Neuro Summary 4

In the April 2015 edition of the Journal of Neuroscience, Kait Clark, L. Gregory Appelbaum, Berry van den Berg, Stephen R. Mitroff, and Marty G. Woldorff, published an article about the effects that practice has on ones ability to perform visual search tasks1. In the article titled, “Improvement in Visual Search with Practice: Mapping Learning-Related Changes in Neurocognitive Stages of Processing,” the research team was able to evaluate the changes in response time during a visual search after processing.
The research team defined a visual search as “the process of detecting target items among distractors.” The ability for a human to perform such a task is very important. There are a lot of different processes that must be involved in the brain for a visual search to take place. These processes include, sensory analysis of the scene, orienting of visual attention, working memory, target discrimination, and decision/response processes. To access the change in the participant’s ability or speed of responding to a visual search, the research team conducted an experiment in which the participant was presented with a visual field filled with blue ellipses oriented either vertically or horizontally. The participant would watch the screen and certain ellipses would turn green and others would turn red. The green ellipse was the relevant marker and the red an irrelevant nontarget marker. As the green ellipse appeared, the participant would push a button corresponding to the orientation of the ellipse. The speed of response was recorded on the first day and then again at the end of the experiment, 5 days later. Each participant practiced for an hour each day that the experiment was in progress.
The results of the experiment supported the hypotheses of the research group that response time would decrease while the accuracy would be maintained. Response time average for the participants decreased from approx. 550 ms to 470 ms from the first session to the fifth. The accuracy of the participants choosing correctly actually increased from approx. 88 percent in the first session to 90 percent in the fifth session. The researchers reported that “in