Category Archives: Graduate Coursework

Reaction to “A mechanical model for human attention and immediate memory” by Broadbent (1957)

Reaction to Broadbent (1957) by Richard Thripp
EXP 6506 Section 0002: Fall 2015 – UCF, Dr. Joseph Schmidt
September 15, 2015 [Week 4]

Broadbent (1957) presents a model for human attention conceptualized as a Y-shaped tube that receives balls that represent information. A flap divides the Y-connection, and various parallels between what would happen to the actual balls and to human attention and memory are proposed.

Broadbent could instead have used water flowing through a Y-connector as his analogy—the rate or constriction of flow could vary between pipes, for example. There are many analogies that could be used. Whether this is a good analogy is up for debate, but seeing that Broadbent had to attach numerous codicils (p. 206, 208, 210) and discusses many limitations (p. 213) and conceptual problems with his model seems to suggest it is questionable. His modified model in Figure 2 (p. 210) appears as a circuit, which models memory as a recurrent process, but is admittedly an unwieldy and difficult model, given the author’s humorous comments that the apparatus would need to be filled with acid to replicate the disappearance of a memory item by dissolving a ball. This model might be more detrimental than useful as a teaching tool, if it results in profound, lasting misconceptions. The author admits: “Certain properties of the model are likely to be misleading” (p. 213)—no kidding! I can only imagine that getting this published in 1957 was much easier than it would be now.

We are familiar with the idea of “semantically impoverished” stimuli—that stimuli such as colored boxes and abstract shapes are not as salient as real-world stimuli. When Broadbent clarifies that stimuli can bypass the Y tube “if they convey sufficiently little information” (p. 213), one wonders if he considered the distinction between semantically rich and semantically impoverished stimuli? Being that he goes on to discuss reflexes and generalize them to “voluntary” reactions, it appears the distinction was (momentarily) lost on him. Broadbent may have been a visionary if he replaced “convey[ing] sufficiently little information” with something like “requiring sufficiently little processing resources.” The quantity of information is not always the most important part—later on the same page, Broadbent makes the point that decimal digits (base 10) convey far more information than binary digits (base 2), and yet do not require much (or any) extra effort for our brains to remember (p. 213). Therefore, the Y tube model is grossly oversimplified—some balls may in fact be bigger than others, and some may require negligible resources.

Broadbent concedes the Y tube analogy is of “obvious absurdity” if one identifies it with the organism, rather than as a mechanical conceptualization for human attention and immediate memory (p. 213). He proposes the model is primarily for people who find the abstract theory “unintelligible”—and indeed, it may help them. However, individuals who have a rudimentary understanding of attention and memory may be better off skipping Broadbent’s paper, given that it may imbue them with gross simplifications, rather than refining their understanding.


Broadbent, D. E. (1957). A mechanical model for human attention and immediate memory. Psychological Review, 64(3), 205–215. doi:10.1037/h0047313

Reaction to “The cocktail party phenomenon revisited” by Wood & Cowan (1995)

Reaction to Wood & Cowan (1995) by Richard Thripp
EXP 6506 Section 0002: Fall 2015 – UCF, Dr. Joseph Schmidt
September 15, 2015 [Week 4]

Wood and Cowan (1995) indicate that they are following up and improving on an old research study that was “conducted rather casually” with a tiny sample size (p. 255). Wood and Cowan’s participants listened to two channels of unrelated, monosyllabic words with stereo headphones, and were asked to attend to and repeat (“shadow”) only the female voice, while being instructed to ignore the male voice in the left earpiece. Unbeknownst to them, the male voice would say their name at either the 4 or 5 minute mark, and the name of another “yoked control participant” at either the 4 or 5 minute mark (p. 256–57). In the experimental condition, 9 of 26 participants noticed their name in the irrelevant channel, and 5 of these 9 participants made a mistake in repeating one or more of the two words before or three words after, compared to a much smaller proportion of errors among the other participants (p. 258). Interestingly, the 9 who noticed had a much higher mean response lag on the second word after their name—approximately 950 ms as compared to 675 ms in the next highest category, possibly indicating distraction (p. 259).

While this may be a compact and nicely structured study, the generalizability is limited—it is not similar to the “cocktail party” analogy at all. All words used were monosyllabic, and participants were specifically selected who had monosyllabic names—a highly unrealistic scenario, given the plethora of common disyllabic names. The attended channel was always in a female voice and the irrelevant channel in a male voice—given that higher pitched voices may be easier to hear, it would have been interesting to see the authors switch this up. Both channels played words simultaneously and at a rate of exactly one word per second (p. 257), which is not generalizable to a cocktail party, nor even most human conversation. I was surprised that while the authors were careful to play half of participants’ names at the 4 minute mark and others at the 5 minute mark, they did not try switching the ears (the attended channel was always the right earpiece). Furthermore, the entire experiment was only 5 ½ minutes—placing the stimulus so late in playback could produce different results from placing it toward the middle or beginning, although a Fisher’s exact test indicated no difference between the 4 and 5 minute conditions.

I cannot understand why 5 participants were rejected due to not having yoked control participants (p. 256). Why not just select monosyllabic names at random from a list of common names? In fact, I am not sure of the necessity of having yoked participants at all—selecting names randomly could have worked for all participants, freeing the authors up to manipulate some other variable. The authors’ admit that “the order of words was otherwise [besides the insertion of two names] identical across participants” (p. 257), but this could have been varied by experimental condition. There is also a gender bias that is not addressed: 25 (73.5%) of participants are male and only 9 (26.5%) are female. The authors could have selected equal numbers per gender, and could have broken out the results by gender.

I would like to have seen more discussion regarding the fact that none of the 26 experimental participants recalled hearing the yoked control participant’s name. This may be an indicator that monosyllabic names and words are not differentiated by our brains like our name is, but this possibility was not explored. It would even be interesting to conduct an experiment where the irrelevant channel consisted primarily or completely of monosyllabic names, to see whether this is noticed and whether a similar proportion of participants notice their names. Notice that 85% of participants were not even able to recall a specific word from the irrelevant channel, and 62% did not volunteer that it was in a male voice, even though all were asked for information about the channel’s content (p. 257). Were some participants just listening better than others, or not following the directions precisely? Participants who noticed their names made fewer errors on average: 17.0 versus 20.5 (p. 257). While this difference was not significant, recall that participants who noticed their names made more errors in the three words immediately after their names (p. 258–59). Perhaps if the errors immediately after their names were partialed out, a significant difference would have been found? We may never know.

There are many other conditions the researchers could have tried. While a sample of 34 is generally sufficient for a cognitive experiment, this was a very short and simple experiment that required little time or energy from participants. It would be nice to see the authors use a larger sample size and try more interesting experimental conditions, rather than rejecting 6 participants (p. 256) due to a shortage of names (n = 5) and due to an experimenter mistakenly letting the cat out of the bag (n = 1), albeit the latter is my speculation.


Wood, N., & Cowan, N. (1995). The cocktail party phenomenon revisited: How frequent are attention shifts to one’s name in an irrelevant auditory channel? Journal of Experimental Psychology, 21(1), 255–260.

Reaction to “A review of visual memory capacity” by Brady, Konkle, & Alvarez (2011)

Reaction to Brady, Konkle, & Alvarez (2011) by Richard Thripp
EXP 6506 Section 0002: Fall 2015 – UCF, Dr. Joseph Schmidt
September 7, 2015 [Week 3]

Brady, Konkle, and Alvarez (2011) provide a thorough, though not exhaustive, review of visual memory research, broken down into convenient sections and subsections. Overall, two main sections regarding visual working memory and visual long-term memory investigate the ideas and research about various aspects of these systems, such as memory fidelity (p. 2–5, 13–15), basic units of representation (p. 5–7), interactions (p. 7–10, 23–25), and the effects of stored knowledge (p. 10–12, 15–19). Generally, these topics were treated separately with regard to working memory and long-term memory, which is a traditional distinction that is advantageous for conceptualization, but is of uncertain validity (p. 23–25). Based on an abundance of cited research, several themes emerged. With respect to working memory, capacity may be issue of both quality (fidelity) of memory and quantity of items remembered (p. 12). Structured representations and ensemble effects should be considered, meaning that information is stored in multiple and interacting layers (p. 10, 12). Long-term memory is surprisingly robust, especially with stimuli that are both semantically rich and real-world, supposedly because real-world scenery allows us to employ “passive episodic retrieval”, unlike “semantically impoverished stimuli” such as colored squares (p. 24). Overall, both working visual memory and long-term visual memory are more intricate and inter-dependent than once thought, which makes compartmentalizing any one subcomponent, and experimental research in general, highly difficult.

I found the results regarding long-term memory experiments interesting—I did not recall that our long-term memory is near-perfect for 10,000 items, as long as those items are unique and meaningful (p. 22). The authors did a good job of organizing the subjects and materials into numerous headings and subheadings, which made this review feel less onerous than many experimental research articles regarding cognition.

As a person with some computing knowledge, I liked the analogy of memory to a USB drive (p. 2), but found it constrained by technical inaccuracies. Saying that “the number of files that can be stored is limited only by the size of those files” with respect to a USB drive (p. 2) is inaccurate, given that it is constrained by the cluster size of the file system. USB flash drives typically use the FAT or FAT32 file system with cluster sizes of 4096, 8192, or 16,384 bytes (depending on drive capacity). Any file occupies the nearest higher discrete number of clusters—the author’s example of a 16 × 16 pixel image would typically take up at least 4096 bytes, even though the actual file would be 768 bytes or less. Conceptually, this adds a more complicated layer to the analogy that might actually be relevant to visual working memory—perhaps there is a lower bound on the space an item occupies, regardless of further reductions in fidelity? This characterization offers an appealing middle ground between continuous and discrete visual working memory models, which was not directly addressed by the authors (and may not yet be addressed in the literature).

Expanding on computing analogies, the authors missed a great chance to compare the concept of structured representations to progressive image rendering. Progressive JPEG images look blocky at first, and then gradually appear clearer as more data is received and decoded. This is similar to the idea of a “hierarchically structured feature bundle” (p. 7) where low-level features at the bottom level coalesce into a complete object representation through multiple, structured levels of data. Progressive image rendering shares remarkable commonalities with structured memory models (p. 10), and may even provide a conceptual framework to explore and develop visual working memory models.


Brady, T., Konkle, T., & Alvarez, G. A. (2011). A review of visual memory capacity: Beyond individual items and toward structured representations. Journal of Vision, 11(5), 1–34. doi:10.1167/11.5.4

Reaction to “The psychology of memory” by Baddeley (2004)

Reaction to Baddeley (2004) by Richard Thripp
EXP 6506 Section 0002: Fall 2015 – UCF, Dr. Joseph Schmidt
September 2, 2015 [Week 2]

Baddeley (2004) discusses the contemporary research and competing models on how various aspects of human memory operate. Based on research, a general model dividing declarative (explicit) and nondeclarative (implicit) memory has achieved broad acceptance (p. 6)—however, the details remain up for field testing and debate, such as which distinct types of memory exist, how they overlap, what category or categories they fit into, and how these types of memory relate to everyday life. Intense inquiry, including studying patients with brain damage, memory deficits, and amnesia, has greatly refined the psychology of memory; it is now regarded as a complex and nuanced system that interacts, both within its components (short-term memory, long-term memory, and their subtypes) and with the external environment. We have progressed greatly in the past century—we no longer regard memory as a monolithic faculty, nor do we take semantic memory for granted as psychologists did prior to the 1960s (p. 6).

Baddeley has produced a literature review that is engaging and highly readable. He has done a great deal of research in this area—he references 15 articles for which he was the primary author, and seven more articles that he co-authored. His scientific humility is shown in areas where he presents competing viewpoints or suggests reading other authors who have expanded and refined his works, such as the expansions by Vallar & Papagno (2002) and Della Sala & Logie (2002) on the Baddeley & Hitch (1974) model of working memory (Baddeley, 2004, p. 3-4). He is cautious to not pick sides or make definitive judgments—this can be seen in phrasing such as “among the strongest arguments” (p. 1), “it is generally accepted” (p. 6), and “one view is that” (p. 8). This concern for impartiality, rigor, and detail endears Baddeley to the reader and shows him leading by example, encouraging the reader to consider all the evidence and potential unknowns.

Baddeley presents the viewpoint of Squire (1992), that semantic memory is simply the result of episodic memories for which the brain has lost context (p. 6). Similarly, in a lecture on April 21, 2015, to a Developmental Psychology graduate class, Professor Sims proposed the argument that “wisdom” might be characterized as knowledge without context, where the source of the knowledge has simply been forgotten, while the knowledge remains. Forgetting where, how, or from whom you learned something does not mean the episode or source does not exist, but it does mean it may be, for practical purposes, irretrievable. Alternately, the acquisition may have been spread out over a long period of time, making it hard to quantify. However, it is apparent why we may want to attribute this to experience or wisdom rather than memory loss—it is a much more palatable and polite designation. Squire’s characterization of semantic memory provides a potential explanation for how we learn language, culture, and habits—not in a singular episode, but slowly, over time, and typically without conscious consideration.

I was delighted by the discourse on prospective memory, which is an area where the elderly are paradoxically better than young people (Baddeley, 2004, p. 9), perhaps because they are more cautious about writing things down, keeping a schedule, setting alarms, and recognizing that their memory is highly fallible. On the other hand, young people are often overly trusting of their own ability to remember, to hilarious or disastrous consequences, such as showing up to class on Labor Day, or forgetting the due date for a course project. These and other “everyday” problems are more interesting to laypersons than laboratory settings, and for this reason, naturalistic materials are even being adopted in controlled settings (p. 11).


Baddeley, A. D. (2004). “Chapter 1: The psychology of memory.” In A. D. Baddeley et al. (Ed.), The essential handbook of memory disorders for clinicians. Chichester, England: John Wiley & Sons.

Effective Prioritization and Establishing Stewardship Agreements (Covey’s 7 Habits)

Written for my Learning Theories Applied to Instruction and Classroom Management graduate class (EDF 6259; professor Kay Allen) at University of Central Florida on 2015-04-13 (Spring 2015 semester), this assignment gave me the opportunity to read and write about Seven Habits of Highly Effective People as part of my graduate coursework.

Richard Thripp
Grade Contract: A

1. Seven Habits of Highly Effective People

a. Important Concept One: Effective Prioritization:

Covey presents the idea that the activities prioritized by most people are often somewhat trivial or meaningless, yet come with urgent deadlines and social pressure. Similarly, we pressure ourselves to get our “to-do list” done for the day, even when the tasks on it fail to contribute to the “big picture”: our lifelong goals and priorities. Activities that are important, yet not urgent, are where we should place more focus, even at the expense of activities that seem urgent to others. This is because prioritizing vital tasks that relate to our personal mission has better and more important long-range benefits for ourselves and our leadership potential. Most daily planners and email or inbox workflows focus on tasks that are urgent but not important, and while solving such tasks may meet others expectations or make us “feel” busy, in the long run they are inconsequential (Covey, 1989). Leaders may gain the respect of others by confidently refusing requests and assignments that are urgent yet not important, which also frees them up to focus on what really matters. A single step one can take in this direction is to jettison the telephone (or delegate answering it to someone else). A ringing telephone is a highly salient example of an urgent, yet frequently unimportant distraction.

In the classroom, effective prioritization might involve talking more about underlying themes or overarching mathematical concepts and principles. The drill of rote learning might appear to fill the urgent need of improved standardized test performance, yet if you start early in the school year, it is possible that higher-order instruction might result in both improved conceptual understanding and higher test scores.

b. Important Concept Two: Establishing Stewardship Agreements:

Stewardship delegation has a large upfront cost—placing work such as photography or yard work (Covey, 1989) under the control and self-direction of children, for example, requires that both the leader and steward establish guidelines and desired results, as well as leading the steward to take ownership and personally identify with the work. This is applicable to children and adults alike; many corporations and institutions employ “gofer delegation,” where employees are told how to do every task, and never take initiative to develop their own methods. More importantly, they do not feel their work is a part of them (low commitment), and thus are ineffective workers in the long run. Instead, if individuals are given parameters and pitfalls to avoid, while being allowed to develop their own methods to produce the desired results, they will eventually become much more effective due to being self-directed and feeling personally responsible. This form of delegation is much more “hands off” and allows the steward to be his or her own boss, which additionally frees up time for the leader to work on more important activities, such as establishing new stewardship arrangements with other employees.

In the classroom, a stewardship agreement might be presented with regard to children’s binders or notebooks. Surprisingly, when I observed a 5th grade classroom at a low-SES public elementary school in 2011, I saw the teacher placing items in students’ 3-ring binders for them, and even filling out parts of their worksheets. Getting children to manage and take pride in their binders through stewardship delegation entails more work upfront, but has large benefits. Children may become proud of their organization skills and more interested in reviewing the homework and curriculum materials in their binders, and the teacher will not have to micro-manage or worry about these students abusing or losing their binders.

c. Share at least one way in which one or both of the concepts has/have informed you in your professional practice.

Effective prioritization is an ongoing battle for me, but I have felt more apt to work on complex projects ahead of schedule this semester, after listening to Seven Habits of Highly Effective People in audio format. Further, I have passed up many urgent but unimportant requests, such as requests from friends for help with physical labor, copy-editing, or low- or un-paid freelance photography work. In fact, some friends have actually come to expect me to decline helping them over the past two months, and have stopped sending me their urgent requests. While declining urgent but unimportant engagements is but one aspect of Covey’s model, I believe it is an important first step for me. Developing this habit will benefit my career, allow more time for my hobbies, and promote mutually beneficial social relationships.


Covey, S.R. (1989). The seven habits of highly effective people: Restoring the character ethic. Thorndike, ME: G.K. Hall & Co.