Name: Tess Bartell PSY 250 Fall 2014 Lab 1 Visual Search Our ability to recognize complex patterns requires attention. For example in the demonstration of Infinite Maze by Mathôt and Danes (2014) at the Best Illusion of the Year Contest, the maze that the pac-man travels is always changing after the pac-man moves past that region. People do not notice this if they are focused on directing the pac-man. It has been theorized that pattern recognition requires two processing: pre-attentive and attentive. The pre-attentive process makes all the features in a visual display available immediately. However people can not determine which features go with each other. To recognize complex objects (defined by more than a single feature such as a conjunction or combination of features) attention has to be applied to individual patterns. As a consequence the more objects that are present the longer it takes to recognize the presence of a particular object. This is not the case when searching for an object that could be defined by a single feature like hot pink.
For this lab students should go to gocognitive.net and select the visual search demo. Please click on or select the rotating shapes with 144 trials. The task is to indicate by pressing the / key or z key if a predefined target is present or not. The same object will be the target throughout the lab. After completing all 144 trials, the results will appear.
1. Complete the following table. (2 pts)
Table 1.
Average Response Latency (ms) as a function of Search Type, Target, and Set Size

Set Size
Search Type
4
8
16
32
Single Target

Present
766.71
933.86
1013.14
1046.86
Absent
822.42
717.43
775.43
965.71
Conjunctive Target

Present
822.42
1066.86
992
1644.57
Absent
1036.57
1139.86
1230.14
1323.14
2. Identify one of the independent variables. (1 pt) The type of visual exercise chosen.

3. What was the hypothesis supported by your data? Please refer to the numerical data in your answer. (2 pts) For the most part, the measurements line up with the hypothesis that it takes longer to recognize an object among many, each time extending as more objects are added. When there was more than one target to identify, the times were a little longer than identifying only one target. In each situation, the most time was taken when there were 32 objects, the most that were shown in the examples.

4. Describe a situation when you would be doing a single feature search in your daily life. (2 pt) Looking for a coat in my closet to wear. I only have one coat hung among my shirts, so it would only be one thing I'm searching for.

5. Please read Wolfe, J. M. (2012). Saved by a log: How do humans perform hybrid visual and memory search? Psychological Science, 23(7), 698-703. doi:10.1177/0956797612443968. It is on D2L. What was a dependent variable in Experiment 1? (1 pt)
Memory set.

6. What was Wolfe’s conclusion about the efficiency of searching for known objects? (2 pts)
Those with better memory had an easier time finding the known objects.