Working Memory

Working memory is the brief, immediate memory for material that you are currently processing; a portion of working memory also coordinates your ongoing mental activities (Matlin, 2005, Ch. 4). One classic theory, the “Magical Number Seven," was developed by George Miller. Miller suggested that people can remember about seven items, give or take two. Miller used the term chunk to describe the basic unit in short-term memory. More recently, Nelson Cowan proposed that this number is actually closer to four. Click here to read more about Cowan’s theory.

Two sets of researchers, John Brown and Lloyd and Margaret Peterson, established that material held in memory for less than a minute is frequently forgotten. The Brown/Peterson & Peterson research technique involved quickly memorizing 3 letters, counting backgrounds, and then attempting to recall the letters. This early research underscored the fragile nature of memory stored for just a few seconds. The Brown/Peterson & Peterson technique inspired hudreds of studies on short-term memory and increased support for the cognitive approach (versus the behaviorist approach) (Matlin, 2005).

Another technique often used to examine short-term memory makes use of the serial position effect, which establishes that recall is better for items at the end of the list (recency effect) and at the beginning of the list (primacy effect). Therefore, the serial position of the stimuli plotted against probability of recall tends to form a U-shaped curve. However, a number of more recent studies that used visual–spatial stimuli (computer-constructed pattern of dots) have reported an absence of primacy effect and a limited recency effect (Broadbent & Broadbent, 1981; Frick, 1988; Hines, 1975; Phillips & Christie, 1977; Potter & Levy, 1969 referenced by Tremblay, Parmentier, Geraud, Nicholls, & Jones, 2006). To further test this observation, the Tremblay team tested whether the classical modality effect —- that is, the stronger recency effect for auditory items relative to visual items —- can be extended to the spatial domain. Computer simulations were done for visual-spatial (dot patterns), visual-verbal (letter patterns), and visual-auditory (letters spoken in a monotone male voice) tasls. The results demonstrated a modality effect —- greater recency in the auditory than in the visual modality -—in the recall of verbal items but not of spatial items. The results also suggested that the recency effect is stronger in the auditory modality than in the visual modality.

Working memory research led to the concept of proactive interference, which means that people have trouble learning new material because previously learned material keeps interfering with new learning. A recent study shows that older adults have the same mental acuity as younger people, but they have less room in working memory to handle additional information. Read the Developmental Psychology article by clicking here.

As researchers were contributing to the body of knowledge on working memory, there was still no comprehensive theory for this brief kind of memory – not until a cognitive psychologist, Alan Baddeley, developed his model of working memory.



Baddeley likened his model to a workbench where material is constantly being handled, combined, and transformed. The workbench holds both new material and old material that you have retrieved from storage, or long-term memory. A recent NASA study examines the “switch cost” in terms of time for the Central Executive to switch between cognitive tasks. Click here to read more.

Another study by Vladimir Sloutsky and Anna Fisher (Grabmeier, 2004) is interesting because the results run counter to the popular belief that people's working memory peak out at young adulthood. The researchers counter that very young children tend to similarity-based induction when examining pictures, whereas adults use category-based induction (or top-down processing using feature comparison model, or prototype approach). Click here to read more.

A healthy working memory is the ideal; however, for various reasons, many people have a deficit of working memory. Dr. Glenda Thorne discusses working memory deficits and how they can impact students. Students with working memory deficits may have problems following directions, solving math problems that have multiple steps. They may forget sentences they just read resulting in poor reading comprehension. Writing is arduous, as it involved the simultaneous retrieval of thoughts from long-term memory and organization of thoughts into grammatically correct sentences. Higher order thinking such as problem solving also suffers, since it involves holding components of the problem in mind while generating solutions. Click here to read the entire article.

Perception

When we perceive, we use our previous knowledge to gather and interpret stimuli registered by our senses. Typically, we gather stimuli by seeing (visual) or hearing (auditory). Visual object recognition allows us to identify a complex arrangement of sensory stimuli. Gestalt psychology is a historical approach to psychology. One main principle of Gestalt is that humans have the tendency to organize what they see into pattterns rather than random arrangements. Look at the picture below. What do you see?



You probably see a human face rather than simply an oval and two straight lines. This figure has Gestalt, or an overall quality that transcends the individual elements.

More modern theories of visual object recognition include template-matching theory, feature-analysis theory, and recognition-by-components theory.

With template-matching theory, you compare a stimulus with a set of templates, or patterns that you have stored in memory. An example is the variability of letter shapes. We can easily read the words below, even though they are in different fonts.



Feature-analysis theory proposes that a visual stimulus is composed of a small number of characteristics, each being a distinctive feature. For example, a table has four legs and a flat surface.



Recognition-by-components assumes that a given view of an object can be represented as an arrangement of simple 3-D shapes called geons. For example, a mug consists of a straight upright cylinder and another curved cylinder for a handle.



The above types of visual object recognition are all examples of bottom-up processing, where the physical stimuli from the environment are registered on the sensory receptors. Another type of processing is top-down processing, which emphasizes how a person’s concepts and higher-level mental processes help in identifying objects. Top-down processing particularly influences the ability to recognize words during reading. See how easy it is to read the paragraph below, even though only the first and last characters of each word are positioned correctly.

Aoccdrnig to rseearch at Cmabrigde Uinervtisy, it deosn’t mttaer in what oredr the ltteers in a wrod are, the olny iprmoatnt thing is taht the frist and lsat ltteer be at the rghit pclae. The rset can be a total mses and you can sitll raed it wouthit porbelm. This is bcuseae the human mind deos not raed ervey lteter by istlef, but the wrod as a wlohe.

We use context and previous knowledge to make meaning of these strings of characters in between. So you see, both bottom-up and top-down processes must work together to allow us to recognize objects such as words in print.

Recent research has begun to pinpoint the areas of the brain associated with bottom-up and top-down processing. One such study done at Ohio State University (Sarter, Givens, & Bruno, 2000) measured the brain’s activation during sustained attention (top-down), or a person’s ability to detect rarely and unpredictably occurring signals occurring over a period of time, versus arousal attention (bottom-up). This article combines research from both animal and human studies in cognitive neuroscience into a complete and exact description of the neuronal networks ascribed to sustained attention (essential for successful academic performance). The researchers found evidence to conclude that sustained attention is ascribed to the right fronto-parietal-thalamic network, while arousal is controlled by the thalamic, midbrain, and reticular networks. By pinpointing these regions of the brain, more effective treatment for attentional disorders can be provided. While the article is very scientific, the researchers’ emphasis on studying each sub-process of attention and how they interact helps us to understand and appreciate individual learners.

Speech perception is the complement to visual perception. During speech perception, our auditory system translates sound vibrations into a sequence of sounds that we perceive to be speech. Visual cues contribute to speech perception. The researchers McGurk and McDonald showed participants a video of a person producing simple sounds, such as “gaga”. However, the researchers present different audio information along with the video, such as “baba”. The observer’s responses usually reflected a compromise between these two discrepant sources of information: “dada”. Here is a video clip that illustrates the McGurk effect. Turn up the volume and watch the video. What do you hear? Now, play it again and shut your eyes, what do you hear? You can even open and close your eyes while watching the video, the effect is still the same.

Recent research (Vroomen & Gelder, 2000) underscores the direct correlation between auditory and visual perception. The researchers concluded that it is eaiser to detect a visual stimulus when it is accompanied by an abrupt tone. This so-called "freezing" phenomenon in the visual modality was closely related to the organization of the sound in the auditory modality. This begs the question, can we utilize information from one sensory modality to organize our perceptions in the other modality? Read more about the study by clicking here.

With the “no child left behind” policy, test scores are foremost in educator’s minds. One study at Indiana University looked at the impact of visual and auditory cognition, measured through standard clinical tests, on predicting test scores (Watson, Kidd, Connell, Eddins, Gospel, Watson, Horner, Lowther, Rainey, & Kruger, 2003). The researchers found that the reading-related skills factor was the strongest predictor of reading performance and other areas of academic achievement. The second strongest predictor of reading and math achievement was the visual cognition factor followed by the verbal cognition factor. The weakest predictor of academic achievement was the speech processing factor.

By directing lessons to different learning modalities, teachers can utilize the codependency between visual and auditory perception. The use of the Internet as a teaching tool, however, raises another question: how can visual/verbal information presented via the WWW increase or restrict understanding? The Department of Education did a study in 1996 when the WWW was first gaining inroads into the classroom (El-Tigi, 1997). The purpose of the study was to examine student’s perceptions of the effectiveness of visuals in conveying the instructional message. The conclusion was that an educational web site's visual design greatly affects how people understand and use the information. Therefore, the web site should be designed using a learner-centered approach which takes into account the audience's age, learning preferences, and culture, among other factors. Click here to read more about the DOE study.

Welcome

Welcome to the blog I created for my Advanced Educational Psychology class! Here I will ponder selected theories of cognitive psychology, review the current scientific literature, and see how the information applies to my chosen career path as a school library media specialist. First, I believe, some definitions are in order.

From Margaret Maitlin’s, book Cognition:

Cognition is the acquisition, storage, transformation, and use of knowledge. Cognitive psychology can be considered a synonym for this mental activity, or it can refer to a particular theoretical approach to psychology, the cognitive approach. This approach emphasizes people’s knowledge and their mental processes. The cognitive approach is often contrasted with the behaviorist approach, which emphasizes observable behaviors, or the psychodynamic approach, which focuses on unconscious emotions.

From the American Library Association (ALA) web site:

Today's school library media specialist works with both students and teachers to facilitate access to information in a wide variety of formats, instruct students and teachers how to acquire, evaluate and use information and the technology needed in this process, and introduces children and young adults to literature and other resources to broaden their horizons. As a collaborator, change agent, and leader, the school library media specialist develops, promotes and implements a program that will help prepare students to be effective users of ideas and information, a lifelong skill.

Notice the similarity in the definitions for cognition and school library media specialist. Acquire and use information…transformation and change agent… If a library media specialist is to instruct students and teachers how to acquire and use information and serve as a change agent, then she should understand the mental activities surrounding the acquisition, transformation, and use of knowledge, don’t you agree?

The area of cognitive psychology is as broad as it is deep, so I can only begin to cover a subset of topics in the time and resources I have available. In order to narrow my focus, I chose the following set of questions to discuss on this blog.

Present, evaluate, and show the relation between the theory of semantic memory and working memory with perceptual processes: visual and auditory recognition. Show how the semantic memory could influence perceptual processes. What is the influence of working memory in perceptual processes? Show how the theories could be used in your future career. Evaluate how your knowledge about these theories influences the way you would explain different situations in your career.

I feel these theories are key to my purpose as a library media specialist, which is to provide many means by which students can learn about a subject. When a person takes in information, it is stored in semantic memory. How well this is retained in semantic memory can be influenced by how the information was presented (perception). And vice versa, what is already in semantic memory could influence how students they perceive additional information. Working memory grows during the elementary school years, so the stage of the student’s memory development needs to be considered when planning learning projects.

My next few posts will discuss the theory behind perception, working memory, and semantic memory. The posts will also review current literature on these topics from the perspective of how these cognitive processes influence student education and teaching methods.