PSY 333 Exam 2 | Complete Solutions (Answered)

PSY 333 Exam 2 | Complete Solutions (Answered) How does maternal diet affects infants' taste preferences? Infants born to mothers who consumed garlic showed enhanced appetitive oral reactions and less distaste when re-exposed to garlic paste How does diet exposure in children influence taste preference? Children restricted from sweets preferred higher sucrose concentrations, while those fed protein hydrolysate formulas preferred sour foods. What is the relationship between BMI and taste preferences? Individuals with BMIs 30 had higher liking scores for salt, fat, and sweet foods compared to those with BMI 25 How does obesity affect taste recognition thresholds? Obese individuals required higher concentrations of sucrose or salt to recognize tastants What are the physiological changes in taste due to dietary obesity? Obesity reduces CD36 expression in taste cells and downregulates umami and sweet taste receptors (TIR3) How does obesity affect brain responses to taste? Obese individuals show heightened activity in the right insular cortex when consuming bitter and sweet foods. What is Roux-en-Y gastric bypass (RYGB) and how does it impact taste? A weight-loss surgery that reduces stomach size; it decreases the liking of sucrose, but not its intensity What is the "vicious cycle" hypothesis of taste hypofunctionality? Reduced taste signaling due to gene expression changes dads to increased food intake, reinforcing unhealthy eating behaviors. What are supertasters, and how are they different? Supertasters have more taste papillae and taste cells, making them more sensitive to certain tastes, especially bitter ones. What genetic factor is associated with supertasting? The TAS2R38 gene on chromosome 7 is linked to sensitivity to bitter tastes like PTC. What is taste? The sensory quality of food detected in the mouth, influencing acceptance or rejection. What are the two main taste reactions? Liking (pleasure) and disliking (aversion) How can scientists study taste perception in humans? Through psychophysical tests that measure taste detection and recognition thresholds. How do taste and smell interact? They work together to determine whether a food should be consumed. Where does taste detection begin in mammals? In the tongue's epithelial-derived taste cells located in taste buds. How often do human taste cells regenerate? Approximately every 10 days. What receptors mediate sweet taste? T1R2 and T1R3, which are G-protein coupled receptors (GPCRs) What receptors mediate umami taste? T1R1 and T1R3 What receptors mediate bitter taste? T2R GPCRs, with different receptors recognizing various bitter compounds. How is salt taste detected? Through the epithelial sodium channel (ENaC) What is the main receptor for sour taste? PKD2L1 ion channel What evidence suggest fat might be a detectable taste? The CD36 fatty acid transporter in lingual papillae contributes to fat detection How does taste information reach the brain? Through cranial nerves that transmit signals to the nucleus of the solitary tract. Where is taste processed in the brain? In the gustatory cortex. What are the two main theories of taste coding in the brain? The "labeled-line- theory (each taste has a designated pathway The "across-fiber" theory (taste is encoded through patterns of activation) When do presumptive taste buds first appear in human development? Around 7 weeks of gestation. When do taste papillae develop and when do they mature? Present by 12 weeks and biologically mature by the third trimester. How does exposure to amniotic fluid affect fetal taste preferences? Flavors from the mother's diet transfer through amniotic fluid, influencing taste preferences. What was the key finding from the study on garlic exposure in utero? Infants whose mothers consumed garlic showed fewer aversive reactions to garlic flavors after birth. What is neophobia, and why do young children exhibit it? Fear of trying new foods. An evolutionary defense mechanism against harmful substances. What happened to children who were highly restricted from eating sweets? They showed a stronger preference for sweets when later given the option. How did early exposure to sour formula affect children's taste preferences? Infants fed sour formula had a higher preferences for sour foods at ages 4-5, but this preference faded by age 7. How does a high-fat, high-sugar diet affect taste sensitivity? It may reduce taste sensitivity, requiring higher concentrations of sugar or fat to experience the same taste. What was the result of a 7-day low-sugar diet on taste perception? There was no significant change, suggesting long-term changes are needed to alter taste preferences. How does obesity affect taste perception? Higher BMI individuals tend to have higher taste detection thresholds (need stronger flavors to perceive taste). How do obese individuals' brains react to sweet foods differently? They show greater activation in taste-processing brain areas when consuming sweets. How does a high-fat diet affect taste receptors? It can lead to downregulation of taste receptors, making people less sensitive to fat and sweetness What is CD36, and how is it affected by diet? CD36 is a fat-detecting taste receptor, which is downregulated in high-fat groups What genetic difference makes cats unable to taste sweetness? Cats lack the T1R2 receptor, which is necessary for detecting sweetness What percentage of the population are super tasters, and what makes them unique? 25% are super tasters, with more taste papillae and higher sensitivity to certain bitter compounds like PROP. What is the gustatory system? The sensory system responsible for taste. What is downregulation, and how does it affect taste? Reduction in receptor activity due to frequent exposure to a certain taste (e.g., high sugar/fat diets) What is the difference between taste liking and taste perception? Liking refers to how pleasurable a taste is, while perception refers to how strong the taste is sensed. How do early taste experiences influence food preferences later in life? Exposure to certain flavors in infancy can increase or decrease preference for those flavors later in life. What is olfaction? Olfaction relates to the sense of smell and reflects the chemical information individuals experiences when perceiving odors. Where are the receptor neurons for olfaction located? Within the olfactory epithelium in the nose What are the three types of cells found in the olfactory epithelium? Receptor neurons, supporting cells, and basal cells. How do olfactory receptor cells connect to the brain? An apical dendrite extends to the mucosal surface with cilia emerging from the dendritic knob, while an axon extends to the olfactory bulb through the cribriform plate How does olfaction influence dietary choices? The odor released by foods and drinks affect dietary choice, energy intake, and palatability Wha is the odor detection threshold? It is the lowest concentration at which an odor can be perceived. How are odors released from food? Through volatile organic compounds emitted into the air, decomposition by microbes, or chemicals produced by microbes. Why are there more flavors than tastes? Flavor is a combination of olfaction and taste leading to a greater variety. How do humans combine odor and taste perceptions? We attribute odors with qualities typically associated with basic tastes (e.g., the sweet taste of vanilla). How do different odors impact sweetness perception? Some odors enhance the sweetness of foods, while others reduce it How does body weight relate to olfactory ability? Obese individuals have higher olfactory thresholds, meaning they have reduced olfactory discrimination What is visceral fat a predictor of? Overall olfactory scores How does a high-fat diet affect olfaction? It reduces the connectivity of the olfactory system and olfactory discrimination What did an odor imagery mismatch reveal about weight gain? Participants who performed better at imagining odors showed greater weight gain over one year Where are the receptors for ghrelin (the hunger signal) expressed in the brain? In the brain's olfactory processing centers, such as the olfactory bulb How does Leptin receptor deficiency affect or olfactory sensitivity in rats? Obese rats with a Leptin receptor mutation showed heightened sensitivity to olfactory cues and increased nose-poking behavior What is chemosensation? The ability to combine gustatory (taste) and olfactory (smell) information to interact with the food environment and guide dietary choices How do taste and odor interact with the visual system? They influence food perception, determining which food are appetizing. What was the finding of the reaction time task related to BMI? Higher BMI was correlated with increased reaction times and greater insular cortex activity when assessing food images. What are the key factors influencing food preference? The sense of smell, taste, and visual cues How do diet and body weight affect olfaction? They influence sensitivity, thresholds, and perception What physiological changes underlie differences in olfactory capacity? Changes in both brain function and peripheral physiology What is a supertaster? A supertaster is someone with a heightened ability to taste certain flavors, particularly bitterness, due to a higher number of taste receptors Which receptor cells are involved in bitter taste perception? T2R receptors are responsible for detecting bitter compounds What genetic mutation is associated with supertasting? A mutation on a chromosome related to the T2R receptor gene increases sensitivity to bitter tastes How was taste sensitivity tested in the class experiment? Students applied PTC or phenylthiocarbamide to their tongues and rated its bitterness intensity How does genetic variation influence taste perception? Differences in taste receptor genes determine individual sensitivity to flavors, particularly bitterness What is chemosensation? Chemosensation is the ability to integrate gustatory (taste) and olfactory (smell) information to perceive flavors Which senses interact to shape food perception? Taste, smell, and visual cues all contribute to the perception of food How does olfaction influence food preference? Smell enhances flavor perception and can determine whether a food is appealing or unappealing Why do foods seem tasteless when we have a congested nose? Congestion blocks olfactory receptors, preventing volatile compounds from reaching them, which reduces flavor perception How does odor detection work in the olfactory system? Chemical compounds bind to olfactory receptors in the nose, sending signals to the brain to interpret different smells. Where are olfactory receptor neurons located? In the olfactory epithelium beneath the cribiform plate in the nose? Which brain structure first processes olfactory signals? The olfactory bulb Which brain regions are involved in integrating smell and taste? The piriform cortex, amygdala, insular cortex, and hypothalamus What role does the amygdala play in olfactory processing? It connects odors with emotions and memories What is the primary function of the piriform cortex? It processes olfactory information and helps with odor discrimination How do odors influence sweetness perception? Certain odors, like strawberry and caramel, enhance the perception of sweetness What is flavor-nutrient learning? The process by which our brain associated specific flavors with nutritional benefits, reinforcing food preferences How does obesity affect olfactory sensitivity? Obese individuals tend to have reduced olfactory discrimination and require higher odor concentrations to detect scents. What did research show about visceral fat and olfaction? Higher levels of visceral fat correlate with decreased olfactory sensitivity How does a high-fat diet affect the olfactory system? It reduces neural connectivity in the olfactory tract and weakens odor discrimination What is ghrelin, and how does it affect olfaction? Ghrelin is the hunger hormone, and it enhances odor detection, increasing food cravings Where are ghrelin receptors located in the olfactory system? In the olfactory bulb How does hunger influence odor perception? When hungry, people are more sensitive to food odors and may perceive them as more intense What did a study on odor imagery reveal about weight gain? People who were better at imagining food odors showed higher weight gain over a year What is the relationship between Leptin and olfactory sensitivity? Leptin-deficient rats exhibited heightened sensitivity to food odors, indicating Leptin plays a role in olfactory regulation Which senses interact to shape food perception? Taste, smell, and vision all contribute to food perception and preference How does visual stimuli influence food cravings? Seeing food images can activate the brain's gustatory and olfactory areas, increasing food cravings What brain region is associated with processing both taste and smell? The insular cortex Why do food advertisements use sound, visuals, and imagery? Multi sensory cues enhance cravings and reinforce brand association How does a sinus infection affect flavor perception? It blocks the olfactory receptors, making food taste bland due to the lack of aroma detection What is the primary function of ghrelin in the body? Ghrelin stimulates appetite and promotes food intake by acting on the hypothalamus Where in the stomach is ghrelin primarily produced? Ghrelin is decreed by endocrine cells in the gastric mucosa What happens to ghrelin levels after a meal? Ghrelin levels decrease significantly following food consumptions, signaling satiety What are the effects of intracerebroventricular (ICV) administration of ghrelin in rodents? It increases food intake and upregulates hypothalamic neuropeptide Y (NPY), a potent hunger signal How does ghrelin secretion differ between normal-weight and anorexic individuals? Individuals with anorexia nervosa have higher ghrelin levels, possibly as a compensatory mechanism How does prolonged fasting affect ghrelin secretion? Ghrelin levels increase significantly after 12 hours of fasting, promoting hunger What evidence suggests that ghrelin acts as a physiological meal initiator? Ghrelin levels rise sharply before meals and drop immediately after eating What hormone shows an opposite secretion pattern to ghrelin? Insulin— it increases after meals while ghrelin decreases How does gastric bypass surgery affect ghrelin levels? Patients who undergo total gastrectomy have drastically reduced ghrelin levels