. 316-333). Hershey, PA: IGI Global] observed a novel eye-size illusion: when increasing the size of a face but keeping the size of its eyes unchanged, the eyes are perceived to be smaller than in the original face. Here, we systematically manipulated the face size and found that the magnitude of this illusion linearly changed as a function of the face frame size (experiment 1). Additionally, the same magnitude of an illusion was observed for the perception of the size of the mouth when we changed the face frame but kept the mouth size constant (experiment 2). Further, when the faces and eyes were presented upside down, the magnitude of the illusion was significantly reduced in both Chinese participants (experiment 3) and Caucasian participants (experiment 4). The results suggest that the perception of eye or mouth size occurs in the relational context of the whole face; and when the face is inverted, thereby disrupting holistic processing, the magnitude of the illusion is reduced. We therefore suggest that holistic processing is involved in producing the illusion.

[Implementation of a scale on stone baskets]. / Implementierung einer Skala auf Steinfangkörben.

BACKGROUND: Complications after endoscopic retrieval of kidney and ureter stones are obviously related to the size of the stones as well as the experience of the surgeon and other factors. During the procedure it is sometimes difficult for surgeons to estimate stone size and therefore give prognostic advises. The visual perception of the stone size depends on the shape, colour, distance to the renoscope and dilatation of the ureter. This is the so-called binding problem, because shape, color and direction of motion are processed separately by different population of optical neurons. In order to establish a better prognostic ratio, especially for less experienced surgeons we established an intraoperative semi-quantitative measurement of the stone size supported by a stone basket. MATERIALS AND METHODS: We modified the tipped nitinol stone baskets from the company Urotech with diameters of 2.5, 3.0 and 4 Ch. The handle of this basket has a spring mechanism, which automatically closes the basket and provides a predefined fixation force of the stones within the basket. On the handle we established a non-linear scale in mm by grabbing standardized balls or standardized screws. RESULTS: The scales are nonlinear because of the nonlinear relation between the diameter of the stone and the distance of the slider. Also the scales differ in between the basket size, because of the different strain conditions due to the different wire sizes and materials or the spring and basket. CONCLUSIONS: This scale could be an important orientation for a surgeon during endourological procedures to estimate stone sizes. It could be used also for the documentation of the size of fragments after an endourologic lithotripsy and could help in the decision for or against an extraction. Finally it could be very interesting for other disciplines like gastroenterology. The scale should be validated in further clinical trials.

Dentists make larger holes in teeth than they need to if the teeth present a visual illusion of size.

BACKGROUND: Health care depends, in part, on the ability of a practitioner to see signs of disease and to see how to treat it. Visual illusions, therefore, could affect health care. Yet there is very little prospective evidence that illusions can influence treatment. We sought such evidence. METHODS AND RESULTS: We simulated treatment using dentistry as a model system. We supplied eight, practicing, specialist dentists, endodontists, with at least 21 isolated teeth each, randomly sampled from a much larger sample of teeth they were likely to encounter. Teeth contained holes and we asked the endodontists to cut cavities in preparation for filling. Each tooth presented a more or less potent version of a visual illusion of size, the Delboeuf illusion, that made the holes appear smaller than they were. Endodontists and the persons measuring the cavities were blind to the parameters of the illusion. We found that the size of cavity endodontists made was linearly related to the potency of the Delboeuf illusion (p<.01) with an effect size (Cohen's d) of 1.41. When the illusion made the holes appear smaller, the endodontists made cavities larger than needed. CONCLUSIONS: The visual context in which treatment takes place can influence the treatment. Undesirable effects of visual illusions could be counteracted by a health practitioner's being aware of them and by using measurement.