Psychology: Sensation and Perception

Tasting sense helps people to evaluate what they are consuming. Taste buds help in the experience of taste. These are special structures that are embedded within papillae. Papillae are small protuberances found on the tongue. Taste buds are found at the back of mouth and on Palate. Each person has between five thousand taste buds and ten thousand. The taste buds have between fifty to one hundred sensory cells that are specialized (Melis & Barbarossa, 2017). When these cells are stimulated, signals information is transferred to the brain along cranial nerves. From taste regions in the brain, impulses are transmitted to the cerebral cortex. At this point, we become conscious of the taste experience.

Five basic sensations are provided by taste receptors. These are spicy, bitter, savory, sour and sweet. The taste buds are specialized to the reception of every sensation. The sweet sensation is experienced when sweetness signals sugar presence. The transduction of sweet taste involves binding of GGPCRs (Melis & Barbarossa, 2017). Their mechanism depends on molecule flavor. Bitter sensation helps in differentiating various compounds with a bitter response. The salt receptors are the simplest of receptors in the mouth. When sodium ions enter the taste cell through the ion channel, cell depolarization occurs and it is flooded with ions. This leads to a release of neurotransmitter. Sour sensation signals when substances have acidic compounds (Melis & Barbarossa, 2017). Finally, the umami sensation detects the presence of glutamates found in cheese, meat, and other foods that are heavy in proteins.

When we chew food, for instance, food chemicals are dissolved. The taste buds discover these chemicals. The flavors are then transformed into impulses which are directed to the brain where detection takes place. The detection process takes place very fast enabling human beings to identify the taste (Melis & Barbarossa, 2017). This process explains why people react almost immediately after chewing substances.

  1. How does our sense of smell work? Discuss the concept that our sense of smell is directly connected to the brain. After you have fully and completely answered this question from a biological perspective, include a relevant example which illustrates your answer.

The molecules found in the air we breathe lead to the perceived smell. Substances that don’t release molecules into the air don’t have a smell. Similarly, if an individual lacks receptors that recognize a certain molecule then the molecule doesn’t have a smell. Over 350 olfactory receptor subtypes enable human beings to sense over 1000 smells. Olfaction forms the smell sense through the chemoreception. Olfaction serves various purposes including detecting food, hazards, and pheromones (Rodrigues-Gil, 2010). Together with other senses, olfaction form flavor sense. We are able to identify smell after a certain process. First, after entering the nose, odor molecules dissolve in the olfactory epithelium. The olfactory epithelium is the mucosa found at the nasal cavity.

 An olfactory receptor binds inhaled molecules and then responds by directing impulses to the brain olfactory bulb. Every person has over 12 million olfactory receptors which help in responding to various smells. In the olfactory bulb, the information is sent to the frontal lobe and limbic system by the sensory receptors that transmit scent messages (Rodrigues-Gil, 2010). The frontal lobe helps in recognizing the smell. The limbic system, an ancient brain part, is responsible for associating the smell with emotions and memories.

For instance, when an individual walks into a chemical releasing industry, chemicals released in the air enters through the nose into the nostrils. The chemicals dissolve in the mucus. The olfactory epithelium detects the smell. This is why smell is said to begin at the back of the nose. The responsible neurons direct this message to the olfactory bulb. The sensory receptors which are part of the brain, send the information to the frontal lobe and to the limbic system. Then, these brain centers perceive the smell (Rodrigues-Gil, 2010). At this point, the individual has ability to perceive the smell of the chemicals released in the industry.

  • How do our senses to monitor our body’s position and movement. Discuss factors which may influence our vestibular senses. After you have fully and completely answered this question from a biological perspective, include a relevant example which illustrates your answer.

Sensory organs, that is, joints, eyes, and muscles and the vestibular system helps human beings in monitoring body position and keeping balance. The ear is important in monitoring the movement and position of our bodies. This is because the balance organ, the vestibular system, is found in the organ. The sensory system, the vestibular system, tells people whether they are falling, riding, or standing (Gray, 2019). The system has three tubes that are filled with fluid. They are known as the semi-circular canals. The system also has two otolith organs, saccule, and utricle. These canals end in a space with hair cells that are small known as ampullae.

The semi-circular canals have various responsibilities in terms of head movement direction. One canal responds to head turning sideways, the other tilting to the left or right, and the other one responds to the head tilting downwards or upwards (Gray, 2019). When the head makes a movement, the fluid in the canals makes a move too. This stimulates hairs cells. The hair cells then send information through nerves to the brain. The otolith organs help in detecting acceleration.

The information from the vestibular system is sent to other organs after being processed in the brain. Such organs include muscles, and eyes. This helps in knowing our body position and in maintaining balance. In case, contradictory messages are sent to the brain by sensory organs, it gets hard to keep our balance and one may feel dizzy or unwell (Gray, 2019). Vision, breathing proprioception and alignment of muscles, and vestibular function affects vestibular senses.

For instance, when someone rotates their head, a certain canal senses the movement, the fluid in the canal puts pressure against the sensory receptor (Gray, 2019). That receptor directs the impulses to the brain concerning the movement from the specifically stimulated canal. Information is processed and then sent to specific organs enabling this person to know their body position and maintaining balance.

  • What did the Gestalt psychologists contribute to our understanding of how the brain organizes sensation into perceptions? After you have fully and completely answered this question from a biological perspective, include a relevant example which illustrates your answer.

Gestalt psychologists provided principles through which people organize perceptions into perceptions. The psychologists explained that the brain creates perception which is more than the total sensory inputs that are available. The brain also does this in a predictable manner. These predictable ways were translated into principles. The Gestalts provided various demonstrations on how people organize perceptions into a whole. They also demonstrated that the whole is different from the sum of its parts (Wagemans et al., 2012). They helped us understand that the brain does more than just registering information about the environment.

            People always filter information from sensory organs and infer perceptions in a sensible manner. The Gestalt principles help people to understand why they see things the way they do. According to the principles, we are able to recognize an object by perceiving it first as different from the surrounding (Wagemans et al., 2012). We then bring form and order to the stimuli through organizing them into groups that are meaningful. This occurs through rules such as proximity, similarity, and continuity.

Gestalt psychologists helped us understand how we organize sensations into perception. For instance, with the law of proximity, Gestalts argue that objects that are near are mostly viewed as a group (Wagemans et al., 2012). This explains the argument that the whole is better. For instance, when we see a number of people seated together, we may immediately assume that they are a family or people from the same social group. In a bar, for instance, a waiter may see a group of people standing at a corner and direct them into one area where they can sit (Wagemans et al., 2012). This means that the waiter thinks these people are together yet they may be standing there looking at an unusual event happening around. Gestalt psychologists help us understand that we do not always focus on small component, rather, our brain perceives objects as elements of a system that is more complex.

  • How do the principles of figure-ground and moving contribute to our perception of form? Discuss how the roles of proximity, similarity, continuity, connectedness, enclosure impact the order and form of stimuli during the organizational process.

People have a tendency to segment the visual world into ground and figure. This is based on figure-ground principle. The figure, in this case, is the person or object with the visual field focus. The ground is the background. This means that perception of form can vary depending on what people perceive as ground and what they perceive as a figure. What people label as figure and ground determines their ability to interpret sensory information in a certain situation (Kathryn et al., 2019). This is why one person will identify a given figure as two faces while the other sees it as a vase.

According to Gestalt, the ability of people to discriminate against figures is guided by the principles of figure-ground and the other perception principles. During the organization process, proximity drives people into grouping together things that are close. People also use the similarity principle to group alike things. For instance, people watching a game group teams based on uniform colors. According to the continuity principle, people are more likely to perceive smooth and continuous lines rather than broken and jagged lines (Kathryn et al., 2019). Additionally, based on the principle of closure, people tend to organize perceptions into whole objects rather than into various parts.

Source: Kathryn et al., 2019.

For example, based on the ground-figure principle, what people label as figure and ground determines their ability to interpret sensory information in a certain situation. Focus on the faces in figure 1 would make the vase the background. Focus on the vase would make the faces the background. This shows that what you label as the background or the figure will determine how you interpret information (Kathryn et al., 2019). Similarly, good continuation, make people perceive figure 2 as two lines that are overlapping rather than four lines that are meeting at the center.

Source: Kathryn et al., 2019

Gestalts’ principles of perception help in explaining how people organize perceptions of form and how the order of stimuli is impacted during the organizational process.

  • How do we see the world in three dimensions? Be sure to discuss the research on visual cliffs, binocular cues, retinal disparity, and monocular cues.

Depth perception enables us to perceive in three dimensions the world. This is regardless of images that strike our eyes being two dimensional. It renders us capable of judging distance. According to research on a visual cliff, this ability is innate. This means that people are able to perceive things in three dimensions as soon after birth (Parker, 2016). Monocular cues enable people to judge depth through information acquired from one eye. The monocular cues include a relative height that is higher objects are very far, relative size that is smaller objects of the same size objects seem to be more distant, relative motion, linear perspective, and interposition where objects near tend to obstruct the view of objects that are farther away (Parker, 2016). These cues provide information essential for estimating spatial distances. They also help in perceiving the world in 3D.

Binocular cues need coordination of two eyes for depth perception. The cues include retinal disparity which involves the comparison of images from eyes’ retinas to figure out distance. The larger the variance between images being compared to the closer they are. The fact that the two eyes are located differently in the head causes the occurrence if retinal disparity. The perceiver tries unconsciously to harmonize the images in the best possible way (Parker, 2016). Still, the images oscillate known as a retinal rivalry. The degree to which retinal fusion occurs is dependent on image consonance or dissonance. The other cue is convergence.

For instance, varying lighting and shading provides information about object distances. This serves as a cue to the object distance from the perceiver. For example, brighter objects appear to be closer than darker objectives. This means that the manner in which light falls on an object and reflects its surface, as well as the shadows cast by that object, provides a cue for determining the position and shape of the object (Parker, 2016). Therefore, through monocular and binocular cues we can ascertain depth perception, distance, and size.

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