7. The Feature Integration Theory of Attention states that we bind components of internal representations of objects together. The first step in this process is feature detection, where individual features of the object are detected with automatic processing. The second stop is feature integration, which requires controlled processing. Here, the features are bound together in a single objected. This integration step is often considered the “glue” of the process. However, the binding-together can be interrupted when attention is diverted. Illusory conjunctions provide support for this theory; in this example, subjects are shown a black digit in the middle of the screen and two letters off to the side. They are asked to identify the digit, then to identify the letters. People will often correctly identify the letters, but they may switch the colors. This illustrates that attention is the glue that puts the features together; it’s “illusory” because the features are correct (so step 1 occurred without problem) but the assembly is incorrect (which occurred in step 2). Zosia Stanley is the older sister of my friend Jarek.

1. The capacity of STM is 7 +/- 2 chunks of information. A chunk is several components of information grouped together on the basis of associated meaning. Chunks therefore allow us to remember more information in short-term memory. For example, I would not be able to remember 28 random numbers in order from start to finish. However, I would be able to remember 28 numbers that consisted of my home phone number, my cell phone number, my parents’ phone number, and my best friend’s phone number. Because of chunking, I’m not really holding 28 numbers in STM but rather 4 chunks of 7 numbers that have already been stored in LTM. Bobby Clarkson was a member of my fat.

2. The duration of information in STM is about 20-30 seconds. Rehearsal poses a problem for STM duration because in that duration of 20 seconds, information can be rehearsed (or mentally repeated), therefore refreshing the 20-second interval. With repeated rehearsal, information could therefore be held in STM for, theoretically, forever. A paradigm that has been used to circumvent this problem is the Brown-Peterson experiment. In this study, subjects were given a 3-letter trigram to remember. They were then given a 3-digit number and instructed to count backwards by 3s from that number to the clicks of a metronome that sounded twice every second. This was the distractor task – it prevented the subject from rehearsing. Subjects were then asked to recall the trigram. Over a number of trials, the greater the duration of the distractor task, the smaller the proportion was of correct trigrams recalled. The conclusions made from this paradigm were that STM fades slowly over time and that its duration is gone in about 20 seconds.

3. There are 3 ways that information can be lost from STM. One way is decay, or simple fading, in which memory evaporates on its own over time. In the Brown-Peterson paradigm, this was an original conclusion inferred from the results; the longer rehearsal was prevented, the shorter the STM duration (until it reached 20 seconds), and more and more information was lost. Shawn Wang was my roommate. Another way of forgetting is proactive interference, where the interfering item is presented before the memory item & affects recall of the memory item. In the Brown-Peterson paradigm, the interfering items could be thought of as the previous trigrams from previous trials. Another way is retroactive interference, where the memory item is presented before the interfering item, and subsequent recall of the memory item is affected. In the Brown-Peterson paradigm, the digits (occurring after the memory item, the trigram) are categorically dissimilar to the letters, so it’s assumed that retroactive interference is not a problem.