Chapter 2 - Questions Flashcards
Do Demonstration 2.1. Define “perception,” and provide an original example of perception. Define “object recognition,” “distal stimulus,” and “proximal stimulus.” What is sensory memory and the primary visual cortex?
Perception is the ability to obtain information and recognize stimuli presented to the senses. An example of perception is looking at a mug and recognizing it as a vessel to drink water.
Object recognition is when you notice an object as being separate from its background by combining the information obtained by your senses.
distal stimulus is an object that is “ out there” in the environment.
Proximal stimulus is the information obtained by your sensory receptors ( the image the object creates on your retina).
Sensory memory is a high capacity storage system that registers accurate information from each other the senses.
Primary visual cortex is the area located on the occipital lobe of the brain concerned with the processing of visual stimuli.
Describe the ambiguous figure-ground illusion and the illusory contour effect. What do these illusions indicate about visual perception?
The ambiguous figure-ground illusion display an image showcasing two forms that could be either figure or ground. In the case of the vase-faces picture, a person could identify a vase in the center with a plain background or two faces with a plain background.
The illusory contour effect showcases how we see a complete figure even though the lines might be inexistent or broken. For example, in an image of a tringle with empty spaces on the side, we will see a complete triangle.
Human perception is subjective. It is not only the information that we see but also the information we interpret.
Describe the following theories of object recognition, and explain the advantages and disadvantages of each:
- template matching theory - Idea that our visual system uses a set of templates, or information on patterns we have stored in our memory, and compare these to the stimulus to see which one matches it.
b. feature-analysis models - theory that visual stimulus is composed of features, or visual characteristics. - recognition-by-components model - a specific view of an object can be represented as a combination of #D shapes called geons. These can be combined to create objects.
Comment:Recognition-by-components and feature-analysis are closely related models with similar operations. The major difference lies in the unit of recognition (e.g., feature versus geons). These two models can also be described using the parallel distributed processing approach. Features (or geons) could exist as highly interconnected networks. The objects being recognized could be represented as the connection weights between the activated features (or geons).
Define and describe “bottom-up processing” and “top-down processing.” Give original examples of each type of perceptual processing.
Bottom-up processing is the process of obtaining information from the senses first and then this information continues to be process through other areas, for example: it starts on the retina, goes into prefrontal cortex and then into the fusiform face area. An example would be road signs, as we are constantly shown road signs as we are driving and we immediately react to the rules without processing the information first. We use the stimulus to make a decision and not interpret the stimulus and then sense it.
Top-down processing is information based on memory or previous knowledge. An example of top-down processing is when you read a sentence with spelling or grammar mistakes. Even though it may not be easy, you might still be able to interpret the meaning of the sentence because of your previous knowledge of how the words are actually spelled. The reason the top-down process is the dominant is that we need to rely on our previous knowledge to understand the meaning of the words, otherwise, if we are taking the stimulus as it is, the words might not make any sense.
Comment:Top-down processing and bottom-up processing are one of Matlin and Farmer’s five themes in the text. In the context of perception, these processes are used to describe how knowledge (input for top-down processes) and the external environment (input for bottom-up processes) are combined to recognize objects as old or new. The concepts of top-down and bottom-up processing are used in other cognitive domains, such as language comprehension. Note that, regardless of the domain, there are few instances in which top-down or bottom-up processing operate in isolation. However, in familiar contexts, top-down processing is more likely to dominate processing as we rely more on our knowledge and expectations, whereas in novel situations we are more likely to use bottom-up strategies. When you generate your examples of these processes, be sure that you can explain why top-down or bottom-up processing is the dominant process.
Do Demonstration 2.3. Briefly explain how top-down processing affects object recognition using this demonstration. What is “word superiority effect”? How is word superiority effect related to top-down processing?
Top-down processing affects this demonstration because only through our knowledge of the words we are able to understand the sentence and the letters in this sequence are not complete and we have to complete according to our knowledge which uses a similar shape to create an H or an A depending on the meaning we are able to interpret.
Word superiority effect is our ability to recognize letters when they are shown in a real, meaningful word as opposed to if they are shown by themselves or in a meaningless groups of letters.
You ability to recognize letters in words is based on your memory and previous knowledge and thus it is an example of top-down processing.
Describe the phenomenon known as “change blindness.” Do Demonstration 2.4. Define “inattentional blindness,” and indicate how it differs from change blindness. What do these effects indicate about the role of top-down processes in visual object recognition?
Change blindness is the difficult to recognize changes in an object or a scence
Inattentional blindness is when something out of the norm visibly appears in a scene while we are focused on another point in the same scene and we do not notice.
The role of top down processing is to help us be efficient when using our mental faculties. By focusing on the gist of the scene and not every little detail, we are not overloading ourselves with information. When a task is more demanding, such as focusing on a particular item in a scene, we might not notice a blatant change because we won’t be expecting this change and instead with are using our knowledge to stay focused on the task at hand.
How is face perception different from normal object recognition? Define “prosopagnosia.”What does the neuroscience research on face recognition indicate? Summarize the applied research on face recognition. What do these findings reveal about our object recognition skills?
Face recognition follow a whole approach in which the whole is more important than its parts. When you see a person, you recognizing by combining all the “ pieces” that makes a person face, together and this helps with recognizing the person. In addition, we rely on memory to recognize faces.
Prosopagnosia is a condition in which a person cannot recognize faces, but they are able to recognize objects.
Neuroscience research showcases that the temporal cortex, at the side of the brain, is the location most responsible for face recognition. An area in the lower portion of the cortex, called fusiform face area, is believed to be linked with face recognition. In addition, there seems to be indication from research that people can recognize upright faces more accurately than upside-down faces. This confirms that idea that face perception may follow a more holistic approach, similar to the Gestalt ideas, than isolated parts approach. People are also more prone to identifying familiar faces than unfamiliar faces, which might be due to their use of memory for perception. Another relevant research is in individuals with schizophrenia and face recognition. According to research, individuals with schizophrenia may have more difficulty recognizing faces, but this may not be necessarily related to face recognition only, but other problems with cognitive tasks.
Our object recognition skills are different than our facial recognition skills. Object recognition is done through parts of objects and facial recognition takes on a more holistic approach in which the whole face is seen as one piece in order for a person to recognize it.
Define “phonemes.” Describe the four characteristics of speech perception, including definitions for inter-speaker variability, coarticulation, phonemic restoration, and the McGurk effect. Do Demonstrations 2.5 and 2.6. What do these characteristics reveal about the complexity of speech perception?
Phonemes are the basic unit of sound in language.
Inter-speaker variability is the characteristics of speech that changes from person to person within the same language. For example, a person who speaks English and lives in California may speak some words differently than another English speaker from Alabama.
Coarticulation is the influence of surrounding phonemes on the phoneme being pronounced. The way you pronounce a phoneme may reflect this influence. For example the in idle and in don’t sound differently.
Phonemic restoration is a person’s ability to insert a missing phoneme that is missing based on the context of the whole sentence.
The McGurk effect relates the influence visual cues have on speech perception when both visual and auditory cues are present.
These characteristics showcase how individuals use a variety of clues and strategies to comprehend and perceive speech.
Describe the two theories of speech perception. Be sure that your answer includes a discussion of the phonetic module and categorical perception.
Some theorists believe that we humans must have a special mechanism in our nervous system that explains our impressive skill in speech perception. Others admire humans’ skill in speech perception, but they argue that the same general mechanisms that handle other cognitive processes also handle speech perception.
- special mechanism approach or speech-is-special approach
- humans are born with a specialized device that allows us to decode speech stimuli (Samuel, 2011). As a result, we process speech sounds more quickly and accurately than other auditory stimuli, such as instrumental music.
- involves the phonetic module; a special-purpose neural mechanism that specifically processes all aspects of speech perception; it cannot handle other kinds of auditory perception. This phonetic module would presumably enable listeners to perceive ambiguous phonemes accurately. It would also help you to segment the blurred stream of auditory information that reaches your ears, so that you can perceive distinct phonemes and words
- categorical perception: people tend to hear either one clear-cut phoneme or another rather than a sound partway.
- general mechanisms approaches
- we can explain speech perception without proposing any special phonetic module. Humans use the same neural mechanisms to process both speech sounds and non-speech sounds. Speech perception is therefore a learned ability, not really “special.”
- we know from the McGurk effect that speech is influenced by verbal cues, so it becomes more difficult to argue that a special phonetic module handles all aspects of speech perception.
- speech perception proceeds in stages and that it depends upon familiar cognitive processes such as feature recognition, learning, and decision making
