ZAPS

Split Brain

Severed corpus callosum Was a last-resort treatment for severe cases of epilepsy Severely limits communication between hemispheres Evidence for some hemisphere specializations of functions These "split-brain patients" can, for the most part, lead relatively normal lives. However, a classic experiment run by Michael Gazzaniga and his colleagues, revealed that the split-brain operation does change how these patients process information. What CAN they report? When a word is presented to the right visual field, the patient's left hemisphere can easily process the word (since most of our language abilities reside in the left hemisphere), direct the patient to say the word aloud, and cause the right hand to find the object behind the screens. HOW/WHY? Right hemisphere seems to have enough language capability to comprehend simple words of concrete objects, it does not have the phonological (speech) capabilities to allow the word of the object to be

Stroop Effect

a task designed to measure conflicts between two sensory inputs that is perhaps the mostly widely used and important of all cognitive tests Congruent trials: words and colors match. Incongruent trials: words and colors do not match. semantic interference - being distracted by the meaning of words Quiz: Based on the ideas presented in this ZAPS lab, under which of the following conditions do you think participants would be able to most quickly name the color in which the stimuli are written or drawn? Colored blobs Imagine you are a web designer working on an interactive website. You need a symbol to indicate to users that they will start a timed task. Based on the ideas presented in this ZAPS lab, which of the following symbols would be most effective for this purpose? Green go sign

Face Perception

prosopagnosia experience great difficulty with this task and fail to recognize the faces of others. QUIZ: 1. Which of the following statements most accurately describes the deficits of someone with prosopagnosia? "I see faces but I can never be sure of the identity of a person based on his or her face" 2. A region of the ________________ in the right hemisphere shows heightened activity levels when a person perceives upright faces. fusiform gyrus 3. We find it rather difficult to recognize inverted faces because inversion changes the relationships among individual facial features. true

Word Frequency

All the words you know are stored in your mental lexicon morphemes (the smallest meaningful unit of language) and that these morphemes serve as word primitives (the smallest form in which a word is stored in the mental lexicon) - Serial search models claim that when we see a word, we look through our lexical entries one entry at a time, to determine whether the item is a word or not. Then we retrieve the information about the word we need. High frequency words are at the "front" of the file drawer, and thus are encountered quickly as matches to targets. - Parallel access models (or direct access models) propose that a word activates multiple lexical entries simultaneously (or in parallel). The word that shares the most features with the word we perceive "wins". In parallel access models, high frequency words do not need as much activation to be recognized, and thus will "win" more quickly than low frequency words. QUIZ: 1. Imagine you have two friends majoring in English. Albany specializes in Shakespearean literature and Daisy specializes in 20th-century American literature. If they were both given Shakespeare's Macbeth to read, how would they most likely differ in their reading and comprehension of the play? Daisy would understand less & read more slowly than Abby 2. A person's mental lexicon is organized alphabetically, and functions like a virtual dictionary. True 3. When you prepared for tests with vast vocabulary lists (the SAT, for instance), you studied words and their meanings repeatedly so that you would be able to understand and use these words in context when necessary. By doing this, you were taking advantage of a phenomenon in lexical decision called _______________. Repetition priming

Ponzo Illusion

Otherly known as size/distance illusion Ponzo illusion demonstrates how the brain often relies on depth perception to guess at the properties of an object that it cannot directly sense. When asked to adjust the length of the bottom line to match the length of the top line, most people over-adjust, making the bottom line longer than the top the oblique (slanted) vertical lines provide the brain with distance cues by making the image appear three-dimensional This means that, when given two horizontal lines that are actually exactly the same length, the brain will perceive the top line as longer Quiz: 1. A psychological scientist asks study participants to indicate whether the green line at the front corner of the wall pictured here is longer than, shorter than, or equal in length to the green line at the back corner of the wall. Participants regularly say that the front line is shorter than the back line (even though the two are perfectly equal in length). The participants' brains are using ___________ to guide perception. Context clues about depth 2. The process we call perception involves our eyes sensing objects in the world and our brain interpreting the information that our eyes sense. Keeping this definition in mind, which of the following is a true statement about the Ponzo illusion? The brain leads us to perceive something that is not true 3. A real-life visual illusion is the "moon illusion." When the moon is close to the horizon, the full moon seems larger than it does when high in the sky. Rationally we know that the moon does not change size according to its position in the sky. Based on what you have learned about optical illusions, why do you think the moon illusion occurs? When the moon is near the horizon, objects on the earth which are near the moon on your retina, lead to a misperception of depth & size - the brain discerns the low moon as closer and thus BIGGER than the moon high in the sky.

Visual Search

Psychologist Donald Broadbent developed filter theory in 1958 to explain the selective nature of our attention, or conscious awareness. Selective attention filters enable us to make more automatic decisions about the stimuli around us, including which items to pay attention to during a visual search Anne Treisman's feature integration theory about attention and recognition, we begin a visual search by automatically indentifying "primitive" (or simple) features—such as color, shape, size, and movement—within an environment SEE PICTURE IN PHONE PHOTOS - DIFFERENCE BETWEEN FEATURE SEARCH & CONJUNCTION SEARCH QUIZ: 1. Based on the ideas presented in this ZAPS lab, which of the following tasks would you expect to be the most difficult visual search for someone to complete? Finding the 3 of spades in a deck of 52 playing cards that may vary by suit (hearts, diamonds, clubs, and spades) and number (aces, numbers 2-10, jacks, queens, kings)

Signal Detection

Psychophysics is an area of research that studies our psychological experience of physical stimuli Signal detection theory states that deciding whether a stimulus is present depends on: - the individual's sensitivity to the stimulus in the presence of other distracting stimuli or noise - the criteria used by the individual to make this judgment in ambiguous situations Response bias is a participant's tendency to respond to ambiguous stimuli in a certain way. In signal detection tasks, participants usually have a criterion they use as a "cutoff point" to determine when the signal is present versus when it is absent QUIZ: 1. A person with a conservative criterion for detecting a signal will generate a greater number of misses and ______________. correct rejections 2. Whether or not a person detects a stimulus depends only upon that person's absolute threshold. False 3. Researchers pay participants $15 for each response that is a hit and $2 for each correct rejection response. How might this affect a participant's response criterion? the response criterion will be more liberal

Selective Attention

Selective attention is our ability to focus on one input or task while ignoring others. A classic and deeply studied version of this is spatial cueing: using a cue to direct attention to a particular location in space, then testing whether detecting a stimulus is faster or slower in that location compared to other locations. QUIZ: 1. True or False: Shifting attention to a particular location in space requires that we move our eyes to fixate that location. true 2. In the experiment you just completed, why are participants usually slower to respond on invalid cue trials than on valid cue trials? they shift their attention in the direction of the cue, which is the correct direction on valid cue trials, but is the incorrect direction on invalid cue trials 3. Neuroscience evidence shows that attention works by... strengthening responses to attended stimuli at many levels of processing 4. Selective attention is our ability to... focus on one input or task while ignoring others

Attentional Blink

completely missed a critical part of your friend's story, and have no idea how to respond to her question. - selective attention, which is the ability to focus our attention on one event or piece of information, while blocking out background noise, or irrelevant stimuli. - divided attention, which is when our attentional resources are allocated to at least two tasks or pieces of information at once. QUIZ: 1. Studying for an important exam while watching television is not very efficient because it is an example of: divided attention 2. Our attentional systems cope with the overwhelming amount of information that we encounter on a daily basis by engaging in selective attention, and by extension, the attentional blink. true 3. Being able to drive a car while you carry on a conversation with a friend in the passenger seat is explained by: the ability to automatize driving and dedicate the majority of your attention to the conversation 4. Which of the following scenarios is an example of attentional blink? A waiter is telling 2 friends about the daily specials when a neighboring table erupts in laughter. The friends ask the waiter to repeat the last few items because their attention was diverted by the sudden loud laughs.