Sensation & Perception - GRE Subject Test: Psychology

Sensorineural hearing loss is permanent and often results from the loss or damage to hair cells or the nerve from the ear to the brain. For this reason, it occurs from damage to the inner ear, where the nerve and hair cells are located. Damage to the middle ear would result in conductive hearing loss. Damage to the outer ear, would likely result in decreased sound localization.

Sound waves are pressure changes and loudness is related to the amplitude of the wave. It is quantified by the decibel (dB). Pascal is the standard unit for pressure. Whereas, Hertz is used to quantify frequencies and an octave is a doubling in frequency. Meters/second describes the speed at which sound propagates.

Hearing aids replace the cochlea and the essential apparatuses contained within. Most significantly, they perform the role of the receptor cells lining the basilar membrane within the cochlea, which are responsible for the transduction of information carried by physical energy into electrical energy within the nervous system. This type of hearing aid is of value to an individual suffering from conduction deafness, which is deafness brought about due to damage to the apparatuses of the ear. An example of this would be a soldier deafened by exploding ordinance, or an airport worker continuously exposed to the loud volume of plane engines without sufficient ear protection. Cortical deafness, also known as nerve or sensorineural deafness, however, is brought about through damage to the auditory regions of the nervous system. As such, an individual with perfectly healthy ears might be rendered deaf due to damage caused by a stroke or brain trauma. This kind of deafness cannot be rectified by hearing aids, or any other form of extant medical intervention. "Ossicle" may refer to the bones of the inner ears (the auditory ossicles), but is not itself the name for a form of deafness nor is "auditory."

The pinna is the formal term for the body part that is commonly referred to as the 'ear'. This is the portion of the ear that projects from the head. This is the first point of contact with air vibrations that will enter the ear canal to pass their vibrations onto the eardrum. The tympanic membrane the formal term for the eardrum. From here, the auditory ossicles are vibrated. These are the three, minute bones found within the middle ear: the malleus, incus, and stapes. These three bones transmit the vibrations onto the oval window of the cochlea, which contains the basilar membrane, where transduction of the physical information occurs.

Thus the correct order is: pinna, tympanic membrane, auditory ossicles, and cochlea.

The frequency of a vibration corresponds to the pitch of the perceived sound produced from it. Higher frequencies will produce higher pitched notes, while lower frequencies will produce lower pitched notes. On the other hand, the amplitude of a sound wave will determine the volume of a perceived sound. Timbre is a complex component of a sound, and is the result of a variety of other elements. To provide a brief illustration however, timbre explains why a G# note on a trumpet sounds distinct from a G# note played on a piano. The longevity of a note is not the result of either the frequency or the amplitude of a sound. This is simply determined by how long the vibration continues.

The frequency of a sound wave, or the pace of its vibrations within the ear, will determine the sound's pitch. The sound's loudness is determined by the amplitude of the sound wave, the timbre by its complexity.

Addison's disease, a chronic disorder of the endocrine system, is caused by an inability of the adrenal glands to produce sufficient steroid hormones (specifically, two types of necessary natural corticosteroids). In addition to causing renal insufficiency and muscle weakness, Addison's has been known to idiopathically—through an unknown mechanism—hyper-sensitize one or more senses in the body, most commonly taste.

The receptors for salty and sour are believed to be ion sensors. MSG stimulates receptors corresponding to unami. PROP causes an intense bitter sensation in "supertasters." Sweet and bitter receptors are believed to be similar to odorant receptors because molecules dock on transmembrane receptors in order to initiate an action potential.

There are about three hundred and fifty receptor types involved in olfaction. Each receptor responds to more than one molecule, but with different strengths. Receptors make their first synapse with glomeruli, but each glomerulus receives input from only one type of receptor.

Assuming that a food critic or wine taster most values their ability to perceive the flavors and aromas of these consumable items, then a loss of their sense of smell—olfactory loss—would be the greatest of these misfortunes they could suffer. The vestibular sense is that which informs us as to the orientation of our bodies in space. The semicircular canals contribute to this sense, and are housed within the inner ears. The loss of this sense might not compromise a food critic or wine taster as severely in their professional life. The striate cortex is a key component of the visual cortex, and damage therein would likely result in partial or total blindness. This would not hinder the food critic or wine taster's abilities to perceive their foods or wines however.

In 1709, George Berkeley noted various depth cues in the human visual system, including interposition, which refers to the depth cue wherein one object covers or overlaps with another object. A second cue is motion parallax wherein the disparity in speed and motion gives us cues about the relative depth of parts of the object. The last cue is binocular disparity, also known as stereopsis. This cue is linked to the fact that our different eyes provide us with two slightly different views of the world around us. When the brain adds together these two images, we get a perception of depth.

The correct answer is the process of combining different sensory signals. To give cause or equal opportunity to each sense and a mathematical technique for computing definite integrals of one real variable are answers that utilize the incorrect definition of integration for this problem. When a mixture of lights add together and create the perception of color is additive color mixture.

The somatosensory system is a sense system based around information about the physical body. This includes the senses of touch, of heat, of pain, pressure, and vibration; of orientation and balance; and of muscular movement. The tactile and skin senses, the vestibular sense, and the kinesthetic sense comprise it. The tactile sense is that of touch. Other skin senses include detection of heat, pain, pressure, and vibration. The vestibular sense is that which detects the body's orientation in space, and contributes to our sense of balance and motion. The kinesthetic sense is based off the movements and positions of our muscles, and may also be referred to as proprioception. This sense is how we can close our eyes yet remain aware of where our limbs are positioned in space, or why we don't need to follow our legs and arms with our eyes to direct them while we walk or reach for objects out of view. The other answer choices do not involve correct groupings of senses to summarize the somatosensory system.

The Moro reflex (also called the "startle reflex") generally lasts in newborns until the age of six months. When startled, a newborn exhibiting the Moro reflex will throw its head back and its arms and legs out simultaneously, cry, then pull its limbs back in.

Macular degeneration is a degenerative condition affecting the retina and choroid—the blood supply that feeds the retina. In either "dry" or "wet" forms, it causes progressive central blindness while leaving the peripheral vision largely intact. It is estimated that from 40-55 million people worldwide suffer from the condition, which is suspected to have been long under-diagnosed.

The interpretation of sensory stimuli is an important biological process. Feature detectors play an important role in the sense of sight. Once visual signals reach the primary visual cortex, specialized visual cells called "feature detectors" code for the elements of stimuli that are most important.

Saccades can occur voluntarily or involuntarily. The voluntary saccades allow you to rapidly change fixation from one object to another. This action allows you to read by rapidly changing your fixation on different words and locations on the page. Vergence is when two eyes move in the opposite direction, this would not allow you to focus on the words on the page, making reading impossible (trying to read while "crossing" your eyes). Smooth pursuit is when the eyes smoothly follow a moving object, words on a page are stationary in most situations. Reflexive eye movements are involuntary whereas reading is a voluntary action.

The magnocellular system is colorblind and it carries low spatial frequency information and high temporal frequency information in the more dorsal regions of the posterior half of the brain. This means the visual information it carries is about large, fast things leading to the processing of information about location. The other answer options pertain to the parvocellular system.

Glaucoma is caused by pressure due to the blockage of flow of aqueous liquid. Therefore, detection of pressure build-up before it damages the optic nerve head is the correct prevention method. Injection of anti-vascular drugs is used for Macular degeneration that is detected early enough. Control of your diet and blood pressure may delay peripheral degeneration and diabetic retinopathy. Antibiotics and hygiene can prevent blindness caused by Trachoma.