Memory for faces is better than memory for other objects, but only under specific conditions

An article written by me, my advisor, and another professor at George Mason University just got accepted for publication in the journal Cognition:

Wong, J. H., Peterson, M. S & Thompson, J. C. (in press). Visual working memory for objects from different categories: A face-specific maintenance effect. Cognition.

Abstract: The capacity of visual working memory was examined when complex objects from different categories were remembered. Previous studies have not examined how visual similarity affects object memory, though it has long been known that similar-sounding phonological information interferes with rehearsal in auditory working memory. Here, experiments required memory for two or four objects. Memory capacity was compared between remembering four objects from a single object category to remembering four objects from two different categories. Two-category sets led to increased memory capacity only when upright faces were included. Capacity for face-only sets never exceeded their non-face counterparts, and the advantage for two-category sets when faces were one of the categories disappeared when inverted faces were used. These results suggest that two-category sets which include faces are advantaged in working memory but that faces alone do not lead to a memory capacity advantage.

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So what does this mean? Other research has demonstrated that visual working memory seems to be able to hold more information about faces than other objects such as cars or inverted faces (which are processed in an entirely different manner from faces). This is a sensible conclusion, as faces have been shown to be processed uniquely in terms of perception. However, this is the first evidence that faces are unique in terms of working memory.

Our evidence supports that conclusion but also narrows it down. We found no specific advantage for faces if you have to remember a bunch of faces together or a bunch of other objects together (all houses, butterflies, or bodies in motion). This was seen for remembering two or four objects. However, if you have to remember two objects from two categories - two faces and two houses, for example - your memory was better than for four objects from the same category. Additionally, this only happened when faces were part of the set. Remembering two butterflies and two houses together did not lead to better memory.

Therefore, faces are unique in memory, but an advantage is only seen when faces are remembered with non-face objects. Why? It’s possible that there are distributed (but overlapping) representations of faces and all other objects, almost like a Venn diagram with two partially overlapping circles. When only faces or only other objects are remembered, only one of the two circles is activated in support of memory. When faces and other objects must be remembered, both circles can activate, increasing memory capacity. This theory, however, is for another experiment that we’re working on.

By the way, this is the same research that was presented at the 2008 Vision Sciences Conference held last May. Click the poster image below for the PDF:

Vision Sciences 2008

I am at the Vision Sciences Society conference right now in Naples, FL. It’s my fourth VSS, and the presentations are of high quality and the beaches are of the same high standard. I’m presenting two posters at the conference.

The first is a study I’m doing with my labmates and Carl Smith (Evaluating Design) looking at eye movements in experts and novices while they view a movie of the first-person shooter Quake 4 and have to detect targets. The big picture is that more experienced players make fewer eye movements for longer periods of time. This reflects previous research that suggests experts have a larger functional field of view, so they can extract more information from the periphery than novices.

The second poster are a series of studies I worked on with my advisor and another faculty member at George Mason University. We examined the effect of holding similar and dissimilar items in working memory to determine how the capacity of visual working memory changed when you had to remember sets of items from different categories. The interesting result is that remembering 2 objects from 2 separate categories (4 total object) led to higher working memory capacity than 4 objects from a single category, but only if faces were part of the two-category set. This is not due to a general “faces are special” effect, as memory capacity for two or four faces alone was never greater than memory for other object classes.

As I attend other interesting talks and posters, I hope to write about them here. Stay tuned!

Outsourcing Your Brain

The New York Times has a great column today called The Outsourced Brain (PDF). The columnist bought a GPS device which enabled him to forget any and all geographical knowledge. An exaggeration, sure, but how many of us remember phone numbers anymore when we have them all in our cell phone? I only remember a couple - the rest are in my phone and on my computer. I’m guessing that most people are the same way.

I often have this discussion when I teach Long Term Memory in my Cognitive Psychology class. My students worry about whether our LTM is not as sharp because we don’t have to remember as much information anymore. It’s a valid concern, I think. With pervasive access to Google and Wikipedia, who needs to memorize facts? It’s the difference between a closed-book exam and an open-book one!

I don’t know of any research that has shown that our memory has gotten any worse over the past 10 years, or that our students are getting dumber because they do not have to memorize as many facts. The argument that I make is that our memory is just as good as before, but the skills related to memory have changed. We may not be as good at remembering strings of arbitrary digits, but we can remember the many confusing steps for programming a new number into our phone. And in today’s world, what’s more important: remembering a bunch of random characters, or being able to deftly navigate through new user interfaces?

This is all about offloading menial cognitive tasks that we’re not very good at and replacing them with tasks that we are good at. Not so good at random numbers, great at visual search, problem solving, and decision making. This principle is taken advantage of by David Allen, the Getting Things Done guru. Instead of tying your brain up with menial tasks like remembering a small to do item, the goal is to write them down. And anything that can be done in less than 5 minutes should be done immediately so you can check them off. It’s about giving your brain tasks it’s good at by offloading tasks that are too simple and breaking down tasks that are too complicated. Well, David Allen can probably explain it best:

Outsourcing Your Brain. Don’t think about it. Write it down.

Flash drives, old computers, and Windows

There are a healthy number of older PCs at work that I have to use sometimes. These aren’t old 386s - just older Pentium 4s or the occasional Pentium 3. Nonetheless, they all have USB 1.1, which is slower and older than the current USB 2.0 standard. When I plug my USB flash drive into one of these older computers, I get a message:

OK, fine. It can perform faster! I’ll click on the balloon:

So there are no faster ports on my computer. Even though Windows said that it can perform faster. In reality, it can’t. You know what the worst part of it is? Every time I plug my flash drive in, I GET THE SAME ALERT MESSAGE. Therefore, every time I plug my flash drive in, I get interrupted from my train of thought, have to deal with the alert box, and try to resume my original task. This is not easy (Altmann & Trafton, 2002), and it’s totally annoying.

Today, I wanted to eject my flash drive (named JasonFlash) from the computer, so I clicked in the Safely Remove Hardware button in the tray, and I get:

There’s an external hard drive (named Seagate) attached to the computer. Which one do I want to eject? I don’t have a clue! Windows lets users give their devices names. Maybe Windows should use those names sometimes - give us some retrieval cues so we know which device is the external hard drive that should never be removed and the flash drive that goes everywhere with me.

I have a feeling this is the first of many posts about Windows.

Amazon.com Item Page Clutter

Amazon.com is an unholy mess when shopping for anything, including books! Let’s say you’re looking for the first Harry Potter book. The URL is http://www.amazon.com/Harry-Potter-Sorcerers-Stone-Book/dp/0590353403/ref=pd_bxgy_b_text_b/002-6815992-5484811?ie=UTF8&qid=1184898138&sr=1-3, which is already bad. But if you want a hard copy, it will take ten pages of paper to print out! TEN PAGES of content for Harry Potter. What’s in those ten pages, you ask? Well, the categories are:

Better Together Customers Who Bought This Also Bought Editorial Reviews Product Details What Do Customers Ultimately Buy After Viewing Items Like This? Help others find this item Tags customers associate with this product Are you the publisher or author? Learn how Amazon can help you make this book an eBook. Rate this item to improve your recommendations Customer Reviews Customer Discussions Product Information from the Amapedia Community Listmania! So You’d Like to… Your Recently Viewed Items Look for Similar Items by Category Look for Similar Items by Subject Feedback Your Recent History

That’s twenty categories. Twenty! Working memory, depending on who you ask, can hold four (Cowan, 2001) to seven (Miller, 1956) items, and attention can only process so much of the visual field at a time (Rensink, O’Regan & Clark, 1997). Yet Amazon decides to give a topic like “Are you the publisher or author?” valuable space just in case J. K. Rowling stops by.

What to do? Well, that’s easy.

• Table of contents at the top of the page to easily jump to specific sections
• Cut down on the categories - which ones do users really need?
• Allow user-selectable categories. Amazon already tracks so much about shopping habits, they should track site preferences.

A simple survey would likely suffice, but so would a task analysis or even an eyetracking study. I’d bet that the eyes would move all around the page but never fixate for very long, meaning that the user was having trouble focusing on one particular piece of information - there’s just too much. Amazon is great for finding an amazing array of books and everything else. Now they should focus on not presenting an overwhelming array of information about products to the user.