Ch. 5 Flashcards

Question

How Many Items Can Be Held in Short-Term Memory?

Answer 1

According to measurements of digit span, the average capacity of STM is about five to nine items. Luck and Vogel concluded that participants were able to retain about four items in STM. Thus, chunking in terms of meaning increases our ability to hold information in STM. increases the memory span to 20 words or more

Answer 2

Detecting differences between pictures or displays that are presented one after another. More recent measures of STM capacity have set the limit at about four items (Cowan, 2001). This conclusion is based on the results of experiments like one by Steven Luck and Edward Vogel (1997), which measured the capacity of STM by using a procedure called change detection . The result of Luck and Vogel’s experiment, indicates that performance was almost perfect when there were one to three squares in the arrays, but that performance began decreasing when there were four or more squares. Luck and Vogel concluded that participants were able to retain about four items in STM. Other experiments, using verbal materials, have come to the same conclusion (Cowan, 2001).

Answer 3

Combining small units into larger ones, such as when individual words are combined into a meaningful sentence. Chunking can be used to increase the capacity of memory. These 7 or 4 item estimates set rather low limits on the capacity of STM. If our ability to hold items in memory is so limited, how is it possible to hold many more items in memory in some situations, such as when words are arranged in a sentence? = chunking Thus, chunking in terms of meaning increases our ability to hold information in STM. increases the memory span to 20 words or more.

Answer 4

Used in connection with the idea of chunking in memory. A chunk is a collection of elements that are strongly associated with each other but weakly associated with elements in other chunks.

Answer 5

Any memory strategy or technique that improves encoding, retention, and/or retrieval of information. Story mnemonic: put random words into a meaningful order within a story that can then be more easily remembered.

Answer 6

Some researchers have suggested that rather than describing memory capacity in terms of “number of items,” it should be described in terms of “amount of information.” When referring to visual objects, information has been defined as visual features or details of the object that are stored in memory. The results, was that participants’ ability to make the same/different judgment depended on the complexity of the stimuli.

Answer 7

did an experiment using Luck and Vogel’s change detection procedure. But in addition to colored squares, they also used more complex objects like the ones. For ex, shaded cubes, which were the most complex stimuli, a participant would see a display containing several different cubes, followed by a blank interval, followed by a display that was either the same as the first one or in which one of the cubes was different. The participant’s task was to indicate whether the two displays were the same or different. The results, was that participants’ ability to make the same/different judgment depended on the complexity of the stimuli. Memory capacity for the colored squares was 4.4, but the capacity for the cubes was only 1.6. Based on this result, Alvarez and Cavanagh concluded that the greater the amount of information in an image, the fewer items that can be held in visual STM.

Answer 8

suggest that the capacity for STM may serve a functional purpose: to help us predict future sensory input. This means our leaky bucket likely leaks on purpose at least!

Answer 9

A limited-capacity system for temporary storage and manipulation of information for complex tasks such as comprehension, learning, and reasoning. introduced in a paper by Baddeley and Hitch (1974). STM is concerned mainly with storing information for a brief period (for example, remembering a phone number), whereas WM is concerned with the manipulation of information that occurs during complex cognition. holding information in memory and processing information. The fact that STM and the modal model do not consider dynamic processes that unfold over time is what led Baddeley and Hitch to propose that the name working memory, rather than short-term memory, be used for the STM process.

Answer 10

Baddeley, one of the things he noticed was that under certain conditions it is possible to carry out two tasks simultaneously. According to Atkinson and Shiffrin’s modal model, it should only be possible to perform one of these tasks, which should occupy the entire STM. found participants were able to read while simultaneously remembering numbers. What kind of model can take into account both (1) the dynamic processes involved in cognitions such as understanding language and doing math problems and (2) the fact that people can carry out two tasks simultaneously? Baddeley concluded that working memory must be dynamic and must also consist of several components that can function separately. He proposed three components: the phonological loop, the visuospatial sketch pad, and the central executive

Answer 11

three main components of Baddeley and Hitch’s (1974; Baddeley, 2000) model of working memory: the phonological loop, the visuospatial sketch pad, and the central executive.

Answer 12

The part of working memory that holds and processes verbal and auditory information. consists of two components: the phonological store , which has a limited capacity and holds information for only a few seconds, and the articulatory rehearsal process , which is responsible for rehearsal that can keep items in the phonological store from decaying. Thus, when you are trying to remember a telephone number or a person’s name you are using your phonological loop.

Answer 13

The part of working memory that holds and processes visual and spatial information. When you form a picture in your mind or do tasks like solving a puzzle or finding your way around campus, you are using your visuospatial sketch pad. The phonological loop and the visuospatial sketch pad are attached to the central executive. The visuospatial sketch pad handles visual and spatial information and is therefore involved in the process of visual imagery.

Answer 14

The part of working memory that coordinates the activity of the phonological loop and the visuospatial sketch pad. The “traffic cop” of the working memory system. where the major work of working memory occurs. The central executive pulls information from LTM and coordinates the activity of the phonological loop and visuospatial sketch pad by focusing on specific parts of a task and deciding how to divide attention between different tasks. The central executive is therefore the “traffic patrol” of the working memory system. _{To understand this “traffic patrol” function, imagine you are driving in a strange city, a friend in the passenger seat is reading you directions to a restaurant, and the car radio is playing music in the background. Your phonological loop is taking in the verbal directions from your friend; your sketch pad is helping you visualize a map of the streets leading to the restaurant; and your central executive is coordinating and combining these two kinds of information. In addition, the central executive might be helping you ignore the lyrics from the music on the radio so you can focus your attention on the directions.}

Answer 15

the phonological similarity effect, the word length effect, and articulatory suppression.

Answer 16

An effect that occurs when letters or words that sound similar are confused. For example, T and P are two similar-sounding letters that could be confused. R. Conrad (1964) flashed a series of target letters on a screen and instructed his participants to write down the letters in the order they were presented. He found that when participants made errors, they were most likely to misidentify the target letter as another letter that sounded like the target. Thus, even though the participants saw the letters, the mistakes they made were based on the letters’ sounds.

Answer 17

The notion that it is more difficult to remember a list of long words than a list of short words. Each list contains eight words, but according to the word length effect, the second list will be more difficult to remember because it takes more time to pronounce and rehearse longer words and to produce them during recall (Baddeley et al., 1984). In another study of memory for verbal material, Baddeley and colleagues (1975) found that people can remember the number of items that they can pronounce in about 1.5 to 2.0 seconds. Try counting out loud, as fast as you can, for 2 seconds. According to Baddeley, the number of words you can say should be close to your digit span.

Answer 18

Interference with operation of the phonological loop that occurs when a person repeats an irrelevant word such as “the” while carrying out a task that requires the phonological loop. Another way that the operation of the phonological loop has been studied is by determining what happens when its operation is disrupted. Baddeley and colleagues (1984) found that repeating “the, the, the . . .” not only reduces the ability to remember a list of words but also eliminates the word length effect. Eliminating rehearsal by saying “the, the, the . . .” removes this advantage for short words, so both short and long words are lost from the phonological store.

Answer 19

A type of mental imagery involving vision, in which an image is experienced in the absence of a visual stimulus. early visual imagery experiment by Roger Shepard and Jacqueline Metzler (1971). measured participants’ reaction time to decide whether pairs of objects were the same or different, they obtained the relationship for when objects that were the same. when one shape was rotated 40 degrees compared to the other shape, it took 2 seconds to decide that a pair was the same shape. However, for a greater difference caused by a rotation of 140 degrees it took 4 seconds. Based on this finding that reaction times were longer for greater differences in orientation, Shepard and Metzler inferred that participants were solving the problem by rotating an image of one of the objects in their mind, a phenomenon called mental rotation. This mental rotation is an example of the operation of the visuospatial sketch pad because it involves visual rotation through space.

Answer 20

Just as the operation of the phonological loop is disrupted by interference (articulatory suppression), so is the visuospatial sketch pad. Which was easier, pointing to “Out” or “In” or saying “Out” or “In”? Most people find that the pointing task is more difficult. The reason is that holding the image of the letter and pointing are both visuospatial tasks, so the visuospatial sketch pad becomes overloaded. In contrast, saying “Out” or “In” is an articulatory task that is handled by the phonological loop, so speaking typically does not interfere with visualizing the F.

Answer 21

The central executive is the component that makes working memory “work,” because it is the control center of the working memory system. Its mission is not to store information but to coordinate how information is used by the phonological loop and visuospatial sketch pad. Baddeley describes the central executive as being an attention controller. It determines how attention is focused on a specific task, how it is divided between two tasks, and how it is switched between tasks. The central executive is therefore related to executive attention. The central executive is essential in situations such as when a person is attempting to simultaneously drive and talk on the phone. One of the ways the central executive has been studied is by assessing the behavior of patients with injury to the brain. the frontal lobe plays a central role in working memory. It is logical, therefore, that patients with damage to the frontal lobe have problems controlling their attention. A typical behavior of patients with frontal lobe damage is perseveration —repeatedly performing the same action or thought even if it is not achieving the desired goal.

Answer 22

Baddeley’s three-component model cannot explain some things. A component added to Baddeley’s original working memory model that serves as a “backup” store that communicates with both long-term memory and the components of working memory. It holds information longer and has greater capacity than the phonological loop or visuospatial sketch pad. Can store information (thereby providing extra capacity) and is connected to LTM (thereby making interchange between working memory and LTM possible). Model also shows that the visuospatial sketch pad and phonological loop are linked to LTM. This revised model shows connections to three types: - The phonological loop is connected to language-related LTM, including definitions, grammar, syntax (word order), and phonology (how languages sound). - The episodic buffer is connected to episodic LTM, or the memories of our conscious experiences. - The visuospatial sketch pad is connected to visual semantics, a type of LTM related to the meaning derived from visual information.

Answer 23

Phineas Gage and the tamping rod. Amazingly, Gage survived, but reports from the time noted that the accident had changed Gage’s personality from an upstanding citizen to a person with low impulse control, poor ability to plan, and poor social skills. Nonetheless, reports about Gage, whether accurate or not, gave rise to the idea that the frontal lobes are involved in a variety of mental functions, including personality and planning.

Answer 24

A task in which information is provided, a delay is imposed, and then memory is tested. This task has been used to study short-term memory by testing monkeys’ ability to hold information about the location of a food reward during a delay. If their PFC is removed, their performance drops to chance level (50/50), so they pick the correct food well only about half of the time. This result supports the idea that the PFC is important for holding information for brief periods. In fact, it has been suggested that one reason we can describe the memory behavior of very young infants as “out of sight, out of mind” (when an object that the infant can see is then hidden from view, the infant behaves as if the object no longer exists) is that their frontal and prefrontal cortex do not become adequately developed until about 8 months of age

Answer 25

Shintaro Funahashi and colleagues (1989) conducted an experiment in which they recorded from neurons in a monkey’s PFC while the monkey carried out a delayed-response task. The monkey first looked steadily at a fixation point, X, while a square was flashed at one position on the screen. This caused a small response in the neuron. After the square disappeared, there was a delay of a few seconds. The nerve firing records show that the neuron was firing during this delay. This firing is the neural record of the monkey’s working memory for the position of the square. After the delay, the fixation X disappeared. This was a signal for the monkey to move its eyes to where the square had been flashed. The monkey’s ability to do this provided behavioral evidence that it had, in fact, remembered the location of the square. The key result of this experiment was that Funahashi found neurons that responded only when the square was flashed in a particular location and that these neurons continued responding during the delay.

Answer 26

Short-term changes in neural network connectivity that has been hypothesized as a mechanism for holding information in working memory. proposed by Mark Stokes (2015). the activity state, in which information to be remembered causes several neurons to briefly fire. This firing does not continue but causes the synaptic state, in which several connections between neurons are strengthened. These changes in connectivity, which Stokes calls activity-silent working memory, last only a few seconds, but that is long enough for working memory. Finally, when the memory is being retrieved, the memory is indicated by the pattern of firing in the network. Thus, in Stokes’s model, information is held in memory not by continuous nerve firing but by a brief change in the connectivity of neurons in a network.

Answer 27

These models are based on experiments and computations too complex to describe here, and all are speculative. However, they suggest that information can be stored in the nervous system by changes in the connections in neural networks. Another current idea about working memory is that it involves physiological processes that extend beyond the PFC. This idea that several regions of the brain are involved in working memory is an example of distributed representation.

Answer 28

carried out one of the early experiments on individual differences in working memory capacity by developing a test for working memory capacity and then determining how individual differences were related to reading comprehension. The test they developed, the reading span test required participants to read a series of 13- to 16-word sentences. Each sentence was seen briefly as it was being read, and then the next sentence was presented. Immediately after reading the last sentence, the participant was asked to remember the last word in each sentence in the order that it occurred. The participant’s reading span was the number of sentences they could read, and then correctly remember all of the last words. Participants’ reading spans ranged from 2 to 5, and the size of the reading span was highly correlated with their performance on several reading comprehension tasks and their verbal SAT scores. concluded that working memory capacity is a crucial source of individual differences in reading comprehension.

Answer 29

focused on one component of working memory: the control of attention by the central executive. They first separated participants into two groups based on their performance on a test of working memory. Participants in the high-capacity group were able to hold a greater number of items in working memory; participants in the low-capacity group were able to hold fewer items in working memory. Participants were tested using the change detection procedure. Their task was to indicate whether the cued red rectangles in the test display had the same or different orientations than the ones in the memory display. While they were making this judgment, a brain response called the event-related potential was measured, which indicated how much space was used in working memory as they carried out the task. the size of the ERP is nearly the same for both groups. However, Vogel also ran another condition in which he added some extra blue bars. These bars were not relevant to the participant’s task, so their purpose was to distract the participant’s attention. If the central executive is doing its job, these extra bars should have no effect, because attention would remain focused on the red bars. The results, show that adding blue bars caused an increase in the response of the high-capacity group but caused a larger increase in the response of the low-capacity group. The fact that adding the blue bars had only a small effect on the response of the high- capacity group means that these participants were very efficient at ignoring the distractors, so the irrelevant blue stimuli did not take up much space in working memory. Because allocating attention is a function of the central executive, this means that the central executive was functioning well for these participants. The fact that adding the two blue bars caused a large increase in the response of the low-capacity group means that these participants were not able to ignore the irrelevant blue stimuli, so the blue bars were taking up space in working memory. concluded from these results that some people’s central executives are more efficient at allocating attention than others.

Answer 30

better because they are better at “tuning in” to the important stimuli or better at “tuning out” the irrelevant distractor stimuli. The conclusion from these experiments has generally been that high-capacity participants are better at tuning out the distractors. The importance of being able to ignore distracting stimuli highlights the connection between working memory and cognitive control. Cognitive control has been described as a set of functions, which allow people to regulate their behavior and attentional resources, and to resist the temptation to give in to impulses. In other words, cognitive control involves effective use of endogenous attention while limiting or suppressing exogenous attention.

Ch. 5 Flashcards

(54 cards)