Perception - AP Psychology

The retina captures external light and converts it into visual images that are sent to the brain. The retina contains rods, which detect black and white, and cones, which detect color.

A big part of the way humans learn is by starting with a very general concept, and then organizing more detailed concepts within that general paradigm. This means that concepts we have learned before can influence new ideas and concepts that we are learning. When reading a sign, you use your previous knowledge of possible words and phrases, and put that together with the sensory knowledge you acquire from the sign.

Gestalt's principles do reference the phenomena of the mind making a whole based on small parts, but generally refers to visual construction as opposed to semantic meaning.

Prosopagnosia can be either congenital or acquired. Congenital cases are more rare, and the most difficult to treat. Acquired prosopagnosia usually results from damage to the occipito-temporal lobe. The fusiform gyrus has been shown to activate in response to faces in several different neuro-psychological studies. This disorder is famously chronicled in the novel "The Man Who Mistook His Wife for a Hat" by Oliver Sacks.

Our brains use the differences in the location of an object on our retinas in order to judge their relative distance from one another. This requires two eyes, and thus is binocular. The other cues listed require only one eye (monocular).

Gate-control theory posits that the spinal cord contains a "gate" that controls whether pain signals get sent to the brain or not. This "gate" is opened based on the strength of the pain signals from the body.

Figure-ground is a perception used to distinguish a figure from its background, whether that be black words on a white page or distinguishing a particular voice from a crowd. There are many cues that enable us to distinguish a figure from its background, like color, shapes, edges, movements, or sounds. Figure-ground perception is a part of “Gestalt principles," or the prcoess of evaluating the bigger picture.

Retinal disparity is a binocular cue that involves observing the difference between the two images the retinas receive of a single object. The greater the difference, the closer the object is to the viewer.

Justin can physically speak, so we can rule out Broca's area, which is in the frontal lobe. However, he is unable to understand language, which is handled by Wernicke’s area. Wernicke’s area is located in the temporal lobe.

Transduction occurs when sensations are perceived. In the case of touch, our fingers detect pressure which is translated into a neural impulse, causing our brain to perceive that we have made contact with a surface.

Proximity, closure, similarity, and continuity are four of the Gesalt rules for perception, whereas difference (the opposite of similarity) is not. Proximity states that groups of objects close together are likely to be grouped together, closure is the tendency to fill in the gaps in a visual scene, similarity describes how objects that look similar are likely to be grouped together, and continuity states that objects with similar orientations are likely to be grouped together.

Figure-ground is one tool our brains use to form perception. This is the organization of the visual field by separating an object (figure) from its surroundings (ground). In this scenario, the apple stands out from the grapes it's surrounded by; therefore, this would make the apple the figure and the grapes the ground. Another example would be a lead singer versus the rest of a band. The lead singer stands out as a separate object, making this individual the figure. The rest of the band would be considered the ground relative to the lead singer.

Binocular cues are depth cues that require the use of two eyes. For instance, trying to touch the tip of two pencils together in front of your face may be rather easy to do with both eyes open; however, attempting this task with one eye open is significantly challenging. Retinal disparity is a binocular cue used to perceive depth between two near objects. It does so by comparing the different images from both retinas. Each eye receives different images because they are usually around two and half inches apart. The greater the difference (disparity) there is between the images, then the closer the object will be. The other options would be incorrect because they are defined as monocular cues.

Color constancy is when a familiar object may be perceived as having a consistent color regardless of the changing wavelengths reflecting off its surface. It may be an abstract idea for some, but it's important to remember that an object does not contain color itself. Instead, we perceive objects as certain colors because of the wavelengths they reflect. In terms of color constancy, our brains are able to recognize the same color despite different illuminations by taking into consideration the light reflecting off the object relative the objects surrounding it.

Weber's Law states that a change in stimulus that is barely noticeable for a particular person will be a constant ratio of the original stimulus. For a 10-pound weight, the man would start noticing a change when 0.5 pounds was added. Anything less than that, he would not notice. For a 100-pound weight, the man would not notice a 0.5-pound weight change; rather, he would notice a 5-pound weight change since this is the same proportion as observed in the original situation.

The cocktail party effect primarily applies to auditory stimuli, and Gestalt perceptual laws would not explain how one finds an object among lots of similar objects. Top-down processing begins with your knowledge about the situation, which you apply to the current context and use to guide your ability to correctly identify the flamboyant figure. That is, you first remember you are looking for—the figure—and then try to locate a stimulus you can identify as being flamboyant. Bottom-up processing begins with the sensations you experience, which are passed “up” from your retina—via vision—to higher and higher brain areas that can carry out more and more complex analysis.

Sensation is best understood as simply the stimulation of sensory organs (in this case sight). Perception has to do with selecting, organizing, and interpreting sensory input in a meaningful way. One can sense the features of a stop sign; however, in order to perceive what a stop sign is, one must interpret what the sensory input means. The visual cortex is the portion of the brain that is most likely to process visual stimuli. Learning might be involved in perception; however, the best answer is "sensation. . . perception."

The trichromatic theory is the oldest theory to explain why and how humans see color. It posits that there are three types of cone receptors in the retina, one type for each of the primary colors (e.g. red, blue, and yellow).

“Retinal disparity” is a binocular depth cue, not a monocular cue. The other answers—relative size cue, texture gradient, and linear perspective—are all monocular cues.

The opponent-process theory of color vision posits that colors are processed in pairs of chromatic opposites. This theory explains why the suffusion of reddish hues from the direct sunlight though Lucia’s eyelids left an afterimage of bluish color in their absence. The trichromatic theory of color vision attributes the discernment of color to specializations of the eye’s cones and does not account for negative afterimages. Gestalt theory concerns the perception of parts and wholes. Inattentional blindness is not a theory, but a phenomenon in which objects that are plainly available in an individual’s perceptual field nonetheless go unnoticed due to a lack of attention paid to them.

The situation with Angela is the best example of synesthesia—a phenomenon, in which stimulation of one sensory pathway triggers a response by a different, unrelated sensory pathway. People with synesthesia might see a certain color whenever they taste a certain food. The important thing to note is that in synesthetic perception, the person experiences the synesthetic connection as being projected outside the body, not just in the mind’s eye (e.g. Angela does not simply imagine the color red when she sees the letter A: she actually sees A as being colored red, even if it is printed in plain black font). The other situations described in the answer choices reflect other psychological phenomena. Ashley is experiencing amnesia; George, phantom limb syndrome; and Taylor, taste aversion.