Cognitive Psychology

Source: Laboratory of Jonathan Flombaum—Johns Hopkins University It is a well-known fact that the human ability to process incoming stimuli is limited. Nonetheless, the world is complicated, and there are always many things going on at once. Selective attention is the mechanism that allows humans and other animals to control which stimuli get processed and which become ignored. Think of a cocktail party: a person couldn’t possibly attend to all of the conversations taking place at once.

Source: Laboratory of Jonathan Flombaum—Johns Hopkins University The ambition of experimental psychology is to characterize the mental events that support the human ability to solve problems, perceive the world, and turn thoughts into words and sentences. But people cannot see or feel those mental events; they cannot be weighed, combined in test tubes, or grown in a dish. Wanting to study mental life, nonetheless, Franciscus Donders, a Dutch ophthalmologist in the early 1800s, came up with a...

Source: Laboratory of Jonathan Flombaum—Johns Hopkins University How do people find objects in cluttered visual scenes? Think, for example, of looking for keys on a messy desk, finding the ripest-looking fruit at the grocery store, locating your car when you can’t quite remember where you parked it, or finding an old friend at an airport exit gate. Clearly, an understanding of visual perception is going to play a role in any answers, and more specifically, an understanding of visual attention...

Source: Laboratory of Jonathan Flombaum—Johns Hopkins University As an Assistant Professor of Psychology and Cognitive Science at Johns Hopkins University, I teach Introduction to Cognitive Psychology. This large class primarily consists of freshman and sophomores majoring in related fields, like Psychology, Neuroscience, or Cognitive Science. One of the challenges I face in the classroom is teaching students to appreciate how data are obtained in the process of performing experiments.

Source: Laboratory of Jonathan Flombaum—Johns Hopkins University Why do people have two forward-facing eyes? By presenting the brain with two ever so slightly different images it becomes possible to comprehend visual problems that are far more difficult to process through a single eye. Chief among these is the problem of 3-D perception, seeing the world in three dimensions, despite retinal inputs in only two dimensions. What happens if each eye receives two completely different images? That...

Source: Laboratory of Jonathan Flombaum—Johns Hopkins University In a staggeringly complex and engaging world, it is crucial to selectively process some stimuli at the expense of others. Experimental psychologists call this ability attention. Specifically, visual attention refers to the ability to selectively process aspects of a visual scene. Many paradigms used to study visual attention involve brief, punctuated, and repeated trials. However, everyday situations often place sustained demands...

Source: Laboratory of Jonathan Flombaum—Johns Hopkins University A common carnival game is to ask people to guess the number of jellybeans packed into a jar. The chances that anyone will get the exact number right are low. But what about the chances that someone will guess 17 or 147,000? Probably even less than the chances of guessing the correct answer; 17 and 147,000 just seem irrational. Why? After all, if the beans cannot be taken out and counted one-at-a-time, how can someone tell that an...

Source: Laboratory of Jonathan Flombaum—Johns Hopkins University Visual mental imagery refers to the ability to conjure images in one’s mind’s eye. This allows people to process visual material above and beyond the constraints of a current point-of-view; for example, a person could imagine, using their mind’s eye, how something might look in a different color, or what it would look like if it were made from a different material or rotated and seen from a different perspective. Mental imagery...

Source: Laboratory of Jonathan Flombaum—Johns Hopkins University What’s the value of a dollar? Currencies store value to facilitate trade. Implied in any economic transaction is the value of a unit of currency. But what is the subjective value of a dollar? For a long time, economists assumed the answer to this question to be, specifically, that a dollar has a value determined by the market and that the subjective value of a dollar is always that, more or less. Beginning in the early 1970s,...

Source: Laboratory of Jonathan Flombaum—Johns Hopkins University Why is it relatively hard to remember everything on a shopping list if it includes more than just a handful of items? Why is it possible to remember a phone number that one just heard, but not two or three phone numbers at once? Why is it difficult to remember names when several new people are introduced at the same time? The answer has to do with the fact that over short-durations people rely on a specialized memory system...

Source: Laboratory of Jonathan Flombaum—Johns Hopkins University Human memory is limited. Throughout most of its history, experimental psychology has focused on investigating the discrete, quantitative limits of memory—how many individual pieces of information a person can remember. Recently, experimental psychologists have also become interested in more qualitative limits—how precisely is information stored? The concept of memory precision can be both intuitive and elusive at once. It is...

Source: Laboratory of Jonathan Flombaum—Johns Hopkins University Human memory seems to work in two broad ways. Like modern computers, the human mind has explicit, or declarative, memory: ask a question, and a person gives the best answer they can. Input a query, and a computer program returns the contents of the relevant parts of its stored memory. Humans also have a second kind of memory system, one not really typical of computers, one that experimental psychologists call implicit. Implicit...

Source: Laboratory of Jonathan Flombaum—Johns Hopkins University Long-term memory is a critical feature of human cognition, and it has been a prominent focus of research in experimental psychology. Many paradigms designed to tap long-term memory rely on asking participants to learn or study content, then test memory about that content. This is a good approach if one wants to understand how memory supports educational achievement, for example, where explicit study is part of the process. But,...

Source: Laboratory of Jonathan Flombaum—Johns Hopkins University The visual environment contains massive amounts of information involving the relations between objects in space and time; certain objects are more likely to appear in the vicinity of other objects. Learning these regularities can support a wide array of visual processing, including object recognition. Unsurprisingly, then, humans appear to learn these regularities automatically, quickly, and without conscious awareness. The name...

Source: Laboratory of Jonathan Flombaum—Johns Hopkins University Colloquially, the terms learning and memory encompass a broad range of behaviors and mental systems, everything from learning to tie a shoe to mastering calculus (and a lot in between). Experimental psychologists have divided up learning mechanisms into groups that seem to have different properties, and that seem to rely on different brain systems. A major division is between declarative and non-declarative memory, roughly, the...